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-rw-r--r--Build/source/texk/web2c/mplibdir/am/mplib.am52
-rw-r--r--Build/source/texk/web2c/mplibdir/avl.c2636
-rw-r--r--Build/source/texk/web2c/mplibdir/avl.h467
-rw-r--r--Build/source/texk/web2c/mplibdir/lmplib.c1238
-rw-r--r--Build/source/texk/web2c/mplibdir/memio.w405
-rw-r--r--Build/source/texk/web2c/mplibdir/mp.w26427
-rw-r--r--Build/source/texk/web2c/mplibdir/mpost.w939
-rw-r--r--Build/source/texk/web2c/mplibdir/mpxout.w4312
-rw-r--r--Build/source/texk/web2c/mplibdir/psout.w6246
-rw-r--r--Build/source/texk/web2c/mplibdir/svgout.w1314
-rw-r--r--Build/source/texk/web2c/mplibdir/tfmin.w242
11 files changed, 44278 insertions, 0 deletions
diff --git a/Build/source/texk/web2c/mplibdir/am/mplib.am b/Build/source/texk/web2c/mplibdir/am/mplib.am
index 12f7dc33e13..c979b25f7d8 100644
--- a/Build/source/texk/web2c/mplibdir/am/mplib.am
+++ b/Build/source/texk/web2c/mplibdir/am/mplib.am
@@ -1,2 +1,54 @@
## texk/web2c/mplibdir/am/mplib.am: Makefile fragment for MetaPost.
+## metapost
+##
+bin_PROGRAMS += newmpost
+
+EXTRA_PROGRAMS += newmpost
+
+EXTRA_LIBRARIES += libmplib.a
+
+newmpost_c_h = mpost.c mpxout.c
+newmpost_web = mplibdir/mpost.w mplibdir/mpxout.w
+
+newmpost_CPPFLAGS = -I. -I$(srcdir)/mplibdir
+newmpost_DEPENDENCIES = libmplib.a
+newmpost_LDADD = libmplib.a $(KPATHSEA_LIBS) -lm
+newmpost_SOURCES = $(newmpost_c_h)
+
+$(newmpost_c_h): mpost-ctangle libmplib.a
+mpost-ctangle: ctangle$(EXEEXT) $(newmpost_web)
+ CWEBINPUTS=$(srcdir)/mplibdir $(ctangle) mpost.w
+ CWEBINPUTS=$(srcdir)/mplibdir $(ctangle) mpxout.w
+ echo timestamp >$@
+ touch $(newmpost_c_h)
+
+DISTCLEANFILES += $(newmpost_c_h) mpost-ctangle
+
+## These files are mutually dependent
+libmplib_c_h = mp.c mplib.h mpmp.h mppsout.h psout.c mplibps.h svgout.c memio.c tfmin.c
+libmplib_true_c = mplibdir/avl.h mplibdir/avl.c
+libmplib_web = $(libmplib_true_c) mplibdir/mp.w mplibdir/psout.w
+libmplib_web += mplibdir/svgout.w mplibdir/memio.w mplibdir/tfmin.w
+
+libmplib_a_CPPFLAGS = -I. -I$(srcdir)/mplibdir
+libmplib_a_SOURCES = $(libmplib_c_h) $(libmplib_true_c)
+
+$(libmplib_c_h): mplib-ctangle $(libmplib_true_c)
+mplib-ctangle: ctangle$(EXEEXT) $(libmplib_web)
+ CWEBINPUTS=$(srcdir)/mplibdir $(ctangle) mp.w
+ CWEBINPUTS=$(srcdir)/mplibdir $(ctangle) psout.w
+ CWEBINPUTS=$(srcdir)/mplibdir $(ctangle) svgout.w
+ CWEBINPUTS=$(srcdir)/mplibdir $(ctangle) tfmin.w
+ CWEBINPUTS=$(srcdir)/mplibdir $(ctangle) memio.w
+ echo timestamp >$@
+ touch $(libmplib_c_h)
+
+EXTRA_DIST += $(libmplib_web)
+
+DISTCLEANFILES += $(libmplib_c_h) mplib-ctangle
+
+# only used by luatex, perhaps should not be mentioned here
+EXTRA_DIST += mplibdir/lmplib.c
+
+
diff --git a/Build/source/texk/web2c/mplibdir/avl.c b/Build/source/texk/web2c/mplibdir/avl.c
new file mode 100644
index 00000000000..a8421d4c93d
--- /dev/null
+++ b/Build/source/texk/web2c/mplibdir/avl.c
@@ -0,0 +1,2636 @@
+
+/* pyavl -- File "avl.c" */
+
+/* AVL trees with RANK field and parent pointers */
+
+#include "avl.h"
+
+#ifdef AVL_SHOW_ERROR_ON
+#define AVL_SHOW_ERROR(fmt,arg) fprintf(stderr, "! avl.c: " fmt, arg)
+#else
+#define AVL_SHOW_ERROR(fmt,arg) (void) (fmt), (void) (arg)
+#endif
+
+void *
+avl_default_item_copy (const void *item)
+{
+ return (void *) item;
+}
+
+void *
+avl_default_item_dispose (void *item)
+{
+ return (void *) NULL;
+}
+
+#ifndef MPW_C
+typedef uint32_t rbal_t; /* integral type to encode rank and skew bits */
+#else
+typedef UInt32 rbal_t;
+#endif
+
+/*
+ * avl_node structure
+ */
+
+typedef struct avl_node
+{
+ struct avl_node *sub[2];
+ struct avl_node *up;
+ rbal_t rbal;
+ void *item;
+}
+avl_node;
+
+/*
+ * avl_tree structure
+ */
+
+struct avl_tree_
+{
+ avl_node *root;
+ avl_size_t count; /* how many nodes in tree rooted at [root] */
+ avl_compare_func compare; /* compare items */
+ avl_item_copy_func copy;
+ avl_item_dispose_func dispose;
+ avl_alloc_func alloc; /* to allocate memory (same signature as malloc) */
+ avl_dealloc_func dealloc; /* to deallocate memory (same signature as free) */
+ void *param;
+};
+
+#define Item_Compare(cmp, tree, item1, item2)\
+ (*cmp)(tree->param, item1, item2)
+
+/* patches (November 2004) */
+
+#if AVL_CMPERR != 0
+#define CMPERR_CHECK__FIND(param) if (avl_errcmp_occurred(param)) return NULL
+#define CMPERR_CHECK__INDEX(param) if (avl_errcmp_occurred(param)) return 0
+#define CMPERR_CHECK__SPAN(param) if (avl_errcmp_occurred(param)) return -2
+#define CMPERR_CHECK__INS(param) if (avl_errcmp_occurred(param)) return -2
+#define CMPERR_CHECK__DEL(param) (avl_errcmp_occurred(param) ? -2 : 0)
+#define CMPERR_CHECK__SPLIT(param) if (avl_errcmp_occurred(param)) return -2
+#define CMPERR_CHECK__VERIFY(param) && (!avl_errcmp_occurred(param))
+#else
+#define CMPERR_CHECK__FIND(param) (void) param
+#define CMPERR_CHECK__INDEX(param) (void) param
+#define CMPERR_CHECK__SPAN(param) (void) param
+#define CMPERR_CHECK__INS(param) (void) param
+#define CMPERR_CHECK__DEL(param) 0
+#define CMPERR_CHECK__SPLIT(param) (void) param
+#define CMPERR_CHECK__VERIFY(param) /* nothing */
+#endif
+
+#define sub_left(a) (a)->sub[0]
+#define sub_right(a) (a)->sub[1]
+#define get_item(a) (a)->item
+
+/* RANK(a) = size of left subtree + 1 */
+
+#define rbal(a)\
+ (a)->rbal
+#define rzero(a)\
+ ( rbal(a) & ~3 )
+#define get_bal(a)\
+ ( rbal(a) & 3 )
+#define is_lskew(a)\
+ ( rbal(a) & 1 )
+#define is_rskew(a)\
+ ( rbal(a)>>1 & 1)
+#define set_lskew(a)\
+ ( rbal(a) |= 1 )
+#define set_rskew(a)\
+ ( rbal(a) |= 2 )
+#define set_skew(a,d)\
+ ( rbal(a) |= (1 << d) )
+#define unset_lskew(a)\
+ ( rbal(a) &= ~1 )
+#define unset_rskew(a)\
+ ( rbal(a) &= ~2 )
+#define get_rank(a)\
+ ( rbal(a) >> 2 )
+#define set_rank(a,r)\
+ ( rbal(a) = (r<<2 | get_bal(a)) )
+#define incr_rank(a,r)\
+ ( rbal(a) += r<<2 )
+#define decr_rank(a,r)\
+ ( rbal(a) -= r<<2 )
+
+#define AVL_MIN_DEPTH 0
+
+/*** Node management ***/
+
+#define DETACH_FUNC 1 /* nonzero to use function not macro */
+
+/* helper structure */
+typedef enum
+{
+ OP_BACKUP, OP_DETACH, OP_FREE
+}
+whichop_t;
+struct ptr_handler
+{
+ whichop_t whichop;
+ void *ptr;
+};
+
+#define ini_ptr_handler(h,op) struct ptr_handler h = { OP_##op, NULL }
+#define clear_node(a) \
+ sub_left(a) = NULL; \
+ sub_right(a) = NULL; \
+ (a)->up = NULL; \
+ rbal(a) = 4u
+
+/* Called by 'avl_ins', 'avl_dup', 'node_slice' */
+static avl_node *
+new_node (void *item, avl_node * up, avl_tree t)
+{
+ avl_node *a = (*t->alloc) (sizeof (avl_node));
+
+ if (a != NULL)
+ {
+ sub_left (a) = NULL;
+ sub_right (a) = NULL;
+ a->up = up;
+ a->rbal = 4u;
+ a->item = (*t->copy) (item);
+ }
+ return a;
+}
+
+static void
+free_node (avl_node * a, avl_tree t)
+{
+ a->item = (*t->dispose) (a->item);
+ (*t->dealloc) (a);
+}
+
+#define backup_item(backup,item,t) if (backup == NULL) ; else *backup = (*t->copy)(item)
+
+#if ! DETACH_FUNC
+
+/* macro to detach node [a] from tree [t] */
+#define detach_node(a,t,h) { struct ptr_handler *ch = h; \
+ clear_node(a); \
+ do { \
+ if (ch == NULL) ; \
+ else if (ch->whichop == OP_DETACH){ \
+ ch->ptr = a; \
+ break; \
+ } else if (ch->whichop == OP_BACKUP){ \
+ ch->ptr = (*t->copy)(a->item); \
+ } \
+ free_node(a, t); \
+ } while (0);} \
+ t->count--
+#else
+
+/* function to detach node [a] from tree [t] */
+static void
+detach_node (avl_node * a, avl_tree t, struct ptr_handler *h)
+{
+ clear_node (a);
+ do
+ {
+ if (h == NULL);
+ else if (h->whichop == OP_DETACH)
+ {
+ h->ptr = a;
+ break;
+ }
+ else if (h->whichop == OP_BACKUP)
+ {
+ h->ptr = (*t->copy) (a->item);
+ }
+ free_node (a, t);
+ }
+ while (0);
+ t->count--;
+}
+#endif /* DETACH_FUNC */
+
+/*** Tree methods ***/
+
+avl_tree
+avl_create (avl_compare_func compare, avl_item_copy_func copy,
+ avl_item_dispose_func dispose, avl_alloc_func alloc,
+ avl_dealloc_func dealloc, void *param)
+{
+ avl_tree t = (*alloc) (sizeof (struct avl_tree_));
+
+ if (t == NULL)
+ AVL_SHOW_ERROR ("%s\n", "couldn't create new handle in avl_create()");
+ else
+ {
+ t->root = NULL;
+ t->count = 0;
+ t->param = param;
+ t->compare = compare;
+ t->copy = copy;
+ t->dispose = dispose;
+ t->alloc = alloc;
+ t->dealloc = dealloc;
+ }
+ return t;
+}
+
+/* Empty the tree, using rotations */
+
+static void
+node_empty (avl_tree t)
+{
+ avl_node *a, *p;
+
+ for (a = t->root; a != NULL;)
+ {
+ p = a;
+ if (sub_right (a) == NULL)
+ a = sub_left (a);
+ else
+ {
+ while (sub_left (a) != NULL)
+ {
+ /* rotR(a) */
+ a = sub_left (a);
+ sub_left (p) = sub_right (a);
+ sub_right (a) = p;
+ p = a;
+ }
+ a = sub_right (p);
+ }
+ free_node (p, t);
+ t->count--;
+ }
+ t->root = NULL;
+}
+
+/* [t] is an existing tree handle */
+
+/* this function invokes node_empty() */
+
+void
+avl_reset (avl_tree t,
+ avl_compare_func compare,
+ avl_item_copy_func copy,
+ avl_item_dispose_func dispose,
+ avl_alloc_func alloc, avl_dealloc_func dealloc)
+{
+ if (t == NULL)
+ return;
+ node_empty (t);
+ t->compare = compare;
+ t->copy = copy;
+ t->dispose = dispose;
+ t->alloc = alloc;
+ t->dealloc = dealloc;
+}
+
+void
+avl_empty (avl_tree t)
+{
+ if (t != NULL)
+ node_empty (t);
+}
+
+/* Destroy nodes, free handle */
+
+void
+avl_destroy (avl_tree t)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL)
+ return;
+#endif
+ node_empty (t);
+ (*t->dealloc) (t);
+}
+
+avl_tree
+avl_dup (avl_tree t, void *param)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL)
+ return NULL;
+#endif
+ {
+ avl_tree tt = avl_create (
+ /*(avl_compare_func) */ t->compare,
+ /*(avl_item_copy_func) */ t->copy,
+ /*(avl_item_dispose_func) */ t->dispose,
+ /*(avl_alloc_func) */ t->alloc,
+ /*(avl_dealloc_func) */ t->dealloc,
+ param);
+
+ if (tt == NULL)
+ {
+ AVL_SHOW_ERROR ("%s\n", "couldn't create new handle in avl_dup()");
+ return NULL;
+ }
+
+ tt->count = t->count;
+
+ if (t->root == NULL)
+ return tt;
+
+ {
+ avl_node *a, *c, *s;
+
+ a = t->root;
+ tt->root = c = new_node (get_item (a), NULL, t);
+ if (c == NULL)
+ goto abort;
+
+ sub_right (c) = NULL; /*!!! */
+ rbal (c) = rbal (a);
+
+ while (1)
+ {
+ while (sub_left (a) != NULL)
+ {
+ a = sub_left (a);
+ sub_left (c) = s = new_node (get_item (a), NULL, t);
+ if (s == NULL)
+ goto recover;
+ s->up = c;
+ sub_right (s) = c;
+ c = s;
+ rbal (c) = rbal (a);
+ }
+
+ sub_left (c) = NULL;
+
+ while (sub_right (a) == NULL)
+ {
+ s = sub_right (c);
+ sub_right (c) = NULL;
+ c = s;
+ /* Find successor of [a] in original tree */
+ do
+ {
+ s = a;
+ a = s->up;
+ if (a == NULL)
+ return tt;
+ }
+ while (s != sub_left (a));
+ }
+
+ a = sub_right (a);
+ s = new_node (get_item (a), NULL, t);
+ if (s == NULL)
+ goto recover;
+ sub_right (s) = sub_right (c);
+ sub_right (c) = s;
+ s->up = c;
+ c = s;
+ rbal (c) = rbal (a);
+ }
+ /* recovery code */
+ recover:
+ while (1)
+ {
+ s = sub_right (c);
+ sub_right (c) = NULL;
+ if (s == NULL)
+ break;
+ c = s;
+ }
+ node_empty (tt);
+
+ abort:
+ (*t->dealloc) (tt);
+ AVL_SHOW_ERROR ("%s\n", "couldn't allocate node in avl_dup()");
+ return NULL;
+ }
+ }
+}
+
+avl_bool_t
+avl_isempty (avl_tree t)
+{
+#ifndef AVL_NULLCHECKS
+ return t == NULL || t->root == NULL;
+#else
+ return t->root == NULL;
+#endif
+}
+
+avl_size_t
+avl_size (avl_tree t)
+{
+#ifndef AVL_NULLCHECKS
+ return t == NULL ? 0 : t->count;
+#else
+ return t->count;
+#endif
+}
+
+static int
+depth (avl_node * a)
+{
+ int h = AVL_MIN_DEPTH;
+
+ for (; a != NULL; ++h)
+ a = a->sub[is_rskew (a)];
+ return h;
+}
+
+static avl_node *
+node_first (avl_node * a)
+{
+ while (sub_left (a) != NULL)
+ a = sub_left (a);
+ return a;
+}
+
+static avl_node *
+node_last (avl_node * a)
+{
+ while (sub_right (a) != NULL)
+ a = sub_right (a);
+ return a;
+}
+
+/* [a] : non-null */
+
+static avl_node *
+node_next (avl_node * a)
+{
+ if (sub_right (a) != NULL)
+ return node_first (sub_right (a));
+ {
+ avl_node *p;
+
+ do
+ {
+ p = a;
+ a = p->up;
+ }
+ while (a != NULL && sub_right (a) == p);
+ return a;
+ }
+}
+
+/* [a] : non-null */
+
+static avl_node *
+node_prev (avl_node * a)
+{
+ if (sub_left (a) != NULL)
+ return node_last (sub_left (a));
+ {
+ avl_node *p;
+
+ do
+ {
+ p = a;
+ a = p->up;
+ }
+ while (a != NULL && sub_left (a) == p);
+ return a;
+ }
+}
+
+static avl_node *
+node_find (const void *item, avl_tree t)
+{
+ avl_node *a = t->root;
+ avl_compare_func cmp = t->compare;
+ int c;
+
+ while (a != NULL)
+ {
+ c = Item_Compare (cmp, t, item, get_item (a));
+ CMPERR_CHECK__FIND (t->param);
+ if (c < 0)
+ a = a->sub[0];
+ else if (c)
+ a = a->sub[1];
+ else
+ break;
+ }
+ return a;
+}
+
+#if 0==1
+static avl_node **
+avl_search (const void *item, avl_tree t, int *dir)
+{
+ if (t->root == NULL)
+ return &t->root;
+ {
+ avl_node **r = &t->root;
+ avl_node *a = *r;
+ avl_compare_func cmp = t->compare;
+ int c;
+
+ while (1)
+ {
+ c = Item_Compare (cmp, t, item, get_item (a));
+ if (!c)
+ break;
+ r = &a->sub[c = c > 0];
+ if (*r == NULL)
+ {
+ *dir = c;
+ break;
+ }
+ a = *r;
+ }
+
+ return r;
+ }
+}
+#endif
+
+static avl_size_t
+get_index (avl_node * a)
+{
+ avl_size_t n = get_rank (a);
+ avl_node *p;
+
+ while ((p = a->up) != NULL)
+ {
+ if (a != sub_left (p))
+ n += get_rank (p);
+ a = p;
+ }
+ return n;
+}
+
+/* Find item by index */
+
+static avl_node *
+node_find_index (avl_size_t idx, avl_tree t)
+{
+ avl_node *a = t->root;
+ int c;
+
+ if (idx == 0 || idx > t->count)
+ return NULL;
+ if (idx == 1)
+ return node_first (a);
+ if (idx == t->count)
+ return node_last (a);
+
+ while ((c = idx - get_rank (a)) != 0)
+ {
+ if (c < 0)
+ a = sub_left (a);
+ else
+ {
+ idx = c;
+ a = sub_right (a);
+ }
+ }
+
+ return a;
+}
+
+/* Rebalance starting from node [a] where a->sub[d_]
+ * is deeper post-insertion
+ */
+
+static avl_code_t
+rebalance_ins (avl_node * a, int dir, avl_tree t)
+{
+ if (a != NULL)
+ {
+ avl_node *p;
+
+ while (1)
+ {
+ incr_rank (a, !dir);
+ if (get_bal (a))
+ break;
+ set_skew (a, dir);
+ p = a->up;
+ if (p == NULL)
+ return 2;
+ dir = a != sub_left (p);
+ a = p;
+ }
+
+ /* Now bal(a) == -1 or +1 */
+ /* Rotate if need be */
+
+ if (0 == dir)
+ {
+ if (is_rskew (a))
+ unset_rskew (a);
+
+ else
+ {
+ avl_node *u = a->up;
+ avl_node **r =
+ u != NULL ? &u->sub[a != sub_left (u)] : &t->root;
+
+ p = a;
+
+ if (is_lskew (sub_left (p)))
+ {
+ /* rotR(p) */
+ a = sub_left (p);
+ sub_left (p) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = p;
+ sub_right (a) = p;
+ unset_lskew (p);
+ rbal (p) -= rzero (a);
+ }
+ else
+ {
+ /* rotLR(p) */
+ a = sub_right (sub_left (p));
+ sub_right (sub_left (p)) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = sub_left (p);
+ sub_left (p)->up = a;
+ sub_left (a) = sub_left (p);
+ sub_left (p) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = p;
+ sub_right (a) = p;
+ switch (get_bal (a))
+ {
+ case 0: /* not skewed */
+ unset_lskew (p);
+ unset_rskew (sub_left (a));
+ break;
+ case 1: /* left skew */
+ unset_lskew (p);
+ set_rskew (p);
+ unset_rskew (sub_left (a));
+ break;
+ case 2: /* right skew */
+ unset_lskew (p);
+ unset_rskew (sub_left (a));
+ set_lskew (sub_left (a));
+ } /* switch */
+ rbal (a) += rzero (sub_left (a));
+ rbal (p) -= rzero (a);
+ } /* which rot */
+ rbal (a) &= ~3;
+ a->up = u;
+ p->up = a;
+ *r = a;
+ } /* rot or no rot ? */
+ }
+ else
+ {
+ /* direction == 1 */
+
+ if (is_lskew (a))
+ unset_lskew (a);
+
+ else
+ {
+ avl_node *u = a->up;
+ avl_node **r =
+ u != NULL ? &u->sub[a != sub_left (u)] : &t->root;
+
+ p = a;
+ if (is_rskew (sub_right (p)))
+ {
+ /* rotL(p) */
+ a = sub_right (p);
+ sub_right (p) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = p;
+ sub_left (a) = p;
+ unset_rskew (p);
+ rbal (a) += rzero (p);
+ }
+ else
+ {
+ /* rotRL(p) */
+ a = sub_left (sub_right (p));
+ sub_left (sub_right (p)) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = sub_right (p);
+ sub_right (p)->up = a;
+ sub_right (a) = sub_right (p);
+ sub_right (p) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = p;
+ sub_left (a) = p;
+ switch (get_bal (a))
+ {
+ case 0: /* not skewed */
+ unset_rskew (p);
+ unset_lskew (sub_right (a));
+ break;
+ case 1: /* left skew */
+ unset_rskew (p);
+ unset_lskew (sub_right (a));
+ set_rskew (sub_right (a));
+ break;
+ case 2: /* right skew */
+ unset_rskew (p);
+ set_lskew (p);
+ unset_lskew (sub_right (a));
+ } /* switch */
+ rbal (sub_right (a)) -= rzero (a);
+ rbal (a) += rzero (p);
+
+ } /* which rot */
+
+ rbal (a) &= ~3;
+ a->up = u;
+ p->up = a;
+ *r = a;
+ } /* rot or not rot ? */
+ } /* if 0==dir */
+
+ /* The tree rooted at 'a' is now valid */
+ /* Finish adjusting ranks */
+
+ while ((p = a->up) != NULL)
+ {
+ incr_rank (p, (a == sub_left (p)));
+ a = p;
+ }
+
+ return 1;
+
+ } /* if a != 0 */
+ return 2;
+}
+
+/* detach [p] : non-null */
+
+/* only the linkage is tweaked */
+
+static avl_code_t
+rebalance_del (avl_node * p, avl_tree t, void **backup)
+{
+ avl_node **r, *a, *c;
+ int dir, bal;
+
+ a = p->up;
+ if (a == NULL)
+ r = &t->root;
+ else
+ r = &a->sub[dir = p != sub_left (a)];
+
+ c = sub_right (p);
+ if (c == NULL && sub_left (p) == NULL)
+ *r = NULL;
+ else if (c == NULL || sub_left (p) == NULL)
+ {
+ *r = c != NULL ? c : sub_left (p);
+ (*r)->up = a;
+ }
+ else
+ {
+ if (sub_left (c) == NULL)
+ {
+ a = c;
+ dir = 1;
+ }
+ else
+ {
+ do
+ c = sub_left (c);
+ while (sub_left (c) != NULL);
+ a = c->up;
+ dir = 0;
+ sub_left (a) = sub_right (c);
+ if (sub_right (c) != NULL)
+ sub_right (c)->up = a;
+ sub_right (c) = sub_right (p);
+ sub_right (c)->up = c;
+ }
+ sub_left (c) = sub_left (p);
+ sub_left (c)->up = c;
+ c->up = p->up;
+ rbal (c) = rbal (p);
+ *r = c;
+ }
+
+ backup_item (backup, p->item, t);
+ detach_node (p, t, NULL);
+
+ /* Start backtracking : subtree of [a] in direction [dir] is less deep */
+
+ for (;; a = (*r)->up)
+ {
+ if (a == NULL)
+ return 2;
+
+ decr_rank (a, !dir);
+ bal = get_bal (a);
+
+ if (0 == dir)
+ {
+ if (bal == 0)
+ {
+ set_rskew (a);
+ break;
+ }
+ if (a->up == NULL)
+ r = &t->root;
+ else
+ {
+ dir = a != sub_left (a->up);
+ r = &a->up->sub[dir];
+ }
+ if (bal & 1)
+ unset_lskew (a);
+ if (get_bal (a))
+ {
+ p = a;
+ bal = get_bal (sub_right (p));
+ if (!(bal & 1))
+ {
+ /* bal = 0 or +1 */
+ /* rotL(p) */
+ a = sub_right (p);
+ sub_right (p) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = p;
+ sub_left (a) = p;
+ if (bal)
+ {
+ unset_rskew (p);
+ unset_rskew (a);
+ }
+ else
+ set_lskew (a);
+ rbal (a) += rzero (p);
+ }
+ else
+ {
+ /* rotRL(p) */
+ a = sub_left (sub_right (p));
+ sub_left (sub_right (p)) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = sub_right (p);
+ sub_right (p)->up = a;
+ sub_right (a) = sub_right (p);
+ sub_right (p) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = p;
+ sub_left (a) = p;
+ switch (get_bal (a))
+ {
+ case 0: /* not skewed */
+ unset_rskew (p);
+ unset_lskew (sub_right (a));
+ break;
+ case 1: /* left skew */
+ unset_rskew (p);
+ unset_lskew (sub_right (a));
+ set_rskew (sub_right (a));
+ break;
+ case 2: /* right skew */
+ unset_rskew (p);
+ set_lskew (p);
+ unset_lskew (sub_right (a));
+ } /* switch */
+ rbal (a) &= ~3;
+ rbal (sub_right (a)) -= rzero (a);
+ rbal (a) += rzero (p);
+
+ } /* which rot */
+
+ a->up = p->up;
+ p->up = a;
+ /* Done with rotation */
+ *r = a;
+ if (bal == 0)
+ break;
+ } /* if getbal(a) */
+ }
+ else
+ {
+ /* dir == 1 */
+
+ if (bal == 0)
+ {
+ set_lskew (a);
+ break;
+ }
+ if (a->up == NULL)
+ r = &t->root;
+ else
+ {
+ dir = a != sub_left (a->up);
+ r = &a->up->sub[dir];
+ }
+ if (bal & 2)
+ unset_rskew (a);
+ if (get_bal (a))
+ {
+ p = a;
+ bal = get_bal (sub_left (p));
+ if (!(bal & 2))
+ {
+ /* bal = 0 or -1 */
+ /* rotR(p) */
+ a = sub_left (p);
+ sub_left (p) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = p;
+ sub_right (a) = p;
+ if (bal)
+ {
+ unset_lskew (p);
+ unset_lskew (a);
+ }
+ else
+ set_rskew (a);
+ rbal (p) -= rzero (a);
+ }
+ else
+ {
+ /* rotLR(p) */
+ a = sub_right (sub_left (p));
+ sub_right (sub_left (p)) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = sub_left (p);
+ sub_left (p)->up = a;
+ sub_left (a) = sub_left (p);
+ sub_left (p) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = p;
+ sub_right (a) = p;
+ switch (get_bal (a))
+ {
+ case 0: /* not skewed */
+ unset_lskew (p);
+ unset_rskew (sub_left (a));
+ break;
+ case 1: /* left skew */
+ unset_lskew (p);
+ set_rskew (p);
+ unset_rskew (sub_left (a));
+ break;
+ case 2: /* right skew */
+ unset_lskew (p);
+ unset_rskew (sub_left (a));
+ set_lskew (sub_left (a));
+ } /* switch */
+ rbal (a) &= ~3;
+ rbal (a) += rzero (sub_left (a));
+ rbal (p) -= rzero (a);
+ } /* which rot */
+
+ a->up = p->up;
+ p->up = a;
+ /* Done with rotation */
+ *r = a;
+ if (bal == 0)
+ break;
+ } /* if getbal(a) */
+ } /* if dir==0 else 1 */
+ } /* for */
+
+ /* Finish adjusting ranks */
+ while ((p = a->up) != NULL)
+ {
+ decr_rank (p, (a == sub_left (p)));
+ a = p;
+ }
+
+ return 1;
+}
+
+void *
+avl_first (avl_tree t)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif
+ return NULL;
+ return get_item (node_first (t->root));
+}
+
+void *
+avl_last (avl_tree t)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif
+ return NULL;
+ return get_item (node_last (t->root));
+}
+
+void *
+avl_find (const void *item, avl_tree t)
+{
+ avl_node *a;
+
+#ifndef AVL_NULLCHECKS
+ if (t == NULL)
+ return NULL;
+#endif
+ a = node_find (item, t);
+ return a != NULL ? get_item (a) : NULL;
+}
+
+/*
+ * Return smallest index i in [1:len] s.t. tree[i] matches [item],
+ * or zero if not found
+ */
+
+avl_size_t
+avl_index (const void *item, avl_tree t)
+{
+#ifndef AVL_NULLCHECKS
+ if (item == NULL || t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif
+ return 0;
+
+ {
+ avl_compare_func cmp = t->compare;
+ avl_node *a, *p;
+ avl_size_t idx = 0, n = 0;
+ int c;
+
+ for (a = t->root;;)
+ {
+ c = Item_Compare (cmp, t, item, get_item (a));
+ CMPERR_CHECK__INDEX (t->param);
+ if (!c)
+ idx = n + get_rank (a);
+ else if (c > 0)
+ n += get_rank (a);
+ p = a->sub[c > 0];
+ if (p == NULL)
+ return idx;
+ a = p;
+ }
+ }
+}
+
+/* (lo,hi) where
+ * lo smallest index s.t. t[lo] >= lo_item, or t->count+1 and
+ * hi greatest index s.t. t[hi] <= hi_item, or 0
+ */
+avl_code_t
+avl_span (const void *lo_item,
+ const void *hi_item,
+ avl_tree t, avl_size_t * lo_idx, avl_size_t * hi_idx)
+{
+ *lo_idx = t->count + 1;
+ *hi_idx = 0;
+
+#ifndef AVL_NULLCHECKS
+ if (t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif
+ return -1;
+
+ {
+ avl_compare_func cmp = t->compare;
+ avl_node *a;
+ avl_size_t n = 0;
+ int c;
+
+ c = Item_Compare (cmp, t, lo_item, hi_item) > 0;
+ CMPERR_CHECK__SPAN (t->param);
+ if (c > 0)
+ {
+ const void *temp = lo_item;
+
+ lo_item = hi_item;
+ hi_item = temp;
+ }
+
+ a = t->root;
+ do
+ {
+ c = Item_Compare (cmp, t, lo_item, get_item (a));
+ CMPERR_CHECK__SPAN (t->param);
+ if (c > 0)
+ {
+ n += get_rank (a);
+ a = sub_right (a);
+ }
+ else
+ {
+ *lo_idx = n + get_rank (a);
+ a = sub_left (a);
+ }
+ }
+ while (a);
+
+ a = t->root;
+ do
+ {
+ c = Item_Compare (cmp, t, hi_item, get_item (a));
+ CMPERR_CHECK__SPAN (t->param);
+ if (c < 0)
+ {
+ a = sub_left (a);
+ }
+ else
+ {
+ *hi_idx += get_rank (a);
+ a = sub_right (a);
+ }
+ }
+ while (a);
+ return 0;
+ }
+}
+
+/*
+ * Find the smallest item in tree [t] that is GEQ the passed item
+ */
+
+void *
+avl_find_atleast (const void *item, avl_tree t)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif
+ return NULL;
+ {
+ avl_compare_func cmp = t->compare;
+ avl_node *a = t->root;
+ void *p = NULL;
+ int c;
+
+ do
+ {
+ c = Item_Compare (cmp, t, item, get_item (a));
+ CMPERR_CHECK__FIND (t->param);
+ if (c > 0)
+ {
+ a = sub_right (a);
+ }
+ else
+ {
+ p = get_item (a);
+ a = sub_left (a);
+ }
+ }
+ while (a);
+ return p;
+ }
+}
+
+/*
+ * Find the greatest item in tree [t] that is LEQ the passed item
+ */
+
+void *
+avl_find_atmost (const void *item, avl_tree t)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif
+ return NULL;
+ {
+ avl_compare_func cmp = t->compare;
+ avl_node *a = t->root;
+ void *p = NULL;
+ int c;
+
+ do
+ {
+ c = Item_Compare (cmp, t, item, get_item (a));
+ CMPERR_CHECK__FIND (t->param);
+ if (c < 0)
+ {
+ a = sub_left (a);
+ }
+ else
+ {
+ p = get_item (a);
+ a = sub_right (a);
+ }
+ }
+ while (a);
+ return p;
+ }
+}
+
+/* Retrieve item of index [idx] in tree [t] */
+
+void *
+avl_find_index (avl_size_t idx, avl_tree t)
+{
+ avl_node *a;
+
+#ifndef AVL_NULLCHECKS
+ if (t == NULL)
+ return NULL;
+#endif
+ a = node_find_index (idx, t);
+ return a != NULL ? get_item (a) : NULL;
+}
+
+#define attach_node(ptr,up,t)\
+ ptr = new_node(item, up, t);\
+ if (ptr == NULL){\
+ AVL_SHOW_ERROR("%s\n", "couldn't allocate node");\
+ return -1;\
+ }\
+ t->count++
+
+/* Iterative insertion */
+
+avl_code_t
+avl_ins (void *item, avl_tree t, avl_bool_t allow_duplicates)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL)
+ return NULL;
+ {
+#endif
+ avl_compare_func cmp = t->compare;
+ avl_node **r, *a;
+ int dir;
+
+ for (r = &t->root, a = NULL; *r != NULL; r = &a->sub[dir = dir > 0])
+ {
+ a = *r;
+ dir = Item_Compare (cmp, t, item, get_item (a));
+ CMPERR_CHECK__INS (t->param);
+ if (!dir && !allow_duplicates)
+ return 0;
+ }
+
+ attach_node (*r, a, t);
+
+ return rebalance_ins (a, dir, t);
+
+#ifndef AVL_NULLCHECKS
+ } /* end if non-empty tree */
+#endif
+}
+
+avl_code_t
+avl_del (void *item, avl_tree t, void **backup)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif
+ return 0;
+ {
+ avl_node *a = node_find (item, t);
+
+ if (a == NULL)
+ return CMPERR_CHECK__DEL (t->param);
+ return rebalance_del (a, t, backup);
+ }
+}
+
+/* helper function */
+static avl_code_t
+node_del_first (avl_tree t, struct ptr_handler *h)
+{
+ avl_node *p, *a, *c;
+ int bal;
+
+ p = node_first (t->root);
+ a = p->up;
+ if (sub_right (p) != NULL)
+ sub_right (p)->up = a;
+ if (a == NULL)
+ t->root = sub_right (p);
+ else
+ sub_left (a) = sub_right (p);
+
+ detach_node (p, t, h);
+
+ /* Start backtracking : subtree of [a] in direction [0] is less deep */
+
+ for (;; a = c)
+ {
+ if (a == NULL)
+ return 2;
+
+ decr_rank (a, 1);
+ bal = get_bal (a);
+
+ if (bal == 0)
+ {
+ set_rskew (a);
+ break;
+ }
+ if (bal & 1)
+ unset_lskew (a);
+ c = a->up;
+ if (get_bal (a))
+ {
+ p = a;
+ bal = get_bal (sub_right (p));
+ if (!(bal & 1))
+ {
+ /* bal = 0 or +1 */
+ /* rotL(p) */
+ a = sub_right (p);
+ sub_right (p) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = p;
+ sub_left (a) = p;
+ if (bal)
+ {
+ unset_rskew (p);
+ unset_rskew (a);
+ }
+ else
+ set_lskew (a);
+ rbal (a) += rzero (p);
+ }
+ else
+ {
+ /* rotRL(p) */
+ a = sub_left (sub_right (p));
+ sub_left (sub_right (p)) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = sub_right (p);
+ sub_right (p)->up = a;
+ sub_right (a) = sub_right (p);
+ sub_right (p) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = p;
+ sub_left (a) = p;
+ switch (get_bal (a))
+ {
+ case 0: /* not skewed */
+ unset_rskew (p);
+ unset_lskew (sub_right (a));
+ break;
+ case 1: /* left skew */
+ unset_rskew (p);
+ unset_lskew (sub_right (a));
+ set_rskew (sub_right (a));
+ break;
+ case 2: /* right skew */
+ unset_rskew (p);
+ set_lskew (p);
+ unset_lskew (sub_right (a));
+ } /* switch */
+ rbal (a) &= ~3;
+ rbal (sub_right (a)) -= rzero (a);
+ rbal (a) += rzero (p);
+ } /* which rot */
+
+ a->up = p->up;
+ p->up = a;
+ /* Done with rotation */
+ if (c != NULL)
+ sub_left (c) = a;
+ else
+ t->root = a;
+ if (bal == 0)
+ break;
+ } /* if getbal(a) */
+ } /* for */
+
+ /* Finish adjusting ranks */
+ while ((a = a->up) != NULL)
+ {
+ decr_rank (a, 1);
+ }
+
+ return 1;
+}
+
+/* helper function */
+static avl_code_t
+node_del_last (avl_tree t, struct ptr_handler *h)
+{
+
+ avl_node *p, *a, *c;
+ int bal;
+
+ p = node_last (t->root);
+ a = p->up;
+ if (sub_left (p) != NULL)
+ sub_left (p)->up = a;
+ if (a == NULL)
+ t->root = sub_left (p);
+ else
+ sub_right (a) = sub_left (p);
+
+ detach_node (p, t, h);
+
+ /* Start backtracking : subtree of [a] in direction [1] is less deep */
+
+ for (;; a = c)
+ {
+ if (a == NULL)
+ return 2;
+
+ bal = get_bal (a);
+ if (bal == 0)
+ {
+ set_lskew (a);
+ break;
+ }
+ if (bal & 2)
+ unset_rskew (a);
+ c = a->up;
+ if (get_bal (a))
+ {
+ p = a;
+ bal = get_bal (sub_left (p));
+ if (!(bal & 2))
+ {
+ /* bal = 0 or -1 */
+ /* rotR(p) */
+ a = sub_left (p);
+ sub_left (p) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = p;
+ sub_right (a) = p;
+ if (bal)
+ {
+ unset_lskew (p);
+ unset_lskew (a);
+ }
+ else
+ set_rskew (a);
+ rbal (p) -= rzero (a);
+ }
+ else
+ {
+ /* rotLR(p) */
+ a = sub_right (sub_left (p));
+ sub_right (sub_left (p)) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = sub_left (p);
+ sub_left (p)->up = a;
+ sub_left (a) = sub_left (p);
+ sub_left (p) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = p;
+ sub_right (a) = p;
+ switch (get_bal (a))
+ {
+ case 0: /* not skewed */
+ unset_lskew (p);
+ unset_rskew (sub_left (a));
+ break;
+ case 1: /* left skew */
+ unset_lskew (p);
+ set_rskew (p);
+ unset_rskew (sub_left (a));
+ break;
+ case 2: /* right skew */
+ unset_lskew (p);
+ unset_rskew (sub_left (a));
+ set_lskew (sub_left (a));
+ } /* switch */
+ rbal (a) &= ~3;
+ rbal (a) += rzero (sub_left (a));
+ rbal (p) -= rzero (a);
+ } /* which rot */
+
+ a->up = p->up;
+ p->up = a;
+ /* Done with rotation */
+ if (c != NULL)
+ sub_right (c) = a;
+ else
+ t->root = a;
+ if (bal == 0)
+ break;
+ } /* if getbal(a) */
+ } /* for */
+
+ return 1;
+}
+
+/* [p] : juncture node (zeroed out) */
+
+/* [n] : rank of [p] in resulting tree */
+
+/* [delta] = depth_1 - depth_0 */
+
+static avl_code_t
+join_left (avl_node * p, avl_node ** r0, avl_node * r1, int delta, int n)
+{
+ avl_node *a = NULL, **r = r0;
+
+ if (r1 == NULL)
+ {
+ while (*r != NULL)
+ {
+ a = *r;
+ n -= get_rank (a);
+ r = &sub_right (a);
+ }
+ }
+ else
+ {
+ while (delta < -1)
+ {
+ a = *r;
+ delta += is_lskew (a) + 1;
+ n -= get_rank (a);
+ r = &sub_right (a);
+ }
+ r1->up = p;
+ if (*r != NULL)
+ (*r)->up = p;
+ if (delta)
+ set_lskew (p);
+ }
+
+ /* at this point bal(*r) = -1 or 0 */
+ sub_left (p) = *r;
+ sub_right (p) = r1;
+ p->up = a;
+ set_rank (p, n);
+ *r = p;
+
+ for (;;)
+ {
+ if (a == NULL)
+ return 2;
+ if (get_bal (a))
+ break;
+ set_rskew (a);
+ a = a->up;
+ }
+
+ /* Rotate if need be */
+ /* No (+2,0) rotation to do */
+
+ if (is_lskew (a))
+ unset_lskew (a);
+
+ else
+ {
+ avl_node *p = a;
+
+ if (is_rskew (sub_right (p)))
+ {
+ /* rotL(p) */
+ a = sub_right (p);
+ sub_right (p) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = p;
+ sub_left (a) = p;
+ unset_rskew (p);
+ rbal (a) += rzero (p);
+ }
+ else
+ {
+ /* rotRL(p) */
+ a = sub_left (sub_right (p));
+ sub_left (sub_right (p)) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = sub_right (p);
+ sub_right (p)->up = a;
+ sub_right (a) = sub_right (p);
+ sub_right (p) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = p;
+ sub_left (a) = p;
+ switch (get_bal (a))
+ {
+ case 0: /* not skewed */
+ unset_rskew (p);
+ unset_lskew (sub_right (a));
+ break;
+ case 1: /* left skew */
+ unset_rskew (p);
+ unset_lskew (sub_right (a));
+ set_rskew (sub_right (a));
+ break;
+ case 2: /* right skew */
+ unset_rskew (p);
+ set_lskew (p);
+ unset_lskew (sub_right (a));
+ } /* switch */
+ rbal (sub_right (a)) -= rzero (a);
+ rbal (a) += rzero (p);
+ } /* which rot */
+
+ rbal (a) &= ~3;
+ a->up = p->up;
+ p->up = a;
+ if (a->up != NULL)
+ sub_right (a->up) = a;
+ else
+ *r0 = a;
+ } /* rot or not rot */
+
+ return 1;
+}
+
+/* [p] : juncture node */
+
+/* [n] : rank of [p] in resulting tree */
+
+static avl_code_t
+join_right (avl_node * p, avl_node * r0, avl_node ** r1, int delta, int n)
+{
+ avl_node *a = NULL, **r = r1;
+
+ if (r0 == NULL)
+ {
+ while (*r != NULL)
+ {
+ a = *r;
+ incr_rank (a, n);
+ r = &sub_left (a);
+ }
+ n = 1;
+ }
+ else
+ {
+ while (delta > +1)
+ {
+ a = *r;
+ delta -= is_rskew (a) + 1;
+ incr_rank (a, n);
+ r = &sub_left (a);
+ }
+ r0->up = p;
+ if (*r != NULL)
+ (*r)->up = p;
+ if (delta)
+ set_rskew (p);
+ }
+
+ /* at this point bal(*r) = +1 or 0 */
+ sub_left (p) = r0;
+ sub_right (p) = *r;
+ set_rank (p, n);
+ p->up = a;
+ *r = p;
+
+ for (;;)
+ {
+ if (a == NULL)
+ return 2;
+ if (get_bal (a))
+ break;
+ set_lskew (a);
+ a = a->up;
+ }
+
+ /* Rotate if need be */
+ /* No (-2,0) rotation to do */
+
+ if (is_rskew (a))
+ unset_rskew (a);
+
+ else
+ {
+ avl_node *p = a;
+
+ if (is_lskew (sub_left (p)))
+ {
+ /* rotR(p) */
+ a = sub_left (p);
+ sub_left (p) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = p;
+ sub_right (a) = p;
+ unset_lskew (p);
+ rbal (p) -= rzero (a);
+ }
+ else
+ {
+ /* rotLR(p) */
+ a = sub_right (sub_left (p));
+ sub_right (sub_left (p)) = sub_left (a);
+ if (sub_left (a) != NULL)
+ sub_left (a)->up = sub_left (p);
+ sub_left (p)->up = a;
+ sub_left (a) = sub_left (p);
+ sub_left (p) = sub_right (a);
+ if (sub_right (a) != NULL)
+ sub_right (a)->up = p;
+ sub_right (a) = p;
+ switch (get_bal (a))
+ {
+ case 0: /* not skewed */
+ unset_lskew (p);
+ unset_rskew (sub_left (a));
+ break;
+ case 1: /* left skew */
+ unset_lskew (p);
+ set_rskew (p);
+ unset_rskew (sub_left (a));
+ break;
+ case 2: /* right skew */
+ unset_lskew (p);
+ unset_rskew (sub_left (a));
+ set_lskew (sub_left (a));
+ } /* end switch */
+ rbal (a) += rzero (sub_left (a));
+ rbal (p) -= rzero (a);
+ } /* end which rot */
+
+ rbal (a) &= ~3;
+ a->up = p->up;
+ p->up = a;
+ if (a->up != NULL)
+ sub_left (a->up) = a;
+ else
+ *r1 = a;
+ } /* end rot or not rot */
+
+ return 1;
+}
+
+avl_code_t
+avl_del_first (avl_tree t, void **backup)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif
+ return 0;
+ {
+ avl_code_t rv;
+
+ if (backup == NULL)
+ {
+ rv = node_del_first (t, NULL);
+ }
+ else
+ {
+ ini_ptr_handler (h, BACKUP);
+ rv = node_del_first (t, &h);
+ *backup = h.ptr;
+ }
+ return rv;
+ }
+}
+
+avl_code_t
+avl_del_last (avl_tree t, void **backup)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif
+ return 0;
+ {
+ avl_code_t rv;
+
+ if (backup == NULL)
+ {
+ rv = node_del_last (t, NULL);
+ }
+ else
+ {
+ ini_ptr_handler (h, BACKUP);
+ rv = node_del_last (t, &h);
+ *backup = h.ptr;
+ }
+ return rv;
+ }
+}
+
+avl_code_t
+avl_ins_index (void *item, avl_size_t idx, avl_tree t)
+{
+ avl_node *p;
+
+ if (idx == 0 || t == NULL || idx > t->count + 1)
+ return 0;
+
+ attach_node (p, NULL, t);
+ /* Note: 'attach_node' macro increments t->count */
+
+ if (idx == 1)
+ {
+ return join_right (p, (avl_node *) NULL, &t->root, /*delta= */ 0, 1);
+ }
+ else if (idx == t->count)
+ {
+ return
+ join_left (p, &t->root, (avl_node *) NULL, /*delta= */ 0, t->count);
+ }
+ else
+ {
+ avl_node *a = node_find_index (idx - 1, t);
+ int dir;
+
+ if (sub_right (a) != NULL)
+ {
+ a = node_first (sub_right (a));
+ sub_left (a) = p;
+ dir = 0;
+ }
+ else
+ {
+ sub_right (a) = p;
+ dir = 1;
+ }
+
+ p->up = a;
+ return rebalance_ins (a, dir, t);
+ }
+}
+
+avl_code_t
+avl_del_index (avl_size_t idx, avl_tree t, void **backup)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL)
+ return 0;
+#endif
+
+ if (idx == 0 || idx > t->count)
+ return 0;
+ if (idx == 1)
+ return avl_del_first (t, backup);
+ if (idx == t->count)
+ return avl_del_last (t, backup);
+ {
+ avl_node *a = node_find_index (idx, t);
+
+ return rebalance_del (a, t, backup);
+ }
+}
+
+/*
+ * Outcome: [t0] handles the concatenation of [t0] and [t1]
+ */
+
+void
+avl_cat (avl_tree t0, avl_tree t1)
+{
+#ifndef AVL_NULLCHECKS
+ if (t0 == NULL || t1 == NULL || t1->root == NULL)
+#else
+ if (t1->root == NULL)
+#endif
+ return;
+
+ if (t0->root == NULL)
+ {
+ t0->root = t1->root;
+ t0->count = t1->count;
+ t1->root = NULL;
+ t1->count = 0;
+
+ }
+ else
+ {
+ int delta = depth (t1->root) - depth (t0->root);
+
+ ini_ptr_handler (h, DETACH);
+
+ if (delta <= 0)
+ {
+ if (node_del_first (t1, &h) == 2)
+ --delta;
+ (void) join_left ((avl_node *) h.ptr, &t0->root, t1->root, delta,
+ t0->count + 1);
+ }
+ else
+ {
+ if (node_del_last (t0, &h) == 2)
+ ++delta;
+ (void) join_right ((avl_node *) h.ptr, t0->root, &t1->root, delta,
+ t0->count + 1);
+ t0->root = t1->root;
+ }
+
+ t1->root = NULL;
+ t0->count += t1->count + 1;
+ t1->count = 0;
+ }
+}
+
+/*
+ * - [t0] and [t1] are existing handles
+ * - See Donald Knuth, TAOCP Vol.3 "Sorting and searching"
+ */
+
+avl_code_t
+avl_split (const void *item, avl_tree t, avl_tree t0, avl_tree t1)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif /* AVL_NULLCHECKS */
+ return 0;
+
+ t0->root = NULL;
+ t1->root = NULL;
+ t0->count = 0;
+ t1->count = 0;
+
+ {
+ avl_compare_func cmp = t->compare;
+ avl_node *a, *p, *sn; /* sn: split node */
+ int d_, k, na, an[AVL_STACK_CAPACITY];
+
+ /* invariant: [na]= size of tree rooted at [a] plus one */
+
+ for (a = t->root, na = t->count + 1, k = 0;;)
+ {
+ d_ = Item_Compare (cmp, t, item, get_item (a));
+ CMPERR_CHECK__SPLIT (t->param);
+ if (!d_)
+ break;
+ p = a->sub[d_ = d_ > 0];
+ if (p == NULL)
+ return 0;
+ an[k++] = na;
+ if (d_)
+ na -= get_rank (a);
+ else
+ na = get_rank (a);
+ a = p;
+ }
+
+ /* record split node */
+ sn = a;
+
+ if (k == 0)
+ {
+ t0->root = sub_left (a);
+ t1->root = sub_right (a);
+ if (t0->root != NULL)
+ t0->root->up = NULL;
+ if (t1->root != NULL)
+ t1->root->up = NULL;
+ t0->count = get_rank (a) - 1;
+ t1->count = t->count - get_rank (a);
+ }
+ else
+ {
+ avl_node *r[2], *rr;
+ int h[2], ha, hh;
+ avl_size_t n[2], nn;
+
+ r[0] = sub_left (a);
+ r[1] = sub_right (a);
+ if (r[0] != NULL)
+ r[0]->up = NULL;
+ if (r[1] != NULL)
+ r[1]->up = NULL;
+ ha = depth (a);
+ h[0] = ha - (is_rskew (a) ? 2 : 1);
+ h[1] = ha - (is_lskew (a) ? 2 : 1);
+ n[0] = get_rank (a); /* size of r[0] plus one */
+ n[1] = na - n[0]; /* size of r[1] plus one */
+
+ for (p = a->up, d_ = a != sub_left (p);;)
+ {
+
+ a = p; /* a: juncture node */
+ p = a->up;
+
+ if (d_ == 0)
+ {
+ hh = h[1];
+ ha += (is_rskew (a) ? 2 : 1);
+ h[1] = ha - (is_lskew (a) ? 2 : 1);
+ nn = n[1];
+ n[1] += an[k - 1] - get_rank (a);
+ if (p != NULL)
+ d_ = a != sub_left (p);
+ rbal (a) = 0;
+
+ if (h[1] >= hh)
+ {
+ rr = r[1];
+ r[1] = sub_right (a);
+ if (r[1] != NULL)
+ r[1]->up = NULL;
+ h[1] += (2 == join_right (a, rr, r + 1, h[1] - hh, nn));
+ }
+ else
+ {
+ h[1] =
+ hh + (2 ==
+ join_left (a, r + 1, sub_right (a), h[1] - hh,
+ nn));
+ }
+ }
+ else
+ {
+ hh = h[0];
+ ha += (is_lskew (a) ? 2 : 1);
+ h[0] = ha - (is_rskew (a) ? 2 : 1);
+ nn = get_rank (a);
+ n[0] += nn;
+ if (p != NULL)
+ d_ = a != sub_left (p);
+ rbal (a) = 0;
+
+ if (h[0] >= hh)
+ {
+ rr = r[0];
+ r[0] = sub_left (a);
+ if (r[0] != NULL)
+ r[0]->up = NULL;
+ h[0] += (2 == join_left (a, r, rr, hh - h[0], nn));
+ }
+ else
+ {
+ h[0] =
+ hh + (2 ==
+ join_right (a, sub_left (a), r, hh - h[0], nn));
+ }
+ }
+
+ if (--k == 0)
+ break;
+ } /* for p */
+
+ t0->root = r[0];
+ t1->root = r[1];
+ t0->count = n[0] - 1;
+ t1->count = n[1] - 1;
+ } /* if k==0 */
+
+ /* Detach split node */
+ detach_node (sn, t, NULL);
+ t->root = NULL;
+ t->count = 0;
+
+ return 1;
+ }
+}
+
+/* Inorder traversal */
+
+void
+avl_walk (avl_tree t, avl_item_func proc, void *param)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL || t->root == NULL)
+#else
+ if (t->root == NULL)
+#endif
+ return;
+
+ {
+ avl_node *a = t->root, *p;
+
+ while (1)
+ {
+ while (sub_left (a) != NULL)
+ a = sub_left (a);
+
+ while (1)
+ {
+ (*proc) (get_item (a), param);
+ if (sub_right (a) != NULL)
+ break;
+ do
+ {
+ p = a;
+ a = p->up;
+ if (a == NULL)
+ return;
+ }
+ while (p != sub_left (a));
+ }
+ a = sub_right (a);
+ }
+ }
+}
+
+/* recursive helper for 'avl_slice' */
+static int
+node_slice (avl_node ** root, avl_node ** cur, avl_tree tree, avl_size_t len)
+{
+ avl_size_t mid = len / 2;
+
+ if (mid == 0)
+ {
+ if ((*root = new_node ((*cur)->item, /*parent */ NULL, tree)) == NULL)
+ return -1;
+ sub_left (*root) = NULL;
+ sub_right (*root) = NULL;
+ rbal (*root) = 4;
+ *cur = node_next (*cur);
+ return 0;
+
+ }
+ else if ((*root = new_node (NULL, /*parent */ NULL, tree)) == NULL)
+ {
+ return -1;
+ }
+ else
+ {
+ avl_node *p = *root;
+ int h0, h1 = -1;
+
+ rbal (p) = (mid + 1) << 2;
+
+ if ((h0 = node_slice (&sub_left (p), cur, tree, mid)) < 0)
+ return -1;
+
+ p->item = (*tree->copy) ((*cur)->item);
+ sub_left (p)->up = p;
+
+ *cur = node_next (*cur);
+
+ if (len -= mid + 1)
+ {
+ if ((h1 = node_slice (&sub_right (p), cur, tree, len)) < 0)
+ return -1;
+ sub_right (p)->up = p;
+ }
+
+ if (h0 > h1)
+ set_lskew (p);
+ else if (h0 < h1)
+ {
+ set_rskew (p);
+ return 1 + h1;
+ }
+ return 1 + h0;
+ }
+}
+
+/* Return a slice t[lo,hi) as a new tree */
+
+avl_tree
+avl_slice (avl_tree t, avl_size_t lo_idx, avl_size_t hi_idx, void *param)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL)
+ return NULL;
+#endif /* AVL_NULLCHECKS */
+
+ if (lo_idx > hi_idx || lo_idx > t->count)
+ return NULL;
+ if (lo_idx < 1)
+ lo_idx = 1;
+ if (hi_idx > t->count + 1)
+ hi_idx = t->count + 1;
+
+ {
+ avl_tree tt = avl_create (t->compare,
+ t->copy,
+ t->dispose,
+ t->alloc,
+ t->dealloc,
+ param);
+
+ if (tt == NULL)
+ {
+ AVL_SHOW_ERROR ("%s\n",
+ "couldn't allocate new handle in avl_slice()");
+ return NULL;
+ }
+
+ if (lo_idx < hi_idx)
+ {
+ avl_node *cur = node_find_index (lo_idx, t);
+
+ if (node_slice (&tt->root, &cur, t, tt->count = hi_idx - lo_idx) < 0)
+ {
+ AVL_SHOW_ERROR ("%s\n", "couldn't allocate node in avl_slice()");
+ node_empty (tt);
+ (*t->dealloc) (tt);
+ return NULL;
+ }
+ tt->root->up = NULL;
+ }
+ return tt;
+ }
+}
+
+/* recursive helper for 'avl_xload' */
+
+static int
+node_load (avl_node ** root, avl_itersource cur, void **pres, avl_tree desc,
+ avl_size_t len)
+{
+ avl_size_t mid = len / 2;
+
+ if (mid == 0)
+ {
+ if (0 != (*cur->f) (cur, pres)
+ || (*root = new_node (*pres, /*parent */ NULL, desc)) == NULL)
+ return -1;
+ sub_left (*root) = NULL;
+ sub_right (*root) = NULL;
+ rbal (*root) = 4;
+ return 0;
+
+ }
+ else if ((*root = new_node (NULL, /*parent */ NULL, desc)) == NULL)
+ {
+ return -1;
+ }
+ else
+ {
+ avl_node *p = *root;
+ int h0, h1 = -1;
+
+ rbal (p) = (mid + 1) << 2;
+
+ if ((h0 = node_load (&sub_left (p), cur, pres, desc, mid)) < 0)
+ return -1;
+
+ if (0 != (*cur->f) (cur, pres))
+ return -1;
+
+ p->item = (*desc->copy) (*pres);
+ sub_left (p)->up = p;
+
+ if (len -= mid + 1)
+ {
+ if ((h1 = node_load (&sub_right (p), cur, pres, desc, len)) < 0)
+ return -1;
+ sub_right (p)->up = p;
+ }
+
+ if (h0 > h1)
+ set_lskew (p);
+ else if (h0 < h1)
+ {
+ set_rskew (p);
+ return 1 + h1;
+ }
+ return 1 + h0;
+ }
+}
+
+/* Load 'len' items from itersource */
+
+avl_tree
+avl_xload (avl_itersource src, void **pres, avl_size_t len, avl_config conf,
+ void *tree_param)
+{
+#ifndef AVL_NULLCHECKS
+ if (src == NULL)
+ return NULL;
+ {
+#endif /* AVL_NULLCHECKS */
+
+ avl_tree tt = avl_create (conf->compare,
+ conf->copy,
+ conf->dispose,
+ conf->alloc,
+ conf->dealloc,
+ tree_param);
+
+ if (tt == NULL)
+ {
+ AVL_SHOW_ERROR ("%s\n", "couldn't allocate new handle in avl_load()");
+ return NULL;
+ }
+
+ if (len)
+ {
+ if (node_load (&tt->root, src, pres, tt, tt->count = len) < 0)
+ {
+ AVL_SHOW_ERROR ("%s\n", "couldn't allocate node in avl_load()");
+ node_empty (tt);
+ (*tt->dealloc) (tt);
+ return NULL;
+ }
+ tt->root->up = NULL;
+ }
+ return tt;
+#ifndef AVL_NULLCHECKS
+ }
+#endif
+}
+
+#ifdef HAVE_AVL_VERIFY
+
+/* Verification routine */
+typedef enum
+{
+ okay = 0,
+ bad_parent = 1,
+ bad_rank = 2,
+ out_of_balance = 3,
+ out_of_order = 4,
+ diff_mismatch = 5,
+ count_mismatch = 6
+}
+avl_verify_code;
+
+static avl_bool_t
+avl_error (avl_verify_code err)
+{
+ static char *errmess[] = {
+ "Bad parent link",
+ "Rank error",
+ "Out of balance",
+ "Out of order",
+ "Differential mismatch",
+ "Count mismatch"
+ };
+
+ AVL_SHOW_ERROR ("Invalid avl_tree: %s\n", errmess[err - 1]);
+ return avl_false;
+}
+
+static int bals[] = { 1, 0, 2 };
+
+/*
+ helper for recursive 'avl_verify' function
+ return 0 iff okay
+ */
+
+static avl_verify_code
+node_verify (avl_node * root, avl_tree tree, int *h, avl_size_t * c,
+ avl_node * up)
+{
+ avl_verify_code err = okay;
+
+ if (root == NULL)
+ *h = AVL_MIN_DEPTH, *c = 0;
+ else
+ {
+#define AVL_ASSERT(expr,n) if (expr) ; else { err = n; break; }
+#define CHECK(err) if (err) break
+
+ avl_node *left, *right;
+ avl_size_t c_[2];
+ int h_[2], delta;
+
+ left = sub_left (root);
+ right = sub_right (root);
+ do
+ {
+ AVL_ASSERT (root->up == up, bad_parent);
+ CHECK (err = node_verify (left, tree, h_, c_, root));
+ AVL_ASSERT (get_rank (root) == *c_ + 1, bad_rank);
+ CHECK (err = node_verify (right, tree, h_ + 1, c_ + 1, root));
+ delta = h_[1] - h_[0];
+ AVL_ASSERT (delta >= -1 && delta <= +1, out_of_balance);
+ AVL_ASSERT (get_bal (root) == bals[delta + 1], diff_mismatch);
+ AVL_ASSERT (left == NULL
+ || (Item_Compare (tree->compare, tree, get_item (left),
+ get_item (root)) <=
+ 0 CMPERR_CHECK__VERIFY (tree->param)),
+ out_of_order);
+ AVL_ASSERT (right == NULL
+ ||
+ (Item_Compare
+ (tree->compare, tree, get_item (root),
+ get_item (right)) <=
+ 0 CMPERR_CHECK__VERIFY (tree->param)), out_of_order);
+ *h = 1 + (h_[0] > h_[1] ? h_[0] : h_[1]);
+ *c = 1 + c_[0] + c_[1];
+ }
+ while (0);
+ }
+ return err;
+}
+
+avl_bool_t
+avl_verify (avl_tree t)
+{
+#ifndef AVL_NULLCHECKS
+ if (t == NULL)
+ return avl_false;
+#endif /* AVL_NULLCHECKS */
+ {
+ int h;
+ avl_size_t c;
+ avl_verify_code err;
+
+ err = node_verify (t->root, t, &h, &c, (avl_node *) NULL);
+ if (err)
+ return avl_error (err);
+ if (c != t->count)
+ return avl_error (count_mismatch);
+ return avl_true;
+ }
+}
+#endif /* HAVE_AVL_VERIFY */
+
+/****************
+ * *
+ * ITERATORS *
+ * *
+ ****************/
+
+typedef enum
+{
+ AVL_ITERATOR_PRE,
+ AVL_ITERATOR_POST,
+ AVL_ITERATOR_INTREE
+}
+avl_status_t;
+
+struct avl_iterator_
+{
+ avl_node *pos;
+ avl_tree tree;
+ avl_status_t status;
+};
+
+#define get_root(i) i->tree->root
+#define is_pre(i) i->status == AVL_ITERATOR_PRE
+#define is_post(i) i->status == AVL_ITERATOR_POST
+#define set_pre_iterator(i) i->status = AVL_ITERATOR_PRE
+#define set_post_iterator(i) i->status = AVL_ITERATOR_POST
+#define set_in_iterator(i) i->status = AVL_ITERATOR_INTREE
+
+/* Position existing iterator [iter] at node matching [item] in its own tree,
+ * if it exists ; otherwise do nothing
+ */
+
+void
+avl_iterator_seek (const void *item, avl_iterator iter)
+{
+ avl_node *p = node_find (item, iter->tree);
+
+ if (p != NULL)
+ {
+ set_in_iterator (iter);
+ iter->pos = p;
+ }
+}
+
+void
+avl_iterator_seek_index (avl_size_t idx, avl_iterator iter)
+{
+ avl_node *p = node_find_index (idx, iter->tree);
+
+ if (p != NULL)
+ {
+ set_in_iterator (iter);
+ iter->pos = p;
+ }
+}
+
+/* Return item pointer at current position */
+
+void *
+avl_iterator_cur (avl_iterator iter)
+{
+ return iter->pos != NULL ? get_item (iter->pos) : NULL;
+}
+
+avl_size_t
+avl_iterator_count (avl_iterator iter)
+{
+ return iter->tree->count;
+}
+
+avl_size_t
+avl_iterator_index (avl_iterator iter)
+{
+ if (iter->pos != NULL)
+ return get_index (iter->pos);
+ else if (is_pre (iter))
+ return 0;
+ else
+ return iter->tree->count + 1;
+}
+
+/* Rustic: */
+
+avl_iterator
+avl_iterator_new (avl_tree t, avl_ini_t ini, ...)
+{
+ va_list args;
+ avl_iterator iter = NULL;
+
+ va_start (args, ini);
+
+ if (t == NULL)
+ goto finish;
+
+ if ((iter = (*t->alloc) (sizeof (struct avl_iterator_))) == NULL)
+ {
+ AVL_SHOW_ERROR ("%s\n", "couldn't create iterator");
+ goto finish;
+ }
+
+ iter->pos = NULL;
+ iter->tree = t;
+
+ if (ini != AVL_ITERATOR_INI_INTREE)
+ {
+ iter->status =
+ (ini == AVL_ITERATOR_INI_PRE) ? AVL_ITERATOR_PRE : AVL_ITERATOR_POST;
+ }
+ else
+ {
+ const void *item = NULL;
+
+ item = va_arg (args, const void *);
+
+ set_pre_iterator (iter);
+
+ if (item == NULL)
+ AVL_SHOW_ERROR ("%s\n", "missing argument to avl_iterator_new()");
+ else
+ avl_iterator_seek (item, iter);
+ }
+
+finish:
+ va_end (args);
+ return iter;
+}
+
+/*
+ * The following used to write to memory after it was freed.
+ * Corrected by: David Turner <novalis@openplans.org>
+ */
+void
+avl_iterator_kill (avl_iterator iter)
+{
+ if (iter != NULL)
+ {
+ avl_dealloc_func dealloc = iter->tree->dealloc;
+ iter->pos = NULL;
+ iter->tree = NULL;
+ (*dealloc) (iter);
+ }
+}
+
+void *
+avl_iterator_next (avl_iterator iter)
+{
+ avl_node *a = iter->pos;
+
+ if (is_post (iter))
+ return NULL;
+
+ if (is_pre (iter))
+ {
+ a = get_root (iter);
+ if (a != NULL)
+ {
+ a = node_first (a);
+ set_in_iterator (iter);
+ }
+ }
+ else
+ {
+ a = node_next (a);
+ if (a == NULL)
+ set_post_iterator (iter);
+ }
+
+ iter->pos = a;
+ return a != NULL ? get_item (a) : NULL;
+}
+
+void *
+avl_iterator_prev (avl_iterator iter)
+{
+ avl_node *a = iter->pos;
+
+ if (is_pre (iter))
+ return NULL;
+
+ if (is_post (iter))
+ {
+ a = get_root (iter);
+ if (a != NULL)
+ {
+ a = node_last (a);
+ set_in_iterator (iter);
+ }
+ }
+ else
+ {
+ a = node_prev (a);
+ if (a == NULL)
+ set_pre_iterator (iter);
+ }
+
+ iter->pos = a;
+ return a != NULL ? get_item (a) : NULL;
+}
+
+/* Remove node at current position */
+
+/* Move cursor to next position */
+
+avl_code_t
+avl_iterator_del (avl_iterator iter, void **backup)
+{
+ if (iter == NULL || iter->pos == NULL)
+ return 0;
+ {
+ avl_node *a = iter->pos, *p;
+
+ p = node_next (a);
+ if (p == NULL)
+ set_post_iterator (iter);
+ iter->pos = p;
+ return rebalance_del (a, iter->tree, backup);
+ }
+}
diff --git a/Build/source/texk/web2c/mplibdir/avl.h b/Build/source/texk/web2c/mplibdir/avl.h
new file mode 100644
index 00000000000..a78d50b91cf
--- /dev/null
+++ b/Build/source/texk/web2c/mplibdir/avl.h
@@ -0,0 +1,467 @@
+
+/*
+ pyavl -- HEADER FILE "avl.h"
+ Interface to manipulate "objects" of type 'avl_tree' and 'avl_iterator'
+*/
+
+#ifndef __AVL__
+#define __AVL__
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define avl_del mp_avl_del
+#define avl_ins mp_avl_ins
+#define avl_tree mp_avl_tree
+#define avl_entry mp_avl_entry
+#define avl_find mp_avl_find
+#define avl_probe mp_avl_probe
+#define avl_create mp_avl_create
+#define avl_destroy mp_avl_destroy
+
+typedef enum
+{ avl_false, avl_true } avl_bool_t;
+
+#ifndef MPW_C
+#include <inttypes.h>
+typedef int8_t avl_code_t;
+typedef int8_t avl_bal_t;
+typedef uint32_t avl_size_t;
+#else
+#include <MacTypes.h>
+typedef SInt8 avl_code_t;
+typedef SInt8 avl_bal_t;
+typedef UInt32 avl_size_t;
+#endif
+
+typedef int (*avl_compare_func) (void *param, const void *lhs,
+ const void *rhs);
+typedef void *(*avl_item_copy_func) (const void *item);
+typedef void *(*avl_item_dispose_func) (void *item);
+typedef void (*avl_item_func) (const void *item, void *param);
+typedef void *(*avl_alloc_func) (size_t);
+typedef void (*avl_dealloc_func) (void *);
+
+#ifdef AVL_FOR_PYTHON
+#undef AVL_CMPERR
+#undef AVL_NULLCHECKS
+#define AVL_CMPERR 1
+#define AVL_NULLCHECKS 1
+#else
+#ifndef AVL_CMPERR
+#define AVL_CMPERR 0
+#endif
+#ifndef AVL_NULLCHECKS
+#define AVL_NULLCHECKS 0
+#endif
+#endif
+
+#if AVL_CMPERR != 0
+extern avl_code_t avl_errcmp_occurred(void *);
+#endif
+
+/* At minimum, shallow copy */
+
+void *avl_default_item_copy(const void *);
+void *avl_default_item_dispose(void *);
+
+#define AVL_STACK_CAPACITY 32 /* for avl_split() function */
+
+typedef enum
+{
+ AVL_ITERATOR_INI_PRE,
+ AVL_ITERATOR_INI_POST,
+ AVL_ITERATOR_INI_INTREE
+} avl_ini_t;
+
+typedef struct avl_tree_ *avl_tree;
+typedef struct avl_iterator_ *avl_iterator;
+
+typedef struct avl_itersource_ avl_itersource_struct, *avl_itersource;
+
+struct avl_itersource_
+{
+ void *p;
+ /* return nonzero on error */
+ avl_code_t(*f) (avl_itersource from, void **to);
+};
+
+typedef struct
+{
+ avl_compare_func compare;
+ avl_item_copy_func copy;
+ avl_item_dispose_func dispose;
+ avl_alloc_func alloc;
+ avl_dealloc_func dealloc;
+} avl_config_struct, *avl_config;
+
+/* -------------------------------------------------------------------------------------------------/
+ Public Functions
+---------------------------------------------------------------------------------------------------*/
+
+/*
+ --- CREATE ---
+ Return a new tree and set its config.
+ Return NULL on allocation failure.
+ * 'alloc' defaults to malloc from stdlib
+ * 'dealloc' defaults to free from stdlib
+ * 'param' user param/refcon
+*/
+
+avl_tree avl_create(avl_compare_func compare,
+ avl_item_copy_func copy,
+ avl_item_dispose_func dispose,
+ avl_alloc_func alloc,
+ avl_dealloc_func dealloc, void *param);
+
+/*
+ --- RESET ---
+ Empty tree 't' as in 'avl_empty()' and modify its config.
+*/
+
+void
+avl_reset(avl_tree t,
+ avl_compare_func compare,
+ avl_item_copy_func copy,
+ avl_item_dispose_func dispose,
+ avl_alloc_func alloc, avl_dealloc_func dealloc);
+
+/*
+ --- EMPTY ---
+ Empty tree 't', calling its dispose_func for each item in 't'.
+ The config is untouched.
+*/
+
+void avl_empty(avl_tree t);
+
+/*
+ --- DESTROY ---
+ Empty tree 't' and free the handle.
+*/
+
+void avl_destroy(avl_tree t);
+
+/*
+ --- DUPLICATE (COPY) ---
+ Return a copy of tree 't', using its copy_func for each item in 't'.
+ Upon failure to allocate room for some item, return NULL.
+*/
+
+avl_tree avl_dup(avl_tree t, void *param);
+
+/*
+ --- EMPTYNESS ---
+ Return 'avl_true' iff tree 't' is empty (i.e. the handle is NULL or 't' contains no item).
+*/
+
+avl_bool_t avl_isempty(avl_tree t);
+
+/*
+ --- SIZE ---
+ Return number of items contained in tree 't'.
+*/
+
+avl_size_t avl_size(avl_tree t);
+
+/*
+ --- FIRST (MINIMUM) ---
+ Return first item in in-order traversal of 't'.
+ Return NULL if 't' is empty.
+*/
+
+void *avl_first(avl_tree t);
+
+/*
+ --- LAST (MAXIMUM) ---
+ Return last item in in-order traversal of 't'.
+ Return NULL if 't' is empty.
+*/
+
+void *avl_last(avl_tree t);
+
+/*
+ --- FIND MATCHING ITEM ---
+ Find item matching 'item' parameter in tree 't'.
+ Return NULL if it's not found.
+ If there are multiple matches, the first one that is encountered
+ during the search is returned; it may not be the one with lowest rank.
+*/
+
+void *avl_find(const void *item, avl_tree t);
+
+/*
+ --- INDEX (RANK) OF ITEM ---
+ Return smallest index 'i' s.t. 't[i]' matches 'item',
+ or zero if 'item' is not found.
+*/
+
+avl_size_t avl_index(const void *item, avl_tree t);
+
+/*
+ --- SPAN ITEMS ---
+ Return integers 'i,j' s.t. 't[i,j]'
+ i smallest index s.t. t[i] >= lo_item, or t->count+1 and
+ j greatest one s.t. t[j] <= hi_item, or 0.
+ If 'hi_item' is less than 'lo_item' those are swapped.
+ Return codes:
+ 0 success
+ -1 error: tree had no root
+ -2 error: compare failed
+*/
+
+avl_code_t
+avl_span(const void *lo_item,
+ const void *hi_item,
+ avl_tree t, avl_size_t * lo_idx, avl_size_t * hi_idx);
+
+/*
+ --- FIND AT LEAST ---
+ Return smallest item in 't' that is GEQ 'item', or NULL.
+*/
+
+void *avl_find_atleast(const void *item, avl_tree t);
+
+/*
+ --- FIND AT MOST ---
+ Return largest item in 't' that is LEQ 'item', or NULL.
+*/
+
+void *avl_find_atmost(const void *item, avl_tree t);
+
+/*
+ --- FIND BY INDEX (RANK) ---
+ Find item in 't' by index, that is return 't[idx]'.
+ If 'idx' is not in '[1,avl_size(t)]' then return NULL.
+ If a compare failed then return NULL.
+*/
+
+void *avl_find_index(avl_size_t idx, avl_tree t);
+
+/*
+ --- INSERTION ---
+ Insert 'item' in tree 't' with regard to its compare_func.
+ Say 'avl_ins(item,t,avl_true)' to insert 'item' in 't'
+ even if it is there already.
+ If 'item' is a duplicate and 'allow_duplicates' is avl_false,
+ nothing is done.
+ Return codes:
+ -1 error: allocation of new node failed
+ -2 error: compare failed, tree unchanged
+ 0 nothing was done, no error
+ +1 operation successful
+ +2 the same and height(t) increased by one.
+*/
+
+avl_code_t avl_ins(void *item, avl_tree t, avl_bool_t allow_duplicates);
+
+/*
+ --- DELETION ---
+ Remove 'item' from tree 't', calling its dispose_func.
+ To make a backup of 'item' involving its copy_func,
+ say 't(item,backup)' where 'backup' is some pointer to pointer to item.
+ Otherwise set it to NULL.
+ Return codes:
+ 0 item not found
+ -2 error: compare failed, tree unchanged
+ +1 operation successful
+ +2 the same and height(t) decreased by one.
+*/
+
+avl_code_t avl_del(void *item, avl_tree t, void **backup);
+
+/*
+ --- DELETE FIRST ---
+ Remove first item in in-order traversal from tree 't'.
+ Note that only one item is removed.
+ Return +1 or +2 as above.
+*/
+
+avl_code_t avl_del_first(avl_tree t, void **backup);
+
+/*
+ --- DELETE LAST ---
+ Remove last item in in-order traversal from tree 't'.
+ Note that only one item is removed.
+ Return +1 or +2 as above.
+*/
+
+avl_code_t avl_del_last(avl_tree t, void **backup);
+
+/*
+ --- INSERT IN FRONT OF INDEX ---
+ Insert 'item' in tree 't' so that afterwards,
+ 't[idx]=item' except if 'idx<=0' or 'idx>size(t)+1'.
+ To append 'item' to 't' regardless of order,
+ say 'avl_ins_index(item,size+1,t)'.
+*/
+
+avl_code_t avl_ins_index(void *item, avl_size_t idx, avl_tree t);
+
+/*
+ --- DELETE ITEM BY INDEX ---
+ Remove item of rank 'idx' from tree 't' and
+ return +1 or +2 as above except if 'idx' is not in
+ '[1,avl_size(t)]' in which case return 0.
+*/
+
+avl_code_t avl_del_index(avl_size_t idx, avl_tree t, void **backup);
+
+/*
+ --- IN-PLACE CONCATENATION ---
+ Pre-condition: 't0' and 't1' are valid avl_trees
+ Note that the code does not check whether the maximal item in 't0' is LEQ than
+ the minimal item in 't1'.
+ Post-condition: 't0' handles the concatenation of
+ 't0' and 't1' which becomes empty (but its config is untouched).
+*/
+
+void avl_cat(avl_tree t0, avl_tree t1);
+
+/*
+ --- SPLITTING ---
+ Pre-condition: 't0' and 't1' are existing handles.
+ Post-condition: items in 't0' all compare LEQ than 'item'
+ and items in 't1' all compare GEQ than 'item'.
+ This implementation removes one item.
+ Return codes:
+ 0 item not found, no-op
+ -2 compare failed, tree unchanged
+ +1 success
+*/
+
+avl_code_t avl_split(const void *item, avl_tree t, avl_tree t0, avl_tree t1);
+
+/*
+ --- IN-ORDER TRAVERSAL ---
+ Walk tree 't' in in-order, applying 'proc' at each node.
+ The 'param' pointer is passed to 'proc', like this:
+ '(*proc) (item_at_node,param)'.
+*/
+
+void avl_walk(avl_tree t, avl_item_func proc, void *param);
+
+/*
+ --- SLICE ---
+ Create a _new tree_ from the slice 't[lo_idx,hi_idx)'
+ provided 'lo_idx <= hi_idx' and these indices
+ are both in range. If a new tree can't be created
+ or if some item can't be allocated, return NULL.
+ Otherwise if the indices are inconsistent return NULL.
+*/
+
+avl_tree
+avl_slice(avl_tree t, avl_size_t lo_idx, avl_size_t hi_idx, void *param);
+
+/* ----------------------------------------------------------/
+ ITERATORS
+
+ An iterator assigned to a tree 't' is still usable after
+ any item is inserted into 't' and after any item
+ not located at this iterator's current position is
+ deleted. The 'avl_iterator_del()' function may be used
+ to remove the item at the iterator's current position.
+------------------------------------------------------------*/
+
+/*
+ --- ITERATOR --- SEEK
+ Find 'item' in this iterator's tree as in 'avl_find()'
+ and make it the current position.
+*/
+
+void avl_iterator_seek(const void *item, avl_iterator iter);
+
+/*
+ --- ITERATOR --- COUNT
+ Return size of this iterator's tree
+*/
+
+avl_size_t avl_iterator_count(avl_iterator iter);
+
+/*
+ --- ITERATOR --- SEEK BY INDEX
+ Set the current position of 'iter' to 't[idx]'
+ where 't' is the tree that is iterated over.
+*/
+
+void avl_iterator_seek_index(avl_size_t idx, avl_iterator iter);
+
+/*
+ --- ITERATOR --- CURRENT POSITION
+ Return item at current position of 'iter'.
+*/
+
+void *avl_iterator_cur(avl_iterator iter);
+
+/*
+ --- ITERATOR --- INDEX
+ Return rank of current item of 'iter' (as a result of computation)
+ except it returns 0 or size of tree plus one if 'iter' is a pre- or post- iterator.
+*/
+
+avl_size_t avl_iterator_index(avl_iterator iter);
+
+/*
+ --- ITERATOR --- CREATE
+ Return a new cursor for tree 't'.
+ If allocation of an iterator struct is impossible, return NULL.
+ Say 'avl_iterator_new(t, ini)' with 'ini==AVL_ITERATOR_INI_PRE' or 'ini==AVL_ITERATOR_INI_POST'
+ or say 'avl_iterator_new(t, AVL_ITERATOR_INI_INTREE, item_pointer)'
+ to set the iterator's current position via 'avl_iterator_seek(item_pointer,the_iterator)'.
+ In the latter case, the iterator is flagged
+ as pre-iterator if the item is not found.
+*/
+
+avl_iterator avl_iterator_new(avl_tree t, avl_ini_t ini, ...);
+
+/*
+ --- ITERATOR --- KILL
+ Cleanup: free the iterator struct.
+*/
+
+void avl_iterator_kill(avl_iterator iter);
+
+/*
+ --- ITERATOR --- SUCCESSOR
+ Get next item pointer in iterator or NULL.
+ 'iter' is flagged as post-iterator if it's in post-position.
+*/
+
+void *avl_iterator_next(avl_iterator iter);
+
+/*
+ --- ITERATOR --- PREDECESSOR
+ Get next item pointer in iterator or NULL.
+ 'iter' is flagged as pre-iterator if it's in pre-position.
+*/
+
+void *avl_iterator_prev(avl_iterator iter);
+
+/*
+ --- ITERATOR --- DELETION
+ Remove item at current position of iterator 'iter' from its tree, if there is one.
+ Current position is set to next item or iterator is flagged as post-iterator.
+*/
+
+avl_code_t avl_iterator_del(avl_iterator iter, void **backup);
+
+/*
+ --- VERIFICATION ---
+ Return avl_true iff 't' is a valid avl_tree.
+ Note that 'avl_verify(NULL)==avl_false'.
+*/
+
+#ifdef HAVE_AVL_VERIFY
+avl_bool_t avl_verify(avl_tree t);
+#endif /* HAVE_AVL_VERIFY */
+
+/*
+ --- LOAD ---
+ More general version of avl_slice
+*/
+
+avl_tree
+avl_xload(avl_itersource src,
+ void **pres, avl_size_t len, avl_config conf, void *param);
+
+#endif /* __AVL__ */
diff --git a/Build/source/texk/web2c/mplibdir/lmplib.c b/Build/source/texk/web2c/mplibdir/lmplib.c
new file mode 100644
index 00000000000..8e0823ece06
--- /dev/null
+++ b/Build/source/texk/web2c/mplibdir/lmplib.c
@@ -0,0 +1,1238 @@
+/* lmplib.c
+
+ Copyright 2006-2008 Taco Hoekwater <taco@luatex.org>
+
+ This file is part of LuaTeX.
+
+ LuaTeX is free software; you can redistribute it and/or modify it under
+ the terms of the GNU Lesser General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at your
+ option) any later version.
+
+ LuaTeX is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+ License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License along
+ with LuaTeX; if not, see <http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <math.h> /* temporary */
+
+#ifndef pdfTeX
+# include <lua.h>
+# include <lauxlib.h>
+# include <lualib.h>
+#else
+# include <../lua51/lua.h>
+# include <../lua51/lauxlib.h>
+# include <../lua51/lualib.h>
+#endif
+
+#include "mplib.h"
+#include "mplibps.h"
+
+ /*@unused@*/ static const char _svn_version[] =
+ "$Id: lmplib.c 1364 2008-07-04 16:09:46Z taco $ $URL: http://scm.foundry.supelec.fr/svn/luatex/trunk/src/texk/web2c/luatexdir/lua/lmplib.c $";
+
+/* metatable identifiers and tests */
+
+#define MPLIB_METATABLE "MPlib"
+#define MPLIB_FIG_METATABLE "MPlib.fig"
+#define MPLIB_GR_METATABLE "MPlib.gr"
+
+#define is_mp(L,b) (MP *)luaL_checkudata(L,b,MPLIB_METATABLE)
+#define is_fig(L,b) (struct mp_edge_object **)luaL_checkudata(L,b,MPLIB_FIG_METATABLE)
+#define is_gr_object(L,b) (struct mp_graphic_object **)luaL_checkudata(L,b,MPLIB_GR_METATABLE)
+
+/* Lua string pre-hashing */
+
+#define mplib_init_S(a) do { \
+ lua_pushliteral(L,#a); \
+ mplib_##a##_ptr = (char *)lua_tostring(L,-1); \
+ mplib_##a##_index = luaL_ref (L,LUA_REGISTRYINDEX); \
+ } while (0)
+
+#define mplib_push_S(a) do { \
+ lua_rawgeti(L,LUA_REGISTRYINDEX,mplib_##a##_index); \
+ } while (0)
+
+#define mplib_is_S(a,i) (mplib_##a##_ptr==(char *)lua_tostring(L,i))
+
+#define mplib_make_S(a) \
+ static int mplib_##a##_index = 0; \
+ static char *mplib_##a##_ptr = NULL
+
+static int mplib_type_Ses[mp_special_code + 1] = { 0 }; /* [0] is not used */
+
+mplib_make_S(fill);
+mplib_make_S(outline);
+mplib_make_S(text);
+mplib_make_S(special);
+mplib_make_S(start_bounds);
+mplib_make_S(stop_bounds);
+mplib_make_S(start_clip);
+mplib_make_S(stop_clip);
+
+mplib_make_S(left_type);
+mplib_make_S(right_type);
+mplib_make_S(x_coord);
+mplib_make_S(y_coord);
+mplib_make_S(left_x);
+mplib_make_S(left_y);
+mplib_make_S(right_x);
+mplib_make_S(right_y);
+
+mplib_make_S(color);
+mplib_make_S(dash);
+mplib_make_S(depth);
+mplib_make_S(dsize);
+mplib_make_S(font);
+mplib_make_S(height);
+mplib_make_S(htap);
+mplib_make_S(linecap);
+mplib_make_S(linejoin);
+mplib_make_S(miterlimit);
+mplib_make_S(path);
+mplib_make_S(pen);
+mplib_make_S(postscript);
+mplib_make_S(prescript);
+mplib_make_S(transform);
+mplib_make_S(type);
+mplib_make_S(width);
+
+static void mplib_init_Ses(lua_State * L)
+{
+ mplib_init_S(fill);
+ mplib_init_S(outline);
+ mplib_init_S(text);
+ mplib_init_S(start_bounds);
+ mplib_init_S(stop_bounds);
+ mplib_init_S(start_clip);
+ mplib_init_S(stop_clip);
+ mplib_init_S(special);
+
+ mplib_type_Ses[mp_fill_code] = mplib_fill_index;
+ mplib_type_Ses[mp_stroked_code] = mplib_outline_index;
+ mplib_type_Ses[mp_text_code] = mplib_text_index;
+ mplib_type_Ses[mp_start_bounds_code] = mplib_start_bounds_index;
+ mplib_type_Ses[mp_stop_bounds_code] = mplib_stop_bounds_index;
+ mplib_type_Ses[mp_start_clip_code] = mplib_start_clip_index;
+ mplib_type_Ses[mp_stop_clip_code] = mplib_stop_clip_index;
+ mplib_type_Ses[mp_special_code] = mplib_special_index;
+
+ mplib_init_S(left_type);
+ mplib_init_S(right_type);
+ mplib_init_S(x_coord);
+ mplib_init_S(y_coord);
+ mplib_init_S(left_x);
+ mplib_init_S(left_y);
+ mplib_init_S(right_x);
+ mplib_init_S(right_y);
+
+ mplib_init_S(color);
+ mplib_init_S(dash);
+ mplib_init_S(depth);
+ mplib_init_S(dsize);
+ mplib_init_S(font);
+ mplib_init_S(height);
+ mplib_init_S(htap);
+ mplib_init_S(linecap);
+ mplib_init_S(linejoin);
+ mplib_init_S(miterlimit);
+ mplib_init_S(path);
+ mplib_init_S(pen);
+ mplib_init_S(postscript);
+ mplib_init_S(prescript);
+ mplib_init_S(transform);
+ mplib_init_S(type);
+ mplib_init_S(width);
+}
+
+
+/* Enumeration arrays to map MPlib enums to Lua strings */
+
+static const char *interaction_options[] =
+ { "unknown", "batch", "nonstop", "scroll", "errorstop", NULL };
+
+static const char *mplib_filetype_names[] =
+ { "term", "error", "mp", "log", "ps", "mem", "tfm", "map", "pfb", "enc", NULL };
+
+static const char *knot_type_enum[] =
+ { "endpoint", "explicit", "given", "curl", "open", "end_cycle" };
+
+static const char *fill_fields[] =
+ { "type", "path", "htap", "pen", "color", "linejoin", "miterlimit",
+ "prescript", "postscript", NULL };
+
+static const char *stroked_fields[] =
+ { "type", "path", "pen", "color", "linejoin", "miterlimit", "linecap",
+ "dash", "prescript", "postscript", NULL };
+
+static const char *text_fields[] =
+ { "type", "text", "dsize", "font", "color", "width", "height", "depth",
+ "transform", "prescript", "postscript", NULL };
+
+static const char *special_fields[] =
+ { "type", "prescript", NULL };
+
+static const char *start_bounds_fields[] =
+ { "type", "path", NULL };
+
+static const char *start_clip_fields[] =
+ { "type", "path", NULL };
+
+static const char *stop_bounds_fields[] =
+ { "type", NULL };
+
+static const char *stop_clip_fields[] =
+ { "type", NULL };
+
+static const char *no_fields[] =
+ { NULL };
+
+
+/* The list of supported MPlib options (not all make sense) */
+
+typedef enum {
+ P_ERROR_LINE, P_MAX_LINE,
+ P_MAIN_MEMORY, P_HASH_SIZE, P_PARAM_SIZE, P_IN_OPEN, P_RANDOM_SEED,
+ P_INTERACTION, P_INI_VERSION, P_MEM_NAME, P_JOB_NAME, P_FIND_FILE,
+ P__SENTINEL } mplib_parm_idx;
+
+typedef struct {
+ const char *name; /* parameter name */
+ mplib_parm_idx idx; /* parameter index */
+} mplib_parm_struct;
+
+static mplib_parm_struct mplib_parms[] = {
+ {"error_line", P_ERROR_LINE },
+ {"print_line", P_MAX_LINE },
+ {"main_memory", P_MAIN_MEMORY },
+ {"hash_size", P_HASH_SIZE },
+ {"param_size", P_PARAM_SIZE },
+ {"max_in_open", P_IN_OPEN },
+ {"random_seed", P_RANDOM_SEED },
+ {"interaction", P_INTERACTION },
+ {"ini_version", P_INI_VERSION },
+ {"mem_name", P_MEM_NAME },
+ {"job_name", P_JOB_NAME },
+ {"find_file", P_FIND_FILE },
+ {NULL, P__SENTINEL }
+};
+
+
+/* Start by defining the needed callback routines for the library */
+
+static char *mplib_find_file(MP mp, const char *fname, const char *fmode, int ftype)
+{
+ lua_State *L = (lua_State *)mp_userdata(mp);
+ lua_checkstack(L, 4);
+ lua_getfield(L, LUA_REGISTRYINDEX, "mplib_file_finder");
+ if (lua_isfunction(L, -1)) {
+ char *s = NULL, *x = NULL;
+ lua_pushstring(L, fname);
+ lua_pushstring(L, fmode);
+ if (ftype >= mp_filetype_text) {
+ lua_pushnumber(L, (lua_Number)(ftype - mp_filetype_text));
+ } else {
+ lua_pushstring(L, mplib_filetype_names[ftype]);
+ }
+ if (lua_pcall(L, 3, 1, 0) != 0) {
+ fprintf(stdout, "Error in mp.find_file: %s\n",
+ (char *) lua_tostring(L, -1));
+ return NULL;
+ }
+ x = (char *) lua_tostring(L, -1);
+ if (x != NULL)
+ s = strdup(x);
+ lua_pop(L, 1); /* pop the string */
+ return s;
+ } else {
+ lua_pop(L, 1);
+ }
+ if (fmode[0] != 'r' || (!access(fname, R_OK)) || ftype) {
+ return strdup(fname);
+ }
+ return NULL;
+}
+
+static int mplib_find_file_function(lua_State * L)
+{
+ if (!(lua_isfunction(L, -1) || lua_isnil(L, -1))) {
+ return 1; /* error */
+ }
+ lua_pushstring(L, "mplib_file_finder");
+ lua_pushvalue(L, -2);
+ lua_rawset(L, LUA_REGISTRYINDEX);
+ return 0;
+}
+
+#define xfree(A) if ((A)!=NULL) { free((A)); A = NULL; }
+
+static int mplib_new(lua_State * L)
+{
+ MP *mp_ptr;
+ mp_ptr = lua_newuserdata(L, sizeof(MP *));
+ if (mp_ptr) {
+ int i;
+ struct MP_options *options = mp_options();
+ options->userdata = (void *) L;
+ options->noninteractive = 1; /* required ! */
+ options->find_file = mplib_find_file;
+ options->print_found_names = 1;
+ if (lua_type(L, 1) == LUA_TTABLE) {
+ for (i = 0; mplib_parms[i].name != NULL; i++) {
+ lua_getfield(L, 1, mplib_parms[i].name);
+ if (lua_isnil(L, -1)) {
+ lua_pop(L, 1);
+ continue; /* skip unset */
+ }
+ switch (mplib_parms[i].idx) {
+ case P_ERROR_LINE:
+ options->error_line = (int)lua_tointeger(L, -1);
+ if (options->error_line<60) options->error_line =60;
+ if (options->error_line>250) options->error_line = 250;
+ options->half_error_line = (options->error_line/2)+10;
+ break;
+ case P_MAX_LINE:
+ options->max_print_line = (int)lua_tointeger(L, -1);
+ if (options->max_print_line<60) options->max_print_line = 60;
+ break;
+ case P_MAIN_MEMORY:
+ options->main_memory = (int)lua_tointeger(L, -1);
+ break;
+ case P_HASH_SIZE:
+ options->hash_size = (unsigned)lua_tointeger(L, -1);
+ break;
+ case P_PARAM_SIZE:
+ options->param_size = (int)lua_tointeger(L, -1);
+ break;
+ case P_IN_OPEN:
+ options->max_in_open = (int)lua_tointeger(L, -1);
+ break;
+ case P_RANDOM_SEED:
+ options->random_seed = (int)lua_tointeger(L, -1);
+ break;
+ case P_INTERACTION:
+ options->interaction =
+ luaL_checkoption(L, -1, "errorstopmode",
+ interaction_options);
+ break;
+ case P_INI_VERSION:
+ options->ini_version = lua_toboolean(L, -1);
+ break;
+ case P_MEM_NAME:
+ options->mem_name = strdup((char *) lua_tostring(L, -1));
+ break;
+ case P_JOB_NAME:
+ options->job_name = strdup((char *) lua_tostring(L, -1));
+ break;
+ case P_FIND_FILE:
+ if (mplib_find_file_function(L)) { /* error here */
+ fprintf(stdout,
+ "Invalid arguments to mp.new({find_file=...})\n");
+ }
+ break;
+ default:
+ break;
+ }
+ lua_pop(L, 1);
+ }
+ }
+ *mp_ptr = mp_initialize(options);
+ xfree(options->command_line);
+ xfree(options->mem_name);
+ free(options);
+ if (*mp_ptr) {
+ luaL_getmetatable(L, MPLIB_METATABLE);
+ lua_setmetatable(L, -2);
+ return 1;
+ }
+ }
+ lua_pushnil(L);
+ return 1;
+}
+
+static int mplib_collect(lua_State * L)
+{
+ MP *mp_ptr = is_mp(L, 1);
+ if (*mp_ptr != NULL) {
+ (void)mp_finish(*mp_ptr);
+ *mp_ptr = NULL;
+ }
+ return 0;
+}
+
+static int mplib_tostring(lua_State * L)
+{
+ MP *mp_ptr = is_mp(L, 1);
+ if (*mp_ptr != NULL) {
+ (void)lua_pushfstring(L, "<MP %p>", *mp_ptr);
+ return 1;
+ }
+ return 0;
+}
+
+static int mplib_wrapresults(lua_State * L, mp_run_data *res, int status)
+{
+ lua_checkstack(L, 5);
+ lua_newtable(L);
+ if (res->term_out.size != 0) {
+ lua_pushstring(L, res->term_out.data);
+ lua_setfield(L, -2, "term");
+ }
+ if (res->error_out.size != 0) {
+ lua_pushstring(L, res->error_out.data);
+ lua_setfield(L, -2, "error");
+ }
+ if (res->log_out.size != 0) {
+ lua_pushstring(L, res->log_out.data);
+ lua_setfield(L, -2, "log");
+ }
+ if (res->edges != NULL) {
+ struct mp_edge_object **v;
+ struct mp_edge_object *p = res->edges;
+ int i = 1;
+ lua_newtable(L);
+ while (p != NULL) {
+ v = lua_newuserdata(L, sizeof(struct mp_edge_object *));
+ *v = p;
+ luaL_getmetatable(L, MPLIB_FIG_METATABLE);
+ lua_setmetatable(L, -2);
+ lua_rawseti(L, -2, i);
+ i++;
+ p = p->next;
+ }
+ lua_setfield(L, -2, "fig");
+ res->edges = NULL;
+ }
+ lua_pushnumber(L, (lua_Number)status);
+ lua_setfield(L, -2, "status");
+ return 1;
+}
+
+static int mplib_execute(lua_State * L)
+{
+ MP *mp_ptr = is_mp(L, 1);
+ if (*mp_ptr != NULL && lua_isstring(L, 2)) {
+ size_t l;
+ char *s = (char *) lua_tolstring(L, 2, &l);
+ int h = mp_execute(*mp_ptr, s, l);
+ mp_run_data *res = mp_rundata(*mp_ptr);
+ return mplib_wrapresults(L, res, h);
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static int mplib_finish(lua_State * L)
+{
+ MP *mp_ptr = is_mp(L, 1);
+ if (*mp_ptr != NULL) {
+ int i;
+ int h = mp_execute(*mp_ptr,NULL,0);
+ mp_run_data *res = mp_rundata(*mp_ptr);
+ i = mplib_wrapresults(L, res, h);
+ (void)mp_finish(*mp_ptr);
+ *mp_ptr = NULL;
+ return i;
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static int mplib_char_dimension(lua_State * L, int t)
+{
+ MP *mp_ptr = is_mp(L, 1);
+ if (*mp_ptr != NULL) {
+ char *fname = (char *)luaL_checkstring(L,2);
+ int charnum = (int)luaL_checkinteger(L,3);
+ if (charnum<0 || charnum>255) {
+ lua_pushnumber(L, (lua_Number)0);
+ } else {
+ lua_pushnumber(L,(lua_Number)mp_get_char_dimension(*mp_ptr,fname,charnum,t));
+ }
+ } else {
+ lua_pushnumber(L, (lua_Number)0);
+ }
+ return 1;
+}
+
+static int mplib_charwidth(lua_State * L)
+{
+ return mplib_char_dimension(L, 'w');
+}
+
+static int mplib_chardepth(lua_State * L)
+{
+ return mplib_char_dimension(L, 'd');
+}
+
+static int mplib_charheight(lua_State * L)
+{
+ return mplib_char_dimension(L, 'h');
+}
+
+static int mplib_version(lua_State * L)
+{
+ char *s = mp_metapost_version();
+ lua_pushstring(L, s);
+ free(s);
+ return 1;
+}
+
+static int mplib_statistics(lua_State * L)
+{
+ MP *mp_ptr = is_mp(L, 1);
+ if (*mp_ptr != NULL) {
+ lua_newtable(L);
+ lua_pushnumber(L, (lua_Number)mp_memory_usage(*mp_ptr));
+ lua_setfield(L, -2, "main_memory");
+ lua_pushnumber(L, (lua_Number)mp_hash_usage(*mp_ptr));
+ lua_setfield(L, -2, "hash_size");
+ lua_pushnumber(L, (lua_Number)mp_param_usage(*mp_ptr));
+ lua_setfield(L, -2, "param_size");
+ lua_pushnumber(L, (lua_Number)mp_open_usage(*mp_ptr));
+ lua_setfield(L, -2, "max_in_open");
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+
+/* figure methods */
+
+static int mplib_fig_collect(lua_State * L)
+{
+ struct mp_edge_object **hh = is_fig(L, 1);
+ if (*hh != NULL) {
+ mp_gr_toss_objects(*hh);
+ *hh = NULL;
+ }
+ return 0;
+}
+
+static int mplib_fig_body(lua_State * L)
+{
+ int i = 1;
+ struct mp_graphic_object **v;
+ struct mp_graphic_object *p;
+ struct mp_edge_object **hh = is_fig(L, 1);
+ lua_newtable(L);
+ p = (*hh)->body;
+ while (p != NULL) {
+ v = lua_newuserdata(L, sizeof(struct mp_graphic_object *));
+ *v = p;
+ luaL_getmetatable(L, MPLIB_GR_METATABLE);
+ lua_setmetatable(L, -2);
+ lua_rawseti(L, -2, i);
+ i++;
+ p = p->next;
+ }
+ (*hh)->body = NULL; /* prevent double free */
+ return 1;
+}
+
+static int mplib_fig_copy_body(lua_State * L)
+{
+ int i = 1;
+ struct mp_graphic_object **v;
+ struct mp_graphic_object *p;
+ struct mp_edge_object **hh = is_fig(L, 1);
+ lua_newtable(L);
+ p = (*hh)->body;
+ while (p != NULL) {
+ v = lua_newuserdata(L, sizeof(struct mp_graphic_object *));
+ *v = mp_gr_copy_object((*hh)->parent, p);
+ luaL_getmetatable(L, MPLIB_GR_METATABLE);
+ lua_setmetatable(L, -2);
+ lua_rawseti(L, -2, i);
+ i++;
+ p = p->next;
+ }
+ return 1;
+}
+
+
+static int mplib_fig_tostring(lua_State * L)
+{
+ struct mp_edge_object **hh = is_fig(L, 1);
+ (void)lua_pushfstring(L, "<figure %p>", *hh);
+ return 1;
+}
+
+static int mplib_fig_postscript(lua_State * L)
+{
+ mp_run_data *res;
+ struct mp_edge_object **hh = is_fig(L, 1);
+ int prologues = (int)luaL_optnumber(L, 2, (lua_Number)-1);
+ int procset = (int)luaL_optnumber(L, 3, (lua_Number)-1);
+ if (mp_ps_ship_out(*hh, prologues, procset)
+ && (res = mp_rundata((*hh)->parent))
+ && (res->ps_out.size != 0)) {
+ lua_pushstring(L, res->ps_out.data);
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static int mplib_fig_filename(lua_State * L)
+{
+ struct mp_edge_object **hh = is_fig(L, 1);
+ if (*hh != NULL) {
+ char *s = (*hh)->filename;
+ lua_pushstring(L, s);
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static int mplib_fig_width(lua_State * L)
+{
+ struct mp_edge_object **hh = is_fig(L, 1);
+ if (*hh != NULL) {
+ lua_pushnumber(L, (double) (*hh)->width / 65536.0);
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static int mplib_fig_height(lua_State * L)
+{
+ struct mp_edge_object **hh = is_fig(L, 1);
+ if (*hh != NULL) {
+ lua_pushnumber(L, (double) (*hh)->height / 65536.0);
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static int mplib_fig_depth(lua_State * L)
+{
+ struct mp_edge_object **hh = is_fig(L, 1);
+ if (*hh != NULL) {
+ lua_pushnumber(L, (double) (*hh)->depth / 65536.0);
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static int mplib_fig_italcorr(lua_State * L)
+{
+ struct mp_edge_object **hh = is_fig(L, 1);
+ if (*hh != NULL) {
+ lua_pushnumber(L, (double) (*hh)->ital_corr / 65536.0);
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static int mplib_fig_charcode(lua_State * L)
+{
+ struct mp_edge_object **hh = is_fig(L, 1);
+ if (*hh != NULL) {
+ lua_pushnumber(L, (lua_Number)(*hh)->charcode);
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+
+
+static int mplib_fig_bb(lua_State * L)
+{
+ struct mp_edge_object **hh = is_fig(L, 1);
+ lua_newtable(L);
+ lua_pushnumber(L, (double) (*hh)->minx / 65536.0);
+ lua_rawseti(L, -2, 1);
+ lua_pushnumber(L, (double) (*hh)->miny / 65536.0);
+ lua_rawseti(L, -2, 2);
+ lua_pushnumber(L, (double) (*hh)->maxx / 65536.0);
+ lua_rawseti(L, -2, 3);
+ lua_pushnumber(L, (double) (*hh)->maxy / 65536.0);
+ lua_rawseti(L, -2, 4);
+ return 1;
+}
+
+/* object methods */
+
+static int mplib_gr_collect(lua_State * L)
+{
+ struct mp_graphic_object **hh = is_gr_object(L, 1);
+ if (*hh != NULL) {
+ mp_gr_toss_object(*hh);
+ *hh = NULL;
+ }
+ return 0;
+}
+
+static int mplib_gr_tostring(lua_State * L)
+{
+ struct mp_graphic_object **hh = is_gr_object(L, 1);
+ (void)lua_pushfstring(L, "<object %p>", *hh);
+ return 1;
+}
+
+#define pyth(a,b) (sqrt((a)*(a) + (b)*(b)))
+
+#define aspect_bound (10.0/65536.0)
+#define aspect_default (1.0/65536.0)
+
+static double eps = 0.0001;
+
+static double coord_range_x (mp_knot *h, double dz) {
+ double z;
+ double zlo = 0.0, zhi = 0.0;
+ mp_knot *f = h;
+ while (h != NULL) {
+ z = (double)h->x_coord;
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ z = (double)h->right_x;
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ z = (double)h->left_x;
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ h = h->next;
+ if (h==f)
+ break;
+ }
+ return (zhi - zlo <= dz ? aspect_bound : aspect_default);
+}
+
+static double coord_range_y (mp_knot *h, double dz) {
+ double z;
+ double zlo = 0.0, zhi = 0.0;
+ mp_knot *f = h;
+ while (h != NULL) {
+ z = (double)h->y_coord;
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ z = (double)h->right_y;
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ z = (double)h->left_y;
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ h = h->next;
+ if (h==f)
+ break;
+ }
+ return (zhi - zlo <= dz ? aspect_bound : aspect_default);
+}
+
+
+static int mplib_gr_peninfo(lua_State * L) {
+ double x_coord, y_coord, left_x, left_y, right_x, right_y;
+ double wx, wy;
+ double rx = 1.0, sx = 0.0, sy = 0.0, ry = 1.0, tx = 0.0, ty = 0.0;
+ double divider = 1.0;
+ double width = 1.0;
+ mp_knot *p = NULL, *path = NULL;
+ struct mp_graphic_object **hh = is_gr_object(L, -1);
+ if (!*hh) {
+ lua_pushnil(L);
+ return 1;
+ }
+ if ((*hh)->type == mp_fill_code) {
+ p = ((mp_fill_object *)(*hh))->pen_p;
+ path = ((mp_fill_object *)(*hh))->path_p;
+ } else if ((*hh)->type == mp_stroked_code) {
+ p = ((mp_stroked_object *)(*hh))->pen_p;
+ path = ((mp_stroked_object *)(*hh))->path_p;
+ }
+ if (p==NULL || path == NULL) {
+ lua_pushnil(L);
+ return 1;
+ }
+ x_coord = p->x_coord/65536.0;
+ y_coord = p->y_coord/65536.0;
+ left_x = p->left_x/65536.0;
+ left_y = p->left_y/65536.0;
+ right_x = p->right_x/65536.0;
+ right_y = p->right_y/65536.0;
+ if ((right_x == x_coord) && (left_y == y_coord)) {
+ wx = fabs(left_x - x_coord);
+ wy = fabs(right_y - y_coord);
+ } else {
+ wx = pyth(left_x - x_coord, right_x - x_coord);
+ wy = pyth(left_y - y_coord, right_y - y_coord);
+ }
+ if ((wy/coord_range_x(path, wx)) >= (wx/coord_range_y(path, wy)))
+ width = wy;
+ else
+ width = wx;
+ tx = x_coord;
+ ty = y_coord;
+ sx = left_x - tx;
+ rx = left_y - ty;
+ ry = right_x - tx;
+ sy = right_y - ty;
+ if (width !=1.0) {
+ if (width == 0.0) {
+ sx = 1.0; sy = 1.0;
+ } else {
+ rx/=width; ry/=width; sx/=width; sy/=width;
+ }
+ }
+ if (fabs(sx) < eps) sx = eps;
+ if (fabs(sy) < eps) sy = eps;
+ divider = sx*sy - rx*ry;
+ lua_newtable(L);
+ lua_pushnumber(L,width); lua_setfield(L,-2,"width");
+ lua_pushnumber(L,rx); lua_setfield(L,-2,"rx");
+ lua_pushnumber(L,sx); lua_setfield(L,-2,"sx");
+ lua_pushnumber(L,sy); lua_setfield(L,-2,"sy");
+ lua_pushnumber(L,ry); lua_setfield(L,-2,"ry");
+ lua_pushnumber(L,tx); lua_setfield(L,-2,"tx");
+ lua_pushnumber(L,ty); lua_setfield(L,-2,"ty");
+ return 1;
+}
+
+
+static int mplib_gr_fields(lua_State * L)
+{
+ const char **fields;
+ int i;
+ struct mp_graphic_object **hh = is_gr_object(L, 1);
+ if (*hh) {
+ switch ((*hh)->type) {
+ case mp_fill_code:
+ fields = fill_fields;
+ break;
+ case mp_stroked_code:
+ fields = stroked_fields;
+ break;
+ case mp_text_code:
+ fields = text_fields;
+ break;
+ case mp_special_code:
+ fields = special_fields;
+ break;
+ case mp_start_clip_code:
+ fields = start_clip_fields;
+ break;
+ case mp_start_bounds_code:
+ fields = start_bounds_fields;
+ break;
+ case mp_stop_clip_code:
+ fields = stop_clip_fields;
+ break;
+ case mp_stop_bounds_code:
+ fields = stop_bounds_fields;
+ break;
+ default:
+ fields = no_fields;
+ }
+ lua_newtable(L);
+ for (i = 0; fields[i] != NULL; i++) {
+ lua_pushstring(L, fields[i]);
+ lua_rawseti(L, -2, (i + 1));
+ }
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+
+#define mplib_push_number(L,x) lua_pushnumber(L,(lua_Number)(x)/65536.0)
+
+#define MPLIB_PATH 0
+#define MPLIB_PEN 1
+
+static void mplib_push_path(lua_State * L, struct mp_knot *h, int is_pen)
+{
+ struct mp_knot *p; /* for scanning the path */
+ int i = 1;
+ p = h;
+ if (p != NULL) {
+ lua_newtable(L);
+ do {
+ lua_createtable(L, 0, 6);
+ if (!is_pen) {
+ if (p->left_type != mp_explicit) {
+ mplib_push_S(left_type);
+ lua_pushstring(L, knot_type_enum[p->left_type]);
+ lua_rawset(L, -3);
+ }
+ if (p->right_type != mp_explicit) {
+ mplib_push_S(right_type);
+ lua_pushstring(L, knot_type_enum[p->right_type]);
+ lua_rawset(L, -3);
+ }
+ }
+ mplib_push_S(x_coord);
+ mplib_push_number(L, p->x_coord);
+ lua_rawset(L, -3);
+ mplib_push_S(y_coord);
+ mplib_push_number(L, p->y_coord);
+ lua_rawset(L, -3);
+ mplib_push_S(left_x);
+ mplib_push_number(L, p->left_x);
+ lua_rawset(L, -3);
+ mplib_push_S(left_y);
+ mplib_push_number(L, p->left_y);
+ lua_rawset(L, -3);
+ mplib_push_S(right_x);
+ mplib_push_number(L, p->right_x);
+ lua_rawset(L, -3);
+ mplib_push_S(right_y);
+ mplib_push_number(L, p->right_y);
+ lua_rawset(L, -3);
+ lua_rawseti(L, -2, i);
+ i++;
+ if (p->right_type == mp_endpoint) {
+ return;
+ }
+ p = p->next;
+ } while (p != h);
+ } else {
+ lua_pushnil(L);
+ }
+}
+
+/* this assumes that the top of the stack is a table
+ or nil already in the case
+ */
+static void mplib_push_pentype(lua_State * L, struct mp_knot *h)
+{
+ struct mp_knot *p; /* for scanning the path */
+ p = h;
+ if (p == NULL) {
+ /* do nothing */
+ } else if (p == p->next) {
+ mplib_push_S(type);
+ lua_pushstring(L, "elliptical");
+ lua_rawset(L, -3);
+ } else {
+ }
+}
+
+#define set_color_objects(pq) \
+ object_color_model = pq->color_model; \
+ object_color_a = pq->color.a_val; \
+ object_color_b = pq->color.b_val; \
+ object_color_c = pq->color.c_val; \
+ object_color_d = pq->color.d_val;
+
+
+static void mplib_push_color(lua_State * L, struct mp_graphic_object *p)
+{
+ int object_color_model;
+ int object_color_a, object_color_b, object_color_c, object_color_d;
+ if (p != NULL) {
+ if (p->type == mp_fill_code) {
+ mp_fill_object *h = (mp_fill_object *) p;
+ set_color_objects(h);
+ } else if (p->type == mp_stroked_code) {
+ mp_stroked_object *h = (mp_stroked_object *) p;
+ set_color_objects(h);
+ } else {
+ mp_text_object *h = (mp_text_object *) p;
+ set_color_objects(h);
+ }
+ lua_newtable(L);
+ if (object_color_model >= mp_grey_model) {
+ mplib_push_number(L, object_color_a);
+ lua_rawseti(L, -2, 1);
+ if (object_color_model >= mp_rgb_model) {
+ mplib_push_number(L, object_color_b);
+ lua_rawseti(L, -2, 2);
+ mplib_push_number(L, object_color_c);
+ lua_rawseti(L, -2, 3);
+ if (object_color_model == mp_cmyk_model) {
+ mplib_push_number(L, object_color_d);
+ lua_rawseti(L, -2, 4);
+ }
+ }
+ }
+ } else {
+ lua_pushnil(L);
+ }
+}
+
+/* the dash scale is not exported, the field has no external value */
+static void mplib_push_dash(lua_State * L, struct mp_stroked_object *h)
+{
+ mp_dash_object *d;
+ double ds;
+ if (h != NULL && h->dash_p != NULL) {
+ d = h->dash_p;
+ lua_newtable(L);
+ mplib_push_number(L, d->offset);
+ lua_setfield(L, -2, "offset");
+ if (d->array != NULL) {
+ int i = 0;
+ lua_newtable(L);
+ while (*(d->array + i) != -1) {
+ ds = *(d->array + i) / 65536.0;
+ lua_pushnumber(L, ds);
+ i++;
+ lua_rawseti(L, -2, i);
+ }
+ lua_setfield(L, -2, "dashes");
+ }
+ } else {
+ lua_pushnil(L);
+ }
+}
+
+static void mplib_push_transform(lua_State * L, struct mp_text_object *h)
+{
+ int i = 1;
+ if (h != NULL) {
+ lua_createtable(L, 6, 0);
+ mplib_push_number(L, h->tx);
+ lua_rawseti(L, -2, i);
+ i++;
+ mplib_push_number(L, h->ty);
+ lua_rawseti(L, -2, i);
+ i++;
+ mplib_push_number(L, h->txx);
+ lua_rawseti(L, -2, i);
+ i++;
+ mplib_push_number(L, h->tyx);
+ lua_rawseti(L, -2, i);
+ i++;
+ mplib_push_number(L, h->txy);
+ lua_rawseti(L, -2, i);
+ i++;
+ mplib_push_number(L, h->tyy);
+ lua_rawseti(L, -2, i);
+ i++;
+ } else {
+ lua_pushnil(L);
+ }
+}
+
+#define FIELD(A) (mplib_is_S(A,2))
+
+static void mplib_fill(lua_State * L, struct mp_fill_object *h)
+{
+ if (FIELD(path)) {
+ mplib_push_path(L, h->path_p, MPLIB_PATH);
+ } else if (FIELD(htap)) {
+ mplib_push_path(L, h->htap_p, MPLIB_PATH);
+ } else if (FIELD(pen)) {
+ mplib_push_path(L, h->pen_p, MPLIB_PEN);
+ mplib_push_pentype(L, h->pen_p);
+ } else if (FIELD(color)) {
+ mplib_push_color(L, (mp_graphic_object *) h);
+ } else if (FIELD(linejoin)) {
+ lua_pushnumber(L, (lua_Number)h->ljoin);
+ } else if (FIELD(miterlimit)) {
+ mplib_push_number(L, h->miterlim);
+ } else if (FIELD(prescript)) {
+ lua_pushstring(L, h->pre_script);
+ } else if (FIELD(postscript)) {
+ lua_pushstring(L, h->post_script);
+ } else {
+ lua_pushnil(L);
+ }
+}
+
+static void mplib_stroked(lua_State * L, struct mp_stroked_object *h)
+{
+ if (FIELD(path)) {
+ mplib_push_path(L, h->path_p, MPLIB_PATH);
+ } else if (FIELD(pen)) {
+ mplib_push_path(L, h->pen_p, MPLIB_PEN);
+ mplib_push_pentype(L, h->pen_p);
+ } else if (FIELD(color)) {
+ mplib_push_color(L, (mp_graphic_object *) h);
+ } else if (FIELD(dash)) {
+ mplib_push_dash(L, h);
+ } else if (FIELD(linecap)) {
+ lua_pushnumber(L, (lua_Number)h->lcap);
+ } else if (FIELD(linejoin)) {
+ lua_pushnumber(L, (lua_Number)h->ljoin);
+ } else if (FIELD(miterlimit)) {
+ mplib_push_number(L, h->miterlim);
+ } else if (FIELD(prescript)) {
+ lua_pushstring(L, h->pre_script);
+ } else if (FIELD(postscript)) {
+ lua_pushstring(L, h->post_script);
+ } else {
+ lua_pushnil(L);
+ }
+}
+
+static void mplib_text(lua_State * L, struct mp_text_object *h)
+{
+ if (FIELD(text)) {
+ lua_pushstring(L, h->text_p);
+ } else if (FIELD(dsize)) {
+ mplib_push_number(L, (h->font_dsize / 16));
+ } else if (FIELD(font)) {
+ lua_pushstring(L, h->font_name);
+ } else if (FIELD(color)) {
+ mplib_push_color(L, (mp_graphic_object *) h);
+ } else if (FIELD(width)) {
+ mplib_push_number(L, h->width);
+ } else if (FIELD(height)) {
+ mplib_push_number(L, h->height);
+ } else if (FIELD(depth)) {
+ mplib_push_number(L, h->depth);
+ } else if (FIELD(transform)) {
+ mplib_push_transform(L, h);
+ } else if (FIELD(prescript)) {
+ lua_pushstring(L, h->pre_script);
+ } else if (FIELD(postscript)) {
+ lua_pushstring(L, h->post_script);
+ } else {
+ lua_pushnil(L);
+ }
+}
+
+static void mplib_special(lua_State * L, struct mp_special_object *h)
+{
+ if (FIELD(prescript)) {
+ lua_pushstring(L, h->pre_script);
+ } else {
+ lua_pushnil(L);
+ }
+}
+
+static void mplib_start_bounds(lua_State * L, struct mp_bounds_object *h)
+{
+ if (FIELD(path)) {
+ mplib_push_path(L, h->path_p, MPLIB_PATH);
+ } else {
+ lua_pushnil(L);
+ }
+}
+
+static void mplib_start_clip(lua_State * L, struct mp_clip_object *h)
+{
+ if (FIELD(path)) {
+ mplib_push_path(L, h->path_p, MPLIB_PATH);
+ } else {
+ lua_pushnil(L);
+ }
+}
+
+static int mplib_gr_index(lua_State * L)
+{
+ struct mp_graphic_object **hh = is_gr_object(L, 1);
+ if (*hh) {
+ struct mp_graphic_object *h = *hh;
+
+ if (mplib_is_S(type, 2)) {
+ lua_rawgeti(L, LUA_REGISTRYINDEX, mplib_type_Ses[h->type]);
+ } else {
+ switch (h->type) {
+ case mp_fill_code:
+ mplib_fill(L, (mp_fill_object *) h);
+ break;
+ case mp_stroked_code:
+ mplib_stroked(L, (mp_stroked_object *) h);
+ break;
+ case mp_text_code:
+ mplib_text(L, (mp_text_object *) h);
+ break;
+ case mp_special_code:
+ mplib_special(L, (mp_special_object *) h);
+ break;
+ case mp_start_clip_code:
+ mplib_start_clip(L, (mp_clip_object *) h);
+ break;
+ case mp_start_bounds_code:
+ mplib_start_bounds(L, (mp_bounds_object *) h);
+ break;
+ case mp_stop_clip_code:
+ case mp_stop_bounds_code:
+ default:
+ lua_pushnil(L);
+ }
+ }
+ } else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+
+static const struct luaL_reg mplib_meta[] = {
+ {"__gc", mplib_collect},
+ {"__tostring", mplib_tostring},
+ {NULL, NULL} /* sentinel */
+};
+
+static const struct luaL_reg mplib_fig_meta[] = {
+ {"__gc", mplib_fig_collect},
+ {"__tostring", mplib_fig_tostring},
+ {"objects", mplib_fig_body},
+ {"copy_objects", mplib_fig_copy_body},
+ {"filename", mplib_fig_filename},
+ {"postscript", mplib_fig_postscript},
+ {"boundingbox", mplib_fig_bb},
+ {"width", mplib_fig_width},
+ {"height", mplib_fig_height},
+ {"depth", mplib_fig_depth},
+ {"italcorr", mplib_fig_italcorr},
+ {"charcode", mplib_fig_charcode},
+ {NULL, NULL} /* sentinel */
+};
+
+static const struct luaL_reg mplib_gr_meta[] = {
+ {"__gc", mplib_gr_collect},
+ {"__tostring", mplib_gr_tostring},
+ {"__index", mplib_gr_index},
+ {NULL, NULL} /* sentinel */
+};
+
+static const struct luaL_reg mplib_d[] = {
+ {"execute", mplib_execute},
+ {"finish", mplib_finish},
+ {"char_width", mplib_charwidth},
+ {"char_height", mplib_charheight},
+ {"char_depth", mplib_chardepth},
+ {"statistics", mplib_statistics},
+ {NULL, NULL} /* sentinel */
+};
+
+
+static const struct luaL_reg mplib_m[] = {
+ {"new", mplib_new},
+ {"version", mplib_version},
+ {"fields", mplib_gr_fields},
+ {"pen_info", mplib_gr_peninfo},
+ {NULL, NULL} /* sentinel */
+};
+
+
+int luaopen_mplib(lua_State * L)
+{
+ mplib_init_Ses(L);
+
+ luaL_newmetatable(L, MPLIB_GR_METATABLE);
+ lua_pushvalue(L, -1); /* push metatable */
+ lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */
+ luaL_register(L, NULL, mplib_gr_meta); /* object meta methods */
+ lua_pop(L, 1);
+
+ luaL_newmetatable(L, MPLIB_FIG_METATABLE);
+ lua_pushvalue(L, -1); /* push metatable */
+ lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */
+ luaL_register(L, NULL, mplib_fig_meta); /* figure meta methods */
+ lua_pop(L, 1);
+
+ luaL_newmetatable(L, MPLIB_METATABLE);
+ lua_pushvalue(L, -1); /* push metatable */
+ lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */
+ luaL_register(L, NULL, mplib_meta); /* meta methods */
+ luaL_register(L, NULL, mplib_d); /* dict methods */
+ luaL_register(L, "mplib", mplib_m); /* module functions */
+ return 1;
+}
diff --git a/Build/source/texk/web2c/mplibdir/memio.w b/Build/source/texk/web2c/mplibdir/memio.w
new file mode 100644
index 00000000000..d2393d0fb96
--- /dev/null
+++ b/Build/source/texk/web2c/mplibdir/memio.w
@@ -0,0 +1,405 @@
+% $Id: psout.w 616 2008-07-09 14:05:55Z taco $
+%
+% Copyright 2008 Taco Hoekwater.
+%
+% This program is free software: you can redistribute it and/or modify
+% it under the terms of the GNU Lesser General Public License as published by
+% the Free Software Foundation, either version 3 of the License, or
+% (at your option) any later version.
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+% GNU Lesser General Public License for more details.
+%
+% You should have received a copy of the GNU Lesser General Public License
+% along with this program. If not, see <http://www.gnu.org/licenses/>.
+%
+% TeX is a trademark of the American Mathematical Society.
+% METAFONT is a trademark of Addison-Wesley Publishing Company.
+% PostScript is a trademark of Adobe Systems Incorporated.
+
+% Here is TeX material that gets inserted after \input webmac
+
+\font\tenlogo=logo10 % font used for the METAFONT logo
+\def\MP{{\tenlogo META}\-{\tenlogo POST}}
+\def\title{MetaPost MEM reading and writing}
+\def\topofcontents{\hsize 5.5in
+ \vglue -30pt plus 1fil minus 1.5in
+ \def\?##1]{\hbox to 1in{\hfil##1.\ }}
+ }
+\def\botofcontents{\vskip 0pt plus 1fil minus 1.5in}
+\pdfoutput=1
+\pageno=3
+
+@ As usual, need true and false.
+
+@d true 1
+@d false 0
+@d null 0 /* the null pointer */
+@d incr(A) (A)=(A)+1 /* increase a variable by unity */
+@d decr(A) (A)=(A)-1 /* decrease a variable by unity */
+@d qo(A) (A) /* to read eight bits from a quarterword */
+@d qi(A) (quarterword)(A) /* to store eight bits in a quarterword */
+@d max_quarterword 0x3FFF /* largest allowable value in a |quarterword| */
+@d max_halfword 0xFFFFFFF /* largest allowable value in a |halfword| */
+@d max_str_ref 127 /* ``infinite'' number of references */
+
+
+@c
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "mplib.h"
+#include "mpmp.h"
+
+@ @c void mp_store_mem_file (MP mp) {
+ integer k; /* all-purpose index */
+ pointer p,q; /* all-purpose pointers */
+ integer x; /* something to dump */
+ four_quarters w; /* four ASCII codes */
+ memory_word WW;
+ @<Create the |mem_ident|, open the mem file,
+ and inform the user that dumping has begun@>;
+ @<Dump constants for consistency check@>;
+ @<Dump the string pool@>;
+ @<Dump the dynamic memory@>;
+ @<Dump the table of equivalents and the hash table@>;
+ @<Dump a few more things and the closing check word@>;
+ @<Close the mem file@>;
+}
+
+@ Corresponding to the procedure that dumps a mem file, we also have a function
+that reads~one~in. The function returns |false| if the dumped mem is
+incompatible with the present \MP\ table sizes, etc.
+
+@d too_small(A) { wake_up_terminal;
+ wterm_ln("---! Must increase the "); wterm((A));
+@.Must increase the x@>
+ goto OFF_BASE;
+ }
+
+@c
+boolean mp_load_mem_file (MP mp) {
+ integer k; /* all-purpose index */
+ pointer p,q; /* all-purpose pointers */
+ integer x; /* something undumped */
+ str_number s; /* some temporary string */
+ four_quarters w; /* four ASCII codes */
+ memory_word WW;
+ @<Undump the string pool@>;
+ @<Undump the dynamic memory@>;
+ @<Undump the table of equivalents and the hash table@>;
+ @<Undump a few more things and the closing check word@>;
+ return true; /* it worked! */
+OFF_BASE:
+ wake_up_terminal;
+ wterm_ln("(Fatal mem file error; I'm stymied)\n");
+@.Fatal mem file error@>
+ return false;
+}
+
+@ Mem files consist of |memory_word| items, and we use the following
+macros to dump words of different types:
+
+@d dump_wd(A) { WW=(A); (mp->write_binary_file)(mp,mp->mem_file,&WW,sizeof(WW)); }
+@d dump_int(A) { int cint=(A); (mp->write_binary_file)(mp,mp->mem_file,&cint,sizeof(cint)); }
+@d dump_hh(A) { WW.hh=(A); (mp->write_binary_file)(mp,mp->mem_file,&WW,sizeof(WW)); }
+@d dump_qqqq(A) { WW.qqqq=(A); (mp->write_binary_file)(mp,mp->mem_file,&WW,sizeof(WW)); }
+@d dump_string(A) { dump_int((int)(strlen(A)+1));
+ (mp->write_binary_file)(mp,mp->mem_file,A,strlen(A)+1); }
+
+@ The inverse macros are slightly more complicated, since we need to check
+the range of the values we are reading in. We say `|undump(a)(b)(x)|' to
+read an integer value |x| that is supposed to be in the range |a<=x<=b|.
+
+@d mgeti(A) do {
+ size_t wanted = sizeof(A);
+ void *A_ptr = &A;
+ (mp->read_binary_file)(mp, mp->mem_file,&A_ptr,&wanted);
+ if (wanted!=sizeof(A)) goto OFF_BASE;
+} while (0)
+
+@d mgetw(A) do {
+ size_t wanted = sizeof(A);
+ void *A_ptr = &A;
+ (mp->read_binary_file)(mp, mp->mem_file,&A_ptr,&wanted);
+ if (wanted!=sizeof(A)) goto OFF_BASE;
+} while (0)
+
+@d undump_wd(A) { mgetw(WW); A=WW; }
+@d undump_int(A) { int cint; mgeti(cint); A=cint; }
+@d undump_hh(A) { mgetw(WW); A=WW.hh; }
+@d undump_qqqq(A) { mgetw(WW); A=WW.qqqq; }
+@d undump_strings(A,B,C) {
+ undump_int(x); if ( (x<(A)) || (x>(B)) ) goto OFF_BASE; else C=str(x); }
+@d undump(A,B,C) { undump_int(x);
+ if ( (x<(A)) || (x>(int)(B)) ) goto OFF_BASE; else C=x; }
+@d undump_size(A,B,C,D) { undump_int(x);
+ if (x<(A)) goto OFF_BASE;
+ if (x>(B)) too_small((C)); else D=x; }
+@d undump_string(A) {
+ size_t the_wanted;
+ void *the_string;
+ integer XX=0;
+ undump_int(XX);
+ the_wanted = (size_t)XX;
+ the_string = mp_xmalloc(mp,(size_t)XX,1);
+ (mp->read_binary_file)(mp,mp->mem_file,&the_string,&the_wanted);
+ A = (char *)the_string;
+ if (the_wanted!=(size_t)XX) goto OFF_BASE;
+}
+
+@ The next few sections of the program should make it clear how we use the
+dump/undump macros.
+
+@<Dump constants for consistency check@>=
+x = metapost_magic; dump_int(x);
+dump_int(mp->mem_top);
+dump_int((integer)mp->hash_size);
+dump_int(mp->hash_prime)
+dump_int(mp->param_size);
+dump_int(mp->max_in_open);
+
+@ Sections of a \.{WEB} program that are ``commented out'' still contribute
+strings to the string pool; therefore \.{INIMP} and \MP\ will have
+the same strings. (And it is, of course, a good thing that they do.)
+@.WEB@>
+@^string pool@>
+
+@ @c
+int mp_undump_constants (MP mp) {
+ integer x;
+ undump_int(x);
+ if (x!=metapost_magic) return x;
+ undump_int(x); mp->mem_top = x;
+ undump_int(x); mp->hash_size = (unsigned)x;
+ undump_int(x); mp->hash_prime = x;
+ undump_int(x); mp->param_size = x;
+ undump_int(x); mp->max_in_open = x;
+ return metapost_magic;
+ OFF_BASE:
+ return -1;
+}
+
+@ We do string pool compaction to avoid dumping unused strings.
+
+@d dump_four_ASCII
+ w.b0=qi(mp->str_pool[k]); w.b1=qi(mp->str_pool[k+1]);
+ w.b2=qi(mp->str_pool[k+2]); w.b3=qi(mp->str_pool[k+3]);
+ dump_qqqq(w)
+
+@<Dump the string pool@>=
+mp_do_compaction(mp, mp->pool_size);
+dump_int(mp->pool_ptr);
+dump_int(mp->max_str_ptr);
+dump_int(mp->str_ptr);
+k=0;
+while ( (mp->next_str[k]==k+1) && (k<=mp->max_str_ptr) )
+ k++;
+dump_int(k);
+while ( k<=mp->max_str_ptr ) {
+ dump_int(mp->next_str[k]); incr(k);
+}
+k=0;
+while (1) {
+ dump_int(mp->str_start[k]); /* TODO: valgrind warning here */
+ if ( k==mp->str_ptr ) {
+ break;
+ } else {
+ k=mp->next_str[k];
+ }
+}
+k=0;
+while (k+4<mp->pool_ptr ) {
+ dump_four_ASCII; k=k+4;
+}
+k=mp->pool_ptr-4; dump_four_ASCII;
+mp_print_ln(mp); mp_print(mp, "at most "); mp_print_int(mp, mp->max_str_ptr);
+mp_print(mp, " strings of total length ");
+mp_print_int(mp, mp->pool_ptr)
+
+@ @d undump_four_ASCII
+ undump_qqqq(w);
+ mp->str_pool[k]=(ASCII_code)qo(w.b0); mp->str_pool[k+1]=(ASCII_code)qo(w.b1);
+ mp->str_pool[k+2]=(ASCII_code)qo(w.b2); mp->str_pool[k+3]=(ASCII_code)qo(w.b3)
+
+@<Undump the string pool@>=
+undump_int(mp->pool_ptr);
+mp_reallocate_pool(mp, mp->pool_ptr) ;
+undump_int(mp->max_str_ptr);
+mp_reallocate_strings (mp,mp->max_str_ptr) ;
+undump(0,mp->max_str_ptr,mp->str_ptr);
+undump(0,mp->max_str_ptr+1,s);
+for (k=0;k<=s-1;k++)
+ mp->next_str[k]=k+1;
+for (k=s;k<=mp->max_str_ptr;k++)
+ undump(s+1,mp->max_str_ptr+1,mp->next_str[k]);
+mp->fixed_str_use=0;
+k=0;
+while (1) {
+ undump(0,mp->pool_ptr,mp->str_start[k]);
+ if ( k==mp->str_ptr ) break;
+ mp->str_ref[k]=max_str_ref;
+ incr(mp->fixed_str_use);
+ mp->last_fixed_str=k; k=mp->next_str[k];
+}
+k=0;
+while ( k+4<mp->pool_ptr ) {
+ undump_four_ASCII; k=k+4;
+}
+k=mp->pool_ptr-4; undump_four_ASCII;
+mp->init_str_use=mp->fixed_str_use; mp->init_pool_ptr=mp->pool_ptr;
+mp->max_pool_ptr=mp->pool_ptr;
+mp->strs_used_up=mp->fixed_str_use;
+mp->pool_in_use=mp->str_start[mp->str_ptr]; mp->strs_in_use=mp->fixed_str_use;
+mp->max_pl_used=mp->pool_in_use; mp->max_strs_used=mp->strs_in_use;
+mp->pact_count=0; mp->pact_chars=0; mp->pact_strs=0;
+
+@ By sorting the list of available spaces in the variable-size portion of
+|mem|, we are usually able to get by without having to dump very much
+of the dynamic memory.
+
+We recompute |var_used| and |dyn_used|, so that \.{INIMP} dumps valid
+information even when it has not been gathering statistics.
+
+@<Dump the dynamic memory@>=
+mp_sort_avail(mp); mp->var_used=0;
+dump_int(mp->lo_mem_max); dump_int(mp->rover);
+p=0; q=mp->rover; x=0;
+do {
+ for (k=p;k<= q+1;k++)
+ dump_wd(mp->mem[k]);
+ x=x+q+2-p; mp->var_used=mp->var_used+q-p;
+ p=q+node_size(q); q=rmp_link(q);
+} while (q!=mp->rover);
+mp->var_used=mp->var_used+mp->lo_mem_max-p;
+mp->dyn_used=mp->mem_end+1-mp->hi_mem_min;
+for (k=p;k<= mp->lo_mem_max;k++ )
+ dump_wd(mp->mem[k]);
+x=x+mp->lo_mem_max+1-p;
+dump_int(mp->hi_mem_min); dump_int(mp->avail);
+for (k=mp->hi_mem_min;k<=mp->mem_end;k++ )
+ dump_wd(mp->mem[k]);
+x=x+mp->mem_end+1-mp->hi_mem_min;
+p=mp->avail;
+while ( p!=null ) {
+ decr(mp->dyn_used); p=mp_link(p);
+}
+dump_int(mp->var_used); dump_int(mp->dyn_used);
+mp_print_ln(mp); mp_print_int(mp, x);
+mp_print(mp, " memory locations dumped; current usage is ");
+mp_print_int(mp, mp->var_used); mp_print_char(mp, xord('&')); mp_print_int(mp, mp->dyn_used)
+
+@ @<Undump the dynamic memory@>=
+undump(lo_mem_stat_max+1000,hi_mem_stat_min-1,mp->lo_mem_max);
+undump(lo_mem_stat_max+1,mp->lo_mem_max,mp->rover);
+p=0; q=mp->rover;
+do {
+ for (k=p;k<= q+1; k++)
+ undump_wd(mp->mem[k]);
+ p=q+node_size(q);
+ if ( (p>mp->lo_mem_max)||((q>=rmp_link(q))&&(rmp_link(q)!=mp->rover)) )
+ goto OFF_BASE;
+ q=rmp_link(q);
+} while (q!=mp->rover);
+for (k=p;k<=mp->lo_mem_max;k++ )
+ undump_wd(mp->mem[k]);
+undump(mp->lo_mem_max+1,hi_mem_stat_min,mp->hi_mem_min);
+undump(null,mp->mem_top,mp->avail); mp->mem_end=mp->mem_top;
+mp->last_pending=spec_head;
+for (k=mp->hi_mem_min;k<= mp->mem_end;k++)
+ undump_wd(mp->mem[k]);
+undump_int(mp->var_used); undump_int(mp->dyn_used)
+
+@ A different scheme is used to compress the hash table, since its lower region
+is usually sparse. When |text(p)<>0| for |p<=hash_used|, we output three
+words: |p|, |hash[p]|, and |eqtb[p]|. The hash table is, of course, densely
+packed for |p>=hash_used|, so the remaining entries are output in~a~block.
+
+@<Dump the table of equivalents and the hash table@>=
+dump_int(mp->hash_used);
+mp->st_count=frozen_inaccessible-1-mp->hash_used;
+for (p=1;p<=mp->hash_used;p++) {
+ if ( text(p)!=0 ) {
+ dump_int(p); dump_hh(mp->hash[p]); dump_hh(mp->eqtb[p]); incr(mp->st_count);
+ }
+}
+for (p=mp->hash_used+1;p<=(int)hash_end;p++) {
+ dump_hh(mp->hash[p]); dump_hh(mp->eqtb[p]);
+}
+dump_int(mp->st_count);
+mp_print_ln(mp); mp_print_int(mp, mp->st_count); mp_print(mp, " symbolic tokens")
+
+@ @<Undump the table of equivalents and the hash table@>=
+undump(1,frozen_inaccessible,mp->hash_used);
+p=0;
+do {
+ undump(p+1,mp->hash_used,p);
+ undump_hh(mp->hash[p]); undump_hh(mp->eqtb[p]);
+} while (p!=mp->hash_used);
+for (p=mp->hash_used+1;p<=(int)hash_end;p++ ) {
+ undump_hh(mp->hash[p]); undump_hh(mp->eqtb[p]);
+}
+undump_int(mp->st_count)
+
+@ We have already printed a lot of statistics, so we set |mp_tracing_stats:=0|
+to prevent them appearing again.
+
+@<Dump a few more things and the closing check word@>=
+dump_int(mp->max_internal);
+dump_int(mp->int_ptr);
+for (k=1;k<= mp->int_ptr;k++ ) {
+ dump_int(mp->internal[k]);
+ dump_string(mp->int_name[k]);
+}
+dump_int(mp->start_sym);
+dump_int(mp->interaction);
+dump_string(mp->mem_ident);
+dump_int(mp->bg_loc); dump_int(mp->eg_loc); dump_int(mp->serial_no); dump_int(69073);
+mp->internal[mp_tracing_stats]=0
+
+@ @<Undump a few more things and the closing check word@>=
+undump_int(x);
+if (x>mp->max_internal) mp_grow_internals(mp,x);
+undump_int(mp->int_ptr);
+for (k=1;k<= mp->int_ptr;k++) {
+ undump_int(mp->internal[k]);
+ undump_string(mp->int_name[k]);
+}
+undump(0,frozen_inaccessible,mp->start_sym);
+if (mp->interaction==mp_unspecified_mode) {
+ undump(mp_unspecified_mode,mp_error_stop_mode,mp->interaction);
+} else {
+ undump(mp_unspecified_mode,mp_error_stop_mode,x);
+}
+undump_string(mp->mem_ident);
+undump(1,hash_end,mp->bg_loc);
+undump(1,hash_end,mp->eg_loc);
+undump_int(mp->serial_no);
+undump_int(x);
+if (x!=69073) goto OFF_BASE
+
+@ @<Create the |mem_ident|...@>=
+{
+ char *tmp = mp_xmalloc(mp,11,1);
+ mp_xfree(mp->mem_ident);
+ mp->mem_ident = mp_xmalloc(mp,256,1);
+ mp_snprintf(tmp,11,"%04d.%02d.%02d",
+ (int)mp_round_unscaled(mp, mp->internal[mp_year]),
+ (int)mp_round_unscaled(mp, mp->internal[mp_month]),
+ (int)mp_round_unscaled(mp, mp->internal[mp_day]));
+ mp_snprintf(mp->mem_ident,256," (mem=%s %s)",mp->job_name, tmp);
+ mp_xfree(tmp);
+ mp_pack_job_name(mp, ".mem");
+ while (! mp_w_open_out(mp, &mp->mem_file) )
+ mp_prompt_file_name(mp, "mem file name", ".mem");
+ mp_print_nl(mp, "Beginning to dump on file ");
+@.Beginning to dump...@>
+ mp_print(mp, mp->name_of_file);
+ mp_print_nl(mp, mp->mem_ident);
+}
+
+@ @<Close the mem file@>=
+(mp->close_file)(mp,mp->mem_file)
diff --git a/Build/source/texk/web2c/mplibdir/mp.w b/Build/source/texk/web2c/mplibdir/mp.w
new file mode 100644
index 00000000000..1303cf6f9e4
--- /dev/null
+++ b/Build/source/texk/web2c/mplibdir/mp.w
@@ -0,0 +1,26427 @@
+% $Id: mp.w 873 2009-03-19 07:44:11Z taco $
+%
+% Copyright 2008 Taco Hoekwater.
+%
+% This program is free software: you can redistribute it and/or modify
+% it under the terms of the GNU Lesser General Public License as published by
+% the Free Software Foundation, either version 3 of the License, or
+% (at your option) any later version.
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+% GNU Lesser General Public License for more details.
+%
+% You should have received a copy of the GNU Lesser General Public License
+% along with this program. If not, see <http://www.gnu.org/licenses/>.
+%
+% TeX is a trademark of the American Mathematical Society.
+% METAFONT is a trademark of Addison-Wesley Publishing Company.
+% PostScript is a trademark of Adobe Systems Incorporated.
+
+% Here is TeX material that gets inserted after \input webmac
+\def\hang{\hangindent 3em\noindent\ignorespaces}
+\def\textindent#1{\hangindent2.5em\noindent\hbox to2.5em{\hss#1 }\ignorespaces}
+\def\ps{PostScript}
+\def\psqrt#1{\sqrt{\mathstrut#1}}
+\def\k{_{k+1}}
+\def\pct!{{\char`\%}} % percent sign in ordinary text
+\font\tenlogo=logo10 % font used for the METAFONT logo
+\font\logos=logosl10
+\def\MF{{\tenlogo META}\-{\tenlogo FONT}}
+\def\MP{{\tenlogo META}\-{\tenlogo POST}}
+\def\[#1]{\ignorespaces} % left over from pascal web
+\def\<#1>{$\langle#1\rangle$}
+\def\section{\mathhexbox278}
+\let\swap=\leftrightarrow
+\def\round{\mathop{\rm round}\nolimits}
+\mathchardef\vbv="026A % synonym for `\|'
+\def\vb{\relax\ifmmode\vbv\else$\vbv$\fi}
+
+\def\(#1){} % this is used to make section names sort themselves better
+\def\9#1{} % this is used for sort keys in the index via @@:sort key}{entry@@>
+\def\title{MetaPost}
+\pdfoutput=1
+\pageno=3
+
+@* \[1] Introduction.
+
+This is \MP\ by John Hobby, a graphics-language processor based on D. E. Knuth's \MF.
+
+Much of the original Pascal version of this program was copied with
+permission from MF.web Version 1.9. It interprets a language very
+similar to D.E. Knuth's METAFONT, but with changes designed to make it
+more suitable for PostScript output.
+
+The main purpose of the following program is to explain the algorithms of \MP\
+as clearly as possible. However, the program has been written so that it
+can be tuned to run efficiently in a wide variety of operating environments
+by making comparatively few changes. Such flexibility is possible because
+the documentation that follows is written in the \.{WEB} language, which is
+at a higher level than C.
+
+A large piece of software like \MP\ has inherent complexity that cannot
+be reduced below a certain level of difficulty, although each individual
+part is fairly simple by itself. The \.{WEB} language is intended to make
+the algorithms as readable as possible, by reflecting the way the
+individual program pieces fit together and by providing the
+cross-references that connect different parts. Detailed comments about
+what is going on, and about why things were done in certain ways, have
+been liberally sprinkled throughout the program. These comments explain
+features of the implementation, but they rarely attempt to explain the
+\MP\ language itself, since the reader is supposed to be familiar with
+{\sl The {\logos METAFONT\/}book} as well as the manual
+@.WEB@>
+@:METAFONTbook}{\sl The {\logos METAFONT\/}book@>
+{\sl A User's Manual for MetaPost}, Computing Science Technical Report 162,
+AT\AM T Bell Laboratories.
+
+@ The present implementation is a preliminary version, but the possibilities
+for new features are limited by the desire to remain as nearly compatible
+with \MF\ as possible.
+
+On the other hand, the \.{WEB} description can be extended without changing
+the core of the program, and it has been designed so that such
+extensions are not extremely difficult to make.
+The |banner| string defined here should be changed whenever \MP\
+undergoes any modifications, so that it will be clear which version of
+\MP\ might be the guilty party when a problem arises.
+@^extensions to \MP@>
+@^system dependencies@>
+
+@d default_banner "This is MetaPost, Version 1.110" /* printed when \MP\ starts */
+@d true 1
+@d false 0
+
+@(mpmp.h@>=
+#define metapost_version "1.110"
+#define metapost_magic (('M'*256) + 'P')*65536 + 1110
+#define metapost_old_magic (('M'*256) + 'P')*65536 + 1080
+
+@ The external library header for \MP\ is |mplib.h|. It contains a
+few typedefs and the header defintions for the externally used
+fuctions.
+
+The most important of the typedefs is the definition of the structure
+|MP_options|, that acts as a small, configurable front-end to the fairly
+large |MP_instance| structure.
+
+@(mplib.h@>=
+typedef struct MP_instance * MP;
+@<Exported types@>
+typedef struct MP_options {
+ @<Option variables@>
+} MP_options;
+@<Exported function headers@>
+
+@ The internal header file is much longer: it not only lists the complete
+|MP_instance|, but also a lot of functions that have to be available to
+the \ps\ backend, that is defined in a separate \.{WEB} file.
+
+The variables from |MP_options| are included inside the |MP_instance|
+wholesale.
+
+@(mpmp.h@>=
+#include <setjmp.h>
+typedef struct psout_data_struct * psout_data;
+typedef struct svgout_data_struct * svgout_data;
+#ifndef HAVE_BOOLEAN
+typedef int boolean;
+#endif
+#ifndef INTEGER_TYPE
+typedef int integer;
+#endif
+@<Declare helpers@>
+@<Types in the outer block@>
+@<Constants in the outer block@>
+typedef struct MP_instance {
+ @<Option variables@>
+ @<Global variables@>
+} MP_instance;
+@<Internal library declarations@>
+
+@ @c
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <assert.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h> /* for access() */
+#endif
+#include <time.h> /* for struct tm \& co */
+#include "mplib.h"
+#include "mplibps.h" /* external header */
+#include "mplibsvg.h" /* external header */
+#include "mpmp.h" /* internal header */
+#include "mppsout.h" /* internal header */
+#include "mpsvgout.h" /* internal header */
+extern font_number mp_read_font_info (MP mp, char *fname); /* tfmin.w */
+@h
+@<Declarations@>
+@<Basic printing procedures@>
+@<Error handling procedures@>
+
+@ Here are the functions that set up the \MP\ instance.
+
+@<Declarations@> =
+MP_options *mp_options (void);
+MP mp_initialize (MP_options *opt);
+
+@ @c
+MP_options *mp_options (void) {
+ MP_options *opt;
+ size_t l = sizeof(MP_options);
+ opt = malloc(l);
+ if (opt!=NULL) {
+ memset (opt,0,l);
+ opt->ini_version = true;
+ }
+ return opt;
+}
+
+@ @<Internal library declarations@>=
+@<Declare subroutines for parsing file names@>
+
+@ The whole instance structure is initialized with zeroes,
+this greatly reduces the number of statements needed in
+the |Allocate or initialize variables| block.
+
+@d set_callback_option(A) do { mp->A = mp_##A;
+ if (opt->A!=NULL) mp->A = opt->A;
+} while (0)
+
+@c
+static MP mp_do_new (jmp_buf *buf) {
+ MP mp = malloc(sizeof(MP_instance));
+ if (mp==NULL) {
+ xfree(buf);
+ return NULL;
+ }
+ memset(mp,0,sizeof(MP_instance));
+ mp->jump_buf = buf;
+ return mp;
+}
+
+@ @c
+static void mp_free (MP mp) {
+ int k; /* loop variable */
+ @<Dealloc variables@>
+ if (mp->noninteractive) {
+ @<Finish non-interactive use@>;
+ }
+ xfree(mp->jump_buf);
+ xfree(mp);
+}
+
+@ @c
+static void mp_do_initialize ( MP mp) {
+ @<Local variables for initialization@>
+ @<Set initial values of key variables@>
+}
+
+@ This procedure gets things started properly.
+@c
+MP mp_initialize (MP_options *opt) {
+ MP mp;
+ jmp_buf *buf = malloc(sizeof(jmp_buf));
+ if (buf == NULL || setjmp(*buf) != 0)
+ return NULL;
+ mp = mp_do_new(buf);
+ if (mp == NULL)
+ return NULL;
+ mp->userdata=opt->userdata;
+ @<Set |ini_version|@>;
+ mp->noninteractive=opt->noninteractive;
+ set_callback_option(find_file);
+ set_callback_option(open_file);
+ set_callback_option(read_ascii_file);
+ set_callback_option(read_binary_file);
+ set_callback_option(close_file);
+ set_callback_option(eof_file);
+ set_callback_option(flush_file);
+ set_callback_option(write_ascii_file);
+ set_callback_option(write_binary_file);
+ set_callback_option(shipout_backend);
+ if (opt->banner && *(opt->banner)) {
+ mp->banner = xstrdup(opt->banner);
+ } else {
+ mp->banner = xstrdup(default_banner);
+ }
+ if (opt->command_line && *(opt->command_line))
+ mp->command_line = xstrdup(opt->command_line);
+ if (mp->noninteractive) {
+ @<Prepare function pointers for non-interactive use@>;
+ }
+ /* open the terminal for output */
+ t_open_out;
+ @<Find constant sizes@>;
+ @<Allocate or initialize variables@>
+ mp_reallocate_memory(mp,mp->mem_max);
+ mp_reallocate_paths(mp,1000);
+ mp_reallocate_fonts(mp,8);
+ mp->history=mp_fatal_error_stop; /* in case we quit during initialization */
+ @<Check the ``constant'' values...@>;
+ if ( mp->bad>0 ) {
+ char ss[256];
+ mp_snprintf(ss,256,"Ouch---my internal constants have been clobbered!\n"
+ "---case %i",(int)mp->bad);
+ do_fprintf(mp->err_out,(char *)ss);
+@.Ouch...clobbered@>
+ return mp;
+ }
+ mp_do_initialize(mp); /* erase preloaded mem */
+ if (mp->ini_version) {
+ @<Run inimpost commands@>;
+ }
+ if (!mp->noninteractive) {
+ @<Initialize the output routines@>;
+ @<Get the first line of input and prepare to start@>;
+ @<Initializations after first line is read@>;
+ } else {
+ mp->history=mp_spotless;
+ }
+ return mp;
+}
+
+@ @<Initializations after first line is read@>=
+mp_open_log_file(mp);
+mp_set_job_id(mp);
+mp_init_map_file(mp, mp->troff_mode);
+mp->history=mp_spotless; /* ready to go! */
+if (mp->troff_mode) {
+ mp->internal[mp_gtroffmode]=unity;
+ mp->internal[mp_prologues]=unity;
+}
+if ( mp->start_sym>0 ) { /* insert the `\&{everyjob}' symbol */
+ mp->cur_sym=mp->start_sym; mp_back_input(mp);
+}
+
+@ @<Exported function headers@>=
+extern MP_options *mp_options (void);
+extern MP mp_initialize (MP_options *opt) ;
+extern int mp_status(MP mp);
+extern void *mp_userdata(MP mp);
+
+@ @c
+int mp_status(MP mp) { return mp->history; }
+
+@ @c
+void *mp_userdata(MP mp) { return mp->userdata; }
+
+@ The overall \MP\ program begins with the heading just shown, after which
+comes a bunch of procedure declarations and function declarations.
+Finally we will get to the main program, which begins with the
+comment `|start_here|'. If you want to skip down to the
+main program now, you can look up `|start_here|' in the index.
+But the author suggests that the best way to understand this program
+is to follow pretty much the order of \MP's components as they appear in the
+\.{WEB} description you are now reading, since the present ordering is
+intended to combine the advantages of the ``bottom up'' and ``top down''
+approaches to the problem of understanding a somewhat complicated system.
+
+@ Some of the code below is intended to be used only when diagnosing the
+strange behavior that sometimes occurs when \MP\ is being installed or
+when system wizards are fooling around with \MP\ without quite knowing
+what they are doing. Such code will not normally be compiled; it is
+delimited by the preprocessor test `|#ifdef DEBUG .. #endif|'.
+
+@ This program has two important variations: (1) There is a long and slow
+version called \.{INIMP}, which does the extra calculations needed to
+@.INIMP@>
+initialize \MP's internal tables; and (2)~there is a shorter and faster
+production version, which cuts the initialization to a bare minimum.
+
+Which is which is decided at runtime.
+
+@ The following parameters can be changed at compile time to extend or
+reduce \MP's capacity. They may have different values in \.{INIMP} and
+in production versions of \MP.
+@.INIMP@>
+@^system dependencies@>
+
+@<Constants...@>=
+#define file_name_size 255 /* file names shouldn't be longer than this */
+#define bistack_size 1500 /* size of stack for bisection algorithms;
+ should probably be left at this value */
+
+@ Like the preceding parameters, the following quantities can be changed
+to extend or reduce \MP's capacity. But if they are changed,
+it is necessary to rerun the initialization program \.{INIMP}
+@.INIMP@>
+to generate new tables for the production \MP\ program.
+One can't simply make helter-skelter changes to the following constants,
+since certain rather complex initialization
+numbers are computed from them.
+
+@ @<Glob...@>=
+int max_strings; /* maximum number of strings; must not exceed |max_halfword| */
+int pool_size; /* maximum number of characters in strings, including all
+ error messages and help texts, and the names of all identifiers */
+int old_pool_size; /* a helper used by |mp_cat| */
+int mem_max; /* greatest index in \MP's internal |mem| array;
+ must be strictly less than |max_halfword|;
+ must be equal to |mem_top| in \.{INIMP}, otherwise |>=mem_top| */
+int mem_top; /* largest index in the |mem| array dumped by \.{INIMP};
+ must not be greater than |mem_max| */
+int hash_prime; /* a prime number equal to about 85\pct! of |hash_size| */
+
+@ @<Option variables@>=
+int error_line; /* width of context lines on terminal error messages */
+int half_error_line; /* width of first lines of contexts in terminal
+ error messages; should be between 30 and |error_line-15| */
+int halt_on_error; /* do we quit at the first error? */
+int max_print_line; /* width of longest text lines output; should be at least 60 */
+unsigned hash_size; /* maximum number of symbolic tokens,
+ must be less than |max_halfword-3*param_size| */
+int param_size; /* maximum number of simultaneous macro parameters */
+int max_in_open; /* maximum number of input files and error insertions that
+ can be going on simultaneously */
+int main_memory; /* only for options, to set up |mem_max| and |mem_top| */
+void *userdata; /* this allows the calling application to setup local */
+char *banner; /* the banner that is printed to the screen and log */
+
+@ @<Dealloc variables@>=
+xfree(mp->banner);
+
+@
+@d set_value(a,b,c) do { a=c; if (b>c) a=b; } while (0)
+
+@<Allocate or ...@>=
+mp->max_strings=500;
+mp->pool_size=10000;
+mp->old_pool_size=10000;
+set_value(mp->error_line,opt->error_line,79);
+set_value(mp->half_error_line,opt->half_error_line,50);
+if (mp->half_error_line>mp->error_line-15 )
+ mp->half_error_line = mp->error_line-15;
+mp->max_print_line=100;
+set_value(mp->max_print_line,opt->max_print_line,79);
+mp->halt_on_error = (opt->halt_on_error ? true : false);
+
+@ In case somebody has inadvertently made bad settings of the ``constants,''
+\MP\ checks them using a global variable called |bad|.
+
+This is the second of many sections of \MP\ where global variables are
+defined.
+
+@<Glob...@>=
+integer bad; /* is some ``constant'' wrong? */
+
+@ Later on we will say `\ignorespaces|if (mem_max>=max_halfword) bad=10;|',
+or something similar. (We can't do that until |max_halfword| has been defined.)
+
+In case you are wondering about the non-consequtive values of |bad|: some
+of the things that used to be WEB constants are now runtime variables
+with checking at assignment time.
+
+@<Check the ``constant'' values for consistency@>=
+mp->bad=0;
+if ( mp->mem_top<=1100 ) mp->bad=4;
+
+@ Some |goto| labels are used by the following definitions. The label
+`|restart|' is occasionally used at the very beginning of a procedure; and
+the label `|reswitch|' is occasionally used just prior to a |case|
+statement in which some cases change the conditions and we wish to branch
+to the newly applicable case. Loops that are set up with the |loop|
+construction defined below are commonly exited by going to `|done|' or to
+`|found|' or to `|not_found|', and they are sometimes repeated by going to
+`|continue|'. If two or more parts of a subroutine start differently but
+end up the same, the shared code may be gathered together at
+`|common_ending|'.
+
+@ Here are some macros for common programming idioms.
+
+@d incr(A) (A)=(A)+1 /* increase a variable by unity */
+@d decr(A) (A)=(A)-1 /* decrease a variable by unity */
+@d negate(A) (A)=-(A) /* change the sign of a variable */
+@d double(A) (A)=(A)+(A)
+@d odd(A) ((A)%2==1)
+@d do_nothing /* empty statement */
+
+@* \[2] The character set.
+In order to make \MP\ readily portable to a wide variety of
+computers, all of its input text is converted to an internal eight-bit
+code that includes standard ASCII, the ``American Standard Code for
+Information Interchange.'' This conversion is done immediately when each
+character is read in. Conversely, characters are converted from ASCII to
+the user's external representation just before they are output to a
+text file.
+@^ASCII code@>
+
+Such an internal code is relevant to users of \MP\ only with respect to
+the \&{char} and \&{ASCII} operations, and the comparison of strings.
+
+@ Characters of text that have been converted to \MP's internal form
+are said to be of type |ASCII_code|, which is a subrange of the integers.
+
+@<Types...@>=
+typedef unsigned char ASCII_code; /* eight-bit numbers */
+
+@ The present specification of \MP\ has been written under the assumption
+that the character set contains at least the letters and symbols associated
+with ASCII codes 040 through 0176; all of these characters are now
+available on most computer terminals.
+
+@<Types...@>=
+typedef unsigned char text_char; /* the data type of characters in text files */
+
+@ @<Local variables for init...@>=
+integer i;
+
+@ The \MP\ processor converts between ASCII code and
+the user's external character set by means of arrays |xord| and |xchr|
+that are analogous to Pascal's |ord| and |chr| functions.
+
+@(mpmp.h@>=
+#define xchr(A) mp->xchr[(A)]
+#define xord(A) mp->xord[(A)]
+
+@ @<Glob...@>=
+ASCII_code xord[256]; /* specifies conversion of input characters */
+text_char xchr[256]; /* specifies conversion of output characters */
+
+@ The core system assumes all 8-bit is acceptable. If it is not,
+a change file has to alter the below section.
+@^system dependencies@>
+
+Additionally, people with extended character sets can
+assign codes arbitrarily, giving an |xchr| equivalent to whatever
+characters the users of \MP\ are allowed to have in their input files.
+Appropriate changes to \MP's |char_class| table should then be made.
+(Unlike \TeX, each installation of \MP\ has a fixed assignment of category
+codes, called the |char_class|.) Such changes make portability of programs
+more difficult, so they should be introduced cautiously if at all.
+@^character set dependencies@>
+@^system dependencies@>
+
+@<Set initial ...@>=
+for (i=0;i<=0377;i++) { xchr(i)=(text_char)i; }
+
+@ The following system-independent code makes the |xord| array contain a
+suitable inverse to the information in |xchr|. Note that if |xchr[i]=xchr[j]|
+where |i<j<0177|, the value of |xord[xchr[i]]| will turn out to be
+|j| or more; hence, standard ASCII code numbers will be used instead of
+codes below 040 in case there is a coincidence.
+
+@<Set initial ...@>=
+for (i=0;i<=255;i++) {
+ xord(xchr(i))=0177;
+}
+for (i=0200;i<=0377;i++) { xord(xchr(i))=(ASCII_code)i;}
+for (i=0;i<=0176;i++) { xord(xchr(i))=(ASCII_code)i;}
+
+@* \[3] Input and output.
+The bane of portability is the fact that different operating systems treat
+input and output quite differently, perhaps because computer scientists
+have not given sufficient attention to this problem. People have felt somehow
+that input and output are not part of ``real'' programming. Well, it is true
+that some kinds of programming are more fun than others. With existing
+input/output conventions being so diverse and so messy, the only sources of
+joy in such parts of the code are the rare occasions when one can find a
+way to make the program a little less bad than it might have been. We have
+two choices, either to attack I/O now and get it over with, or to postpone
+I/O until near the end. Neither prospect is very attractive, so let's
+get it over with.
+
+The basic operations we need to do are (1)~inputting and outputting of
+text, to or from a file or the user's terminal; (2)~inputting and
+outputting of eight-bit bytes, to or from a file; (3)~instructing the
+operating system to initiate (``open'') or to terminate (``close'') input or
+output from a specified file; (4)~testing whether the end of an input
+file has been reached; (5)~display of bits on the user's screen.
+The bit-display operation will be discussed in a later section; we shall
+deal here only with more traditional kinds of I/O.
+
+@ Finding files happens in a slightly roundabout fashion: the \MP\
+instance object contains a field that holds a function pointer that finds a
+file, and returns its name, or NULL. For this, it receives three
+parameters: the non-qualified name |fname|, the intended |fopen|
+operation type |fmode|, and the type of the file |ftype|.
+
+The file types that are passed on in |ftype| can be used to
+differentiate file searches if a library like kpathsea is used,
+the fopen mode is passed along for the same reason.
+
+@<Types...@>=
+typedef unsigned char eight_bits ; /* unsigned one-byte quantity */
+
+@ @<Exported types@>=
+enum mp_filetype {
+ mp_filetype_terminal = 0, /* the terminal */
+ mp_filetype_error, /* the terminal */
+ mp_filetype_program , /* \MP\ language input */
+ mp_filetype_log, /* the log file */
+ mp_filetype_postscript, /* the postscript output */
+ mp_filetype_memfile, /* memory dumps */
+ mp_filetype_metrics, /* TeX font metric files */
+ mp_filetype_fontmap, /* PostScript font mapping files */
+ mp_filetype_font, /* PostScript type1 font programs */
+ mp_filetype_encoding, /* PostScript font encoding files */
+ mp_filetype_text /* first text file for readfrom and writeto primitives */
+};
+typedef char *(*mp_file_finder)(MP, const char *, const char *, int);
+typedef void *(*mp_file_opener)(MP, const char *, const char *, int);
+typedef char *(*mp_file_reader)(MP, void *, size_t *);
+typedef void (*mp_binfile_reader)(MP, void *, void **, size_t *);
+typedef void (*mp_file_closer)(MP, void *);
+typedef int (*mp_file_eoftest)(MP, void *);
+typedef void (*mp_file_flush)(MP, void *);
+typedef void (*mp_file_writer)(MP, void *, const char *);
+typedef void (*mp_binfile_writer)(MP, void *, void *, size_t);
+
+@ @<Option variables@>=
+mp_file_finder find_file;
+mp_file_opener open_file;
+mp_file_reader read_ascii_file;
+mp_binfile_reader read_binary_file;
+mp_file_closer close_file;
+mp_file_eoftest eof_file;
+mp_file_flush flush_file;
+mp_file_writer write_ascii_file;
+mp_binfile_writer write_binary_file;
+
+@ The default function for finding files is |mp_find_file|. It is
+pretty stupid: it will only find files in the current directory.
+
+This function may disappear altogether, it is currently only
+used for the default font map file.
+
+@c
+static char *mp_find_file (MP mp, const char *fname, const char *fmode, int ftype) {
+ (void) mp;
+ if (fmode[0] != 'r' || (! access (fname,R_OK)) || ftype) {
+ return mp_strdup(fname);
+ }
+ return NULL;
+}
+
+@ Because |mp_find_file| is used so early, it has to be in the helpers
+section.
+
+@<Declarations@>=
+static char *mp_find_file (MP mp, const char *fname, const char *fmode, int ftype) ;
+static void *mp_open_file (MP mp , const char *fname, const char *fmode, int ftype) ;
+static char *mp_read_ascii_file (MP mp, void *f, size_t *size) ;
+static void mp_read_binary_file (MP mp, void *f, void **d, size_t *size) ;
+static void mp_close_file (MP mp, void *f) ;
+static int mp_eof_file (MP mp, void *f) ;
+static void mp_flush_file (MP mp, void *f) ;
+static void mp_write_ascii_file (MP mp, void *f, const char *s) ;
+static void mp_write_binary_file (MP mp, void *f, void *s, size_t t) ;
+
+@ The function to open files can now be very short.
+
+@c
+void *mp_open_file(MP mp, const char *fname, const char *fmode, int ftype) {
+ char realmode[3];
+ (void) mp;
+ realmode[0] = *fmode;
+ realmode[1] = 'b';
+ realmode[2] = 0;
+ if (ftype==mp_filetype_terminal) {
+ return (fmode[0] == 'r' ? stdin : stdout);
+ } else if (ftype==mp_filetype_error) {
+ return stderr;
+ } else if (fname != NULL && (fmode[0] != 'r' || (! access (fname,R_OK)))) {
+ return (void *)fopen(fname, realmode);
+ }
+ return NULL;
+}
+
+@ This is a legacy interface: (almost) all file names pass through |name_of_file|.
+
+@<Glob...@>=
+char name_of_file[file_name_size+1]; /* the name of a system file */
+int name_length;/* this many characters are actually
+ relevant in |name_of_file| (the rest are blank) */
+
+@ If this parameter is true, the terminal and log will report the found
+file names for input files instead of the requested ones.
+It is off by default because it creates an extra filename lookup.
+
+@<Option variables@>=
+int print_found_names; /* configuration parameter */
+
+@ @<Allocate or initialize ...@>=
+mp->print_found_names = (opt->print_found_names>0 ? true : false);
+
+@ The |file_line_error_style| parameter makes \MP\ use a more
+standard compiler error message format instead of the Knuthian
+exclamation mark. It needs the actual version of the current input
+file name, that will be saved by |a_open_in| in the global
+|mp->long_name|.
+
+@<Glob...@>=
+char *long_name;
+
+@ @<Option variables@>=
+int file_line_error_style; /* configuration parameter */
+
+@ @<Allocate or initialize ...@>=
+mp->file_line_error_style = (opt->file_line_error_style>0 ? true : false);
+mp->long_name = NULL;
+
+@ \MP's file-opening procedures return |false| if no file identified by
+|name_of_file| could be opened.
+
+The |OPEN_FILE| macro takes care of the |print_found_names| parameter.
+It is not used for opening a mem file for read, because that file name
+is never printed.
+
+@d OPEN_FILE(A) do {
+ if (mp->print_found_names || mp->file_line_error_style) {
+ char *s = (mp->find_file)(mp,mp->name_of_file,A,ftype);
+ if (s!=NULL) {
+ *f = (mp->open_file)(mp,mp->name_of_file,A, ftype);
+ if (mp->print_found_names) {
+ strncpy(mp->name_of_file,s,file_name_size);
+ }
+ if ((*(A) == 'r') && (ftype == mp_filetype_program)) {
+ xfree(mp->long_name);
+ mp->long_name = xstrdup(s);
+ }
+ xfree(s);
+ } else {
+ *f = NULL;
+ }
+ } else {
+ *f = (mp->open_file)(mp,mp->name_of_file,A, ftype);
+ }
+} while (0);
+return (*f ? true : false)
+
+@c
+static boolean mp_a_open_in (MP mp, void **f, int ftype) {
+ /* open a text file for input */
+ OPEN_FILE("r");
+}
+@#
+boolean mp_w_open_in (MP mp, void **f) {
+ /* open a word file for input */
+ *f = (mp->open_file)(mp,mp->name_of_file,"r",mp_filetype_memfile);
+ return (*f ? true : false);
+}
+@#
+static boolean mp_a_open_out (MP mp, void **f, int ftype) {
+ /* open a text file for output */
+ OPEN_FILE("w");
+}
+@#
+static boolean mp_b_open_out (MP mp, void **f, int ftype) {
+ /* open a binary file for output */
+ OPEN_FILE("w");
+}
+@#
+boolean mp_w_open_out (MP mp, void **f) {
+ /* open a word file for output */
+ int ftype = mp_filetype_memfile;
+ OPEN_FILE("w");
+}
+
+@ @<Internal library ...@>=
+boolean mp_w_open_out (MP mp, void **f);
+
+@ @c
+static char *mp_read_ascii_file (MP mp, void *ff, size_t *size) {
+ int c;
+ size_t len = 0, lim = 128;
+ char *s = NULL;
+ FILE *f = (FILE *)ff;
+ *size = 0;
+ (void) mp; /* for -Wunused */
+ if (f==NULL)
+ return NULL;
+ c = fgetc(f);
+ if (c==EOF)
+ return NULL;
+ s = malloc(lim);
+ if (s==NULL) return NULL;
+ while (c!=EOF && c!='\n' && c!='\r') {
+ if ((len+1)==lim) {
+ s =realloc(s, (lim+(lim>>2)));
+ if (s==NULL) return NULL;
+ lim+=(lim>>2);
+ }
+ s[len++] = c;
+ c =fgetc(f);
+ }
+ if (c=='\r') {
+ c = fgetc(f);
+ if (c!=EOF && c!='\n')
+ ungetc(c,f);
+ }
+ s[len] = 0;
+ *size = len;
+ return s;
+}
+
+@ @c
+void mp_write_ascii_file (MP mp, void *f, const char *s) {
+ (void) mp;
+ if (f!=NULL) {
+ fputs(s,(FILE *)f);
+ }
+}
+
+@ @c
+void mp_read_binary_file (MP mp, void *f, void **data, size_t *size) {
+ size_t len = 0;
+ (void) mp;
+ if (f!=NULL)
+ len = fread(*data,1,*size,(FILE *)f);
+ *size = len;
+}
+
+@ @c
+void mp_write_binary_file (MP mp, void *f, void *s, size_t size) {
+ (void) mp;
+ if (f!=NULL)
+ (void)fwrite(s,size,1,(FILE *)f);
+}
+
+
+@ @c
+void mp_close_file (MP mp, void *f) {
+ (void) mp;
+ if (f!=NULL)
+ fclose((FILE *)f);
+}
+
+@ @c
+int mp_eof_file (MP mp, void *f) {
+ (void) mp;
+ if (f!=NULL)
+ return feof((FILE *)f);
+ else
+ return 1;
+}
+
+@ @c
+void mp_flush_file (MP mp, void *f) {
+ (void) mp;
+ if (f!=NULL)
+ fflush((FILE *)f);
+}
+
+@ Input from text files is read one line at a time, using a routine called
+|input_ln|. This function is defined in terms of global variables called
+|buffer|, |first|, and |last| that will be described in detail later; for
+now, it suffices for us to know that |buffer| is an array of |ASCII_code|
+values, and that |first| and |last| are indices into this array
+representing the beginning and ending of a line of text.
+
+@<Glob...@>=
+size_t buf_size; /* maximum number of characters simultaneously present in
+ current lines of open files */
+ASCII_code *buffer; /* lines of characters being read */
+size_t first; /* the first unused position in |buffer| */
+size_t last; /* end of the line just input to |buffer| */
+size_t max_buf_stack; /* largest index used in |buffer| */
+
+@ @<Allocate or initialize ...@>=
+mp->buf_size = 200;
+mp->buffer = xmalloc((mp->buf_size+1),sizeof(ASCII_code));
+
+@ @<Dealloc variables@>=
+xfree(mp->buffer);
+
+@ @c
+static void mp_reallocate_buffer(MP mp, size_t l) {
+ ASCII_code *buffer;
+ if (l>max_halfword) {
+ mp_confusion(mp,"buffer size"); /* can't happen (I hope) */
+ }
+ buffer = xmalloc((l+1),sizeof(ASCII_code));
+ memcpy(buffer,mp->buffer,(mp->buf_size+1));
+ xfree(mp->buffer);
+ mp->buffer = buffer ;
+ mp->buf_size = l;
+}
+
+@ The |input_ln| function brings the next line of input from the specified
+field into available positions of the buffer array and returns the value
+|true|, unless the file has already been entirely read, in which case it
+returns |false| and sets |last:=first|. In general, the |ASCII_code|
+numbers that represent the next line of the file are input into
+|buffer[first]|, |buffer[first+1]|, \dots, |buffer[last-1]|; and the
+global variable |last| is set equal to |first| plus the length of the
+line. Trailing blanks are removed from the line; thus, either |last=first|
+(in which case the line was entirely blank) or |buffer[last-1]<>" "|.
+@^inner loop@>
+
+The variable |max_buf_stack|, which is used to keep track of how large
+the |buf_size| parameter must be to accommodate the present job, is
+also kept up to date by |input_ln|.
+
+@c
+static boolean mp_input_ln (MP mp, void *f ) {
+ /* inputs the next line or returns |false| */
+ char *s;
+ size_t size = 0;
+ mp->last=mp->first; /* cf.\ Matthew 19\thinspace:\thinspace30 */
+ s = (mp->read_ascii_file)(mp,f, &size);
+ if (s==NULL)
+ return false;
+ if (size>0) {
+ mp->last = mp->first+size;
+ if ( mp->last>=mp->max_buf_stack ) {
+ mp->max_buf_stack=mp->last+1;
+ while ( mp->max_buf_stack>mp->buf_size ) {
+ mp_reallocate_buffer(mp,(mp->buf_size+(mp->buf_size>>2)));
+ }
+ }
+ memcpy((mp->buffer+mp->first),s,size);
+ /* while ( mp->buffer[mp->last]==' ' ) mp->last--; */
+ }
+ free(s);
+ return true;
+}
+
+@ The user's terminal acts essentially like other files of text, except
+that it is used both for input and for output. When the terminal is
+considered an input file, the file variable is called |term_in|, and when it
+is considered an output file the file variable is |term_out|.
+@^system dependencies@>
+
+@<Glob...@>=
+void * term_in; /* the terminal as an input file */
+void * term_out; /* the terminal as an output file */
+void * err_out; /* the terminal as an output file */
+
+@ Here is how to open the terminal files. In the default configuration,
+nothing happens except that the command line (if there is one) is copied
+to the input buffer. The variable |command_line| will be filled by the
+|main| procedure. The copying can not be done earlier in the program
+logic because in the |INI| version, the |buffer| is also used for primitive
+initialization.
+
+@d t_open_out do {/* open the terminal for text output */
+ mp->term_out = (mp->open_file)(mp,"terminal", "w", mp_filetype_terminal);
+ mp->err_out = (mp->open_file)(mp,"error", "w", mp_filetype_error);
+} while (0)
+@d t_open_in do { /* open the terminal for text input */
+ mp->term_in = (mp->open_file)(mp,"terminal", "r", mp_filetype_terminal);
+ if (mp->command_line!=NULL) {
+ mp->last = strlen(mp->command_line);
+ strncpy((char *)mp->buffer,mp->command_line,mp->last);
+ xfree(mp->command_line);
+ } else {
+ mp->last = 0;
+ }
+} while (0)
+
+@<Option variables@>=
+char *command_line;
+
+@ Sometimes it is necessary to synchronize the input/output mixture that
+happens on the user's terminal, and three system-dependent
+procedures are used for this
+purpose. The first of these, |update_terminal|, is called when we want
+to make sure that everything we have output to the terminal so far has
+actually left the computer's internal buffers and been sent.
+The second, |clear_terminal|, is called when we wish to cancel any
+input that the user may have typed ahead (since we are about to
+issue an unexpected error message). The third, |wake_up_terminal|,
+is supposed to revive the terminal if the user has disabled it by
+some instruction to the operating system. The following macros show how
+these operations can be specified:
+@^system dependencies@>
+
+@(mpmp.h@>=
+#define update_terminal (mp->flush_file)(mp,mp->term_out) /* empty the terminal output buffer */
+#define clear_terminal do_nothing /* clear the terminal input buffer */
+#define wake_up_terminal (mp->flush_file)(mp,mp->term_out)
+ /* cancel the user's cancellation of output */
+
+@ We need a special routine to read the first line of \MP\ input from
+the user's terminal. This line is different because it is read before we
+have opened the transcript file; there is sort of a ``chicken and
+egg'' problem here. If the user types `\.{input cmr10}' on the first
+line, or if some macro invoked by that line does such an \.{input},
+the transcript file will be named `\.{cmr10.log}'; but if no \.{input}
+commands are performed during the first line of terminal input, the transcript
+file will acquire its default name `\.{mpout.log}'. (The transcript file
+will not contain error messages generated by the first line before the
+first \.{input} command.)
+
+The first line is even more special. It's nice to let the user start
+running a \MP\ job by typing a command line like `\.{MP cmr10}'; in
+such a case, \MP\ will operate as if the first line of input were
+`\.{cmr10}', i.e., the first line will consist of the remainder of the
+command line, after the part that invoked \MP.
+
+@ Different systems have different ways to get started. But regardless of
+what conventions are adopted, the routine that initializes the terminal
+should satisfy the following specifications:
+
+\yskip\textindent{1)}It should open file |term_in| for input from the
+ terminal. (The file |term_out| will already be open for output to the
+ terminal.)
+
+\textindent{2)}If the user has given a command line, this line should be
+ considered the first line of terminal input. Otherwise the
+ user should be prompted with `\.{**}', and the first line of input
+ should be whatever is typed in response.
+
+\textindent{3)}The first line of input, which might or might not be a
+ command line, should appear in locations |first| to |last-1| of the
+ |buffer| array.
+
+\textindent{4)}The global variable |loc| should be set so that the
+ character to be read next by \MP\ is in |buffer[loc]|. This
+ character should not be blank, and we should have |loc<last|.
+
+\yskip\noindent(It may be necessary to prompt the user several times
+before a non-blank line comes in. The prompt is `\.{**}' instead of the
+later `\.*' because the meaning is slightly different: `\.{input}' need
+not be typed immediately after~`\.{**}'.)
+
+@d loc mp->cur_input.loc_field /* location of first unread character in |buffer| */
+
+@c
+boolean mp_init_terminal (MP mp) { /* gets the terminal input started */
+ t_open_in;
+ if (mp->last!=0) {
+ loc = 0; mp->first = 0;
+ return true;
+ }
+ while (1) {
+ if (!mp->noninteractive) {
+ wake_up_terminal; do_fprintf(mp->term_out,"**"); update_terminal;
+@.**@>
+ }
+ if ( ! mp_input_ln(mp, mp->term_in ) ) { /* this shouldn't happen */
+ do_fprintf(mp->term_out,"\n! End of file on the terminal... why?");
+@.End of file on the terminal@>
+ return false;
+ }
+ loc=(halfword)mp->first;
+ while ( (loc<(int)mp->last)&&(mp->buffer[loc]==' ') )
+ incr(loc);
+ if ( loc<(int)mp->last ) {
+ return true; /* return unless the line was all blank */
+ }
+ if (!mp->noninteractive) {
+ do_fprintf(mp->term_out,"Please type the name of your input file.\n");
+ }
+ }
+}
+
+@ @<Declarations@>=
+static boolean mp_init_terminal (MP mp) ;
+
+
+@* \[4] String handling.
+Symbolic token names and diagnostic messages are variable-length strings
+of eight-bit characters. Many strings \MP\ uses are simply literals
+in the compiled source, like the error messages and the names of the
+internal parameters. Other strings are used or defined from the \MP\ input
+language, and these have to be interned.
+
+\MP\ uses strings more extensively than \MF\ does, but the necessary
+operations can still be handled with a fairly simple data structure.
+The array |str_pool| contains all of the (eight-bit) ASCII codes in all
+of the strings, and the array |str_start| contains indices of the starting
+points of each string. Strings are referred to by integer numbers, so that
+string number |s| comprises the characters |str_pool[j]| for
+|str_start[s]<=j<str_start[ss]| where |ss=next_str[s]|. The string pool
+is allocated sequentially and |str_pool[pool_ptr]| is the next unused
+location. The first string number not currently in use is |str_ptr|
+and |next_str[str_ptr]| begins a list of free string numbers. String
+pool entries |str_start[str_ptr]| up to |pool_ptr| are reserved for a
+string currently being constructed.
+
+String numbers 0 to 255 are reserved for strings that correspond to single
+ASCII characters. This is in accordance with the conventions of \.{WEB},
+@.WEB@>
+which converts single-character strings into the ASCII code number of the
+single character involved, while it converts other strings into integers
+and builds a string pool file. Thus, when the string constant \.{"."} appears
+in the program below, \.{WEB} converts it into the integer 46, which is the
+ASCII code for a period, while \.{WEB} will convert a string like \.{"hello"}
+into some integer greater than~255. String number 46 will presumably be the
+single character `\..'\thinspace; but some ASCII codes have no standard visible
+representation, and \MP\ may need to be able to print an arbitrary
+ASCII character, so the first 256 strings are used to specify exactly what
+should be printed for each of the 256 possibilities.
+
+@<Types...@>=
+typedef int pool_pointer; /* for variables that point into |str_pool| */
+typedef int str_number; /* for variables that point into |str_start| */
+
+@ @<Glob...@>=
+ASCII_code *str_pool; /* the characters */
+pool_pointer *str_start; /* the starting pointers */
+str_number *next_str; /* for linking strings in order */
+pool_pointer pool_ptr; /* first unused position in |str_pool| */
+str_number str_ptr; /* number of the current string being created */
+pool_pointer init_pool_ptr; /* the starting value of |pool_ptr| */
+str_number init_str_use; /* the initial number of strings in use */
+pool_pointer max_pool_ptr; /* the maximum so far of |pool_ptr| */
+str_number max_str_ptr; /* the maximum so far of |str_ptr| */
+
+@ @<Allocate or initialize ...@>=
+mp->str_pool = xmalloc ((mp->pool_size +1),sizeof(ASCII_code));
+mp->str_start = xmalloc ((mp->max_strings+1),sizeof(pool_pointer));
+mp->next_str = xmalloc ((mp->max_strings+1),sizeof(str_number));
+
+@ @<Dealloc variables@>=
+xfree(mp->str_pool);
+xfree(mp->str_start);
+xfree(mp->next_str);
+
+@ Most printing is done from |char *|s, but sometimes not. Here are
+functions that convert an internal string into a |char *| for use
+by the printing routines, and vice versa.
+
+@d str(A) mp_str(mp,A)
+@d rts(A) mp_rts(mp,A)
+@d null_str rts("")
+
+@<Internal ...@>=
+int mp_xstrcmp (const char *a, const char *b);
+char * mp_str (MP mp, str_number s);
+
+@ @<Declarations@>=
+static str_number mp_rts (MP mp, const char *s);
+static str_number mp_make_string (MP mp);
+
+@ @c
+int mp_xstrcmp (const char *a, const char *b) {
+ if (a==NULL && b==NULL)
+ return 0;
+ if (a==NULL)
+ return -1;
+ if (b==NULL)
+ return 1;
+ return strcmp(a,b);
+}
+
+@ The attempt to catch interrupted strings that is in |mp_rts|, is not
+very good: it does not handle nesting over more than one level.
+
+@c
+char * mp_str (MP mp, str_number ss) {
+ char *s;
+ size_t len;
+ if (ss==mp->str_ptr) {
+ return NULL;
+ } else {
+ len = (size_t)length(ss);
+ s = xmalloc(len+1,sizeof(char));
+ strncpy(s,(char *)(mp->str_pool+(mp->str_start[ss])),len);
+ s[len] = 0;
+ return (char *)s;
+ }
+}
+str_number mp_rts (MP mp, const char *s) {
+ int r; /* the new string */
+ int old; /* a possible string in progress */
+ int i=0;
+ if (strlen(s)==0) {
+ return 256;
+ } else if (strlen(s)==1) {
+ return s[0];
+ } else {
+ old=0;
+ str_room((integer)strlen(s));
+ if (mp->str_start[mp->str_ptr]<mp->pool_ptr)
+ old = mp_make_string(mp);
+ while (*s) {
+ append_char(*s);
+ s++;
+ }
+ r = mp_make_string(mp);
+ if (old!=0) {
+ str_room(length(old));
+ while (i<length(old)) {
+ append_char((mp->str_start[old]+i));
+ }
+ mp_flush_string(mp,old);
+ }
+ return r;
+ }
+}
+
+@ Except for |strs_used_up|, the following string statistics are only
+maintained when code between |stat| $\ldots$ |tats| delimiters is not
+commented out:
+
+@<Glob...@>=
+integer strs_used_up; /* strings in use or unused but not reclaimed */
+integer pool_in_use; /* total number of cells of |str_pool| actually in use */
+integer strs_in_use; /* total number of strings actually in use */
+integer max_pl_used; /* maximum |pool_in_use| so far */
+integer max_strs_used; /* maximum |strs_in_use| so far */
+
+@ Several of the elementary string operations are performed using \.{WEB}
+macros instead of functions, because many of the
+operations are done quite frequently and we want to avoid the
+overhead of procedure calls. For example, here is
+a simple macro that computes the length of a string.
+@.WEB@>
+
+@d str_stop(A) mp->str_start[mp->next_str[(A)]] /* one cell past the end of string \# */
+@d length(A) (str_stop((A))-mp->str_start[(A)]) /* the number of characters in string \# */
+
+@ The length of the current string is called |cur_length|. If we decide that
+the current string is not needed, |flush_cur_string| resets |pool_ptr| so that
+|cur_length| becomes zero.
+
+@d cur_length (mp->pool_ptr - mp->str_start[mp->str_ptr])
+@d flush_cur_string mp->pool_ptr=mp->str_start[mp->str_ptr]
+
+@ Strings are created by appending character codes to |str_pool|.
+The |append_char| macro, defined here, does not check to see if the
+value of |pool_ptr| has gotten too high; this test is supposed to be
+made before |append_char| is used.
+
+To test if there is room to append |l| more characters to |str_pool|,
+we shall write |str_room(l)|, which tries to make sure there is enough room
+by compacting the string pool if necessary. If this does not work,
+|do_compaction| aborts \MP\ and gives an apologetic error message.
+
+@d append_char(A) /* put |ASCII_code| \# at the end of |str_pool| */
+{ mp->str_pool[mp->pool_ptr]=(ASCII_code)(A); incr(mp->pool_ptr);
+}
+@d str_room(A) /* make sure that the pool hasn't overflowed */
+ { if ( mp->pool_ptr+(A) > mp->max_pool_ptr ) {
+ if ( mp->pool_ptr+(A) > mp->pool_size ) mp_do_compaction(mp, (A));
+ else mp->max_pool_ptr=mp->pool_ptr+(A); }
+ }
+
+@ The following routine is similar to |str_room(1)| but it uses the
+argument |mp->pool_size| to prevent |do_compaction| from aborting when
+string space is exhausted.
+
+@<Declarations@>=
+static void mp_unit_str_room (MP mp);
+
+@ @c
+void mp_unit_str_room (MP mp) {
+ if ( mp->pool_ptr>=mp->pool_size ) mp_do_compaction(mp, mp->pool_size);
+ if ( mp->pool_ptr>=mp->max_pool_ptr ) mp->max_pool_ptr=mp->pool_ptr+1;
+}
+
+@ \MP's string expressions are implemented in a brute-force way: Every
+new string or substring that is needed is simply copied into the string pool.
+Space is eventually reclaimed by a procedure called |do_compaction| with
+the aid of a simple system system of reference counts.
+@^reference counts@>
+
+The number of references to string number |s| will be |str_ref[s]|. The
+special value |str_ref[s]=max_str_ref=127| is used to denote an unknown
+positive number of references; such strings will never be recycled. If
+a string is ever referred to more than 126 times, simultaneously, we
+put it in this category. Hence a single byte suffices to store each |str_ref|.
+
+@d max_str_ref 127 /* ``infinite'' number of references */
+@d add_str_ref(A) { if ( mp->str_ref[(A)]<max_str_ref ) incr(mp->str_ref[(A)]); }
+
+@<Glob...@>=
+int *str_ref;
+
+@ @<Allocate or initialize ...@>=
+mp->str_ref = xmalloc ((mp->max_strings+1),sizeof(int));
+
+@ @<Dealloc variables@>=
+xfree(mp->str_ref);
+
+@ Here's what we do when a string reference disappears:
+
+@d delete_str_ref(A) {
+ if ( mp->str_ref[(A)]<max_str_ref ) {
+ if ( mp->str_ref[(A)]>1 ) decr(mp->str_ref[(A)]);
+ else mp_flush_string(mp, (A));
+ }
+ }
+
+@<Declarations@>=
+static void mp_flush_string (MP mp,str_number s) ;
+
+@ We can't flush the first set of static strings at all, so there
+is no point in trying
+
+@c
+void mp_flush_string (MP mp,str_number s) {
+ if (length(s)>1) {
+ mp->pool_in_use=mp->pool_in_use-length(s);
+ decr(mp->strs_in_use);
+ if ( mp->next_str[s]!=mp->str_ptr ) {
+ mp->str_ref[s]=0;
+ } else {
+ mp->str_ptr=s;
+ decr(mp->strs_used_up);
+ }
+ mp->pool_ptr=mp->str_start[mp->str_ptr];
+ }
+}
+
+@ C literals cannot be simply added, they need to be set so they can't
+be flushed.
+
+@d intern(A) mp_intern(mp,(A))
+
+@c
+str_number mp_intern (MP mp, const char *s) {
+ str_number r ;
+ r = rts(s);
+ mp->str_ref[r] = max_str_ref;
+ return r;
+}
+
+@ @<Declarations@>=
+static str_number mp_intern (MP mp, const char *s);
+
+
+@ Once a sequence of characters has been appended to |str_pool|, it
+officially becomes a string when the function |make_string| is called.
+This function returns the identification number of the new string as its
+value.
+
+When getting the next unused string number from the linked list, we pretend
+that
+$$ \hbox{|max_str_ptr+1|, |max_str_ptr+2|, $\ldots$, |mp->max_strings|} $$
+are linked sequentially even though the |next_str| entries have not been
+initialized yet. We never allow |str_ptr| to reach |mp->max_strings|;
+|do_compaction| is responsible for making sure of this.
+
+@<Declarations@>=
+static str_number mp_make_string (MP mp);
+
+@ @c
+str_number mp_make_string (MP mp) { /* current string enters the pool */
+ str_number s; /* the new string */
+RESTART:
+ s=mp->str_ptr;
+ mp->str_ptr=mp->next_str[s];
+ if ( mp->str_ptr>mp->max_str_ptr ) {
+ if ( mp->str_ptr==mp->max_strings ) {
+ mp->str_ptr=s;
+ mp_do_compaction(mp, 0);
+ goto RESTART;
+ } else {
+ mp->max_str_ptr=mp->str_ptr;
+ mp->next_str[mp->str_ptr]=mp->max_str_ptr+1;
+ }
+ }
+ mp->str_ref[s]=1;
+ mp->str_start[mp->str_ptr]=mp->pool_ptr;
+ incr(mp->strs_used_up);
+ incr(mp->strs_in_use);
+ mp->pool_in_use=mp->pool_in_use+length(s);
+ if ( mp->pool_in_use>mp->max_pl_used )
+ mp->max_pl_used=mp->pool_in_use;
+ if ( mp->strs_in_use>mp->max_strs_used )
+ mp->max_strs_used=mp->strs_in_use;
+ return s;
+}
+
+@ The most interesting string operation is string pool compaction. The idea
+is to recover unused space in the |str_pool| array by recopying the strings
+to close the gaps created when some strings become unused. All string
+numbers~$k$ where |str_ref[k]=0| are to be linked into the list of free string
+numbers after |str_ptr|. If this fails to free enough pool space we issue an
+|overflow| error unless |needed=mp->pool_size|. Calling |do_compaction|
+with |needed=mp->pool_size| supresses all overflow tests.
+
+The compaction process starts with |last_fixed_str| because all lower numbered
+strings are permanently allocated with |max_str_ref| in their |str_ref| entries.
+
+@<Glob...@>=
+str_number last_fixed_str; /* last permanently allocated string */
+str_number fixed_str_use; /* number of permanently allocated strings */
+
+@ @<Internal library ...@>=
+void mp_do_compaction (MP mp, pool_pointer needed) ;
+
+@ @c
+void mp_do_compaction (MP mp, pool_pointer needed) {
+ str_number str_use; /* a count of strings in use */
+ str_number r,s,t; /* strings being manipulated */
+ pool_pointer p,q; /* destination and source for copying string characters */
+ @<Advance |last_fixed_str| as far as possible and set |str_use|@>;
+ r=mp->last_fixed_str;
+ s=mp->next_str[r];
+ p=mp->str_start[s];
+ while ( s!=mp->str_ptr ) {
+ while ( mp->str_ref[s]==0 ) {
+ @<Advance |s| and add the old |s| to the list of free string numbers;
+ then |break| if |s=str_ptr|@>;
+ }
+ r=s; s=mp->next_str[s];
+ incr(str_use);
+ @<Move string |r| back so that |str_start[r]=p|; make |p| the location
+ after the end of the string@>;
+ }
+DONE:
+ @<Move the current string back so that it starts at |p|@>;
+ if ( needed<mp->pool_size ) {
+ @<Make sure that there is room for another string with |needed| characters@>;
+ }
+ @<Account for the compaction and make sure the statistics agree with the
+ global versions@>;
+ mp->strs_used_up=str_use;
+}
+
+@ @<Advance |last_fixed_str| as far as possible and set |str_use|@>=
+t=mp->next_str[mp->last_fixed_str];
+while (t!=mp->str_ptr && mp->str_ref[t]==max_str_ref) {
+ incr(mp->fixed_str_use);
+ mp->last_fixed_str=t;
+ t=mp->next_str[t];
+}
+str_use=mp->fixed_str_use
+
+@ Because of the way |flush_string| has been written, it should never be
+necessary to |break| here. The extra line of code seems worthwhile to
+preserve the generality of |do_compaction|.
+
+@<Advance |s| and add the old |s| to the list of free string numbers;...@>=
+{
+t=s;
+s=mp->next_str[s];
+mp->next_str[r]=s;
+mp->next_str[t]=mp->next_str[mp->str_ptr];
+mp->next_str[mp->str_ptr]=t;
+if ( s==mp->str_ptr ) goto DONE;
+}
+
+@ The string currently starts at |str_start[r]| and ends just before
+|str_start[s]|. We don't change |str_start[s]| because it might be needed
+to locate the next string.
+
+@<Move string |r| back so that |str_start[r]=p|; make |p| the location...@>=
+q=mp->str_start[r];
+mp->str_start[r]=p;
+while ( q<mp->str_start[s] ) {
+ mp->str_pool[p]=mp->str_pool[q];
+ incr(p); incr(q);
+}
+
+@ Pointers |str_start[str_ptr]| and |pool_ptr| have not been updated. When
+we do this, anything between them should be moved.
+
+@ @<Move the current string back so that it starts at |p|@>=
+q=mp->str_start[mp->str_ptr];
+mp->str_start[mp->str_ptr]=p;
+while ( q<mp->pool_ptr ) {
+ mp->str_pool[p]=mp->str_pool[q];
+ incr(p); incr(q);
+}
+mp->pool_ptr=p
+
+@ We must remember that |str_ptr| is not allowed to reach |mp->max_strings|.
+
+@<Make sure that there is room for another string with |needed| char...@>=
+if ( str_use>=mp->max_strings-1 )
+ mp_reallocate_strings (mp,str_use);
+if ( mp->pool_ptr+needed>mp->max_pool_ptr ) {
+ mp_reallocate_pool(mp, mp->pool_ptr+needed);
+ mp->max_pool_ptr=mp->pool_ptr+needed;
+}
+
+@ @<Internal library ...@>=
+void mp_reallocate_strings (MP mp, str_number str_use) ;
+void mp_reallocate_pool(MP mp, pool_pointer needed) ;
+
+@ @c
+void mp_reallocate_strings (MP mp, str_number str_use) {
+ while ( str_use>=mp->max_strings-1 ) {
+ int l = mp->max_strings + (mp->max_strings/4);
+ XREALLOC (mp->str_ref, l, int);
+ XREALLOC (mp->str_start, l, pool_pointer);
+ XREALLOC (mp->next_str, l, str_number);
+ mp->max_strings = l;
+ }
+}
+void mp_reallocate_pool(MP mp, pool_pointer needed) {
+ while ( needed>mp->pool_size ) {
+ int l = mp->pool_size + (mp->pool_size/4);
+ XREALLOC (mp->str_pool, l, ASCII_code);
+ mp->pool_size = l;
+ }
+}
+
+@ @<Account for the compaction and make sure the statistics agree with...@>=
+if ( (mp->str_start[mp->str_ptr]!=mp->pool_in_use)||(str_use!=mp->strs_in_use) )
+ mp_confusion(mp, "string");
+@:this can't happen string}{\quad string@>
+incr(mp->pact_count);
+mp->pact_chars=mp->pact_chars+mp->pool_ptr-str_stop(mp->last_fixed_str);
+mp->pact_strs=mp->pact_strs+str_use-mp->fixed_str_use;
+
+@ A few more global variables are needed to keep track of statistics when
+|stat| $\ldots$ |tats| blocks are not commented out.
+
+@<Glob...@>=
+integer pact_count; /* number of string pool compactions so far */
+integer pact_chars; /* total number of characters moved during compactions */
+integer pact_strs; /* total number of strings moved during compactions */
+
+@ @<Initialize compaction statistics@>=
+mp->pact_count=0;
+mp->pact_chars=0;
+mp->pact_strs=0;
+
+@ The following subroutine compares string |s| with another string of the
+same length that appears in |buffer| starting at position |k|;
+the result is |true| if and only if the strings are equal.
+
+@c
+static boolean mp_str_eq_buf (MP mp,str_number s, integer k) {
+ /* test equality of strings */
+ pool_pointer j; /* running index */
+ j=mp->str_start[s];
+ while ( j<str_stop(s) ) {
+ if ( mp->str_pool[j++]!=mp->buffer[k++] )
+ return false;
+ }
+ return true;
+}
+
+@ Here is a similar routine, but it compares two strings in the string pool,
+and it does not assume that they have the same length. If the first string
+is lexicographically greater than, less than, or equal to the second,
+the result is respectively positive, negative, or zero.
+
+@c
+static integer mp_str_vs_str (MP mp, str_number s, str_number t) {
+ /* test equality of strings */
+ pool_pointer j,k; /* running indices */
+ integer ls,lt; /* lengths */
+ integer l; /* length remaining to test */
+ ls=length(s); lt=length(t);
+ if ( ls<=lt ) l=ls; else l=lt;
+ j=mp->str_start[s]; k=mp->str_start[t];
+ while ( l-->0 ) {
+ if ( mp->str_pool[j]!=mp->str_pool[k] ) {
+ return (mp->str_pool[j]-mp->str_pool[k]);
+ }
+ j++; k++;
+ }
+ return (ls-lt);
+}
+
+@ The initial values of |str_pool|, |str_start|, |pool_ptr|,
+and |str_ptr| are computed by the \.{INIMP} program, based in part
+on the information that \.{WEB} has output while processing \MP.
+@.INIMP@>
+@^string pool@>
+
+@c
+void mp_get_strings_started (MP mp) {
+ /* initializes the string pool,
+ but returns |false| if something goes wrong */
+ int k; /* small indices or counters */
+ str_number g; /* a new string */
+ mp->pool_ptr=0; mp->str_ptr=0; mp->max_pool_ptr=0; mp->max_str_ptr=0;
+ mp->str_start[0]=0;
+ mp->next_str[0]=1;
+ mp->pool_in_use=0; mp->strs_in_use=0;
+ mp->max_pl_used=0; mp->max_strs_used=0;
+ @<Initialize compaction statistics@>;
+ mp->strs_used_up=0;
+ @<Make the first 256 strings@>;
+ g=mp_make_string(mp); /* string 256 == "" */
+ mp->str_ref[g]=max_str_ref;
+ mp->last_fixed_str=mp->str_ptr-1;
+ mp->fixed_str_use=mp->str_ptr;
+ return;
+}
+
+@ @<Declarations@>=
+static void mp_get_strings_started (MP mp);
+
+@ The first 256 strings will consist of a single character only.
+
+@<Make the first 256...@>=
+for (k=0;k<=255;k++) {
+ append_char(k);
+ g=mp_make_string(mp);
+ mp->str_ref[g]=max_str_ref;
+}
+
+@ The first 128 strings will contain 95 standard ASCII characters, and the
+other 33 characters will be printed in three-symbol form like `\.{\^\^A}'
+unless a system-dependent change is made here. Installations that have
+an extended character set, where for example |xchr[032]=@t\.{'^^Z'}@>|,
+would like string 032 to be printed as the single character 032 instead
+of the three characters 0136, 0136, 0132 (\.{\^\^Z}). On the other hand,
+even people with an extended character set will want to represent string
+015 by \.{\^\^M}, since 015 is ASCII's ``carriage return'' code; the idea is
+to produce visible strings instead of tabs or line-feeds or carriage-returns
+or bell-rings or characters that are treated anomalously in text files.
+
+The boolean expression defined here should be |true| unless \MP\ internal
+code number~|k| corresponds to a non-troublesome visible symbol in the
+local character set.
+If character |k| cannot be printed, and |k<0200|, then character |k+0100| or
+|k-0100| must be printable; moreover, ASCII codes |[060..071, 0141..0146]|
+must be printable.
+@^character set dependencies@>
+@^system dependencies@>
+
+@<Character |k| cannot be printed@>=
+ (k<' ')||(k==127)
+
+@* \[5] On-line and off-line printing.
+Messages that are sent to a user's terminal and to the transcript-log file
+are produced by several `|print|' procedures. These procedures will
+direct their output to a variety of places, based on the setting of
+the global variable |selector|, which has the following possible
+values:
+
+\yskip
+\hang |term_and_log|, the normal setting, prints on the terminal and on the
+ transcript file.
+
+\hang |log_only|, prints only on the transcript file.
+
+\hang |term_only|, prints only on the terminal.
+
+\hang |no_print|, doesn't print at all. This is used only in rare cases
+ before the transcript file is open.
+
+\hang |pseudo|, puts output into a cyclic buffer that is used
+ by the |show_context| routine; when we get to that routine we shall discuss
+ the reasoning behind this curious mode.
+
+\hang |new_string|, appends the output to the current string in the
+ string pool.
+
+\hang |>=write_file| prints on one of the files used for the \&{write}
+@:write_}{\&{write} primitive@>
+ command.
+
+\yskip
+\noindent The symbolic names `|term_and_log|', etc., have been assigned
+numeric codes that satisfy the convenient relations |no_print+1=term_only|,
+|no_print+2=log_only|, |term_only+2=log_only+1=term_and_log|. These
+relations are not used when |selector| could be |pseudo|, or |new_string|.
+We need not check for unprintable characters when |selector<pseudo|.
+
+Three additional global variables, |tally|, |term_offset| and |file_offset|
+record the number of characters that have been printed
+since they were most recently cleared to zero. We use |tally| to record
+the length of (possibly very long) stretches of printing; |term_offset|,
+and |file_offset|, on the other hand, keep track of how many
+characters have appeared so far on the current line that has been output
+to the terminal, the transcript file, or the \ps\ output file, respectively.
+
+@d new_string 0 /* printing is deflected to the string pool */
+@d pseudo 2 /* special |selector| setting for |show_context| */
+@d no_print 3 /* |selector| setting that makes data disappear */
+@d term_only 4 /* printing is destined for the terminal only */
+@d log_only 5 /* printing is destined for the transcript file only */
+@d term_and_log 6 /* normal |selector| setting */
+@d write_file 7 /* first write file selector */
+
+@<Glob...@>=
+void * log_file; /* transcript of \MP\ session */
+void * output_file; /* the generic font output goes here */
+unsigned int selector; /* where to print a message */
+unsigned char dig[23]; /* digits in a number, for rounding */
+integer tally; /* the number of characters recently printed */
+unsigned int term_offset;
+ /* the number of characters on the current terminal line */
+unsigned int file_offset;
+ /* the number of characters on the current file line */
+ASCII_code *trick_buf; /* circular buffer for pseudoprinting */
+integer trick_count; /* threshold for pseudoprinting, explained later */
+integer first_count; /* another variable for pseudoprinting */
+
+@ @<Allocate or initialize ...@>=
+mp->trick_buf = xmalloc((mp->error_line+1),sizeof(ASCII_code));
+
+@ @<Dealloc variables@>=
+xfree(mp->trick_buf);
+
+@ @<Initialize the output routines@>=
+mp->selector=term_only; mp->tally=0; mp->term_offset=0; mp->file_offset=0;
+
+@ Macro abbreviations for output to the terminal and to the log file are
+defined here for convenience. Some systems need special conventions
+for terminal output, and it is possible to adhere to those conventions
+by changing |wterm|, |wterm_ln|, and |wterm_cr| here.
+@^system dependencies@>
+
+@(mpmp.h@>=
+#define do_fprintf(f,b) (mp->write_ascii_file)(mp,f,b)
+#define wterm(A) do_fprintf(mp->term_out,(A))
+#define wterm_chr(A) { unsigned char ss[2]; ss[0]=(A); ss[1]='\0'; wterm((char *)ss);}
+#define wterm_cr do_fprintf(mp->term_out,"\n")
+#define wterm_ln(A) { wterm_cr; do_fprintf(mp->term_out,(A)); }
+#define wlog(A) do_fprintf(mp->log_file,(A))
+#define wlog_chr(A) { unsigned char ss[2]; ss[0]=(A); ss[1]='\0'; wlog((char *)ss);}
+#define wlog_cr do_fprintf(mp->log_file, "\n")
+#define wlog_ln(A) { wlog_cr; do_fprintf(mp->log_file,(A)); }
+
+
+@ To end a line of text output, we call |print_ln|. Cases |0..max_write_files|
+use an array |wr_file| that will be declared later.
+
+@d mp_print_text(A) mp_print_str(mp,text((A)))
+
+@<Internal library ...@>=
+void mp_print (MP mp, const char *s);
+void mp_print_ln (MP mp);
+void mp_print_visible_char (MP mp, ASCII_code s);
+void mp_print_char (MP mp, ASCII_code k);
+void mp_print_str (MP mp, str_number s);
+void mp_print_nl (MP mp, const char *s);
+void mp_print_two (MP mp,scaled x, scaled y) ;
+void mp_print_scaled (MP mp,scaled s);
+
+@ @<Basic print...@>=
+void mp_print_ln (MP mp) { /* prints an end-of-line */
+ switch (mp->selector) {
+ case term_and_log:
+ wterm_cr; wlog_cr;
+ mp->term_offset=0; mp->file_offset=0;
+ break;
+ case log_only:
+ wlog_cr; mp->file_offset=0;
+ break;
+ case term_only:
+ wterm_cr; mp->term_offset=0;
+ break;
+ case no_print:
+ case pseudo:
+ case new_string:
+ break;
+ default:
+ do_fprintf(mp->wr_file[(mp->selector-write_file)],"\n");
+ }
+} /* note that |tally| is not affected */
+
+@ The |print_visible_char| procedure sends one character to the desired
+destination, using the |xchr| array to map it into an external character
+compatible with |input_ln|. (It assumes that it is always called with
+a visible ASCII character.) All printing comes through |print_ln| or
+|print_char|, which ultimately calls |print_visible_char|, hence these
+routines are the ones that limit lines to at most |max_print_line| characters.
+But we must make an exception for the \ps\ output file since it is not safe
+to cut up lines arbitrarily in \ps.
+
+Procedure |unit_str_room| needs to be declared |forward| here because it calls
+|do_compaction| and |do_compaction| can call the error routines. Actually,
+|unit_str_room| avoids |overflow| errors but it can call |confusion|.
+
+@<Basic printing...@>=
+void mp_print_visible_char (MP mp, ASCII_code s) { /* prints a single character */
+ switch (mp->selector) {
+ case term_and_log:
+ wterm_chr(xchr(s)); wlog_chr(xchr(s));
+ incr(mp->term_offset); incr(mp->file_offset);
+ if ( mp->term_offset==(unsigned)mp->max_print_line ) {
+ wterm_cr; mp->term_offset=0;
+ };
+ if ( mp->file_offset==(unsigned)mp->max_print_line ) {
+ wlog_cr; mp->file_offset=0;
+ };
+ break;
+ case log_only:
+ wlog_chr(xchr(s)); incr(mp->file_offset);
+ if ( mp->file_offset==(unsigned)mp->max_print_line ) mp_print_ln(mp);
+ break;
+ case term_only:
+ wterm_chr(xchr(s)); incr(mp->term_offset);
+ if ( mp->term_offset==(unsigned)mp->max_print_line ) mp_print_ln(mp);
+ break;
+ case no_print:
+ break;
+ case pseudo:
+ if ( mp->tally<mp->trick_count )
+ mp->trick_buf[mp->tally % mp->error_line]=s;
+ break;
+ case new_string:
+ if (mp->pool_ptr>=mp->pool_size || mp->pool_ptr>=mp->max_pool_ptr ) {
+ mp_unit_str_room(mp);
+ if ( mp->pool_ptr>=mp->pool_size )
+ goto DONE; /* drop characters if string space is full */
+ };
+ append_char(s);
+ break;
+ default:
+ { text_char ss[2]; ss[0] = xchr(s); ss[1]=0;
+ do_fprintf(mp->wr_file[(mp->selector-write_file)],(char *)ss);
+ }
+ }
+DONE:
+ incr(mp->tally);
+}
+
+@ The |print_char| procedure sends one character to the desired destination.
+File names and string expressions might contain |ASCII_code| values that
+can't be printed using |print_visible_char|. These characters will be
+printed in three- or four-symbol form like `\.{\^\^A}' or `\.{\^\^e4}'.
+(This procedure assumes that it is safe to bypass all checks for unprintable
+characters when |selector| is in the range |0..max_write_files-1|.
+The user might want to write unprintable characters.
+
+@<Basic printing...@>=
+void mp_print_char (MP mp, ASCII_code k) { /* prints a single character */
+ if ( mp->selector<pseudo || mp->selector>=write_file) {
+ mp_print_visible_char(mp, k);
+ } else if ( @<Character |k| cannot be printed@> ) {
+ mp_print(mp, "^^");
+ if ( k<0100 ) {
+ mp_print_visible_char(mp, k+0100);
+ } else if ( k<0200 ) {
+ mp_print_visible_char(mp, k-0100);
+ } else {
+ int l; /* small index or counter */
+ l = (k / 16);
+ mp_print_visible_char(mp, xord(l<10 ? l+'0' : l-10+'a'));
+ l = (k % 16);
+ mp_print_visible_char(mp, xord(l<10 ? l+'0' : l-10+'a'));
+ }
+ } else {
+ mp_print_visible_char(mp, k);
+ }
+}
+
+@ An entire string is output by calling |print|. Note that if we are outputting
+the single standard ASCII character \.c, we could call |print("c")|, since
+|"c"=99| is the number of a single-character string, as explained above. But
+|print_char("c")| is quicker, so \MP\ goes directly to the |print_char|
+routine when it knows that this is safe. (The present implementation
+assumes that it is always safe to print a visible ASCII character.)
+@^system dependencies@>
+
+@<Basic print...@>=
+static void mp_do_print (MP mp, const char *ss, size_t len) { /* prints string |s| */
+ size_t j = 0;
+ if (mp->selector == new_string) {
+ str_room((integer)(len*4));
+ }
+ while ( j<len ){
+ /* this was |xord((int)ss[j])| but that doesnt work */
+ mp_print_char(mp, (ASCII_code)ss[j]); j++;
+ }
+}
+
+@
+@<Basic print...@>=
+void mp_print (MP mp, const char *ss) {
+ if (ss==NULL) return;
+ mp_do_print(mp, ss,strlen(ss));
+}
+void mp_print_str (MP mp, str_number s) {
+ pool_pointer j; /* current character code position */
+ if ( (s<0)||(s>mp->max_str_ptr) ) {
+ mp_do_print(mp,"???",3); /* this can't happen */
+@.???@>
+ }
+ j=mp->str_start[s];
+ mp_do_print(mp, (char *)(mp->str_pool+j), (size_t)(str_stop(s)-j));
+}
+
+
+@ Here is the very first thing that \MP\ prints: a headline that identifies
+the version number and base name. The |term_offset| variable is temporarily
+incorrect, but the discrepancy is not serious since we assume that the banner
+and mem identifier together will occupy at most |max_print_line|
+character positions.
+
+@<Initialize the output...@>=
+wterm (mp->banner);
+if (mp->mem_ident!=NULL)
+ mp_print(mp,mp->mem_ident);
+mp_print_ln(mp);
+update_terminal;
+
+@ The procedure |print_nl| is like |print|, but it makes sure that the
+string appears at the beginning of a new line.
+
+@<Basic print...@>=
+void mp_print_nl (MP mp, const char *s) { /* prints string |s| at beginning of line */
+ switch(mp->selector) {
+ case term_and_log:
+ if ( (mp->term_offset>0)||(mp->file_offset>0) ) mp_print_ln(mp);
+ break;
+ case log_only:
+ if ( mp->file_offset>0 ) mp_print_ln(mp);
+ break;
+ case term_only:
+ if ( mp->term_offset>0 ) mp_print_ln(mp);
+ break;
+ case no_print:
+ case pseudo:
+ case new_string:
+ break;
+ } /* there are no other cases */
+ mp_print(mp, s);
+}
+
+@ The following procedure, which prints out the decimal representation of a
+given integer |n|, assumes that all integers fit nicely into a |int|.
+@^system dependencies@>
+
+@<Basic print...@>=
+void mp_print_int (MP mp,integer n) { /* prints an integer in decimal form */
+ char s[12];
+ mp_snprintf(s,12,"%d", (int)n);
+ mp_print(mp,s);
+}
+
+@ @<Internal library ...@>=
+void mp_print_int (MP mp,integer n);
+
+@ \MP\ also makes use of a trivial procedure to print two digits. The
+following subroutine is usually called with a parameter in the range |0<=n<=99|.
+
+@c
+static void mp_print_dd (MP mp,integer n) { /* prints two least significant digits */
+ n=abs(n) % 100;
+ mp_print_char(mp, xord('0'+(n / 10)));
+ mp_print_char(mp, xord('0'+(n % 10)));
+}
+
+
+@ @<Declarations@>=
+static void mp_print_dd (MP mp,integer n);
+
+@ Here is a procedure that asks the user to type a line of input,
+assuming that the |selector| setting is either |term_only| or |term_and_log|.
+The input is placed into locations |first| through |last-1| of the
+|buffer| array, and echoed on the transcript file if appropriate.
+
+This procedure is never called when |interaction<mp_scroll_mode|.
+
+@d prompt_input(A) do {
+ if (!mp->noninteractive) {
+ wake_up_terminal; mp_print(mp, (A));
+ }
+ mp_term_input(mp);
+ } while (0) /* prints a string and gets a line of input */
+
+@c
+void mp_term_input (MP mp) { /* gets a line from the terminal */
+ size_t k; /* index into |buffer| */
+ if (mp->noninteractive) {
+ if (!mp_input_ln(mp, mp->term_in ))
+ longjmp(*(mp->jump_buf),1); /* chunk finished */
+ mp->buffer[mp->last]=xord('%');
+ } else {
+ update_terminal; /* Now the user sees the prompt for sure */
+ if (!mp_input_ln(mp, mp->term_in )) {
+ mp_fatal_error(mp, "End of file on the terminal!");
+@.End of file on the terminal@>
+ }
+ mp->term_offset=0; /* the user's line ended with \<\rm return> */
+ decr(mp->selector); /* prepare to echo the input */
+ if ( mp->last!=mp->first ) {
+ for (k=mp->first;k<mp->last;k++) {
+ mp_print_char(mp, mp->buffer[k]);
+ }
+ }
+ mp_print_ln(mp);
+ mp->buffer[mp->last]=xord('%');
+ incr(mp->selector); /* restore previous status */
+ }
+}
+
+@* \[6] Reporting errors.
+When something anomalous is detected, \MP\ typically does something like this:
+$$\vbox{\halign{#\hfil\cr
+|print_err("Something anomalous has been detected");|\cr
+|help3("This is the first line of my offer to help.")|\cr
+|("This is the second line. I'm trying to")|\cr
+|("explain the best way for you to proceed.");|\cr
+|error;|\cr}}$$
+A two-line help message would be given using |help2|, etc.; these informal
+helps should use simple vocabulary that complements the words used in the
+official error message that was printed. (Outside the U.S.A., the help
+messages should preferably be translated into the local vernacular. Each
+line of help is at most 60 characters long, in the present implementation,
+so that |max_print_line| will not be exceeded.)
+
+The |print_err| procedure supplies a `\.!' before the official message,
+and makes sure that the terminal is awake if a stop is going to occur.
+The |error| procedure supplies a `\..' after the official message, then it
+shows the location of the error; and if |interaction=error_stop_mode|,
+it also enters into a dialog with the user, during which time the help
+message may be printed.
+@^system dependencies@>
+
+@ The global variable |interaction| has four settings, representing increasing
+amounts of user interaction:
+
+@<Exported types@>=
+enum mp_interaction_mode {
+ mp_unspecified_mode=0, /* extra value for command-line switch */
+ mp_batch_mode, /* omits all stops and omits terminal output */
+ mp_nonstop_mode, /* omits all stops */
+ mp_scroll_mode, /* omits error stops */
+ mp_error_stop_mode /* stops at every opportunity to interact */
+};
+
+@ @<Option variables@>=
+int interaction; /* current level of interaction */
+int noninteractive; /* do we have a terminal? */
+
+@ Set it here so it can be overwritten by the commandline
+
+@<Allocate or initialize ...@>=
+mp->interaction=opt->interaction;
+if (mp->interaction==mp_unspecified_mode || mp->interaction>mp_error_stop_mode)
+ mp->interaction=mp_error_stop_mode;
+if (mp->interaction<mp_unspecified_mode)
+ mp->interaction=mp_batch_mode;
+
+@
+
+@d print_err(A) mp_print_err(mp,(A))
+
+@<Internal ...@>=
+void mp_print_err(MP mp, const char * A);
+
+@ @c
+void mp_print_err(MP mp, const char * A) {
+ if ( mp->interaction==mp_error_stop_mode )
+ wake_up_terminal;
+ if (mp->file_line_error_style && file_state && !terminal_input) {
+ mp_print_nl(mp, "");
+ if (mp->long_name != NULL) {
+ mp_print(mp, mp->long_name);
+ } else {
+ mp_print(mp, mp_str(mp,name));
+ }
+ mp_print(mp, ":");
+ mp_print_int(mp, line);
+ mp_print(mp, ": ");
+ } else{
+ mp_print_nl(mp, "! ");
+ }
+ mp_print(mp, A);
+@.!\relax@>
+}
+
+
+@ \MP\ is careful not to call |error| when the print |selector| setting
+might be unusual. The only possible values of |selector| at the time of
+error messages are
+
+\yskip\hang|no_print| (when |interaction=mp_batch_mode|
+ and |log_file| not yet open);
+
+\hang|term_only| (when |interaction>mp_batch_mode| and |log_file| not yet open);
+
+\hang|log_only| (when |interaction=mp_batch_mode| and |log_file| is open);
+
+\hang|term_and_log| (when |interaction>mp_batch_mode| and |log_file| is open).
+
+@<Initialize the print |selector| based on |interaction|@>=
+if ( mp->interaction==mp_batch_mode ) mp->selector=no_print; else mp->selector=term_only
+
+@ A global variable |deletions_allowed| is set |false| if the |get_next|
+routine is active when |error| is called; this ensures that |get_next|
+will never be called recursively.
+@^recursion@>
+
+The global variable |history| records the worst level of error that
+has been detected. It has four possible values: |spotless|, |warning_issued|,
+|error_message_issued|, and |fatal_error_stop|.
+
+Another global variable, |error_count|, is increased by one when an
+|error| occurs without an interactive dialog, and it is reset to zero at
+the end of every statement. If |error_count| reaches 100, \MP\ decides
+that there is no point in continuing further.
+
+@<Exported types@>=
+enum mp_history_state {
+ mp_spotless=0, /* |history| value when nothing has been amiss yet */
+ mp_warning_issued, /* |history| value when |begin_diagnostic| has been called */
+ mp_error_message_issued, /* |history| value when |error| has been called */
+ mp_fatal_error_stop, /* |history| value when termination was premature */
+ mp_system_error_stop /* |history| value when termination was due to disaster */
+};
+
+@ @<Glob...@>=
+boolean deletions_allowed; /* is it safe for |error| to call |get_next|? */
+int history; /* has the source input been clean so far? */
+int error_count; /* the number of scrolled errors since the last statement ended */
+
+@ The value of |history| is initially |fatal_error_stop|, but it will
+be changed to |spotless| if \MP\ survives the initialization process.
+
+@<Allocate or ...@>=
+mp->deletions_allowed=true; /* |history| is initialized elsewhere */
+
+@ Since errors can be detected almost anywhere in \MP, we want to declare the
+error procedures near the beginning of the program. But the error procedures
+in turn use some other procedures, which need to be declared |forward|
+before we get to |error| itself.
+
+It is possible for |error| to be called recursively if some error arises
+when |get_next| is being used to delete a token, and/or if some fatal error
+occurs while \MP\ is trying to fix a non-fatal one. But such recursion
+@^recursion@>
+is never more than two levels deep.
+
+@<Declarations@>=
+static void mp_get_next (MP mp);
+static void mp_term_input (MP mp);
+static void mp_show_context (MP mp);
+static void mp_begin_file_reading (MP mp);
+static void mp_open_log_file (MP mp);
+static void mp_clear_for_error_prompt (MP mp);
+
+@ @<Internal ...@>=
+void mp_normalize_selector (MP mp);
+
+@ Individual lines of help are recorded in the array |help_line|, which
+contains entries in positions |0..(help_ptr-1)|. They should be printed
+in reverse order, i.e., with |help_line[0]| appearing last.
+
+@d hlp1(A) mp->help_line[0]=A; }
+@d hlp2(A,B) mp->help_line[1]=A; hlp1(B)
+@d hlp3(A,B,C) mp->help_line[2]=A; hlp2(B,C)
+@d hlp4(A,B,C,D) mp->help_line[3]=A; hlp3(B,C,D)
+@d hlp5(A,B,C,D,E) mp->help_line[4]=A; hlp4(B,C,D,E)
+@d hlp6(A,B,C,D,E,F) mp->help_line[5]=A; hlp5(B,C,D,E,F)
+@d help0 mp->help_ptr=0 /* sometimes there might be no help */
+@d help1 { mp->help_ptr=1; hlp1 /* use this with one help line */
+@d help2 { mp->help_ptr=2; hlp2 /* use this with two help lines */
+@d help3 { mp->help_ptr=3; hlp3 /* use this with three help lines */
+@d help4 { mp->help_ptr=4; hlp4 /* use this with four help lines */
+@d help5 { mp->help_ptr=5; hlp5 /* use this with five help lines */
+@d help6 { mp->help_ptr=6; hlp6 /* use this with six help lines */
+
+@<Glob...@>=
+const char * help_line[6]; /* helps for the next |error| */
+unsigned int help_ptr; /* the number of help lines present */
+boolean use_err_help; /* should the |err_help| string be shown? */
+str_number err_help; /* a string set up by \&{errhelp} */
+
+@ @<Allocate or ...@>=
+mp->use_err_help=false;
+
+@ The |jump_out| procedure just cuts across all active procedure levels and
+goes to |end_of_MP|. This is the only nonlocal |goto| statement in the
+whole program. It is used when there is no recovery from a particular error.
+
+The program uses a |jump_buf| to handle this, this is initialized at three
+spots: the start of |mp_new|, the start of |mp_initialize|, and the start
+of |mp_run|. Those are the only library enty points.
+
+@^system dependencies@>
+
+@<Glob...@>=
+jmp_buf *jump_buf;
+
+@ If the array of internals is still |NULL| when |jump_out| is called, a
+crash occured during initialization, and it is not safe to run the normal
+cleanup routine.
+
+@<Error hand...@>=
+static void mp_jump_out (MP mp) {
+ if (mp->internal!=NULL && mp->history < mp_system_error_stop)
+ mp_close_files_and_terminate(mp);
+ longjmp(*(mp->jump_buf),1);
+}
+
+@ Here now is the general |error| routine.
+
+@<Error hand...@>=
+void mp_error (MP mp) { /* completes the job of error reporting */
+ ASCII_code c; /* what the user types */
+ integer s1,s2,s3; /* used to save global variables when deleting tokens */
+ pool_pointer j; /* character position being printed */
+ if ( mp->history<mp_error_message_issued )
+ mp->history=mp_error_message_issued;
+ mp_print_char(mp, xord('.')); mp_show_context(mp);
+ if (mp->halt_on_error) {
+ mp->history=mp_fatal_error_stop; mp_jump_out(mp);
+ }
+ if ((!mp->noninteractive) && (mp->interaction==mp_error_stop_mode )) {
+ @<Get user's advice and |return|@>;
+ }
+ incr(mp->error_count);
+ if ( mp->error_count==100 ) {
+ mp_print_nl(mp,"(That makes 100 errors; please try again.)");
+@.That makes 100 errors...@>
+ mp->history=mp_fatal_error_stop; mp_jump_out(mp);
+ }
+ @<Put help message on the transcript file@>;
+}
+void mp_warn (MP mp, const char *msg) {
+ unsigned saved_selector = mp->selector;
+ mp_normalize_selector(mp);
+ mp_print_nl(mp,"Warning: ");
+ mp_print(mp,msg);
+ mp_print_ln(mp);
+ mp->selector = saved_selector;
+}
+
+@ @<Exported function ...@>=
+extern void mp_error (MP mp);
+extern void mp_warn (MP mp, const char *msg);
+
+
+@ @<Get user's advice...@>=
+while (true) {
+CONTINUE:
+ mp_clear_for_error_prompt(mp); prompt_input("? ");
+@.?\relax@>
+ if ( mp->last==mp->first ) return;
+ c=mp->buffer[mp->first];
+ if ( c>='a' ) c=c+'A'-'a'; /* convert to uppercase */
+ @<Interpret code |c| and |return| if done@>;
+}
+
+@ It is desirable to provide an `\.E' option here that gives the user
+an easy way to return from \MP\ to the system editor, with the offending
+line ready to be edited. But such an extension requires some system
+wizardry, so the present implementation simply types out the name of the
+file that should be
+edited and the relevant line number.
+@^system dependencies@>
+
+@<Exported types@>=
+typedef void (*mp_editor_cmd)(MP, char *, int);
+
+@ @<Option variables@>=
+mp_editor_cmd run_editor;
+
+@ @<Allocate or initialize ...@>=
+set_callback_option(run_editor);
+
+@ @<Declarations@>=
+static void mp_run_editor (MP mp, char *fname, int fline);
+
+@ @c
+void mp_run_editor (MP mp, char *fname, int fline) {
+ char *s = xmalloc(256,1);
+ mp_snprintf(s, 256,"You want to edit file %s at line %d\n", fname, fline);
+ wterm_ln(s);
+@.You want to edit file x@>
+}
+
+@
+There is a secret `\.D' option available when the debugging routines haven't
+been commented~out.
+@^debugging@>
+
+@<Interpret code |c| and |return| if done@>=
+switch (c) {
+case '0': case '1': case '2': case '3': case '4':
+case '5': case '6': case '7': case '8': case '9':
+ if ( mp->deletions_allowed ) {
+ @<Delete |c-"0"| tokens and |continue|@>;
+ }
+ break;
+case 'E':
+ if ( mp->file_ptr>0 ){
+ mp->interaction=mp_scroll_mode;
+ mp_close_files_and_terminate(mp);
+ (mp->run_editor)(mp,
+ str(mp->input_stack[mp->file_ptr].name_field),
+ mp_true_line(mp));
+ mp_jump_out(mp);
+ }
+ break;
+case 'H':
+ @<Print the help information and |continue|@>;
+ /* |break;| */
+case 'I':
+ @<Introduce new material from the terminal and |return|@>;
+ /* |break;| */
+case 'Q': case 'R': case 'S':
+ @<Change the interaction level and |return|@>;
+ /* |break;| */
+case 'X':
+ mp->interaction=mp_scroll_mode; mp_jump_out(mp);
+ break;
+default:
+ break;
+}
+@<Print the menu of available options@>
+
+@ @<Print the menu...@>=
+{
+ mp_print(mp, "Type <return> to proceed, S to scroll future error messages,");
+@.Type <return> to proceed...@>
+ mp_print_nl(mp, "R to run without stopping, Q to run quietly,");
+ mp_print_nl(mp, "I to insert something, ");
+ if ( mp->file_ptr>0 )
+ mp_print(mp, "E to edit your file,");
+ if ( mp->deletions_allowed )
+ mp_print_nl(mp, "1 or ... or 9 to ignore the next 1 to 9 tokens of input,");
+ mp_print_nl(mp, "H for help, X to quit.");
+}
+
+@ Here the author of \MP\ apologizes for making use of the numerical
+relation between |"Q"|, |"R"|, |"S"|, and the desired interaction settings
+|mp_batch_mode|, |mp_nonstop_mode|, |mp_scroll_mode|.
+@^Knuth, Donald Ervin@>
+
+@<Change the interaction...@>=
+{
+ mp->error_count=0; mp->interaction=mp_batch_mode+c-'Q';
+ mp_print(mp, "OK, entering ");
+ switch (c) {
+ case 'Q': mp_print(mp, "batchmode"); decr(mp->selector); break;
+ case 'R': mp_print(mp, "nonstopmode"); break;
+ case 'S': mp_print(mp, "scrollmode"); break;
+ } /* there are no other cases */
+ mp_print(mp, "..."); mp_print_ln(mp); update_terminal; return;
+}
+
+@ When the following code is executed, |buffer[(first+1)..(last-1)]| may
+contain the material inserted by the user; otherwise another prompt will
+be given. In order to understand this part of the program fully, you need
+to be familiar with \MP's input stacks.
+
+@<Introduce new material...@>=
+{
+ mp_begin_file_reading(mp); /* enter a new syntactic level for terminal input */
+ if ( mp->last>mp->first+1 ) {
+ loc=(halfword)(mp->first+1); mp->buffer[mp->first]=xord(' ');
+ } else {
+ prompt_input("insert>"); loc=(halfword)mp->first;
+@.insert>@>
+ };
+ mp->first=mp->last+1; mp->cur_input.limit_field=(halfword)mp->last; return;
+}
+
+@ We allow deletion of up to 99 tokens at a time.
+
+@<Delete |c-"0"| tokens...@>=
+{
+ s1=mp->cur_cmd; s2=mp->cur_mod; s3=mp->cur_sym; mp->OK_to_interrupt=false;
+ if ( (mp->last>mp->first+1) && (mp->buffer[mp->first+1]>='0')&&(mp->buffer[mp->first+1]<='9') )
+ c=xord(c*10+mp->buffer[mp->first+1]-'0'*11);
+ else
+ c=c-'0';
+ while ( c>0 ) {
+ mp_get_next(mp); /* one-level recursive call of |error| is possible */
+ @<Decrease the string reference count, if the current token is a string@>;
+ decr(c);
+ };
+ mp->cur_cmd=s1; mp->cur_mod=s2; mp->cur_sym=s3; mp->OK_to_interrupt=true;
+ help2("I have just deleted some text, as you asked.",
+ "You can now delete more, or insert, or whatever.");
+ mp_show_context(mp);
+ goto CONTINUE;
+}
+
+@ @<Print the help info...@>=
+{
+ if ( mp->use_err_help ) {
+ @<Print the string |err_help|, possibly on several lines@>;
+ mp->use_err_help=false;
+ } else {
+ if ( mp->help_ptr==0 ) {
+ help2("Sorry, I don't know how to help in this situation.",
+ "Maybe you should try asking a human?");
+ }
+ do {
+ decr(mp->help_ptr); mp_print(mp, mp->help_line[mp->help_ptr]); mp_print_ln(mp);
+ } while (mp->help_ptr!=0);
+ };
+ help4("Sorry, I already gave what help I could...",
+ "Maybe you should try asking a human?",
+ "An error might have occurred before I noticed any problems.",
+ "``If all else fails, read the instructions.''");
+ goto CONTINUE;
+}
+
+@ @<Print the string |err_help|, possibly on several lines@>=
+j=mp->str_start[mp->err_help];
+while ( j<str_stop(mp->err_help) ) {
+ if ( mp->str_pool[j]!='%' ) mp_print_str(mp, mp->str_pool[j]);
+ else if ( j+1==str_stop(mp->err_help) ) mp_print_ln(mp);
+ else if ( mp->str_pool[j+1]!='%' ) mp_print_ln(mp);
+ else { j++; mp_print_char(mp, xord('%')); };
+ j++;
+}
+
+@ @<Put help message on the transcript file@>=
+if ( mp->interaction>mp_batch_mode ) decr(mp->selector); /* avoid terminal output */
+if ( mp->use_err_help ) {
+ mp_print_nl(mp, "");
+ @<Print the string |err_help|, possibly on several lines@>;
+} else {
+ while ( mp->help_ptr>0 ){
+ decr(mp->help_ptr); mp_print_nl(mp, mp->help_line[mp->help_ptr]);
+ };
+}
+mp_print_ln(mp);
+if ( mp->interaction>mp_batch_mode ) incr(mp->selector); /* re-enable terminal output */
+mp_print_ln(mp)
+
+@ In anomalous cases, the print selector might be in an unknown state;
+the following subroutine is called to fix things just enough to keep
+running a bit longer.
+
+@c
+void mp_normalize_selector (MP mp) {
+ if ( mp->log_opened ) mp->selector=term_and_log;
+ else mp->selector=term_only;
+ if ( mp->job_name==NULL) mp_open_log_file(mp);
+ if ( mp->interaction==mp_batch_mode ) decr(mp->selector);
+}
+
+@ The following procedure prints \MP's last words before dying.
+
+@d succumb { if ( mp->interaction==mp_error_stop_mode )
+ mp->interaction=mp_scroll_mode; /* no more interaction */
+ if ( mp->log_opened ) mp_error(mp);
+ mp->history=mp_fatal_error_stop; mp_jump_out(mp); /* irrecoverable error */
+ }
+
+@<Error hand...@>=
+void mp_fatal_error (MP mp, const char *s) { /* prints |s|, and that's it */
+ mp_normalize_selector(mp);
+ print_err("Emergency stop"); help1(s); succumb;
+@.Emergency stop@>
+}
+
+@ @<Exported function ...@>=
+extern void mp_fatal_error (MP mp, const char *s);
+
+
+@ Here is the most dreaded error message.
+
+@<Error hand...@>=
+void mp_overflow (MP mp, const char *s, integer n) { /* stop due to finiteness */
+ char msg[256];
+ mp_normalize_selector(mp);
+ mp_snprintf(msg, 256, "MetaPost capacity exceeded, sorry [%s=%d]",s,(int)n);
+@.MetaPost capacity exceeded ...@>
+ print_err(msg);
+ help2("If you really absolutely need more capacity,",
+ "you can ask a wizard to enlarge me.");
+ succumb;
+}
+
+@ @<Internal library declarations@>=
+void mp_overflow (MP mp, const char *s, integer n);
+
+@ The program might sometime run completely amok, at which point there is
+no choice but to stop. If no previous error has been detected, that's bad
+news; a message is printed that is really intended for the \MP\
+maintenance person instead of the user (unless the user has been
+particularly diabolical). The index entries for `this can't happen' may
+help to pinpoint the problem.
+@^dry rot@>
+
+@<Internal library ...@>=
+void mp_confusion (MP mp, const char *s);
+
+@ Consistency check violated; |s| tells where.
+@<Error hand...@>=
+void mp_confusion (MP mp, const char *s) {
+ char msg[256];
+ mp_normalize_selector(mp);
+ if ( mp->history<mp_error_message_issued ) {
+ mp_snprintf(msg, 256, "This can't happen (%s)",s);
+@.This can't happen@>
+ print_err(msg);
+ help1("I'm broken. Please show this to someone who can fix can fix");
+ } else {
+ print_err("I can\'t go on meeting you like this");
+@.I can't go on...@>
+ help2("One of your faux pas seems to have wounded me deeply...",
+ "in fact, I'm barely conscious. Please fix it and try again.");
+ }
+ succumb;
+}
+
+@ Users occasionally want to interrupt \MP\ while it's running.
+If the runtime system allows this, one can implement
+a routine that sets the global variable |interrupt| to some nonzero value
+when such an interrupt is signaled. Otherwise there is probably at least
+a way to make |interrupt| nonzero using the C debugger.
+@^system dependencies@>
+@^debugging@>
+
+@d check_interrupt { if ( mp->interrupt!=0 )
+ mp_pause_for_instructions(mp); }
+
+@<Global...@>=
+integer interrupt; /* should \MP\ pause for instructions? */
+boolean OK_to_interrupt; /* should interrupts be observed? */
+integer run_state; /* are we processing input ?*/
+boolean finished; /* set true by |close_files_and_terminate| */
+
+@ @<Allocate or ...@>=
+mp->OK_to_interrupt=true;
+mp->finished=false;
+
+@ When an interrupt has been detected, the program goes into its
+highest interaction level and lets the user have the full flexibility of
+the |error| routine. \MP\ checks for interrupts only at times when it is
+safe to do this.
+
+@c
+static void mp_pause_for_instructions (MP mp) {
+ if ( mp->OK_to_interrupt ) {
+ mp->interaction=mp_error_stop_mode;
+ if ( (mp->selector==log_only)||(mp->selector==no_print) )
+ incr(mp->selector);
+ print_err("Interruption");
+@.Interruption@>
+ help3("You rang?",
+ "Try to insert some instructions for me (e.g.,`I show x'),",
+ "unless you just want to quit by typing `X'.");
+ mp->deletions_allowed=false; mp_error(mp); mp->deletions_allowed=true;
+ mp->interrupt=0;
+ }
+}
+
+@ Many of \MP's error messages state that a missing token has been
+inserted behind the scenes. We can save string space and program space
+by putting this common code into a subroutine.
+
+@c
+static void mp_missing_err (MP mp, const char *s) {
+ char msg[256];
+ mp_snprintf(msg, 256, "Missing `%s' has been inserted", s);
+@.Missing...inserted@>
+ print_err(msg);
+}
+
+@* \[7] Arithmetic with scaled numbers.
+The principal computations performed by \MP\ are done entirely in terms of
+integers less than $2^{31}$ in magnitude; thus, the arithmetic specified in this
+program can be carried out in exactly the same way on a wide variety of
+computers, including some small ones.
+@^small computers@>
+
+But C does not rigidly define the |/| operation in the case of negative
+dividends; for example, the result of |(-2*n-1) / 2| is |-(n+1)| on some
+computers and |-n| on others (is this true ?). There are two principal
+types of arithmetic: ``translation-preserving,'' in which the identity
+|(a+q*b)/b=(a/b)+q| is valid; and ``negation-preserving,'' in which
+|(-a)/b=-(a/b)|. This leads to two \MP s, which can produce
+different results, although the differences should be negligible when the
+language is being used properly. The \TeX\ processor has been defined
+carefully so that both varieties of arithmetic will produce identical
+output, but it would be too inefficient to constrain \MP\ in a similar way.
+
+@d el_gordo 0x7fffffff /* $2^{31}-1$, the largest value that \MP\ likes */
+
+
+@ One of \MP's most common operations is the calculation of
+$\lfloor{a+b\over2}\rfloor$,
+the midpoint of two given integers |a| and~|b|. The most decent way to do
+this is to write `|(a+b)/2|'; but on many machines it is more efficient
+to calculate `|(a+b)>>1|'.
+
+Therefore the midpoint operation will always be denoted by `|half(a+b)|'
+in this program. If \MP\ is being implemented with languages that permit
+binary shifting, the |half| macro should be changed to make this operation
+as efficient as possible. Since some systems have shift operators that can
+only be trusted to work on positive numbers, there is also a macro |halfp|
+that is used only when the quantity being halved is known to be positive
+or zero.
+
+@d half(A) ((A) / 2)
+@d halfp(A) (integer)((unsigned)(A) >> 1)
+
+@ A single computation might use several subroutine calls, and it is
+desirable to avoid producing multiple error messages in case of arithmetic
+overflow. So the routines below set the global variable |arith_error| to |true|
+instead of reporting errors directly to the user.
+@^overflow in arithmetic@>
+
+@<Glob...@>=
+boolean arith_error; /* has arithmetic overflow occurred recently? */
+
+@ @<Allocate or ...@>=
+mp->arith_error=false;
+
+@ At crucial points the program will say |check_arith|, to test if
+an arithmetic error has been detected.
+
+@d check_arith { if ( mp->arith_error ) mp_clear_arith(mp); }
+
+@c
+static void mp_clear_arith (MP mp) {
+ print_err("Arithmetic overflow");
+@.Arithmetic overflow@>
+ help4("Uh, oh. A little while ago one of the quantities that I was",
+ "computing got too large, so I'm afraid your answers will be",
+ "somewhat askew. You'll probably have to adopt different",
+ "tactics next time. But I shall try to carry on anyway.");
+ mp_error(mp);
+ mp->arith_error=false;
+}
+
+@ Addition is not always checked to make sure that it doesn't overflow,
+but in places where overflow isn't too unlikely the |slow_add| routine
+is used.
+
+@c static integer mp_slow_add (MP mp,integer x, integer y) {
+ if ( x>=0 ) {
+ if ( y<=el_gordo-x ) {
+ return x+y;
+ } else {
+ mp->arith_error=true;
+ return el_gordo;
+ }
+ } else if ( -y<=el_gordo+x ) {
+ return x+y;
+ } else {
+ mp->arith_error=true;
+ return -el_gordo;
+ }
+}
+
+@ Fixed-point arithmetic is done on {\sl scaled integers\/} that are multiples
+of $2^{-16}$. In other words, a binary point is assumed to be sixteen bit
+positions from the right end of a binary computer word.
+
+@d quarter_unit 040000 /* $2^{14}$, represents 0.250000 */
+@d half_unit 0100000 /* $2^{15}$, represents 0.50000 */
+@d three_quarter_unit 0140000 /* $3\cdot2^{14}$, represents 0.75000 */
+@d unity 0200000 /* $2^{16}$, represents 1.00000 */
+@d two 0400000 /* $2^{17}$, represents 2.00000 */
+@d three 0600000 /* $2^{17}+2^{16}$, represents 3.00000 */
+
+@<Types...@>=
+typedef integer scaled; /* this type is used for scaled integers */
+
+@ The following function is used to create a scaled integer from a given decimal
+fraction $(.d_0d_1\ldots d_{k-1})$, where |0<=k<=17|. The digit $d_i$ is
+given in |dig[i]|, and the calculation produces a correctly rounded result.
+
+@c
+static scaled mp_round_decimals (MP mp,quarterword k) {
+ /* converts a decimal fraction */
+ unsigned a = 0; /* the accumulator */
+ while ( k-->0 ) {
+ a=(a+mp->dig[k]*two) / 10;
+ }
+ return (scaled)halfp(a+1);
+}
+
+@ Conversely, here is a procedure analogous to |print_int|. If the output
+of this procedure is subsequently read by \MP\ and converted by the
+|round_decimals| routine above, it turns out that the original value will
+be reproduced exactly. A decimal point is printed only if the value is
+not an integer. If there is more than one way to print the result with
+the optimum number of digits following the decimal point, the closest
+possible value is given.
+
+The invariant relation in the \&{repeat} loop is that a sequence of
+decimal digits yet to be printed will yield the original number if and only if
+they form a fraction~$f$ in the range $s-\delta\L10\cdot2^{16}f<s$.
+We can stop if and only if $f=0$ satisfies this condition; the loop will
+terminate before $s$ can possibly become zero.
+
+@<Basic printing...@>=
+void mp_print_scaled (MP mp,scaled s) { /* prints scaled real, rounded to five digits */
+ scaled delta; /* amount of allowable inaccuracy */
+ if ( s<0 ) {
+ mp_print_char(mp, xord('-'));
+ negate(s); /* print the sign, if negative */
+ }
+ mp_print_int(mp, s / unity); /* print the integer part */
+ s=10*(s % unity)+5;
+ if ( s!=5 ) {
+ delta=10;
+ mp_print_char(mp, xord('.'));
+ do {
+ if ( delta>unity )
+ s=s+0100000-(delta / 2); /* round the final digit */
+ mp_print_char(mp, xord('0'+(s / unity)));
+ s=10*(s % unity);
+ delta=delta*10;
+ } while (s>delta);
+ }
+}
+
+@ We often want to print two scaled quantities in parentheses,
+separated by a comma.
+
+@<Basic printing...@>=
+void mp_print_two (MP mp,scaled x, scaled y) { /* prints `|(x,y)|' */
+ mp_print_char(mp, xord('('));
+ mp_print_scaled(mp, x);
+ mp_print_char(mp, xord(','));
+ mp_print_scaled(mp, y);
+ mp_print_char(mp, xord(')'));
+}
+
+@ The |scaled| quantities in \MP\ programs are generally supposed to be
+less than $2^{12}$ in absolute value, so \MP\ does much of its internal
+arithmetic with 28~significant bits of precision. A |fraction| denotes
+a scaled integer whose binary point is assumed to be 28 bit positions
+from the right.
+
+@d fraction_half 01000000000 /* $2^{27}$, represents 0.50000000 */
+@d fraction_one 02000000000 /* $2^{28}$, represents 1.00000000 */
+@d fraction_two 04000000000 /* $2^{29}$, represents 2.00000000 */
+@d fraction_three 06000000000 /* $3\cdot2^{28}$, represents 3.00000000 */
+@d fraction_four 010000000000 /* $2^{30}$, represents 4.00000000 */
+
+@<Types...@>=
+typedef integer fraction; /* this type is used for scaled fractions */
+
+@ In fact, the two sorts of scaling discussed above aren't quite
+sufficient; \MP\ has yet another, used internally to keep track of angles
+in units of $2^{-20}$ degrees.
+
+@d forty_five_deg 0264000000 /* $45\cdot2^{20}$, represents $45^\circ$ */
+@d ninety_deg 0550000000 /* $90\cdot2^{20}$, represents $90^\circ$ */
+@d one_eighty_deg 01320000000 /* $180\cdot2^{20}$, represents $180^\circ$ */
+@d three_sixty_deg 02640000000 /* $360\cdot2^{20}$, represents $360^\circ$ */
+
+@<Types...@>=
+typedef integer angle; /* this type is used for scaled angles */
+
+@ The |make_fraction| routine produces the |fraction| equivalent of
+|p/q|, given integers |p| and~|q|; it computes the integer
+$f=\lfloor2^{28}p/q+{1\over2}\rfloor$, when $p$ and $q$ are
+positive. If |p| and |q| are both of the same scaled type |t|,
+the ``type relation'' |make_fraction(t,t)=fraction| is valid;
+and it's also possible to use the subroutine ``backwards,'' using
+the relation |make_fraction(t,fraction)=t| between scaled types.
+
+If the result would have magnitude $2^{31}$ or more, |make_fraction|
+sets |arith_error:=true|. Most of \MP's internal computations have
+been designed to avoid this sort of error.
+
+If this subroutine were programmed in assembly language on a typical
+machine, we could simply compute |(@t$2^{28}$@>*p)div q|, since a
+double-precision product can often be input to a fixed-point division
+instruction. But when we are restricted to int-eger arithmetic it
+is necessary either to resort to multiple-precision maneuvering
+or to use a simple but slow iteration. The multiple-precision technique
+would be about three times faster than the code adopted here, but it
+would be comparatively long and tricky, involving about sixteen
+additional multiplications and divisions.
+
+This operation is part of \MP's ``inner loop''; indeed, it will
+consume nearly 10\pct! of the running time (exclusive of input and output)
+if the code below is left unchanged. A machine-dependent recoding
+will therefore make \MP\ run faster. The present implementation
+is highly portable, but slow; it avoids multiplication and division
+except in the initial stage. System wizards should be careful to
+replace it with a routine that is guaranteed to produce identical
+results in all cases.
+@^system dependencies@>
+
+As noted below, a few more routines should also be replaced by machine-dependent
+code, for efficiency. But when a procedure is not part of the ``inner loop,''
+such changes aren't advisable; simplicity and robustness are
+preferable to trickery, unless the cost is too high.
+@^inner loop@>
+
+@<Internal library declarations@>=
+integer mp_take_scaled (MP mp,integer q, scaled f) ;
+
+@ @<Declarations@>=
+static fraction mp_make_fraction (MP mp,integer p, integer q);
+
+@ If FIXPT is not defined, we need these preprocessor values
+
+@d TWEXP31 2147483648.0
+@d TWEXP28 268435456.0
+@d TWEXP16 65536.0
+@d TWEXP_16 (1.0/65536.0)
+@d TWEXP_28 (1.0/268435456.0)
+
+
+@c
+fraction mp_make_fraction (MP mp,integer p, integer q) {
+ fraction i;
+ if ( q==0 ) mp_confusion(mp, "/");
+@:this can't happen /}{\quad \./@>
+#ifdef FIXPT
+{
+ integer f; /* the fraction bits, with a leading 1 bit */
+ integer n; /* the integer part of $\vert p/q\vert$ */
+ boolean negative = false; /* should the result be negated? */
+ if ( p<0 ) {
+ negate(p); negative=true;
+ }
+ if ( q<0 ) {
+ negate(q); negative = ! negative;
+ }
+ n=p / q; p=p % q;
+ if ( n>=8 ){
+ mp->arith_error=true;
+ i= ( negative ? -el_gordo : el_gordo);
+ } else {
+ n=(n-1)*fraction_one;
+ @<Compute $f=\lfloor 2^{28}(1+p/q)+{1\over2}\rfloor$@>;
+ i = (negative ? (-(f+n)) : (f+n));
+ }
+}
+#else /* FIXPT */
+ {
+ register double d;
+ d = TWEXP28 * (double)p /(double)q;
+ if ((p^q) >= 0) {
+ d += 0.5;
+ if (d>=TWEXP31) {mp->arith_error=true; return el_gordo;}
+ i = (integer) d;
+ if (d==(double)i && ( ((q>0 ? -q : q)&077777)
+ * (((i&037777)<<1)-1) & 04000)!=0) --i;
+ } else {
+ d -= 0.5;
+ if (d<= -TWEXP31) {mp->arith_error=true; return -el_gordo;}
+ i = (integer) d;
+ if (d==(double)i && ( ((q>0 ? q : -q)&077777)
+ * (((i&037777)<<1)+1) & 04000)!=0) ++i;
+ }
+ }
+#endif /* FIXPT */
+ return i;
+}
+
+@ The |repeat| loop here preserves the following invariant relations
+between |f|, |p|, and~|q|:
+(i)~|0<=p<q|; (ii)~$fq+p=2^k(q+p_0)$, where $k$ is an integer and
+$p_0$ is the original value of~$p$.
+
+Notice that the computation specifies
+|(p-q)+p| instead of |(p+p)-q|, because the latter could overflow.
+Let us hope that optimizing compilers do not miss this point; a
+special variable |be_careful| is used to emphasize the necessary
+order of computation. Optimizing compilers should keep |be_careful|
+in a register, not store it in memory.
+@^inner loop@>
+
+@<Compute $f=\lfloor 2^{28}(1+p/q)+{1\over2}\rfloor$@>=
+{
+ integer be_careful; /* disables certain compiler optimizations */
+ f=1;
+ do {
+ be_careful=p-q; p=be_careful+p;
+ if ( p>=0 ) {
+ f=f+f+1;
+ } else {
+ f+=f; p=p+q;
+ }
+ } while (f<fraction_one);
+ be_careful=p-q;
+ if ( be_careful+p>=0 ) incr(f);
+}
+
+@ The dual of |make_fraction| is |take_fraction|, which multiplies a
+given integer~|q| by a fraction~|f|. When the operands are positive, it
+computes $p=\lfloor qf/2^{28}+{1\over2}\rfloor$, a symmetric function
+of |q| and~|f|.
+
+This routine is even more ``inner loopy'' than |make_fraction|;
+the present implementation consumes almost 20\pct! of \MP's computation
+time during typical jobs, so a machine-language substitute is advisable.
+@^inner loop@> @^system dependencies@>
+
+@<Internal library declarations@>=
+integer mp_take_fraction (MP mp,integer q, fraction f) ;
+
+@ @c
+#ifdef FIXPT
+integer mp_take_fraction (MP mp,integer q, fraction f) {
+ integer p; /* the fraction so far */
+ boolean negative; /* should the result be negated? */
+ integer n; /* additional multiple of $q$ */
+ integer be_careful; /* disables certain compiler optimizations */
+ @<Reduce to the case that |f>=0| and |q>=0|@>;
+ if ( f<fraction_one ) {
+ n=0;
+ } else {
+ n=f / fraction_one; f=f % fraction_one;
+ if ( q<=el_gordo / n ) {
+ n=n*q ;
+ } else {
+ mp->arith_error=true; n=el_gordo;
+ }
+ }
+ f=f+fraction_one;
+ @<Compute $p=\lfloor qf/2^{28}+{1\over2}\rfloor-q$@>;
+ be_careful=n-el_gordo;
+ if ( be_careful+p>0 ){
+ mp->arith_error=true; n=el_gordo-p;
+ }
+ if ( negative )
+ return (-(n+p));
+ else
+ return (n+p);
+#else /* FIXPT */
+integer mp_take_fraction (MP mp,integer p, fraction q) {
+ register double d;
+ register integer i;
+ d = (double)p * (double)q * TWEXP_28;
+ if ((p^q) >= 0) {
+ d += 0.5;
+ if (d>=TWEXP31) {
+ if (d!=TWEXP31 || (((p&077777)*(q&077777))&040000)==0)
+ mp->arith_error = true;
+ return el_gordo;
+ }
+ i = (integer) d;
+ if (d==(double)i && (((p&077777)*(q&077777))&040000)!=0) --i;
+ } else {
+ d -= 0.5;
+ if (d<= -TWEXP31) {
+ if (d!= -TWEXP31 || ((-(p&077777)*(q&077777))&040000)==0)
+ mp->arith_error = true;
+ return -el_gordo;
+ }
+ i = (integer) d;
+ if (d==(double)i && ((-(p&077777)*(q&077777))&040000)!=0) ++i;
+ }
+ return i;
+#endif /* FIXPT */
+}
+
+@ @<Reduce to the case that |f>=0| and |q>=0|@>=
+if ( f>=0 ) {
+ negative=false;
+} else {
+ negate( f); negative=true;
+}
+if ( q<0 ) {
+ negate(q); negative=! negative;
+}
+
+@ The invariant relations in this case are (i)~$\lfloor(qf+p)/2^k\rfloor
+=\lfloor qf_0/2^{28}+{1\over2}\rfloor$, where $k$ is an integer and
+$f_0$ is the original value of~$f$; (ii)~$2^k\L f<2^{k+1}$.
+@^inner loop@>
+
+@<Compute $p=\lfloor qf/2^{28}+{1\over2}\rfloor-q$@>=
+p=fraction_half; /* that's $2^{27}$; the invariants hold now with $k=28$ */
+if ( q<fraction_four ) {
+ do {
+ if ( odd(f) ) p=halfp(p+q); else p=halfp(p);
+ f=halfp(f);
+ } while (f!=1);
+} else {
+ do {
+ if ( odd(f) ) p=p+halfp(q-p); else p=halfp(p);
+ f=halfp(f);
+ } while (f!=1);
+}
+
+
+@ When we want to multiply something by a |scaled| quantity, we use a scheme
+analogous to |take_fraction| but with a different scaling.
+Given positive operands, |take_scaled|
+computes the quantity $p=\lfloor qf/2^{16}+{1\over2}\rfloor$.
+
+Once again it is a good idea to use a machine-language replacement if
+possible; otherwise |take_scaled| will use more than 2\pct! of the running time
+when the Computer Modern fonts are being generated.
+@^inner loop@>
+
+@c
+#ifdef FIXPT
+integer mp_take_scaled (MP mp,integer q, scaled f) {
+ integer p; /* the fraction so far */
+ boolean negative; /* should the result be negated? */
+ integer n; /* additional multiple of $q$ */
+ integer be_careful; /* disables certain compiler optimizations */
+ @<Reduce to the case that |f>=0| and |q>=0|@>;
+ if ( f<unity ) {
+ n=0;
+ } else {
+ n=f / unity; f=f % unity;
+ if ( q<=el_gordo / n ) {
+ n=n*q;
+ } else {
+ mp->arith_error=true; n=el_gordo;
+ }
+ }
+ f=f+unity;
+ @<Compute $p=\lfloor qf/2^{16}+{1\over2}\rfloor-q$@>;
+ be_careful=n-el_gordo;
+ if ( be_careful+p>0 ) {
+ mp->arith_error=true; n=el_gordo-p;
+ }
+ return ( negative ?(-(n+p)) :(n+p));
+#else /* FIXPT */
+integer mp_take_scaled (MP mp,integer p, scaled q) {
+ register double d;
+ register integer i;
+ d = (double)p * (double)q * TWEXP_16;
+ if ((p^q) >= 0) {
+ d += 0.5;
+ if (d>=TWEXP31) {
+ if (d!=TWEXP31 || (((p&077777)*(q&077777))&040000)==0)
+ mp->arith_error = true;
+ return el_gordo;
+ }
+ i = (integer) d;
+ if (d==(double)i && (((p&077777)*(q&077777))&040000)!=0) --i;
+ } else {
+ d -= 0.5;
+ if (d<= -TWEXP31) {
+ if (d!= -TWEXP31 || ((-(p&077777)*(q&077777))&040000)==0)
+ mp->arith_error = true;
+ return -el_gordo;
+ }
+ i = (integer) d;
+ if (d==(double)i && ((-(p&077777)*(q&077777))&040000)!=0) ++i;
+ }
+ return i;
+#endif /* FIXPT */
+}
+
+@ @<Compute $p=\lfloor qf/2^{16}+{1\over2}\rfloor-q$@>=
+p=half_unit; /* that's $2^{15}$; the invariants hold now with $k=16$ */
+@^inner loop@>
+if ( q<fraction_four ) {
+ do {
+ p = (odd(f) ? halfp(p+q) : halfp(p));
+ f=halfp(f);
+ } while (f!=1);
+} else {
+ do {
+ p = (odd(f) ? p+halfp(q-p) : halfp(p));
+ f=halfp(f);
+ } while (f!=1);
+}
+
+@ For completeness, there's also |make_scaled|, which computes a
+quotient as a |scaled| number instead of as a |fraction|.
+In other words, the result is $\lfloor2^{16}p/q+{1\over2}\rfloor$, if the
+operands are positive. \ (This procedure is not used especially often,
+so it is not part of \MP's inner loop.)
+
+@<Internal library ...@>=
+scaled mp_make_scaled (MP mp,integer p, integer q) ;
+
+@ @c
+scaled mp_make_scaled (MP mp,integer p, integer q) {
+ register integer i;
+ if ( q==0 ) mp_confusion(mp, "/");
+@:this can't happen /}{\quad \./@>
+ {
+#ifdef FIXPT
+ integer f; /* the fraction bits, with a leading 1 bit */
+ integer n; /* the integer part of $\vert p/q\vert$ */
+ boolean negative; /* should the result be negated? */
+ integer be_careful; /* disables certain compiler optimizations */
+ if ( p>=0 ) negative=false;
+ else { negate(p); negative=true; };
+ if ( q<0 ) {
+ negate(q); negative=! negative;
+ }
+ n=p / q; p=p % q;
+ if ( n>=0100000 ) {
+ mp->arith_error=true;
+ return (negative ? (-el_gordo) : el_gordo);
+ } else {
+ n=(n-1)*unity;
+ @<Compute $f=\lfloor 2^{16}(1+p/q)+{1\over2}\rfloor$@>;
+ i = (negative ? (-(f+n)) :(f+n));
+ }
+#else /* FIXPT */
+ register double d;
+ d = TWEXP16 * (double)p /(double)q;
+ if ((p^q) >= 0) {
+ d += 0.5;
+ if (d>=TWEXP31) {mp->arith_error=true; return el_gordo;}
+ i = (integer) d;
+ if (d==(double)i && ( ((q>0 ? -q : q)&077777)
+ * (((i&037777)<<1)-1) & 04000)!=0) --i;
+ } else {
+ d -= 0.5;
+ if (d<= -TWEXP31) {mp->arith_error=true; return -el_gordo;}
+ i = (integer) d;
+ if (d==(double)i && ( ((q>0 ? q : -q)&077777)
+ * (((i&037777)<<1)+1) & 04000)!=0) ++i;
+ }
+#endif /* FIXPT */
+ }
+ return i;
+}
+
+@ @<Compute $f=\lfloor 2^{16}(1+p/q)+{1\over2}\rfloor$@>=
+f=1;
+do {
+ be_careful=p-q; p=be_careful+p;
+ if ( p>=0 ) f=f+f+1;
+ else { f+=f; p=p+q; };
+} while (f<unity);
+be_careful=p-q;
+if ( be_careful+p>=0 ) incr(f)
+
+@ Here is a typical example of how the routines above can be used.
+It computes the function
+$${1\over3\tau}f(\theta,\phi)=
+{\tau^{-1}\bigl(2+\sqrt2\,(\sin\theta-{1\over16}\sin\phi)
+ (\sin\phi-{1\over16}\sin\theta)(\cos\theta-\cos\phi)\bigr)\over
+3\,\bigl(1+{1\over2}(\sqrt5-1)\cos\theta+{1\over2}(3-\sqrt5\,)\cos\phi\bigr)},$$
+where $\tau$ is a |scaled| ``tension'' parameter. This is \MP's magic
+fudge factor for placing the first control point of a curve that starts
+at an angle $\theta$ and ends at an angle $\phi$ from the straight path.
+(Actually, if the stated quantity exceeds 4, \MP\ reduces it to~4.)
+
+The trigonometric quantity to be multiplied by $\sqrt2$ is less than $\sqrt2$.
+(It's a sum of eight terms whose absolute values can be bounded using
+relations such as $\sin\theta\cos\theta\L{1\over2}$.) Thus the numerator
+is positive; and since the tension $\tau$ is constrained to be at least
+$3\over4$, the numerator is less than $16\over3$. The denominator is
+nonnegative and at most~6. Hence the fixed-point calculations below
+are guaranteed to stay within the bounds of a 32-bit computer word.
+
+The angles $\theta$ and $\phi$ are given implicitly in terms of |fraction|
+arguments |st|, |ct|, |sf|, and |cf|, representing $\sin\theta$, $\cos\theta$,
+$\sin\phi$, and $\cos\phi$, respectively.
+
+@c
+static fraction mp_velocity (MP mp,fraction st, fraction ct, fraction sf,
+ fraction cf, scaled t) {
+ integer acc,num,denom; /* registers for intermediate calculations */
+ acc=mp_take_fraction(mp, st-(sf / 16), sf-(st / 16));
+ acc=mp_take_fraction(mp, acc,ct-cf);
+ num=fraction_two+mp_take_fraction(mp, acc,379625062);
+ /* $2^{28}\sqrt2\approx379625062.497$ */
+ denom=fraction_three+mp_take_fraction(mp, ct,497706707)+mp_take_fraction(mp, cf,307599661);
+ /* $3\cdot2^{27}\cdot(\sqrt5-1)\approx497706706.78$ and
+ $3\cdot2^{27}\cdot(3-\sqrt5\,)\approx307599661.22$ */
+ if ( t!=unity ) num=mp_make_scaled(mp, num,t);
+ /* |make_scaled(fraction,scaled)=fraction| */
+ if ( num / 4>=denom )
+ return fraction_four;
+ else
+ return mp_make_fraction(mp, num, denom);
+}
+
+@ The following somewhat different subroutine tests rigorously if $ab$ is
+greater than, equal to, or less than~$cd$,
+given integers $(a,b,c,d)$. In most cases a quick decision is reached.
+The result is $+1$, 0, or~$-1$ in the three respective cases.
+
+@d mp_ab_vs_cd(M,A,B,C,D) mp_do_ab_vs_cd(A,B,C,D)
+
+@c
+static integer mp_do_ab_vs_cd (integer a,integer b, integer c, integer d) {
+ integer q,r; /* temporary registers */
+ @<Reduce to the case that |a,c>=0|, |b,d>0|@>;
+ while (1) {
+ q = a / d; r = c / b;
+ if ( q!=r )
+ return ( q>r ? 1 : -1);
+ q = a % d; r = c % b;
+ if ( r==0 )
+ return (q ? 1 : 0);
+ if ( q==0 ) return -1;
+ a=b; b=q; c=d; d=r;
+ } /* now |a>d>0| and |c>b>0| */
+}
+
+@ @<Reduce to the case that |a...@>=
+if ( a<0 ) { negate(a); negate(b); };
+if ( c<0 ) { negate(c); negate(d); };
+if ( d<=0 ) {
+ if ( b>=0 ) {
+ if ( (a==0||b==0)&&(c==0||d==0) ) return 0;
+ else return 1;
+ }
+ if ( d==0 )
+ return ( a==0 ? 0 : -1);
+ q=a; a=c; c=q; q=-b; b=-d; d=q;
+} else if ( b<=0 ) {
+ if ( b<0 ) if ( a>0 ) return -1;
+ return (c==0 ? 0 : -1);
+}
+
+@ We conclude this set of elementary routines with some simple rounding
+and truncation operations.
+
+@<Internal library declarations@>=
+#define mp_floor_scaled(M,i) ((i)&(-65536))
+#define mp_round_unscaled(M,i) (i>0 ? (((i/32768)+1)/2) : (((i/32768)-1)/2))
+#define mp_round_fraction(M,i) (i>0 ? (((i/2048)+1)/2) : (((i/2048)-1)/2))
+
+
+@* \[8] Algebraic and transcendental functions.
+\MP\ computes all of the necessary special functions from scratch, without
+relying on |real| arithmetic or system subroutines for sines, cosines, etc.
+
+@ To get the square root of a |scaled| number |x|, we want to calculate
+$s=\lfloor 2^8\!\sqrt x +{1\over2}\rfloor$. If $x>0$, this is the unique
+integer such that $2^{16}x-s\L s^2<2^{16}x+s$. The following subroutine
+determines $s$ by an iterative method that maintains the invariant
+relations $x=2^{46-2k}x_0\bmod 2^{30}$, $0<y=\lfloor 2^{16-2k}x_0\rfloor
+-s^2+s\L q=2s$, where $x_0$ is the initial value of $x$. The value of~$y$
+might, however, be zero at the start of the first iteration.
+
+@<Declarations@>=
+static scaled mp_square_rt (MP mp,scaled x) ;
+
+@ @c
+scaled mp_square_rt (MP mp,scaled x) {
+ quarterword k; /* iteration control counter */
+ integer y; /* register for intermediate calculations */
+ unsigned q; /* register for intermediate calculations */
+ if ( x<=0 ) {
+ @<Handle square root of zero or negative argument@>;
+ } else {
+ k=23; q=2;
+ while ( x<fraction_two ) { /* i.e., |while x<@t$2^{29}$@>|\unskip */
+ decr(k); x=x+x+x+x;
+ }
+ if ( x<fraction_four ) y=0;
+ else { x=x-fraction_four; y=1; };
+ do {
+ @<Decrease |k| by 1, maintaining the invariant
+ relations between |x|, |y|, and~|q|@>;
+ } while (k!=0);
+ return (scaled)(halfp(q));
+ }
+}
+
+@ @<Handle square root of zero...@>=
+{
+ if ( x<0 ) {
+ print_err("Square root of ");
+@.Square root...replaced by 0@>
+ mp_print_scaled(mp, x); mp_print(mp, " has been replaced by 0");
+ help2("Since I don't take square roots of negative numbers,",
+ "I'm zeroing this one. Proceed, with fingers crossed.");
+ mp_error(mp);
+ };
+ return 0;
+}
+
+@ @<Decrease |k| by 1, maintaining...@>=
+x+=x; y+=y;
+if ( x>=fraction_four ) { /* note that |fraction_four=@t$2^{30}$@>| */
+ x=x-fraction_four; y++;
+};
+x+=x; y=y+y-q; q+=q;
+if ( x>=fraction_four ) { x=x-fraction_four; y++; };
+if ( y>(int)q ){ y=y-q; q=q+2; }
+else if ( y<=0 ) { q=q-2; y=y+q; };
+decr(k)
+
+@ Pythagorean addition $\psqrt{a^2+b^2}$ is implemented by an elegant
+iterative scheme due to Cleve Moler and Donald Morrison [{\sl IBM Journal
+@^Moler, Cleve Barry@>
+@^Morrison, Donald Ross@>
+of Research and Development\/ \bf27} (1983), 577--581]. It modifies |a| and~|b|
+in such a way that their Pythagorean sum remains invariant, while the
+smaller argument decreases.
+
+@<Internal library ...@>=
+integer mp_pyth_add (MP mp,integer a, integer b);
+
+
+@ @c
+integer mp_pyth_add (MP mp,integer a, integer b) {
+ fraction r; /* register used to transform |a| and |b| */
+ boolean big; /* is the result dangerously near $2^{31}$? */
+ a=abs(a); b=abs(b);
+ if ( a<b ) { r=b; b=a; a=r; }; /* now |0<=b<=a| */
+ if ( b>0 ) {
+ if ( a<fraction_two ) {
+ big=false;
+ } else {
+ a=a / 4; b=b / 4; big=true;
+ }; /* we reduced the precision to avoid arithmetic overflow */
+ @<Replace |a| by an approximation to $\psqrt{a^2+b^2}$@>;
+ if ( big ) {
+ if ( a<fraction_two ) {
+ a=a+a+a+a;
+ } else {
+ mp->arith_error=true; a=el_gordo;
+ };
+ }
+ }
+ return a;
+}
+
+@ The key idea here is to reflect the vector $(a,b)$ about the
+line through $(a,b/2)$.
+
+@<Replace |a| by an approximation to $\psqrt{a^2+b^2}$@>=
+while (1) {
+ r=mp_make_fraction(mp, b,a);
+ r=mp_take_fraction(mp, r,r); /* now $r\approx b^2/a^2$ */
+ if ( r==0 ) break;
+ r=mp_make_fraction(mp, r,fraction_four+r);
+ a=a+mp_take_fraction(mp, a+a,r); b=mp_take_fraction(mp, b,r);
+}
+
+
+@ Here is a similar algorithm for $\psqrt{a^2-b^2}$.
+It converges slowly when $b$ is near $a$, but otherwise it works fine.
+
+@c
+static integer mp_pyth_sub (MP mp,integer a, integer b) {
+ fraction r; /* register used to transform |a| and |b| */
+ boolean big; /* is the input dangerously near $2^{31}$? */
+ a=abs(a); b=abs(b);
+ if ( a<=b ) {
+ @<Handle erroneous |pyth_sub| and set |a:=0|@>;
+ } else {
+ if ( a<fraction_four ) {
+ big=false;
+ } else {
+ a=(integer)halfp(a); b=(integer)halfp(b); big=true;
+ }
+ @<Replace |a| by an approximation to $\psqrt{a^2-b^2}$@>;
+ if ( big ) double(a);
+ }
+ return a;
+}
+
+@ @<Replace |a| by an approximation to $\psqrt{a^2-b^2}$@>=
+while (1) {
+ r=mp_make_fraction(mp, b,a);
+ r=mp_take_fraction(mp, r,r); /* now $r\approx b^2/a^2$ */
+ if ( r==0 ) break;
+ r=mp_make_fraction(mp, r,fraction_four-r);
+ a=a-mp_take_fraction(mp, a+a,r); b=mp_take_fraction(mp, b,r);
+}
+
+@ @<Handle erroneous |pyth_sub| and set |a:=0|@>=
+{
+ if ( a<b ){
+ print_err("Pythagorean subtraction "); mp_print_scaled(mp, a);
+ mp_print(mp, "+-+"); mp_print_scaled(mp, b);
+ mp_print(mp, " has been replaced by 0");
+@.Pythagorean...@>
+ help2("Since I don't take square roots of negative numbers,",
+ "I'm zeroing this one. Proceed, with fingers crossed.");
+ mp_error(mp);
+ }
+ a=0;
+}
+
+@ The subroutines for logarithm and exponential involve two tables.
+The first is simple: |two_to_the[k]| equals $2^k$. The second involves
+a bit more calculation, which the author claims to have done correctly:
+|spec_log[k]| is $2^{27}$ times $\ln\bigl(1/(1-2^{-k})\bigr)=
+2^{-k}+{1\over2}2^{-2k}+{1\over3}2^{-3k}+\cdots\,$, rounded to the
+nearest integer.
+
+@d two_to_the(A) (1<<(unsigned)(A))
+
+@<Declarations@>=
+static const integer spec_log[29] = { 0, /* special logarithms */
+93032640, 38612034, 17922280, 8662214, 4261238, 2113709,
+1052693, 525315, 262400, 131136, 65552, 32772, 16385,
+8192, 4096, 2048, 1024, 512, 256, 128, 64, 32, 16, 8, 4, 2, 1, 1 };
+
+@ @<Local variables for initialization@>=
+integer k; /* all-purpose loop index */
+
+
+@ Here is the routine that calculates $2^8$ times the natural logarithm
+of a |scaled| quantity; it is an integer approximation to $2^{24}\ln(x/2^{16})$,
+when |x| is a given positive integer.
+
+The method is based on exercise 1.2.2--25 in {\sl The Art of Computer
+Programming\/}: During the main iteration we have $1\L 2^{-30}x<1/(1-2^{1-k})$,
+and the logarithm of $2^{30}x$ remains to be added to an accumulator
+register called~$y$. Three auxiliary bits of accuracy are retained in~$y$
+during the calculation, and sixteen auxiliary bits to extend |y| are
+kept in~|z| during the initial argument reduction. (We add
+$100\cdot2^{16}=6553600$ to~|z| and subtract 100 from~|y| so that |z| will
+not become negative; also, the actual amount subtracted from~|y| is~96,
+not~100, because we want to add~4 for rounding before the final division by~8.)
+
+@c
+static scaled mp_m_log (MP mp,scaled x) {
+ integer y,z; /* auxiliary registers */
+ integer k; /* iteration counter */
+ if ( x<=0 ) {
+ @<Handle non-positive logarithm@>;
+ } else {
+ y=1302456956+4-100; /* $14\times2^{27}\ln2\approx1302456956.421063$ */
+ z=27595+6553600; /* and $2^{16}\times .421063\approx 27595$ */
+ while ( x<fraction_four ) {
+ double(x); y-=93032639; z-=48782;
+ } /* $2^{27}\ln2\approx 93032639.74436163$ and $2^{16}\times.74436163\approx 48782$ */
+ y=y+(z / unity); k=2;
+ while ( x>fraction_four+4 ) {
+ @<Increase |k| until |x| can be multiplied by a
+ factor of $2^{-k}$, and adjust $y$ accordingly@>;
+ }
+ return (y / 8);
+ }
+}
+
+@ @<Increase |k| until |x| can...@>=
+{
+ z=((x-1) / two_to_the(k))+1; /* $z=\lceil x/2^k\rceil$ */
+ while ( x<fraction_four+z ) { z=halfp(z+1); k++; };
+ y+=spec_log[k]; x-=z;
+}
+
+@ @<Handle non-positive logarithm@>=
+{
+ print_err("Logarithm of ");
+@.Logarithm...replaced by 0@>
+ mp_print_scaled(mp, x); mp_print(mp, " has been replaced by 0");
+ help2("Since I don't take logs of non-positive numbers,",
+ "I'm zeroing this one. Proceed, with fingers crossed.");
+ mp_error(mp);
+ return 0;
+}
+
+@ Conversely, the exponential routine calculates $\exp(x/2^8)$,
+when |x| is |scaled|. The result is an integer approximation to
+$2^{16}\exp(x/2^{24})$, when |x| is regarded as an integer.
+
+@c
+static scaled mp_m_exp (MP mp,scaled x) {
+ quarterword k; /* loop control index */
+ integer y,z; /* auxiliary registers */
+ if ( x>174436200 ) {
+ /* $2^{24}\ln((2^{31}-1)/2^{16})\approx 174436199.51$ */
+ mp->arith_error=true;
+ return el_gordo;
+ } else if ( x<-197694359 ) {
+ /* $2^{24}\ln(2^{-1}/2^{16})\approx-197694359.45$ */
+ return 0;
+ } else {
+ if ( x<=0 ) {
+ z=-8*x; y=04000000; /* $y=2^{20}$ */
+ } else {
+ if ( x<=127919879 ) {
+ z=1023359037-8*x;
+ /* $2^{27}\ln((2^{31}-1)/2^{20})\approx 1023359037.125$ */
+ } else {
+ z=8*(174436200-x); /* |z| is always nonnegative */
+ }
+ y=el_gordo;
+ };
+ @<Multiply |y| by $\exp(-z/2^{27})$@>;
+ if ( x<=127919879 )
+ return ((y+8) / 16);
+ else
+ return y;
+ }
+}
+
+@ The idea here is that subtracting |spec_log[k]| from |z| corresponds
+to multiplying |y| by $1-2^{-k}$.
+
+A subtle point (which had to be checked) was that if $x=127919879$, the
+value of~|y| will decrease so that |y+8| doesn't overflow. In fact,
+$z$ will be 5 in this case, and |y| will decrease by~64 when |k=25|
+and by~16 when |k=27|.
+
+@<Multiply |y| by...@>=
+k=1;
+while ( z>0 ) {
+ while ( z>=spec_log[k] ) {
+ z-=spec_log[k];
+ y=y-1-((y-two_to_the(k-1)) / two_to_the(k));
+ }
+ k++;
+}
+
+@ The trigonometric subroutines use an auxiliary table such that
+|spec_atan[k]| contains an approximation to the |angle| whose tangent
+is~$1/2^k$. $\arctan2^{-k}$ times $2^{20}\cdot180/\pi$
+
+@<Declarations@>=
+static const angle spec_atan[27] = { 0, 27855475, 14718068, 7471121, 3750058,
+1876857, 938658, 469357, 234682, 117342, 58671, 29335, 14668, 7334, 3667,
+1833, 917, 458, 229, 115, 57, 29, 14, 7, 4, 2, 1 };
+
+@ Given integers |x| and |y|, not both zero, the |n_arg| function
+returns the |angle| whose tangent points in the direction $(x,y)$.
+This subroutine first determines the correct octant, then solves the
+problem for |0<=y<=x|, then converts the result appropriately to
+return an answer in the range |-one_eighty_deg<=@t$\theta$@><=one_eighty_deg|.
+(The answer is |+one_eighty_deg| if |y=0| and |x<0|, but an answer of
+|-one_eighty_deg| is possible if, for example, |y=-1| and $x=-2^{30}$.)
+
+The octants are represented in a ``Gray code,'' since that turns out
+to be computationally simplest.
+
+@d negate_x 1
+@d negate_y 2
+@d switch_x_and_y 4
+@d first_octant 1
+@d second_octant (first_octant+switch_x_and_y)
+@d third_octant (first_octant+switch_x_and_y+negate_x)
+@d fourth_octant (first_octant+negate_x)
+@d fifth_octant (first_octant+negate_x+negate_y)
+@d sixth_octant (first_octant+switch_x_and_y+negate_x+negate_y)
+@d seventh_octant (first_octant+switch_x_and_y+negate_y)
+@d eighth_octant (first_octant+negate_y)
+
+@c
+static angle mp_n_arg (MP mp,integer x, integer y) {
+ angle z; /* auxiliary register */
+ integer t; /* temporary storage */
+ quarterword k; /* loop counter */
+ int octant; /* octant code */
+ if ( x>=0 ) {
+ octant=first_octant;
+ } else {
+ negate(x); octant=first_octant+negate_x;
+ }
+ if ( y<0 ) {
+ negate(y); octant=octant+negate_y;
+ }
+ if ( x<y ) {
+ t=y; y=x; x=t; octant=octant+switch_x_and_y;
+ }
+ if ( x==0 ) {
+ @<Handle undefined arg@>;
+ } else {
+ @<Set variable |z| to the arg of $(x,y)$@>;
+ @<Return an appropriate answer based on |z| and |octant|@>;
+ }
+}
+
+@ @<Handle undefined arg@>=
+{
+ print_err("angle(0,0) is taken as zero");
+@.angle(0,0)...zero@>
+ help2("The `angle' between two identical points is undefined.",
+ "I'm zeroing this one. Proceed, with fingers crossed.");
+ mp_error(mp);
+ return 0;
+}
+
+@ @<Return an appropriate answer...@>=
+switch (octant) {
+case first_octant: return z;
+case second_octant: return (ninety_deg-z);
+case third_octant: return (ninety_deg+z);
+case fourth_octant: return (one_eighty_deg-z);
+case fifth_octant: return (z-one_eighty_deg);
+case sixth_octant: return (-z-ninety_deg);
+case seventh_octant: return (z-ninety_deg);
+case eighth_octant: return (-z);
+}; /* there are no other cases */
+return 0
+
+@ At this point we have |x>=y>=0|, and |x>0|. The numbers are scaled up
+or down until $2^{28}\L x<2^{29}$, so that accurate fixed-point calculations
+will be made.
+
+@<Set variable |z| to the arg...@>=
+while ( x>=fraction_two ) {
+ x=halfp(x); y=halfp(y);
+}
+z=0;
+if ( y>0 ) {
+ while ( x<fraction_one ) {
+ x+=x; y+=y;
+ };
+ @<Increase |z| to the arg of $(x,y)$@>;
+}
+
+@ During the calculations of this section, variables |x| and~|y|
+represent actual coordinates $(x,2^{-k}y)$. We will maintain the
+condition |x>=y|, so that the tangent will be at most $2^{-k}$.
+If $x<2y$, the tangent is greater than $2^{-k-1}$. The transformation
+$(a,b)\mapsto(a+b\tan\phi,b-a\tan\phi)$ replaces $(a,b)$ by
+coordinates whose angle has decreased by~$\phi$; in the special case
+$a=x$, $b=2^{-k}y$, and $\tan\phi=2^{-k-1}$, this operation reduces
+to the particularly simple iteration shown here. [Cf.~John E. Meggitt,
+@^Meggitt, John E.@>
+{\sl IBM Journal of Research and Development\/ \bf6} (1962), 210--226.]
+
+The initial value of |x| will be multiplied by at most
+$(1+{1\over2})(1+{1\over8})(1+{1\over32})\cdots\approx 1.7584$; hence
+there is no chance of integer overflow.
+
+@<Increase |z|...@>=
+k=0;
+do {
+ y+=y; k++;
+ if ( y>x ){
+ z=z+spec_atan[k]; t=x; x=x+(y / two_to_the(k+k)); y=y-t;
+ };
+} while (k!=15);
+do {
+ y+=y; k++;
+ if ( y>x ) { z=z+spec_atan[k]; y=y-x; };
+} while (k!=26)
+
+@ Conversely, the |n_sin_cos| routine takes an |angle| and produces the sine
+and cosine of that angle. The results of this routine are
+stored in global integer variables |n_sin| and |n_cos|.
+
+@<Glob...@>=
+fraction n_sin;fraction n_cos; /* results computed by |n_sin_cos| */
+
+@ Given an integer |z| that is $2^{20}$ times an angle $\theta$ in degrees,
+the purpose of |n_sin_cos(z)| is to set
+|x=@t$r\cos\theta$@>| and |y=@t$r\sin\theta$@>| (approximately),
+for some rather large number~|r|. The maximum of |x| and |y|
+will be between $2^{28}$ and $2^{30}$, so that there will be hardly
+any loss of accuracy. Then |x| and~|y| are divided by~|r|.
+
+@c
+static void mp_n_sin_cos (MP mp,angle z) { /* computes a multiple of the sine
+ and cosine */
+ quarterword k; /* loop control variable */
+ int q; /* specifies the quadrant */
+ fraction r; /* magnitude of |(x,y)| */
+ integer x,y,t; /* temporary registers */
+ while ( z<0 ) z=z+three_sixty_deg;
+ z=z % three_sixty_deg; /* now |0<=z<three_sixty_deg| */
+ q=z / forty_five_deg; z=z % forty_five_deg;
+ x=fraction_one; y=x;
+ if ( ! odd(q) ) z=forty_five_deg-z;
+ @<Subtract angle |z| from |(x,y)|@>;
+ @<Convert |(x,y)| to the octant determined by~|q|@>;
+ r=mp_pyth_add(mp, x,y);
+ mp->n_cos=mp_make_fraction(mp, x,r);
+ mp->n_sin=mp_make_fraction(mp, y,r);
+}
+
+@ In this case the octants are numbered sequentially.
+
+@<Convert |(x,...@>=
+switch (q) {
+case 0: break;
+case 1: t=x; x=y; y=t; break;
+case 2: t=x; x=-y; y=t; break;
+case 3: negate(x); break;
+case 4: negate(x); negate(y); break;
+case 5: t=x; x=-y; y=-t; break;
+case 6: t=x; x=y; y=-t; break;
+case 7: negate(y); break;
+} /* there are no other cases */
+
+@ The main iteration of |n_sin_cos| is similar to that of |n_arg| but
+applied in reverse. The values of |spec_atan[k]| decrease slowly enough
+that this loop is guaranteed to terminate before the (nonexistent) value
+|spec_atan[27]| would be required.
+
+@<Subtract angle |z|...@>=
+k=1;
+while ( z>0 ){
+ if ( z>=spec_atan[k] ) {
+ z=z-spec_atan[k]; t=x;
+ x=t+y / two_to_the(k);
+ y=y-t / two_to_the(k);
+ }
+ k++;
+}
+if ( y<0 ) y=0 /* this precaution may never be needed */
+
+@ And now let's complete our collection of numeric utility routines
+by considering random number generation.
+\MP\ generates pseudo-random numbers with the additive scheme recommended
+in Section 3.6 of {\sl The Art of Computer Programming}; however, the
+results are random fractions between 0 and |fraction_one-1|, inclusive.
+
+There's an auxiliary array |randoms| that contains 55 pseudo-random
+fractions. Using the recurrence $x_n=(x_{n-55}-x_{n-31})\bmod 2^{28}$,
+we generate batches of 55 new $x_n$'s at a time by calling |new_randoms|.
+The global variable |j_random| tells which element has most recently
+been consumed.
+The global variable |random_seed| was introduced in version 0.9,
+for the sole reason of stressing the fact that the initial value of the
+random seed is system-dependant. The initialization code below will initialize
+this variable to |(internal[mp_time] div unity)+internal[mp_day]|, but this
+is not good enough on modern fast machines that are capable of running
+multiple MetaPost processes within the same second.
+@^system dependencies@>
+
+@<Glob...@>=
+fraction randoms[55]; /* the last 55 random values generated */
+int j_random; /* the number of unused |randoms| */
+
+@ @<Option variables@>=
+int random_seed; /* the default random seed */
+
+@ @<Allocate or initialize ...@>=
+mp->random_seed = (scaled)opt->random_seed;
+
+@ To consume a random fraction, the program below will say `|next_random|'
+and then it will fetch |randoms[j_random]|.
+
+@d next_random { if ( mp->j_random==0 ) mp_new_randoms(mp);
+ else decr(mp->j_random); }
+
+@c
+static void mp_new_randoms (MP mp) {
+ int k; /* index into |randoms| */
+ fraction x; /* accumulator */
+ for (k=0;k<=23;k++) {
+ x=mp->randoms[k]-mp->randoms[k+31];
+ if ( x<0 ) x=x+fraction_one;
+ mp->randoms[k]=x;
+ }
+ for (k=24;k<= 54;k++){
+ x=mp->randoms[k]-mp->randoms[k-24];
+ if ( x<0 ) x=x+fraction_one;
+ mp->randoms[k]=x;
+ }
+ mp->j_random=54;
+}
+
+@ @<Declarations@>=
+static void mp_init_randoms (MP mp,scaled seed);
+
+@ To initialize the |randoms| table, we call the following routine.
+
+@c
+void mp_init_randoms (MP mp,scaled seed) {
+ fraction j,jj,k; /* more or less random integers */
+ int i; /* index into |randoms| */
+ j=abs(seed);
+ while ( j>=fraction_one ) j=halfp(j);
+ k=1;
+ for (i=0;i<=54;i++ ){
+ jj=k; k=j-k; j=jj;
+ if ( k<0 ) k=k+fraction_one;
+ mp->randoms[(i*21)% 55]=j;
+ }
+ mp_new_randoms(mp);
+ mp_new_randoms(mp);
+ mp_new_randoms(mp); /* ``warm up'' the array */
+}
+
+@ To produce a uniform random number in the range |0<=u<x| or |0>=u>x|
+or |0=u=x|, given a |scaled| value~|x|, we proceed as shown here.
+
+Note that the call of |take_fraction| will produce the values 0 and~|x|
+with about half the probability that it will produce any other particular
+values between 0 and~|x|, because it rounds its answers.
+
+@c
+static scaled mp_unif_rand (MP mp,scaled x) {
+ scaled y; /* trial value */
+ next_random; y=mp_take_fraction(mp, abs(x),mp->randoms[mp->j_random]);
+ if ( y==abs(x) ) return 0;
+ else if ( x>0 ) return y;
+ else return (-y);
+}
+
+@ Finally, a normal deviate with mean zero and unit standard deviation
+can readily be obtained with the ratio method (Algorithm 3.4.1R in
+{\sl The Art of Computer Programming\/}).
+
+@c
+static scaled mp_norm_rand (MP mp) {
+ integer x,u,l; /* what the book would call $2^{16}X$, $2^{28}U$, and $-2^{24}\ln U$ */
+ do {
+ do {
+ next_random;
+ x=mp_take_fraction(mp, 112429,mp->randoms[mp->j_random]-fraction_half);
+ /* $2^{16}\sqrt{8/e}\approx 112428.82793$ */
+ next_random; u=mp->randoms[mp->j_random];
+ } while (abs(x)>=u);
+ x=mp_make_fraction(mp, x,u);
+ l=139548960-mp_m_log(mp, u); /* $2^{24}\cdot12\ln2\approx139548959.6165$ */
+ } while (mp_ab_vs_cd(mp, 1024,l,x,x)<0);
+ return x;
+}
+
+@* \[9] Packed data.
+In order to make efficient use of storage space, \MP\ bases its major data
+structures on a |memory_word|, which contains either a (signed) integer,
+possibly scaled, or a small number of fields that are one half or one
+quarter of the size used for storing integers.
+
+If |x| is a variable of type |memory_word|, it contains up to four
+fields that can be referred to as follows:
+$$\vbox{\halign{\hfil#&#\hfil&#\hfil\cr
+|x|&.|int|&(an |integer|)\cr
+|x|&.|sc|\qquad&(a |scaled| integer)\cr
+|x.hh.lh|, |x.hh|&.|rh|&(two halfword fields)\cr
+|x.hh.b0|, |x.hh.b1|, |x.hh|&.|rh|&(two quarterword fields, one halfword
+ field)\cr
+|x.qqqq.b0|, |x.qqqq.b1|, |x.qqqq|&.|b2|, |x.qqqq.b3|\hskip-100pt
+ &\qquad\qquad\qquad(four quarterword fields)\cr}}$$
+This is somewhat cumbersome to write, and not very readable either, but
+macros will be used to make the notation shorter and more transparent.
+The code below gives a formal definition of |memory_word| and
+its subsidiary types, using packed variant records. \MP\ makes no
+assumptions about the relative positions of the fields within a word.
+
+@d max_quarterword 0x3FFF /* largest allowable value in a |quarterword| */
+@d max_halfword 0xFFFFFFF /* largest allowable value in a |halfword| */
+
+@ Here are the inequalities that the quarterword and halfword values
+must satisfy (or rather, the inequalities that they mustn't satisfy):
+
+@<Check the ``constant''...@>=
+if (mp->ini_version) {
+ if ( mp->mem_max!=mp->mem_top ) mp->bad=8;
+} else {
+ if ( mp->mem_max<mp->mem_top ) mp->bad=8;
+}
+if ( mp->mem_max>=max_halfword ) mp->bad=12;
+if ( mp->max_strings>max_halfword ) mp->bad=13;
+
+@ The macros |qi| and |qo| are used for input to and output
+from quarterwords. These are legacy macros.
+@^system dependencies@>
+
+@d qo(A) (A) /* to read eight bits from a quarterword */
+@d qi(A) (quarterword)(A) /* to store eight bits in a quarterword */
+
+@ The reader should study the following definitions closely:
+@^system dependencies@>
+
+@d sc cint /* |scaled| data is equivalent to |integer| */
+
+@<Types...@>=
+typedef short quarterword; /* 1/4 of a word */
+typedef int halfword; /* 1/2 of a word */
+typedef union {
+ struct {
+ halfword RH, LH;
+ } v;
+ struct { /* Make B0,B1 overlap the most significant bytes of LH. */
+ halfword junk;
+ quarterword B0, B1;
+ } u;
+} two_halves;
+typedef struct {
+ struct {
+ quarterword B2, B3, B0, B1;
+ } u;
+} four_quarters;
+typedef union {
+ two_halves hh;
+ integer cint;
+ four_quarters qqqq;
+} memory_word;
+#define b0 u.B0
+#define b1 u.B1
+#define b2 u.B2
+#define b3 u.B3
+#define rh v.RH
+#define lh v.LH
+
+@ When debugging, we may want to print a |memory_word| without knowing
+what type it is; so we print it in all modes.
+@^debugging@>
+
+@c
+void mp_print_word (MP mp,memory_word w) {
+ /* prints |w| in all ways */
+ mp_print_int(mp, w.cint); mp_print_char(mp, xord(' '));
+ mp_print_scaled(mp, w.sc); mp_print_char(mp, xord(' '));
+ mp_print_scaled(mp, w.sc / 010000); mp_print_ln(mp);
+ mp_print_int(mp, w.hh.lh); mp_print_char(mp, xord('='));
+ mp_print_int(mp, w.hh.b0); mp_print_char(mp, xord(':'));
+ mp_print_int(mp, w.hh.b1); mp_print_char(mp, xord(';'));
+ mp_print_int(mp, w.hh.rh); mp_print_char(mp, xord(' '));
+ mp_print_int(mp, w.qqqq.b0); mp_print_char(mp, xord(':'));
+ mp_print_int(mp, w.qqqq.b1); mp_print_char(mp, xord(':'));
+ mp_print_int(mp, w.qqqq.b2); mp_print_char(mp, xord(':'));
+ mp_print_int(mp, w.qqqq.b3);
+}
+
+
+@* \[10] Dynamic memory allocation.
+
+The \MP\ system does nearly all of its own memory allocation, so that it
+can readily be transported into environments that do not have automatic
+facilities for strings, garbage collection, etc., and so that it can be in
+control of what error messages the user receives. The dynamic storage
+requirements of \MP\ are handled by providing a large array |mem| in
+which consecutive blocks of words are used as nodes by the \MP\ routines.
+
+Pointer variables are indices into this array, or into another array
+called |eqtb| that will be explained later. A pointer variable might
+also be a special flag that lies outside the bounds of |mem|, so we
+allow pointers to assume any |halfword| value. The minimum memory
+index represents a null pointer.
+
+@d null 0 /* the null pointer */
+@d mp_void (null+1) /* a null pointer different from |null| */
+
+
+@<Types...@>=
+typedef halfword pointer; /* a flag or a location in |mem| or |eqtb| */
+
+@ The |mem| array is divided into two regions that are allocated separately,
+but the dividing line between these two regions is not fixed; they grow
+together until finding their ``natural'' size in a particular job.
+Locations less than or equal to |lo_mem_max| are used for storing
+variable-length records consisting of two or more words each. This region
+is maintained using an algorithm similar to the one described in exercise
+2.5--19 of {\sl The Art of Computer Programming}. However, no size field
+appears in the allocated nodes; the program is responsible for knowing the
+relevant size when a node is freed. Locations greater than or equal to
+|hi_mem_min| are used for storing one-word records; a conventional
+\.{AVAIL} stack is used for allocation in this region.
+
+Locations of |mem| between |0| and |mem_top| may be dumped as part
+of preloaded mem files, by the \.{INIMP} preprocessor.
+@.INIMP@>
+Production versions of \MP\ may extend the memory at the top end in order to
+provide more space; these locations, between |mem_top| and |mem_max|,
+are always used for single-word nodes.
+
+The key pointers that govern |mem| allocation have a prescribed order:
+$$\hbox{|null=0<lo_mem_max<hi_mem_min<mem_top<=mem_end<=mem_max|.}$$
+
+@<Glob...@>=
+memory_word *mem; /* the big dynamic storage area */
+pointer lo_mem_max; /* the largest location of variable-size memory in use */
+pointer hi_mem_min; /* the smallest location of one-word memory in use */
+
+
+@
+@d xfree(A) do { mp_xfree(A); A=NULL; } while (0)
+@d xrealloc(P,A,B) mp_xrealloc(mp,P,(size_t)A,B)
+@d xmalloc(A,B) mp_xmalloc(mp,(size_t)A,B)
+@d xstrdup(A) mp_xstrdup(mp,A)
+@d XREALLOC(a,b,c) a = xrealloc(a,(b+1),sizeof(c));
+
+@<Declare helpers@>=
+extern char *mp_strdup(const char *p) ;
+extern char *mp_strldup(const char *p, size_t l) ;
+extern void mp_xfree ( @= /*@@only@@*/ /*@@out@@*/ /*@@null@@*/ @> void *x);
+extern @= /*@@only@@*/ @> void *mp_xrealloc (MP mp, void *p, size_t nmem, size_t size) ;
+extern @= /*@@only@@*/ @> void *mp_xmalloc (MP mp, size_t nmem, size_t size) ;
+extern @= /*@@only@@*/ @> char *mp_xstrdup(MP mp, const char *s);
+extern @= /*@@only@@*/ @> char *mp_xstrldup(MP mp, const char *s, size_t l);
+extern void mp_do_snprintf(char *str, int size, const char *fmt, ...);
+
+@ The |max_size_test| guards against overflow, on the assumption that
+|size_t| is at least 31bits wide.
+
+@d max_size_test 0x7FFFFFFF
+
+@c
+char *mp_strldup(const char *p, size_t l) {
+ char *r;
+ if (p==NULL) return NULL;
+ r = malloc ((size_t)(l*sizeof(char)+1));
+ if (r==NULL)
+ return NULL;
+ return memcpy (r,p,(size_t)(l+1));
+}
+char *mp_strdup(const char *p) {
+ if (p==NULL) return NULL;
+ return mp_strldup(p, strlen(p));
+}
+void mp_xfree (void *x) {
+ if (x!=NULL) free(x);
+}
+void *mp_xrealloc (MP mp, void *p, size_t nmem, size_t size) {
+ void *w ;
+ if ((max_size_test/size)<nmem) {
+ do_fprintf(mp->err_out,"Memory size overflow!\n");
+ mp->history =mp_fatal_error_stop; mp_jump_out(mp);
+ }
+ w = realloc (p,(nmem*size));
+ if (w==NULL) {
+ do_fprintf(mp->err_out,"Out of memory!\n");
+ mp->history =mp_system_error_stop; mp_jump_out(mp);
+ }
+ return w;
+}
+void *mp_xmalloc (MP mp, size_t nmem, size_t size) {
+ void *w;
+ if ((max_size_test/size)<nmem) {
+ do_fprintf(mp->err_out,"Memory size overflow!\n");
+ mp->history =mp_fatal_error_stop; mp_jump_out(mp);
+ }
+ w = malloc (nmem*size);
+ if (w==NULL) {
+ do_fprintf(mp->err_out,"Out of memory!\n");
+ mp->history =mp_system_error_stop; mp_jump_out(mp);
+ }
+ return w;
+}
+char *mp_xstrldup(MP mp, const char *s, size_t l) {
+ char *w;
+ if (s==NULL)
+ return NULL;
+ w = mp_strldup(s, l);
+ if (w==NULL) {
+ do_fprintf(mp->err_out,"Out of memory!\n");
+ mp->history =mp_system_error_stop; mp_jump_out(mp);
+ }
+ return w;
+}
+char *mp_xstrdup(MP mp, const char *s) {
+ if (s==NULL) return NULL;
+ return mp_xstrldup(mp,s,strlen(s));
+}
+
+
+@ @<Internal library declarations@>=
+#ifdef HAVE_SNPRINTF
+#define mp_snprintf (void)snprintf
+#else
+#define mp_snprintf mp_do_snprintf
+#endif
+
+@ This internal version is rather stupid, but good enough for its purpose.
+
+@c
+static char *mp_itoa (int i) {
+ char res[32] ;
+ unsigned idx = 30;
+ unsigned v = (unsigned)abs(i);
+ memset(res,0,32*sizeof(char));
+ while (v>=10) {
+ char d = (char)(v % 10);
+ v = v / 10;
+ res[idx--] = (char)d + '0';
+ }
+ res[idx--] = (char)v + '0';
+ if (i<0) {
+ res[idx--] = '-';
+ }
+ return mp_strdup((res+idx+1));
+}
+static char *mp_utoa (unsigned v) {
+ char res[32] ;
+ unsigned idx = 30;
+ memset(res,0,32*sizeof(char));
+ while (v>=10) {
+ char d = (char)(v % 10);
+ v = v / 10;
+ res[idx--] = d + '0';
+ }
+ res[idx--] = (char)v + '0';
+ return mp_strdup((res+idx+1));
+}
+void mp_do_snprintf (char *str, int size, const char *format, ...) {
+ const char *fmt;
+ char *res;
+ int fw, pad;
+ va_list ap;
+ va_start(ap, format);
+ res = str;
+ for (fmt=format;*fmt!='\0';fmt++) {
+ if (*fmt=='%') {
+ fw=0;
+ pad=0;
+ fmt++;
+ switch(*fmt) {
+ case '0':
+ pad=1;
+ break;
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7':
+ case '8':
+ case '9':
+ assert(fw==0);
+ fw = *fmt-'0';
+ break;
+ case 's':
+ {
+ char *s = va_arg(ap, char *);
+ while (*s) {
+ *res = *s++;
+ if (size-->0) res++;
+ }
+ }
+ break;
+ case 'i':
+ case 'd':
+ {
+ char *s = mp_itoa(va_arg(ap, int));
+ if (fw) {
+ int ffw = fw-strlen(s);
+ while (ffw-->0) {
+ *res = (pad ? '0' : ' ');
+ if (size-->0) res++;
+ }
+ }
+ if (s != NULL) {
+ while (*s) {
+ *res = *s++;
+ if (size-->0) res++;
+ }
+ }
+ }
+ break;
+ case 'u':
+ {
+ char *s = mp_utoa(va_arg(ap, unsigned));
+ if (fw) {
+ int ffw = fw-strlen(s);
+ while (ffw-->0) {
+ *res = (pad ? '0' : ' ');
+ if (size-->0) res++;
+ }
+ }
+ if (s != NULL) {
+ while (*s) {
+ *res = *s++;
+ if (size-->0) res++;
+ }
+ }
+ }
+ break;
+ case '%':
+ *res = '%';
+ if (size-->0) res++;
+ break;
+ default:
+ *res = '%';
+ if (size-->0) res++;
+ *res = *fmt;
+ if (size-->0) res++;
+ break;
+ }
+ } else {
+ *res = *fmt;
+ if (size-->0) res++;
+ }
+ }
+ *res = '\0';
+ va_end(ap);
+}
+
+@
+@<Allocate or initialize ...@>=
+mp->mem = xmalloc ((mp->mem_max+1),sizeof (memory_word));
+memset(mp->mem,0,(mp->mem_max+1)*sizeof (memory_word));
+
+@ @<Dealloc variables@>=
+xfree(mp->mem);
+
+@ Users who wish to study the memory requirements of particular applications can
+can use optional special features that keep track of current and
+maximum memory usage. When code between the delimiters |stat| $\ldots$
+|tats| is not ``commented out,'' \MP\ will run a bit slower but it will
+report these statistics when |mp_tracing_stats| is positive.
+
+@<Glob...@>=
+integer var_used; integer dyn_used; /* how much memory is in use */
+
+@ Let's consider the one-word memory region first, since it's the
+simplest. The pointer variable |mem_end| holds the highest-numbered location
+of |mem| that has ever been used. The free locations of |mem| that
+occur between |hi_mem_min| and |mem_end|, inclusive, are of type
+|two_halves|, and we write |info(p)| and |mp_link(p)| for the |lh|
+and |rh| fields of |mem[p]| when it is of this type. The single-word
+free locations form a linked list
+$$|avail|,\;\hbox{|mp_link(avail)|},\;\hbox{|mp_link(mp_link(avail))|},\;\ldots$$
+terminated by |null|.
+
+@(mpmp.h@>=
+#define mp_link(A) mp->mem[(A)].hh.rh /* the |link| field of a memory word */
+#define mp_info(A) mp->mem[(A)].hh.lh /* the |info| field of a memory word */
+
+@ @<Glob...@>=
+pointer avail; /* head of the list of available one-word nodes */
+pointer mem_end; /* the last one-word node used in |mem| */
+
+@ If one-word memory is exhausted, it might mean that the user has forgotten
+a token like `\&{enddef}' or `\&{endfor}'. We will define some procedures
+later that try to help pinpoint the trouble.
+
+@ The function |get_avail| returns a pointer to a new one-word node whose
+|link| field is null. However, \MP\ will halt if there is no more room left.
+@^inner loop@>
+
+@c
+static pointer mp_get_avail (MP mp) { /* single-word node allocation */
+ pointer p; /* the new node being got */
+ p=mp->avail; /* get top location in the |avail| stack */
+ if ( p!=null ) {
+ mp->avail=mp_link(mp->avail); /* and pop it off */
+ } else if ( mp->mem_end<mp->mem_max ) { /* or go into virgin territory */
+ incr(mp->mem_end); p=mp->mem_end;
+ } else {
+ decr(mp->hi_mem_min); p=mp->hi_mem_min;
+ if ( mp->hi_mem_min<=mp->lo_mem_max ) {
+ mp_runaway(mp); /* if memory is exhausted, display possible runaway text */
+ mp_overflow(mp, "main memory size",mp->mem_max);
+ /* quit; all one-word nodes are busy */
+@:MetaPost capacity exceeded main memory size}{\quad main memory size@>
+ }
+ }
+ mp_link(p)=null; /* provide an oft-desired initialization of the new node */
+ incr(mp->dyn_used);/* maintain statistics */
+ return p;
+}
+
+@ Conversely, a one-word node is recycled by calling |free_avail|.
+
+@d free_avail(A) /* single-word node liberation */
+ { mp_link((A))=mp->avail; mp->avail=(A); decr(mp->dyn_used); }
+
+@ There's also a |fast_get_avail| routine, which saves the procedure-call
+overhead at the expense of extra programming. This macro is used in
+the places that would otherwise account for the most calls of |get_avail|.
+@^inner loop@>
+
+@d fast_get_avail(A) {
+ (A)=mp->avail; /* avoid |get_avail| if possible, to save time */
+ if ( (A)==null ) { (A)=mp_get_avail(mp); }
+ else { mp->avail=mp_link((A)); mp_link((A))=null; incr(mp->dyn_used); }
+ }
+
+@ The available-space list that keeps track of the variable-size portion
+of |mem| is a nonempty, doubly-linked circular list of empty nodes,
+pointed to by the roving pointer |rover|.
+
+Each empty node has size 2 or more; the first word contains the special
+value |max_halfword| in its |link| field and the size in its |info| field;
+the second word contains the two pointers for double linking.
+
+Each nonempty node also has size 2 or more. Its first word is of type
+|two_halves|\kern-1pt, and its |link| field is never equal to |max_halfword|.
+Otherwise there is complete flexibility with respect to the contents
+of its other fields and its other words.
+
+(We require |mem_max<max_halfword| because terrible things can happen
+when |max_halfword| appears in the |link| field of a nonempty node.)
+
+@d empty_flag max_halfword /* the |link| of an empty variable-size node */
+@d is_empty(A) (mp_link((A))==empty_flag) /* tests for empty node */
+
+@(mpmp.h@>=
+#define node_size mp_info /* the size field in empty variable-size nodes */
+#define lmp_link(A) mp_info((A)+1) /* left link in doubly-linked list of empty nodes */
+#define rmp_link(A) mp_link((A)+1) /* right link in doubly-linked list of empty nodes */
+
+@ @<Glob...@>=
+pointer rover; /* points to some node in the list of empties */
+
+@ A call to |get_node| with argument |s| returns a pointer to a new node
+of size~|s|, which must be 2~or more. The |link| field of the first word
+of this new node is set to null. An overflow stop occurs if no suitable
+space exists.
+
+If |get_node| is called with $s=2^{30}$, it simply merges adjacent free
+areas and returns the value |max_halfword|.
+
+@<Internal library declarations@>=
+pointer mp_get_node (MP mp,integer s) ;
+
+@ @c
+pointer mp_get_node (MP mp,integer s) { /* variable-size node allocation */
+ pointer p; /* the node currently under inspection */
+ pointer q; /* the node physically after node |p| */
+ integer r; /* the newly allocated node, or a candidate for this honor */
+ integer t,tt; /* temporary registers */
+@^inner loop@>
+ RESTART:
+ p=mp->rover; /* start at some free node in the ring */
+ do {
+ @<Try to allocate within node |p| and its physical successors,
+ and |goto found| if allocation was possible@>;
+ if (rmp_link(p)==null || (rmp_link(p)==p && p!=mp->rover)) {
+ print_err("Free list garbled");
+ help3("I found an entry in the list of free nodes that links",
+ "badly. I will try to ignore the broken link, but something",
+ "is seriously amiss. It is wise to warn the maintainers.")
+ mp_error(mp);
+ rmp_link(p)=mp->rover;
+ }
+ p=rmp_link(p); /* move to the next node in the ring */
+ } while (p!=mp->rover); /* repeat until the whole list has been traversed */
+ if ( s==010000000000 ) {
+ return max_halfword;
+ };
+ if ( mp->lo_mem_max+2<mp->hi_mem_min ) {
+ if ( mp->lo_mem_max+2<=max_halfword ) {
+ @<Grow more variable-size memory and |goto restart|@>;
+ }
+ }
+ mp_overflow(mp, "main memory size",mp->mem_max);
+ /* sorry, nothing satisfactory is left */
+@:MetaPost capacity exceeded main memory size}{\quad main memory size@>
+FOUND:
+ mp_link(r)=null; /* this node is now nonempty */
+ mp->var_used+=s; /* maintain usage statistics */
+ return r;
+}
+
+@ The lower part of |mem| grows by 1000 words at a time, unless
+we are very close to going under. When it grows, we simply link
+a new node into the available-space list. This method of controlled
+growth helps to keep the |mem| usage consecutive when \MP\ is
+implemented on ``virtual memory'' systems.
+@^virtual memory@>
+
+@<Grow more variable-size memory and |goto restart|@>=
+{
+ if ( mp->hi_mem_min-mp->lo_mem_max>=1998 ) {
+ t=mp->lo_mem_max+1000;
+ } else {
+ t=mp->lo_mem_max+1+(mp->hi_mem_min-mp->lo_mem_max) / 2;
+ /* |lo_mem_max+2<=t<hi_mem_min| */
+ }
+ if ( t>max_halfword ) t=max_halfword;
+ p=lmp_link(mp->rover); q=mp->lo_mem_max; rmp_link(p)=q; lmp_link(mp->rover)=q;
+ rmp_link(q)=mp->rover; lmp_link(q)=p; mp_link(q)=empty_flag;
+ node_size(q)=t-mp->lo_mem_max;
+ mp->lo_mem_max=t; mp_link(mp->lo_mem_max)=null; mp_info(mp->lo_mem_max)=null;
+ mp->rover=q;
+ goto RESTART;
+}
+
+@ @<Try to allocate...@>=
+q=p+node_size(p); /* find the physical successor */
+while ( is_empty(q) ) { /* merge node |p| with node |q| */
+ t=rmp_link(q); tt=lmp_link(q);
+@^inner loop@>
+ if ( q==mp->rover ) mp->rover=t;
+ lmp_link(t)=tt; rmp_link(tt)=t;
+ q=q+node_size(q);
+}
+r=q-s;
+if ( r>p+1 ) {
+ @<Allocate from the top of node |p| and |goto found|@>;
+}
+if ( r==p ) {
+ if ( rmp_link(p)!=p ) {
+ @<Allocate entire node |p| and |goto found|@>;
+ }
+}
+node_size(p)=q-p /* reset the size in case it grew */
+
+@ @<Allocate from the top...@>=
+{
+ node_size(p)=r-p; /* store the remaining size */
+ mp->rover=p; /* start searching here next time */
+ goto FOUND;
+}
+
+@ Here we delete node |p| from the ring, and let |rover| rove around.
+
+@<Allocate entire...@>=
+{
+ mp->rover=rmp_link(p); t=lmp_link(p);
+ lmp_link(mp->rover)=t; rmp_link(t)=mp->rover;
+ goto FOUND;
+}
+
+@ Conversely, when some variable-size node |p| of size |s| is no longer needed,
+the operation |free_node(p,s)| will make its words available, by inserting
+|p| as a new empty node just before where |rover| now points.
+
+@<Internal library declarations@>=
+void mp_free_node (MP mp, pointer p, halfword s) ;
+
+@ @c
+void mp_free_node (MP mp, pointer p, halfword s) { /* variable-size node
+ liberation */
+ pointer q; /* |lmp_link(rover)| */
+ node_size(p)=s; mp_link(p)=empty_flag;
+@^inner loop@>
+ q=lmp_link(mp->rover); lmp_link(p)=q; rmp_link(p)=mp->rover; /* set both links */
+ lmp_link(mp->rover)=p; rmp_link(q)=p; /* insert |p| into the ring */
+ mp->var_used-=s; /* maintain statistics */
+}
+
+@* \[11] Memory layout.
+Some areas of |mem| are dedicated to fixed usage, since static allocation is
+more efficient than dynamic allocation when we can get away with it. For
+example, locations |0| to |1| are always used to store a
+two-word dummy token whose second word is zero.
+The following macro definitions accomplish the static allocation by giving
+symbolic names to the fixed positions. Static variable-size nodes appear
+in locations |0| through |lo_mem_stat_max|, and static single-word nodes
+appear in locations |hi_mem_stat_min| through |mem_top|, inclusive.
+
+@d sentinel mp->mem_top /* end of sorted lists */
+@d temp_head (mp->mem_top-1) /* head of a temporary list of some kind */
+@d hold_head (mp->mem_top-2) /* head of a temporary list of another kind */
+
+@(mpmp.h@>=
+#define spec_head (mp->mem_top-3) /* head of a list of unprocessed \&{special} items */
+#define null_dash (2) /* the first two words are reserved for a null value */
+#define dep_head (null_dash+3) /* we will define |dash_node_size=3| */
+#define zero_val (dep_head+2) /* two words for a permanently zero value */
+#define temp_val (zero_val+2) /* two words for a temporary value node */
+#define end_attr temp_val /* we use |end_attr+2| only */
+#define inf_val (end_attr+2) /* and |inf_val+1| only */
+#define bad_vardef (inf_val+2) /* two words for \&{vardef} error recovery */
+#define lo_mem_stat_max (bad_vardef+1) /* largest statically
+ allocated word in the variable-size |mem| */
+#define hi_mem_stat_min (mp->mem_top-3) /* smallest statically allocated word in
+ the one-word |mem| */
+
+@ The following code gets the dynamic part of |mem| off to a good start,
+when \MP\ is initializing itself the slow way.
+
+@<Initialize table entries (done by \.{INIMP} only)@>=
+mp->rover=lo_mem_stat_max+1; /* initialize the dynamic memory */
+mp_link(mp->rover)=empty_flag;
+node_size(mp->rover)=1000; /* which is a 1000-word available node */
+lmp_link(mp->rover)=mp->rover; rmp_link(mp->rover)=mp->rover;
+mp->lo_mem_max=mp->rover+1000;
+mp_link(mp->lo_mem_max)=null; mp_info(mp->lo_mem_max)=null;
+for (k=hi_mem_stat_min;k<=(int)mp->mem_top;k++) {
+ mp->mem[k]=mp->mem[mp->lo_mem_max]; /* clear list heads */
+}
+mp->avail=null; mp->mem_end=mp->mem_top;
+mp->hi_mem_min=hi_mem_stat_min; /* initialize the one-word memory */
+mp->var_used=lo_mem_stat_max+1;
+mp->dyn_used=mp->mem_top+1-(hi_mem_stat_min); /* initialize statistics */
+
+@ The procedure |flush_list(p)| frees an entire linked list of one-word
+nodes that starts at a given position, until coming to |sentinel| or a
+pointer that is not in the one-word region. Another procedure,
+|flush_node_list|, frees an entire linked list of one-word and two-word
+nodes, until coming to a |null| pointer.
+@^inner loop@>
+
+@c
+static void mp_flush_list (MP mp,pointer p) { /* makes list of single-word nodes available */
+ pointer q,r; /* list traversers */
+ if ( p>=mp->hi_mem_min ) if ( p!=sentinel ) {
+ r=p;
+ do {
+ q=r; r=mp_link(r);
+ decr(mp->dyn_used);
+ if ( r<mp->hi_mem_min ) break;
+ } while (r!=sentinel);
+ /* now |q| is the last node on the list */
+ mp_link(q)=mp->avail; mp->avail=p;
+ }
+}
+@#
+static void mp_flush_node_list (MP mp,pointer p) {
+ pointer q; /* the node being recycled */
+ while ( p!=null ){
+ q=p; p=mp_link(p);
+ if ( q<mp->hi_mem_min )
+ mp_free_node(mp, q,2);
+ else
+ free_avail(q);
+ }
+}
+
+@ If \MP\ is extended improperly, the |mem| array might get screwed up.
+For example, some pointers might be wrong, or some ``dead'' nodes might not
+have been freed when the last reference to them disappeared. Procedures
+|check_mem| and |search_mem| are available to help diagnose such
+problems. These procedures make use of two arrays called |free| and
+|was_free| that are present only if \MP's debugging routines have
+been included. (You may want to decrease the size of |mem| while you
+@^debugging@>
+are debugging.)
+
+Because |boolean|s are typedef-d as ints, it is better to use
+unsigned chars here.
+
+@<Glob...@>=
+unsigned char *free; /* free cells */
+unsigned char *was_free; /* previously free cells */
+pointer was_mem_end; pointer was_lo_max; pointer was_hi_min;
+ /* previous |mem_end|, |lo_mem_max|,and |hi_mem_min| */
+boolean panicking; /* do we want to check memory constantly? */
+
+@ @<Allocate or initialize ...@>=
+mp->free = xmalloc ((mp->mem_max+1),sizeof (unsigned char));
+mp->was_free = xmalloc ((mp->mem_max+1), sizeof (unsigned char));
+
+@ @<Dealloc variables@>=
+xfree(mp->free);
+xfree(mp->was_free);
+
+@ @<Allocate or ...@>=
+mp->was_hi_min=mp->mem_max;
+mp->panicking=false;
+
+@ @<Declarations@>=
+static void mp_reallocate_memory(MP mp, int l) ;
+
+@ @c
+static void mp_reallocate_memory(MP mp, int l) {
+ XREALLOC(mp->free, l, unsigned char);
+ XREALLOC(mp->was_free, l, unsigned char);
+ if (mp->mem) {
+ int newarea = l-mp->mem_max;
+ XREALLOC(mp->mem, l, memory_word);
+ memset (mp->mem+(mp->mem_max+1),0,sizeof(memory_word)*(newarea));
+ } else {
+ XREALLOC(mp->mem, l, memory_word);
+ memset(mp->mem,0,sizeof(memory_word)*(l+1));
+ }
+ mp->mem_max = l;
+ if (mp->ini_version)
+ mp->mem_top = l;
+}
+
+
+
+@ Procedure |check_mem| makes sure that the available space lists of
+|mem| are well formed, and it optionally prints out all locations
+that are reserved now but were free the last time this procedure was called.
+
+@c
+void mp_check_mem (MP mp,boolean print_locs ) {
+ pointer p,q,r; /* current locations of interest in |mem| */
+ boolean clobbered; /* is something amiss? */
+ for (p=0;p<=mp->lo_mem_max;p++) {
+ mp->free[p]=false; /* you can probably do this faster */
+ }
+ for (p=mp->hi_mem_min;p<= mp->mem_end;p++) {
+ mp->free[p]=false; /* ditto */
+ }
+ @<Check single-word |avail| list@>;
+ @<Check variable-size |avail| list@>;
+ @<Check flags of unavailable nodes@>;
+ @<Check the list of linear dependencies@>;
+ if ( print_locs ) {
+ @<Print newly busy locations@>;
+ }
+ memcpy(mp->was_free,mp->free, sizeof(char)*(mp->mem_end+1));
+ mp->was_mem_end=mp->mem_end;
+ mp->was_lo_max=mp->lo_mem_max;
+ mp->was_hi_min=mp->hi_mem_min;
+}
+
+@ @<Check single-word...@>=
+p=mp->avail; q=null; clobbered=false;
+while ( p!=null ) {
+ if ( (p>mp->mem_end)||(p<mp->hi_mem_min) ) clobbered=true;
+ else if ( mp->free[p] ) clobbered=true;
+ if ( clobbered ) {
+ mp_print_nl(mp, "AVAIL list clobbered at ");
+@.AVAIL list clobbered...@>
+ mp_print_int(mp, q); break;
+ }
+ mp->free[p]=true; q=p; p=mp_link(q);
+}
+
+@ @<Check variable-size...@>=
+p=mp->rover; q=null; clobbered=false;
+do {
+ if ( (p>=mp->lo_mem_max)||(p<0) ) clobbered=true;
+ else if ( (rmp_link(p)>=mp->lo_mem_max)||(rmp_link(p)<0) ) clobbered=true;
+ else if ( !(is_empty(p))||(node_size(p)<2)||
+ (p+node_size(p)>mp->lo_mem_max)|| (lmp_link(rmp_link(p))!=p) ) clobbered=true;
+ if ( clobbered ) {
+ mp_print_nl(mp, "Double-AVAIL list clobbered at ");
+@.Double-AVAIL list clobbered...@>
+ mp_print_int(mp, q); break;
+ }
+ for (q=p;q<=p+node_size(p)-1;q++) { /* mark all locations free */
+ if ( mp->free[q] ) {
+ mp_print_nl(mp, "Doubly free location at ");
+@.Doubly free location...@>
+ mp_print_int(mp, q); break;
+ }
+ mp->free[q]=true;
+ }
+ q=p; p=rmp_link(p);
+} while (p!=mp->rover)
+
+
+@ @<Check flags...@>=
+p=0;
+while ( p<=mp->lo_mem_max ) { /* node |p| should not be empty */
+ if ( is_empty(p) ) {
+ mp_print_nl(mp, "Bad flag at "); mp_print_int(mp, p);
+@.Bad flag...@>
+ }
+ while ( (p<=mp->lo_mem_max) && ! mp->free[p] ) p++;
+ while ( (p<=mp->lo_mem_max) && mp->free[p] ) p++;
+}
+
+@ @<Print newly busy...@>=
+{
+ @<Do intialization required before printing new busy locations@>;
+ mp_print_nl(mp, "New busy locs:");
+@.New busy locs@>
+ for (p=0;p<= mp->lo_mem_max;p++ ) {
+ if ( ! mp->free[p] && ((p>mp->was_lo_max) || mp->was_free[p]) ) {
+ @<Indicate that |p| is a new busy location@>;
+ }
+ }
+ for (p=mp->hi_mem_min;p<=mp->mem_end;p++ ) {
+ if ( ! mp->free[p] &&
+ ((p<mp->was_hi_min) || (p>mp->was_mem_end) || mp->was_free[p]) ) {
+ @<Indicate that |p| is a new busy location@>;
+ }
+ }
+ @<Finish printing new busy locations@>;
+}
+
+@ There might be many new busy locations so we are careful to print contiguous
+blocks compactly. During this operation |q| is the last new busy location and
+|r| is the start of the block containing |q|.
+
+@<Indicate that |p| is a new busy location@>=
+{
+ if ( p>q+1 ) {
+ if ( q>r ) {
+ mp_print(mp, ".."); mp_print_int(mp, q);
+ }
+ mp_print_char(mp, xord(' ')); mp_print_int(mp, p);
+ r=p;
+ }
+ q=p;
+}
+
+@ @<Do intialization required before printing new busy locations@>=
+q=mp->mem_max; r=mp->mem_max
+
+@ @<Finish printing new busy locations@>=
+if ( q>r ) {
+ mp_print(mp, ".."); mp_print_int(mp, q);
+}
+
+@ The |search_mem| procedure attempts to answer the question ``Who points
+to node~|p|?'' In doing so, it fetches |link| and |info| fields of |mem|
+that might not be of type |two_halves|. Strictly speaking, this is
+undefined, and it can lead to ``false drops'' (words that seem to
+point to |p| purely by coincidence). But for debugging purposes, we want
+to rule out the places that do {\sl not\/} point to |p|, so a few false
+drops are tolerable.
+
+@c
+void mp_search_mem (MP mp, pointer p) { /* look for pointers to |p| */
+ integer q; /* current position being searched */
+ for (q=0;q<=mp->lo_mem_max;q++) {
+ if ( mp_link(q)==p ){
+ mp_print_nl(mp, "LINK("); mp_print_int(mp, q); mp_print_char(mp, xord(')'));
+ }
+ if ( mp_info(q)==p ) {
+ mp_print_nl(mp, "INFO("); mp_print_int(mp, q); mp_print_char(mp, xord(')'));
+ }
+ }
+ for (q=mp->hi_mem_min;q<=mp->mem_end;q++) {
+ if ( mp_link(q)==p ) {
+ mp_print_nl(mp, "LINK("); mp_print_int(mp, q); mp_print_char(mp, xord(')'));
+ }
+ if ( mp_info(q)==p ) {
+ mp_print_nl(mp, "INFO("); mp_print_int(mp, q); mp_print_char(mp, xord(')'));
+ }
+ }
+ @<Search |eqtb| for equivalents equal to |p|@>;
+}
+
+@ Just before \.{INIMP} writes out the memory, it sorts the doubly linked
+available space list. The list is probably very short at such times, so a
+simple insertion sort is used. The smallest available location will be
+pointed to by |rover|, the next-smallest by |rmp_link(rover)|, etc.
+
+@<Internal library ...@>=
+void mp_sort_avail (MP mp);
+
+@ @c
+void mp_sort_avail (MP mp) { /* sorts the available variable-size nodes
+ by location */
+ pointer p,q,r; /* indices into |mem| */
+ pointer old_rover; /* initial |rover| setting */
+ p=mp_get_node(mp, 010000000000); /* merge adjacent free areas */
+ p=rmp_link(mp->rover); rmp_link(mp->rover)=max_halfword; old_rover=mp->rover;
+ while ( p!=old_rover ) {
+ @<Sort |p| into the list starting at |rover|
+ and advance |p| to |rmp_link(p)|@>;
+ }
+ p=mp->rover;
+ while ( rmp_link(p)!=max_halfword ) {
+ lmp_link(rmp_link(p))=p; p=rmp_link(p);
+ };
+ rmp_link(p)=mp->rover; lmp_link(mp->rover)=p;
+}
+
+@ The following |while| loop is guaranteed to
+terminate, since the list that starts at
+|rover| ends with |max_halfword| during the sorting procedure.
+
+@<Sort |p|...@>=
+if ( p<mp->rover ) {
+ q=p; p=rmp_link(q); rmp_link(q)=mp->rover; mp->rover=q;
+} else {
+ q=mp->rover;
+ while ( rmp_link(q)<p ) q=rmp_link(q);
+ r=rmp_link(p); rmp_link(p)=rmp_link(q); rmp_link(q)=p; p=r;
+}
+
+
+@* \[12] The command codes.
+Before we can go much further, we need to define symbolic names for the internal
+code numbers that represent the various commands obeyed by \MP. These codes
+are somewhat arbitrary, but not completely so. For example,
+some codes have been made adjacent so that |case| statements in the
+program need not consider cases that are widely spaced, or so that |case|
+statements can be replaced by |if| statements. A command can begin an
+expression if and only if its code lies between |min_primary_command| and
+|max_primary_command|, inclusive. The first token of a statement that doesn't
+begin with an expression has a command code between |min_command| and
+|max_statement_command|, inclusive. Anything less than |min_command| is
+eliminated during macro expansions, and anything no more than |max_pre_command|
+is eliminated when expanding \TeX\ material. Ranges such as
+|min_secondary_command..max_secondary_command| are used when parsing
+expressions, but the relative ordering within such a range is generally not
+critical.
+
+The ordering of the highest-numbered commands
+(|comma<semicolon<end_group<stop|) is crucial for the parsing and
+error-recovery methods of this program as is the ordering |if_test<fi_or_else|
+for the smallest two commands. The ordering is also important in the ranges
+|numeric_token..plus_or_minus| and |left_brace..ampersand|.
+
+At any rate, here is the list, for future reference.
+
+@d start_tex 1 /* begin \TeX\ material (\&{btex}, \&{verbatimtex}) */
+@d etex_marker 2 /* end \TeX\ material (\&{etex}) */
+@d mpx_break 3 /* stop reading an \.{MPX} file (\&{mpxbreak}) */
+@d max_pre_command mpx_break
+@d if_test 4 /* conditional text (\&{if}) */
+@d fi_or_else 5 /* delimiters for conditionals (\&{elseif}, \&{else}, \&{fi}) */
+@d input 6 /* input a source file (\&{input}, \&{endinput}) */
+@d iteration 7 /* iterate (\&{for}, \&{forsuffixes}, \&{forever}, \&{endfor}) */
+@d repeat_loop 8 /* special command substituted for \&{endfor} */
+@d exit_test 9 /* premature exit from a loop (\&{exitif}) */
+@d relax 10 /* do nothing (\.{\char`\\}) */
+@d scan_tokens 11 /* put a string into the input buffer */
+@d expand_after 12 /* look ahead one token */
+@d defined_macro 13 /* a macro defined by the user */
+@d min_command (defined_macro+1)
+@d save_command 14 /* save a list of tokens (\&{save}) */
+@d interim_command 15 /* save an internal quantity (\&{interim}) */
+@d let_command 16 /* redefine a symbolic token (\&{let}) */
+@d new_internal 17 /* define a new internal quantity (\&{newinternal}) */
+@d macro_def 18 /* define a macro (\&{def}, \&{vardef}, etc.) */
+@d ship_out_command 19 /* output a character (\&{shipout}) */
+@d add_to_command 20 /* add to edges (\&{addto}) */
+@d bounds_command 21 /* add bounding path to edges (\&{setbounds}, \&{clip}) */
+@d tfm_command 22 /* command for font metric info (\&{ligtable}, etc.) */
+@d protection_command 23 /* set protection flag (\&{outer}, \&{inner}) */
+@d show_command 24 /* diagnostic output (\&{show}, \&{showvariable}, etc.) */
+@d mode_command 25 /* set interaction level (\&{batchmode}, etc.) */
+@d mp_random_seed 26 /* initialize random number generator (\&{randomseed}) */
+@d message_command 27 /* communicate to user (\&{message}, \&{errmessage}) */
+@d every_job_command 28 /* designate a starting token (\&{everyjob}) */
+@d delimiters 29 /* define a pair of delimiters (\&{delimiters}) */
+@d special_command 30 /* output special info (\&{special})
+ or font map info (\&{fontmapfile}, \&{fontmapline}) */
+@d write_command 31 /* write text to a file (\&{write}) */
+@d type_name 32 /* declare a type (\&{numeric}, \&{pair}, etc.) */
+@d max_statement_command type_name
+@d min_primary_command type_name
+@d left_delimiter 33 /* the left delimiter of a matching pair */
+@d begin_group 34 /* beginning of a group (\&{begingroup}) */
+@d nullary 35 /* an operator without arguments (e.g., \&{normaldeviate}) */
+@d unary 36 /* an operator with one argument (e.g., \&{sqrt}) */
+@d str_op 37 /* convert a suffix to a string (\&{str}) */
+@d cycle 38 /* close a cyclic path (\&{cycle}) */
+@d primary_binary 39 /* binary operation taking `\&{of}' (e.g., \&{point}) */
+@d capsule_token 40 /* a value that has been put into a token list */
+@d string_token 41 /* a string constant (e.g., |"hello"|) */
+@d internal_quantity 42 /* internal numeric parameter (e.g., \&{pausing}) */
+@d min_suffix_token internal_quantity
+@d tag_token 43 /* a symbolic token without a primitive meaning */
+@d numeric_token 44 /* a numeric constant (e.g., \.{3.14159}) */
+@d max_suffix_token numeric_token
+@d plus_or_minus 45 /* either `\.+' or `\.-' */
+@d max_primary_command plus_or_minus /* should also be |numeric_token+1| */
+@d min_tertiary_command plus_or_minus
+@d tertiary_secondary_macro 46 /* a macro defined by \&{secondarydef} */
+@d tertiary_binary 47 /* an operator at the tertiary level (e.g., `\.{++}') */
+@d max_tertiary_command tertiary_binary
+@d left_brace 48 /* the operator `\.{\char`\{}' */
+@d min_expression_command left_brace
+@d path_join 49 /* the operator `\.{..}' */
+@d ampersand 50 /* the operator `\.\&' */
+@d expression_tertiary_macro 51 /* a macro defined by \&{tertiarydef} */
+@d expression_binary 52 /* an operator at the expression level (e.g., `\.<') */
+@d equals 53 /* the operator `\.=' */
+@d max_expression_command equals
+@d and_command 54 /* the operator `\&{and}' */
+@d min_secondary_command and_command
+@d secondary_primary_macro 55 /* a macro defined by \&{primarydef} */
+@d slash 56 /* the operator `\./' */
+@d secondary_binary 57 /* an operator at the binary level (e.g., \&{shifted}) */
+@d max_secondary_command secondary_binary
+@d param_type 58 /* type of parameter (\&{primary}, \&{expr}, \&{suffix}, etc.) */
+@d controls 59 /* specify control points explicitly (\&{controls}) */
+@d tension 60 /* specify tension between knots (\&{tension}) */
+@d at_least 61 /* bounded tension value (\&{atleast}) */
+@d curl_command 62 /* specify curl at an end knot (\&{curl}) */
+@d macro_special 63 /* special macro operators (\&{quote}, \.{\#\AT!}, etc.) */
+@d right_delimiter 64 /* the right delimiter of a matching pair */
+@d left_bracket 65 /* the operator `\.[' */
+@d right_bracket 66 /* the operator `\.]' */
+@d right_brace 67 /* the operator `\.{\char`\}}' */
+@d with_option 68 /* option for filling (\&{withpen}, \&{withweight}, etc.) */
+@d thing_to_add 69
+ /* variant of \&{addto} (\&{contour}, \&{doublepath}, \&{also}) */
+@d of_token 70 /* the operator `\&{of}' */
+@d to_token 71 /* the operator `\&{to}' */
+@d step_token 72 /* the operator `\&{step}' */
+@d until_token 73 /* the operator `\&{until}' */
+@d within_token 74 /* the operator `\&{within}' */
+@d lig_kern_token 75
+ /* the operators `\&{kern}' and `\.{=:}' and `\.{=:\char'174}', etc. */
+@d assignment 76 /* the operator `\.{:=}' */
+@d skip_to 77 /* the operation `\&{skipto}' */
+@d bchar_label 78 /* the operator `\.{\char'174\char'174:}' */
+@d double_colon 79 /* the operator `\.{::}' */
+@d colon 80 /* the operator `\.:' */
+@#
+@d comma 81 /* the operator `\.,', must be |colon+1| */
+@d end_of_statement (mp->cur_cmd>comma)
+@d semicolon 82 /* the operator `\.;', must be |comma+1| */
+@d end_group 83 /* end a group (\&{endgroup}), must be |semicolon+1| */
+@d stop 84 /* end a job (\&{end}, \&{dump}), must be |end_group+1| */
+@d max_command_code stop
+@d outer_tag (max_command_code+1) /* protection code added to command code */
+
+@<Types...@>=
+typedef int command_code;
+
+@ Variables and capsules in \MP\ have a variety of ``types,''
+distinguished by the code numbers defined here. These numbers are also
+not completely arbitrary. Things that get expanded must have types
+|>mp_independent|; a type remaining after expansion is numeric if and only if
+its code number is at least |numeric_type|; objects containing numeric
+parts must have types between |transform_type| and |pair_type|;
+all other types must be smaller than |transform_type|; and among the types
+that are not unknown or vacuous, the smallest two must be |boolean_type|
+and |string_type| in that order.
+
+@d undefined 0 /* no type has been declared */
+@d unknown_tag 1 /* this constant is added to certain type codes below */
+@d unknown_types mp_unknown_boolean: case mp_unknown_string:
+ case mp_unknown_pen: case mp_unknown_picture: case mp_unknown_path
+
+@<Types...@>=
+enum mp_variable_type {
+mp_vacuous=1, /* no expression was present */
+mp_boolean_type, /* \&{boolean} with a known value */
+mp_unknown_boolean,
+mp_string_type, /* \&{string} with a known value */
+mp_unknown_string,
+mp_pen_type, /* \&{pen} with a known value */
+mp_unknown_pen,
+mp_path_type, /* \&{path} with a known value */
+mp_unknown_path,
+mp_picture_type, /* \&{picture} with a known value */
+mp_unknown_picture,
+mp_transform_type, /* \&{transform} variable or capsule */
+mp_color_type, /* \&{color} variable or capsule */
+mp_cmykcolor_type, /* \&{cmykcolor} variable or capsule */
+mp_pair_type, /* \&{pair} variable or capsule */
+mp_numeric_type, /* variable that has been declared \&{numeric} but not used */
+mp_known, /* \&{numeric} with a known value */
+mp_dependent, /* a linear combination with |fraction| coefficients */
+mp_proto_dependent, /* a linear combination with |scaled| coefficients */
+mp_independent, /* \&{numeric} with unknown value */
+mp_token_list, /* variable name or suffix argument or text argument */
+mp_structured, /* variable with subscripts and attributes */
+mp_unsuffixed_macro, /* variable defined with \&{vardef} but no \.{\AT!\#} */
+mp_suffixed_macro /* variable defined with \&{vardef} and \.{\AT!\#} */
+} ;
+
+@ @<Declarations@>=
+static void mp_print_type (MP mp,quarterword t) ;
+
+@ @<Basic printing procedures@>=
+void mp_print_type (MP mp,quarterword t) {
+ switch (t) {
+ case mp_vacuous:mp_print(mp, "mp_vacuous"); break;
+ case mp_boolean_type:mp_print(mp, "boolean"); break;
+ case mp_unknown_boolean:mp_print(mp, "unknown boolean"); break;
+ case mp_string_type:mp_print(mp, "string"); break;
+ case mp_unknown_string:mp_print(mp, "unknown string"); break;
+ case mp_pen_type:mp_print(mp, "pen"); break;
+ case mp_unknown_pen:mp_print(mp, "unknown pen"); break;
+ case mp_path_type:mp_print(mp, "path"); break;
+ case mp_unknown_path:mp_print(mp, "unknown path"); break;
+ case mp_picture_type:mp_print(mp, "picture"); break;
+ case mp_unknown_picture:mp_print(mp, "unknown picture"); break;
+ case mp_transform_type:mp_print(mp, "transform"); break;
+ case mp_color_type:mp_print(mp, "color"); break;
+ case mp_cmykcolor_type:mp_print(mp, "cmykcolor"); break;
+ case mp_pair_type:mp_print(mp, "pair"); break;
+ case mp_known:mp_print(mp, "known numeric"); break;
+ case mp_dependent:mp_print(mp, "dependent"); break;
+ case mp_proto_dependent:mp_print(mp, "proto-dependent"); break;
+ case mp_numeric_type:mp_print(mp, "numeric"); break;
+ case mp_independent:mp_print(mp, "independent"); break;
+ case mp_token_list:mp_print(mp, "token list"); break;
+ case mp_structured:mp_print(mp, "mp_structured"); break;
+ case mp_unsuffixed_macro:mp_print(mp, "unsuffixed macro"); break;
+ case mp_suffixed_macro:mp_print(mp, "suffixed macro"); break;
+ default: mp_print(mp, "undefined"); break;
+ }
+}
+
+@ Values inside \MP\ are stored in two-word nodes that have a |name_type|
+as well as a |type|. The possibilities for |name_type| are defined
+here; they will be explained in more detail later.
+
+@<Types...@>=
+enum mp_name_types {
+ mp_root=0, /* |name_type| at the top level of a variable */
+ mp_saved_root, /* same, when the variable has been saved */
+ mp_structured_root, /* |name_type| where a |mp_structured| branch occurs */
+ mp_subscr, /* |name_type| in a subscript node */
+ mp_attr, /* |name_type| in an attribute node */
+ mp_x_part_sector, /* |name_type| in the \&{xpart} of a node */
+ mp_y_part_sector, /* |name_type| in the \&{ypart} of a node */
+ mp_xx_part_sector, /* |name_type| in the \&{xxpart} of a node */
+ mp_xy_part_sector, /* |name_type| in the \&{xypart} of a node */
+ mp_yx_part_sector, /* |name_type| in the \&{yxpart} of a node */
+ mp_yy_part_sector, /* |name_type| in the \&{yypart} of a node */
+ mp_red_part_sector, /* |name_type| in the \&{redpart} of a node */
+ mp_green_part_sector, /* |name_type| in the \&{greenpart} of a node */
+ mp_blue_part_sector, /* |name_type| in the \&{bluepart} of a node */
+ mp_cyan_part_sector, /* |name_type| in the \&{redpart} of a node */
+ mp_magenta_part_sector, /* |name_type| in the \&{greenpart} of a node */
+ mp_yellow_part_sector, /* |name_type| in the \&{bluepart} of a node */
+ mp_black_part_sector, /* |name_type| in the \&{greenpart} of a node */
+ mp_grey_part_sector, /* |name_type| in the \&{bluepart} of a node */
+ mp_capsule, /* |name_type| in stashed-away subexpressions */
+ mp_token /* |name_type| in a numeric token or string token */
+};
+
+@ Primitive operations that produce values have a secondary identification
+code in addition to their command code; it's something like genera and species.
+For example, `\.*' has the command code |primary_binary|, and its
+secondary identification is |times|. The secondary codes start at 30 so that
+they don't overlap with the type codes; some type codes (e.g., |mp_string_type|)
+are used as operators as well as type identifications. The relative values
+are not critical, except for |true_code..false_code|, |or_op..and_op|,
+and |filled_op..bounded_op|. The restrictions are that
+|and_op-false_code=or_op-true_code|, that the ordering of
+|x_part...blue_part| must match that of |x_part_sector..mp_blue_part_sector|,
+and the ordering of |filled_op..bounded_op| must match that of the code
+values they test for.
+
+@d true_code 30 /* operation code for \.{true} */
+@d false_code 31 /* operation code for \.{false} */
+@d null_picture_code 32 /* operation code for \.{nullpicture} */
+@d null_pen_code 33 /* operation code for \.{nullpen} */
+@d job_name_op 34 /* operation code for \.{jobname} */
+@d read_string_op 35 /* operation code for \.{readstring} */
+@d pen_circle 36 /* operation code for \.{pencircle} */
+@d normal_deviate 37 /* operation code for \.{normaldeviate} */
+@d read_from_op 38 /* operation code for \.{readfrom} */
+@d close_from_op 39 /* operation code for \.{closefrom} */
+@d odd_op 40 /* operation code for \.{odd} */
+@d known_op 41 /* operation code for \.{known} */
+@d unknown_op 42 /* operation code for \.{unknown} */
+@d not_op 43 /* operation code for \.{not} */
+@d decimal 44 /* operation code for \.{decimal} */
+@d reverse 45 /* operation code for \.{reverse} */
+@d make_path_op 46 /* operation code for \.{makepath} */
+@d make_pen_op 47 /* operation code for \.{makepen} */
+@d oct_op 48 /* operation code for \.{oct} */
+@d hex_op 49 /* operation code for \.{hex} */
+@d ASCII_op 50 /* operation code for \.{ASCII} */
+@d char_op 51 /* operation code for \.{char} */
+@d length_op 52 /* operation code for \.{length} */
+@d turning_op 53 /* operation code for \.{turningnumber} */
+@d color_model_part 54 /* operation code for \.{colormodel} */
+@d x_part 55 /* operation code for \.{xpart} */
+@d y_part 56 /* operation code for \.{ypart} */
+@d xx_part 57 /* operation code for \.{xxpart} */
+@d xy_part 58 /* operation code for \.{xypart} */
+@d yx_part 59 /* operation code for \.{yxpart} */
+@d yy_part 60 /* operation code for \.{yypart} */
+@d red_part 61 /* operation code for \.{redpart} */
+@d green_part 62 /* operation code for \.{greenpart} */
+@d blue_part 63 /* operation code for \.{bluepart} */
+@d cyan_part 64 /* operation code for \.{cyanpart} */
+@d magenta_part 65 /* operation code for \.{magentapart} */
+@d yellow_part 66 /* operation code for \.{yellowpart} */
+@d black_part 67 /* operation code for \.{blackpart} */
+@d grey_part 68 /* operation code for \.{greypart} */
+@d font_part 69 /* operation code for \.{fontpart} */
+@d text_part 70 /* operation code for \.{textpart} */
+@d path_part 71 /* operation code for \.{pathpart} */
+@d pen_part 72 /* operation code for \.{penpart} */
+@d dash_part 73 /* operation code for \.{dashpart} */
+@d sqrt_op 74 /* operation code for \.{sqrt} */
+@d mp_m_exp_op 75 /* operation code for \.{mexp} */
+@d mp_m_log_op 76 /* operation code for \.{mlog} */
+@d sin_d_op 77 /* operation code for \.{sind} */
+@d cos_d_op 78 /* operation code for \.{cosd} */
+@d floor_op 79 /* operation code for \.{floor} */
+@d uniform_deviate 80 /* operation code for \.{uniformdeviate} */
+@d char_exists_op 81 /* operation code for \.{charexists} */
+@d font_size 82 /* operation code for \.{fontsize} */
+@d ll_corner_op 83 /* operation code for \.{llcorner} */
+@d lr_corner_op 84 /* operation code for \.{lrcorner} */
+@d ul_corner_op 85 /* operation code for \.{ulcorner} */
+@d ur_corner_op 86 /* operation code for \.{urcorner} */
+@d arc_length 87 /* operation code for \.{arclength} */
+@d angle_op 88 /* operation code for \.{angle} */
+@d cycle_op 89 /* operation code for \.{cycle} */
+@d filled_op 90 /* operation code for \.{filled} */
+@d stroked_op 91 /* operation code for \.{stroked} */
+@d textual_op 92 /* operation code for \.{textual} */
+@d clipped_op 93 /* operation code for \.{clipped} */
+@d bounded_op 94 /* operation code for \.{bounded} */
+@d plus 95 /* operation code for \.+ */
+@d minus 96 /* operation code for \.- */
+@d times 97 /* operation code for \.* */
+@d over 98 /* operation code for \./ */
+@d pythag_add 99 /* operation code for \.{++} */
+@d pythag_sub 100 /* operation code for \.{+-+} */
+@d or_op 101 /* operation code for \.{or} */
+@d and_op 102 /* operation code for \.{and} */
+@d less_than 103 /* operation code for \.< */
+@d less_or_equal 104 /* operation code for \.{<=} */
+@d greater_than 105 /* operation code for \.> */
+@d greater_or_equal 106 /* operation code for \.{>=} */
+@d equal_to 107 /* operation code for \.= */
+@d unequal_to 108 /* operation code for \.{<>} */
+@d concatenate 109 /* operation code for \.\& */
+@d rotated_by 110 /* operation code for \.{rotated} */
+@d slanted_by 111 /* operation code for \.{slanted} */
+@d scaled_by 112 /* operation code for \.{scaled} */
+@d shifted_by 113 /* operation code for \.{shifted} */
+@d transformed_by 114 /* operation code for \.{transformed} */
+@d x_scaled 115 /* operation code for \.{xscaled} */
+@d y_scaled 116 /* operation code for \.{yscaled} */
+@d z_scaled 117 /* operation code for \.{zscaled} */
+@d in_font 118 /* operation code for \.{infont} */
+@d intersect 119 /* operation code for \.{intersectiontimes} */
+@d double_dot 120 /* operation code for improper \.{..} */
+@d substring_of 121 /* operation code for \.{substring} */
+@d min_of substring_of
+@d subpath_of 122 /* operation code for \.{subpath} */
+@d direction_time_of 123 /* operation code for \.{directiontime} */
+@d point_of 124 /* operation code for \.{point} */
+@d precontrol_of 125 /* operation code for \.{precontrol} */
+@d postcontrol_of 126 /* operation code for \.{postcontrol} */
+@d pen_offset_of 127 /* operation code for \.{penoffset} */
+@d arc_time_of 128 /* operation code for \.{arctime} */
+@d mp_version 129 /* operation code for \.{mpversion} */
+@d envelope_of 130 /* operation code for \.{envelope} */
+
+@c static void mp_print_op (MP mp,quarterword c) {
+ if (c<=mp_numeric_type ) {
+ mp_print_type(mp, c);
+ } else {
+ switch (c) {
+ case true_code:mp_print(mp, "true"); break;
+ case false_code:mp_print(mp, "false"); break;
+ case null_picture_code:mp_print(mp, "nullpicture"); break;
+ case null_pen_code:mp_print(mp, "nullpen"); break;
+ case job_name_op:mp_print(mp, "jobname"); break;
+ case read_string_op:mp_print(mp, "readstring"); break;
+ case pen_circle:mp_print(mp, "pencircle"); break;
+ case normal_deviate:mp_print(mp, "normaldeviate"); break;
+ case read_from_op:mp_print(mp, "readfrom"); break;
+ case close_from_op:mp_print(mp, "closefrom"); break;
+ case odd_op:mp_print(mp, "odd"); break;
+ case known_op:mp_print(mp, "known"); break;
+ case unknown_op:mp_print(mp, "unknown"); break;
+ case not_op:mp_print(mp, "not"); break;
+ case decimal:mp_print(mp, "decimal"); break;
+ case reverse:mp_print(mp, "reverse"); break;
+ case make_path_op:mp_print(mp, "makepath"); break;
+ case make_pen_op:mp_print(mp, "makepen"); break;
+ case oct_op:mp_print(mp, "oct"); break;
+ case hex_op:mp_print(mp, "hex"); break;
+ case ASCII_op:mp_print(mp, "ASCII"); break;
+ case char_op:mp_print(mp, "char"); break;
+ case length_op:mp_print(mp, "length"); break;
+ case turning_op:mp_print(mp, "turningnumber"); break;
+ case x_part:mp_print(mp, "xpart"); break;
+ case y_part:mp_print(mp, "ypart"); break;
+ case xx_part:mp_print(mp, "xxpart"); break;
+ case xy_part:mp_print(mp, "xypart"); break;
+ case yx_part:mp_print(mp, "yxpart"); break;
+ case yy_part:mp_print(mp, "yypart"); break;
+ case red_part:mp_print(mp, "redpart"); break;
+ case green_part:mp_print(mp, "greenpart"); break;
+ case blue_part:mp_print(mp, "bluepart"); break;
+ case cyan_part:mp_print(mp, "cyanpart"); break;
+ case magenta_part:mp_print(mp, "magentapart"); break;
+ case yellow_part:mp_print(mp, "yellowpart"); break;
+ case black_part:mp_print(mp, "blackpart"); break;
+ case grey_part:mp_print(mp, "greypart"); break;
+ case color_model_part:mp_print(mp, "colormodel"); break;
+ case font_part:mp_print(mp, "fontpart"); break;
+ case text_part:mp_print(mp, "textpart"); break;
+ case path_part:mp_print(mp, "pathpart"); break;
+ case pen_part:mp_print(mp, "penpart"); break;
+ case dash_part:mp_print(mp, "dashpart"); break;
+ case sqrt_op:mp_print(mp, "sqrt"); break;
+ case mp_m_exp_op:mp_print(mp, "mexp"); break;
+ case mp_m_log_op:mp_print(mp, "mlog"); break;
+ case sin_d_op:mp_print(mp, "sind"); break;
+ case cos_d_op:mp_print(mp, "cosd"); break;
+ case floor_op:mp_print(mp, "floor"); break;
+ case uniform_deviate:mp_print(mp, "uniformdeviate"); break;
+ case char_exists_op:mp_print(mp, "charexists"); break;
+ case font_size:mp_print(mp, "fontsize"); break;
+ case ll_corner_op:mp_print(mp, "llcorner"); break;
+ case lr_corner_op:mp_print(mp, "lrcorner"); break;
+ case ul_corner_op:mp_print(mp, "ulcorner"); break;
+ case ur_corner_op:mp_print(mp, "urcorner"); break;
+ case arc_length:mp_print(mp, "arclength"); break;
+ case angle_op:mp_print(mp, "angle"); break;
+ case cycle_op:mp_print(mp, "cycle"); break;
+ case filled_op:mp_print(mp, "filled"); break;
+ case stroked_op:mp_print(mp, "stroked"); break;
+ case textual_op:mp_print(mp, "textual"); break;
+ case clipped_op:mp_print(mp, "clipped"); break;
+ case bounded_op:mp_print(mp, "bounded"); break;
+ case plus:mp_print_char(mp, xord('+')); break;
+ case minus:mp_print_char(mp, xord('-')); break;
+ case times:mp_print_char(mp, xord('*')); break;
+ case over:mp_print_char(mp, xord('/')); break;
+ case pythag_add:mp_print(mp, "++"); break;
+ case pythag_sub:mp_print(mp, "+-+"); break;
+ case or_op:mp_print(mp, "or"); break;
+ case and_op:mp_print(mp, "and"); break;
+ case less_than:mp_print_char(mp, xord('<')); break;
+ case less_or_equal:mp_print(mp, "<="); break;
+ case greater_than:mp_print_char(mp, xord('>')); break;
+ case greater_or_equal:mp_print(mp, ">="); break;
+ case equal_to:mp_print_char(mp, xord('=')); break;
+ case unequal_to:mp_print(mp, "<>"); break;
+ case concatenate:mp_print(mp, "&"); break;
+ case rotated_by:mp_print(mp, "rotated"); break;
+ case slanted_by:mp_print(mp, "slanted"); break;
+ case scaled_by:mp_print(mp, "scaled"); break;
+ case shifted_by:mp_print(mp, "shifted"); break;
+ case transformed_by:mp_print(mp, "transformed"); break;
+ case x_scaled:mp_print(mp, "xscaled"); break;
+ case y_scaled:mp_print(mp, "yscaled"); break;
+ case z_scaled:mp_print(mp, "zscaled"); break;
+ case in_font:mp_print(mp, "infont"); break;
+ case intersect:mp_print(mp, "intersectiontimes"); break;
+ case substring_of:mp_print(mp, "substring"); break;
+ case subpath_of:mp_print(mp, "subpath"); break;
+ case direction_time_of:mp_print(mp, "directiontime"); break;
+ case point_of:mp_print(mp, "point"); break;
+ case precontrol_of:mp_print(mp, "precontrol"); break;
+ case postcontrol_of:mp_print(mp, "postcontrol"); break;
+ case pen_offset_of:mp_print(mp, "penoffset"); break;
+ case arc_time_of:mp_print(mp, "arctime"); break;
+ case mp_version:mp_print(mp, "mpversion"); break;
+ case envelope_of:mp_print(mp, "envelope"); break;
+ default: mp_print(mp, ".."); break;
+ }
+ }
+}
+
+@ \MP\ also has a bunch of internal parameters that a user might want to
+fuss with. Every such parameter has an identifying code number, defined here.
+
+@<Types...@>=
+enum mp_given_internal {
+ mp_output_template=1, /* a string set up by \&{outputtemplate} */
+ mp_output_format, /* the output format set up by \&{outputformat} */
+ mp_tracing_titles, /* show titles online when they appear */
+ mp_tracing_equations, /* show each variable when it becomes known */
+ mp_tracing_capsules, /* show capsules too */
+ mp_tracing_choices, /* show the control points chosen for paths */
+ mp_tracing_specs, /* show path subdivision prior to filling with polygonal a pen */
+ mp_tracing_commands, /* show commands and operations before they are performed */
+ mp_tracing_restores, /* show when a variable or internal is restored */
+ mp_tracing_macros, /* show macros before they are expanded */
+ mp_tracing_output, /* show digitized edges as they are output */
+ mp_tracing_stats, /* show memory usage at end of job */
+ mp_tracing_lost_chars, /* show characters that aren't \&{infont} */
+ mp_tracing_online, /* show long diagnostics on terminal and in the log file */
+ mp_year, /* the current year (e.g., 1984) */
+ mp_month, /* the current month (e.g., 3 $\equiv$ March) */
+ mp_day, /* the current day of the month */
+ mp_time, /* the number of minutes past midnight when this job started */
+ mp_char_code, /* the number of the next character to be output */
+ mp_char_ext, /* the extension code of the next character to be output */
+ mp_char_wd, /* the width of the next character to be output */
+ mp_char_ht, /* the height of the next character to be output */
+ mp_char_dp, /* the depth of the next character to be output */
+ mp_char_ic, /* the italic correction of the next character to be output */
+ mp_design_size, /* the unit of measure used for |mp_char_wd..mp_char_ic|, in points */
+ mp_pausing, /* positive to display lines on the terminal before they are read */
+ mp_showstopping, /* positive to stop after each \&{show} command */
+ mp_fontmaking, /* positive if font metric output is to be produced */
+ mp_linejoin, /* as in \ps: 0 for mitered, 1 for round, 2 for beveled */
+ mp_linecap, /* as in \ps: 0 for butt, 1 for round, 2 for square */
+ mp_miterlimit, /* controls miter length as in \ps */
+ mp_warning_check, /* controls error message when variable value is large */
+ mp_boundary_char, /* the right boundary character for ligatures */
+ mp_prologues, /* positive to output conforming PostScript using built-in fonts */
+ mp_true_corners, /* positive to make \&{llcorner} etc. ignore \&{setbounds} */
+ mp_default_color_model, /* the default color model for unspecified items */
+ mp_restore_clip_color,
+ mp_procset, /* wether or not create PostScript command shortcuts */
+ mp_gtroffmode /* whether the user specified |-troff| on the command line */
+};
+
+@
+
+@d max_given_internal mp_gtroffmode
+
+@<Glob...@>=
+scaled *internal; /* the values of internal quantities */
+char **int_name; /* their names */
+int int_ptr; /* the maximum internal quantity defined so far */
+int max_internal; /* current maximum number of internal quantities */
+
+@ @<Option variables@>=
+int troff_mode;
+
+@ @<Allocate or initialize ...@>=
+mp->max_internal=2*max_given_internal;
+mp->internal = xmalloc ((mp->max_internal+1), sizeof(scaled));
+memset(mp->internal,0,(mp->max_internal+1)* sizeof(scaled));
+mp->int_name = xmalloc ((mp->max_internal+1), sizeof(char *));
+memset(mp->int_name,0,(mp->max_internal+1) * sizeof(char *));
+mp->troff_mode=(opt->troff_mode>0 ? true : false);
+
+@ @<Exported function ...@>=
+int mp_troff_mode(MP mp);
+
+@ @c
+int mp_troff_mode(MP mp) { return mp->troff_mode; }
+
+@ @<Set initial ...@>=
+mp->int_ptr=max_given_internal;
+
+@ The symbolic names for internal quantities are put into \MP's hash table
+by using a routine called |primitive|, which will be defined later. Let us
+enter them now, so that we don't have to list all those names again
+anywhere else.
+
+@<Put each of \MP's primitives into the hash table@>=
+mp_primitive(mp, "tracingtitles",internal_quantity,mp_tracing_titles);
+@:tracingtitles_}{\&{tracingtitles} primitive@>
+mp_primitive(mp, "tracingequations",internal_quantity,mp_tracing_equations);
+@:mp_tracing_equations_}{\&{tracingequations} primitive@>
+mp_primitive(mp, "tracingcapsules",internal_quantity,mp_tracing_capsules);
+@:mp_tracing_capsules_}{\&{tracingcapsules} primitive@>
+mp_primitive(mp, "tracingchoices",internal_quantity,mp_tracing_choices);
+@:mp_tracing_choices_}{\&{tracingchoices} primitive@>
+mp_primitive(mp, "tracingspecs",internal_quantity,mp_tracing_specs);
+@:mp_tracing_specs_}{\&{tracingspecs} primitive@>
+mp_primitive(mp, "tracingcommands",internal_quantity,mp_tracing_commands);
+@:mp_tracing_commands_}{\&{tracingcommands} primitive@>
+mp_primitive(mp, "tracingrestores",internal_quantity,mp_tracing_restores);
+@:mp_tracing_restores_}{\&{tracingrestores} primitive@>
+mp_primitive(mp, "tracingmacros",internal_quantity,mp_tracing_macros);
+@:mp_tracing_macros_}{\&{tracingmacros} primitive@>
+mp_primitive(mp, "tracingoutput",internal_quantity,mp_tracing_output);
+@:mp_tracing_output_}{\&{tracingoutput} primitive@>
+mp_primitive(mp, "tracingstats",internal_quantity,mp_tracing_stats);
+@:mp_tracing_stats_}{\&{tracingstats} primitive@>
+mp_primitive(mp, "tracinglostchars",internal_quantity,mp_tracing_lost_chars);
+@:mp_tracing_lost_chars_}{\&{tracinglostchars} primitive@>
+mp_primitive(mp, "tracingonline",internal_quantity,mp_tracing_online);
+@:mp_tracing_online_}{\&{tracingonline} primitive@>
+mp_primitive(mp, "year",internal_quantity,mp_year);
+@:mp_year_}{\&{year} primitive@>
+mp_primitive(mp, "month",internal_quantity,mp_month);
+@:mp_month_}{\&{month} primitive@>
+mp_primitive(mp, "day",internal_quantity,mp_day);
+@:mp_day_}{\&{day} primitive@>
+mp_primitive(mp, "time",internal_quantity,mp_time);
+@:time_}{\&{time} primitive@>
+mp_primitive(mp, "charcode",internal_quantity,mp_char_code);
+@:mp_char_code_}{\&{charcode} primitive@>
+mp_primitive(mp, "charext",internal_quantity,mp_char_ext);
+@:mp_char_ext_}{\&{charext} primitive@>
+mp_primitive(mp, "charwd",internal_quantity,mp_char_wd);
+@:mp_char_wd_}{\&{charwd} primitive@>
+mp_primitive(mp, "charht",internal_quantity,mp_char_ht);
+@:mp_char_ht_}{\&{charht} primitive@>
+mp_primitive(mp, "chardp",internal_quantity,mp_char_dp);
+@:mp_char_dp_}{\&{chardp} primitive@>
+mp_primitive(mp, "charic",internal_quantity,mp_char_ic);
+@:mp_char_ic_}{\&{charic} primitive@>
+mp_primitive(mp, "designsize",internal_quantity,mp_design_size);
+@:mp_design_size_}{\&{designsize} primitive@>
+mp_primitive(mp, "pausing",internal_quantity,mp_pausing);
+@:mp_pausing_}{\&{pausing} primitive@>
+mp_primitive(mp, "showstopping",internal_quantity,mp_showstopping);
+@:mp_showstopping_}{\&{showstopping} primitive@>
+mp_primitive(mp, "fontmaking",internal_quantity,mp_fontmaking);
+@:mp_fontmaking_}{\&{fontmaking} primitive@>
+mp_primitive(mp, "linejoin",internal_quantity,mp_linejoin);
+@:mp_linejoin_}{\&{linejoin} primitive@>
+mp_primitive(mp, "linecap",internal_quantity,mp_linecap);
+@:mp_linecap_}{\&{linecap} primitive@>
+mp_primitive(mp, "miterlimit",internal_quantity,mp_miterlimit);
+@:mp_miterlimit_}{\&{miterlimit} primitive@>
+mp_primitive(mp, "warningcheck",internal_quantity,mp_warning_check);
+@:mp_warning_check_}{\&{warningcheck} primitive@>
+mp_primitive(mp, "boundarychar",internal_quantity,mp_boundary_char);
+@:mp_boundary_char_}{\&{boundarychar} primitive@>
+mp_primitive(mp, "prologues",internal_quantity,mp_prologues);
+@:mp_prologues_}{\&{prologues} primitive@>
+mp_primitive(mp, "truecorners",internal_quantity,mp_true_corners);
+@:mp_true_corners_}{\&{truecorners} primitive@>
+mp_primitive(mp, "mpprocset",internal_quantity,mp_procset);
+@:mp_procset_}{\&{mpprocset} primitive@>
+mp_primitive(mp, "troffmode",internal_quantity,mp_gtroffmode);
+@:troffmode_}{\&{troffmode} primitive@>
+mp_primitive(mp, "defaultcolormodel",internal_quantity,mp_default_color_model);
+@:mp_default_color_model_}{\&{defaultcolormodel} primitive@>
+mp_primitive(mp, "restoreclipcolor",internal_quantity,mp_restore_clip_color);
+@:mp_restore_clip_color_}{\&{restoreclipcolor} primitive@>
+mp_primitive(mp, "outputtemplate",internal_quantity,mp_output_template);
+@:mp_output_template_}{\&{outputtemplate} primitive@>
+mp_primitive(mp, "outputformat",internal_quantity,mp_output_format);
+@:mp_output_format_}{\&{outputformat} primitive@>
+
+@ Colors can be specified in four color models. In the special
+case of |no_model|, MetaPost does not output any color operator to
+the postscript output.
+
+Note: these values are passed directly on to |with_option|. This only
+works because the other possible values passed to |with_option| are
+8 and 10 respectively (from |with_pen| and |with_picture|).
+
+There is a first state, that is only used for |gs_colormodel|. It flags
+the fact that there has not been any kind of color specification by
+the user so far in the game.
+
+@(mplib.h@>=
+enum mp_color_model {
+ mp_no_model=1,
+ mp_grey_model=3,
+ mp_rgb_model=5,
+ mp_cmyk_model=7,
+ mp_uninitialized_model=9
+};
+
+
+@ @<Initialize table entries (done by \.{INIMP} only)@>=
+mp->internal[mp_default_color_model]=(mp_rgb_model*unity);
+mp->internal[mp_restore_clip_color]=unity;
+mp->internal[mp_output_template]=intern("%j.%c");
+mp->internal[mp_output_format]=intern("eps");
+
+@ Well, we do have to list the names one more time, for use in symbolic
+printouts.
+
+@<Initialize table...@>=
+mp->int_name[mp_tracing_titles]=xstrdup("tracingtitles");
+mp->int_name[mp_tracing_equations]=xstrdup("tracingequations");
+mp->int_name[mp_tracing_capsules]=xstrdup("tracingcapsules");
+mp->int_name[mp_tracing_choices]=xstrdup("tracingchoices");
+mp->int_name[mp_tracing_specs]=xstrdup("tracingspecs");
+mp->int_name[mp_tracing_commands]=xstrdup("tracingcommands");
+mp->int_name[mp_tracing_restores]=xstrdup("tracingrestores");
+mp->int_name[mp_tracing_macros]=xstrdup("tracingmacros");
+mp->int_name[mp_tracing_output]=xstrdup("tracingoutput");
+mp->int_name[mp_tracing_stats]=xstrdup("tracingstats");
+mp->int_name[mp_tracing_lost_chars]=xstrdup("tracinglostchars");
+mp->int_name[mp_tracing_online]=xstrdup("tracingonline");
+mp->int_name[mp_year]=xstrdup("year");
+mp->int_name[mp_month]=xstrdup("month");
+mp->int_name[mp_day]=xstrdup("day");
+mp->int_name[mp_time]=xstrdup("time");
+mp->int_name[mp_char_code]=xstrdup("charcode");
+mp->int_name[mp_char_ext]=xstrdup("charext");
+mp->int_name[mp_char_wd]=xstrdup("charwd");
+mp->int_name[mp_char_ht]=xstrdup("charht");
+mp->int_name[mp_char_dp]=xstrdup("chardp");
+mp->int_name[mp_char_ic]=xstrdup("charic");
+mp->int_name[mp_design_size]=xstrdup("designsize");
+mp->int_name[mp_pausing]=xstrdup("pausing");
+mp->int_name[mp_showstopping]=xstrdup("showstopping");
+mp->int_name[mp_fontmaking]=xstrdup("fontmaking");
+mp->int_name[mp_linejoin]=xstrdup("linejoin");
+mp->int_name[mp_linecap]=xstrdup("linecap");
+mp->int_name[mp_miterlimit]=xstrdup("miterlimit");
+mp->int_name[mp_warning_check]=xstrdup("warningcheck");
+mp->int_name[mp_boundary_char]=xstrdup("boundarychar");
+mp->int_name[mp_prologues]=xstrdup("prologues");
+mp->int_name[mp_true_corners]=xstrdup("truecorners");
+mp->int_name[mp_default_color_model]=xstrdup("defaultcolormodel");
+mp->int_name[mp_procset]=xstrdup("mpprocset");
+mp->int_name[mp_gtroffmode]=xstrdup("troffmode");
+mp->int_name[mp_restore_clip_color]=xstrdup("restoreclipcolor");
+mp->int_name[mp_output_template]=xstrdup("outputtemplate");
+mp->int_name[mp_output_format]=xstrdup("outputformat");
+
+@ The following procedure, which is called just before \MP\ initializes its
+input and output, establishes the initial values of the date and time.
+@^system dependencies@>
+
+Note that the values are |scaled| integers. Hence \MP\ can no longer
+be used after the year 32767.
+
+@c
+static void mp_fix_date_and_time (MP mp) {
+ time_t aclock = time ((time_t *) 0);
+ struct tm *tmptr = localtime (&aclock);
+ mp->internal[mp_time]=
+ (tmptr->tm_hour*60+tmptr->tm_min)*unity; /* minutes since midnight */
+ mp->internal[mp_day]=(tmptr->tm_mday)*unity; /* fourth day of the month */
+ mp->internal[mp_month]=(tmptr->tm_mon+1)*unity; /* seventh month of the year */
+ mp->internal[mp_year]=(tmptr->tm_year+1900)*unity; /* Anno Domini */
+}
+
+@ @<Declarations@>=
+static void mp_fix_date_and_time (MP mp) ;
+
+@ \MP\ is occasionally supposed to print diagnostic information that
+goes only into the transcript file, unless |mp_tracing_online| is positive.
+Now that we have defined |mp_tracing_online| we can define
+two routines that adjust the destination of print commands:
+
+@<Declarations@>=
+static void mp_begin_diagnostic (MP mp) ;
+static void mp_end_diagnostic (MP mp,boolean blank_line);
+static void mp_print_diagnostic (MP mp, const char *s, const char *t, boolean nuline) ;
+
+@ @<Basic printing...@>=
+void mp_begin_diagnostic (MP mp) { /* prepare to do some tracing */
+ mp->old_setting=mp->selector;
+ if ((mp->internal[mp_tracing_online]<=0)&&(mp->selector==term_and_log)){
+ decr(mp->selector);
+ if ( mp->history==mp_spotless ) mp->history=mp_warning_issued;
+ }
+}
+@#
+void mp_end_diagnostic (MP mp,boolean blank_line) {
+ /* restore proper conditions after tracing */
+ mp_print_nl(mp, "");
+ if ( blank_line ) mp_print_ln(mp);
+ mp->selector=mp->old_setting;
+}
+
+@
+
+@<Glob...@>=
+unsigned int old_setting;
+
+@ We will occasionally use |begin_diagnostic| in connection with line-number
+printing, as follows. (The parameter |s| is typically |"Path"| or
+|"Cycle spec"|, etc.)
+
+@<Basic printing...@>=
+void mp_print_diagnostic (MP mp, const char *s, const char *t, boolean nuline) {
+ mp_begin_diagnostic(mp);
+ if ( nuline ) mp_print_nl(mp, s); else mp_print(mp, s);
+ mp_print(mp, " at line ");
+ mp_print_int(mp, mp_true_line(mp));
+ mp_print(mp, t); mp_print_char(mp, xord(':'));
+}
+
+@ The 256 |ASCII_code| characters are grouped into classes by means of
+the |char_class| table. Individual class numbers have no semantic
+or syntactic significance, except in a few instances defined here.
+There's also |max_class|, which can be used as a basis for additional
+class numbers in nonstandard extensions of \MP.
+
+@d digit_class 0 /* the class number of \.{0123456789} */
+@d period_class 1 /* the class number of `\..' */
+@d space_class 2 /* the class number of spaces and nonstandard characters */
+@d percent_class 3 /* the class number of `\.\%' */
+@d string_class 4 /* the class number of `\."' */
+@d right_paren_class 8 /* the class number of `\.)' */
+@d isolated_classes 5: case 6: case 7: case 8 /* characters that make length-one tokens only */
+@d letter_class 9 /* letters and the underline character */
+@d left_bracket_class 17 /* `\.[' */
+@d right_bracket_class 18 /* `\.]' */
+@d invalid_class 20 /* bad character in the input */
+@d max_class 20 /* the largest class number */
+
+@<Glob...@>=
+int char_class[256]; /* the class numbers */
+
+@ If changes are made to accommodate non-ASCII character sets, they should
+follow the guidelines in Appendix~C of {\sl The {\logos METAFONT\/}book}.
+@:METAFONTbook}{\sl The {\logos METAFONT\/}book@>
+@^system dependencies@>
+
+@<Set initial ...@>=
+for (k='0';k<='9';k++)
+ mp->char_class[k]=digit_class;
+mp->char_class['.']=period_class;
+mp->char_class[' ']=space_class;
+mp->char_class['%']=percent_class;
+mp->char_class['"']=string_class;
+mp->char_class[',']=5;
+mp->char_class[';']=6;
+mp->char_class['(']=7;
+mp->char_class[')']=right_paren_class;
+for (k='A';k<= 'Z';k++ )
+ mp->char_class[k]=letter_class;
+for (k='a';k<='z';k++)
+ mp->char_class[k]=letter_class;
+mp->char_class['_']=letter_class;
+mp->char_class['<']=10;
+mp->char_class['=']=10;
+mp->char_class['>']=10;
+mp->char_class[':']=10;
+mp->char_class['|']=10;
+mp->char_class['`']=11;
+mp->char_class['\'']=11;
+mp->char_class['+']=12;
+mp->char_class['-']=12;
+mp->char_class['/']=13;
+mp->char_class['*']=13;
+mp->char_class['\\']=13;
+mp->char_class['!']=14;
+mp->char_class['?']=14;
+mp->char_class['#']=15;
+mp->char_class['&']=15;
+mp->char_class['@@']=15;
+mp->char_class['$']=15;
+mp->char_class['^']=16;
+mp->char_class['~']=16;
+mp->char_class['[']=left_bracket_class;
+mp->char_class[']']=right_bracket_class;
+mp->char_class['{']=19;
+mp->char_class['}']=19;
+for (k=0;k<' ';k++)
+ mp->char_class[k]=invalid_class;
+mp->char_class['\t']=space_class;
+mp->char_class['\f']=space_class;
+for (k=127;k<=255;k++)
+ mp->char_class[k]=invalid_class;
+
+@* \[13] The hash table.
+Symbolic tokens are stored and retrieved by means of a fairly standard hash
+table algorithm called the method of ``coalescing lists'' (cf.\ Algorithm 6.4C
+in {\sl The Art of Computer Programming\/}). Once a symbolic token enters the
+table, it is never removed.
+
+The actual sequence of characters forming a symbolic token is
+stored in the |str_pool| array together with all the other strings. An
+auxiliary array |hash| consists of items with two halfword fields per
+word. The first of these, called |mp_next(p)|, points to the next identifier
+belonging to the same coalesced list as the identifier corresponding to~|p|;
+and the other, called |text(p)|, points to the |str_start| entry for
+|p|'s identifier. If position~|p| of the hash table is empty, we have
+|text(p)=0|; if position |p| is either empty or the end of a coalesced
+hash list, we have |mp_next(p)=0|.
+
+An auxiliary pointer variable called |hash_used| is maintained in such a
+way that all locations |p>=hash_used| are nonempty. The global variable
+|st_count| tells how many symbolic tokens have been defined, if statistics
+are being kept.
+
+The first 256 locations of |hash| are reserved for symbols of length one.
+
+There's a parallel array called |eqtb| that contains the current equivalent
+values of each symbolic token. The entries of this array consist of
+two halfwords called |eq_type| (a command code) and |equiv| (a secondary
+piece of information that qualifies the |eq_type|).
+
+@d eq_type(A) mp->eqtb[(A)].lh /* the current ``meaning'' of a symbolic token */
+@d equiv(A) mp->eqtb[(A)].rh /* parametric part of a token's meaning */
+@d hash_is_full (mp->hash_used==hash_base) /* are all positions occupied? */
+
+@(mpmp.h@>=
+#define mp_next(A) mp->hash[(A)].lh /* link for coalesced lists */
+#define text(A) mp->hash[(A)].rh /* string number for symbolic token name */
+#define hash_base 257 /* hashing actually starts here */
+
+@ @<Glob...@>=
+pointer hash_used; /* allocation pointer for |hash| */
+integer st_count; /* total number of known identifiers */
+
+@ Certain entries in the hash table are ``frozen'' and not redefinable,
+since they are used in error recovery.
+
+@(mpmp.h@>=
+#define hash_top (integer)(hash_base+mp->hash_size) /* the first location of the frozen area */
+#define frozen_inaccessible hash_top /* |hash| location to protect the frozen area */
+#define frozen_repeat_loop (hash_top+1) /* |hash| location of a loop-repeat token */
+#define frozen_right_delimiter (hash_top+2) /* |hash| location of a permanent `\.)' */
+#define frozen_left_bracket (hash_top+3) /* |hash| location of a permanent `\.[' */
+#define frozen_slash (hash_top+4) /* |hash| location of a permanent `\./' */
+#define frozen_colon (hash_top+5) /* |hash| location of a permanent `\.:' */
+#define frozen_semicolon (hash_top+6) /* |hash| location of a permanent `\.;' */
+#define frozen_end_for (hash_top+7) /* |hash| location of a permanent \&{endfor} */
+#define frozen_end_def (hash_top+8) /* |hash| location of a permanent \&{enddef} */
+#define frozen_fi (hash_top+9) /* |hash| location of a permanent \&{fi} */
+#define frozen_end_group (hash_top+10) /* |hash| location of a permanent `\.{endgroup}' */
+#define frozen_etex (hash_top+11) /* |hash| location of a permanent \&{etex} */
+#define frozen_mpx_break (hash_top+12) /* |hash| location of a permanent \&{mpxbreak} */
+#define frozen_bad_vardef (hash_top+13) /* |hash| location of `\.{a bad variable}' */
+#define frozen_undefined (hash_top+14) /* |hash| location that never gets defined */
+#define hash_end (integer)(hash_top+14) /* the actual size of the |hash| and |eqtb| arrays */
+
+
+@ @<Glob...@>=
+two_halves *hash; /* the hash table */
+two_halves *eqtb; /* the equivalents */
+
+@ @<Allocate or initialize ...@>=
+mp->hash = xmalloc((hash_end+1),sizeof(two_halves));
+mp->eqtb = xmalloc((hash_end+1),sizeof(two_halves));
+
+@ @<Dealloc variables@>=
+xfree(mp->hash);
+xfree(mp->eqtb);
+
+@ @<Set init...@>=
+mp_next(1)=0; text(1)=0; eq_type(1)=tag_token; equiv(1)=null;
+for (k=2;k<=hash_end;k++) {
+ mp->hash[k]=mp->hash[1]; mp->eqtb[k]=mp->eqtb[1];
+}
+
+@ @<Initialize table entries...@>=
+mp->hash_used=frozen_inaccessible; /* nothing is used */
+mp->st_count=0;
+text(frozen_bad_vardef)=intern("a bad variable");
+text(frozen_etex)=intern("etex");
+text(frozen_mpx_break)=intern("mpxbreak");
+text(frozen_fi)=intern("fi");
+text(frozen_end_group)=intern("endgroup");
+text(frozen_end_def)=intern("enddef");
+text(frozen_end_for)=intern("endfor");
+text(frozen_semicolon)=intern(";");
+text(frozen_colon)=intern(":");
+text(frozen_slash)=intern("/");
+text(frozen_left_bracket)=intern("[");
+text(frozen_right_delimiter)=intern(")");
+text(frozen_inaccessible)=intern(" INACCESSIBLE");
+eq_type(frozen_right_delimiter)=right_delimiter;
+
+@ @<Check the ``constant'' values...@>=
+if ( hash_end+mp->max_internal>max_halfword ) mp->bad=17;
+
+@ Here is the subroutine that searches the hash table for an identifier
+that matches a given string of length~|l| appearing in |buffer[j..
+(j+l-1)]|. If the identifier is not found, it is inserted; hence it
+will always be found, and the corresponding hash table address
+will be returned.
+
+@c
+static pointer mp_id_lookup (MP mp,integer j, integer l) { /* search the hash table */
+ integer h; /* hash code */
+ pointer p; /* index in |hash| array */
+ pointer k; /* index in |buffer| array */
+ if (l==1) {
+ @<Treat special case of length 1 and |break|@>;
+ }
+ @<Compute the hash code |h|@>;
+ p=h+hash_base; /* we start searching here; note that |0<=h<hash_prime| */
+ while (true) {
+ if (text(p)>0 && length(text(p))==l && mp_str_eq_buf(mp, text(p),j))
+ break;
+ if ( mp_next(p)==0 ) {
+ @<Insert a new symbolic token after |p|, then
+ make |p| point to it and |break|@>;
+ }
+ p=mp_next(p);
+ }
+ return p;
+}
+
+@ @<Treat special case of length 1...@>=
+ p=mp->buffer[j]+1; text(p)=p-1; return p;
+
+
+@ @<Insert a new symbolic...@>=
+{
+if ( text(p)>0 ) {
+ do {
+ if ( hash_is_full )
+ mp_overflow(mp, "hash size",(integer)mp->hash_size);
+@:MetaPost capacity exceeded hash size}{\quad hash size@>
+ decr(mp->hash_used);
+ } while (text(mp->hash_used)!=0); /* search for an empty location in |hash| */
+ mp_next(p)=mp->hash_used;
+ p=mp->hash_used;
+}
+str_room(l);
+for (k=j;k<j+l;k++) {
+ append_char(mp->buffer[k]);
+}
+text(p)=mp_make_string(mp);
+mp->str_ref[text(p)]=max_str_ref;
+incr(mp->st_count);
+break;
+}
+
+
+@ The value of |hash_prime| should be roughly 85\pct! of |hash_size|, and it
+should be a prime number. The theory of hashing tells us to expect fewer
+than two table probes, on the average, when the search is successful.
+[See J.~S. Vitter, {\sl Journal of the ACM\/ \bf30} (1983), 231--258.]
+@^Vitter, Jeffrey Scott@>
+
+@<Compute the hash code |h|@>=
+h=mp->buffer[j];
+for (k=j+1;k<j+l;k++){
+ h=h+h+mp->buffer[k];
+ while ( h>=mp->hash_prime ) h=h-mp->hash_prime;
+}
+
+@ @<Search |eqtb| for equivalents equal to |p|@>=
+for (q=1;q<=hash_end;q++) {
+ if ( equiv(q)==p ) {
+ mp_print_nl(mp, "EQUIV(");
+ mp_print_int(mp, q);
+ mp_print_char(mp, xord(')'));
+ }
+}
+
+@ We need to put \MP's ``primitive'' symbolic tokens into the hash
+table, together with their command code (which will be the |eq_type|)
+and an operand (which will be the |equiv|). The |primitive| procedure
+does this, in a way that no \MP\ user can. The global value |cur_sym|
+contains the new |eqtb| pointer after |primitive| has acted.
+
+@c
+static void mp_primitive (MP mp, const char *ss, halfword c, halfword o) {
+ pool_pointer k; /* index into |str_pool| */
+ quarterword j; /* index into |buffer| */
+ quarterword l; /* length of the string */
+ str_number s;
+ s = intern(ss);
+ k=mp->str_start[s]; l=str_stop(s)-k;
+ /* we will move |s| into the (empty) |buffer| */
+ for (j=0;j<=l-1;j++) {
+ mp->buffer[j]=mp->str_pool[k+j];
+ }
+ mp->cur_sym=mp_id_lookup(mp, 0,l);
+ if ( s>=256 ) { /* we don't want to have the string twice */
+ mp_flush_string(mp, text(mp->cur_sym)); text(mp->cur_sym)=s;
+ };
+ eq_type(mp->cur_sym)=c;
+ equiv(mp->cur_sym)=o;
+}
+
+
+@ Many of \MP's primitives need no |equiv|, since they are identifiable
+by their |eq_type| alone. These primitives are loaded into the hash table
+as follows:
+
+@<Put each of \MP's primitives into the hash table@>=
+mp_primitive(mp, "..",path_join,0);
+@:.._}{\.{..} primitive@>
+mp_primitive(mp, "[",left_bracket,0); mp->eqtb[frozen_left_bracket]=mp->eqtb[mp->cur_sym];
+@:[ }{\.{[} primitive@>
+mp_primitive(mp, "]",right_bracket,0);
+@:] }{\.{]} primitive@>
+mp_primitive(mp, "}",right_brace,0);
+@:]]}{\.{\char`\}} primitive@>
+mp_primitive(mp, "{",left_brace,0);
+@:][}{\.{\char`\{} primitive@>
+mp_primitive(mp, ":",colon,0); mp->eqtb[frozen_colon]=mp->eqtb[mp->cur_sym];
+@:: }{\.{:} primitive@>
+mp_primitive(mp, "::",double_colon,0);
+@::: }{\.{::} primitive@>
+mp_primitive(mp, "||:",bchar_label,0);
+@:::: }{\.{\char'174\char'174:} primitive@>
+mp_primitive(mp, ":=",assignment,0);
+@::=_}{\.{:=} primitive@>
+mp_primitive(mp, ",",comma,0);
+@:, }{\., primitive@>
+mp_primitive(mp, ";",semicolon,0); mp->eqtb[frozen_semicolon]=mp->eqtb[mp->cur_sym];
+@:; }{\.; primitive@>
+mp_primitive(mp, "\\",relax,0);
+@:]]\\}{\.{\char`\\} primitive@>
+@#
+mp_primitive(mp, "addto",add_to_command,0);
+@:add_to_}{\&{addto} primitive@>
+mp_primitive(mp, "atleast",at_least,0);
+@:at_least_}{\&{atleast} primitive@>
+mp_primitive(mp, "begingroup",begin_group,0); mp->bg_loc=mp->cur_sym;
+@:begin_group_}{\&{begingroup} primitive@>
+mp_primitive(mp, "controls",controls,0);
+@:controls_}{\&{controls} primitive@>
+mp_primitive(mp, "curl",curl_command,0);
+@:curl_}{\&{curl} primitive@>
+mp_primitive(mp, "delimiters",delimiters,0);
+@:delimiters_}{\&{delimiters} primitive@>
+mp_primitive(mp, "endgroup",end_group,0);
+ mp->eqtb[frozen_end_group]=mp->eqtb[mp->cur_sym]; mp->eg_loc=mp->cur_sym;
+@:endgroup_}{\&{endgroup} primitive@>
+mp_primitive(mp, "everyjob",every_job_command,0);
+@:every_job_}{\&{everyjob} primitive@>
+mp_primitive(mp, "exitif",exit_test,0);
+@:exit_if_}{\&{exitif} primitive@>
+mp_primitive(mp, "expandafter",expand_after,0);
+@:expand_after_}{\&{expandafter} primitive@>
+mp_primitive(mp, "interim",interim_command,0);
+@:interim_}{\&{interim} primitive@>
+mp_primitive(mp, "let",let_command,0);
+@:let_}{\&{let} primitive@>
+mp_primitive(mp, "newinternal",new_internal,0);
+@:new_internal_}{\&{newinternal} primitive@>
+mp_primitive(mp, "of",of_token,0);
+@:of_}{\&{of} primitive@>
+mp_primitive(mp, "randomseed",mp_random_seed,0);
+@:mp_random_seed_}{\&{randomseed} primitive@>
+mp_primitive(mp, "save",save_command,0);
+@:save_}{\&{save} primitive@>
+mp_primitive(mp, "scantokens",scan_tokens,0);
+@:scan_tokens_}{\&{scantokens} primitive@>
+mp_primitive(mp, "shipout",ship_out_command,0);
+@:ship_out_}{\&{shipout} primitive@>
+mp_primitive(mp, "skipto",skip_to,0);
+@:skip_to_}{\&{skipto} primitive@>
+mp_primitive(mp, "special",special_command,0);
+@:special}{\&{special} primitive@>
+mp_primitive(mp, "fontmapfile",special_command,1);
+@:fontmapfile}{\&{fontmapfile} primitive@>
+mp_primitive(mp, "fontmapline",special_command,2);
+@:fontmapline}{\&{fontmapline} primitive@>
+mp_primitive(mp, "step",step_token,0);
+@:step_}{\&{step} primitive@>
+mp_primitive(mp, "str",str_op,0);
+@:str_}{\&{str} primitive@>
+mp_primitive(mp, "tension",tension,0);
+@:tension_}{\&{tension} primitive@>
+mp_primitive(mp, "to",to_token,0);
+@:to_}{\&{to} primitive@>
+mp_primitive(mp, "until",until_token,0);
+@:until_}{\&{until} primitive@>
+mp_primitive(mp, "within",within_token,0);
+@:within_}{\&{within} primitive@>
+mp_primitive(mp, "write",write_command,0);
+@:write_}{\&{write} primitive@>
+
+@ Each primitive has a corresponding inverse, so that it is possible to
+display the cryptic numeric contents of |eqtb| in symbolic form.
+Every call of |primitive| in this program is therefore accompanied by some
+straightforward code that forms part of the |print_cmd_mod| routine
+explained below.
+
+@<Cases of |print_cmd_mod| for symbolic printing of primitives@>=
+case add_to_command:mp_print(mp, "addto"); break;
+case assignment:mp_print(mp, ":="); break;
+case at_least:mp_print(mp, "atleast"); break;
+case bchar_label:mp_print(mp, "||:"); break;
+case begin_group:mp_print(mp, "begingroup"); break;
+case colon:mp_print(mp, ":"); break;
+case comma:mp_print(mp, ","); break;
+case controls:mp_print(mp, "controls"); break;
+case curl_command:mp_print(mp, "curl"); break;
+case delimiters:mp_print(mp, "delimiters"); break;
+case double_colon:mp_print(mp, "::"); break;
+case end_group:mp_print(mp, "endgroup"); break;
+case every_job_command:mp_print(mp, "everyjob"); break;
+case exit_test:mp_print(mp, "exitif"); break;
+case expand_after:mp_print(mp, "expandafter"); break;
+case interim_command:mp_print(mp, "interim"); break;
+case left_brace:mp_print(mp, "{"); break;
+case left_bracket:mp_print(mp, "["); break;
+case let_command:mp_print(mp, "let"); break;
+case new_internal:mp_print(mp, "newinternal"); break;
+case of_token:mp_print(mp, "of"); break;
+case path_join:mp_print(mp, ".."); break;
+case mp_random_seed:mp_print(mp, "randomseed"); break;
+case relax:mp_print_char(mp, xord('\\')); break;
+case right_brace:mp_print_char(mp, xord('}')); break;
+case right_bracket:mp_print_char(mp, xord(']')); break;
+case save_command:mp_print(mp, "save"); break;
+case scan_tokens:mp_print(mp, "scantokens"); break;
+case semicolon:mp_print_char(mp, xord(';')); break;
+case ship_out_command:mp_print(mp, "shipout"); break;
+case skip_to:mp_print(mp, "skipto"); break;
+case special_command: if ( m==2 ) mp_print(mp, "fontmapline"); else
+ if ( m==1 ) mp_print(mp, "fontmapfile"); else
+ mp_print(mp, "special"); break;
+case step_token:mp_print(mp, "step"); break;
+case str_op:mp_print(mp, "str"); break;
+case tension:mp_print(mp, "tension"); break;
+case to_token:mp_print(mp, "to"); break;
+case until_token:mp_print(mp, "until"); break;
+case within_token:mp_print(mp, "within"); break;
+case write_command:mp_print(mp, "write"); break;
+
+@ We will deal with the other primitives later, at some point in the program
+where their |eq_type| and |equiv| values are more meaningful. For example,
+the primitives for macro definitions will be loaded when we consider the
+routines that define macros.
+It is easy to find where each particular
+primitive was treated by looking in the index at the end; for example, the
+section where |"def"| entered |eqtb| is listed under `\&{def} primitive'.
+
+@* \[14] Token lists.
+A \MP\ token is either symbolic or numeric or a string, or it denotes
+a macro parameter or capsule; so there are five corresponding ways to encode it
+@^token@>
+internally: (1)~A symbolic token whose hash code is~|p|
+is represented by the number |p|, in the |info| field of a single-word
+node in~|mem|. (2)~A numeric token whose |scaled| value is~|v| is
+represented in a two-word node of~|mem|; the |type| field is |known|,
+the |name_type| field is |token|, and the |value| field holds~|v|.
+The fact that this token appears in a two-word node rather than a
+one-word node is, of course, clear from the node address.
+(3)~A string token is also represented in a two-word node; the |type|
+field is |mp_string_type|, the |name_type| field is |token|, and the
+|value| field holds the corresponding |str_number|. (4)~Capsules have
+|name_type=capsule|, and their |type| and |value| fields represent
+arbitrary values (in ways to be explained later). (5)~Macro parameters
+are like symbolic tokens in that they appear in |info| fields of
+one-word nodes. The $k$th parameter is represented by |expr_base+k| if it
+is of type \&{expr}, or by |suffix_base+k| if it is of type \&{suffix}, or
+by |text_base+k| if it is of type \&{text}. (Here |0<=k<param_size|.)
+Actual values of these parameters are kept in a separate stack, as we will
+see later. The constants |expr_base|, |suffix_base|, and |text_base| are,
+of course, chosen so that there will be no confusion between symbolic
+tokens and parameters of various types.
+
+Note that
+the `\\{type}' field of a node has nothing to do with ``type'' in a
+printer's sense. It's curious that the same word is used in such different ways.
+
+@d mp_type(A) mp->mem[(A)].hh.b0 /* identifies what kind of value this is */
+@d mp_name_type(A) mp->mem[(A)].hh.b1 /* a clue to the name of this value */
+@d token_node_size 2 /* the number of words in a large token node */
+@d value_loc(A) ((A)+1) /* the word that contains the |value| field */
+@d value(A) mp->mem[value_loc((A))].cint /* the value stored in a large token node */
+@d expr_base (hash_end+1) /* code for the zeroth \&{expr} parameter */
+@d suffix_base (expr_base+mp->param_size) /* code for the zeroth \&{suffix} parameter */
+@d text_base (suffix_base+mp->param_size) /* code for the zeroth \&{text} parameter */
+
+@<Check the ``constant''...@>=
+if ( text_base+mp->param_size>max_halfword ) mp->bad=18;
+
+@ We have set aside a two word node beginning at |null| so that we can have
+|value(null)=0|. We will make use of this coincidence later.
+
+@<Initialize table entries...@>=
+mp_link(null)=null; value(null)=0;
+
+@ A numeric token is created by the following trivial routine.
+
+@c
+static pointer mp_new_num_tok (MP mp,scaled v) {
+ pointer p; /* the new node */
+ p=mp_get_node(mp, token_node_size); value(p)=v;
+ mp_type(p)=mp_known; mp_name_type(p)=mp_token;
+ return p;
+}
+
+@ A token list is a singly linked list of nodes in |mem|, where
+each node contains a token and a link. Here's a subroutine that gets rid
+of a token list when it is no longer needed.
+
+@c static void mp_flush_token_list (MP mp,pointer p) {
+ pointer q; /* the node being recycled */
+ while ( p!=null ) {
+ q=p; p=mp_link(p);
+ if ( q>=mp->hi_mem_min ) {
+ free_avail(q);
+ } else {
+ switch (mp_type(q)) {
+ case mp_vacuous: case mp_boolean_type: case mp_known:
+ break;
+ case mp_string_type:
+ delete_str_ref(value(q));
+ break;
+ case unknown_types: case mp_pen_type: case mp_path_type:
+ case mp_picture_type: case mp_pair_type: case mp_color_type:
+ case mp_cmykcolor_type: case mp_transform_type: case mp_dependent:
+ case mp_proto_dependent: case mp_independent:
+ mp_recycle_value(mp,q);
+ break;
+ default: mp_confusion(mp, "token");
+@:this can't happen token}{\quad token@>
+ }
+ mp_free_node(mp, q,token_node_size);
+ }
+ }
+}
+
+@ The procedure |show_token_list|, which prints a symbolic form of
+the token list that starts at a given node |p|, illustrates these
+conventions. The token list being displayed should not begin with a reference
+count. However, the procedure is intended to be fairly robust, so that if the
+memory links are awry or if |p| is not really a pointer to a token list,
+almost nothing catastrophic can happen.
+
+An additional parameter |q| is also given; this parameter is either null
+or it points to a node in the token list where a certain magic computation
+takes place that will be explained later. (Basically, |q| is non-null when
+we are printing the two-line context information at the time of an error
+message; |q| marks the place corresponding to where the second line
+should begin.)
+
+The generation will stop, and `\.{\char`\ ETC.}' will be printed, if the length
+of printing exceeds a given limit~|l|; the length of printing upon entry is
+assumed to be a given amount called |null_tally|. (Note that
+|show_token_list| sometimes uses itself recursively to print
+variable names within a capsule.)
+@^recursion@>
+
+Unusual entries are printed in the form of all-caps tokens
+preceded by a space, e.g., `\.{\char`\ BAD}'.
+
+@<Declarations@>=
+static void mp_show_token_list (MP mp, integer p, integer q, integer l,
+ integer null_tally) ;
+
+@ @c
+void mp_show_token_list (MP mp, integer p, integer q, integer l,
+ integer null_tally) {
+ quarterword class,c; /* the |char_class| of previous and new tokens */
+ integer r,v; /* temporary registers */
+ class=percent_class;
+ mp->tally=null_tally;
+ while ( (p!=null) && (mp->tally<l) ) {
+ if ( p==q )
+ @<Do magic computation@>;
+ @<Display token |p| and set |c| to its class;
+ but |return| if there are problems@>;
+ class=c; p=mp_link(p);
+ }
+ if ( p!=null )
+ mp_print(mp, " ETC.");
+@.ETC@>
+ return;
+}
+
+@ @<Display token |p| and set |c| to its class...@>=
+c=letter_class; /* the default */
+if ( (p<0)||(p>mp->mem_end) ) {
+ mp_print(mp, " CLOBBERED"); return;
+@.CLOBBERED@>
+}
+if ( p<mp->hi_mem_min ) {
+ @<Display two-word token@>;
+} else {
+ r=mp_info(p);
+ if ( r>=expr_base ) {
+ @<Display a parameter token@>;
+ } else {
+ if ( r<1 ) {
+ if ( r==0 ) {
+ @<Display a collective subscript@>
+ } else {
+ mp_print(mp, " IMPOSSIBLE");
+@.IMPOSSIBLE@>
+ }
+ } else {
+ r=text(r);
+ if ( (r<0)||(r>mp->max_str_ptr) ) {
+ mp_print(mp, " NONEXISTENT");
+@.NONEXISTENT@>
+ } else {
+ @<Print string |r| as a symbolic token
+ and set |c| to its class@>;
+ }
+ }
+ }
+}
+
+@ @<Display two-word token@>=
+if ( mp_name_type(p)==mp_token ) {
+ if ( mp_type(p)==mp_known ) {
+ @<Display a numeric token@>;
+ } else if ( mp_type(p)!=mp_string_type ) {
+ mp_print(mp, " BAD");
+@.BAD@>
+ } else {
+ mp_print_char(mp, xord('"')); mp_print_str(mp, value(p)); mp_print_char(mp, xord('"'));
+ c=string_class;
+ }
+} else if ((mp_name_type(p)!=mp_capsule)||(mp_type(p)<mp_vacuous)||(mp_type(p)>mp_independent) ) {
+ mp_print(mp, " BAD");
+} else {
+ mp_print_capsule(mp,p); c=right_paren_class;
+}
+
+@ @<Display a numeric token@>=
+if ( class==digit_class )
+ mp_print_char(mp, xord(' '));
+v=value(p);
+if ( v<0 ){
+ if ( class==left_bracket_class )
+ mp_print_char(mp, xord(' '));
+ mp_print_char(mp, xord('[')); mp_print_scaled(mp, v); mp_print_char(mp, xord(']'));
+ c=right_bracket_class;
+} else {
+ mp_print_scaled(mp, v); c=digit_class;
+}
+
+
+@ Strictly speaking, a genuine token will never have |mp_info(p)=0|.
+But we will see later (in the |print_variable_name| routine) that
+it is convenient to let |mp_info(p)=0| stand for `\.{[]}'.
+
+@<Display a collective subscript@>=
+{
+if ( class==left_bracket_class )
+ mp_print_char(mp, xord(' '));
+mp_print(mp, "[]"); c=right_bracket_class;
+}
+
+@ @<Display a parameter token@>=
+{
+if ( r<suffix_base ) {
+ mp_print(mp, "(EXPR"); r=r-(expr_base);
+@.EXPR@>
+} else if ( r<text_base ) {
+ mp_print(mp, "(SUFFIX"); r=r-(suffix_base);
+@.SUFFIX@>
+} else {
+ mp_print(mp, "(TEXT"); r=r-(text_base);
+@.TEXT@>
+}
+mp_print_int(mp, r); mp_print_char(mp, xord(')')); c=right_paren_class;
+}
+
+
+@ @<Print string |r| as a symbolic token...@>=
+{
+c=mp->char_class[mp->str_pool[mp->str_start[r]]];
+if ( c==class ) {
+ switch (c) {
+ case letter_class:mp_print_char(mp, xord('.')); break;
+ case isolated_classes: break;
+ default: mp_print_char(mp, xord(' ')); break;
+ }
+}
+mp_print_str(mp, r);
+}
+
+@ @<Declarations@>=
+static void mp_print_capsule (MP mp, pointer p);
+
+@ @<Declare miscellaneous procedures that were declared |forward|@>=
+void mp_print_capsule (MP mp, pointer p) {
+ mp_print_char(mp, xord('(')); mp_print_exp(mp,p,0); mp_print_char(mp, xord(')'));
+}
+
+@ Macro definitions are kept in \MP's memory in the form of token lists
+that have a few extra one-word nodes at the beginning.
+
+The first node contains a reference count that is used to tell when the
+list is no longer needed. To emphasize the fact that a reference count is
+present, we shall refer to the |info| field of this special node as the
+|ref_count| field.
+@^reference counts@>
+
+The next node or nodes after the reference count serve to describe the
+formal parameters. They consist of zero or more parameter tokens followed
+by a code for the type of macro.
+
+@d ref_count mp_info
+ /* reference count preceding a macro definition or picture header */
+@d add_mac_ref(A) incr(ref_count((A))) /* make a new reference to a macro list */
+@d general_macro 0 /* preface to a macro defined with a parameter list */
+@d primary_macro 1 /* preface to a macro with a \&{primary} parameter */
+@d secondary_macro 2 /* preface to a macro with a \&{secondary} parameter */
+@d tertiary_macro 3 /* preface to a macro with a \&{tertiary} parameter */
+@d expr_macro 4 /* preface to a macro with an undelimited \&{expr} parameter */
+@d of_macro 5 /* preface to a macro with
+ undelimited `\&{expr} |x| \&{of}~|y|' parameters */
+@d suffix_macro 6 /* preface to a macro with an undelimited \&{suffix} parameter */
+@d text_macro 7 /* preface to a macro with an undelimited \&{text} parameter */
+
+@c
+static void mp_delete_mac_ref (MP mp,pointer p) {
+ /* |p| points to the reference count of a macro list that is
+ losing one reference */
+ if ( ref_count(p)==null ) mp_flush_token_list(mp, p);
+ else decr(ref_count(p));
+}
+
+@ The following subroutine displays a macro, given a pointer to its
+reference count.
+
+@c
+static void mp_show_macro (MP mp, pointer p, integer q, integer l) {
+ pointer r; /* temporary storage */
+ p=mp_link(p); /* bypass the reference count */
+ while ( mp_info(p)>text_macro ){
+ r=mp_link(p); mp_link(p)=null;
+ mp_show_token_list(mp, p,null,l,0); mp_link(p)=r; p=r;
+ if ( l>0 ) l=l-mp->tally; else return;
+ } /* control printing of `\.{ETC.}' */
+@.ETC@>
+ mp->tally=0;
+ switch(mp_info(p)) {
+ case general_macro:mp_print(mp, "->"); break;
+@.->@>
+ case primary_macro: case secondary_macro: case tertiary_macro:
+ mp_print_char(mp, xord('<'));
+ mp_print_cmd_mod(mp, param_type,mp_info(p));
+ mp_print(mp, ">->");
+ break;
+ case expr_macro:mp_print(mp, "<expr>->"); break;
+ case of_macro:mp_print(mp, "<expr>of<primary>->"); break;
+ case suffix_macro:mp_print(mp, "<suffix>->"); break;
+ case text_macro:mp_print(mp, "<text>->"); break;
+ } /* there are no other cases */
+ mp_show_token_list(mp, mp_link(p),q,l-mp->tally,0);
+}
+
+@* \[15] Data structures for variables.
+The variables of \MP\ programs can be simple, like `\.x', or they can
+combine the structural properties of arrays and records, like `\.{x20a.b}'.
+A \MP\ user assigns a type to a variable like \.{x20a.b} by saying, for
+example, `\.{boolean} \.{x[]a.b}'. It's time for us to study how such
+things are represented inside of the computer.
+
+Each variable value occupies two consecutive words, either in a two-word
+node called a value node, or as a two-word subfield of a larger node. One
+of those two words is called the |value| field; it is an integer,
+containing either a |scaled| numeric value or the representation of some
+other type of quantity. (It might also be subdivided into halfwords, in
+which case it is referred to by other names instead of |value|.) The other
+word is broken into subfields called |type|, |name_type|, and |link|. The
+|type| field is a quarterword that specifies the variable's type, and
+|name_type| is a quarterword from which \MP\ can reconstruct the
+variable's name (sometimes by using the |link| field as well). Thus, only
+1.25 words are actually devoted to the value itself; the other
+three-quarters of a word are overhead, but they aren't wasted because they
+allow \MP\ to deal with sparse arrays and to provide meaningful diagnostics.
+
+In this section we shall be concerned only with the structural aspects of
+variables, not their values. Later parts of the program will change the
+|type| and |value| fields, but we shall treat those fields as black boxes
+whose contents should not be touched.
+
+However, if the |type| field is |mp_structured|, there is no |value| field,
+and the second word is broken into two pointer fields called |attr_head|
+and |subscr_head|. Those fields point to additional nodes that
+contain structural information, as we shall see.
+
+@d subscr_head_loc(A) (A)+1 /* where |value|, |subscr_head| and |attr_head| are */
+@d attr_head(A) mp_info(subscr_head_loc((A))) /* pointer to attribute info */
+@d subscr_head(A) mp_link(subscr_head_loc((A))) /* pointer to subscript info */
+@d value_node_size 2 /* the number of words in a value node */
+
+@ An attribute node is three words long. Two of these words contain |type|
+and |value| fields as described above, and the third word contains
+additional information: There is an |attr_loc| field, which contains the
+hash address of the token that names this attribute; and there's also a
+|parent| field, which points to the value node of |mp_structured| type at the
+next higher level (i.e., at the level to which this attribute is
+subsidiary). The |name_type| in an attribute node is `|attr|'. The
+|link| field points to the next attribute with the same parent; these are
+arranged in increasing order, so that |attr_loc(mp_link(p))>attr_loc(p)|. The
+final attribute node links to the constant |end_attr|, whose |attr_loc|
+field is greater than any legal hash address. The |attr_head| in the
+parent points to a node whose |name_type| is |mp_structured_root|; this
+node represents the null attribute, i.e., the variable that is relevant
+when no attributes are attached to the parent. The |attr_head| node
+has the fields of either
+a value node, a subscript node, or an attribute node, depending on what
+the parent would be if it were not structured; but the subscript and
+attribute fields are ignored, so it effectively contains only the data of
+a value node. The |link| field in this special node points to an attribute
+node whose |attr_loc| field is zero; the latter node represents a collective
+subscript `\.{[]}' attached to the parent, and its |link| field points to
+the first non-special attribute node (or to |end_attr| if there are none).
+
+A subscript node likewise occupies three words, with |type| and |value| fields
+plus extra information; its |name_type| is |subscr|. In this case the
+third word is called the |subscript| field, which is a |scaled| integer.
+The |link| field points to the subscript node with the next larger
+subscript, if any; otherwise the |link| points to the attribute node
+for collective subscripts at this level. We have seen that the latter node
+contains an upward pointer, so that the parent can be deduced.
+
+The |name_type| in a parent-less value node is |root|, and the |link|
+is the hash address of the token that names this value.
+
+In other words, variables have a hierarchical structure that includes
+enough threads running around so that the program is able to move easily
+between siblings, parents, and children. An example should be helpful:
+(The reader is advised to draw a picture while reading the following
+description, since that will help to firm up the ideas.)
+Suppose that `\.x' and `\.{x.a}' and `\.{x[]b}' and `\.{x5}'
+and `\.{x20b}' have been mentioned in a user's program, where
+\.{x[]b} has been declared to be of \&{boolean} type. Let |h(x)|, |h(a)|,
+and |h(b)| be the hash addresses of \.x, \.a, and~\.b. Then
+|eq_type(h(x))=name| and |equiv(h(x))=p|, where |p|~is a two-word value
+node with |mp_name_type(p)=root| and |mp_link(p)=h(x)|. We have |type(p)=mp_structured|,
+|attr_head(p)=q|, and |subscr_head(p)=r|, where |q| points to a value
+node and |r| to a subscript node. (Are you still following this? Use
+a pencil to draw a diagram.) The lone variable `\.x' is represented by
+|type(q)| and |value(q)|; furthermore
+|mp_name_type(q)=mp_structured_root| and |mp_link(q)=q1|, where |q1| points
+to an attribute node representing `\.{x[]}'. Thus |mp_name_type(q1)=attr|,
+|attr_loc(q1)=collective_subscript=0|, |parent(q1)=p|,
+|type(q1)=mp_structured|, |attr_head(q1)=qq|, and |subscr_head(q1)=qq1|;
+|qq| is a three-word ``attribute-as-value'' node with |type(qq)=numeric_type|
+(assuming that \.{x5} is numeric, because |qq| represents `\.{x[]}'
+with no further attributes), |mp_name_type(qq)=structured_root|,
+|attr_loc(qq)=0|, |parent(qq)=p|, and
+|mp_link(qq)=qq1|. (Now pay attention to the next part.) Node |qq1| is
+an attribute node representing `\.{x[][]}', which has never yet
+occurred; its |type| field is |undefined|, and its |value| field is
+undefined. We have |mp_name_type(qq1)=attr|, |attr_loc(qq1)=collective_subscript|,
+|parent(qq1)=q1|, and |mp_link(qq1)=qq2|. Since |qq2| represents
+`\.{x[]b}', |type(qq2)=mp_unknown_boolean|; also |attr_loc(qq2)=h(b)|,
+|parent(qq2)=q1|, |mp_name_type(qq2)=attr|, |mp_link(qq2)=end_attr|.
+(Maybe colored lines will help untangle your picture.)
+ Node |r| is a subscript node with |type| and |value|
+representing `\.{x5}'; |mp_name_type(r)=subscr|, |subscript(r)=5.0|,
+and |mp_link(r)=r1| is another subscript node. To complete the picture,
+see if you can guess what |mp_link(r1)| is; give up? It's~|q1|.
+Furthermore |subscript(r1)=20.0|, |mp_name_type(r1)=subscr|,
+|type(r1)=mp_structured|, |attr_head(r1)=qqq|, |subscr_head(r1)=qqq1|,
+and we finish things off with three more nodes
+|qqq|, |qqq1|, and |qqq2| hung onto~|r1|. (Perhaps you should start again
+with a larger sheet of paper.) The value of variable \.{x20b}
+appears in node~|qqq2|, as you can well imagine.
+
+If the example in the previous paragraph doesn't make things crystal
+clear, a glance at some of the simpler subroutines below will reveal how
+things work out in practice.
+
+The only really unusual thing about these conventions is the use of
+collective subscript attributes. The idea is to avoid repeating a lot of
+type information when many elements of an array are identical macros
+(for which distinct values need not be stored) or when they don't have
+all of the possible attributes. Branches of the structure below collective
+subscript attributes do not carry actual values except for macro identifiers;
+branches of the structure below subscript nodes do not carry significant
+information in their collective subscript attributes.
+
+@d attr_loc_loc(A) ((A)+2) /* where the |attr_loc| and |parent| fields are */
+@d attr_loc(A) mp_info(attr_loc_loc((A))) /* hash address of this attribute */
+@d parent(A) mp_link(attr_loc_loc((A))) /* pointer to |mp_structured| variable */
+@d subscript_loc(A) ((A)+2) /* where the |subscript| field lives */
+@d subscript(A) mp->mem[subscript_loc((A))].sc /* subscript of this variable */
+@d attr_node_size 3 /* the number of words in an attribute node */
+@d subscr_node_size 3 /* the number of words in a subscript node */
+@d collective_subscript 0 /* code for the attribute `\.{[]}' */
+
+@<Initialize table...@>=
+attr_loc(end_attr)=hash_end+1; parent(end_attr)=null;
+
+@ Variables of type \&{pair} will have values that point to four-word
+nodes containing two numeric values. The first of these values has
+|name_type=mp_x_part_sector| and the second has |name_type=mp_y_part_sector|;
+the |link| in the first points back to the node whose |value| points
+to this four-word node.
+
+Variables of type \&{transform} are similar, but in this case their
+|value| points to a 12-word node containing six values, identified by
+|x_part_sector|, |y_part_sector|, |mp_xx_part_sector|, |mp_xy_part_sector|,
+|mp_yx_part_sector|, and |mp_yy_part_sector|.
+Finally, variables of type \&{color} have 3~values in 6~words
+identified by |mp_red_part_sector|, |mp_green_part_sector|, and |mp_blue_part_sector|.
+
+When an entire structured variable is saved, the |root| indication
+is temporarily replaced by |saved_root|.
+
+Some variables have no name; they just are used for temporary storage
+while expressions are being evaluated. We call them {\sl capsules}.
+
+@d x_part_loc(A) (A) /* where the \&{xpart} is found in a pair or transform node */
+@d y_part_loc(A) ((A)+2) /* where the \&{ypart} is found in a pair or transform node */
+@d xx_part_loc(A) ((A)+4) /* where the \&{xxpart} is found in a transform node */
+@d xy_part_loc(A) ((A)+6) /* where the \&{xypart} is found in a transform node */
+@d yx_part_loc(A) ((A)+8) /* where the \&{yxpart} is found in a transform node */
+@d yy_part_loc(A) ((A)+10) /* where the \&{yypart} is found in a transform node */
+@d red_part_loc(A) (A) /* where the \&{redpart} is found in a color node */
+@d green_part_loc(A) ((A)+2) /* where the \&{greenpart} is found in a color node */
+@d blue_part_loc(A) ((A)+4) /* where the \&{bluepart} is found in a color node */
+@d cyan_part_loc(A) (A) /* where the \&{cyanpart} is found in a color node */
+@d magenta_part_loc(A) ((A)+2) /* where the \&{magentapart} is found in a color node */
+@d yellow_part_loc(A) ((A)+4) /* where the \&{yellowpart} is found in a color node */
+@d black_part_loc(A) ((A)+6) /* where the \&{blackpart} is found in a color node */
+@d grey_part_loc(A) (A) /* where the \&{greypart} is found in a color node */
+@#
+@d pair_node_size 4 /* the number of words in a pair node */
+@d transform_node_size 12 /* the number of words in a transform node */
+@d color_node_size 6 /* the number of words in a color node */
+@d cmykcolor_node_size 8 /* the number of words in a color node */
+
+@<Glob...@>=
+quarterword big_node_size[mp_pair_type+1];
+quarterword sector0[mp_pair_type+1];
+quarterword sector_offset[mp_black_part_sector+1];
+
+@ The |sector0| array gives for each big node type, |name_type| values
+for its first subfield; the |sector_offset| array gives for each
+|name_type| value, the offset from the first subfield in words;
+and the |big_node_size| array gives the size in words for each type of
+big node.
+
+@<Set init...@>=
+mp->big_node_size[mp_transform_type]=transform_node_size;
+mp->big_node_size[mp_pair_type]=pair_node_size;
+mp->big_node_size[mp_color_type]=color_node_size;
+mp->big_node_size[mp_cmykcolor_type]=cmykcolor_node_size;
+mp->sector0[mp_transform_type]=mp_x_part_sector;
+mp->sector0[mp_pair_type]=mp_x_part_sector;
+mp->sector0[mp_color_type]=mp_red_part_sector;
+mp->sector0[mp_cmykcolor_type]=mp_cyan_part_sector;
+for (k=mp_x_part_sector;k<= mp_yy_part_sector;k++ ) {
+ mp->sector_offset[k]=2*(k-mp_x_part_sector);
+}
+for (k=mp_red_part_sector;k<= mp_blue_part_sector ; k++) {
+ mp->sector_offset[k]=2*(k-mp_red_part_sector);
+}
+for (k=mp_cyan_part_sector;k<= mp_black_part_sector;k++ ) {
+ mp->sector_offset[k]=2*(k-mp_cyan_part_sector);
+}
+
+@ If |type(p)=mp_pair_type| or |mp_transform_type| and if |value(p)=null|, the
+procedure call |init_big_node(p)| will allocate a pair or transform node
+for~|p|. The individual parts of such nodes are initially of type
+|mp_independent|.
+
+@c
+static void mp_init_big_node (MP mp,pointer p) {
+ pointer q; /* the new node */
+ quarterword s; /* its size */
+ s=mp->big_node_size[mp_type(p)]; q=mp_get_node(mp, s);
+ do {
+ s=s-2;
+ @<Make variable |q+s| newly independent@>;
+ mp_name_type(q+s)=halfp(s)+mp->sector0[mp_type(p)];
+ mp_link(q+s)=null;
+ } while (s!=0);
+ mp_link(q)=p; value(p)=q;
+}
+
+@ The |id_transform| function creates a capsule for the
+identity transformation.
+
+@c
+static pointer mp_id_transform (MP mp) {
+ pointer p,q,r; /* list manipulation registers */
+ p=mp_get_node(mp, value_node_size); mp_type(p)=mp_transform_type;
+ mp_name_type(p)=mp_capsule; value(p)=null; mp_init_big_node(mp, p); q=value(p);
+ r=q+transform_node_size;
+ do {
+ r=r-2;
+ mp_type(r)=mp_known; value(r)=0;
+ } while (r!=q);
+ value(xx_part_loc(q))=unity;
+ value(yy_part_loc(q))=unity;
+ return p;
+}
+
+@ Tokens are of type |tag_token| when they first appear, but they point
+to |null| until they are first used as the root of a variable.
+The following subroutine establishes the root node on such grand occasions.
+
+@c
+static void mp_new_root (MP mp,pointer x) {
+ pointer p; /* the new node */
+ p=mp_get_node(mp, value_node_size); mp_type(p)=undefined; mp_name_type(p)=mp_root;
+ mp_link(p)=x; equiv(x)=p;
+}
+
+@ These conventions for variable representation are illustrated by the
+|print_variable_name| routine, which displays the full name of a
+variable given only a pointer to its two-word value packet.
+
+@<Declarations@>=
+static void mp_print_variable_name (MP mp, pointer p);
+
+@ @c
+void mp_print_variable_name (MP mp, pointer p) {
+ pointer q; /* a token list that will name the variable's suffix */
+ pointer r; /* temporary for token list creation */
+ while ( mp_name_type(p)>=mp_x_part_sector ) {
+ @<Preface the output with a part specifier; |return| in the
+ case of a capsule@>;
+ }
+ q=null;
+ while ( mp_name_type(p)>mp_saved_root ) {
+ @<Ascend one level, pushing a token onto list |q|
+ and replacing |p| by its parent@>;
+ }
+ r=mp_get_avail(mp); mp_info(r)=mp_link(p); mp_link(r)=q;
+ if ( mp_name_type(p)==mp_saved_root ) mp_print(mp, "(SAVED)");
+@.SAVED@>
+ mp_show_token_list(mp, r,null,el_gordo,mp->tally);
+ mp_flush_token_list(mp, r);
+}
+
+@ @<Ascend one level, pushing a token onto list |q|...@>=
+{
+ if ( mp_name_type(p)==mp_subscr ) {
+ r=mp_new_num_tok(mp, subscript(p));
+ do {
+ p=mp_link(p);
+ } while (mp_name_type(p)!=mp_attr);
+ } else if ( mp_name_type(p)==mp_structured_root ) {
+ p=mp_link(p); goto FOUND;
+ } else {
+ if ( mp_name_type(p)!=mp_attr ) mp_confusion(mp, "var");
+@:this can't happen var}{\quad var@>
+ r=mp_get_avail(mp); mp_info(r)=attr_loc(p);
+ }
+ mp_link(r)=q; q=r;
+FOUND:
+ p=parent(p);
+}
+
+@ @<Preface the output with a part specifier...@>=
+{ switch (mp_name_type(p)) {
+ case mp_x_part_sector: mp_print_char(mp, xord('x')); break;
+ case mp_y_part_sector: mp_print_char(mp, xord('y')); break;
+ case mp_xx_part_sector: mp_print(mp, "xx"); break;
+ case mp_xy_part_sector: mp_print(mp, "xy"); break;
+ case mp_yx_part_sector: mp_print(mp, "yx"); break;
+ case mp_yy_part_sector: mp_print(mp, "yy"); break;
+ case mp_red_part_sector: mp_print(mp, "red"); break;
+ case mp_green_part_sector: mp_print(mp, "green"); break;
+ case mp_blue_part_sector: mp_print(mp, "blue"); break;
+ case mp_cyan_part_sector: mp_print(mp, "cyan"); break;
+ case mp_magenta_part_sector: mp_print(mp, "magenta"); break;
+ case mp_yellow_part_sector: mp_print(mp, "yellow"); break;
+ case mp_black_part_sector: mp_print(mp, "black"); break;
+ case mp_grey_part_sector: mp_print(mp, "grey"); break;
+ case mp_capsule:
+ mp_print(mp, "%CAPSULE"); mp_print_int(mp, p-null); return;
+ break;
+@.CAPSULE@>
+ } /* there are no other cases */
+ mp_print(mp, "part ");
+ p=mp_link(p-mp->sector_offset[mp_name_type(p)]);
+}
+
+@ The |interesting| function returns |true| if a given variable is not
+in a capsule, or if the user wants to trace capsules.
+
+@c
+static boolean mp_interesting (MP mp,pointer p) {
+ quarterword t; /* a |name_type| */
+ if ( mp->internal[mp_tracing_capsules]>0 ) {
+ return true;
+ } else {
+ t=mp_name_type(p);
+ if ( t>=mp_x_part_sector ) if ( t!=mp_capsule )
+ t=mp_name_type(mp_link(p-mp->sector_offset[t]));
+ return (t!=mp_capsule);
+ }
+}
+
+@ Now here is a subroutine that converts an unstructured type into an
+equivalent structured type, by inserting a |mp_structured| node that is
+capable of growing. This operation is done only when |mp_name_type(p)=root|,
+|subscr|, or |attr|.
+
+The procedure returns a pointer to the new node that has taken node~|p|'s
+place in the structure. Node~|p| itself does not move, nor are its
+|value| or |type| fields changed in any way.
+
+@c
+static pointer mp_new_structure (MP mp,pointer p) {
+ pointer q,r=0; /* list manipulation registers */
+ switch (mp_name_type(p)) {
+ case mp_root:
+ q=mp_link(p); r=mp_get_node(mp, value_node_size); equiv(q)=r;
+ break;
+ case mp_subscr:
+ @<Link a new subscript node |r| in place of node |p|@>;
+ break;
+ case mp_attr:
+ @<Link a new attribute node |r| in place of node |p|@>;
+ break;
+ default:
+ mp_confusion(mp, "struct");
+@:this can't happen struct}{\quad struct@>
+ break;
+ }
+ mp_link(r)=mp_link(p); mp_type(r)=mp_structured; mp_name_type(r)=mp_name_type(p);
+ attr_head(r)=p; mp_name_type(p)=mp_structured_root;
+ q=mp_get_node(mp, attr_node_size); mp_link(p)=q; subscr_head(r)=q;
+ parent(q)=r; mp_type(q)=undefined; mp_name_type(q)=mp_attr; mp_link(q)=end_attr;
+ attr_loc(q)=collective_subscript;
+ return r;
+}
+
+@ @<Link a new subscript node |r| in place of node |p|@>=
+{
+ q=p;
+ do {
+ q=mp_link(q);
+ } while (mp_name_type(q)!=mp_attr);
+ q=parent(q); r=subscr_head_loc(q); /* |mp_link(r)=subscr_head(q)| */
+ do {
+ q=r; r=mp_link(r);
+ } while (r!=p);
+ r=mp_get_node(mp, subscr_node_size);
+ mp_link(q)=r; subscript(r)=subscript(p);
+}
+
+@ If the attribute is |collective_subscript|, there are two pointers to
+node~|p|, so we must change both of them.
+
+@<Link a new attribute node |r| in place of node |p|@>=
+{
+ q=parent(p); r=attr_head(q);
+ do {
+ q=r; r=mp_link(r);
+ } while (r!=p);
+ r=mp_get_node(mp, attr_node_size); mp_link(q)=r;
+ mp->mem[attr_loc_loc(r)]=mp->mem[attr_loc_loc(p)]; /* copy |attr_loc| and |parent| */
+ if ( attr_loc(p)==collective_subscript ) {
+ q=subscr_head_loc(parent(p));
+ while ( mp_link(q)!=p ) q=mp_link(q);
+ mp_link(q)=r;
+ }
+}
+
+@ The |find_variable| routine is given a pointer~|t| to a nonempty token
+list of suffixes; it returns a pointer to the corresponding two-word
+value. For example, if |t| points to token \.x followed by a numeric
+token containing the value~7, |find_variable| finds where the value of
+\.{x7} is stored in memory. This may seem a simple task, and it
+usually is, except when \.{x7} has never been referenced before.
+Indeed, \.x may never have even been subscripted before; complexities
+arise with respect to updating the collective subscript information.
+
+If a macro type is detected anywhere along path~|t|, or if the first
+item on |t| isn't a |tag_token|, the value |null| is returned.
+Otherwise |p| will be a non-null pointer to a node such that
+|undefined<type(p)<mp_structured|.
+
+@d abort_find { return null; }
+
+@c
+static pointer mp_find_variable (MP mp,pointer t) {
+ pointer p,q,r,s; /* nodes in the ``value'' line */
+ pointer pp,qq,rr,ss; /* nodes in the ``collective'' line */
+ integer n; /* subscript or attribute */
+ memory_word save_word; /* temporary storage for a word of |mem| */
+@^inner loop@>
+ p=mp_info(t); t=mp_link(t);
+ if ( (eq_type(p) % outer_tag) != tag_token ) abort_find;
+ if ( equiv(p)==null ) mp_new_root(mp, p);
+ p=equiv(p); pp=p;
+ while ( t!=null ) {
+ @<Make sure that both nodes |p| and |pp| are of |mp_structured| type@>;
+ if ( t<mp->hi_mem_min ) {
+ @<Descend one level for the subscript |value(t)|@>
+ } else {
+ @<Descend one level for the attribute |mp_info(t)|@>;
+ }
+ t=mp_link(t);
+ }
+ if ( mp_type(pp)>=mp_structured ) {
+ if ( mp_type(pp)==mp_structured ) pp=attr_head(pp); else abort_find;
+ }
+ if ( mp_type(p)==mp_structured ) p=attr_head(p);
+ if ( mp_type(p)==undefined ) {
+ if ( mp_type(pp)==undefined ) { mp_type(pp)=mp_numeric_type; value(pp)=null; };
+ mp_type(p)=mp_type(pp); value(p)=null;
+ };
+ return p;
+}
+
+@ Although |pp| and |p| begin together, they diverge when a subscript occurs;
+|pp|~stays in the collective line while |p|~goes through actual subscript
+values.
+
+@<Make sure that both nodes |p| and |pp|...@>=
+if ( mp_type(pp)!=mp_structured ) {
+ if ( mp_type(pp)>mp_structured ) abort_find;
+ ss=mp_new_structure(mp, pp);
+ if ( p==pp ) p=ss;
+ pp=ss;
+}; /* now |type(pp)=mp_structured| */
+if ( mp_type(p)!=mp_structured ) /* it cannot be |>mp_structured| */
+ p=mp_new_structure(mp, p) /* now |type(p)=mp_structured| */
+
+@ We want this part of the program to be reasonably fast, in case there are
+@^inner loop@>
+lots of subscripts at the same level of the data structure. Therefore
+we store an ``infinite'' value in the word that appears at the end of the
+subscript list, even though that word isn't part of a subscript node.
+
+@<Descend one level for the subscript |value(t)|@>=
+{
+ n=value(t);
+ pp=mp_link(attr_head(pp)); /* now |attr_loc(pp)=collective_subscript| */
+ q=mp_link(attr_head(p)); save_word=mp->mem[subscript_loc(q)];
+ subscript(q)=el_gordo; s=subscr_head_loc(p); /* |mp_link(s)=subscr_head(p)| */
+ do {
+ r=s; s=mp_link(s);
+ } while (n>subscript(s));
+ if ( n==subscript(s) ) {
+ p=s;
+ } else {
+ p=mp_get_node(mp, subscr_node_size); mp_link(r)=p; mp_link(p)=s;
+ subscript(p)=n; mp_name_type(p)=mp_subscr; mp_type(p)=undefined;
+ }
+ mp->mem[subscript_loc(q)]=save_word;
+}
+
+@ @<Descend one level for the attribute |mp_info(t)|@>=
+{
+ n=mp_info(t);
+ ss=attr_head(pp);
+ do {
+ rr=ss; ss=mp_link(ss);
+ } while (n>attr_loc(ss));
+ if ( n<attr_loc(ss) ) {
+ qq=mp_get_node(mp, attr_node_size); mp_link(rr)=qq; mp_link(qq)=ss;
+ attr_loc(qq)=n; mp_name_type(qq)=mp_attr; mp_type(qq)=undefined;
+ parent(qq)=pp; ss=qq;
+ }
+ if ( p==pp ) {
+ p=ss; pp=ss;
+ } else {
+ pp=ss; s=attr_head(p);
+ do {
+ r=s; s=mp_link(s);
+ } while (n>attr_loc(s));
+ if ( n==attr_loc(s) ) {
+ p=s;
+ } else {
+ q=mp_get_node(mp, attr_node_size); mp_link(r)=q; mp_link(q)=s;
+ attr_loc(q)=n; mp_name_type(q)=mp_attr; mp_type(q)=undefined;
+ parent(q)=p; p=q;
+ }
+ }
+}
+
+@ Variables lose their former values when they appear in a type declaration,
+or when they are defined to be macros or \&{let} equal to something else.
+A subroutine will be defined later that recycles the storage associated
+with any particular |type| or |value|; our goal now is to study a higher
+level process called |flush_variable|, which selectively frees parts of a
+variable structure.
+
+This routine has some complexity because of examples such as
+`\hbox{\tt numeric x[]a[]b}'
+which recycles all variables of the form \.{x[i]a[j]b} (and no others), while
+`\hbox{\tt vardef x[]a[]=...}'
+discards all variables of the form \.{x[i]a[j]} followed by an arbitrary
+suffix, except for the collective node \.{x[]a[]} itself. The obvious way
+to handle such examples is to use recursion; so that's what we~do.
+@^recursion@>
+
+Parameter |p| points to the root information of the variable;
+parameter |t| points to a list of one-word nodes that represent
+suffixes, with |info=collective_subscript| for subscripts.
+
+@<Declarations@>=
+static void mp_flush_cur_exp (MP mp,scaled v) ;
+
+@ @c
+static void mp_flush_variable (MP mp,pointer p, pointer t, boolean discard_suffixes) {
+ pointer q,r; /* list manipulation */
+ halfword n; /* attribute to match */
+ while ( t!=null ) {
+ if ( mp_type(p)!=mp_structured ) return;
+ n=mp_info(t); t=mp_link(t);
+ if ( n==collective_subscript ) {
+ r=subscr_head_loc(p); q=mp_link(r); /* |q=subscr_head(p)| */
+ while ( mp_name_type(q)==mp_subscr ){
+ mp_flush_variable(mp, q,t,discard_suffixes);
+ if ( t==null ) {
+ if ( mp_type(q)==mp_structured ) r=q;
+ else { mp_link(r)=mp_link(q); mp_free_node(mp, q,subscr_node_size); }
+ } else {
+ r=q;
+ }
+ q=mp_link(r);
+ }
+ }
+ p=attr_head(p);
+ do {
+ r=p; p=mp_link(p);
+ } while (attr_loc(p)<n);
+ if ( attr_loc(p)!=n ) return;
+ }
+ if ( discard_suffixes ) {
+ mp_flush_below_variable(mp, p);
+ } else {
+ if ( mp_type(p)==mp_structured ) p=attr_head(p);
+ mp_recycle_value(mp, p);
+ }
+}
+
+@ The next procedure is simpler; it wipes out everything but |p| itself,
+which becomes undefined.
+
+@<Declarations@>=
+static void mp_flush_below_variable (MP mp, pointer p);
+
+@ @c
+void mp_flush_below_variable (MP mp,pointer p) {
+ pointer q,r; /* list manipulation registers */
+ if ( mp_type(p)!=mp_structured ) {
+ mp_recycle_value(mp, p); /* this sets |type(p)=undefined| */
+ } else {
+ q=subscr_head(p);
+ while ( mp_name_type(q)==mp_subscr ) {
+ mp_flush_below_variable(mp, q); r=q; q=mp_link(q);
+ mp_free_node(mp, r,subscr_node_size);
+ }
+ r=attr_head(p); q=mp_link(r); mp_recycle_value(mp, r);
+ if ( mp_name_type(p)<=mp_saved_root ) mp_free_node(mp, r,value_node_size);
+ else mp_free_node(mp, r,subscr_node_size);
+ /* we assume that |subscr_node_size=attr_node_size| */
+ do {
+ mp_flush_below_variable(mp, q); r=q; q=mp_link(q); mp_free_node(mp, r,attr_node_size);
+ } while (q!=end_attr);
+ mp_type(p)=undefined;
+ }
+}
+
+@ Just before assigning a new value to a variable, we will recycle the
+old value and make the old value undefined. The |und_type| routine
+determines what type of undefined value should be given, based on
+the current type before recycling.
+
+@c
+static quarterword mp_und_type (MP mp,pointer p) {
+ switch (mp_type(p)) {
+ case undefined: case mp_vacuous:
+ return undefined;
+ case mp_boolean_type: case mp_unknown_boolean:
+ return mp_unknown_boolean;
+ case mp_string_type: case mp_unknown_string:
+ return mp_unknown_string;
+ case mp_pen_type: case mp_unknown_pen:
+ return mp_unknown_pen;
+ case mp_path_type: case mp_unknown_path:
+ return mp_unknown_path;
+ case mp_picture_type: case mp_unknown_picture:
+ return mp_unknown_picture;
+ case mp_transform_type: case mp_color_type: case mp_cmykcolor_type:
+ case mp_pair_type: case mp_numeric_type:
+ return mp_type(p);
+ case mp_known: case mp_dependent: case mp_proto_dependent: case mp_independent:
+ return mp_numeric_type;
+ } /* there are no other cases */
+ return 0;
+}
+
+@ The |clear_symbol| routine is used when we want to redefine the equivalent
+of a symbolic token. It must remove any variable structure or macro
+definition that is currently attached to that symbol. If the |saving|
+parameter is true, a subsidiary structure is saved instead of destroyed.
+
+@c
+static void mp_clear_symbol (MP mp,pointer p, boolean saving) {
+ pointer q; /* |equiv(p)| */
+ q=equiv(p);
+ switch (eq_type(p) % outer_tag) {
+ case defined_macro:
+ case secondary_primary_macro:
+ case tertiary_secondary_macro:
+ case expression_tertiary_macro:
+ if ( ! saving ) mp_delete_mac_ref(mp, q);
+ break;
+ case tag_token:
+ if ( q!=null ) {
+ if ( saving ) {
+ mp_name_type(q)=mp_saved_root;
+ } else {
+ mp_flush_below_variable(mp, q);
+ mp_free_node(mp,q,value_node_size);
+ }
+ }
+ break;
+ default:
+ break;
+ }
+ mp->eqtb[p]=mp->eqtb[frozen_undefined];
+}
+
+@* \[16] Saving and restoring equivalents.
+The nested structure given by \&{begingroup} and \&{endgroup}
+allows |eqtb| entries to be saved and restored, so that temporary changes
+can be made without difficulty. When the user requests a current value to
+be saved, \MP\ puts that value into its ``save stack.'' An appearance of
+\&{endgroup} ultimately causes the old values to be removed from the save
+stack and put back in their former places.
+
+The save stack is a linked list containing three kinds of entries,
+distinguished by their |info| fields. If |p| points to a saved item,
+then
+
+\smallskip\hang
+|mp_info(p)=0| stands for a group boundary; each \&{begingroup} contributes
+such an item to the save stack and each \&{endgroup} cuts back the stack
+until the most recent such entry has been removed.
+
+\smallskip\hang
+|mp_info(p)=q|, where |1<=q<=hash_end|, means that |mem[p+1]| holds the former
+contents of |eqtb[q]|. Such save stack entries are generated by \&{save}
+commands.
+
+\smallskip\hang
+|mp_info(p)=hash_end+q|, where |q>0|, means that |value(p)| is a |scaled|
+integer to be restored to internal parameter number~|q|. Such entries
+are generated by \&{interim} commands.
+
+\smallskip\noindent
+The global variable |save_ptr| points to the top item on the save stack.
+
+@d save_node_size 2 /* number of words per non-boundary save-stack node */
+@d saved_equiv(A) mp->mem[(A)+1].hh /* where an |eqtb| entry gets saved */
+@d save_boundary_item(A) { (A)=mp_get_avail(mp); mp_info((A))=0;
+ mp_link((A))=mp->save_ptr; mp->save_ptr=(A);
+ }
+
+@<Glob...@>=
+pointer save_ptr; /* the most recently saved item */
+
+@ @<Set init...@>=mp->save_ptr=null;
+
+@ The |save_variable| routine is given a hash address |q|; it salts this
+address in the save stack, together with its current equivalent,
+then makes token~|q| behave as though it were brand new.
+
+Nothing is stacked when |save_ptr=null|, however; there's no way to remove
+things from the stack when the program is not inside a group, so there's
+no point in wasting the space.
+
+@c
+static void mp_save_variable (MP mp,pointer q) {
+ pointer p; /* temporary register */
+ if ( mp->save_ptr!=null ){
+ p=mp_get_node(mp, save_node_size); mp_info(p)=q; mp_link(p)=mp->save_ptr;
+ saved_equiv(p)=mp->eqtb[q]; mp->save_ptr=p;
+ }
+ mp_clear_symbol(mp, q,(mp->save_ptr!=null));
+}
+
+@ Similarly, |save_internal| is given the location |q| of an internal
+quantity like |mp_tracing_pens|. It creates a save stack entry of the
+third kind.
+
+@c
+static void mp_save_internal (MP mp,halfword q) {
+ pointer p; /* new item for the save stack */
+ if ( mp->save_ptr!=null ){
+ p=mp_get_node(mp, save_node_size); mp_info(p)=hash_end+q;
+ mp_link(p)=mp->save_ptr; value(p)=mp->internal[q]; mp->save_ptr=p;
+ }
+}
+
+@ At the end of a group, the |unsave| routine restores all of the saved
+equivalents in reverse order. This routine will be called only when there
+is at least one boundary item on the save stack.
+
+@c
+static void mp_unsave (MP mp) {
+ pointer q; /* index to saved item */
+ pointer p; /* temporary register */
+ while ( mp_info(mp->save_ptr)!=0 ) {
+ q=mp_info(mp->save_ptr);
+ if ( q>hash_end ) {
+ if ( mp->internal[mp_tracing_restores]>0 ) {
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "{restoring ");
+ mp_print(mp, mp->int_name[q-(hash_end)]); mp_print_char(mp, xord('='));
+ mp_print_scaled(mp, value(mp->save_ptr)); mp_print_char(mp, xord('}'));
+ mp_end_diagnostic(mp, false);
+ }
+ mp->internal[q-(hash_end)]=value(mp->save_ptr);
+ } else {
+ if ( mp->internal[mp_tracing_restores]>0 ) {
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "{restoring ");
+ mp_print_text(q); mp_print_char(mp, xord('}'));
+ mp_end_diagnostic(mp, false);
+ }
+ mp_clear_symbol(mp, q,false);
+ mp->eqtb[q]=saved_equiv(mp->save_ptr);
+ if ( eq_type(q) % outer_tag==tag_token ) {
+ p=equiv(q);
+ if ( p!=null ) mp_name_type(p)=mp_root;
+ }
+ }
+ p=mp_link(mp->save_ptr);
+ mp_free_node(mp, mp->save_ptr,save_node_size); mp->save_ptr=p;
+ }
+ p=mp_link(mp->save_ptr); free_avail(mp->save_ptr); mp->save_ptr=p;
+}
+
+@* \[17] Data structures for paths.
+When a \MP\ user specifies a path, \MP\ will create a list of knots
+and control points for the associated cubic spline curves. If the
+knots are $z_0$, $z_1$, \dots, $z_n$, there are control points
+$z_k^+$ and $z_{k+1}^-$ such that the cubic splines between knots
+$z_k$ and $z_{k+1}$ are defined by B\'ezier's formula
+@:Bezier}{B\'ezier, Pierre Etienne@>
+$$\eqalign{z(t)&=B(z_k,z_k^+,z_{k+1}^-,z_{k+1};t)\cr
+&=(1-t)^3z_k+3(1-t)^2tz_k^++3(1-t)t^2z_{k+1}^-+t^3z_{k+1}\cr}$$
+for |0<=t<=1|.
+
+There is a 8-word node for each knot $z_k$, containing one word of
+control information and six words for the |x| and |y| coordinates of
+$z_k^-$ and $z_k$ and~$z_k^+$. The control information appears in the
+|mp_left_type| and |mp_right_type| fields, which each occupy a quarter of
+the first word in the node; they specify properties of the curve as it
+enters and leaves the knot. There's also a halfword |link| field,
+which points to the following knot, and a final supplementary word (of
+which only a quarter is used).
+
+If the path is a closed contour, knots 0 and |n| are identical;
+i.e., the |link| in knot |n-1| points to knot~0. But if the path
+is not closed, the |mp_left_type| of knot~0 and the |mp_right_type| of knot~|n|
+are equal to |endpoint|. In the latter case the |link| in knot~|n| points
+to knot~0, and the control points $z_0^-$ and $z_n^+$ are not used.
+
+@d mp_left_type(A) mp->mem[(A)].hh.b0 /* characterizes the path entering this knot */
+@d mp_right_type(A) mp->mem[(A)].hh.b1 /* characterizes the path leaving this knot */
+@d mp_x_coord(A) mp->mem[(A)+1].sc /* the |x| coordinate of this knot */
+@d mp_y_coord(A) mp->mem[(A)+2].sc /* the |y| coordinate of this knot */
+@d mp_left_x(A) mp->mem[(A)+3].sc /* the |x| coordinate of previous control point */
+@d mp_left_y(A) mp->mem[(A)+4].sc /* the |y| coordinate of previous control point */
+@d mp_right_x(A) mp->mem[(A)+5].sc /* the |x| coordinate of next control point */
+@d mp_right_y(A) mp->mem[(A)+6].sc /* the |y| coordinate of next control point */
+@d x_loc(A) ((A)+1) /* where the |x| coordinate is stored in a knot */
+@d y_loc(A) ((A)+2) /* where the |y| coordinate is stored in a knot */
+@d knot_coord(A) mp->mem[(A)].sc /* |x| or |y| coordinate given |x_loc| or |y_loc| */
+@d left_coord(A) mp->mem[(A)+2].sc
+ /* coordinate of previous control point given |x_loc| or |y_loc| */
+@d right_coord(A) mp->mem[(A)+4].sc
+ /* coordinate of next control point given |x_loc| or |y_loc| */
+@d knot_node_size 8 /* number of words in a knot node */
+
+@(mplib.h@>=
+enum mp_knot_type {
+ mp_endpoint=0, /* |mp_left_type| at path beginning and |mp_right_type| at path end */
+ mp_explicit, /* |mp_left_type| or |mp_right_type| when control points are known */
+ mp_given, /* |mp_left_type| or |mp_right_type| when a direction is given */
+ mp_curl, /* |mp_left_type| or |mp_right_type| when a curl is desired */
+ mp_open, /* |mp_left_type| or |mp_right_type| when \MP\ should choose the direction */
+ mp_end_cycle
+};
+
+@ Before the B\'ezier control points have been calculated, the memory
+space they will ultimately occupy is taken up by information that can be
+used to compute them. There are four cases:
+
+\yskip
+\textindent{$\bullet$} If |mp_right_type=mp_open|, the curve should leave
+the knot in the same direction it entered; \MP\ will figure out a
+suitable direction.
+
+\yskip
+\textindent{$\bullet$} If |mp_right_type=mp_curl|, the curve should leave the
+knot in a direction depending on the angle at which it enters the next
+knot and on the curl parameter stored in |right_curl|.
+
+\yskip
+\textindent{$\bullet$} If |mp_right_type=mp_given|, the curve should leave the
+knot in a nonzero direction stored as an |angle| in |right_given|.
+
+\yskip
+\textindent{$\bullet$} If |mp_right_type=mp_explicit|, the B\'ezier control
+point for leaving this knot has already been computed; it is in the
+|mp_right_x| and |mp_right_y| fields.
+
+\yskip\noindent
+The rules for |mp_left_type| are similar, but they refer to the curve entering
+the knot, and to \\{left} fields instead of \\{right} fields.
+
+Non-|explicit| control points will be chosen based on ``tension'' parameters
+in the |left_tension| and |right_tension| fields. The
+`\&{atleast}' option is represented by negative tension values.
+@:at_least_}{\&{atleast} primitive@>
+
+For example, the \MP\ path specification
+$$\.{z0..z1..tension atleast 1..\{curl 2\}z2..z3\{-1,-2\}..tension
+ 3 and 4..p},$$
+where \.p is the path `\.{z4..controls z45 and z54..z5}', will be represented
+by the six knots
+\def\lodash{\hbox to 1.1em{\thinspace\hrulefill\thinspace}}
+$$\vbox{\halign{#\hfil&&\qquad#\hfil\cr
+|mp_left_type|&\\{left} info&|mp_x_coord,mp_y_coord|&|mp_right_type|&\\{right} info\cr
+\noalign{\yskip}
+|endpoint|&\lodash$,\,$\lodash&$x_0,y_0$&|curl|&$1.0,1.0$\cr
+|open|&\lodash$,1.0$&$x_1,y_1$&|open|&\lodash$,-1.0$\cr
+|curl|&$2.0,-1.0$&$x_2,y_2$&|curl|&$2.0,1.0$\cr
+|given|&$d,1.0$&$x_3,y_3$&|given|&$d,3.0$\cr
+|open|&\lodash$,4.0$&$x_4,y_4$&|explicit|&$x_{45},y_{45}$\cr
+|explicit|&$x_{54},y_{54}$&$x_5,y_5$&|endpoint|&\lodash$,\,$\lodash\cr}}$$
+Here |d| is the |angle| obtained by calling |n_arg(-unity,-two)|.
+Of course, this example is more complicated than anything a normal user
+would ever write.
+
+These types must satisfy certain restrictions because of the form of \MP's
+path syntax:
+(i)~|open| type never appears in the same node together with |endpoint|,
+|given|, or |curl|.
+(ii)~The |mp_right_type| of a node is |explicit| if and only if the
+|mp_left_type| of the following node is |explicit|.
+(iii)~|endpoint| types occur only at the ends, as mentioned above.
+
+@d left_curl mp_left_x /* curl information when entering this knot */
+@d left_given mp_left_x /* given direction when entering this knot */
+@d left_tension mp_left_y /* tension information when entering this knot */
+@d right_curl mp_right_x /* curl information when leaving this knot */
+@d right_given mp_right_x /* given direction when leaving this knot */
+@d right_tension mp_right_y /* tension information when leaving this knot */
+
+@ Knots can be user-supplied, or they can be created by program code,
+like the |split_cubic| function, or |copy_path|. The distinction is
+needed for the cleanup routine that runs after |split_cubic|, because
+it should only delete knots it has previously inserted, and never
+anything that was user-supplied. In order to be able to differentiate
+one knot from another, we will set |originator(p):=mp_metapost_user| when
+it appeared in the actual metapost program, and
+|originator(p):=mp_program_code| in all other cases.
+
+@d mp_originator(A) mp->mem[(A)+7].hh.b0 /* the creator of this knot */
+
+@<Exported types@>=
+enum mp_knot_originator {
+ mp_program_code=0, /* not created by a user */
+ mp_metapost_user /* created by a user */
+};
+
+@ Here is a routine that prints a given knot list
+in symbolic form. It illustrates the conventions discussed above,
+and checks for anomalies that might arise while \MP\ is being debugged.
+
+@<Declarations@>=
+static void mp_pr_path (MP mp,pointer h);
+
+@ @c
+void mp_pr_path (MP mp,pointer h) {
+ pointer p,q; /* for list traversal */
+ p=h;
+ do {
+ q=mp_link(p);
+ if ( (p==null)||(q==null) ) {
+ mp_print_nl(mp, "???"); return; /* this won't happen */
+@.???@>
+ }
+ @<Print information for adjacent knots |p| and |q|@>;
+ DONE1:
+ p=q;
+ if ( (p!=h)||(mp_left_type(h)!=mp_endpoint) ) {
+ @<Print two dots, followed by |given| or |curl| if present@>;
+ }
+ } while (p!=h);
+ if ( mp_left_type(h)!=mp_endpoint )
+ mp_print(mp, "cycle");
+}
+
+@ @<Print information for adjacent knots...@>=
+mp_print_two(mp, mp_x_coord(p),mp_y_coord(p));
+switch (mp_right_type(p)) {
+case mp_endpoint:
+ if ( mp_left_type(p)==mp_open ) mp_print(mp, "{open?}"); /* can't happen */
+@.open?@>
+ if ( (mp_left_type(q)!=mp_endpoint)||(q!=h) ) q=null; /* force an error */
+ goto DONE1;
+ break;
+case mp_explicit:
+ @<Print control points between |p| and |q|, then |goto done1|@>;
+ break;
+case mp_open:
+ @<Print information for a curve that begins |open|@>;
+ break;
+case mp_curl:
+case mp_given:
+ @<Print information for a curve that begins |curl| or |given|@>;
+ break;
+default:
+ mp_print(mp, "???"); /* can't happen */
+@.???@>
+ break;
+}
+if ( mp_left_type(q)<=mp_explicit ) {
+ mp_print(mp, "..control?"); /* can't happen */
+@.control?@>
+} else if ( (right_tension(p)!=unity)||(left_tension(q)!=unity) ) {
+ @<Print tension between |p| and |q|@>;
+}
+
+@ Since |n_sin_cos| produces |fraction| results, which we will print as if they
+were |scaled|, the magnitude of a |given| direction vector will be~4096.
+
+@<Print two dots...@>=
+{
+ mp_print_nl(mp, " ..");
+ if ( mp_left_type(p)==mp_given ) {
+ mp_n_sin_cos(mp, left_given(p)); mp_print_char(mp, xord('{'));
+ mp_print_scaled(mp, mp->n_cos); mp_print_char(mp, xord(','));
+ mp_print_scaled(mp, mp->n_sin); mp_print_char(mp, xord('}'));
+ } else if ( mp_left_type(p)==mp_curl ){
+ mp_print(mp, "{curl ");
+ mp_print_scaled(mp, left_curl(p)); mp_print_char(mp, xord('}'));
+ }
+}
+
+@ @<Print tension between |p| and |q|@>=
+{
+ mp_print(mp, "..tension ");
+ if ( right_tension(p)<0 ) mp_print(mp, "atleast");
+ mp_print_scaled(mp, abs(right_tension(p)));
+ if ( right_tension(p)!=left_tension(q) ){
+ mp_print(mp, " and ");
+ if ( left_tension(q)<0 ) mp_print(mp, "atleast");
+ mp_print_scaled(mp, abs(left_tension(q)));
+ }
+}
+
+@ @<Print control points between |p| and |q|, then |goto done1|@>=
+{
+ mp_print(mp, "..controls ");
+ mp_print_two(mp, mp_right_x(p),mp_right_y(p));
+ mp_print(mp, " and ");
+ if ( mp_left_type(q)!=mp_explicit ) {
+ mp_print(mp, "??"); /* can't happen */
+@.??@>
+ } else {
+ mp_print_two(mp, mp_left_x(q),mp_left_y(q));
+ }
+ goto DONE1;
+}
+
+@ @<Print information for a curve that begins |open|@>=
+if ( (mp_left_type(p)!=mp_explicit)&&(mp_left_type(p)!=mp_open) ) {
+ mp_print(mp, "{open?}"); /* can't happen */
+@.open?@>
+}
+
+@ A curl of 1 is shown explicitly, so that the user sees clearly that
+\MP's default curl is present.
+
+@<Print information for a curve that begins |curl|...@>=
+{
+ if ( mp_left_type(p)==mp_open )
+ mp_print(mp, "??"); /* can't happen */
+@.??@>
+ if ( mp_right_type(p)==mp_curl ) {
+ mp_print(mp, "{curl "); mp_print_scaled(mp, right_curl(p));
+ } else {
+ mp_n_sin_cos(mp, right_given(p)); mp_print_char(mp, xord('{'));
+ mp_print_scaled(mp, mp->n_cos); mp_print_char(mp, xord(','));
+ mp_print_scaled(mp, mp->n_sin);
+ }
+ mp_print_char(mp, xord('}'));
+}
+
+@ It is convenient to have another version of |pr_path| that prints the path
+as a diagnostic message.
+
+@<Declarations@>=
+static void mp_print_path (MP mp,pointer h, const char *s, boolean nuline) ;
+
+@ @c
+void mp_print_path (MP mp,pointer h, const char *s, boolean nuline) {
+ mp_print_diagnostic(mp, "Path", s, nuline); mp_print_ln(mp);
+@.Path at line...@>
+ mp_pr_path(mp, h);
+ mp_end_diagnostic(mp, true);
+}
+
+@ If we want to duplicate a knot node, we can say |copy_knot|:
+
+@c
+static pointer mp_copy_knot (MP mp,pointer p) {
+ pointer q; /* the copy */
+ int k; /* runs through the words of a knot node */
+ q=mp_get_node(mp, knot_node_size);
+ for (k=0;k<knot_node_size;k++) {
+ mp->mem[q+k]=mp->mem[p+k];
+ }
+ mp_originator(q)=mp_originator(p);
+ return q;
+}
+
+@ The |copy_path| routine makes a clone of a given path.
+
+@c
+static pointer mp_copy_path (MP mp, pointer p) {
+ pointer q,pp,qq; /* for list manipulation */
+ q=mp_copy_knot(mp, p);
+ qq=q; pp=mp_link(p);
+ while ( pp!=p ) {
+ mp_link(qq)=mp_copy_knot(mp, pp);
+ qq=mp_link(qq);
+ pp=mp_link(pp);
+ }
+ mp_link(qq)=q;
+ return q;
+}
+
+
+@ Just before |ship_out|, knot lists are exported for printing.
+
+The |gr_XXXX| macros are defined in |mppsout.h|.
+
+@c
+static mp_knot *mp_export_knot (MP mp,pointer p) {
+ mp_knot *q; /* the copy */
+ if (p==null)
+ return NULL;
+ q = xmalloc(1, sizeof (mp_knot));
+ memset(q,0,sizeof (mp_knot));
+ gr_left_type(q) = (unsigned short)mp_left_type(p);
+ gr_right_type(q) = (unsigned short)mp_right_type(p);
+ gr_x_coord(q) = mp_x_coord(p);
+ gr_y_coord(q) = mp_y_coord(p);
+ gr_left_x(q) = mp_left_x(p);
+ gr_left_y(q) = mp_left_y(p);
+ gr_right_x(q) = mp_right_x(p);
+ gr_right_y(q) = mp_right_y(p);
+ gr_originator(q) = (unsigned char)mp_originator(p);
+ return q;
+}
+
+@ The |export_knot_list| routine therefore also makes a clone
+of a given path.
+
+@c
+static mp_knot *mp_export_knot_list (MP mp, pointer p) {
+ mp_knot *q, *qq; /* for list manipulation */
+ pointer pp; /* for list manipulation */
+ if (p==null)
+ return NULL;
+ q=mp_export_knot(mp, p);
+ qq=q; pp=mp_link(p);
+ while ( pp!=p ) {
+ gr_next_knot(qq)=mp_export_knot(mp, pp);
+ qq=gr_next_knot(qq);
+ pp=mp_link(pp);
+ }
+ gr_next_knot(qq)=q;
+ return q;
+}
+
+
+@ Similarly, there's a way to copy the {\sl reverse\/} of a path. This procedure
+returns a pointer to the first node of the copy, if the path is a cycle,
+but to the final node of a non-cyclic copy. The global
+variable |path_tail| will point to the final node of the original path;
+this trick makes it easier to implement `\&{doublepath}'.
+
+All node types are assumed to be |endpoint| or |explicit| only.
+
+@c
+static pointer mp_htap_ypoc (MP mp,pointer p) {
+ pointer q,pp,qq,rr; /* for list manipulation */
+ q=mp_get_node(mp, knot_node_size); /* this will correspond to |p| */
+ qq=q; pp=p;
+ while (1) {
+ mp_right_type(qq)=mp_left_type(pp); mp_left_type(qq)=mp_right_type(pp);
+ mp_x_coord(qq)=mp_x_coord(pp); mp_y_coord(qq)=mp_y_coord(pp);
+ mp_right_x(qq)=mp_left_x(pp); mp_right_y(qq)=mp_left_y(pp);
+ mp_left_x(qq)=mp_right_x(pp); mp_left_y(qq)=mp_right_y(pp);
+ mp_originator(qq)=mp_originator(pp);
+ if ( mp_link(pp)==p ) {
+ mp_link(q)=qq; mp->path_tail=pp; return q;
+ }
+ rr=mp_get_node(mp, knot_node_size); mp_link(rr)=qq; qq=rr; pp=mp_link(pp);
+ }
+}
+
+@ @<Glob...@>=
+pointer path_tail; /* the node that links to the beginning of a path */
+
+@ When a cyclic list of knot nodes is no longer needed, it can be recycled by
+calling the following subroutine.
+
+@<Declarations@>=
+static void mp_toss_knot_list (MP mp,pointer p) ;
+
+@ @c
+void mp_toss_knot_list (MP mp,pointer p) {
+ pointer q; /* the node being freed */
+ pointer r; /* the next node */
+ q=p;
+ do {
+ r=mp_link(q);
+ mp_free_node(mp, q,knot_node_size); q=r;
+ } while (q!=p);
+}
+
+@* \[18] Choosing control points.
+Now we must actually delve into one of \MP's more difficult routines,
+the |make_choices| procedure that chooses angles and control points for
+the splines of a curve when the user has not specified them explicitly.
+The parameter to |make_choices| points to a list of knots and
+path information, as described above.
+
+A path decomposes into independent segments at ``breakpoint'' knots,
+which are knots whose left and right angles are both prespecified in
+some way (i.e., their |mp_left_type| and |mp_right_type| aren't both open).
+
+@c
+static void mp_make_choices (MP mp,pointer knots) {
+ pointer h; /* the first breakpoint */
+ pointer p,q; /* consecutive breakpoints being processed */
+ @<Other local variables for |make_choices|@>;
+ check_arith; /* make sure that |arith_error=false| */
+ if ( mp->internal[mp_tracing_choices]>0 )
+ mp_print_path(mp, knots,", before choices",true);
+ @<If consecutive knots are equal, join them explicitly@>;
+ @<Find the first breakpoint, |h|, on the path;
+ insert an artificial breakpoint if the path is an unbroken cycle@>;
+ p=h;
+ do {
+ @<Fill in the control points between |p| and the next breakpoint,
+ then advance |p| to that breakpoint@>;
+ } while (p!=h);
+ if ( mp->internal[mp_tracing_choices]>0 )
+ mp_print_path(mp, knots,", after choices",true);
+ if ( mp->arith_error ) {
+ @<Report an unexpected problem during the choice-making@>;
+ }
+}
+
+@ @<Report an unexpected problem during the choice...@>=
+{
+ print_err("Some number got too big");
+@.Some number got too big@>
+ help2("The path that I just computed is out of range.",
+ "So it will probably look funny. Proceed, for a laugh.");
+ mp_put_get_error(mp); mp->arith_error=false;
+}
+
+@ Two knots in a row with the same coordinates will always be joined
+by an explicit ``curve'' whose control points are identical with the
+knots.
+
+@<If consecutive knots are equal, join them explicitly@>=
+p=knots;
+do {
+ q=mp_link(p);
+ if ( mp_x_coord(p)==mp_x_coord(q) &&
+ mp_y_coord(p)==mp_y_coord(q) && mp_right_type(p)>mp_explicit ) {
+ mp_right_type(p)=mp_explicit;
+ if ( mp_left_type(p)==mp_open ) {
+ mp_left_type(p)=mp_curl; left_curl(p)=unity;
+ }
+ mp_left_type(q)=mp_explicit;
+ if ( mp_right_type(q)==mp_open ) {
+ mp_right_type(q)=mp_curl; right_curl(q)=unity;
+ }
+ mp_right_x(p)=mp_x_coord(p); mp_left_x(q)=mp_x_coord(p);
+ mp_right_y(p)=mp_y_coord(p); mp_left_y(q)=mp_y_coord(p);
+ }
+ p=q;
+} while (p!=knots)
+
+@ If there are no breakpoints, it is necessary to compute the direction
+angles around an entire cycle. In this case the |mp_left_type| of the first
+node is temporarily changed to |end_cycle|.
+
+@<Find the first breakpoint, |h|, on the path...@>=
+h=knots;
+while (1) {
+ if ( mp_left_type(h)!=mp_open ) break;
+ if ( mp_right_type(h)!=mp_open ) break;
+ h=mp_link(h);
+ if ( h==knots ) {
+ mp_left_type(h)=mp_end_cycle; break;
+ }
+}
+
+@ If |mp_right_type(p)<given| and |q=mp_link(p)|, we must have
+|mp_right_type(p)=mp_left_type(q)=mp_explicit| or |endpoint|.
+
+@<Fill in the control points between |p| and the next breakpoint...@>=
+q=mp_link(p);
+if ( mp_right_type(p)>=mp_given ) {
+ while ( (mp_left_type(q)==mp_open)&&(mp_right_type(q)==mp_open) ) q=mp_link(q);
+ @<Fill in the control information between
+ consecutive breakpoints |p| and |q|@>;
+} else if ( mp_right_type(p)==mp_endpoint ) {
+ @<Give reasonable values for the unused control points between |p| and~|q|@>;
+}
+p=q
+
+@ This step makes it possible to transform an explicitly computed path without
+checking the |mp_left_type| and |mp_right_type| fields.
+
+@<Give reasonable values for the unused control points between |p| and~|q|@>=
+{
+ mp_right_x(p)=mp_x_coord(p); mp_right_y(p)=mp_y_coord(p);
+ mp_left_x(q)=mp_x_coord(q); mp_left_y(q)=mp_y_coord(q);
+}
+
+@ Before we can go further into the way choices are made, we need to
+consider the underlying theory. The basic ideas implemented in |make_choices|
+are due to John Hobby, who introduced the notion of ``mock curvature''
+@^Hobby, John Douglas@>
+at a knot. Angles are chosen so that they preserve mock curvature when
+a knot is passed, and this has been found to produce excellent results.
+
+It is convenient to introduce some notations that simplify the necessary
+formulas. Let $d_{k,k+1}=\vert z\k-z_k\vert$ be the (nonzero) distance
+between knots |k| and |k+1|; and let
+$${z\k-z_k\over z_k-z_{k-1}}={d_{k,k+1}\over d_{k-1,k}}e^{i\psi_k}$$
+so that a polygonal line from $z_{k-1}$ to $z_k$ to $z\k$ turns left
+through an angle of~$\psi_k$. We assume that $\vert\psi_k\vert\L180^\circ$.
+The control points for the spline from $z_k$ to $z\k$ will be denoted by
+$$\eqalign{z_k^+&=z_k+
+ \textstyle{1\over3}\rho_k e^{i\theta_k}(z\k-z_k),\cr
+ z\k^-&=z\k-
+ \textstyle{1\over3}\sigma\k e^{-i\phi\k}(z\k-z_k),\cr}$$
+where $\rho_k$ and $\sigma\k$ are nonnegative ``velocity ratios'' at the
+beginning and end of the curve, while $\theta_k$ and $\phi\k$ are the
+corresponding ``offset angles.'' These angles satisfy the condition
+$$\theta_k+\phi_k+\psi_k=0,\eqno(*)$$
+whenever the curve leaves an intermediate knot~|k| in the direction that
+it enters.
+
+@ Let $\alpha_k$ and $\beta\k$ be the reciprocals of the ``tension'' of
+the curve at its beginning and ending points. This means that
+$\rho_k=\alpha_k f(\theta_k,\phi\k)$ and $\sigma\k=\beta\k f(\phi\k,\theta_k)$,
+where $f(\theta,\phi)$ is \MP's standard velocity function defined in
+the |velocity| subroutine. The cubic spline $B(z_k^{\phantom+},z_k^+,
+z\k^-,z\k^{\phantom+};t)$
+has curvature
+@^curvature@>
+$${2\sigma\k\sin(\theta_k+\phi\k)-6\sin\theta_k\over\rho_k^2d_{k,k+1}}
+\qquad{\rm and}\qquad
+{2\rho_k\sin(\theta_k+\phi\k)-6\sin\phi\k\over\sigma\k^2d_{k,k+1}}$$
+at |t=0| and |t=1|, respectively. The mock curvature is the linear
+@^mock curvature@>
+approximation to this true curvature that arises in the limit for
+small $\theta_k$ and~$\phi\k$, if second-order terms are discarded.
+The standard velocity function satisfies
+$$f(\theta,\phi)=1+O(\theta^2+\theta\phi+\phi^2);$$
+hence the mock curvatures are respectively
+$${2\beta\k(\theta_k+\phi\k)-6\theta_k\over\alpha_k^2d_{k,k+1}}
+\qquad{\rm and}\qquad
+{2\alpha_k(\theta_k+\phi\k)-6\phi\k\over\beta\k^2d_{k,k+1}}.\eqno(**)$$
+
+@ The turning angles $\psi_k$ are given, and equation $(*)$ above
+determines $\phi_k$ when $\theta_k$ is known, so the task of
+angle selection is essentially to choose appropriate values for each
+$\theta_k$. When equation~$(*)$ is used to eliminate $\phi$~variables
+from $(**)$, we obtain a system of linear equations of the form
+$$A_k\theta_{k-1}+(B_k+C_k)\theta_k+D_k\theta\k=-B_k\psi_k-D_k\psi\k,$$
+where
+$$A_k={\alpha_{k-1}\over\beta_k^2d_{k-1,k}},
+\qquad B_k={3-\alpha_{k-1}\over\beta_k^2d_{k-1,k}},
+\qquad C_k={3-\beta\k\over\alpha_k^2d_{k,k+1}},
+\qquad D_k={\beta\k\over\alpha_k^2d_{k,k+1}}.$$
+The tensions are always $3\over4$ or more, hence each $\alpha$ and~$\beta$
+will be at most $4\over3$. It follows that $B_k\G{5\over4}A_k$ and
+$C_k\G{5\over4}D_k$; hence the equations are diagonally dominant;
+hence they have a unique solution. Moreover, in most cases the tensions
+are equal to~1, so that $B_k=2A_k$ and $C_k=2D_k$. This makes the
+solution numerically stable, and there is an exponential damping
+effect: The data at knot $k\pm j$ affects the angle at knot~$k$ by
+a factor of~$O(2^{-j})$.
+
+@ However, we still must consider the angles at the starting and ending
+knots of a non-cyclic path. These angles might be given explicitly, or
+they might be specified implicitly in terms of an amount of ``curl.''
+
+Let's assume that angles need to be determined for a non-cyclic path
+starting at $z_0$ and ending at~$z_n$. Then equations of the form
+$$A_k\theta_{k-1}+(B_k+C_k)\theta_k+D_k\theta_{k+1}=R_k$$
+have been given for $0<k<n$, and it will be convenient to introduce
+equations of the same form for $k=0$ and $k=n$, where
+$$A_0=B_0=C_n=D_n=0.$$
+If $\theta_0$ is supposed to have a given value $E_0$, we simply
+define $C_0=1$, $D_0=0$, and $R_0=E_0$. Otherwise a curl
+parameter, $\gamma_0$, has been specified at~$z_0$; this means
+that the mock curvature at $z_0$ should be $\gamma_0$ times the
+mock curvature at $z_1$; i.e.,
+$${2\beta_1(\theta_0+\phi_1)-6\theta_0\over\alpha_0^2d_{01}}
+=\gamma_0{2\alpha_0(\theta_0+\phi_1)-6\phi_1\over\beta_1^2d_{01}}.$$
+This equation simplifies to
+$$(\alpha_0\chi_0+3-\beta_1)\theta_0+
+ \bigl((3-\alpha_0)\chi_0+\beta_1\bigr)\theta_1=
+ -\bigl((3-\alpha_0)\chi_0+\beta_1\bigr)\psi_1,$$
+where $\chi_0=\alpha_0^2\gamma_0/\beta_1^2$; so we can set $C_0=
+\chi_0\alpha_0+3-\beta_1$, $D_0=(3-\alpha_0)\chi_0+\beta_1$, $R_0=-D_0\psi_1$.
+It can be shown that $C_0>0$ and $C_0B_1-A_1D_0>0$ when $\gamma_0\G0$,
+hence the linear equations remain nonsingular.
+
+Similar considerations apply at the right end, when the final angle $\phi_n$
+may or may not need to be determined. It is convenient to let $\psi_n=0$,
+hence $\theta_n=-\phi_n$. We either have an explicit equation $\theta_n=E_n$,
+or we have
+$$\bigl((3-\beta_n)\chi_n+\alpha_{n-1}\bigr)\theta_{n-1}+
+(\beta_n\chi_n+3-\alpha_{n-1})\theta_n=0,\qquad
+ \chi_n={\beta_n^2\gamma_n\over\alpha_{n-1}^2}.$$
+
+When |make_choices| chooses angles, it must compute the coefficients of
+these linear equations, then solve the equations. To compute the coefficients,
+it is necessary to compute arctangents of the given turning angles~$\psi_k$.
+When the equations are solved, the chosen directions $\theta_k$ are put
+back into the form of control points by essentially computing sines and
+cosines.
+
+@ OK, we are ready to make the hard choices of |make_choices|.
+Most of the work is relegated to an auxiliary procedure
+called |solve_choices|, which has been introduced to keep
+|make_choices| from being extremely long.
+
+@<Fill in the control information between...@>=
+@<Calculate the turning angles $\psi_k$ and the distances $d_{k,k+1}$;
+ set $n$ to the length of the path@>;
+@<Remove |open| types at the breakpoints@>;
+mp_solve_choices(mp, p,q,n)
+
+@ It's convenient to precompute quantities that will be needed several
+times later. The values of |delta_x[k]| and |delta_y[k]| will be the
+coordinates of $z\k-z_k$, and the magnitude of this vector will be
+|delta[k]=@t$d_{k,k+1}$@>|. The path angle $\psi_k$ between $z_k-z_{k-1}$
+and $z\k-z_k$ will be stored in |psi[k]|.
+
+@<Glob...@>=
+int path_size; /* maximum number of knots between breakpoints of a path */
+scaled *delta_x;
+scaled *delta_y;
+scaled *delta; /* knot differences */
+angle *psi; /* turning angles */
+
+@ @<Dealloc variables@>=
+xfree(mp->delta_x);
+xfree(mp->delta_y);
+xfree(mp->delta);
+xfree(mp->psi);
+
+@ @<Other local variables for |make_choices|@>=
+ int k,n; /* current and final knot numbers */
+ pointer s,t; /* registers for list traversal */
+ scaled delx,dely; /* directions where |open| meets |explicit| */
+ fraction sine,cosine; /* trig functions of various angles */
+
+@ @<Calculate the turning angles...@>=
+{
+RESTART:
+ k=0; s=p; n=mp->path_size;
+ do {
+ t=mp_link(s);
+ mp->delta_x[k]=mp_x_coord(t)-mp_x_coord(s);
+ mp->delta_y[k]=mp_y_coord(t)-mp_y_coord(s);
+ mp->delta[k]=mp_pyth_add(mp, mp->delta_x[k],mp->delta_y[k]);
+ if ( k>0 ) {
+ sine=mp_make_fraction(mp, mp->delta_y[k-1],mp->delta[k-1]);
+ cosine=mp_make_fraction(mp, mp->delta_x[k-1],mp->delta[k-1]);
+ mp->psi[k]=mp_n_arg(mp, mp_take_fraction(mp, mp->delta_x[k],cosine)+
+ mp_take_fraction(mp, mp->delta_y[k],sine),
+ mp_take_fraction(mp, mp->delta_y[k],cosine)-
+ mp_take_fraction(mp, mp->delta_x[k],sine));
+ }
+ incr(k); s=t;
+ if ( k==mp->path_size ) {
+ mp_reallocate_paths(mp, mp->path_size+(mp->path_size/4));
+ goto RESTART; /* retry, loop size has changed */
+ }
+ if ( s==q ) n=k;
+ } while (!((k>=n)&&(mp_left_type(s)!=mp_end_cycle)));
+ if ( k==n ) mp->psi[n]=0; else mp->psi[k]=mp->psi[1];
+}
+
+@ When we get to this point of the code, |mp_right_type(p)| is either
+|given| or |curl| or |open|. If it is |open|, we must have
+|mp_left_type(p)=mp_end_cycle| or |mp_left_type(p)=mp_explicit|. In the latter
+case, the |open| type is converted to |given|; however, if the
+velocity coming into this knot is zero, the |open| type is
+converted to a |curl|, since we don't know the incoming direction.
+
+Similarly, |mp_left_type(q)| is either |given| or |curl| or |open| or
+|mp_end_cycle|. The |open| possibility is reduced either to |given| or to |curl|.
+
+@<Remove |open| types at the breakpoints@>=
+if ( mp_left_type(q)==mp_open ) {
+ delx=mp_right_x(q)-mp_x_coord(q); dely=mp_right_y(q)-mp_y_coord(q);
+ if ( (delx==0)&&(dely==0) ) {
+ mp_left_type(q)=mp_curl; left_curl(q)=unity;
+ } else {
+ mp_left_type(q)=mp_given; left_given(q)=mp_n_arg(mp, delx,dely);
+ }
+}
+if ( (mp_right_type(p)==mp_open)&&(mp_left_type(p)==mp_explicit) ) {
+ delx=mp_x_coord(p)-mp_left_x(p); dely=mp_y_coord(p)-mp_left_y(p);
+ if ( (delx==0)&&(dely==0) ) {
+ mp_right_type(p)=mp_curl; right_curl(p)=unity;
+ } else {
+ mp_right_type(p)=mp_given; right_given(p)=mp_n_arg(mp, delx,dely);
+ }
+}
+
+@ Linear equations need to be solved whenever |n>1|; and also when |n=1|
+and exactly one of the breakpoints involves a curl. The simplest case occurs
+when |n=1| and there is a curl at both breakpoints; then we simply draw
+a straight line.
+
+But before coding up the simple cases, we might as well face the general case,
+since we must deal with it sooner or later, and since the general case
+is likely to give some insight into the way simple cases can be handled best.
+
+When there is no cycle, the linear equations to be solved form a tridiagonal
+system, and we can apply the standard technique of Gaussian elimination
+to convert that system to a sequence of equations of the form
+$$\theta_0+u_0\theta_1=v_0,\quad
+\theta_1+u_1\theta_2=v_1,\quad\ldots,\quad
+\theta_{n-1}+u_{n-1}\theta_n=v_{n-1},\quad
+\theta_n=v_n.$$
+It is possible to do this diagonalization while generating the equations.
+Once $\theta_n$ is known, it is easy to determine $\theta_{n-1}$, \dots,
+$\theta_1$, $\theta_0$; thus, the equations will be solved.
+
+The procedure is slightly more complex when there is a cycle, but the
+basic idea will be nearly the same. In the cyclic case the right-hand
+sides will be $v_k+w_k\theta_0$ instead of simply $v_k$, and we will start
+the process off with $u_0=v_0=0$, $w_0=1$. The final equation will be not
+$\theta_n=v_n$ but $\theta_n+u_n\theta_1=v_n+w_n\theta_0$; an appropriate
+ending routine will take account of the fact that $\theta_n=\theta_0$ and
+eliminate the $w$'s from the system, after which the solution can be
+obtained as before.
+
+When $u_k$, $v_k$, and $w_k$ are being computed, the three pointer
+variables |r|, |s|,~|t| will point respectively to knots |k-1|, |k|,
+and~|k+1|. The $u$'s and $w$'s are scaled by $2^{28}$, i.e., they are
+of type |fraction|; the $\theta$'s and $v$'s are of type |angle|.
+
+@<Glob...@>=
+angle *theta; /* values of $\theta_k$ */
+fraction *uu; /* values of $u_k$ */
+angle *vv; /* values of $v_k$ */
+fraction *ww; /* values of $w_k$ */
+
+@ @<Dealloc variables@>=
+xfree(mp->theta);
+xfree(mp->uu);
+xfree(mp->vv);
+xfree(mp->ww);
+
+@ @<Declarations@>=
+static void mp_reallocate_paths (MP mp, int l);
+
+@ @c
+void mp_reallocate_paths (MP mp, int l) {
+ XREALLOC (mp->delta_x, l, scaled);
+ XREALLOC (mp->delta_y, l, scaled);
+ XREALLOC (mp->delta, l, scaled);
+ XREALLOC (mp->psi, l, angle);
+ XREALLOC (mp->theta, l, angle);
+ XREALLOC (mp->uu, l, fraction);
+ XREALLOC (mp->vv, l, angle);
+ XREALLOC (mp->ww, l, fraction);
+ mp->path_size = l;
+}
+
+@ Our immediate problem is to get the ball rolling by setting up the
+first equation or by realizing that no equations are needed, and to fit
+this initialization into a framework suitable for the overall computation.
+
+@<Declarations@>=
+static void mp_solve_choices (MP mp,pointer p, pointer q, halfword n) ;
+
+@ @c
+void mp_solve_choices (MP mp,pointer p, pointer q, halfword n) {
+ int k; /* current knot number */
+ pointer r,s,t; /* registers for list traversal */
+ @<Other local variables for |solve_choices|@>;
+ k=0; s=p; r=0;
+ while (1) {
+ t=mp_link(s);
+ if ( k==0 ) {
+ @<Get the linear equations started; or |return|
+ with the control points in place, if linear equations
+ needn't be solved@>
+ } else {
+ switch (mp_left_type(s)) {
+ case mp_end_cycle: case mp_open:
+ @<Set up equation to match mock curvatures
+ at $z_k$; then |goto found| with $\theta_n$
+ adjusted to equal $\theta_0$, if a cycle has ended@>;
+ break;
+ case mp_curl:
+ @<Set up equation for a curl at $\theta_n$
+ and |goto found|@>;
+ break;
+ case mp_given:
+ @<Calculate the given value of $\theta_n$
+ and |goto found|@>;
+ break;
+ } /* there are no other cases */
+ }
+ r=s; s=t; incr(k);
+ }
+FOUND:
+ @<Finish choosing angles and assigning control points@>;
+}
+
+@ On the first time through the loop, we have |k=0| and |r| is not yet
+defined. The first linear equation, if any, will have $A_0=B_0=0$.
+
+@<Get the linear equations started...@>=
+switch (mp_right_type(s)) {
+case mp_given:
+ if ( mp_left_type(t)==mp_given ) {
+ @<Reduce to simple case of two givens and |return|@>
+ } else {
+ @<Set up the equation for a given value of $\theta_0$@>;
+ }
+ break;
+case mp_curl:
+ if ( mp_left_type(t)==mp_curl ) {
+ @<Reduce to simple case of straight line and |return|@>
+ } else {
+ @<Set up the equation for a curl at $\theta_0$@>;
+ }
+ break;
+case mp_open:
+ mp->uu[0]=0; mp->vv[0]=0; mp->ww[0]=fraction_one;
+ /* this begins a cycle */
+ break;
+} /* there are no other cases */
+
+@ The general equation that specifies equality of mock curvature at $z_k$ is
+$$A_k\theta_{k-1}+(B_k+C_k)\theta_k+D_k\theta\k=-B_k\psi_k-D_k\psi\k,$$
+as derived above. We want to combine this with the already-derived equation
+$\theta_{k-1}+u_{k-1}\theta_k=v_{k-1}+w_{k-1}\theta_0$ in order to obtain
+a new equation
+$\theta_k+u_k\theta\k=v_k+w_k\theta_0$. This can be done by dividing the
+equation
+$$(B_k-u_{k-1}A_k+C_k)\theta_k+D_k\theta\k=-B_k\psi_k-D_k\psi\k-A_kv_{k-1}
+ -A_kw_{k-1}\theta_0$$
+by $B_k-u_{k-1}A_k+C_k$. The trick is to do this carefully with
+fixed-point arithmetic, avoiding the chance of overflow while retaining
+suitable precision.
+
+The calculations will be performed in several registers that
+provide temporary storage for intermediate quantities.
+
+@<Other local variables for |solve_choices|@>=
+fraction aa,bb,cc,ff,acc; /* temporary registers */
+scaled dd,ee; /* likewise, but |scaled| */
+scaled lt,rt; /* tension values */
+
+@ @<Set up equation to match mock curvatures...@>=
+{ @<Calculate the values $\\{aa}=A_k/B_k$, $\\{bb}=D_k/C_k$,
+ $\\{dd}=(3-\alpha_{k-1})d_{k,k+1}$, $\\{ee}=(3-\beta\k)d_{k-1,k}$,
+ and $\\{cc}=(B_k-u_{k-1}A_k)/B_k$@>;
+ @<Calculate the ratio $\\{ff}=C_k/(C_k+B_k-u_{k-1}A_k)$@>;
+ mp->uu[k]=mp_take_fraction(mp, ff,bb);
+ @<Calculate the values of $v_k$ and $w_k$@>;
+ if ( mp_left_type(s)==mp_end_cycle ) {
+ @<Adjust $\theta_n$ to equal $\theta_0$ and |goto found|@>;
+ }
+}
+
+@ Since tension values are never less than 3/4, the values |aa| and
+|bb| computed here are never more than 4/5.
+
+@<Calculate the values $\\{aa}=...@>=
+if ( abs(right_tension(r))==unity) {
+ aa=fraction_half; dd=2*mp->delta[k];
+} else {
+ aa=mp_make_fraction(mp, unity,3*abs(right_tension(r))-unity);
+ dd=mp_take_fraction(mp, mp->delta[k],
+ fraction_three-mp_make_fraction(mp, unity,abs(right_tension(r))));
+}
+if ( abs(left_tension(t))==unity ){
+ bb=fraction_half; ee=2*mp->delta[k-1];
+} else {
+ bb=mp_make_fraction(mp, unity,3*abs(left_tension(t))-unity);
+ ee=mp_take_fraction(mp, mp->delta[k-1],
+ fraction_three-mp_make_fraction(mp, unity,abs(left_tension(t))));
+}
+cc=fraction_one-mp_take_fraction(mp, mp->uu[k-1],aa)
+
+@ The ratio to be calculated in this step can be written in the form
+$$\beta_k^2\cdot\\{ee}\over\beta_k^2\cdot\\{ee}+\alpha_k^2\cdot
+ \\{cc}\cdot\\{dd},$$
+because of the quantities just calculated. The values of |dd| and |ee|
+will not be needed after this step has been performed.
+
+@<Calculate the ratio $\\{ff}=C_k/(C_k+B_k-u_{k-1}A_k)$@>=
+dd=mp_take_fraction(mp, dd,cc); lt=abs(left_tension(s)); rt=abs(right_tension(s));
+if ( lt!=rt ) { /* $\beta_k^{-1}\ne\alpha_k^{-1}$ */
+ if ( lt<rt ) {
+ ff=mp_make_fraction(mp, lt,rt);
+ ff=mp_take_fraction(mp, ff,ff); /* $\alpha_k^2/\beta_k^2$ */
+ dd=mp_take_fraction(mp, dd,ff);
+ } else {
+ ff=mp_make_fraction(mp, rt,lt);
+ ff=mp_take_fraction(mp, ff,ff); /* $\beta_k^2/\alpha_k^2$ */
+ ee=mp_take_fraction(mp, ee,ff);
+ }
+}
+ff=mp_make_fraction(mp, ee,ee+dd)
+
+@ The value of $u_{k-1}$ will be |<=1| except when $k=1$ and the previous
+equation was specified by a curl. In that case we must use a special
+method of computation to prevent overflow.
+
+Fortunately, the calculations turn out to be even simpler in this ``hard''
+case. The curl equation makes $w_0=0$ and $v_0=-u_0\psi_1$, hence
+$-B_1\psi_1-A_1v_0=-(B_1-u_0A_1)\psi_1=-\\{cc}\cdot B_1\psi_1$.
+
+@<Calculate the values of $v_k$ and $w_k$@>=
+acc=-mp_take_fraction(mp, mp->psi[k+1],mp->uu[k]);
+if ( mp_right_type(r)==mp_curl ) {
+ mp->ww[k]=0;
+ mp->vv[k]=acc-mp_take_fraction(mp, mp->psi[1],fraction_one-ff);
+} else {
+ ff=mp_make_fraction(mp, fraction_one-ff,cc); /* this is
+ $B_k/(C_k+B_k-u_{k-1}A_k)<5$ */
+ acc=acc-mp_take_fraction(mp, mp->psi[k],ff);
+ ff=mp_take_fraction(mp, ff,aa); /* this is $A_k/(C_k+B_k-u_{k-1}A_k)$ */
+ mp->vv[k]=acc-mp_take_fraction(mp, mp->vv[k-1],ff);
+ if ( mp->ww[k-1]==0 ) mp->ww[k]=0;
+ else mp->ww[k]=-mp_take_fraction(mp, mp->ww[k-1],ff);
+}
+
+@ When a complete cycle has been traversed, we have $\theta_k+u_k\theta\k=
+v_k+w_k\theta_0$, for |1<=k<=n|. We would like to determine the value of
+$\theta_n$ and reduce the system to the form $\theta_k+u_k\theta\k=v_k$
+for |0<=k<n|, so that the cyclic case can be finished up just as if there
+were no cycle.
+
+The idea in the following code is to observe that
+$$\eqalign{\theta_n&=v_n+w_n\theta_0-u_n\theta_1=\cdots\cr
+&=v_n+w_n\theta_0-u_n\bigl(v_1+w_1\theta_0-u_1(v_2+\cdots
+ -u_{n-2}(v_{n-1}+w_{n-1}\theta_0-u_{n-1}\theta_0))\bigr),\cr}$$
+so we can solve for $\theta_n=\theta_0$.
+
+@<Adjust $\theta_n$ to equal $\theta_0$ and |goto found|@>=
+{
+aa=0; bb=fraction_one; /* we have |k=n| */
+do { decr(k);
+if ( k==0 ) k=n;
+ aa=mp->vv[k]-mp_take_fraction(mp, aa,mp->uu[k]);
+ bb=mp->ww[k]-mp_take_fraction(mp, bb,mp->uu[k]);
+} while (k!=n); /* now $\theta_n=\\{aa}+\\{bb}\cdot\theta_n$ */
+aa=mp_make_fraction(mp, aa,fraction_one-bb);
+mp->theta[n]=aa; mp->vv[0]=aa;
+for (k=1;k<n;k++) {
+ mp->vv[k]=mp->vv[k]+mp_take_fraction(mp, aa,mp->ww[k]);
+}
+goto FOUND;
+}
+
+@ @d reduce_angle(A) if ( abs((A))>one_eighty_deg ) {
+ if ( (A)>0 ) (A)=(A)-three_sixty_deg; else (A)=(A)+three_sixty_deg; }
+
+@<Calculate the given value of $\theta_n$...@>=
+{
+ mp->theta[n]=left_given(s)-mp_n_arg(mp, mp->delta_x[n-1],mp->delta_y[n-1]);
+ reduce_angle(mp->theta[n]);
+ goto FOUND;
+}
+
+@ @<Set up the equation for a given value of $\theta_0$@>=
+{
+ mp->vv[0]=right_given(s)-mp_n_arg(mp, mp->delta_x[0],mp->delta_y[0]);
+ reduce_angle(mp->vv[0]);
+ mp->uu[0]=0; mp->ww[0]=0;
+}
+
+@ @<Set up the equation for a curl at $\theta_0$@>=
+{ cc=right_curl(s); lt=abs(left_tension(t)); rt=abs(right_tension(s));
+ if ( (rt==unity)&&(lt==unity) )
+ mp->uu[0]=mp_make_fraction(mp, cc+cc+unity,cc+two);
+ else
+ mp->uu[0]=mp_curl_ratio(mp, cc,rt,lt);
+ mp->vv[0]=-mp_take_fraction(mp, mp->psi[1],mp->uu[0]); mp->ww[0]=0;
+}
+
+@ @<Set up equation for a curl at $\theta_n$...@>=
+{ cc=left_curl(s); lt=abs(left_tension(s)); rt=abs(right_tension(r));
+ if ( (rt==unity)&&(lt==unity) )
+ ff=mp_make_fraction(mp, cc+cc+unity,cc+two);
+ else
+ ff=mp_curl_ratio(mp, cc,lt,rt);
+ mp->theta[n]=-mp_make_fraction(mp, mp_take_fraction(mp, mp->vv[n-1],ff),
+ fraction_one-mp_take_fraction(mp, ff,mp->uu[n-1]));
+ goto FOUND;
+}
+
+@ The |curl_ratio| subroutine has three arguments, which our previous notation
+encourages us to call $\gamma$, $\alpha^{-1}$, and $\beta^{-1}$. It is
+a somewhat tedious program to calculate
+$${(3-\alpha)\alpha^2\gamma+\beta^3\over
+ \alpha^3\gamma+(3-\beta)\beta^2},$$
+with the result reduced to 4 if it exceeds 4. (This reduction of curl
+is necessary only if the curl and tension are both large.)
+The values of $\alpha$ and $\beta$ will be at most~4/3.
+
+@<Declarations@>=
+static fraction mp_curl_ratio (MP mp,scaled gamma, scaled a_tension,
+ scaled b_tension) ;
+
+@ @c
+fraction mp_curl_ratio (MP mp,scaled gamma, scaled a_tension,
+ scaled b_tension) {
+ fraction alpha,beta,num,denom,ff; /* registers */
+ alpha=mp_make_fraction(mp, unity,a_tension);
+ beta=mp_make_fraction(mp, unity,b_tension);
+ if ( alpha<=beta ) {
+ ff=mp_make_fraction(mp, alpha,beta); ff=mp_take_fraction(mp, ff,ff);
+ gamma=mp_take_fraction(mp, gamma,ff);
+ beta=beta / 010000; /* convert |fraction| to |scaled| */
+ denom=mp_take_fraction(mp, gamma,alpha)+three-beta;
+ num=mp_take_fraction(mp, gamma,fraction_three-alpha)+beta;
+ } else {
+ ff=mp_make_fraction(mp, beta,alpha); ff=mp_take_fraction(mp, ff,ff);
+ beta=mp_take_fraction(mp, beta,ff) / 010000; /* convert |fraction| to |scaled| */
+ denom=mp_take_fraction(mp, gamma,alpha)+(ff / 1365)-beta;
+ /* $1365\approx 2^{12}/3$ */
+ num=mp_take_fraction(mp, gamma,fraction_three-alpha)+beta;
+ }
+ if ( num>=denom+denom+denom+denom ) return fraction_four;
+ else return mp_make_fraction(mp, num,denom);
+}
+
+@ We're in the home stretch now.
+
+@<Finish choosing angles and assigning control points@>=
+for (k=n-1;k>=0;k--) {
+ mp->theta[k]=mp->vv[k]-mp_take_fraction(mp,mp->theta[k+1],mp->uu[k]);
+}
+s=p; k=0;
+do {
+ t=mp_link(s);
+ mp_n_sin_cos(mp, mp->theta[k]); mp->st=mp->n_sin; mp->ct=mp->n_cos;
+ mp_n_sin_cos(mp, -mp->psi[k+1]-mp->theta[k+1]); mp->sf=mp->n_sin; mp->cf=mp->n_cos;
+ mp_set_controls(mp, s,t,k);
+ incr(k); s=t;
+} while (k!=n)
+
+@ The |set_controls| routine actually puts the control points into
+a pair of consecutive nodes |p| and~|q|. Global variables are used to
+record the values of $\sin\theta$, $\cos\theta$, $\sin\phi$, and
+$\cos\phi$ needed in this calculation.
+
+@<Glob...@>=
+fraction st;
+fraction ct;
+fraction sf;
+fraction cf; /* sines and cosines */
+
+@ @<Declarations@>=
+static void mp_set_controls (MP mp,pointer p, pointer q, integer k);
+
+@ @c
+void mp_set_controls (MP mp,pointer p, pointer q, integer k) {
+ fraction rr,ss; /* velocities, divided by thrice the tension */
+ scaled lt,rt; /* tensions */
+ fraction sine; /* $\sin(\theta+\phi)$ */
+ lt=abs(left_tension(q)); rt=abs(right_tension(p));
+ rr=mp_velocity(mp, mp->st,mp->ct,mp->sf,mp->cf,rt);
+ ss=mp_velocity(mp, mp->sf,mp->cf,mp->st,mp->ct,lt);
+ if ( (right_tension(p)<0)||(left_tension(q)<0) ) {
+ @<Decrease the velocities,
+ if necessary, to stay inside the bounding triangle@>;
+ }
+ mp_right_x(p)=mp_x_coord(p)+mp_take_fraction(mp,
+ mp_take_fraction(mp, mp->delta_x[k],mp->ct)-
+ mp_take_fraction(mp, mp->delta_y[k],mp->st),rr);
+ mp_right_y(p)=mp_y_coord(p)+mp_take_fraction(mp,
+ mp_take_fraction(mp, mp->delta_y[k],mp->ct)+
+ mp_take_fraction(mp, mp->delta_x[k],mp->st),rr);
+ mp_left_x(q)=mp_x_coord(q)-mp_take_fraction(mp,
+ mp_take_fraction(mp, mp->delta_x[k],mp->cf)+
+ mp_take_fraction(mp, mp->delta_y[k],mp->sf),ss);
+ mp_left_y(q)=mp_y_coord(q)-mp_take_fraction(mp,
+ mp_take_fraction(mp, mp->delta_y[k],mp->cf)-
+ mp_take_fraction(mp, mp->delta_x[k],mp->sf),ss);
+ mp_right_type(p)=mp_explicit; mp_left_type(q)=mp_explicit;
+}
+
+@ The boundedness conditions $\\{rr}\L\sin\phi\,/\sin(\theta+\phi)$ and
+$\\{ss}\L\sin\theta\,/\sin(\theta+\phi)$ are to be enforced if $\sin\theta$,
+$\sin\phi$, and $\sin(\theta+\phi)$ all have the same sign. Otherwise
+there is no ``bounding triangle.''
+
+@<Decrease the velocities, if necessary...@>=
+if (((mp->st>=0)&&(mp->sf>=0))||((mp->st<=0)&&(mp->sf<=0)) ) {
+ sine=mp_take_fraction(mp, abs(mp->st),mp->cf)+
+ mp_take_fraction(mp, abs(mp->sf),mp->ct);
+ if ( sine>0 ) {
+ sine=mp_take_fraction(mp, sine,fraction_one+unity); /* safety factor */
+ if ( right_tension(p)<0 )
+ if ( mp_ab_vs_cd(mp, abs(mp->sf),fraction_one,rr,sine)<0 )
+ rr=mp_make_fraction(mp, abs(mp->sf),sine);
+ if ( left_tension(q)<0 )
+ if ( mp_ab_vs_cd(mp, abs(mp->st),fraction_one,ss,sine)<0 )
+ ss=mp_make_fraction(mp, abs(mp->st),sine);
+ }
+}
+
+@ Only the simple cases remain to be handled.
+
+@<Reduce to simple case of two givens and |return|@>=
+{
+ aa=mp_n_arg(mp, mp->delta_x[0],mp->delta_y[0]);
+ mp_n_sin_cos(mp, right_given(p)-aa); mp->ct=mp->n_cos; mp->st=mp->n_sin;
+ mp_n_sin_cos(mp, left_given(q)-aa); mp->cf=mp->n_cos; mp->sf=-mp->n_sin;
+ mp_set_controls(mp, p,q,0); return;
+}
+
+@ @<Reduce to simple case of straight line and |return|@>=
+{
+ mp_right_type(p)=mp_explicit; mp_left_type(q)=mp_explicit;
+ lt=abs(left_tension(q)); rt=abs(right_tension(p));
+ if ( rt==unity ) {
+ if ( mp->delta_x[0]>=0 ) mp_right_x(p)=mp_x_coord(p)+((mp->delta_x[0]+1) / 3);
+ else mp_right_x(p)=mp_x_coord(p)+((mp->delta_x[0]-1) / 3);
+ if ( mp->delta_y[0]>=0 ) mp_right_y(p)=mp_y_coord(p)+((mp->delta_y[0]+1) / 3);
+ else mp_right_y(p)=mp_y_coord(p)+((mp->delta_y[0]-1) / 3);
+ } else {
+ ff=mp_make_fraction(mp, unity,3*rt); /* $\alpha/3$ */
+ mp_right_x(p)=mp_x_coord(p)+mp_take_fraction(mp, mp->delta_x[0],ff);
+ mp_right_y(p)=mp_y_coord(p)+mp_take_fraction(mp, mp->delta_y[0],ff);
+ }
+ if ( lt==unity ) {
+ if ( mp->delta_x[0]>=0 ) mp_left_x(q)=mp_x_coord(q)-((mp->delta_x[0]+1) / 3);
+ else mp_left_x(q)=mp_x_coord(q)-((mp->delta_x[0]-1) / 3);
+ if ( mp->delta_y[0]>=0 ) mp_left_y(q)=mp_y_coord(q)-((mp->delta_y[0]+1) / 3);
+ else mp_left_y(q)=mp_y_coord(q)-((mp->delta_y[0]-1) / 3);
+ } else {
+ ff=mp_make_fraction(mp, unity,3*lt); /* $\beta/3$ */
+ mp_left_x(q)=mp_x_coord(q)-mp_take_fraction(mp, mp->delta_x[0],ff);
+ mp_left_y(q)=mp_y_coord(q)-mp_take_fraction(mp, mp->delta_y[0],ff);
+ }
+ return;
+}
+
+@* \[19] Measuring paths.
+\MP's \&{llcorner}, \&{lrcorner}, \&{ulcorner}, and \&{urcorner} operators
+allow the user to measure the bounding box of anything that can go into a
+picture. It's easy to get rough bounds on the $x$ and $y$ extent of a path
+by just finding the bounding box of the knots and the control points. We
+need a more accurate version of the bounding box, but we can still use the
+easy estimate to save time by focusing on the interesting parts of the path.
+
+@ Computing an accurate bounding box involves a theme that will come up again
+and again. Given a Bernshte{\u\i}n polynomial
+@^Bernshte{\u\i}n, Serge{\u\i} Natanovich@>
+$$B(z_0,z_1,\ldots,z_n;t)=\sum_k{n\choose k}t^k(1-t)^{n-k}z_k,$$
+we can conveniently bisect its range as follows:
+
+\smallskip
+\textindent{1)} Let $z_k^{(0)}=z_k$, for |0<=k<=n|.
+
+\smallskip
+\textindent{2)} Let $z_k^{(j+1)}={1\over2}(z_k^{(j)}+z\k^{(j)})$, for
+|0<=k<n-j|, for |0<=j<n|.
+
+\smallskip\noindent
+Then
+$$B(z_0,z_1,\ldots,z_n;t)=B(z_0^{(0)},z_0^{(1)},\ldots,z_0^{(n)};2t)
+ =B(z_0^{(n)},z_1^{(n-1)},\ldots,z_n^{(0)};2t-1).$$
+This formula gives us the coefficients of polynomials to use over the ranges
+$0\L t\L{1\over2}$ and ${1\over2}\L t\L1$.
+
+@ Now here's a subroutine that's handy for all sorts of path computations:
+Given a quadratic polynomial $B(a,b,c;t)$, the |crossing_point| function
+returns the unique |fraction| value |t| between 0 and~1 at which
+$B(a,b,c;t)$ changes from positive to negative, or returns
+|t=fraction_one+1| if no such value exists. If |a<0| (so that $B(a,b,c;t)$
+is already negative at |t=0|), |crossing_point| returns the value zero.
+
+@d no_crossing { return (fraction_one+1); }
+@d one_crossing { return fraction_one; }
+@d zero_crossing { return 0; }
+@d mp_crossing_point(M,A,B,C) mp_do_crossing_point(A,B,C)
+
+@c static fraction mp_do_crossing_point (integer a, integer b, integer c) {
+ integer d; /* recursive counter */
+ integer x,xx,x0,x1,x2; /* temporary registers for bisection */
+ if ( a<0 ) zero_crossing;
+ if ( c>=0 ) {
+ if ( b>=0 ) {
+ if ( c>0 ) { no_crossing; }
+ else if ( (a==0)&&(b==0) ) { no_crossing;}
+ else { one_crossing; }
+ }
+ if ( a==0 ) zero_crossing;
+ } else if ( a==0 ) {
+ if ( b<=0 ) zero_crossing;
+ }
+ @<Use bisection to find the crossing point, if one exists@>;
+}
+
+@ The general bisection method is quite simple when $n=2$, hence
+|crossing_point| does not take much time. At each stage in the
+recursion we have a subinterval defined by |l| and~|j| such that
+$B(a,b,c;2^{-l}(j+t))=B(x_0,x_1,x_2;t)$, and we want to ``zero in'' on
+the subinterval where $x_0\G0$ and $\min(x_1,x_2)<0$.
+
+It is convenient for purposes of calculation to combine the values
+of |l| and~|j| in a single variable $d=2^l+j$, because the operation
+of bisection then corresponds simply to doubling $d$ and possibly
+adding~1. Furthermore it proves to be convenient to modify
+our previous conventions for bisection slightly, maintaining the
+variables $X_0=2^lx_0$, $X_1=2^l(x_0-x_1)$, and $X_2=2^l(x_1-x_2)$.
+With these variables the conditions $x_0\ge0$ and $\min(x_1,x_2)<0$ are
+equivalent to $\max(X_1,X_1+X_2)>X_0\ge0$.
+
+The following code maintains the invariant relations
+$0\L|x0|<\max(|x1|,|x1|+|x2|)$,
+$\vert|x1|\vert<2^{30}$, $\vert|x2|\vert<2^{30}$;
+it has been constructed in such a way that no arithmetic overflow
+will occur if the inputs satisfy
+$a<2^{30}$, $\vert a-b\vert<2^{30}$, and $\vert b-c\vert<2^{30}$.
+
+@<Use bisection to find the crossing point...@>=
+d=1; x0=a; x1=a-b; x2=b-c;
+do {
+ x=half(x1+x2);
+ if ( x1-x0>x0 ) {
+ x2=x; x0+=x0; d+=d;
+ } else {
+ xx=x1+x-x0;
+ if ( xx>x0 ) {
+ x2=x; x0+=x0; d+=d;
+ } else {
+ x0=x0-xx;
+ if ( x<=x0 ) { if ( x+x2<=x0 ) no_crossing; }
+ x1=x; d=d+d+1;
+ }
+ }
+} while (d<fraction_one);
+return (d-fraction_one)
+
+@ Here is a routine that computes the $x$ or $y$ coordinate of the point on
+a cubic corresponding to the |fraction| value~|t|.
+
+It is convenient to define a \.{WEB} macro |t_of_the_way| such that
+|t_of_the_way(a,b)| expands to |a-(a-b)*t|, i.e., to |t[a,b]|.
+
+@d t_of_the_way(A,B) ((A)-mp_take_fraction(mp,((A)-(B)),t))
+
+@c static scaled mp_eval_cubic (MP mp,pointer p, pointer q, fraction t) {
+ scaled x1,x2,x3; /* intermediate values */
+ x1=t_of_the_way(knot_coord(p),right_coord(p));
+ x2=t_of_the_way(right_coord(p),left_coord(q));
+ x3=t_of_the_way(left_coord(q),knot_coord(q));
+ x1=t_of_the_way(x1,x2);
+ x2=t_of_the_way(x2,x3);
+ return t_of_the_way(x1,x2);
+}
+
+@ The actual bounding box information is stored in global variables.
+Since it is convenient to address the $x$ and $y$ information
+separately, we define arrays indexed by |x_code..y_code| and use
+macros to give them more convenient names.
+
+@<Types...@>=
+enum mp_bb_code {
+ mp_x_code=0, /* index for |minx| and |maxx| */
+ mp_y_code /* index for |miny| and |maxy| */
+} ;
+
+@
+@d mp_minx mp->bbmin[mp_x_code]
+@d mp_maxx mp->bbmax[mp_x_code]
+@d mp_miny mp->bbmin[mp_y_code]
+@d mp_maxy mp->bbmax[mp_y_code]
+
+@<Glob...@>=
+scaled bbmin[mp_y_code+1];
+scaled bbmax[mp_y_code+1];
+/* the result of procedures that compute bounding box information */
+
+@ Now we're ready for the key part of the bounding box computation.
+The |bound_cubic| procedure updates |bbmin[c]| and |bbmax[c]| based on
+$$B(\hbox{|knot_coord(p)|}, \hbox{|right_coord(p)|},
+ \hbox{|left_coord(q)|}, \hbox{|knot_coord(q)|};t)
+$$
+for $0<t\le1$. In other words, the procedure adjusts the bounds to
+accommodate |knot_coord(q)| and any extremes over the range $0<t<1$.
+The |c| parameter is |x_code| or |y_code|.
+
+@c static void mp_bound_cubic (MP mp,pointer p, pointer q, quarterword c) {
+ boolean wavy; /* whether we need to look for extremes */
+ scaled del1,del2,del3,del,dmax; /* proportional to the control
+ points of a quadratic derived from a cubic */
+ fraction t,tt; /* where a quadratic crosses zero */
+ scaled x; /* a value that |bbmin[c]| and |bbmax[c]| must accommodate */
+ x=knot_coord(q);
+ @<Adjust |bbmin[c]| and |bbmax[c]| to accommodate |x|@>;
+ @<Check the control points against the bounding box and set |wavy:=true|
+ if any of them lie outside@>;
+ if ( wavy ) {
+ del1=right_coord(p)-knot_coord(p);
+ del2=left_coord(q)-right_coord(p);
+ del3=knot_coord(q)-left_coord(q);
+ @<Scale up |del1|, |del2|, and |del3| for greater accuracy;
+ also set |del| to the first nonzero element of |(del1,del2,del3)|@>;
+ if ( del<0 ) {
+ negate(del1); negate(del2); negate(del3);
+ };
+ t=mp_crossing_point(mp, del1,del2,del3);
+ if ( t<fraction_one ) {
+ @<Test the extremes of the cubic against the bounding box@>;
+ }
+ }
+}
+
+@ @<Adjust |bbmin[c]| and |bbmax[c]| to accommodate |x|@>=
+if ( x<mp->bbmin[c] ) mp->bbmin[c]=x;
+if ( x>mp->bbmax[c] ) mp->bbmax[c]=x
+
+@ @<Check the control points against the bounding box and set...@>=
+wavy=true;
+if ( mp->bbmin[c]<=right_coord(p) )
+ if ( right_coord(p)<=mp->bbmax[c] )
+ if ( mp->bbmin[c]<=left_coord(q) )
+ if ( left_coord(q)<=mp->bbmax[c] )
+ wavy=false
+
+@ If |del1=del2=del3=0|, it's impossible to obey the title of this
+section. We just set |del=0| in that case.
+
+@<Scale up |del1|, |del2|, and |del3| for greater accuracy...@>=
+if ( del1!=0 ) del=del1;
+else if ( del2!=0 ) del=del2;
+else del=del3;
+if ( del!=0 ) {
+ dmax=abs(del1);
+ if ( abs(del2)>dmax ) dmax=abs(del2);
+ if ( abs(del3)>dmax ) dmax=abs(del3);
+ while ( dmax<fraction_half ) {
+ dmax+=dmax; del1+=del1; del2+=del2; del3+=del3;
+ }
+}
+
+@ Since |crossing_point| has tried to choose |t| so that
+$B(|del1|,|del2|,|del3|;\tau)$ crosses zero at $\tau=|t|$ with negative
+slope, the value of |del2| computed below should not be positive.
+But rounding error could make it slightly positive in which case we
+must cut it to zero to avoid confusion.
+
+@<Test the extremes of the cubic against the bounding box@>=
+{
+ x=mp_eval_cubic(mp, p,q,t);
+ @<Adjust |bbmin[c]| and |bbmax[c]| to accommodate |x|@>;
+ del2=t_of_the_way(del2,del3);
+ /* now |0,del2,del3| represent the derivative on the remaining interval */
+ if ( del2>0 ) del2=0;
+ tt=mp_crossing_point(mp, 0,-del2,-del3);
+ if ( tt<fraction_one ) {
+ @<Test the second extreme against the bounding box@>;
+ }
+}
+
+@ @<Test the second extreme against the bounding box@>=
+{
+ x=mp_eval_cubic(mp, p,q,t_of_the_way(tt,fraction_one));
+ @<Adjust |bbmin[c]| and |bbmax[c]| to accommodate |x|@>;
+}
+
+@ Finding the bounding box of a path is basically a matter of applying
+|bound_cubic| twice for each pair of adjacent knots.
+
+@c static void mp_path_bbox (MP mp,pointer h) {
+ pointer p,q; /* a pair of adjacent knots */
+ mp_minx=mp_x_coord(h); mp_miny=mp_y_coord(h);
+ mp_maxx=mp_minx; mp_maxy=mp_miny;
+ p=h;
+ do {
+ if ( mp_right_type(p)==mp_endpoint ) return;
+ q=mp_link(p);
+ mp_bound_cubic(mp, x_loc(p),x_loc(q),mp_x_code);
+ mp_bound_cubic(mp, y_loc(p),y_loc(q),mp_y_code);
+ p=q;
+ } while (p!=h);
+}
+
+@ Another important way to measure a path is to find its arc length. This
+is best done by using the general bisection algorithm to subdivide the path
+until obtaining ``well behaved'' subpaths whose arc lengths can be approximated
+by simple means.
+
+Since the arc length is the integral with respect to time of the magnitude of
+the velocity, it is natural to use Simpson's rule for the approximation.
+@^Simpson's rule@>
+If $\dot B(t)$ is the spline velocity, Simpson's rule gives
+$$ \vb\dot B(0)\vb + 4\vb\dot B({1\over2})\vb + \vb\dot B(1)\vb \over 6 $$
+for the arc length of a path of length~1. For a cubic spline
+$B(z_0,z_1,z_2,z_3;t)$, the time derivative $\dot B(t)$ is
+$3B(dz_0,dz_1,dz_2;t)$, where $dz_i=z_{i+1}-z_i$. Hence the arc length
+approximation is
+$$ {\vb dz_0\vb \over 2} + 2\vb dz_{02}\vb + {\vb dz_2\vb \over 2}, $$
+where
+$$ dz_{02}={1\over2}\left({dz_0+dz_1\over 2}+{dz_1+dz_2\over 2}\right)$$
+is the result of the bisection algorithm.
+
+@ The remaining problem is how to decide when a subpath is ``well behaved.''
+This could be done via the theoretical error bound for Simpson's rule,
+@^Simpson's rule@>
+but this is impractical because it requires an estimate of the fourth
+derivative of the quantity being integrated. It is much easier to just perform
+a bisection step and see how much the arc length estimate changes. Since the
+error for Simpson's rule is proportional to the fourth power of the sample
+spacing, the remaining error is typically about $1\over16$ of the amount of
+the change. We say ``typically'' because the error has a pseudo-random behavior
+that could cause the two estimates to agree when each contain large errors.
+
+To protect against disasters such as undetected cusps, the bisection process
+should always continue until all the $dz_i$ vectors belong to a single
+$90^\circ$ sector. This ensures that no point on the spline can have velocity
+less than 70\% of the minimum of $\vb dz_0\vb$, $\vb dz_1\vb$ and $\vb dz_2\vb$.
+If such a spline happens to produce an erroneous arc length estimate that
+is little changed by bisection, the amount of the error is likely to be fairly
+small. We will try to arrange things so that freak accidents of this type do
+not destroy the inverse relationship between the \&{arclength} and
+\&{arctime} operations.
+@:arclength_}{\&{arclength} primitive@>
+@:arctime_}{\&{arctime} primitive@>
+
+@ The \&{arclength} and \&{arctime} operations are both based on a recursive
+@^recursion@>
+function that finds the arc length of a cubic spline given $dz_0$, $dz_1$,
+$dz_2$. This |arc_test| routine also takes an arc length goal |a_goal| and
+returns the time when the arc length reaches |a_goal| if there is such a time.
+Thus the return value is either an arc length less than |a_goal| or, if the
+arc length would be at least |a_goal|, it returns a time value decreased by
+|two|. This allows the caller to use the sign of the result to distinguish
+between arc lengths and time values. On certain types of overflow, it is
+possible for |a_goal| and the result of |arc_test| both to be |el_gordo|.
+Otherwise, the result is always less than |a_goal|.
+
+Rather than halving the control point coordinates on each recursive call to
+|arc_test|, it is better to keep them proportional to velocity on the original
+curve and halve the results instead. This means that recursive calls can
+potentially use larger error tolerances in their arc length estimates. How
+much larger depends on to what extent the errors behave as though they are
+independent of each other. To save computing time, we use optimistic assumptions
+and increase the tolerance by a factor of about $\sqrt2$ for each recursive
+call.
+
+In addition to the tolerance parameter, |arc_test| should also have parameters
+for ${1\over3}\vb\dot B(0)\vb$, ${2\over3}\vb\dot B({1\over2})\vb$, and
+${1\over3}\vb\dot B(1)\vb$. These quantities are relatively expensive to compute
+and they are needed in different instances of |arc_test|.
+
+@c
+static scaled mp_arc_test (MP mp, scaled dx0, scaled dy0, scaled dx1, scaled dy1,
+ scaled dx2, scaled dy2, scaled v0, scaled v02,
+ scaled v2, scaled a_goal, scaled tol) {
+ boolean simple; /* are the control points confined to a $90^\circ$ sector? */
+ scaled dx01, dy01, dx12, dy12, dx02, dy02; /* bisection results */
+ scaled v002, v022;
+ /* twice the velocity magnitudes at $t={1\over4}$ and $t={3\over4}$ */
+ scaled arc; /* best arc length estimate before recursion */
+ @<Other local variables in |arc_test|@>;
+ @<Bisect the B\'ezier quadratic given by |dx0|, |dy0|, |dx1|, |dy1|,
+ |dx2|, |dy2|@>;
+ @<Initialize |v002|, |v022|, and the arc length estimate |arc|; if it overflows
+ set |arc_test| and |return|@>;
+ @<Test if the control points are confined to one quadrant or rotating them
+ $45^\circ$ would put them in one quadrant. Then set |simple| appropriately@>;
+ if ( simple && (abs(arc-v02-halfp(v0+v2)) <= tol) ) {
+ if ( arc < a_goal ) {
+ return arc;
+ } else {
+ @<Estimate when the arc length reaches |a_goal| and set |arc_test| to
+ that time minus |two|@>;
+ }
+ } else {
+ @<Use one or two recursive calls to compute the |arc_test| function@>;
+ }
+}
+
+@ The |tol| value should by multiplied by $\sqrt 2$ before making recursive
+calls, but $1.5$ is an adequate approximation. It is best to avoid using
+|make_fraction| in this inner loop.
+@^inner loop@>
+
+@<Use one or two recursive calls to compute the |arc_test| function@>=
+{
+ @<Set |a_new| and |a_aux| so their sum is |2*a_goal| and |a_new| is as
+ large as possible@>;
+ tol = tol + halfp(tol);
+ a = mp_arc_test(mp, dx0,dy0, dx01,dy01, dx02,dy02, v0, v002,
+ halfp(v02), a_new, tol);
+ if ( a<0 ) {
+ return (-halfp(two-a));
+ } else {
+ @<Update |a_new| to reduce |a_new+a_aux| by |a|@>;
+ b = mp_arc_test(mp, dx02,dy02, dx12,dy12, dx2,dy2,
+ halfp(v02), v022, v2, a_new, tol);
+ if ( b<0 )
+ return (-halfp(-b) - half_unit);
+ else
+ return (a + half(b-a));
+ }
+}
+
+@ @<Other local variables in |arc_test|@>=
+scaled a,b; /* results of recursive calls */
+scaled a_new,a_aux; /* the sum of these gives the |a_goal| */
+
+@ @<Set |a_new| and |a_aux| so their sum is |2*a_goal| and |a_new| is...@>=
+a_aux = el_gordo - a_goal;
+if ( a_goal > a_aux ) {
+ a_aux = a_goal - a_aux;
+ a_new = el_gordo;
+} else {
+ a_new = a_goal + a_goal;
+ a_aux = 0;
+}
+
+@ There is no need to maintain |a_aux| at this point so we use it as a temporary
+to force the additions and subtractions to be done in an order that avoids
+overflow.
+
+@<Update |a_new| to reduce |a_new+a_aux| by |a|@>=
+if ( a > a_aux ) {
+ a_aux = a_aux - a;
+ a_new = a_new + a_aux;
+}
+
+@ This code assumes all {\it dx} and {\it dy} variables have magnitude less than
+|fraction_four|. To simplify the rest of the |arc_test| routine, we strengthen
+this assumption by requiring the norm of each $({\it dx},{\it dy})$ pair to obey
+this bound. Note that recursive calls will maintain this invariant.
+
+@<Bisect the B\'ezier quadratic given by |dx0|, |dy0|, |dx1|, |dy1|,...@>=
+dx01 = half(dx0 + dx1);
+dx12 = half(dx1 + dx2);
+dx02 = half(dx01 + dx12);
+dy01 = half(dy0 + dy1);
+dy12 = half(dy1 + dy2);
+dy02 = half(dy01 + dy12)
+
+@ We should be careful to keep |arc<el_gordo| so that calling |arc_test| with
+|a_goal=el_gordo| is guaranteed to yield the arc length.
+
+@<Initialize |v002|, |v022|, and the arc length estimate |arc|;...@>=
+v002 = mp_pyth_add(mp, dx01+half(dx0+dx02), dy01+half(dy0+dy02));
+v022 = mp_pyth_add(mp, dx12+half(dx02+dx2), dy12+half(dy02+dy2));
+tmp = halfp(v02+2);
+arc1 = v002 + half(halfp(v0+tmp) - v002);
+arc = v022 + half(halfp(v2+tmp) - v022);
+if ( (arc < el_gordo-arc1) ) {
+ arc = arc+arc1;
+} else {
+ mp->arith_error = true;
+ if ( a_goal==el_gordo ) return (el_gordo);
+ else return (-two);
+}
+
+@ @<Other local variables in |arc_test|@>=
+scaled tmp, tmp2; /* all purpose temporary registers */
+scaled arc1; /* arc length estimate for the first half */
+
+@ @<Test if the control points are confined to one quadrant or rotating...@>=
+simple = ((dx0>=0) && (dx1>=0) && (dx2>=0)) ||
+ ((dx0<=0) && (dx1<=0) && (dx2<=0));
+if ( simple )
+ simple = ((dy0>=0) && (dy1>=0) && (dy2>=0)) ||
+ ((dy0<=0) && (dy1<=0) && (dy2<=0));
+if ( ! simple ) {
+ simple = ((dx0>=dy0) && (dx1>=dy1) && (dx2>=dy2)) ||
+ ((dx0<=dy0) && (dx1<=dy1) && (dx2<=dy2));
+ if ( simple )
+ simple = ((-dx0>=dy0) && (-dx1>=dy1) && (-dx2>=dy2)) ||
+ ((-dx0<=dy0) && (-dx1<=dy1) && (-dx2<=dy2));
+}
+
+@ Since Simpson's rule is based on approximating the integrand by a parabola,
+@^Simpson's rule@>
+it is appropriate to use the same approximation to decide when the integral
+reaches the intermediate value |a_goal|. At this point
+$$\eqalign{
+ {\vb\dot B(0)\vb\over 3} &= \hbox{|v0|}, \qquad
+ {\vb\dot B({1\over4})\vb\over 3} = {\hbox{|v002|}\over 2}, \qquad
+ {\vb\dot B({1\over2})\vb\over 3} = {\hbox{|v02|}\over 2}, \cr
+ {\vb\dot B({3\over4})\vb\over 3} &= {\hbox{|v022|}\over 2}, \qquad
+ {\vb\dot B(1)\vb\over 3} = \hbox{|v2|} \cr
+}
+$$
+and
+$$ {\vb\dot B(t)\vb\over 3} \approx
+ \cases{B\left(\hbox{|v0|},
+ \hbox{|v002|}-{1\over 2}\hbox{|v0|}-{1\over 4}\hbox{|v02|},
+ {1\over 2}\hbox{|v02|}; 2t \right)&
+ if $t\le{1\over 2}$\cr
+ B\left({1\over 2}\hbox{|v02|},
+ \hbox{|v022|}-{1\over 4}\hbox{|v02|}-{1\over 2}\hbox{|v2|},
+ \hbox{|v2|}; 2t-1 \right)&
+ if $t\ge{1\over 2}$.\cr}
+ \eqno (*)
+$$
+We can integrate $\vb\dot B(t)\vb$ by using
+$$\int 3B(a,b,c;\tau)\,dt =
+ {B(0,a,a+b,a+b+c;\tau) + {\rm constant} \over {d\tau\over dt}}.
+$$
+
+This construction allows us to find the time when the arc length reaches
+|a_goal| by solving a cubic equation of the form
+$$ B(0,a,a+b,a+b+c;\tau) = x, $$
+where $\tau$ is $2t$ or $2t+1$, $x$ is |a_goal| or |a_goal-arc1|, and $a$, $b$,
+and $c$ are the Bernshte{\u\i}n coefficients from $(*)$ divided by
+@^Bernshte{\u\i}n, Serge{\u\i} Natanovich@>
+$d\tau\over dt$. We shall define a function |solve_rising_cubic| that finds
+$\tau$ given $a$, $b$, $c$, and $x$.
+
+@<Estimate when the arc length reaches |a_goal| and set |arc_test| to...@>=
+{
+ tmp = (v02 + 2) / 4;
+ if ( a_goal<=arc1 ) {
+ tmp2 = halfp(v0);
+ return
+ (halfp(mp_solve_rising_cubic(mp, tmp2, arc1-tmp2-tmp, tmp, a_goal))- two);
+ } else {
+ tmp2 = halfp(v2);
+ return ((half_unit - two) +
+ halfp(mp_solve_rising_cubic(mp, tmp, arc-arc1-tmp-tmp2, tmp2, a_goal-arc1)));
+ }
+}
+
+@ Here is the |solve_rising_cubic| routine that finds the time~$t$ when
+$$ B(0, a, a+b, a+b+c; t) = x. $$
+This routine is based on |crossing_point| but is simplified by the
+assumptions that $B(a,b,c;t)\ge0$ for $0\le t\le1$ and that |0<=x<=a+b+c|.
+If rounding error causes this condition to be violated slightly, we just ignore
+it and proceed with binary search. This finds a time when the function value
+reaches |x| and the slope is positive.
+
+@<Declarations@>=
+static scaled mp_solve_rising_cubic (MP mp,scaled a, scaled b, scaled c, scaled x) ;
+
+@ @c
+scaled mp_solve_rising_cubic (MP mp,scaled a, scaled b, scaled c, scaled x) {
+ scaled ab, bc, ac; /* bisection results */
+ integer t; /* $2^k+q$ where unscaled answer is in $[q2^{-k},(q+1)2^{-k})$ */
+ integer xx; /* temporary for updating |x| */
+ if ( (a<0) || (c<0) ) mp_confusion(mp, "rising?");
+@:this can't happen rising?}{\quad rising?@>
+ if ( x<=0 ) {
+ return 0;
+ } else if ( x >= a+b+c ) {
+ return unity;
+ } else {
+ t = 1;
+ @<Rescale if necessary to make sure |a|, |b|, and |c| are all less than
+ |el_gordo div 3|@>;
+ do {
+ t+=t;
+ @<Subdivide the B\'ezier quadratic defined by |a|, |b|, |c|@>;
+ xx = x - a - ab - ac;
+ if ( xx < -x ) { x+=x; b=ab; c=ac; }
+ else { x = x + xx; a=ac; b=bc; t = t+1; };
+ } while (t < unity);
+ return (t - unity);
+ }
+}
+
+@ @<Subdivide the B\'ezier quadratic defined by |a|, |b|, |c|@>=
+ab = half(a+b);
+bc = half(b+c);
+ac = half(ab+bc)
+
+@ @d one_third_el_gordo 05252525252 /* upper bound on |a|, |b|, and |c| */
+
+@<Rescale if necessary to make sure |a|, |b|, and |c| are all less than...@>=
+while ((a>one_third_el_gordo)||(b>one_third_el_gordo)||(c>one_third_el_gordo)) {
+ a = halfp(a);
+ b = half(b);
+ c = halfp(c);
+ x = halfp(x);
+}
+
+@ It is convenient to have a simpler interface to |arc_test| that requires no
+unnecessary arguments and ensures that each $({\it dx},{\it dy})$ pair has
+length less than |fraction_four|.
+
+@d arc_tol 16 /* quit when change in arc length estimate reaches this */
+
+@c static scaled mp_do_arc_test (MP mp,scaled dx0, scaled dy0, scaled dx1,
+ scaled dy1, scaled dx2, scaled dy2, scaled a_goal) {
+ scaled v0,v1,v2; /* length of each $({\it dx},{\it dy})$ pair */
+ scaled v02; /* twice the norm of the quadratic at $t={1\over2}$ */
+ v0 = mp_pyth_add(mp, dx0,dy0);
+ v1 = mp_pyth_add(mp, dx1,dy1);
+ v2 = mp_pyth_add(mp, dx2,dy2);
+ if ( (v0>=fraction_four) || (v1>=fraction_four) || (v2>=fraction_four) ) {
+ mp->arith_error = true;
+ if ( a_goal==el_gordo ) return el_gordo;
+ else return (-two);
+ } else {
+ v02 = mp_pyth_add(mp, dx1+half(dx0+dx2), dy1+half(dy0+dy2));
+ return (mp_arc_test(mp, dx0,dy0, dx1,dy1, dx2,dy2,
+ v0, v02, v2, a_goal, arc_tol));
+ }
+}
+
+@ Now it is easy to find the arc length of an entire path.
+
+@c static scaled mp_get_arc_length (MP mp,pointer h) {
+ pointer p,q; /* for traversing the path */
+ scaled a,a_tot; /* current and total arc lengths */
+ a_tot = 0;
+ p = h;
+ while ( mp_right_type(p)!=mp_endpoint ){
+ q = mp_link(p);
+ a = mp_do_arc_test(mp, mp_right_x(p)-mp_x_coord(p), mp_right_y(p)-mp_y_coord(p),
+ mp_left_x(q)-mp_right_x(p), mp_left_y(q)-mp_right_y(p),
+ mp_x_coord(q)-mp_left_x(q), mp_y_coord(q)-mp_left_y(q), el_gordo);
+ a_tot = mp_slow_add(mp, a, a_tot);
+ if ( q==h ) break; else p=q;
+ }
+ check_arith;
+ return a_tot;
+}
+
+@ The inverse operation of finding the time on a path~|h| when the arc length
+reaches some value |arc0| can also be accomplished via |do_arc_test|. Some care
+is required to handle very large times or negative times on cyclic paths. For
+non-cyclic paths, |arc0| values that are negative or too large cause
+|get_arc_time| to return 0 or the length of path~|h|.
+
+If |arc0| is greater than the arc length of a cyclic path~|h|, the result is a
+time value greater than the length of the path. Since it could be much greater,
+we must be prepared to compute the arc length of path~|h| and divide this into
+|arc0| to find how many multiples of the length of path~|h| to add.
+
+@c static scaled mp_get_arc_time (MP mp,pointer h, scaled arc0) {
+ pointer p,q; /* for traversing the path */
+ scaled t_tot; /* accumulator for the result */
+ scaled t; /* the result of |do_arc_test| */
+ scaled arc; /* portion of |arc0| not used up so far */
+ integer n; /* number of extra times to go around the cycle */
+ if ( arc0<0 ) {
+ @<Deal with a negative |arc0| value and |return|@>;
+ }
+ if ( arc0==el_gordo ) decr(arc0);
+ t_tot = 0;
+ arc = arc0;
+ p = h;
+ while ( (mp_right_type(p)!=mp_endpoint) && (arc>0) ) {
+ q = mp_link(p);
+ t = mp_do_arc_test(mp, mp_right_x(p)-mp_x_coord(p), mp_right_y(p)-mp_y_coord(p),
+ mp_left_x(q)-mp_right_x(p), mp_left_y(q)-mp_right_y(p),
+ mp_x_coord(q)-mp_left_x(q), mp_y_coord(q)-mp_left_y(q), arc);
+ @<Update |arc| and |t_tot| after |do_arc_test| has just returned |t|@>;
+ if ( q==h ) {
+ @<Update |t_tot| and |arc| to avoid going around the cyclic
+ path too many times but set |arith_error:=true| and |goto done| on
+ overflow@>;
+ }
+ p = q;
+ }
+ check_arith;
+ return t_tot;
+}
+
+@ @<Update |arc| and |t_tot| after |do_arc_test| has just returned |t|@>=
+if ( t<0 ) { t_tot = t_tot + t + two; arc = 0; }
+else { t_tot = t_tot + unity; arc = arc - t; }
+
+@ @<Deal with a negative |arc0| value and |return|@>=
+{
+ if ( mp_left_type(h)==mp_endpoint ) {
+ t_tot=0;
+ } else {
+ p = mp_htap_ypoc(mp, h);
+ t_tot = -mp_get_arc_time(mp, p, -arc0);
+ mp_toss_knot_list(mp, p);
+ }
+ check_arith;
+ return t_tot;
+}
+
+@ @<Update |t_tot| and |arc| to avoid going around the cyclic...@>=
+if ( arc>0 ) {
+ n = arc / (arc0 - arc);
+ arc = arc - n*(arc0 - arc);
+ if ( t_tot > (el_gordo / (n+1)) ) {
+ return el_gordo;
+ }
+ t_tot = (n + 1)*t_tot;
+}
+
+@* \[20] Data structures for pens.
+A Pen in \MP\ can be either elliptical or polygonal. Elliptical pens result
+in \ps\ \&{stroke} commands, while anything drawn with a polygonal pen is
+@:stroke}{\&{stroke} command@>
+converted into an area fill as described in the next part of this program.
+The mathematics behind this process is based on simple aspects of the theory
+of tracings developed by Leo Guibas, Lyle Ramshaw, and Jorge Stolfi
+[``A kinematic framework for computational geometry,'' Proc.\ IEEE Symp.\
+Foundations of Computer Science {\bf 24} (1983), 100--111].
+
+Polygonal pens are created from paths via \MP's \&{makepen} primitive.
+@:makepen_}{\&{makepen} primitive@>
+This path representation is almost sufficient for our purposes except that
+a pen path should always be a convex polygon with the vertices in
+counter-clockwise order.
+Since we will need to scan pen polygons both forward and backward, a pen
+should be represented as a doubly linked ring of knot nodes. There is
+room for the extra back pointer because we do not need the
+|mp_left_type| or |mp_right_type| fields. In fact, we don't need the |mp_left_x|,
+|mp_left_y|, |mp_right_x|, or |mp_right_y| fields either but we leave these alone
+so that certain procedures can operate on both pens and paths. In particular,
+pens can be copied using |copy_path| and recycled using |toss_knot_list|.
+
+@d knil mp_info
+ /* this replaces the |mp_left_type| and |mp_right_type| fields in a pen knot */
+
+@ The |make_pen| procedure turns a path into a pen by initializing
+the |knil| pointers and making sure the knots form a convex polygon.
+Thus each cubic in the given path becomes a straight line and the control
+points are ignored. If the path is not cyclic, the ends are connected by a
+straight line.
+
+@d copy_pen(A) mp_make_pen(mp, mp_copy_path(mp, (A)),false)
+
+@c
+static pointer mp_make_pen (MP mp,pointer h, boolean need_hull) {
+ pointer p,q; /* two consecutive knots */
+ q=h;
+ do {
+ p=q; q=mp_link(q);
+ knil(q)=p;
+ } while (q!=h);
+ if ( need_hull ){
+ h=mp_convex_hull(mp, h);
+ @<Make sure |h| isn't confused with an elliptical pen@>;
+ }
+ return h;
+}
+
+@ The only information required about an elliptical pen is the overall
+transformation that has been applied to the original \&{pencircle}.
+@:pencircle_}{\&{pencircle} primitive@>
+Since it suffices to keep track of how the three points $(0,0)$, $(1,0)$,
+and $(0,1)$ are transformed, an elliptical pen can be stored in a single
+knot node and transformed as if it were a path.
+
+@d pen_is_elliptical(A) ((A)==mp_link((A)))
+
+@c
+static pointer mp_get_pen_circle (MP mp,scaled diam) {
+ pointer h; /* the knot node to return */
+ h=mp_get_node(mp, knot_node_size);
+ mp_link(h)=h; knil(h)=h;
+ mp_originator(h)=mp_program_code;
+ mp_x_coord(h)=0; mp_y_coord(h)=0;
+ mp_left_x(h)=diam; mp_left_y(h)=0;
+ mp_right_x(h)=0; mp_right_y(h)=diam;
+ return h;
+}
+
+@ If the polygon being returned by |make_pen| has only one vertex, it will
+be interpreted as an elliptical pen. This is no problem since a degenerate
+polygon can equally well be thought of as a degenerate ellipse. We need only
+initialize the |mp_left_x|, |mp_left_y|, |mp_right_x|, and |mp_right_y| fields.
+
+@<Make sure |h| isn't confused with an elliptical pen@>=
+if ( pen_is_elliptical( h) ){
+ mp_left_x(h)=mp_x_coord(h); mp_left_y(h)=mp_y_coord(h);
+ mp_right_x(h)=mp_x_coord(h); mp_right_y(h)=mp_y_coord(h);
+}
+
+@ Printing a polygonal pen is very much like printing a path
+
+@<Declarations@>=
+static void mp_pr_pen (MP mp,pointer h) ;
+
+@ @c
+void mp_pr_pen (MP mp,pointer h) {
+ pointer p,q; /* for list traversal */
+ if ( pen_is_elliptical(h) ) {
+ @<Print the elliptical pen |h|@>;
+ } else {
+ p=h;
+ do {
+ mp_print_two(mp, mp_x_coord(p),mp_y_coord(p));
+ mp_print_nl(mp, " .. ");
+ @<Advance |p| making sure the links are OK and |return| if there is
+ a problem@>;
+ } while (p!=h);
+ mp_print(mp, "cycle");
+ }
+}
+
+@ @<Advance |p| making sure the links are OK and |return| if there is...@>=
+q=mp_link(p);
+if ( (q==null) || (knil(q)!=p) ) {
+ mp_print_nl(mp, "???"); return; /* this won't happen */
+@.???@>
+}
+p=q
+
+@ @<Print the elliptical pen |h|@>=
+{
+mp_print(mp, "pencircle transformed (");
+mp_print_scaled(mp, mp_x_coord(h));
+mp_print_char(mp, xord(','));
+mp_print_scaled(mp, mp_y_coord(h));
+mp_print_char(mp, xord(','));
+mp_print_scaled(mp, mp_left_x(h)-mp_x_coord(h));
+mp_print_char(mp, xord(','));
+mp_print_scaled(mp, mp_right_x(h)-mp_x_coord(h));
+mp_print_char(mp, xord(','));
+mp_print_scaled(mp, mp_left_y(h)-mp_y_coord(h));
+mp_print_char(mp, xord(','));
+mp_print_scaled(mp, mp_right_y(h)-mp_y_coord(h));
+mp_print_char(mp, xord(')'));
+}
+
+@ Here us another version of |pr_pen| that prints the pen as a diagnostic
+message.
+
+@<Declarations@>=
+static void mp_print_pen (MP mp,pointer h, const char *s, boolean nuline) ;
+
+@ @c
+void mp_print_pen (MP mp,pointer h, const char *s, boolean nuline) {
+ mp_print_diagnostic(mp, "Pen",s,nuline); mp_print_ln(mp);
+@.Pen at line...@>
+ mp_pr_pen(mp, h);
+ mp_end_diagnostic(mp, true);
+}
+
+@ Making a polygonal pen into a path involves restoring the |mp_left_type| and
+|mp_right_type| fields and setting the control points so as to make a polygonal
+path.
+
+@c
+static void mp_make_path (MP mp,pointer h) {
+ pointer p; /* for traversing the knot list */
+ quarterword k; /* a loop counter */
+ @<Other local variables in |make_path|@>;
+ if ( pen_is_elliptical(h) ) {
+ @<Make the elliptical pen |h| into a path@>;
+ } else {
+ p=h;
+ do {
+ mp_left_type(p)=mp_explicit;
+ mp_right_type(p)=mp_explicit;
+ @<copy the coordinates of knot |p| into its control points@>;
+ p=mp_link(p);
+ } while (p!=h);
+ }
+}
+
+@ @<copy the coordinates of knot |p| into its control points@>=
+mp_left_x(p)=mp_x_coord(p);
+mp_left_y(p)=mp_y_coord(p);
+mp_right_x(p)=mp_x_coord(p);
+mp_right_y(p)=mp_y_coord(p)
+
+@ We need an eight knot path to get a good approximation to an ellipse.
+
+@<Make the elliptical pen |h| into a path@>=
+{
+ @<Extract the transformation parameters from the elliptical pen~|h|@>;
+ p=h;
+ for (k=0;k<=7;k++ ) {
+ @<Initialize |p| as the |k|th knot of a circle of unit diameter,
+ transforming it appropriately@>;
+ if ( k==7 ) mp_link(p)=h; else mp_link(p)=mp_get_node(mp, knot_node_size);
+ p=mp_link(p);
+ }
+}
+
+@ @<Extract the transformation parameters from the elliptical pen~|h|@>=
+center_x=mp_x_coord(h);
+center_y=mp_y_coord(h);
+width_x=mp_left_x(h)-center_x;
+width_y=mp_left_y(h)-center_y;
+height_x=mp_right_x(h)-center_x;
+height_y=mp_right_y(h)-center_y
+
+@ @<Other local variables in |make_path|@>=
+scaled center_x,center_y; /* translation parameters for an elliptical pen */
+scaled width_x,width_y; /* the effect of a unit change in $x$ */
+scaled height_x,height_y; /* the effect of a unit change in $y$ */
+scaled dx,dy; /* the vector from knot |p| to its right control point */
+integer kk;
+ /* |k| advanced $270^\circ$ around the ring (cf. $\sin\theta=\cos(\theta+270)$) */
+
+@ The only tricky thing here are the tables |half_cos| and |d_cos| used to
+find the point $k/8$ of the way around the circle and the direction vector
+to use there.
+
+@<Initialize |p| as the |k|th knot of a circle of unit diameter,...@>=
+kk=(k+6)% 8;
+mp_x_coord(p)=center_x+mp_take_fraction(mp, mp->half_cos[k],width_x)
+ +mp_take_fraction(mp, mp->half_cos[kk],height_x);
+mp_y_coord(p)=center_y+mp_take_fraction(mp, mp->half_cos[k],width_y)
+ +mp_take_fraction(mp, mp->half_cos[kk],height_y);
+dx=-mp_take_fraction(mp, mp->d_cos[kk],width_x)
+ +mp_take_fraction(mp, mp->d_cos[k],height_x);
+dy=-mp_take_fraction(mp, mp->d_cos[kk],width_y)
+ +mp_take_fraction(mp, mp->d_cos[k],height_y);
+mp_right_x(p)=mp_x_coord(p)+dx;
+mp_right_y(p)=mp_y_coord(p)+dy;
+mp_left_x(p)=mp_x_coord(p)-dx;
+mp_left_y(p)=mp_y_coord(p)-dy;
+mp_left_type(p)=mp_explicit;
+mp_right_type(p)=mp_explicit;
+mp_originator(p)=mp_program_code
+
+@ @<Glob...@>=
+fraction half_cos[8]; /* ${1\over2}\cos(45k)$ */
+fraction d_cos[8]; /* a magic constant times $\cos(45k)$ */
+
+@ The magic constant for |d_cos| is the distance between $({1\over2},0)$ and
+$({1\over4}\sqrt2,{1\over4}\sqrt2)$ times the result of the |velocity|
+function for $\theta=\phi=22.5^\circ$. This comes out to be
+$$ d = {\sqrt{2-\sqrt2}\over 3+3\cos22.5^\circ}
+ \approx 0.132608244919772.
+$$
+
+@<Set init...@>=
+mp->half_cos[0]=fraction_half;
+mp->half_cos[1]=94906266; /* $2^{26}\sqrt2\approx94906265.62$ */
+mp->half_cos[2]=0;
+mp->d_cos[0]=35596755; /* $2^{28}d\approx35596754.69$ */
+mp->d_cos[1]=25170707; /* $2^{27}\sqrt2\,d\approx25170706.63$ */
+mp->d_cos[2]=0;
+for (k=3;k<= 4;k++ ) {
+ mp->half_cos[k]=-mp->half_cos[4-k];
+ mp->d_cos[k]=-mp->d_cos[4-k];
+}
+for (k=5;k<= 7;k++ ) {
+ mp->half_cos[k]=mp->half_cos[8-k];
+ mp->d_cos[k]=mp->d_cos[8-k];
+}
+
+@ The |convex_hull| function forces a pen polygon to be convex when it is
+returned by |make_pen| and after any subsequent transformation where rounding
+error might allow the convexity to be lost.
+The convex hull algorithm used here is described by F.~P. Preparata and
+M.~I. Shamos [{\sl Computational Geometry}, Springer-Verlag, 1985].
+
+@<Declarations@>=
+static pointer mp_convex_hull (MP mp,pointer h);
+
+@ @c
+pointer mp_convex_hull (MP mp,pointer h) { /* Make a polygonal pen convex */
+ pointer l,r; /* the leftmost and rightmost knots */
+ pointer p,q; /* knots being scanned */
+ pointer s; /* the starting point for an upcoming scan */
+ scaled dx,dy; /* a temporary pointer */
+ if ( pen_is_elliptical(h) ) {
+ return h;
+ } else {
+ @<Set |l| to the leftmost knot in polygon~|h|@>;
+ @<Set |r| to the rightmost knot in polygon~|h|@>;
+ if ( l!=r ) {
+ s=mp_link(r);
+ @<Find any knots on the path from |l| to |r| above the |l|-|r| line and
+ move them past~|r|@>;
+ @<Find any knots on the path from |s| to |l| below the |l|-|r| line and
+ move them past~|l|@>;
+ @<Sort the path from |l| to |r| by increasing $x$@>;
+ @<Sort the path from |r| to |l| by decreasing $x$@>;
+ }
+ if ( l!=mp_link(l) ) {
+ @<Do a Gramm scan and remove vertices where there is no left turn@>;
+ }
+ return l;
+ }
+}
+
+@ All comparisons are done primarily on $x$ and secondarily on $y$.
+
+@<Set |l| to the leftmost knot in polygon~|h|@>=
+l=h;
+p=mp_link(h);
+while ( p!=h ) {
+ if ( mp_x_coord(p)<=mp_x_coord(l) )
+ if ( (mp_x_coord(p)<mp_x_coord(l)) || (mp_y_coord(p)<mp_y_coord(l)) )
+ l=p;
+ p=mp_link(p);
+}
+
+@ @<Set |r| to the rightmost knot in polygon~|h|@>=
+r=h;
+p=mp_link(h);
+while ( p!=h ) {
+ if ( mp_x_coord(p)>=mp_x_coord(r) )
+ if ( (mp_x_coord(p)>mp_x_coord(r)) || (mp_y_coord(p)>mp_y_coord(r)) )
+ r=p;
+ p=mp_link(p);
+}
+
+@ @<Find any knots on the path from |l| to |r| above the |l|-|r| line...@>=
+dx=mp_x_coord(r)-mp_x_coord(l);
+dy=mp_y_coord(r)-mp_y_coord(l);
+p=mp_link(l);
+while ( p!=r ) {
+ q=mp_link(p);
+ if ( mp_ab_vs_cd(mp, dx,mp_y_coord(p)-mp_y_coord(l),dy,mp_x_coord(p)-mp_x_coord(l))>0 )
+ mp_move_knot(mp, p, r);
+ p=q;
+}
+
+@ The |move_knot| procedure removes |p| from a doubly linked list and inserts
+it after |q|.
+
+@ @<Declarations@>=
+static void mp_move_knot (MP mp,pointer p, pointer q) ;
+
+@ @c
+void mp_move_knot (MP mp,pointer p, pointer q) {
+ mp_link(knil(p))=mp_link(p);
+ knil(mp_link(p))=knil(p);
+ knil(p)=q;
+ mp_link(p)=mp_link(q);
+ mp_link(q)=p;
+ knil(mp_link(p))=p;
+}
+
+@ @<Find any knots on the path from |s| to |l| below the |l|-|r| line...@>=
+p=s;
+while ( p!=l ) {
+ q=mp_link(p);
+ if ( mp_ab_vs_cd(mp, dx,mp_y_coord(p)-mp_y_coord(l),dy,mp_x_coord(p)-mp_x_coord(l))<0 )
+ mp_move_knot(mp, p,l);
+ p=q;
+}
+
+@ The list is likely to be in order already so we just do linear insertions.
+Secondary comparisons on $y$ ensure that the sort is consistent with the
+choice of |l| and |r|.
+
+@<Sort the path from |l| to |r| by increasing $x$@>=
+p=mp_link(l);
+while ( p!=r ) {
+ q=knil(p);
+ while ( mp_x_coord(q)>mp_x_coord(p) ) q=knil(q);
+ while ( mp_x_coord(q)==mp_x_coord(p) ) {
+ if ( mp_y_coord(q)>mp_y_coord(p) ) q=knil(q); else break;
+ }
+ if ( q==knil(p) ) p=mp_link(p);
+ else { p=mp_link(p); mp_move_knot(mp, knil(p),q); };
+}
+
+@ @<Sort the path from |r| to |l| by decreasing $x$@>=
+p=mp_link(r);
+while ( p!=l ){
+ q=knil(p);
+ while ( mp_x_coord(q)<mp_x_coord(p) ) q=knil(q);
+ while ( mp_x_coord(q)==mp_x_coord(p) ) {
+ if ( mp_y_coord(q)<mp_y_coord(p) ) q=knil(q); else break;
+ }
+ if ( q==knil(p) ) p=mp_link(p);
+ else { p=mp_link(p); mp_move_knot(mp, knil(p),q); };
+}
+
+@ The condition involving |ab_vs_cd| tests if there is not a left turn
+at knot |q|. There usually will be a left turn so we streamline the case
+where the |then| clause is not executed.
+
+@<Do a Gramm scan and remove vertices where there...@>=
+{
+p=l; q=mp_link(l);
+while (1) {
+ dx=mp_x_coord(q)-mp_x_coord(p);
+ dy=mp_y_coord(q)-mp_y_coord(p);
+ p=q; q=mp_link(q);
+ if ( p==l ) break;
+ if ( p!=r )
+ if ( mp_ab_vs_cd(mp, dx,mp_y_coord(q)-mp_y_coord(p),dy,mp_x_coord(q)-mp_x_coord(p))<=0 ) {
+ @<Remove knot |p| and back up |p| and |q| but don't go past |l|@>;
+ }
+ }
+}
+
+@ @<Remove knot |p| and back up |p| and |q| but don't go past |l|@>=
+{
+s=knil(p);
+mp_free_node(mp, p,knot_node_size);
+mp_link(s)=q; knil(q)=s;
+if ( s==l ) p=s;
+else { p=knil(s); q=s; };
+}
+
+@ The |find_offset| procedure sets global variables |(cur_x,cur_y)| to the
+offset associated with the given direction |(x,y)|. If two different offsets
+apply, it chooses one of them.
+
+@c
+static void mp_find_offset (MP mp,scaled x, scaled y, pointer h) {
+ pointer p,q; /* consecutive knots */
+ scaled wx,wy,hx,hy;
+ /* the transformation matrix for an elliptical pen */
+ fraction xx,yy; /* untransformed offset for an elliptical pen */
+ fraction d; /* a temporary register */
+ if ( pen_is_elliptical(h) ) {
+ @<Find the offset for |(x,y)| on the elliptical pen~|h|@>
+ } else {
+ q=h;
+ do {
+ p=q; q=mp_link(q);
+ } while (!(mp_ab_vs_cd(mp, mp_x_coord(q)-mp_x_coord(p),y, mp_y_coord(q)-mp_y_coord(p),x)>=0));
+ do {
+ p=q; q=mp_link(q);
+ } while (!(mp_ab_vs_cd(mp, mp_x_coord(q)-mp_x_coord(p),y, mp_y_coord(q)-mp_y_coord(p),x)<=0));
+ mp->cur_x=mp_x_coord(p);
+ mp->cur_y=mp_y_coord(p);
+ }
+}
+
+@ @<Glob...@>=
+scaled cur_x;
+scaled cur_y; /* all-purpose return value registers */
+
+@ @<Find the offset for |(x,y)| on the elliptical pen~|h|@>=
+if ( (x==0) && (y==0) ) {
+ mp->cur_x=mp_x_coord(h); mp->cur_y=mp_y_coord(h);
+} else {
+ @<Find the non-constant part of the transformation for |h|@>;
+ while ( (abs(x)<fraction_half) && (abs(y)<fraction_half) ){
+ x+=x; y+=y;
+ };
+ @<Make |(xx,yy)| the offset on the untransformed \&{pencircle} for the
+ untransformed version of |(x,y)|@>;
+ mp->cur_x=mp_x_coord(h)+mp_take_fraction(mp, xx,wx)+mp_take_fraction(mp, yy,hx);
+ mp->cur_y=mp_y_coord(h)+mp_take_fraction(mp, xx,wy)+mp_take_fraction(mp, yy,hy);
+}
+
+@ @<Find the non-constant part of the transformation for |h|@>=
+wx=mp_left_x(h)-mp_x_coord(h);
+wy=mp_left_y(h)-mp_y_coord(h);
+hx=mp_right_x(h)-mp_x_coord(h);
+hy=mp_right_y(h)-mp_y_coord(h)
+
+@ @<Make |(xx,yy)| the offset on the untransformed \&{pencircle} for the...@>=
+yy=-(mp_take_fraction(mp, x,hy)+mp_take_fraction(mp, y,-hx));
+xx=mp_take_fraction(mp, x,-wy)+mp_take_fraction(mp, y,wx);
+d=mp_pyth_add(mp, xx,yy);
+if ( d>0 ) {
+ xx=half(mp_make_fraction(mp, xx,d));
+ yy=half(mp_make_fraction(mp, yy,d));
+}
+
+@ Finding the bounding box of a pen is easy except if the pen is elliptical.
+But we can handle that case by just calling |find_offset| twice. The answer
+is stored in the global variables |minx|, |maxx|, |miny|, and |maxy|.
+
+@c
+static void mp_pen_bbox (MP mp,pointer h) {
+ pointer p; /* for scanning the knot list */
+ if ( pen_is_elliptical(h) ) {
+ @<Find the bounding box of an elliptical pen@>;
+ } else {
+ mp_minx=mp_x_coord(h); mp_maxx=mp_minx;
+ mp_miny=mp_y_coord(h); mp_maxy=mp_miny;
+ p=mp_link(h);
+ while ( p!=h ) {
+ if ( mp_x_coord(p)<mp_minx ) mp_minx=mp_x_coord(p);
+ if ( mp_y_coord(p)<mp_miny ) mp_miny=mp_y_coord(p);
+ if ( mp_x_coord(p)>mp_maxx ) mp_maxx=mp_x_coord(p);
+ if ( mp_y_coord(p)>mp_maxy ) mp_maxy=mp_y_coord(p);
+ p=mp_link(p);
+ }
+ }
+}
+
+@ @<Find the bounding box of an elliptical pen@>=
+{
+mp_find_offset(mp, 0,fraction_one,h);
+mp_maxx=mp->cur_x;
+mp_minx=2*mp_x_coord(h)-mp->cur_x;
+mp_find_offset(mp, -fraction_one,0,h);
+mp_maxy=mp->cur_y;
+mp_miny=2*mp_y_coord(h)-mp->cur_y;
+}
+
+@* \[21] Edge structures.
+Now we come to \MP's internal scheme for representing pictures.
+The representation is very different from \MF's edge structures
+because \MP\ pictures contain \ps\ graphics objects instead of pixel
+images. However, the basic idea is somewhat similar in that shapes
+are represented via their boundaries.
+
+The main purpose of edge structures is to keep track of graphical objects
+until it is time to translate them into \ps. Since \MP\ does not need to
+know anything about an edge structure other than how to translate it into
+\ps\ and how to find its bounding box, edge structures can be just linked
+lists of graphical objects. \MP\ has no easy way to determine whether
+two such objects overlap, but it suffices to draw the first one first and
+let the second one overwrite it if necessary.
+
+@(mplib.h@>=
+enum mp_graphical_object_code {
+ @<Graphical object codes@>
+ mp_final_graphic
+};
+
+@ Let's consider the types of graphical objects one at a time.
+First of all, a filled contour is represented by a eight-word node. The first
+word contains |type| and |link| fields, and the next six words contain a
+pointer to a cyclic path and the value to use for \ps' \&{currentrgbcolor}
+parameter. If a pen is used for filling |pen_p|, |ljoin_val| and |miterlim_val|
+give the relevant information.
+
+@d mp_path_p(A) mp_link((A)+1)
+ /* a pointer to the path that needs filling */
+@d mp_pen_p(A) mp_info((A)+1)
+ /* a pointer to the pen to fill or stroke with */
+@d mp_color_model(A) mp_type((A)+2) /* the color model */
+@d obj_red_loc(A) ((A)+3) /* the first of three locations for the color */
+@d obj_cyan_loc obj_red_loc /* the first of four locations for the color */
+@d obj_grey_loc obj_red_loc /* the location for the color */
+@d red_val(A) mp->mem[(A)+3].sc
+ /* the red component of the color in the range $0\ldots1$ */
+@d cyan_val red_val
+@d grey_val red_val
+@d green_val(A) mp->mem[(A)+4].sc
+ /* the green component of the color in the range $0\ldots1$ */
+@d magenta_val green_val
+@d blue_val(A) mp->mem[(A)+5].sc
+ /* the blue component of the color in the range $0\ldots1$ */
+@d yellow_val blue_val
+@d black_val(A) mp->mem[(A)+6].sc
+ /* the blue component of the color in the range $0\ldots1$ */
+@d ljoin_val(A) mp_name_type((A)) /* the value of \&{linejoin} */
+@:mp_linejoin_}{\&{linejoin} primitive@>
+@d miterlim_val(A) mp->mem[(A)+7].sc /* the value of \&{miterlimit} */
+@:mp_miterlimit_}{\&{miterlimit} primitive@>
+@d obj_color_part(A) mp->mem[(A)+3-red_part].sc
+ /* interpret an object pointer that has been offset by |red_part..blue_part| */
+@d mp_pre_script(A) mp->mem[(A)+8].hh.lh
+@d mp_post_script(A) mp->mem[(A)+8].hh.rh
+@d fill_node_size 9
+
+@ @<Graphical object codes@>=
+mp_fill_code=1,
+
+@ @c
+static pointer mp_new_fill_node (MP mp,pointer p) {
+ /* make a fill node for cyclic path |p| and color black */
+ pointer t; /* the new node */
+ t=mp_get_node(mp, fill_node_size);
+ mp_type(t)=mp_fill_code;
+ mp_path_p(t)=p;
+ mp_pen_p(t)=null; /* |null| means don't use a pen */
+ red_val(t)=0;
+ green_val(t)=0;
+ blue_val(t)=0;
+ black_val(t)=0;
+ mp_color_model(t)=mp_uninitialized_model;
+ mp_pre_script(t)=null;
+ mp_post_script(t)=null;
+ @<Set the |ljoin_val| and |miterlim_val| fields in object |t|@>;
+ return t;
+}
+
+@ @<Set the |ljoin_val| and |miterlim_val| fields in object |t|@>=
+if ( mp->internal[mp_linejoin]>unity ) ljoin_val(t)=2;
+else if ( mp->internal[mp_linejoin]>0 ) ljoin_val(t)=1;
+else ljoin_val(t)=0;
+if ( mp->internal[mp_miterlimit]<unity )
+ miterlim_val(t)=unity;
+else
+ miterlim_val(t)=mp->internal[mp_miterlimit]
+
+@ A stroked path is represented by an eight-word node that is like a filled
+contour node except that it contains the current \&{linecap} value, a scale
+factor for the dash pattern, and a pointer that is non-null if the stroke
+is to be dashed. The purpose of the scale factor is to allow a picture to
+be transformed without touching the picture that |dash_p| points to.
+
+@d mp_dash_p(A) mp_link((A)+9)
+ /* a pointer to the edge structure that gives the dash pattern */
+@d lcap_val(A) mp_type((A)+9)
+ /* the value of \&{linecap} */
+@:mp_linecap_}{\&{linecap} primitive@>
+@d dash_scale(A) mp->mem[(A)+10].sc /* dash lengths are scaled by this factor */
+@d stroked_node_size 11
+
+@ @<Graphical object codes@>=
+mp_stroked_code=2,
+
+@ @c
+static pointer mp_new_stroked_node (MP mp,pointer p) {
+ /* make a stroked node for path |p| with |mp_pen_p(p)| temporarily |null| */
+ pointer t; /* the new node */
+ t=mp_get_node(mp, stroked_node_size);
+ mp_type(t)=mp_stroked_code;
+ mp_path_p(t)=p; mp_pen_p(t)=null;
+ mp_dash_p(t)=null;
+ dash_scale(t)=unity;
+ red_val(t)=0;
+ green_val(t)=0;
+ blue_val(t)=0;
+ black_val(t)=0;
+ mp_color_model(t)=mp_uninitialized_model;
+ mp_pre_script(t)=null;
+ mp_post_script(t)=null;
+ @<Set the |ljoin_val| and |miterlim_val| fields in object |t|@>;
+ if ( mp->internal[mp_linecap]>unity ) lcap_val(t)=2;
+ else if ( mp->internal[mp_linecap]>0 ) lcap_val(t)=1;
+ else lcap_val(t)=0;
+ return t;
+}
+
+@ When a dashed line is computed in a transformed coordinate system, the dash
+lengths get scaled like the pen shape and we need to compensate for this. Since
+there is no unique scale factor for an arbitrary transformation, we use the
+the square root of the determinant. The properties of the determinant make it
+easier to maintain the |dash_scale|. The computation is fairly straight-forward
+except for the initialization of the scale factor |s|. The factor of 64 is
+needed because |square_rt| scales its result by $2^8$ while we need $2^{14}$
+to counteract the effect of |take_fraction|.
+
+@ @c
+scaled mp_sqrt_det (MP mp,scaled a, scaled b, scaled c, scaled d) {
+ scaled maxabs; /* $max(|a|,|b|,|c|,|d|)$ */
+ unsigned s; /* amount by which the result of |square_rt| needs to be scaled */
+ @<Initialize |maxabs|@>;
+ s=64;
+ while ( (maxabs<fraction_one) && (s>1) ){
+ a+=a; b+=b; c+=c; d+=d;
+ maxabs+=maxabs; s=(unsigned)(halfp(s));
+ }
+ return (scaled)(s*mp_square_rt(mp, abs(mp_take_fraction(mp, a,d)-mp_take_fraction(mp, b,c))));
+}
+@#
+static scaled mp_get_pen_scale (MP mp,pointer p) {
+ return mp_sqrt_det(mp,
+ mp_left_x(p)-mp_x_coord(p), mp_right_x(p)-mp_x_coord(p),
+ mp_left_y(p)-mp_y_coord(p), mp_right_y(p)-mp_y_coord(p));
+}
+
+@ @<Declarations@>=
+static scaled mp_sqrt_det (MP mp,scaled a, scaled b, scaled c, scaled d) ;
+
+
+@ @<Initialize |maxabs|@>=
+maxabs=abs(a);
+if ( abs(b)>maxabs ) maxabs=abs(b);
+if ( abs(c)>maxabs ) maxabs=abs(c);
+if ( abs(d)>maxabs ) maxabs=abs(d)
+
+@ When a picture contains text, this is represented by a fourteen-word node
+where the color information and |type| and |link| fields are augmented by
+additional fields that describe the text and how it is transformed.
+The |path_p| and |mp_pen_p| pointers are replaced by a number that identifies
+the font and a string number that gives the text to be displayed.
+The |width|, |height|, and |depth| fields
+give the dimensions of the text at its design size, and the remaining six
+words give a transformation to be applied to the text. The |new_text_node|
+function initializes everything to default values so that the text comes out
+black with its reference point at the origin.
+
+@d mp_text_p(A) mp_link((A)+1) /* a string pointer for the text to display */
+@d mp_font_n(A) mp_info((A)+1) /* the font number */
+@d width_val(A) mp->mem[(A)+7].sc /* unscaled width of the text */
+@d height_val(A) mp->mem[(A)+9].sc /* unscaled height of the text */
+@d depth_val(A) mp->mem[(A)+10].sc /* unscaled depth of the text */
+@d text_tx_loc(A) ((A)+11)
+ /* the first of six locations for transformation parameters */
+@d tx_val(A) mp->mem[(A)+11].sc /* $x$ shift amount */
+@d ty_val(A) mp->mem[(A)+12].sc /* $y$ shift amount */
+@d txx_val(A) mp->mem[(A)+13].sc /* |txx| transformation parameter */
+@d txy_val(A) mp->mem[(A)+14].sc /* |txy| transformation parameter */
+@d tyx_val(A) mp->mem[(A)+15].sc /* |tyx| transformation parameter */
+@d tyy_val(A) mp->mem[(A)+16].sc /* |tyy| transformation parameter */
+@d text_trans_part(A) mp->mem[(A)+11-x_part].sc
+ /* interpret a text node pointer that has been offset by |x_part..yy_part| */
+@d text_node_size 17
+
+@ @<Graphical object codes@>=
+mp_text_code=3,
+
+@ @c
+static pointer mp_new_text_node (MP mp,char *f,str_number s) {
+ /* make a text node for font |f| and text string |s| */
+ pointer t; /* the new node */
+ t=mp_get_node(mp, text_node_size);
+ mp_type(t)=mp_text_code;
+ mp_text_p(t)=s;
+ mp_font_n(t)=(halfword)mp_find_font(mp, f); /* this identifies the font */
+ red_val(t)=0;
+ green_val(t)=0;
+ blue_val(t)=0;
+ black_val(t)=0;
+ mp_color_model(t)=mp_uninitialized_model;
+ mp_pre_script(t)=null;
+ mp_post_script(t)=null;
+ tx_val(t)=0; ty_val(t)=0;
+ txx_val(t)=unity; txy_val(t)=0;
+ tyx_val(t)=0; tyy_val(t)=unity;
+ mp_set_text_box(mp, t); /* this finds the bounding box */
+ return t;
+}
+
+@ The last two types of graphical objects that can occur in an edge structure
+are clipping paths and \&{setbounds} paths. These are slightly more difficult
+@:set_bounds_}{\&{setbounds} primitive@>
+to implement because we must keep track of exactly what is being clipped or
+bounded when pictures get merged together. For this reason, each clipping or
+\&{setbounds} operation is represented by a pair of nodes: first comes a
+two-word node whose |path_p| gives the relevant path, then there is the list
+of objects to clip or bound followed by a two-word node whose second word is
+unused.
+
+Using at least two words for each graphical object node allows them all to be
+allocated and deallocated similarly with a global array |gr_object_size| to
+give the size in words for each object type.
+
+@d start_clip_size 2
+@d start_bounds_size 2
+@d stop_clip_size 2 /* the second word is not used here */
+@d stop_bounds_size 2 /* the second word is not used here */
+@#
+@d stop_type(A) ((A)+2)
+ /* matching |type| for |start_clip_code| or |start_bounds_code| */
+@d has_color(A) (mp_type((A))<mp_start_clip_code)
+ /* does a graphical object have color fields? */
+@d has_pen(A) (mp_type((A))<mp_text_code)
+ /* does a graphical object have a |mp_pen_p| field? */
+@d is_start_or_stop(A) (mp_type((A))>=mp_start_clip_code)
+@d is_stop(A) (mp_type((A))>=mp_stop_clip_code)
+
+@ @<Graphical object codes@>=
+mp_start_clip_code=4, /* |type| of a node that starts clipping */
+mp_start_bounds_code=5, /* |type| of a node that gives a \&{setbounds} path */
+mp_stop_clip_code=6, /* |type| of a node that stops clipping */
+mp_stop_bounds_code=7, /* |type| of a node that stops \&{setbounds} */
+
+@ @c
+static pointer mp_new_bounds_node (MP mp,pointer p, quarterword c) {
+ /* make a node of type |c| where |p| is the clipping or \&{setbounds} path */
+ pointer t; /* the new node */
+ t=mp_get_node(mp, mp->gr_object_size[c]);
+ mp_type(t)=c;
+ mp_path_p(t)=p;
+ return t;
+}
+
+@ We need an array to keep track of the sizes of graphical objects.
+
+@<Glob...@>=
+quarterword gr_object_size[mp_stop_bounds_code+1];
+
+@ @<Set init...@>=
+mp->gr_object_size[mp_fill_code]=fill_node_size;
+mp->gr_object_size[mp_stroked_code]=stroked_node_size;
+mp->gr_object_size[mp_text_code]=text_node_size;
+mp->gr_object_size[mp_start_clip_code]=start_clip_size;
+mp->gr_object_size[mp_stop_clip_code]=stop_clip_size;
+mp->gr_object_size[mp_start_bounds_code]=start_bounds_size;
+mp->gr_object_size[mp_stop_bounds_code]=stop_bounds_size;
+
+@ All the essential information in an edge structure is encoded as a linked list
+of graphical objects as we have just seen, but it is helpful to add some
+redundant information. A single edge structure might be used as a dash pattern
+many times, and it would be nice to avoid scanning the same structure
+repeatedly. Thus, an edge structure known to be a suitable dash pattern
+has a header that gives a list of dashes in a sorted order designed for rapid
+translation into \ps.
+
+Each dash is represented by a three-word node containing the initial and final
+$x$~coordinates as well as the usual |link| field. The |link| fields points to
+the dash node with the next higher $x$-coordinates and the final link points
+to a special location called |null_dash|. (There should be no overlap between
+dashes). Since the $y$~coordinate of the dash pattern is needed to determine
+the period of repetition, this needs to be stored in the edge header along
+with a pointer to the list of dash nodes.
+
+@d start_x(A) mp->mem[(A)+1].sc /* the starting $x$~coordinate in a dash node */
+@d stop_x(A) mp->mem[(A)+2].sc /* the ending $x$~coordinate in a dash node */
+@d dash_node_size 3
+@d dash_list mp_link
+ /* in an edge header this points to the first dash node */
+@d dash_y(A) mp->mem[(A)+1].sc /* $y$ value for the dash list in an edge header */
+
+@ It is also convenient for an edge header to contain the bounding
+box information needed by the \&{llcorner} and \&{urcorner} operators
+so that this does not have to be recomputed unnecessarily. This is done by
+adding fields for the $x$~and $y$ extremes as well as a pointer that indicates
+how far the bounding box computation has gotten. Thus if the user asks for
+the bounding box and then adds some more text to the picture before asking
+for more bounding box information, the second computation need only look at
+the additional text.
+
+When the bounding box has not been computed, the |bblast| pointer points
+to a dummy link at the head of the graphical object list while the |minx_val|
+and |miny_val| fields contain |el_gordo| and the |maxx_val| and |maxy_val|
+fields contain |-el_gordo|.
+
+Since the bounding box of pictures containing objects of type
+|mp_start_bounds_code| depends on the value of \&{truecorners}, the bounding box
+@:mp_true_corners_}{\&{truecorners} primitive@>
+data might not be valid for all values of this parameter. Hence, the |bbtype|
+field is needed to keep track of this.
+
+@d minx_val(A) mp->mem[(A)+2].sc
+@d miny_val(A) mp->mem[(A)+3].sc
+@d maxx_val(A) mp->mem[(A)+4].sc
+@d maxy_val(A) mp->mem[(A)+5].sc
+@d bblast(A) mp_link((A)+6) /* last item considered in bounding box computation */
+@d bbtype(A) mp_info((A)+6) /* tells how bounding box data depends on \&{truecorners} */
+@d dummy_loc(A) ((A)+7) /* where the object list begins in an edge header */
+@d no_bounds 0
+ /* |bbtype| value when bounding box data is valid for all \&{truecorners} values */
+@d bounds_set 1
+ /* |bbtype| value when bounding box data is for \&{truecorners}${}\le 0$ */
+@d bounds_unset 2
+ /* |bbtype| value when bounding box data is for \&{truecorners}${}>0$ */
+
+@c
+static void mp_init_bbox (MP mp,pointer h) {
+ /* Initialize the bounding box information in edge structure |h| */
+ bblast(h)=dummy_loc(h);
+ bbtype(h)=no_bounds;
+ minx_val(h)=el_gordo;
+ miny_val(h)=el_gordo;
+ maxx_val(h)=-el_gordo;
+ maxy_val(h)=-el_gordo;
+}
+
+@ The only other entries in an edge header are a reference count in the first
+word and a pointer to the tail of the object list in the last word.
+
+@d obj_tail(A) mp_info((A)+7) /* points to the last entry in the object list */
+@d edge_header_size 8
+
+@c
+static void mp_init_edges (MP mp,pointer h) {
+ /* initialize an edge header to null values */
+ dash_list(h)=null_dash;
+ obj_tail(h)=dummy_loc(h);
+ mp_link(dummy_loc(h))=null;
+ ref_count(h)=null;
+ mp_init_bbox(mp, h);
+}
+
+@ Here is how edge structures are deleted. The process can be recursive because
+of the need to dereference edge structures that are used as dash patterns.
+@^recursion@>
+
+@d add_edge_ref(A) incr(ref_count(A))
+@d delete_edge_ref(A) {
+ if ( ref_count((A))==null )
+ mp_toss_edges(mp, A);
+ else
+ decr(ref_count(A));
+ }
+
+@<Declarations@>=
+static void mp_flush_dash_list (MP mp,pointer h);
+static pointer mp_toss_gr_object (MP mp,pointer p) ;
+static void mp_toss_edges (MP mp,pointer h) ;
+
+@ @c void mp_toss_edges (MP mp,pointer h) {
+ pointer p,q; /* pointers that scan the list being recycled */
+ pointer r; /* an edge structure that object |p| refers to */
+ mp_flush_dash_list(mp, h);
+ q=mp_link(dummy_loc(h));
+ while ( (q!=null) ) {
+ p=q; q=mp_link(q);
+ r=mp_toss_gr_object(mp, p);
+ if ( r!=null ) delete_edge_ref(r);
+ }
+ mp_free_node(mp, h,edge_header_size);
+}
+void mp_flush_dash_list (MP mp,pointer h) {
+ pointer p,q; /* pointers that scan the list being recycled */
+ q=dash_list(h);
+ while ( q!=null_dash ) {
+ p=q; q=mp_link(q);
+ mp_free_node(mp, p,dash_node_size);
+ }
+ dash_list(h)=null_dash;
+}
+pointer mp_toss_gr_object (MP mp,pointer p) {
+ /* returns an edge structure that needs to be dereferenced */
+ pointer e; /* the edge structure to return */
+ e=null;
+ @<Prepare to recycle graphical object |p|@>;
+ mp_free_node(mp, p,mp->gr_object_size[mp_type(p)]);
+ return e;
+}
+
+@ @<Prepare to recycle graphical object |p|@>=
+switch (mp_type(p)) {
+case mp_fill_code:
+ mp_toss_knot_list(mp, mp_path_p(p));
+ if ( mp_pen_p(p)!=null ) mp_toss_knot_list(mp, mp_pen_p(p));
+ if ( mp_pre_script(p)!=null ) delete_str_ref(mp_pre_script(p));
+ if ( mp_post_script(p)!=null ) delete_str_ref(mp_post_script(p));
+ break;
+case mp_stroked_code:
+ mp_toss_knot_list(mp, mp_path_p(p));
+ if ( mp_pen_p(p)!=null ) mp_toss_knot_list(mp, mp_pen_p(p));
+ if ( mp_pre_script(p)!=null ) delete_str_ref(mp_pre_script(p));
+ if ( mp_post_script(p)!=null ) delete_str_ref(mp_post_script(p));
+ e=mp_dash_p(p);
+ break;
+case mp_text_code:
+ delete_str_ref(mp_text_p(p));
+ if ( mp_pre_script(p)!=null ) delete_str_ref(mp_pre_script(p));
+ if ( mp_post_script(p)!=null ) delete_str_ref(mp_post_script(p));
+ break;
+case mp_start_clip_code:
+case mp_start_bounds_code:
+ mp_toss_knot_list(mp, mp_path_p(p));
+ break;
+case mp_stop_clip_code:
+case mp_stop_bounds_code:
+ break;
+} /* there are no other cases */
+
+@ If we use |add_edge_ref| to ``copy'' edge structures, the real copying needs
+to be done before making a significant change to an edge structure. Much of
+the work is done in a separate routine |copy_objects| that copies a list of
+graphical objects into a new edge header.
+
+@c
+static pointer mp_private_edges (MP mp,pointer h) {
+ /* make a private copy of the edge structure headed by |h| */
+ pointer hh; /* the edge header for the new copy */
+ pointer p,pp; /* pointers for copying the dash list */
+ if ( ref_count(h)==null ) {
+ return h;
+ } else {
+ decr(ref_count(h));
+ hh=mp_copy_objects(mp, mp_link(dummy_loc(h)),null);
+ @<Copy the dash list from |h| to |hh|@>;
+ @<Copy the bounding box information from |h| to |hh| and make |bblast(hh)|
+ point into the new object list@>;
+ return hh;
+ }
+}
+
+@ Here we use the fact that |dash_list(hh)=mp_link(hh)|.
+@^data structure assumptions@>
+
+@<Copy the dash list from |h| to |hh|@>=
+pp=hh; p=dash_list(h);
+while ( (p!=null_dash) ) {
+ mp_link(pp)=mp_get_node(mp, dash_node_size);
+ pp=mp_link(pp);
+ start_x(pp)=start_x(p);
+ stop_x(pp)=stop_x(p);
+ p=mp_link(p);
+}
+mp_link(pp)=null_dash;
+dash_y(hh)=dash_y(h)
+
+
+@ |h| is an edge structure
+
+@c
+static mp_dash_object *mp_export_dashes (MP mp, pointer q, scaled *w) {
+ mp_dash_object *d;
+ pointer p, h;
+ scaled scf; /* scale factor */
+ int *dashes = NULL;
+ int num_dashes = 1;
+ h = mp_dash_p(q);
+ if (h==null || dash_list(h)==null_dash)
+ return NULL;
+ p = dash_list(h);
+ scf=mp_get_pen_scale(mp, mp_pen_p(q));
+ if (scf==0) {
+ if (*w==0) scf = dash_scale(q); else return NULL;
+ } else {
+ scf=mp_make_scaled(mp, *w,scf);
+ scf=mp_take_scaled(mp, scf,dash_scale(q));
+ }
+ *w = scf;
+ d = xmalloc(1,sizeof(mp_dash_object));
+ start_x(null_dash)=start_x(p)+dash_y(h);
+ while (p != null_dash) {
+ dashes = xrealloc(dashes, (num_dashes+2), sizeof(scaled));
+ dashes[(num_dashes-1)] =
+ mp_take_scaled(mp,(stop_x(p)-start_x(p)),scf);
+ dashes[(num_dashes)] =
+ mp_take_scaled(mp,(start_x(mp_link(p))-stop_x(p)),scf);
+ dashes[(num_dashes+1)] = -1; /* terminus */
+ num_dashes+=2;
+ p=mp_link(p);
+ }
+ d->array = dashes;
+ d->offset = mp_take_scaled(mp,mp_dash_offset(mp, h),scf);
+ return d;
+}
+
+
+
+@ @<Copy the bounding box information from |h| to |hh|...@>=
+minx_val(hh)=minx_val(h);
+miny_val(hh)=miny_val(h);
+maxx_val(hh)=maxx_val(h);
+maxy_val(hh)=maxy_val(h);
+bbtype(hh)=bbtype(h);
+p=dummy_loc(h); pp=dummy_loc(hh);
+while ((p!=bblast(h)) ) {
+ if ( p==null ) mp_confusion(mp, "bblast");
+@:this can't happen bblast}{\quad bblast@>
+ p=mp_link(p); pp=mp_link(pp);
+}
+bblast(hh)=pp
+
+@ Here is the promised routine for copying graphical objects into a new edge
+structure. It starts copying at object~|p| and stops just before object~|q|.
+If |q| is null, it copies the entire sublist headed at |p|. The resulting edge
+structure requires further initialization by |init_bbox|.
+
+@<Declarations@>=
+static pointer mp_copy_objects (MP mp, pointer p, pointer q);
+
+@ @c
+pointer mp_copy_objects (MP mp, pointer p, pointer q) {
+ pointer hh; /* the new edge header */
+ pointer pp; /* the last newly copied object */
+ quarterword k; /* temporary register */
+ hh=mp_get_node(mp, edge_header_size);
+ dash_list(hh)=null_dash;
+ ref_count(hh)=null;
+ pp=dummy_loc(hh);
+ while ( (p!=q) ) {
+ @<Make |mp_link(pp)| point to a copy of object |p|, and update |p| and |pp|@>;
+ }
+ obj_tail(hh)=pp;
+ mp_link(pp)=null;
+ return hh;
+}
+
+@ @<Make |mp_link(pp)| point to a copy of object |p|, and update |p| and |pp|@>=
+{ k=mp->gr_object_size[mp_type(p)];
+ mp_link(pp)=mp_get_node(mp, k);
+ pp=mp_link(pp);
+ while ( (k>0) ) { decr(k); mp->mem[pp+k]=mp->mem[p+k]; };
+ @<Fix anything in graphical object |pp| that should differ from the
+ corresponding field in |p|@>;
+ p=mp_link(p);
+}
+
+@ @<Fix anything in graphical object |pp| that should differ from the...@>=
+switch (mp_type(p)) {
+case mp_start_clip_code:
+case mp_start_bounds_code:
+ mp_path_p(pp)=mp_copy_path(mp, mp_path_p(p));
+ break;
+case mp_fill_code:
+ mp_path_p(pp)=mp_copy_path(mp, mp_path_p(p));
+ if ( mp_pre_script(p)!=null ) add_str_ref(mp_pre_script(p));
+ if ( mp_post_script(p)!=null ) add_str_ref(mp_post_script(p));
+ if ( mp_pen_p(p)!=null ) mp_pen_p(pp)=copy_pen(mp_pen_p(p));
+ break;
+case mp_stroked_code:
+ if ( mp_pre_script(p)!=null ) add_str_ref(mp_pre_script(p));
+ if ( mp_post_script(p)!=null ) add_str_ref(mp_post_script(p));
+ mp_path_p(pp)=mp_copy_path(mp, mp_path_p(p));
+ mp_pen_p(pp)=copy_pen(mp_pen_p(p));
+ if ( mp_dash_p(p)!=null ) add_edge_ref(mp_dash_p(pp));
+ break;
+case mp_text_code:
+ if ( mp_pre_script(p)!=null ) add_str_ref(mp_pre_script(p));
+ if ( mp_post_script(p)!=null ) add_str_ref(mp_post_script(p));
+ add_str_ref(mp_text_p(pp));
+ break;
+case mp_stop_clip_code:
+case mp_stop_bounds_code:
+ break;
+} /* there are no other cases */
+
+@ Here is one way to find an acceptable value for the second argument to
+|copy_objects|. Given a non-null graphical object list, |skip_1component|
+skips past one picture component, where a ``picture component'' is a single
+graphical object, or a start bounds or start clip object and everything up
+through the matching stop bounds or stop clip object. The macro version avoids
+procedure call overhead and error handling: |skip_component(p)(e)| advances |p|
+unless |p| points to a stop bounds or stop clip node, in which case it executes
+|e| instead.
+
+@d skip_component(A)
+ if ( ! is_start_or_stop((A)) ) (A)=mp_link((A));
+ else if ( ! is_stop((A)) ) (A)=mp_skip_1component(mp, (A));
+ else
+
+@c
+static pointer mp_skip_1component (MP mp,pointer p) {
+ integer lev; /* current nesting level */
+ lev=0;
+ do {
+ if ( is_start_or_stop(p) ) {
+ if ( is_stop(p) ) decr(lev); else incr(lev);
+ }
+ p=mp_link(p);
+ } while (lev!=0);
+ return p;
+}
+
+@ Here is a diagnostic routine for printing an edge structure in symbolic form.
+
+@<Declarations@>=
+static void mp_print_edges (MP mp,pointer h, const char *s, boolean nuline) ;
+
+@ @c
+void mp_print_edges (MP mp,pointer h, const char *s, boolean nuline) {
+ pointer p; /* a graphical object to be printed */
+ pointer hh,pp; /* temporary pointers */
+ scaled scf; /* a scale factor for the dash pattern */
+ boolean ok_to_dash; /* |false| for polygonal pen strokes */
+ mp_print_diagnostic(mp, "Edge structure",s,nuline);
+ p=dummy_loc(h);
+ while ( mp_link(p)!=null ) {
+ p=mp_link(p);
+ mp_print_ln(mp);
+ switch (mp_type(p)) {
+ @<Cases for printing graphical object node |p|@>;
+ default:
+ mp_print(mp, "[unknown object type!]");
+ break;
+ }
+ }
+ mp_print_nl(mp, "End edges");
+ if ( p!=obj_tail(h) ) mp_print(mp, "?");
+@.End edges?@>
+ mp_end_diagnostic(mp, true);
+}
+
+@ @<Cases for printing graphical object node |p|@>=
+case mp_fill_code:
+ mp_print(mp, "Filled contour ");
+ mp_print_obj_color(mp, p);
+ mp_print_char(mp, xord(':')); mp_print_ln(mp);
+ mp_pr_path(mp, mp_path_p(p)); mp_print_ln(mp);
+ if ( (mp_pen_p(p)!=null) ) {
+ @<Print join type for graphical object |p|@>;
+ mp_print(mp, " with pen"); mp_print_ln(mp);
+ mp_pr_pen(mp, mp_pen_p(p));
+ }
+ break;
+
+@ @<Print join type for graphical object |p|@>=
+switch (ljoin_val(p)) {
+case 0:
+ mp_print(mp, "mitered joins limited ");
+ mp_print_scaled(mp, miterlim_val(p));
+ break;
+case 1:
+ mp_print(mp, "round joins");
+ break;
+case 2:
+ mp_print(mp, "beveled joins");
+ break;
+default:
+ mp_print(mp, "?? joins");
+@.??@>
+ break;
+}
+
+@ For stroked nodes, we need to print |lcap_val(p)| as well.
+
+@<Print join and cap types for stroked node |p|@>=
+switch (lcap_val(p)) {
+case 0:mp_print(mp, "butt"); break;
+case 1:mp_print(mp, "round"); break;
+case 2:mp_print(mp, "square"); break;
+default: mp_print(mp, "??"); break;
+@.??@>
+}
+mp_print(mp, " ends, ");
+@<Print join type for graphical object |p|@>
+
+@ Here is a routine that prints the color of a graphical object if it isn't
+black (the default color).
+
+@<Declarations@>=
+static void mp_print_obj_color (MP mp,pointer p) ;
+
+@ @c
+void mp_print_obj_color (MP mp,pointer p) {
+ if ( mp_color_model(p)==mp_grey_model ) {
+ if ( grey_val(p)>0 ) {
+ mp_print(mp, "greyed ");
+ mp_print_compact_node(mp, obj_grey_loc(p),1);
+ };
+ } else if ( mp_color_model(p)==mp_cmyk_model ) {
+ if ( (cyan_val(p)>0) || (magenta_val(p)>0) ||
+ (yellow_val(p)>0) || (black_val(p)>0) ) {
+ mp_print(mp, "processcolored ");
+ mp_print_compact_node(mp, obj_cyan_loc(p),4);
+ };
+ } else if ( mp_color_model(p)==mp_rgb_model ) {
+ if ( (red_val(p)>0) || (green_val(p)>0) || (blue_val(p)>0) ) {
+ mp_print(mp, "colored ");
+ mp_print_compact_node(mp, obj_red_loc(p),3);
+ };
+ }
+}
+
+@ We also need a procedure for printing consecutive scaled values as if they
+were a known big node.
+
+@<Declarations@>=
+static void mp_print_compact_node (MP mp,pointer p, quarterword k) ;
+
+@ @c
+void mp_print_compact_node (MP mp,pointer p, quarterword k) {
+ pointer q; /* last location to print */
+ q=p+k-1;
+ mp_print_char(mp, xord('('));
+ while ( p<=q ){
+ mp_print_scaled(mp, mp->mem[p].sc);
+ if ( p<q ) mp_print_char(mp, xord(','));
+ incr(p);
+ }
+ mp_print_char(mp, xord(')'));
+}
+
+@ @<Cases for printing graphical object node |p|@>=
+case mp_stroked_code:
+ mp_print(mp, "Filled pen stroke ");
+ mp_print_obj_color(mp, p);
+ mp_print_char(mp, xord(':')); mp_print_ln(mp);
+ mp_pr_path(mp, mp_path_p(p));
+ if ( mp_dash_p(p)!=null ) {
+ mp_print_nl(mp, "dashed (");
+ @<Finish printing the dash pattern that |p| refers to@>;
+ }
+ mp_print_ln(mp);
+ @<Print join and cap types for stroked node |p|@>;
+ mp_print(mp, " with pen"); mp_print_ln(mp);
+ if ( mp_pen_p(p)==null ) mp_print(mp, "???"); /* shouldn't happen */
+@.???@>
+ else mp_pr_pen(mp, mp_pen_p(p));
+ break;
+
+@ Normally, the |dash_list| field in an edge header is set to |null_dash|
+when it is not known to define a suitable dash pattern. This is disallowed
+here because the |mp_dash_p| field should never point to such an edge header.
+Note that memory is allocated for |start_x(null_dash)| and we are free to
+give it any convenient value.
+
+@<Finish printing the dash pattern that |p| refers to@>=
+ok_to_dash=pen_is_elliptical(mp_pen_p(p));
+if ( ! ok_to_dash ) scf=unity; else scf=dash_scale(p);
+hh=mp_dash_p(p);
+pp=dash_list(hh);
+if ( (pp==null_dash) || (dash_y(hh)<0) ) {
+ mp_print(mp, " ??");
+} else { start_x(null_dash)=start_x(pp)+dash_y(hh);
+ while ( pp!=null_dash ) {
+ mp_print(mp, "on ");
+ mp_print_scaled(mp, mp_take_scaled(mp, stop_x(pp)-start_x(pp),scf));
+ mp_print(mp, " off ");
+ mp_print_scaled(mp, mp_take_scaled(mp, start_x(mp_link(pp))-stop_x(pp),scf));
+ pp = mp_link(pp);
+ if ( pp!=null_dash ) mp_print_char(mp, xord(' '));
+ }
+ mp_print(mp, ") shifted ");
+ mp_print_scaled(mp, -mp_take_scaled(mp, mp_dash_offset(mp, hh),scf));
+ if ( ! ok_to_dash || (dash_y(hh)==0) ) mp_print(mp, " (this will be ignored)");
+}
+
+@ @<Declarations@>=
+static scaled mp_dash_offset (MP mp,pointer h) ;
+
+@ @c
+scaled mp_dash_offset (MP mp,pointer h) {
+ scaled x; /* the answer */
+ if (dash_list(h)==null_dash || dash_y(h)<0) mp_confusion(mp, "dash0");
+@:this can't happen dash0}{\quad dash0@>
+ if ( dash_y(h)==0 ) {
+ x=0;
+ } else {
+ x=-(start_x(dash_list(h)) % dash_y(h));
+ if ( x<0 ) x=x+dash_y(h);
+ }
+ return x;
+}
+
+@ @<Cases for printing graphical object node |p|@>=
+case mp_text_code:
+ mp_print_char(mp, xord('"')); mp_print_str(mp,mp_text_p(p));
+ mp_print(mp, "\" infont \""); mp_print(mp, mp->font_name[mp_font_n(p)]);
+ mp_print_char(mp, xord('"')); mp_print_ln(mp);
+ mp_print_obj_color(mp, p);
+ mp_print(mp, "transformed ");
+ mp_print_compact_node(mp, text_tx_loc(p),6);
+ break;
+
+@ @<Cases for printing graphical object node |p|@>=
+case mp_start_clip_code:
+ mp_print(mp, "clipping path:");
+ mp_print_ln(mp);
+ mp_pr_path(mp, mp_path_p(p));
+ break;
+case mp_stop_clip_code:
+ mp_print(mp, "stop clipping");
+ break;
+
+@ @<Cases for printing graphical object node |p|@>=
+case mp_start_bounds_code:
+ mp_print(mp, "setbounds path:");
+ mp_print_ln(mp);
+ mp_pr_path(mp, mp_path_p(p));
+ break;
+case mp_stop_bounds_code:
+ mp_print(mp, "end of setbounds");
+ break;
+
+@ To initialize the |dash_list| field in an edge header~|h|, we need a
+subroutine that scans an edge structure and tries to interpret it as a dash
+pattern. This can only be done when there are no filled regions or clipping
+paths and all the pen strokes have the same color. The first step is to let
+$y_0$ be the initial $y$~coordinate of the first pen stroke. Then we implicitly
+project all the pen stroke paths onto the line $y=y_0$ and require that there
+be no retracing. If the resulting paths cover a range of $x$~coordinates of
+length $\Delta x$, we set |dash_y(h)| to the length of the dash pattern by
+finding the maximum of $\Delta x$ and the absolute value of~$y_0$.
+
+@c
+static pointer mp_make_dashes (MP mp,pointer h) { /* returns |h| or |null| */
+ pointer p; /* this scans the stroked nodes in the object list */
+ pointer p0; /* if not |null| this points to the first stroked node */
+ pointer pp,qq,rr; /* pointers into |mp_path_p(p)| */
+ pointer d,dd; /* pointers used to create the dash list */
+ scaled y0;
+ @<Other local variables in |make_dashes|@>;
+ y0=0; /* the initial $y$ coordinate */
+ if ( dash_list(h)!=null_dash )
+ return h;
+ p0=null;
+ p=mp_link(dummy_loc(h));
+ while ( p!=null ) {
+ if ( mp_type(p)!=mp_stroked_code ) {
+ @<Compain that the edge structure contains a node of the wrong type
+ and |goto not_found|@>;
+ }
+ pp=mp_path_p(p);
+ if ( p0==null ){ p0=p; y0=mp_y_coord(pp); };
+ @<Make |d| point to a new dash node created from stroke |p| and path |pp|
+ or |goto not_found| if there is an error@>;
+ @<Insert |d| into the dash list and |goto not_found| if there is an error@>;
+ p=mp_link(p);
+ }
+ if ( dash_list(h)==null_dash )
+ goto NOT_FOUND; /* No error message */
+ @<Scan |dash_list(h)| and deal with any dashes that are themselves dashed@>;
+ @<Set |dash_y(h)| and merge the first and last dashes if necessary@>;
+ return h;
+NOT_FOUND:
+ @<Flush the dash list, recycle |h| and return |null|@>;
+}
+
+@ @<Compain that the edge structure contains a node of the wrong type...@>=
+{
+print_err("Picture is too complicated to use as a dash pattern");
+help3("When you say `dashed p', picture p should not contain any",
+ "text, filled regions, or clipping paths. This time it did",
+ "so I'll just make it a solid line instead.");
+mp_put_get_error(mp);
+goto NOT_FOUND;
+}
+
+@ A similar error occurs when monotonicity fails.
+
+@<Declarations@>=
+static void mp_x_retrace_error (MP mp) ;
+
+@ @c
+void mp_x_retrace_error (MP mp) {
+print_err("Picture is too complicated to use as a dash pattern");
+help3("When you say `dashed p', every path in p should be monotone",
+ "in x and there must be no overlapping. This failed",
+ "so I'll just make it a solid line instead.");
+mp_put_get_error(mp);
+}
+
+@ We stash |p| in |mp_info(d)| if |mp_dash_p(p)<>0| so that subsequent processing can
+handle the case where the pen stroke |p| is itself dashed.
+
+@<Make |d| point to a new dash node created from stroke |p| and path...@>=
+@<Make sure |p| and |p0| are the same color and |goto not_found| if there is
+ an error@>;
+rr=pp;
+if ( mp_link(pp)!=pp ) {
+ do {
+ qq=rr; rr=mp_link(rr);
+ @<Check for retracing between knots |qq| and |rr| and |goto not_found|
+ if there is a problem@>;
+ } while (mp_right_type(rr)!=mp_endpoint);
+}
+d=mp_get_node(mp, dash_node_size);
+if ( mp_dash_p(p)==0 ) mp_info(d)=0; else mp_info(d)=p;
+if ( mp_x_coord(pp)<mp_x_coord(rr) ) {
+ start_x(d)=mp_x_coord(pp);
+ stop_x(d)=mp_x_coord(rr);
+} else {
+ start_x(d)=mp_x_coord(rr);
+ stop_x(d)=mp_x_coord(pp);
+}
+
+@ We also need to check for the case where the segment from |qq| to |rr| is
+monotone in $x$ but is reversed relative to the path from |pp| to |qq|.
+
+@<Check for retracing between knots |qq| and |rr| and |goto not_found|...@>=
+x0=mp_x_coord(qq);
+x1=mp_right_x(qq);
+x2=mp_left_x(rr);
+x3=mp_x_coord(rr);
+if ( (x0>x1) || (x1>x2) || (x2>x3) ) {
+ if ( (x0<x1) || (x1<x2) || (x2<x3) ) {
+ if ( mp_ab_vs_cd(mp, x2-x1,x2-x1,x1-x0,x3-x2)>0 ) {
+ mp_x_retrace_error(mp); goto NOT_FOUND;
+ }
+ }
+}
+if ( (mp_x_coord(pp)>x0) || (x0>x3) ) {
+ if ( (mp_x_coord(pp)<x0) || (x0<x3) ) {
+ mp_x_retrace_error(mp); goto NOT_FOUND;
+ }
+}
+
+@ @<Other local variables in |make_dashes|@>=
+ scaled x0,x1,x2,x3; /* $x$ coordinates of the segment from |qq| to |rr| */
+
+@ @<Make sure |p| and |p0| are the same color and |goto not_found|...@>=
+if ( (red_val(p)!=red_val(p0)) || (black_val(p)!=black_val(p0)) ||
+ (green_val(p)!=green_val(p0)) || (blue_val(p)!=blue_val(p0)) ) {
+ print_err("Picture is too complicated to use as a dash pattern");
+ help3("When you say `dashed p', everything in picture p should",
+ "be the same color. I can\'t handle your color changes",
+ "so I'll just make it a solid line instead.");
+ mp_put_get_error(mp);
+ goto NOT_FOUND;
+}
+
+@ @<Insert |d| into the dash list and |goto not_found| if there is an error@>=
+start_x(null_dash)=stop_x(d);
+dd=h; /* this makes |mp_link(dd)=dash_list(h)| */
+while ( start_x(mp_link(dd))<stop_x(d) )
+ dd=mp_link(dd);
+if ( dd!=h ) {
+ if ( (stop_x(dd)>start_x(d)) )
+ { mp_x_retrace_error(mp); goto NOT_FOUND; };
+}
+mp_link(d)=mp_link(dd);
+mp_link(dd)=d
+
+@ @<Set |dash_y(h)| and merge the first and last dashes if necessary@>=
+d=dash_list(h);
+while ( (mp_link(d)!=null_dash) )
+ d=mp_link(d);
+dd=dash_list(h);
+dash_y(h)=stop_x(d)-start_x(dd);
+if ( abs(y0)>dash_y(h) ) {
+ dash_y(h)=abs(y0);
+} else if ( d!=dd ) {
+ dash_list(h)=mp_link(dd);
+ stop_x(d)=stop_x(dd)+dash_y(h);
+ mp_free_node(mp, dd,dash_node_size);
+}
+
+@ We get here when the argument is a null picture or when there is an error.
+Recovering from an error involves making |dash_list(h)| empty to indicate
+that |h| is not known to be a valid dash pattern. We also dereference |h|
+since it is not being used for the return value.
+
+@<Flush the dash list, recycle |h| and return |null|@>=
+mp_flush_dash_list(mp, h);
+delete_edge_ref(h);
+return null
+
+@ Having carefully saved the dashed stroked nodes in the
+corresponding dash nodes, we must be prepared to break up these dashes into
+smaller dashes.
+
+@<Scan |dash_list(h)| and deal with any dashes that are themselves dashed@>=
+d=h; /* now |mp_link(d)=dash_list(h)| */
+while ( mp_link(d)!=null_dash ) {
+ ds=mp_info(mp_link(d));
+ if ( ds==null ) {
+ d=mp_link(d);
+ } else {
+ hh=mp_dash_p(ds);
+ hsf=dash_scale(ds);
+ if ( (hh==null) ) mp_confusion(mp, "dash1");
+@:this can't happen dash0}{\quad dash1@>
+ if ( dash_y(hh)==0 ) {
+ d=mp_link(d);
+ } else {
+ if ( dash_list(hh)==null ) mp_confusion(mp, "dash1");
+@:this can't happen dash0}{\quad dash1@>
+ @<Replace |mp_link(d)| by a dashed version as determined by edge header
+ |hh| and scale factor |ds|@>;
+ }
+ }
+}
+
+@ @<Other local variables in |make_dashes|@>=
+pointer dln; /* |mp_link(d)| */
+pointer hh; /* an edge header that tells how to break up |dln| */
+scaled hsf; /* the dash pattern from |hh| gets scaled by this */
+pointer ds; /* the stroked node from which |hh| and |hsf| are derived */
+scaled xoff; /* added to $x$ values in |dash_list(hh)| to match |dln| */
+
+@ @<Replace |mp_link(d)| by a dashed version as determined by edge header...@>=
+dln=mp_link(d);
+dd=dash_list(hh);
+xoff=start_x(dln)-mp_take_scaled(mp, hsf,start_x(dd))-
+ mp_take_scaled(mp, hsf,mp_dash_offset(mp, hh));
+start_x(null_dash)=mp_take_scaled(mp, hsf,start_x(dd))
+ +mp_take_scaled(mp, hsf,dash_y(hh));
+stop_x(null_dash)=start_x(null_dash);
+@<Advance |dd| until finding the first dash that overlaps |dln| when
+ offset by |xoff|@>;
+while ( start_x(dln)<=stop_x(dln) ) {
+ @<If |dd| has `fallen off the end', back up to the beginning and fix |xoff|@>;
+ @<Insert a dash between |d| and |dln| for the overlap with the offset version
+ of |dd|@>;
+ dd=mp_link(dd);
+ start_x(dln)=xoff+mp_take_scaled(mp, hsf,start_x(dd));
+}
+mp_link(d)=mp_link(dln);
+mp_free_node(mp, dln,dash_node_size)
+
+@ The name of this module is a bit of a lie because we just find the
+first |dd| where |take_scaled (hsf, stop_x(dd))| is large enough to make an
+overlap possible. It could be that the unoffset version of dash |dln| falls
+in the gap between |dd| and its predecessor.
+
+@<Advance |dd| until finding the first dash that overlaps |dln| when...@>=
+while ( xoff+mp_take_scaled(mp, hsf,stop_x(dd))<start_x(dln) ) {
+ dd=mp_link(dd);
+}
+
+@ @<If |dd| has `fallen off the end', back up to the beginning and fix...@>=
+if ( dd==null_dash ) {
+ dd=dash_list(hh);
+ xoff=xoff+mp_take_scaled(mp, hsf,dash_y(hh));
+}
+
+@ At this point we already know that
+|start_x(dln)<=xoff+take_scaled(hsf,stop_x(dd))|.
+
+@<Insert a dash between |d| and |dln| for the overlap with the offset...@>=
+if ( (xoff+mp_take_scaled(mp, hsf,start_x(dd)))<=stop_x(dln) ) {
+ mp_link(d)=mp_get_node(mp, dash_node_size);
+ d=mp_link(d);
+ mp_link(d)=dln;
+ if ( start_x(dln)>(xoff+mp_take_scaled(mp, hsf,start_x(dd))))
+ start_x(d)=start_x(dln);
+ else
+ start_x(d)=xoff+mp_take_scaled(mp, hsf,start_x(dd));
+ if ( stop_x(dln)<(xoff+mp_take_scaled(mp, hsf,stop_x(dd))))
+ stop_x(d)=stop_x(dln);
+ else
+ stop_x(d)=xoff+mp_take_scaled(mp, hsf,stop_x(dd));
+}
+
+@ The next major task is to update the bounding box information in an edge
+header~|h|. This is done via a procedure |adjust_bbox| that enlarges an edge
+header's bounding box to accommodate the box computed by |path_bbox| or
+|pen_bbox|. (This is stored in global variables |minx|, |miny|, |maxx|, and
+|maxy|.)
+
+@c static void mp_adjust_bbox (MP mp,pointer h) {
+ if ( mp_minx<minx_val(h) ) minx_val(h)=mp_minx;
+ if ( mp_miny<miny_val(h) ) miny_val(h)=mp_miny;
+ if ( mp_maxx>maxx_val(h) ) maxx_val(h)=mp_maxx;
+ if ( mp_maxy>maxy_val(h) ) maxy_val(h)=mp_maxy;
+}
+
+@ Here is a special routine for updating the bounding box information in
+edge header~|h| to account for the squared-off ends of a non-cyclic path~|p|
+that is to be stroked with the pen~|pp|.
+
+@c static void mp_box_ends (MP mp, pointer p, pointer pp, pointer h) {
+ pointer q; /* a knot node adjacent to knot |p| */
+ fraction dx,dy; /* a unit vector in the direction out of the path at~|p| */
+ scaled d; /* a factor for adjusting the length of |(dx,dy)| */
+ scaled z; /* a coordinate being tested against the bounding box */
+ scaled xx,yy; /* the extreme pen vertex in the |(dx,dy)| direction */
+ integer i; /* a loop counter */
+ if ( mp_right_type(p)!=mp_endpoint ) {
+ q=mp_link(p);
+ while (1) {
+ @<Make |(dx,dy)| the final direction for the path segment from
+ |q| to~|p|; set~|d|@>;
+ d=mp_pyth_add(mp, dx,dy);
+ if ( d>0 ) {
+ @<Normalize the direction |(dx,dy)| and find the pen offset |(xx,yy)|@>;
+ for (i=1;i<= 2;i++) {
+ @<Use |(dx,dy)| to generate a vertex of the square end cap and
+ update the bounding box to accommodate it@>;
+ dx=-dx; dy=-dy;
+ }
+ }
+ if ( mp_right_type(p)==mp_endpoint ) {
+ return;
+ } else {
+ @<Advance |p| to the end of the path and make |q| the previous knot@>;
+ }
+ }
+ }
+}
+
+@ @<Make |(dx,dy)| the final direction for the path segment from...@>=
+if ( q==mp_link(p) ) {
+ dx=mp_x_coord(p)-mp_right_x(p);
+ dy=mp_y_coord(p)-mp_right_y(p);
+ if ( (dx==0)&&(dy==0) ) {
+ dx=mp_x_coord(p)-mp_left_x(q);
+ dy=mp_y_coord(p)-mp_left_y(q);
+ }
+} else {
+ dx=mp_x_coord(p)-mp_left_x(p);
+ dy=mp_y_coord(p)-mp_left_y(p);
+ if ( (dx==0)&&(dy==0) ) {
+ dx=mp_x_coord(p)-mp_right_x(q);
+ dy=mp_y_coord(p)-mp_right_y(q);
+ }
+}
+dx=mp_x_coord(p)-mp_x_coord(q);
+dy=mp_y_coord(p)-mp_y_coord(q)
+
+@ @<Normalize the direction |(dx,dy)| and find the pen offset |(xx,yy)|@>=
+dx=mp_make_fraction(mp, dx,d);
+dy=mp_make_fraction(mp, dy,d);
+mp_find_offset(mp, -dy,dx,pp);
+xx=mp->cur_x; yy=mp->cur_y
+
+@ @<Use |(dx,dy)| to generate a vertex of the square end cap and...@>=
+mp_find_offset(mp, dx,dy,pp);
+d=mp_take_fraction(mp, xx-mp->cur_x,dx)+mp_take_fraction(mp, yy-mp->cur_y,dy);
+if ( ((d<0)&&(i==1)) || ((d>0)&&(i==2)))
+ mp_confusion(mp, "box_ends");
+@:this can't happen box ends}{\quad\\{box\_ends}@>
+z=mp_x_coord(p)+mp->cur_x+mp_take_fraction(mp, d,dx);
+if ( z<minx_val(h) ) minx_val(h)=z;
+if ( z>maxx_val(h) ) maxx_val(h)=z;
+z=mp_y_coord(p)+mp->cur_y+mp_take_fraction(mp, d,dy);
+if ( z<miny_val(h) ) miny_val(h)=z;
+if ( z>maxy_val(h) ) maxy_val(h)=z
+
+@ @<Advance |p| to the end of the path and make |q| the previous knot@>=
+do {
+ q=p;
+ p=mp_link(p);
+} while (mp_right_type(p)!=mp_endpoint)
+
+@ The major difficulty in finding the bounding box of an edge structure is the
+effect of clipping paths. We treat them conservatively by only clipping to the
+clipping path's bounding box, but this still
+requires recursive calls to |set_bbox| in order to find the bounding box of
+@^recursion@>
+the objects to be clipped. Such calls are distinguished by the fact that the
+boolean parameter |top_level| is false.
+
+@c
+void mp_set_bbox (MP mp,pointer h, boolean top_level) {
+ pointer p; /* a graphical object being considered */
+ scaled sminx,sminy,smaxx,smaxy;
+ /* for saving the bounding box during recursive calls */
+ scaled x0,x1,y0,y1; /* temporary registers */
+ integer lev; /* nesting level for |mp_start_bounds_code| nodes */
+ @<Wipe out any existing bounding box information if |bbtype(h)| is
+ incompatible with |internal[mp_true_corners]|@>;
+ while ( mp_link(bblast(h))!=null ) {
+ p=mp_link(bblast(h));
+ bblast(h)=p;
+ switch (mp_type(p)) {
+ case mp_stop_clip_code:
+ if ( top_level ) mp_confusion(mp, "bbox"); else return;
+@:this can't happen bbox}{\quad bbox@>
+ break;
+ @<Other cases for updating the bounding box based on the type of object |p|@>;
+ } /* all cases are enumerated above */
+ }
+ if ( ! top_level ) mp_confusion(mp, "bbox");
+}
+
+@ @<Declarations@>=
+static void mp_set_bbox (MP mp,pointer h, boolean top_level);
+
+@ @<Wipe out any existing bounding box information if |bbtype(h)| is...@>=
+switch (bbtype(h)) {
+case no_bounds:
+ break;
+case bounds_set:
+ if ( mp->internal[mp_true_corners]>0 ) mp_init_bbox(mp, h);
+ break;
+case bounds_unset:
+ if ( mp->internal[mp_true_corners]<=0 ) mp_init_bbox(mp, h);
+ break;
+} /* there are no other cases */
+
+@ @<Other cases for updating the bounding box...@>=
+case mp_fill_code:
+ mp_path_bbox(mp, mp_path_p(p));
+ if ( mp_pen_p(p)!=null ) {
+ x0=mp_minx; y0=mp_miny;
+ x1=mp_maxx; y1=mp_maxy;
+ mp_pen_bbox(mp, mp_pen_p(p));
+ mp_minx=mp_minx+x0;
+ mp_miny=mp_miny+y0;
+ mp_maxx=mp_maxx+x1;
+ mp_maxy=mp_maxy+y1;
+ }
+ mp_adjust_bbox(mp, h);
+ break;
+
+@ @<Other cases for updating the bounding box...@>=
+case mp_start_bounds_code:
+ if ( mp->internal[mp_true_corners]>0 ) {
+ bbtype(h)=bounds_unset;
+ } else {
+ bbtype(h)=bounds_set;
+ mp_path_bbox(mp, mp_path_p(p));
+ mp_adjust_bbox(mp, h);
+ @<Scan to the matching |mp_stop_bounds_code| node and update |p| and
+ |bblast(h)|@>;
+ }
+ break;
+case mp_stop_bounds_code:
+ if ( mp->internal[mp_true_corners]<=0 ) mp_confusion(mp, "bbox2");
+@:this can't happen bbox2}{\quad bbox2@>
+ break;
+
+@ @<Scan to the matching |mp_stop_bounds_code| node and update |p| and...@>=
+lev=1;
+while ( lev!=0 ) {
+ if ( mp_link(p)==null ) mp_confusion(mp, "bbox2");
+@:this can't happen bbox2}{\quad bbox2@>
+ p=mp_link(p);
+ if ( mp_type(p)==mp_start_bounds_code ) incr(lev);
+ else if ( mp_type(p)==mp_stop_bounds_code ) decr(lev);
+}
+bblast(h)=p
+
+@ It saves a lot of grief here to be slightly conservative and not account for
+omitted parts of dashed lines. We also don't worry about the material omitted
+when using butt end caps. The basic computation is for round end caps and
+|box_ends| augments it for square end caps.
+
+@<Other cases for updating the bounding box...@>=
+case mp_stroked_code:
+ mp_path_bbox(mp, mp_path_p(p));
+ x0=mp_minx; y0=mp_miny;
+ x1=mp_maxx; y1=mp_maxy;
+ mp_pen_bbox(mp, mp_pen_p(p));
+ mp_minx=mp_minx+x0;
+ mp_miny=mp_miny+y0;
+ mp_maxx=mp_maxx+x1;
+ mp_maxy=mp_maxy+y1;
+ mp_adjust_bbox(mp, h);
+ if ( (mp_left_type(mp_path_p(p))==mp_endpoint)&&(lcap_val(p)==2) )
+ mp_box_ends(mp, mp_path_p(p), mp_pen_p(p), h);
+ break;
+
+@ The height width and depth information stored in a text node determines a
+rectangle that needs to be transformed according to the transformation
+parameters stored in the text node.
+
+@<Other cases for updating the bounding box...@>=
+case mp_text_code:
+ x1=mp_take_scaled(mp, txx_val(p),width_val(p));
+ y0=mp_take_scaled(mp, txy_val(p),-depth_val(p));
+ y1=mp_take_scaled(mp, txy_val(p),height_val(p));
+ mp_minx=tx_val(p);
+ mp_maxx=mp_minx;
+ if ( y0<y1 ) { mp_minx=mp_minx+y0; mp_maxx=mp_maxx+y1; }
+ else { mp_minx=mp_minx+y1; mp_maxx=mp_maxx+y0; }
+ if ( x1<0 ) mp_minx=mp_minx+x1; else mp_maxx=mp_maxx+x1;
+ x1=mp_take_scaled(mp, tyx_val(p),width_val(p));
+ y0=mp_take_scaled(mp, tyy_val(p),-depth_val(p));
+ y1=mp_take_scaled(mp, tyy_val(p),height_val(p));
+ mp_miny=ty_val(p);
+ mp_maxy=mp_miny;
+ if ( y0<y1 ) { mp_miny=mp_miny+y0; mp_maxy=mp_maxy+y1; }
+ else { mp_miny=mp_miny+y1; mp_maxy=mp_maxy+y0; }
+ if ( x1<0 ) mp_miny=mp_miny+x1; else mp_maxy=mp_maxy+x1;
+ mp_adjust_bbox(mp, h);
+ break;
+
+@ This case involves a recursive call that advances |bblast(h)| to the node of
+type |mp_stop_clip_code| that matches |p|.
+
+@<Other cases for updating the bounding box...@>=
+case mp_start_clip_code:
+ mp_path_bbox(mp, mp_path_p(p));
+ x0=mp_minx; y0=mp_miny;
+ x1=mp_maxx; y1=mp_maxy;
+ sminx=minx_val(h); sminy=miny_val(h);
+ smaxx=maxx_val(h); smaxy=maxy_val(h);
+ @<Reinitialize the bounding box in header |h| and call |set_bbox| recursively
+ starting at |mp_link(p)|@>;
+ @<Clip the bounding box in |h| to the rectangle given by |x0|, |x1|,
+ |y0|, |y1|@>;
+ mp_minx=sminx; mp_miny=sminy;
+ mp_maxx=smaxx; mp_maxy=smaxy;
+ mp_adjust_bbox(mp, h);
+ break;
+
+@ @<Reinitialize the bounding box in header |h| and call |set_bbox|...@>=
+minx_val(h)=el_gordo;
+miny_val(h)=el_gordo;
+maxx_val(h)=-el_gordo;
+maxy_val(h)=-el_gordo;
+mp_set_bbox(mp, h,false)
+
+@ @<Clip the bounding box in |h| to the rectangle given by |x0|, |x1|,...@>=
+if ( minx_val(h)<x0 ) minx_val(h)=x0;
+if ( miny_val(h)<y0 ) miny_val(h)=y0;
+if ( maxx_val(h)>x1 ) maxx_val(h)=x1;
+if ( maxy_val(h)>y1 ) maxy_val(h)=y1
+
+@* \[22] Finding an envelope.
+When \MP\ has a path and a polygonal pen, it needs to express the desired
+shape in terms of things \ps\ can understand. The present task is to compute
+a new path that describes the region to be filled. It is convenient to
+define this as a two step process where the first step is determining what
+offset to use for each segment of the path.
+
+@ Given a pointer |c| to a cyclic path,
+and a pointer~|h| to the first knot of a pen polygon,
+the |offset_prep| routine changes the path into cubics that are
+associated with particular pen offsets. Thus if the cubic between |p|
+and~|q| is associated with the |k|th offset and the cubic between |q| and~|r|
+has offset |l| then |mp_info(q)=zero_off+l-k|. (The constant |zero_off| is added
+to because |l-k| could be negative.)
+
+After overwriting the type information with offset differences, we no longer
+have a true path so we refer to the knot list returned by |offset_prep| as an
+``envelope spec.''
+@^envelope spec@>
+Since an envelope spec only determines relative changes in pen offsets,
+|offset_prep| sets a global variable |spec_offset| to the relative change from
+|h| to the first offset.
+
+@d zero_off 16384 /* added to offset changes to make them positive */
+
+@<Glob...@>=
+integer spec_offset; /* number of pen edges between |h| and the initial offset */
+
+@ @c
+static pointer mp_offset_prep (MP mp,pointer c, pointer h) {
+ halfword n; /* the number of vertices in the pen polygon */
+ pointer c0,p,q,q0,r,w, ww; /* for list manipulation */
+ integer k_needed; /* amount to be added to |mp_info(p)| when it is computed */
+ pointer w0; /* a pointer to pen offset to use just before |p| */
+ scaled dxin,dyin; /* the direction into knot |p| */
+ integer turn_amt; /* change in pen offsets for the current cubic */
+ @<Other local variables for |offset_prep|@>;
+ dx0=0; dy0=0;
+ @<Initialize the pen size~|n|@>;
+ @<Initialize the incoming direction and pen offset at |c|@>;
+ p=c; c0=c; k_needed=0;
+ do {
+ q=mp_link(p);
+ @<Split the cubic between |p| and |q|, if necessary, into cubics
+ associated with single offsets, after which |q| should
+ point to the end of the final such cubic@>;
+ NOT_FOUND:
+ @<Advance |p| to node |q|, removing any ``dead'' cubics that
+ might have been introduced by the splitting process@>;
+ } while (q!=c);
+ @<Fix the offset change in |mp_info(c)| and set |c| to the return value of
+ |offset_prep|@>;
+ return c;
+}
+
+@ We shall want to keep track of where certain knots on the cyclic path
+wind up in the envelope spec. It doesn't suffice just to keep pointers to
+knot nodes because some nodes are deleted while removing dead cubics. Thus
+|offset_prep| updates the following pointers
+
+@<Glob...@>=
+pointer spec_p1;
+pointer spec_p2; /* pointers to distinguished knots */
+
+@ @<Set init...@>=
+mp->spec_p1=null; mp->spec_p2=null;
+
+@ @<Initialize the pen size~|n|@>=
+n=0; p=h;
+do {
+ incr(n);
+ p=mp_link(p);
+} while (p!=h)
+
+@ Since the true incoming direction isn't known yet, we just pick a direction
+consistent with the pen offset~|h|. If this is wrong, it can be corrected
+later.
+
+@<Initialize the incoming direction and pen offset at |c|@>=
+dxin=mp_x_coord(mp_link(h))-mp_x_coord(knil(h));
+dyin=mp_y_coord(mp_link(h))-mp_y_coord(knil(h));
+if ( (dxin==0)&&(dyin==0) ) {
+ dxin=mp_y_coord(knil(h))-mp_y_coord(h);
+ dyin=mp_x_coord(h)-mp_x_coord(knil(h));
+}
+w0=h
+
+@ We must be careful not to remove the only cubic in a cycle.
+
+But we must also be careful for another reason. If the user-supplied
+path starts with a set of degenerate cubics, the target node |q| can
+be collapsed to the initial node |p| which might be the same as the
+initial node |c| of the curve. This would cause the |offset_prep| routine
+to bail out too early, causing distress later on. (See for example
+the testcase reported by Bogus\l{}aw Jackowski in tracker id 267, case 52c
+on Sarovar.)
+
+@<Advance |p| to node |q|, removing any ``dead'' cubics...@>=
+q0=q;
+do {
+ r=mp_link(p);
+ if ( mp_x_coord(p)==mp_right_x(p) && mp_y_coord(p)==mp_right_y(p) &&
+ mp_x_coord(p)==mp_left_x(r) && mp_y_coord(p)==mp_left_y(r) &&
+ mp_x_coord(p)==mp_x_coord(r) && mp_y_coord(p)==mp_y_coord(r) &&
+ r!=p ) {
+ @<Remove the cubic following |p| and update the data structures
+ to merge |r| into |p|@>;
+ }
+ p=r;
+} while (p!=q);
+/* Check if we removed too much */
+if ((q!=q0)&&(q!=c||c==c0))
+ q = mp_link(q)
+
+@ @<Remove the cubic following |p| and update the data structures...@>=
+{ k_needed=mp_info(p)-zero_off;
+ if ( r==q ) {
+ q=p;
+ } else {
+ mp_info(p)=k_needed+mp_info(r);
+ k_needed=0;
+ };
+ if ( r==c ) { mp_info(p)=mp_info(c); c=p; };
+ if ( r==mp->spec_p1 ) mp->spec_p1=p;
+ if ( r==mp->spec_p2 ) mp->spec_p2=p;
+ r=p; mp_remove_cubic(mp, p);
+}
+
+@ Not setting the |info| field of the newly created knot allows the splitting
+routine to work for paths.
+
+@<Declarations@>=
+static void mp_split_cubic (MP mp,pointer p, fraction t) ;
+
+@ @c
+void mp_split_cubic (MP mp,pointer p, fraction t) { /* splits the cubic after |p| */
+ scaled v; /* an intermediate value */
+ pointer q,r; /* for list manipulation */
+ q=mp_link(p); r=mp_get_node(mp, knot_node_size); mp_link(p)=r; mp_link(r)=q;
+ mp_originator(r)=mp_program_code;
+ mp_left_type(r)=mp_explicit; mp_right_type(r)=mp_explicit;
+ v=t_of_the_way(mp_right_x(p),mp_left_x(q));
+ mp_right_x(p)=t_of_the_way(mp_x_coord(p),mp_right_x(p));
+ mp_left_x(q)=t_of_the_way(mp_left_x(q),mp_x_coord(q));
+ mp_left_x(r)=t_of_the_way(mp_right_x(p),v);
+ mp_right_x(r)=t_of_the_way(v,mp_left_x(q));
+ mp_x_coord(r)=t_of_the_way(mp_left_x(r),mp_right_x(r));
+ v=t_of_the_way(mp_right_y(p),mp_left_y(q));
+ mp_right_y(p)=t_of_the_way(mp_y_coord(p),mp_right_y(p));
+ mp_left_y(q)=t_of_the_way(mp_left_y(q),mp_y_coord(q));
+ mp_left_y(r)=t_of_the_way(mp_right_y(p),v);
+ mp_right_y(r)=t_of_the_way(v,mp_left_y(q));
+ mp_y_coord(r)=t_of_the_way(mp_left_y(r),mp_right_y(r));
+}
+
+@ This does not set |mp_info(p)| or |mp_right_type(p)|.
+
+@<Declarations@>=
+static void mp_remove_cubic (MP mp,pointer p) ;
+
+@ @c
+void mp_remove_cubic (MP mp,pointer p) { /* removes the dead cubic following~|p| */
+ pointer q; /* the node that disappears */
+ q=mp_link(p); mp_link(p)=mp_link(q);
+ mp_right_x(p)=mp_right_x(q); mp_right_y(p)=mp_right_y(q);
+ mp_free_node(mp, q,knot_node_size);
+}
+
+@ Let $d\prec d'$ mean that the counter-clockwise angle from $d$ to~$d'$ is
+strictly between zero and $180^\circ$. Then we can define $d\preceq d'$ to
+mean that the angle could be zero or $180^\circ$. If $w_k=(u_k,v_k)$ is the
+$k$th pen offset, the $k$th pen edge direction is defined by the formula
+$$d_k=(u\k-u_k,\,v\k-v_k).$$
+When listed by increasing $k$, these directions occur in counter-clockwise
+order so that $d_k\preceq d\k$ for all~$k$.
+The goal of |offset_prep| is to find an offset index~|k| to associate with
+each cubic, such that the direction $d(t)$ of the cubic satisfies
+$$d_{k-1}\preceq d(t)\preceq d_k\qquad\hbox{for $0\le t\le 1$.}\eqno(*)$$
+We may have to split a cubic into many pieces before each
+piece corresponds to a unique offset.
+
+@<Split the cubic between |p| and |q|, if necessary, into cubics...@>=
+mp_info(p)=zero_off+k_needed;
+k_needed=0;
+@<Prepare for derivative computations;
+ |goto not_found| if the current cubic is dead@>;
+@<Find the initial direction |(dx,dy)|@>;
+@<Update |mp_info(p)| and find the offset $w_k$ such that
+ $d_{k-1}\preceq(\\{dx},\\{dy})\prec d_k$; also advance |w0| for
+ the direction change at |p|@>;
+@<Find the final direction |(dxin,dyin)|@>;
+@<Decide on the net change in pen offsets and set |turn_amt|@>;
+@<Complete the offset splitting process@>;
+w0=mp_pen_walk(mp, w0,turn_amt)
+
+@ @<Declarations@>=
+static pointer mp_pen_walk (MP mp,pointer w, integer k) ;
+
+@ @c
+pointer mp_pen_walk (MP mp,pointer w, integer k) {
+ /* walk |k| steps around a pen from |w| */
+ while ( k>0 ) { w=mp_link(w); decr(k); };
+ while ( k<0 ) { w=knil(w); incr(k); };
+ return w;
+}
+
+@ The direction of a cubic $B(z_0,z_1,z_2,z_3;t)=\bigl(x(t),y(t)\bigr)$ can be
+calculated from the quadratic polynomials
+${1\over3}x'(t)=B(x_1-x_0,x_2-x_1,x_3-x_2;t)$ and
+${1\over3}y'(t)=B(y_1-y_0,y_2-y_1,y_3-y_2;t)$.
+Since we may be calculating directions from several cubics
+split from the current one, it is desirable to do these calculations
+without losing too much precision. ``Scaled up'' values of the
+derivatives, which will be less tainted by accumulated errors than
+derivatives found from the cubics themselves, are maintained in
+local variables |x0|, |x1|, and |x2|, representing $X_0=2^l(x_1-x_0)$,
+$X_1=2^l(x_2-x_1)$, and $X_2=2^l(x_3-x_2)$; similarly |y0|, |y1|, and~|y2|
+represent $Y_0=2^l(y_1-y_0)$, $Y_1=2^l(y_2-y_1)$, and $Y_2=2^l(y_3-y_2)$.
+
+@<Other local variables for |offset_prep|@>=
+integer x0,x1,x2,y0,y1,y2; /* representatives of derivatives */
+integer t0,t1,t2; /* coefficients of polynomial for slope testing */
+integer du,dv,dx,dy; /* for directions of the pen and the curve */
+integer dx0,dy0; /* initial direction for the first cubic in the curve */
+integer max_coef; /* used while scaling */
+integer x0a,x1a,x2a,y0a,y1a,y2a; /* intermediate values */
+fraction t; /* where the derivative passes through zero */
+fraction s; /* a temporary value */
+
+@ @<Prepare for derivative computations...@>=
+x0=mp_right_x(p)-mp_x_coord(p);
+x2=mp_x_coord(q)-mp_left_x(q);
+x1=mp_left_x(q)-mp_right_x(p);
+y0=mp_right_y(p)-mp_y_coord(p); y2=mp_y_coord(q)-mp_left_y(q);
+y1=mp_left_y(q)-mp_right_y(p);
+max_coef=abs(x0);
+if ( abs(x1)>max_coef ) max_coef=abs(x1);
+if ( abs(x2)>max_coef ) max_coef=abs(x2);
+if ( abs(y0)>max_coef ) max_coef=abs(y0);
+if ( abs(y1)>max_coef ) max_coef=abs(y1);
+if ( abs(y2)>max_coef ) max_coef=abs(y2);
+if ( max_coef==0 ) goto NOT_FOUND;
+while ( max_coef<fraction_half ) {
+ double(max_coef);
+ double(x0); double(x1); double(x2);
+ double(y0); double(y1); double(y2);
+}
+
+@ Let us first solve a special case of the problem: Suppose we
+know an index~$k$ such that either (i)~$d(t)\succeq d_{k-1}$ for all~$t$
+and $d(0)\prec d_k$, or (ii)~$d(t)\preceq d_k$ for all~$t$ and
+$d(0)\succ d_{k-1}$.
+Then, in a sense, we're halfway done, since one of the two relations
+in $(*)$ is satisfied, and the other couldn't be satisfied for
+any other value of~|k|.
+
+Actually, the conditions can be relaxed somewhat since a relation such as
+$d(t)\succeq d_{k-1}$ restricts $d(t)$ to a half plane when all that really
+matters is whether $d(t)$ crosses the ray in the $d_{k-1}$ direction from
+the origin. The condition for case~(i) becomes $d_{k-1}\preceq d(0)\prec d_k$
+and $d(t)$ never crosses the $d_{k-1}$ ray in the clockwise direction.
+Case~(ii) is similar except $d(t)$ cannot cross the $d_k$ ray in the
+counterclockwise direction.
+
+The |fin_offset_prep| subroutine solves the stated subproblem.
+It has a parameter called |rise| that is |1| in
+case~(i), |-1| in case~(ii). Parameters |x0| through |y2| represent
+the derivative of the cubic following |p|.
+The |w| parameter should point to offset~$w_k$ and |mp_info(p)| should already
+be set properly. The |turn_amt| parameter gives the absolute value of the
+overall net change in pen offsets.
+
+@<Declarations@>=
+static void mp_fin_offset_prep (MP mp,pointer p, pointer w, integer
+ x0,integer x1, integer x2, integer y0, integer y1, integer y2,
+ integer rise, integer turn_amt) ;
+
+@ @c
+void mp_fin_offset_prep (MP mp,pointer p, pointer w, integer
+ x0,integer x1, integer x2, integer y0, integer y1, integer y2,
+ integer rise, integer turn_amt) {
+ pointer ww; /* for list manipulation */
+ scaled du,dv; /* for slope calculation */
+ integer t0,t1,t2; /* test coefficients */
+ fraction t; /* place where the derivative passes a critical slope */
+ fraction s; /* slope or reciprocal slope */
+ integer v; /* intermediate value for updating |x0..y2| */
+ pointer q; /* original |mp_link(p)| */
+ q=mp_link(p);
+ while (1) {
+ if ( rise>0 ) ww=mp_link(w); /* a pointer to $w\k$ */
+ else ww=knil(w); /* a pointer to $w_{k-1}$ */
+ @<Compute test coefficients |(t0,t1,t2)|
+ for $d(t)$ versus $d_k$ or $d_{k-1}$@>;
+ t=mp_crossing_point(mp, t0,t1,t2);
+ if ( t>=fraction_one ) {
+ if ( turn_amt>0 ) t=fraction_one; else return;
+ }
+ @<Split the cubic at $t$,
+ and split off another cubic if the derivative crosses back@>;
+ w=ww;
+ }
+}
+
+@ We want $B(\\{t0},\\{t1},\\{t2};t)$ to be the dot product of $d(t)$ with a
+$-90^\circ$ rotation of the vector from |w| to |ww|. This makes the resulting
+function cross from positive to negative when $d_{k-1}\preceq d(t)\preceq d_k$
+begins to fail.
+
+@<Compute test coefficients |(t0,t1,t2)| for $d(t)$ versus...@>=
+du=mp_x_coord(ww)-mp_x_coord(w); dv=mp_y_coord(ww)-mp_y_coord(w);
+if ( abs(du)>=abs(dv) ) {
+ s=mp_make_fraction(mp, dv,du);
+ t0=mp_take_fraction(mp, x0,s)-y0;
+ t1=mp_take_fraction(mp, x1,s)-y1;
+ t2=mp_take_fraction(mp, x2,s)-y2;
+ if ( du<0 ) { negate(t0); negate(t1); negate(t2); }
+} else {
+ s=mp_make_fraction(mp, du,dv);
+ t0=x0-mp_take_fraction(mp, y0,s);
+ t1=x1-mp_take_fraction(mp, y1,s);
+ t2=x2-mp_take_fraction(mp, y2,s);
+ if ( dv<0 ) { negate(t0); negate(t1); negate(t2); }
+}
+if ( t0<0 ) t0=0 /* should be positive without rounding error */
+
+@ The curve has crossed $d_k$ or $d_{k-1}$; its initial segment satisfies
+$(*)$, and it might cross again and return towards $s_{k-1}$ or $s_k$,
+respectively, yielding another solution of $(*)$.
+
+@<Split the cubic at $t$, and split off another...@>=
+{
+mp_split_cubic(mp, p,t); p=mp_link(p); mp_info(p)=zero_off+rise;
+decr(turn_amt);
+v=t_of_the_way(x0,x1); x1=t_of_the_way(x1,x2);
+x0=t_of_the_way(v,x1);
+v=t_of_the_way(y0,y1); y1=t_of_the_way(y1,y2);
+y0=t_of_the_way(v,y1);
+if ( turn_amt<0 ) {
+ t1=t_of_the_way(t1,t2);
+ if ( t1>0 ) t1=0; /* without rounding error, |t1| would be |<=0| */
+ t=mp_crossing_point(mp, 0,-t1,-t2);
+ if ( t>fraction_one ) t=fraction_one;
+ incr(turn_amt);
+ if ( (t==fraction_one)&&(mp_link(p)!=q) ) {
+ mp_info(mp_link(p))=mp_info(mp_link(p))-rise;
+ } else {
+ mp_split_cubic(mp, p,t); mp_info(mp_link(p))=zero_off-rise;
+ v=t_of_the_way(x1,x2); x1=t_of_the_way(x0,x1);
+ x2=t_of_the_way(x1,v);
+ v=t_of_the_way(y1,y2); y1=t_of_the_way(y0,y1);
+ y2=t_of_the_way(y1,v);
+ }
+}
+}
+
+@ Now we must consider the general problem of |offset_prep|, when
+nothing is known about a given cubic. We start by finding its
+direction in the vicinity of |t=0|.
+
+If $z'(t)=0$, the given cubic is numerically unstable but |offset_prep|
+has not yet introduced any more numerical errors. Thus we can compute
+the true initial direction for the given cubic, even if it is almost
+degenerate.
+
+@<Find the initial direction |(dx,dy)|@>=
+dx=x0; dy=y0;
+if ( dx==0 && dy==0 ) {
+ dx=x1; dy=y1;
+ if ( dx==0 && dy==0 ) {
+ dx=x2; dy=y2;
+ }
+}
+if ( p==c ) { dx0=dx; dy0=dy; }
+
+@ @<Find the final direction |(dxin,dyin)|@>=
+dxin=x2; dyin=y2;
+if ( dxin==0 && dyin==0 ) {
+ dxin=x1; dyin=y1;
+ if ( dxin==0 && dyin==0 ) {
+ dxin=x0; dyin=y0;
+ }
+}
+
+@ The next step is to bracket the initial direction between consecutive
+edges of the pen polygon. We must be careful to turn clockwise only if
+this makes the turn less than $180^\circ$. (A $180^\circ$ turn must be
+counter-clockwise in order to make \&{doublepath} envelopes come out
+@:double_path_}{\&{doublepath} primitive@>
+right.) This code depends on |w0| being the offset for |(dxin,dyin)|.
+
+@<Update |mp_info(p)| and find the offset $w_k$ such that...@>=
+turn_amt=mp_get_turn_amt(mp,w0,dx,dy,(mp_ab_vs_cd(mp, dy,dxin,dx,dyin)>=0));
+w=mp_pen_walk(mp, w0, turn_amt);
+w0=w;
+mp_info(p)=mp_info(p)+turn_amt
+
+@ Decide how many pen offsets to go away from |w| in order to find the offset
+for |(dx,dy)|, going counterclockwise if |ccw| is |true|. This assumes that
+|w| is the offset for some direction $(x',y')$ from which the angle to |(dx,dy)|
+in the sense determined by |ccw| is less than or equal to $180^\circ$.
+
+If the pen polygon has only two edges, they could both be parallel
+to |(dx,dy)|. In this case, we must be careful to stop after crossing the first
+such edge in order to avoid an infinite loop.
+
+@<Declarations@>=
+static integer mp_get_turn_amt (MP mp,pointer w, scaled dx,
+ scaled dy, boolean ccw);
+
+@ @c
+integer mp_get_turn_amt (MP mp,pointer w, scaled dx,
+ scaled dy, boolean ccw) {
+ pointer ww; /* a neighbor of knot~|w| */
+ integer s; /* turn amount so far */
+ integer t; /* |ab_vs_cd| result */
+ s=0;
+ if ( ccw ) {
+ ww=mp_link(w);
+ do {
+ t=mp_ab_vs_cd(mp, dy,(mp_x_coord(ww)-mp_x_coord(w)),
+ dx,(mp_y_coord(ww)-mp_y_coord(w)));
+ if ( t<0 ) break;
+ incr(s);
+ w=ww; ww=mp_link(ww);
+ } while (t>0);
+ } else {
+ ww=knil(w);
+ while ( mp_ab_vs_cd(mp, dy,(mp_x_coord(w)-mp_x_coord(ww)),
+ dx,(mp_y_coord(w)-mp_y_coord(ww))) < 0) {
+ decr(s);
+ w=ww; ww=knil(ww);
+ }
+ }
+ return s;
+}
+
+@ When we're all done, the final offset is |w0| and the final curve direction
+is |(dxin,dyin)|. With this knowledge of the incoming direction at |c|, we
+can correct |mp_info(c)| which was erroneously based on an incoming offset
+of~|h|.
+
+@d fix_by(A) mp_info(c)=mp_info(c)+(A)
+
+@<Fix the offset change in |mp_info(c)| and set |c| to the return value of...@>=
+mp->spec_offset=mp_info(c)-zero_off;
+if ( mp_link(c)==c ) {
+ mp_info(c)=zero_off+n;
+} else {
+ fix_by(k_needed);
+ while ( w0!=h ) { fix_by(1); w0=mp_link(w0); };
+ while ( mp_info(c)<=zero_off-n ) fix_by(n);
+ while ( mp_info(c)>zero_off ) fix_by(-n);
+ if ( (mp_info(c)!=zero_off)&&(mp_ab_vs_cd(mp, dy0,dxin,dx0,dyin)>=0) ) fix_by(n);
+}
+
+@ Finally we want to reduce the general problem to situations that
+|fin_offset_prep| can handle. We split the cubic into at most three parts
+with respect to $d_{k-1}$, and apply |fin_offset_prep| to each part.
+
+@<Complete the offset splitting process@>=
+ww=knil(w);
+@<Compute test coeff...@>;
+@<Find the first |t| where $d(t)$ crosses $d_{k-1}$ or set
+ |t:=fraction_one+1|@>;
+if ( t>fraction_one ) {
+ mp_fin_offset_prep(mp, p,w,x0,x1,x2,y0,y1,y2,1,turn_amt);
+} else {
+ mp_split_cubic(mp, p,t); r=mp_link(p);
+ x1a=t_of_the_way(x0,x1); x1=t_of_the_way(x1,x2);
+ x2a=t_of_the_way(x1a,x1);
+ y1a=t_of_the_way(y0,y1); y1=t_of_the_way(y1,y2);
+ y2a=t_of_the_way(y1a,y1);
+ mp_fin_offset_prep(mp, p,w,x0,x1a,x2a,y0,y1a,y2a,1,0); x0=x2a; y0=y2a;
+ mp_info(r)=zero_off-1;
+ if ( turn_amt>=0 ) {
+ t1=t_of_the_way(t1,t2);
+ if ( t1>0 ) t1=0;
+ t=mp_crossing_point(mp, 0,-t1,-t2);
+ if ( t>fraction_one ) t=fraction_one;
+ @<Split off another rising cubic for |fin_offset_prep|@>;
+ mp_fin_offset_prep(mp, r,ww,x0,x1,x2,y0,y1,y2,-1,0);
+ } else {
+ mp_fin_offset_prep(mp, r,ww,x0,x1,x2,y0,y1,y2,-1,(-1-turn_amt));
+ }
+}
+
+@ @<Split off another rising cubic for |fin_offset_prep|@>=
+mp_split_cubic(mp, r,t); mp_info(mp_link(r))=zero_off+1;
+x1a=t_of_the_way(x1,x2); x1=t_of_the_way(x0,x1);
+x0a=t_of_the_way(x1,x1a);
+y1a=t_of_the_way(y1,y2); y1=t_of_the_way(y0,y1);
+y0a=t_of_the_way(y1,y1a);
+mp_fin_offset_prep(mp, mp_link(r),w,x0a,x1a,x2,y0a,y1a,y2,1,turn_amt);
+x2=x0a; y2=y0a
+
+@ At this point, the direction of the incoming pen edge is |(-du,-dv)|.
+When the component of $d(t)$ perpendicular to |(-du,-dv)| crosses zero, we
+need to decide whether the directions are parallel or antiparallel. We
+can test this by finding the dot product of $d(t)$ and |(-du,-dv)|, but this
+should be avoided when the value of |turn_amt| already determines the
+answer. If |t2<0|, there is one crossing and it is antiparallel only if
+|turn_amt>=0|. If |turn_amt<0|, there should always be at least one
+crossing and the first crossing cannot be antiparallel.
+
+@<Find the first |t| where $d(t)$ crosses $d_{k-1}$ or set...@>=
+t=mp_crossing_point(mp, t0,t1,t2);
+if ( turn_amt>=0 ) {
+ if ( t2<0 ) {
+ t=fraction_one+1;
+ } else {
+ u0=t_of_the_way(x0,x1);
+ u1=t_of_the_way(x1,x2);
+ ss=mp_take_fraction(mp, -du,t_of_the_way(u0,u1));
+ v0=t_of_the_way(y0,y1);
+ v1=t_of_the_way(y1,y2);
+ ss=ss+mp_take_fraction(mp, -dv,t_of_the_way(v0,v1));
+ if ( ss<0 ) t=fraction_one+1;
+ }
+} else if ( t>fraction_one ) {
+ t=fraction_one;
+}
+
+@ @<Other local variables for |offset_prep|@>=
+integer u0,u1,v0,v1; /* intermediate values for $d(t)$ calculation */
+integer ss = 0; /* the part of the dot product computed so far */
+int d_sign; /* sign of overall change in direction for this cubic */
+
+@ If the cubic almost has a cusp, it is a numerically ill-conditioned
+problem to decide which way it loops around but that's OK as long we're
+consistent. To make \&{doublepath} envelopes work properly, reversing
+the path should always change the sign of |turn_amt|.
+
+@<Decide on the net change in pen offsets and set |turn_amt|@>=
+d_sign=mp_ab_vs_cd(mp, dx,dyin, dxin,dy);
+if ( d_sign==0 ) {
+ @<Check rotation direction based on node position@>
+}
+if ( d_sign==0 ) {
+ if ( dx==0 ) {
+ if ( dy>0 ) d_sign=1; else d_sign=-1;
+ } else {
+ if ( dx>0 ) d_sign=1; else d_sign=-1;
+ }
+}
+@<Make |ss| negative if and only if the total change in direction is
+ more than $180^\circ$@>;
+turn_amt=mp_get_turn_amt(mp, w, dxin, dyin, (d_sign>0));
+if ( ss<0 ) turn_amt=turn_amt-d_sign*n
+
+@ We check rotation direction by looking at the vector connecting the current
+node with the next. If its angle with incoming and outgoing tangents has the
+same sign, we pick this as |d_sign|, since it means we have a flex, not a cusp.
+Otherwise we proceed to the cusp code.
+
+@<Check rotation direction based on node position@>=
+u0=mp_x_coord(q)-mp_x_coord(p);
+u1=mp_y_coord(q)-mp_y_coord(p);
+d_sign = half(mp_ab_vs_cd(mp, dx, u1, u0, dy)+
+ mp_ab_vs_cd(mp, u0, dyin, dxin, u1));
+
+@ In order to be invariant under path reversal, the result of this computation
+should not change when |x0|, |y0|, $\ldots$ are all negated and |(x0,y0)| is
+then swapped with |(x2,y2)|. We make use of the identities
+|take_fraction(-a,-b)=take_fraction(a,b)| and
+|t_of_the_way(-a,-b)=-(t_of_the_way(a,b))|.
+
+@<Make |ss| negative if and only if the total change in direction is...@>=
+t0=half(mp_take_fraction(mp, x0,y2))-half(mp_take_fraction(mp, x2,y0));
+t1=half(mp_take_fraction(mp, x1,(y0+y2)))-half(mp_take_fraction(mp, y1,(x0+x2)));
+if ( t0==0 ) t0=d_sign; /* path reversal always negates |d_sign| */
+if ( t0>0 ) {
+ t=mp_crossing_point(mp, t0,t1,-t0);
+ u0=t_of_the_way(x0,x1);
+ u1=t_of_the_way(x1,x2);
+ v0=t_of_the_way(y0,y1);
+ v1=t_of_the_way(y1,y2);
+} else {
+ t=mp_crossing_point(mp, -t0,t1,t0);
+ u0=t_of_the_way(x2,x1);
+ u1=t_of_the_way(x1,x0);
+ v0=t_of_the_way(y2,y1);
+ v1=t_of_the_way(y1,y0);
+}
+ss=mp_take_fraction(mp, (x0+x2),t_of_the_way(u0,u1))+
+ mp_take_fraction(mp, (y0+y2),t_of_the_way(v0,v1))
+
+@ Here's a routine that prints an envelope spec in symbolic form. It assumes
+that the |cur_pen| has not been walked around to the first offset.
+
+@c
+static void mp_print_spec (MP mp,pointer cur_spec, pointer cur_pen, const char *s) {
+ pointer p,q; /* list traversal */
+ pointer w; /* the current pen offset */
+ mp_print_diagnostic(mp, "Envelope spec",s,true);
+ p=cur_spec; w=mp_pen_walk(mp, cur_pen,mp->spec_offset);
+ mp_print_ln(mp);
+ mp_print_two(mp, mp_x_coord(cur_spec),mp_y_coord(cur_spec));
+ mp_print(mp, " % beginning with offset ");
+ mp_print_two(mp, mp_x_coord(w),mp_y_coord(w));
+ do {
+ while (1) {
+ q=mp_link(p);
+ @<Print the cubic between |p| and |q|@>;
+ p=q;
+ if ((p==cur_spec) || (mp_info(p)!=zero_off))
+ break;
+ }
+ if ( mp_info(p)!=zero_off ) {
+ @<Update |w| as indicated by |mp_info(p)| and print an explanation@>;
+ }
+ } while (p!=cur_spec);
+ mp_print_nl(mp, " & cycle");
+ mp_end_diagnostic(mp, true);
+}
+
+@ @<Update |w| as indicated by |mp_info(p)| and print an explanation@>=
+{
+ w=mp_pen_walk(mp, w, (mp_info(p)-zero_off));
+ mp_print(mp, " % ");
+ if ( mp_info(p)>zero_off ) mp_print(mp, "counter");
+ mp_print(mp, "clockwise to offset ");
+ mp_print_two(mp, mp_x_coord(w),mp_y_coord(w));
+}
+
+@ @<Print the cubic between |p| and |q|@>=
+{
+ mp_print_nl(mp, " ..controls ");
+ mp_print_two(mp, mp_right_x(p),mp_right_y(p));
+ mp_print(mp, " and ");
+ mp_print_two(mp, mp_left_x(q),mp_left_y(q));
+ mp_print_nl(mp, " ..");
+ mp_print_two(mp, mp_x_coord(q),mp_y_coord(q));
+}
+
+@ Once we have an envelope spec, the remaining task to construct the actual
+envelope by offsetting each cubic as determined by the |info| fields in
+the knots. First we use |offset_prep| to convert the |c| into an envelope
+spec. Then we add the offsets so that |c| becomes a cyclic path that represents
+the envelope.
+
+The |ljoin| and |miterlim| parameters control the treatment of points where the
+pen offset changes, and |lcap| controls the endpoints of a \&{doublepath}.
+The endpoints are easily located because |c| is given in undoubled form
+and then doubled in this procedure. We use |spec_p1| and |spec_p2| to keep
+track of the endpoints and treat them like very sharp corners.
+Butt end caps are treated like beveled joins; round end caps are treated like
+round joins; and square end caps are achieved by setting |join_type:=3|.
+
+None of these parameters apply to inside joins where the convolution tracing
+has retrograde lines. In such cases we use a simple connect-the-endpoints
+approach that is achieved by setting |join_type:=2|.
+
+@c
+static pointer mp_make_envelope (MP mp,pointer c, pointer h, quarterword ljoin,
+ quarterword lcap, scaled miterlim) {
+ pointer p,q,r,q0; /* for manipulating the path */
+ int join_type=0; /* codes |0..3| for mitered, round, beveled, or square */
+ pointer w,w0; /* the pen knot for the current offset */
+ scaled qx,qy; /* unshifted coordinates of |q| */
+ halfword k,k0; /* controls pen edge insertion */
+ @<Other local variables for |make_envelope|@>;
+ dxin=0; dyin=0; dxout=0; dyout=0;
+ mp->spec_p1=null; mp->spec_p2=null;
+ @<If endpoint, double the path |c|, and set |spec_p1| and |spec_p2|@>;
+ @<Use |offset_prep| to compute the envelope spec then walk |h| around to
+ the initial offset@>;
+ w=h;
+ p=c;
+ do {
+ q=mp_link(p); q0=q;
+ qx=mp_x_coord(q); qy=mp_y_coord(q);
+ k=mp_info(q);
+ k0=k; w0=w;
+ if ( k!=zero_off ) {
+ @<Set |join_type| to indicate how to handle offset changes at~|q|@>;
+ }
+ @<Add offset |w| to the cubic from |p| to |q|@>;
+ while ( k!=zero_off ) {
+ @<Step |w| and move |k| one step closer to |zero_off|@>;
+ if ( (join_type==1)||(k==zero_off) )
+ q=mp_insert_knot(mp, q,qx+mp_x_coord(w),qy+mp_y_coord(w));
+ };
+ if ( q!=mp_link(p) ) {
+ @<Set |p=mp_link(p)| and add knots between |p| and |q| as
+ required by |join_type|@>;
+ }
+ p=q;
+ } while (q0!=c);
+ return c;
+}
+
+@ @<Use |offset_prep| to compute the envelope spec then walk |h| around to...@>=
+c=mp_offset_prep(mp, c,h);
+if ( mp->internal[mp_tracing_specs]>0 )
+ mp_print_spec(mp, c,h,"");
+h=mp_pen_walk(mp, h,mp->spec_offset)
+
+@ Mitered and squared-off joins depend on path directions that are difficult to
+compute for degenerate cubics. The envelope spec computed by |offset_prep| can
+have degenerate cubics only if the entire cycle collapses to a single
+degenerate cubic. Setting |join_type:=2| in this case makes the computed
+envelope degenerate as well.
+
+@<Set |join_type| to indicate how to handle offset changes at~|q|@>=
+if ( k<zero_off ) {
+ join_type=2;
+} else {
+ if ( (q!=mp->spec_p1)&&(q!=mp->spec_p2) ) join_type=ljoin;
+ else if ( lcap==2 ) join_type=3;
+ else join_type=2-lcap;
+ if ( (join_type==0)||(join_type==3) ) {
+ @<Set the incoming and outgoing directions at |q|; in case of
+ degeneracy set |join_type:=2|@>;
+ if ( join_type==0 ) {
+ @<If |miterlim| is less than the secant of half the angle at |q|
+ then set |join_type:=2|@>;
+ }
+ }
+}
+
+@ @<If |miterlim| is less than the secant of half the angle at |q|...@>=
+{
+ tmp=mp_take_fraction(mp, miterlim,fraction_half+
+ half(mp_take_fraction(mp, dxin,dxout)+mp_take_fraction(mp, dyin,dyout)));
+ if ( tmp<unity )
+ if ( mp_take_scaled(mp, miterlim,tmp)<unity ) join_type=2;
+}
+
+@ @<Other local variables for |make_envelope|@>=
+fraction dxin,dyin,dxout,dyout; /* directions at |q| when square or mitered */
+scaled tmp; /* a temporary value */
+
+@ The coordinates of |p| have already been shifted unless |p| is the first
+knot in which case they get shifted at the very end.
+
+@<Add offset |w| to the cubic from |p| to |q|@>=
+mp_right_x(p)=mp_right_x(p)+mp_x_coord(w);
+mp_right_y(p)=mp_right_y(p)+mp_y_coord(w);
+mp_left_x(q)=mp_left_x(q)+mp_x_coord(w);
+mp_left_y(q)=mp_left_y(q)+mp_y_coord(w);
+mp_x_coord(q)=mp_x_coord(q)+mp_x_coord(w);
+mp_y_coord(q)=mp_y_coord(q)+mp_y_coord(w);
+mp_left_type(q)=mp_explicit;
+mp_right_type(q)=mp_explicit
+
+@ @<Step |w| and move |k| one step closer to |zero_off|@>=
+if ( k>zero_off ){ w=mp_link(w); decr(k); }
+else { w=knil(w); incr(k); }
+
+@ The cubic from |q| to the new knot at |(x,y)| becomes a line segment and
+the |mp_right_x| and |mp_right_y| fields of |r| are set from |q|. This is done in
+case the cubic containing these control points is ``yet to be examined.''
+
+@<Declarations@>=
+static pointer mp_insert_knot (MP mp,pointer q, scaled x, scaled y);
+
+@ @c
+pointer mp_insert_knot (MP mp,pointer q, scaled x, scaled y) {
+ /* returns the inserted knot */
+ pointer r; /* the new knot */
+ r=mp_get_node(mp, knot_node_size);
+ mp_link(r)=mp_link(q); mp_link(q)=r;
+ mp_right_x(r)=mp_right_x(q);
+ mp_right_y(r)=mp_right_y(q);
+ mp_x_coord(r)=x;
+ mp_y_coord(r)=y;
+ mp_right_x(q)=mp_x_coord(q);
+ mp_right_y(q)=mp_y_coord(q);
+ mp_left_x(r)=mp_x_coord(r);
+ mp_left_y(r)=mp_y_coord(r);
+ mp_left_type(r)=mp_explicit;
+ mp_right_type(r)=mp_explicit;
+ mp_originator(r)=mp_program_code;
+ return r;
+}
+
+@ After setting |p:=mp_link(p)|, either |join_type=1| or |q=mp_link(p)|.
+
+@<Set |p=mp_link(p)| and add knots between |p| and |q| as...@>=
+{
+ p=mp_link(p);
+ if ( (join_type==0)||(join_type==3) ) {
+ if ( join_type==0 ) {
+ @<Insert a new knot |r| between |p| and |q| as required for a mitered join@>
+ } else {
+ @<Make |r| the last of two knots inserted between |p| and |q| to form a
+ squared join@>;
+ }
+ if ( r!=null ) {
+ mp_right_x(r)=mp_x_coord(r);
+ mp_right_y(r)=mp_y_coord(r);
+ }
+ }
+}
+
+@ For very small angles, adding a knot is unnecessary and would cause numerical
+problems, so we just set |r:=null| in that case.
+
+@<Insert a new knot |r| between |p| and |q| as required for a mitered join@>=
+{
+ det=mp_take_fraction(mp, dyout,dxin)-mp_take_fraction(mp, dxout,dyin);
+ if ( abs(det)<26844 ) {
+ r=null; /* sine $<10^{-4}$ */
+ } else {
+ tmp=mp_take_fraction(mp, mp_x_coord(q)-mp_x_coord(p),dyout)-
+ mp_take_fraction(mp, mp_y_coord(q)-mp_y_coord(p),dxout);
+ tmp=mp_make_fraction(mp, tmp,det);
+ r=mp_insert_knot(mp, p,mp_x_coord(p)+mp_take_fraction(mp, tmp,dxin),
+ mp_y_coord(p)+mp_take_fraction(mp, tmp,dyin));
+ }
+}
+
+@ @<Other local variables for |make_envelope|@>=
+fraction det; /* a determinant used for mitered join calculations */
+
+@ @<Make |r| the last of two knots inserted between |p| and |q| to form a...@>=
+{
+ ht_x=mp_y_coord(w)-mp_y_coord(w0);
+ ht_y=mp_x_coord(w0)-mp_x_coord(w);
+ while ( (abs(ht_x)<fraction_half)&&(abs(ht_y)<fraction_half) ) {
+ ht_x+=ht_x; ht_y+=ht_y;
+ }
+ @<Scan the pen polygon between |w0| and |w| and make |max_ht| the range dot
+ product with |(ht_x,ht_y)|@>;
+ tmp=mp_make_fraction(mp, max_ht,mp_take_fraction(mp, dxin,ht_x)+
+ mp_take_fraction(mp, dyin,ht_y));
+ r=mp_insert_knot(mp, p,mp_x_coord(p)+mp_take_fraction(mp, tmp,dxin),
+ mp_y_coord(p)+mp_take_fraction(mp, tmp,dyin));
+ tmp=mp_make_fraction(mp, max_ht,mp_take_fraction(mp, dxout,ht_x)+
+ mp_take_fraction(mp, dyout,ht_y));
+ r=mp_insert_knot(mp, r,mp_x_coord(q)+mp_take_fraction(mp, tmp,dxout),
+ mp_y_coord(q)+mp_take_fraction(mp, tmp,dyout));
+}
+
+@ @<Other local variables for |make_envelope|@>=
+fraction ht_x,ht_y; /* perpendicular to the segment from |p| to |q| */
+scaled max_ht; /* maximum height of the pen polygon above the |w0|-|w| line */
+halfword kk; /* keeps track of the pen vertices being scanned */
+pointer ww; /* the pen vertex being tested */
+
+@ The dot product of the vector from |w0| to |ww| with |(ht_x,ht_y)| ranges
+from zero to |max_ht|.
+
+@<Scan the pen polygon between |w0| and |w| and make |max_ht| the range...@>=
+max_ht=0;
+kk=zero_off;
+ww=w;
+while (1) {
+ @<Step |ww| and move |kk| one step closer to |k0|@>;
+ if ( kk==k0 ) break;
+ tmp=mp_take_fraction(mp, (mp_x_coord(ww)-mp_x_coord(w0)),ht_x)+
+ mp_take_fraction(mp, (mp_y_coord(ww)-mp_y_coord(w0)),ht_y);
+ if ( tmp>max_ht ) max_ht=tmp;
+}
+
+
+@ @<Step |ww| and move |kk| one step closer to |k0|@>=
+if ( kk>k0 ) { ww=mp_link(ww); decr(kk); }
+else { ww=knil(ww); incr(kk); }
+
+@ @<If endpoint, double the path |c|, and set |spec_p1| and |spec_p2|@>=
+if ( mp_left_type(c)==mp_endpoint ) {
+ mp->spec_p1=mp_htap_ypoc(mp, c);
+ mp->spec_p2=mp->path_tail;
+ mp_originator(mp->spec_p1)=mp_program_code;
+ mp_link(mp->spec_p2)=mp_link(mp->spec_p1);
+ mp_link(mp->spec_p1)=c;
+ mp_remove_cubic(mp, mp->spec_p1);
+ c=mp->spec_p1;
+ if ( c!=mp_link(c) ) {
+ mp_originator(mp->spec_p2)=mp_program_code;
+ mp_remove_cubic(mp, mp->spec_p2);
+ } else {
+ @<Make |c| look like a cycle of length one@>;
+ }
+}
+
+@ @<Make |c| look like a cycle of length one@>=
+{
+ mp_left_type(c)=mp_explicit; mp_right_type(c)=mp_explicit;
+ mp_left_x(c)=mp_x_coord(c); mp_left_y(c)=mp_y_coord(c);
+ mp_right_x(c)=mp_x_coord(c); mp_right_y(c)=mp_y_coord(c);
+}
+
+@ In degenerate situations we might have to look at the knot preceding~|q|.
+That knot is |p| but if |p<>c|, its coordinates have already been offset by |w|.
+
+@<Set the incoming and outgoing directions at |q|; in case of...@>=
+dxin=mp_x_coord(q)-mp_left_x(q);
+dyin=mp_y_coord(q)-mp_left_y(q);
+if ( (dxin==0)&&(dyin==0) ) {
+ dxin=mp_x_coord(q)-mp_right_x(p);
+ dyin=mp_y_coord(q)-mp_right_y(p);
+ if ( (dxin==0)&&(dyin==0) ) {
+ dxin=mp_x_coord(q)-mp_x_coord(p);
+ dyin=mp_y_coord(q)-mp_y_coord(p);
+ if ( p!=c ) { /* the coordinates of |p| have been offset by |w| */
+ dxin=dxin+mp_x_coord(w);
+ dyin=dyin+mp_y_coord(w);
+ }
+ }
+}
+tmp=mp_pyth_add(mp, dxin,dyin);
+if ( tmp==0 ) {
+ join_type=2;
+} else {
+ dxin=mp_make_fraction(mp, dxin,tmp);
+ dyin=mp_make_fraction(mp, dyin,tmp);
+ @<Set the outgoing direction at |q|@>;
+}
+
+@ If |q=c| then the coordinates of |r| and the control points between |q|
+and~|r| have already been offset by |h|.
+
+@<Set the outgoing direction at |q|@>=
+dxout=mp_right_x(q)-mp_x_coord(q);
+dyout=mp_right_y(q)-mp_y_coord(q);
+if ( (dxout==0)&&(dyout==0) ) {
+ r=mp_link(q);
+ dxout=mp_left_x(r)-mp_x_coord(q);
+ dyout=mp_left_y(r)-mp_y_coord(q);
+ if ( (dxout==0)&&(dyout==0) ) {
+ dxout=mp_x_coord(r)-mp_x_coord(q);
+ dyout=mp_y_coord(r)-mp_y_coord(q);
+ }
+}
+if ( q==c ) {
+ dxout=dxout-mp_x_coord(h);
+ dyout=dyout-mp_y_coord(h);
+}
+tmp=mp_pyth_add(mp, dxout,dyout);
+if ( tmp==0 ) mp_confusion(mp, "degenerate spec");
+@:this can't happen degerate spec}{\quad degenerate spec@>
+dxout=mp_make_fraction(mp, dxout,tmp);
+dyout=mp_make_fraction(mp, dyout,tmp)
+
+@* \[23] Direction and intersection times.
+A path of length $n$ is defined parametrically by functions $x(t)$ and
+$y(t)$, for |0<=t<=n|; we can regard $t$ as the ``time'' at which the path
+reaches the point $\bigl(x(t),y(t)\bigr)$. In this section of the program
+we shall consider operations that determine special times associated with
+given paths: the first time that a path travels in a given direction, and
+a pair of times at which two paths cross each other.
+
+@ Let's start with the easier task. The function |find_direction_time| is
+given a direction |(x,y)| and a path starting at~|h|. If the path never
+travels in direction |(x,y)|, the direction time will be~|-1|; otherwise
+it will be nonnegative.
+
+Certain anomalous cases can arise: If |(x,y)=(0,0)|, so that the given
+direction is undefined, the direction time will be~0. If $\bigl(x'(t),
+y'(t)\bigr)=(0,0)$, so that the path direction is undefined, it will be
+assumed to match any given direction at time~|t|.
+
+The routine solves this problem in nondegenerate cases by rotating the path
+and the given direction so that |(x,y)=(1,0)|; i.e., the main task will be
+to find when a given path first travels ``due east.''
+
+@c
+static scaled mp_find_direction_time (MP mp,scaled x, scaled y, pointer h) {
+ scaled max; /* $\max\bigl(\vert x\vert,\vert y\vert\bigr)$ */
+ pointer p,q; /* for list traversal */
+ scaled n; /* the direction time at knot |p| */
+ scaled tt; /* the direction time within a cubic */
+ @<Other local variables for |find_direction_time|@>;
+ @<Normalize the given direction for better accuracy;
+ but |return| with zero result if it's zero@>;
+ n=0; p=h; phi=0;
+ while (1) {
+ if ( mp_right_type(p)==mp_endpoint ) break;
+ q=mp_link(p);
+ @<Rotate the cubic between |p| and |q|; then
+ |goto found| if the rotated cubic travels due east at some time |tt|;
+ but |break| if an entire cyclic path has been traversed@>;
+ p=q; n=n+unity;
+ }
+ return (-unity);
+FOUND:
+ return (n+tt);
+}
+
+@ @<Normalize the given direction for better accuracy...@>=
+if ( abs(x)<abs(y) ) {
+ x=mp_make_fraction(mp, x,abs(y));
+ if ( y>0 ) y=fraction_one; else y=-fraction_one;
+} else if ( x==0 ) {
+ return 0;
+} else {
+ y=mp_make_fraction(mp, y,abs(x));
+ if ( x>0 ) x=fraction_one; else x=-fraction_one;
+}
+
+@ Since we're interested in the tangent directions, we work with the
+derivative $${1\over3}B'(x_0,x_1,x_2,x_3;t)=
+B(x_1-x_0,x_2-x_1,x_3-x_2;t)$$ instead of
+$B(x_0,x_1,x_2,x_3;t)$ itself. The derived coefficients are also scaled up
+in order to achieve better accuracy.
+
+The given path may turn abruptly at a knot, and it might pass the critical
+tangent direction at such a time. Therefore we remember the direction |phi|
+in which the previous rotated cubic was traveling. (The value of |phi| will be
+undefined on the first cubic, i.e., when |n=0|.)
+
+@<Rotate the cubic between |p| and |q|; then...@>=
+tt=0;
+@<Set local variables |x1,x2,x3| and |y1,y2,y3| to multiples of the control
+ points of the rotated derivatives@>;
+if ( y1==0 ) if ( x1>=0 ) goto FOUND;
+if ( n>0 ) {
+ @<Exit to |found| if an eastward direction occurs at knot |p|@>;
+ if ( p==h ) break;
+ };
+if ( (x3!=0)||(y3!=0) ) phi=mp_n_arg(mp, x3,y3);
+@<Exit to |found| if the curve whose derivatives are specified by
+ |x1,x2,x3,y1,y2,y3| travels eastward at some time~|tt|@>
+
+@ @<Other local variables for |find_direction_time|@>=
+scaled x1,x2,x3,y1,y2,y3; /* multiples of rotated derivatives */
+angle theta,phi; /* angles of exit and entry at a knot */
+fraction t; /* temp storage */
+
+@ @<Set local variables |x1,x2,x3| and |y1,y2,y3| to multiples...@>=
+x1=mp_right_x(p)-mp_x_coord(p); x2=mp_left_x(q)-mp_right_x(p);
+x3=mp_x_coord(q)-mp_left_x(q);
+y1=mp_right_y(p)-mp_y_coord(p); y2=mp_left_y(q)-mp_right_y(p);
+y3=mp_y_coord(q)-mp_left_y(q);
+max=abs(x1);
+if ( abs(x2)>max ) max=abs(x2);
+if ( abs(x3)>max ) max=abs(x3);
+if ( abs(y1)>max ) max=abs(y1);
+if ( abs(y2)>max ) max=abs(y2);
+if ( abs(y3)>max ) max=abs(y3);
+if ( max==0 ) goto FOUND;
+while ( max<fraction_half ){
+ max+=max; x1+=x1; x2+=x2; x3+=x3;
+ y1+=y1; y2+=y2; y3+=y3;
+}
+t=x1; x1=mp_take_fraction(mp, x1,x)+mp_take_fraction(mp, y1,y);
+y1=mp_take_fraction(mp, y1,x)-mp_take_fraction(mp, t,y);
+t=x2; x2=mp_take_fraction(mp, x2,x)+mp_take_fraction(mp, y2,y);
+y2=mp_take_fraction(mp, y2,x)-mp_take_fraction(mp, t,y);
+t=x3; x3=mp_take_fraction(mp, x3,x)+mp_take_fraction(mp, y3,y);
+y3=mp_take_fraction(mp, y3,x)-mp_take_fraction(mp, t,y)
+
+@ @<Exit to |found| if an eastward direction occurs at knot |p|@>=
+theta=mp_n_arg(mp, x1,y1);
+if ( theta>=0 ) if ( phi<=0 ) if ( phi>=theta-one_eighty_deg ) goto FOUND;
+if ( theta<=0 ) if ( phi>=0 ) if ( phi<=theta+one_eighty_deg ) goto FOUND
+
+@ In this step we want to use the |crossing_point| routine to find the
+roots of the quadratic equation $B(y_1,y_2,y_3;t)=0$.
+Several complications arise: If the quadratic equation has a double root,
+the curve never crosses zero, and |crossing_point| will find nothing;
+this case occurs iff $y_1y_3=y_2^2$ and $y_1y_2<0$. If the quadratic
+equation has simple roots, or only one root, we may have to negate it
+so that $B(y_1,y_2,y_3;t)$ crosses from positive to negative at its first root.
+And finally, we need to do special things if $B(y_1,y_2,y_3;t)$ is
+identically zero.
+
+@ @<Exit to |found| if the curve whose derivatives are specified by...@>=
+if ( x1<0 ) if ( x2<0 ) if ( x3<0 ) goto DONE;
+if ( mp_ab_vs_cd(mp, y1,y3,y2,y2)==0 ) {
+ @<Handle the test for eastward directions when $y_1y_3=y_2^2$;
+ either |goto found| or |goto done|@>;
+}
+if ( y1<=0 ) {
+ if ( y1<0 ) { y1=-y1; y2=-y2; y3=-y3; }
+ else if ( y2>0 ){ y2=-y2; y3=-y3; };
+}
+@<Check the places where $B(y_1,y_2,y_3;t)=0$ to see if
+ $B(x_1,x_2,x_3;t)\ge0$@>;
+DONE:
+
+@ The quadratic polynomial $B(y_1,y_2,y_3;t)$ begins |>=0| and has at most
+two roots, because we know that it isn't identically zero.
+
+It must be admitted that the |crossing_point| routine is not perfectly accurate;
+rounding errors might cause it to find a root when $y_1y_3>y_2^2$, or to
+miss the roots when $y_1y_3<y_2^2$. The rotation process is itself
+subject to rounding errors. Yet this code optimistically tries to
+do the right thing.
+
+@d we_found_it { tt=(t+04000) / 010000; goto FOUND; }
+
+@<Check the places where $B(y_1,y_2,y_3;t)=0$...@>=
+t=mp_crossing_point(mp, y1,y2,y3);
+if ( t>fraction_one ) goto DONE;
+y2=t_of_the_way(y2,y3);
+x1=t_of_the_way(x1,x2);
+x2=t_of_the_way(x2,x3);
+x1=t_of_the_way(x1,x2);
+if ( x1>=0 ) we_found_it;
+if ( y2>0 ) y2=0;
+tt=t; t=mp_crossing_point(mp, 0,-y2,-y3);
+if ( t>fraction_one ) goto DONE;
+x1=t_of_the_way(x1,x2);
+x2=t_of_the_way(x2,x3);
+if ( t_of_the_way(x1,x2)>=0 ) {
+ t=t_of_the_way(tt,fraction_one); we_found_it;
+}
+
+@ @<Handle the test for eastward directions when $y_1y_3=y_2^2$;
+ either |goto found| or |goto done|@>=
+{
+ if ( mp_ab_vs_cd(mp, y1,y2,0,0)<0 ) {
+ t=mp_make_fraction(mp, y1,y1-y2);
+ x1=t_of_the_way(x1,x2);
+ x2=t_of_the_way(x2,x3);
+ if ( t_of_the_way(x1,x2)>=0 ) we_found_it;
+ } else if ( y3==0 ) {
+ if ( y1==0 ) {
+ @<Exit to |found| if the derivative $B(x_1,x_2,x_3;t)$ becomes |>=0|@>;
+ } else if ( x3>=0 ) {
+ tt=unity; goto FOUND;
+ }
+ }
+ goto DONE;
+}
+
+@ At this point we know that the derivative of |y(t)| is identically zero,
+and that |x1<0|; but either |x2>=0| or |x3>=0|, so there's some hope of
+traveling east.
+
+@<Exit to |found| if the derivative $B(x_1,x_2,x_3;t)$ becomes |>=0|...@>=
+{
+ t=mp_crossing_point(mp, -x1,-x2,-x3);
+ if ( t<=fraction_one ) we_found_it;
+ if ( mp_ab_vs_cd(mp, x1,x3,x2,x2)<=0 ) {
+ t=mp_make_fraction(mp, x1,x1-x2); we_found_it;
+ }
+}
+
+@ The intersection of two cubics can be found by an interesting variant
+of the general bisection scheme described in the introduction to
+|crossing_point|.\
+Given $w(t)=B(w_0,w_1,w_2,w_3;t)$ and $z(t)=B(z_0,z_1,z_2,z_3;t)$,
+we wish to find a pair of times $(t_1,t_2)$ such that $w(t_1)=z(t_2)$,
+if an intersection exists. First we find the smallest rectangle that
+encloses the points $\{w_0,w_1,w_2,w_3\}$ and check that it overlaps
+the smallest rectangle that encloses
+$\{z_0,z_1,z_2,z_3\}$; if not, the cubics certainly don't intersect.
+But if the rectangles do overlap, we bisect the intervals, getting
+new cubics $w'$ and~$w''$, $z'$~and~$z''$; the intersection routine first
+tries for an intersection between $w'$ and~$z'$, then (if unsuccessful)
+between $w'$ and~$z''$, then (if still unsuccessful) between $w''$ and~$z'$,
+finally (if thrice unsuccessful) between $w''$ and~$z''$. After $l$~successful
+levels of bisection we will have determined the intersection times $t_1$
+and~$t_2$ to $l$~bits of accuracy.
+
+\def\submin{_{\rm min}} \def\submax{_{\rm max}}
+As before, it is better to work with the numbers $W_k=2^l(w_k-w_{k-1})$
+and $Z_k=2^l(z_k-z_{k-1})$ rather than the coefficients $w_k$ and $z_k$
+themselves. We also need one other quantity, $\Delta=2^l(w_0-z_0)$,
+to determine when the enclosing rectangles overlap. Here's why:
+The $x$~coordinates of~$w(t)$ are between $u\submin$ and $u\submax$,
+and the $x$~coordinates of~$z(t)$ are between $x\submin$ and $x\submax$,
+if we write $w_k=(u_k,v_k)$ and $z_k=(x_k,y_k)$ and $u\submin=
+\min(u_0,u_1,u_2,u_3)$, etc. These intervals of $x$~coordinates
+overlap if and only if $u\submin\L x\submax$ and
+$x\submin\L u\submax$. Letting
+$$U\submin=\min(0,U_1,U_1+U_2,U_1+U_2+U_3),\;
+ U\submax=\max(0,U_1,U_1+U_2,U_1+U_2+U_3),$$
+we have $2^lu\submin=2^lu_0+U\submin$, etc.; the condition for overlap
+reduces to
+$$X\submin-U\submax\L 2^l(u_0-x_0)\L X\submax-U\submin.$$
+Thus we want to maintain the quantity $2^l(u_0-x_0)$; similarly,
+the quantity $2^l(v_0-y_0)$ accounts for the $y$~coordinates. The
+coordinates of $\Delta=2^l(w_0-z_0)$ must stay bounded as $l$ increases,
+because of the overlap condition; i.e., we know that $X\submin$,
+$X\submax$, and their relatives are bounded, hence $X\submax-
+U\submin$ and $X\submin-U\submax$ are bounded.
+
+@ Incidentally, if the given cubics intersect more than once, the process
+just sketched will not necessarily find the lexicographically smallest pair
+$(t_1,t_2)$. The solution actually obtained will be smallest in ``shuffled
+order''; i.e., if $t_1=(.a_1a_2\ldots a_{16})_2$ and
+$t_2=(.b_1b_2\ldots b_{16})_2$, then we will minimize
+$a_1b_1a_2b_2\ldots a_{16}b_{16}$, not
+$a_1a_2\ldots a_{16}b_1b_2\ldots b_{16}$.
+Shuffled order agrees with lexicographic order if all pairs of solutions
+$(t_1,t_2)$ and $(t_1',t_2')$ have the property that $t_1<t_1'$ iff
+$t_2<t_2'$; but in general, lexicographic order can be quite different,
+and the bisection algorithm would be substantially less efficient if it were
+constrained by lexicographic order.
+
+For example, suppose that an overlap has been found for $l=3$ and
+$(t_1,t_2)= (.101,.011)$ in binary, but that no overlap is produced by
+either of the alternatives $(.1010,.0110)$, $(.1010,.0111)$ at level~4.
+Then there is probably an intersection in one of the subintervals
+$(.1011,.011x)$; but lexicographic order would require us to explore
+$(.1010,.1xxx)$ and $(.1011,.00xx)$ and $(.1011,.010x)$ first. We wouldn't
+want to store all of the subdivision data for the second path, so the
+subdivisions would have to be regenerated many times. Such inefficiencies
+would be associated with every `1' in the binary representation of~$t_1$.
+
+@ The subdivision process introduces rounding errors, hence we need to
+make a more liberal test for overlap. It is not hard to show that the
+computed values of $U_i$ differ from the truth by at most~$l$, on
+level~$l$, hence $U\submin$ and $U\submax$ will be at most $3l$ in error.
+If $\beta$ is an upper bound on the absolute error in the computed
+components of $\Delta=(|delx|,|dely|)$ on level~$l$, we will replace
+the test `$X\submin-U\submax\L|delx|$' by the more liberal test
+`$X\submin-U\submax\L|delx|+|tol|$', where $|tol|=6l+\beta$.
+
+More accuracy is obtained if we try the algorithm first with |tol=0|;
+the more liberal tolerance is used only if an exact approach fails.
+It is convenient to do this double-take by letting `3' in the preceding
+paragraph be a parameter, which is first 0, then 3.
+
+@<Glob...@>=
+unsigned int tol_step; /* either 0 or 3, usually */
+
+@ We shall use an explicit stack to implement the recursive bisection
+method described above. The |bisect_stack| array will contain numerous 5-word
+packets like $(U_1,U_2,U_3,U\submin,U\submax)$, as well as 20-word packets
+comprising the 5-word packets for $U$, $V$, $X$, and~$Y$.
+
+The following macros define the allocation of stack positions to
+the quantities needed for bisection-intersection.
+
+@d stack_1(A) mp->bisect_stack[(A)] /* $U_1$, $V_1$, $X_1$, or $Y_1$ */
+@d stack_2(A) mp->bisect_stack[(A)+1] /* $U_2$, $V_2$, $X_2$, or $Y_2$ */
+@d stack_3(A) mp->bisect_stack[(A)+2] /* $U_3$, $V_3$, $X_3$, or $Y_3$ */
+@d stack_min(A) mp->bisect_stack[(A)+3]
+ /* $U\submin$, $V\submin$, $X\submin$, or $Y\submin$ */
+@d stack_max(A) mp->bisect_stack[(A)+4]
+ /* $U\submax$, $V\submax$, $X\submax$, or $Y\submax$ */
+@d int_packets 20 /* number of words to represent $U_k$, $V_k$, $X_k$, and $Y_k$ */
+@#
+@d u_packet(A) ((A)-5)
+@d v_packet(A) ((A)-10)
+@d x_packet(A) ((A)-15)
+@d y_packet(A) ((A)-20)
+@d l_packets (mp->bisect_ptr-int_packets)
+@d r_packets mp->bisect_ptr
+@d ul_packet u_packet(l_packets) /* base of $U'_k$ variables */
+@d vl_packet v_packet(l_packets) /* base of $V'_k$ variables */
+@d xl_packet x_packet(l_packets) /* base of $X'_k$ variables */
+@d yl_packet y_packet(l_packets) /* base of $Y'_k$ variables */
+@d ur_packet u_packet(r_packets) /* base of $U''_k$ variables */
+@d vr_packet v_packet(r_packets) /* base of $V''_k$ variables */
+@d xr_packet x_packet(r_packets) /* base of $X''_k$ variables */
+@d yr_packet y_packet(r_packets) /* base of $Y''_k$ variables */
+@#
+@d u1l stack_1(ul_packet) /* $U'_1$ */
+@d u2l stack_2(ul_packet) /* $U'_2$ */
+@d u3l stack_3(ul_packet) /* $U'_3$ */
+@d v1l stack_1(vl_packet) /* $V'_1$ */
+@d v2l stack_2(vl_packet) /* $V'_2$ */
+@d v3l stack_3(vl_packet) /* $V'_3$ */
+@d x1l stack_1(xl_packet) /* $X'_1$ */
+@d x2l stack_2(xl_packet) /* $X'_2$ */
+@d x3l stack_3(xl_packet) /* $X'_3$ */
+@d y1l stack_1(yl_packet) /* $Y'_1$ */
+@d y2l stack_2(yl_packet) /* $Y'_2$ */
+@d y3l stack_3(yl_packet) /* $Y'_3$ */
+@d u1r stack_1(ur_packet) /* $U''_1$ */
+@d u2r stack_2(ur_packet) /* $U''_2$ */
+@d u3r stack_3(ur_packet) /* $U''_3$ */
+@d v1r stack_1(vr_packet) /* $V''_1$ */
+@d v2r stack_2(vr_packet) /* $V''_2$ */
+@d v3r stack_3(vr_packet) /* $V''_3$ */
+@d x1r stack_1(xr_packet) /* $X''_1$ */
+@d x2r stack_2(xr_packet) /* $X''_2$ */
+@d x3r stack_3(xr_packet) /* $X''_3$ */
+@d y1r stack_1(yr_packet) /* $Y''_1$ */
+@d y2r stack_2(yr_packet) /* $Y''_2$ */
+@d y3r stack_3(yr_packet) /* $Y''_3$ */
+@#
+@d stack_dx mp->bisect_stack[mp->bisect_ptr] /* stacked value of |delx| */
+@d stack_dy mp->bisect_stack[mp->bisect_ptr+1] /* stacked value of |dely| */
+@d stack_tol mp->bisect_stack[mp->bisect_ptr+2] /* stacked value of |tol| */
+@d stack_uv mp->bisect_stack[mp->bisect_ptr+3] /* stacked value of |uv| */
+@d stack_xy mp->bisect_stack[mp->bisect_ptr+4] /* stacked value of |xy| */
+@d int_increment (int_packets+int_packets+5) /* number of stack words per level */
+
+@<Glob...@>=
+integer *bisect_stack;
+integer bisect_ptr;
+
+@ @<Allocate or initialize ...@>=
+mp->bisect_stack = xmalloc((bistack_size+1),sizeof(integer));
+
+@ @<Dealloc variables@>=
+xfree(mp->bisect_stack);
+
+@ @<Check the ``constant''...@>=
+if ( int_packets+17*int_increment>bistack_size ) mp->bad=19;
+
+@ Computation of the min and max is a tedious but fairly fast sequence of
+instructions; exactly four comparisons are made in each branch.
+
+@d set_min_max(A)
+ if ( stack_1((A))<0 ) {
+ if ( stack_3((A))>=0 ) {
+ if ( stack_2((A))<0 ) stack_min((A))=stack_1((A))+stack_2((A));
+ else stack_min((A))=stack_1((A));
+ stack_max((A))=stack_1((A))+stack_2((A))+stack_3((A));
+ if ( stack_max((A))<0 ) stack_max((A))=0;
+ } else {
+ stack_min((A))=stack_1((A))+stack_2((A))+stack_3((A));
+ if ( stack_min((A))>stack_1((A)) ) stack_min((A))=stack_1((A));
+ stack_max((A))=stack_1((A))+stack_2((A));
+ if ( stack_max((A))<0 ) stack_max((A))=0;
+ }
+ } else if ( stack_3((A))<=0 ) {
+ if ( stack_2((A))>0 ) stack_max((A))=stack_1((A))+stack_2((A));
+ else stack_max((A))=stack_1((A));
+ stack_min((A))=stack_1((A))+stack_2((A))+stack_3((A));
+ if ( stack_min((A))>0 ) stack_min((A))=0;
+ } else {
+ stack_max((A))=stack_1((A))+stack_2((A))+stack_3((A));
+ if ( stack_max((A))<stack_1((A)) ) stack_max((A))=stack_1((A));
+ stack_min((A))=stack_1((A))+stack_2((A));
+ if ( stack_min((A))>0 ) stack_min((A))=0;
+ }
+
+@ It's convenient to keep the current values of $l$, $t_1$, and $t_2$ in
+the integer form $2^l+2^lt_1$ and $2^l+2^lt_2$. The |cubic_intersection|
+routine uses global variables |cur_t| and |cur_tt| for this purpose;
+after successful completion, |cur_t| and |cur_tt| will contain |unity|
+plus the |scaled| values of $t_1$ and~$t_2$.
+
+The values of |cur_t| and |cur_tt| will be set to zero if |cubic_intersection|
+finds no intersection. The routine gives up and gives an approximate answer
+if it has backtracked
+more than 5000 times (otherwise there are cases where several minutes
+of fruitless computation would be possible).
+
+@d max_patience 5000
+
+@<Glob...@>=
+integer cur_t;integer cur_tt; /* controls and results of |cubic_intersection| */
+integer time_to_go; /* this many backtracks before giving up */
+integer max_t; /* maximum of $2^{l+1}$ so far achieved */
+
+@ The given cubics $B(w_0,w_1,w_2,w_3;t)$ and
+$B(z_0,z_1,z_2,z_3;t)$ are specified in adjacent knot nodes |(p,mp_link(p))|
+and |(pp,mp_link(pp))|, respectively.
+
+@c
+static void mp_cubic_intersection (MP mp,pointer p, pointer pp) {
+ pointer q,qq; /* |mp_link(p)|, |mp_link(pp)| */
+ mp->time_to_go=max_patience; mp->max_t=2;
+ @<Initialize for intersections at level zero@>;
+CONTINUE:
+ while (1) {
+ if ( mp->delx-mp->tol<=stack_max(x_packet(mp->xy))-stack_min(u_packet(mp->uv)))
+ if ( mp->delx+mp->tol>=stack_min(x_packet(mp->xy))-stack_max(u_packet(mp->uv)))
+ if ( mp->dely-mp->tol<=stack_max(y_packet(mp->xy))-stack_min(v_packet(mp->uv)))
+ if ( mp->dely+mp->tol>=stack_min(y_packet(mp->xy))-stack_max(v_packet(mp->uv)))
+ {
+ if ( mp->cur_t>=mp->max_t ){
+ if ( mp->max_t==two ) { /* we've done 17 bisections */
+ mp->cur_t=halfp(mp->cur_t+1);
+ mp->cur_tt=halfp(mp->cur_tt+1);
+ return;
+ }
+ mp->max_t+=mp->max_t; mp->appr_t=mp->cur_t; mp->appr_tt=mp->cur_tt;
+ }
+ @<Subdivide for a new level of intersection@>;
+ goto CONTINUE;
+ }
+ if ( mp->time_to_go>0 ) {
+ decr(mp->time_to_go);
+ } else {
+ while ( mp->appr_t<unity ) {
+ mp->appr_t+=mp->appr_t; mp->appr_tt+=mp->appr_tt;
+ }
+ mp->cur_t=mp->appr_t; mp->cur_tt=mp->appr_tt; return;
+ }
+ @<Advance to the next pair |(cur_t,cur_tt)|@>;
+ }
+}
+
+@ The following variables are global, although they are used only by
+|cubic_intersection|, because it is necessary on some machines to
+split |cubic_intersection| up into two procedures.
+
+@<Glob...@>=
+integer delx;integer dely; /* the components of $\Delta=2^l(w_0-z_0)$ */
+integer tol; /* bound on the uncertainty in the overlap test */
+integer uv;
+integer xy; /* pointers to the current packets of interest */
+integer three_l; /* |tol_step| times the bisection level */
+integer appr_t;integer appr_tt; /* best approximations known to the answers */
+
+@ We shall assume that the coordinates are sufficiently non-extreme that
+integer overflow will not occur.
+@^overflow in arithmetic@>
+
+@<Initialize for intersections at level zero@>=
+q=mp_link(p); qq=mp_link(pp); mp->bisect_ptr=int_packets;
+u1r=mp_right_x(p)-mp_x_coord(p); u2r=mp_left_x(q)-mp_right_x(p);
+u3r=mp_x_coord(q)-mp_left_x(q); set_min_max(ur_packet);
+v1r=mp_right_y(p)-mp_y_coord(p); v2r=mp_left_y(q)-mp_right_y(p);
+v3r=mp_y_coord(q)-mp_left_y(q); set_min_max(vr_packet);
+x1r=mp_right_x(pp)-mp_x_coord(pp); x2r=mp_left_x(qq)-mp_right_x(pp);
+x3r=mp_x_coord(qq)-mp_left_x(qq); set_min_max(xr_packet);
+y1r=mp_right_y(pp)-mp_y_coord(pp); y2r=mp_left_y(qq)-mp_right_y(pp);
+y3r=mp_y_coord(qq)-mp_left_y(qq); set_min_max(yr_packet);
+mp->delx=mp_x_coord(p)-mp_x_coord(pp); mp->dely=mp_y_coord(p)-mp_y_coord(pp);
+mp->tol=0; mp->uv=r_packets; mp->xy=r_packets;
+mp->three_l=0; mp->cur_t=1; mp->cur_tt=1
+
+@ @<Subdivide for a new level of intersection@>=
+stack_dx=mp->delx; stack_dy=mp->dely; stack_tol=mp->tol;
+stack_uv=mp->uv; stack_xy=mp->xy;
+mp->bisect_ptr=mp->bisect_ptr+int_increment;
+mp->cur_t+=mp->cur_t; mp->cur_tt+=mp->cur_tt;
+u1l=stack_1(u_packet(mp->uv)); u3r=stack_3(u_packet(mp->uv));
+u2l=half(u1l+stack_2(u_packet(mp->uv)));
+u2r=half(u3r+stack_2(u_packet(mp->uv)));
+u3l=half(u2l+u2r); u1r=u3l;
+set_min_max(ul_packet); set_min_max(ur_packet);
+v1l=stack_1(v_packet(mp->uv)); v3r=stack_3(v_packet(mp->uv));
+v2l=half(v1l+stack_2(v_packet(mp->uv)));
+v2r=half(v3r+stack_2(v_packet(mp->uv)));
+v3l=half(v2l+v2r); v1r=v3l;
+set_min_max(vl_packet); set_min_max(vr_packet);
+x1l=stack_1(x_packet(mp->xy)); x3r=stack_3(x_packet(mp->xy));
+x2l=half(x1l+stack_2(x_packet(mp->xy)));
+x2r=half(x3r+stack_2(x_packet(mp->xy)));
+x3l=half(x2l+x2r); x1r=x3l;
+set_min_max(xl_packet); set_min_max(xr_packet);
+y1l=stack_1(y_packet(mp->xy)); y3r=stack_3(y_packet(mp->xy));
+y2l=half(y1l+stack_2(y_packet(mp->xy)));
+y2r=half(y3r+stack_2(y_packet(mp->xy)));
+y3l=half(y2l+y2r); y1r=y3l;
+set_min_max(yl_packet); set_min_max(yr_packet);
+mp->uv=l_packets; mp->xy=l_packets;
+mp->delx+=mp->delx; mp->dely+=mp->dely;
+mp->tol=mp->tol-mp->three_l+mp->tol_step;
+mp->tol+=mp->tol; mp->three_l=mp->three_l+mp->tol_step
+
+@ @<Advance to the next pair |(cur_t,cur_tt)|@>=
+NOT_FOUND:
+if ( odd(mp->cur_tt) ) {
+ if ( odd(mp->cur_t) ) {
+ @<Descend to the previous level and |goto not_found|@>;
+ } else {
+ incr(mp->cur_t);
+ mp->delx=mp->delx+stack_1(u_packet(mp->uv))+stack_2(u_packet(mp->uv))
+ +stack_3(u_packet(mp->uv));
+ mp->dely=mp->dely+stack_1(v_packet(mp->uv))+stack_2(v_packet(mp->uv))
+ +stack_3(v_packet(mp->uv));
+ mp->uv=mp->uv+int_packets; /* switch from |l_packets| to |r_packets| */
+ decr(mp->cur_tt); mp->xy=mp->xy-int_packets;
+ /* switch from |r_packets| to |l_packets| */
+ mp->delx=mp->delx+stack_1(x_packet(mp->xy))+stack_2(x_packet(mp->xy))
+ +stack_3(x_packet(mp->xy));
+ mp->dely=mp->dely+stack_1(y_packet(mp->xy))+stack_2(y_packet(mp->xy))
+ +stack_3(y_packet(mp->xy));
+ }
+} else {
+ incr(mp->cur_tt); mp->tol=mp->tol+mp->three_l;
+ mp->delx=mp->delx-stack_1(x_packet(mp->xy))-stack_2(x_packet(mp->xy))
+ -stack_3(x_packet(mp->xy));
+ mp->dely=mp->dely-stack_1(y_packet(mp->xy))-stack_2(y_packet(mp->xy))
+ -stack_3(y_packet(mp->xy));
+ mp->xy=mp->xy+int_packets; /* switch from |l_packets| to |r_packets| */
+}
+
+@ @<Descend to the previous level...@>=
+{
+ mp->cur_t=halfp(mp->cur_t); mp->cur_tt=halfp(mp->cur_tt);
+ if ( mp->cur_t==0 ) return;
+ mp->bisect_ptr=mp->bisect_ptr-int_increment;
+ mp->three_l=mp->three_l-mp->tol_step;
+ mp->delx=stack_dx; mp->dely=stack_dy; mp->tol=stack_tol;
+ mp->uv=stack_uv; mp->xy=stack_xy;
+ goto NOT_FOUND;
+}
+
+@ The |path_intersection| procedure is much simpler.
+It invokes |cubic_intersection| in lexicographic order until finding a
+pair of cubics that intersect. The final intersection times are placed in
+|cur_t| and~|cur_tt|.
+
+@c
+static void mp_path_intersection (MP mp,pointer h, pointer hh) {
+ pointer p,pp; /* link registers that traverse the given paths */
+ integer n,nn; /* integer parts of intersection times, minus |unity| */
+ @<Change one-point paths into dead cycles@>;
+ mp->tol_step=0;
+ do {
+ n=-unity; p=h;
+ do {
+ if ( mp_right_type(p)!=mp_endpoint ) {
+ nn=-unity; pp=hh;
+ do {
+ if ( mp_right_type(pp)!=mp_endpoint ) {
+ mp_cubic_intersection(mp, p,pp);
+ if ( mp->cur_t>0 ) {
+ mp->cur_t=mp->cur_t+n; mp->cur_tt=mp->cur_tt+nn;
+ return;
+ }
+ }
+ nn=nn+unity; pp=mp_link(pp);
+ } while (pp!=hh);
+ }
+ n=n+unity; p=mp_link(p);
+ } while (p!=h);
+ mp->tol_step=mp->tol_step+3;
+ } while (mp->tol_step<=3);
+ mp->cur_t=-unity; mp->cur_tt=-unity;
+}
+
+@ @<Change one-point paths...@>=
+if ( mp_right_type(h)==mp_endpoint ) {
+ mp_right_x(h)=mp_x_coord(h); mp_left_x(h)=mp_x_coord(h);
+ mp_right_y(h)=mp_y_coord(h); mp_left_y(h)=mp_y_coord(h); mp_right_type(h)=mp_explicit;
+}
+if ( mp_right_type(hh)==mp_endpoint ) {
+ mp_right_x(hh)=mp_x_coord(hh); mp_left_x(hh)=mp_x_coord(hh);
+ mp_right_y(hh)=mp_y_coord(hh); mp_left_y(hh)=mp_y_coord(hh); mp_right_type(hh)=mp_explicit;
+}
+
+@* \[24] Dynamic linear equations.
+\MP\ users define variables implicitly by stating equations that should be
+satisfied; the computer is supposed to be smart enough to solve those equations.
+And indeed, the computer tries valiantly to do so, by distinguishing five
+different types of numeric values:
+
+\smallskip\hang
+|type(p)=mp_known| is the nice case, when |value(p)| is the |scaled| value
+of the variable whose address is~|p|.
+
+\smallskip\hang
+|type(p)=mp_dependent| means that |value(p)| is not present, but |dep_list(p)|
+points to a {\sl dependency list\/} that expresses the value of variable~|p|
+as a |scaled| number plus a sum of independent variables with |fraction|
+coefficients.
+
+\smallskip\hang
+|type(p)=mp_independent| means that |value(p)=64s+m|, where |s>0| is a ``serial
+number'' reflecting the time this variable was first used in an equation;
+also |0<=m<64|, and each dependent variable
+that refers to this one is actually referring to the future value of
+this variable times~$2^m$. (Usually |m=0|, but higher degrees of
+scaling are sometimes needed to keep the coefficients in dependency lists
+from getting too large. The value of~|m| will always be even.)
+
+\smallskip\hang
+|type(p)=mp_numeric_type| means that variable |p| hasn't appeared in an
+equation before, but it has been explicitly declared to be numeric.
+
+\smallskip\hang
+|type(p)=undefined| means that variable |p| hasn't appeared before.
+
+\smallskip\noindent
+We have actually discussed these five types in the reverse order of their
+history during a computation: Once |known|, a variable never again
+becomes |dependent|; once |dependent|, it almost never again becomes
+|mp_independent|; once |mp_independent|, it never again becomes |mp_numeric_type|;
+and once |mp_numeric_type|, it never again becomes |undefined| (except
+of course when the user specifically decides to scrap the old value
+and start again). A backward step may, however, take place: Sometimes
+a |dependent| variable becomes |mp_independent| again, when one of the
+independent variables it depends on is reverting to |undefined|.
+
+
+The next patch detects overflow of independent-variable serial
+numbers. Diagnosed and patched by Thorsten Dahlheimer.
+
+@d s_scale 64 /* the serial numbers are multiplied by this factor */
+@d new_indep(A) /* create a new independent variable */
+ { if ( mp->serial_no>el_gordo-s_scale )
+ mp_fatal_error(mp, "variable instance identifiers exhausted");
+ mp_type((A))=mp_independent; mp->serial_no=mp->serial_no+s_scale;
+ value((A))=mp->serial_no;
+ }
+
+@<Glob...@>=
+integer serial_no; /* the most recent serial number, times |s_scale| */
+
+@ @<Make variable |q+s| newly independent@>=new_indep(q+s)
+
+@ But how are dependency lists represented? It's simple: The linear combination
+$\alpha_1v_1+\cdots+\alpha_kv_k+\beta$ appears in |k+1| value nodes. If
+|q=dep_list(p)| points to this list, and if |k>0|, then |value(q)=
+@t$\alpha_1$@>| (which is a |fraction|); |mp_info(q)| points to the location
+of $\alpha_1$; and |mp_link(p)| points to the dependency list
+$\alpha_2v_2+\cdots+\alpha_kv_k+\beta$. On the other hand if |k=0|,
+then |value(q)=@t$\beta$@>| (which is |scaled|) and |mp_info(q)=null|.
+The independent variables $v_1$, \dots,~$v_k$ have been sorted so that
+they appear in decreasing order of their |value| fields (i.e., of
+their serial numbers). \ (It is convenient to use decreasing order,
+since |value(null)=0|. If the independent variables were not sorted by
+serial number but by some other criterion, such as their location in |mem|,
+the equation-solving mechanism would be too system-dependent, because
+the ordering can affect the computed results.)
+
+The |link| field in the node that contains the constant term $\beta$ is
+called the {\sl final link\/} of the dependency list. \MP\ maintains
+a doubly-linked master list of all dependency lists, in terms of a permanently
+allocated node
+in |mem| called |dep_head|. If there are no dependencies, we have
+|mp_link(dep_head)=dep_head| and |prev_dep(dep_head)=dep_head|;
+otherwise |mp_link(dep_head)| points to the first dependent variable, say~|p|,
+and |prev_dep(p)=dep_head|. We have |type(p)=mp_dependent|, and |dep_list(p)|
+points to its dependency list. If the final link of that dependency list
+occurs in location~|q|, then |mp_link(q)| points to the next dependent
+variable (say~|r|); and we have |prev_dep(r)=q|, etc.
+
+@d dep_list(A) mp_link(value_loc((A)))
+ /* half of the |value| field in a |dependent| variable */
+@d prev_dep(A) mp_info(value_loc((A)))
+ /* the other half; makes a doubly linked list */
+@d dep_node_size 2 /* the number of words per dependency node */
+
+@<Initialize table entries...@>= mp->serial_no=0;
+mp_link(dep_head)=dep_head; prev_dep(dep_head)=dep_head;
+mp_info(dep_head)=null; dep_list(dep_head)=null;
+
+@ Actually the description above contains a little white lie. There's
+another kind of variable called |mp_proto_dependent|, which is
+just like a |dependent| one except that the $\alpha$ coefficients
+in its dependency list are |scaled| instead of being fractions.
+Proto-dependency lists are mixed with dependency lists in the
+nodes reachable from |dep_head|.
+
+@ Here is a procedure that prints a dependency list in symbolic form.
+The second parameter should be either |dependent| or |mp_proto_dependent|,
+to indicate the scaling of the coefficients.
+
+@<Declarations@>=
+static void mp_print_dependency (MP mp,pointer p, quarterword t);
+
+@ @c
+void mp_print_dependency (MP mp,pointer p, quarterword t) {
+ integer v; /* a coefficient */
+ pointer pp,q; /* for list manipulation */
+ pp=p;
+ while (true) {
+ v=abs(value(p)); q=mp_info(p);
+ if ( q==null ) { /* the constant term */
+ if ( (v!=0)||(p==pp) ) {
+ if ( value(p)>0 ) if ( p!=pp ) mp_print_char(mp, xord('+'));
+ mp_print_scaled(mp, value(p));
+ }
+ return;
+ }
+ @<Print the coefficient, unless it's $\pm1.0$@>;
+ if ( mp_type(q)!=mp_independent ) mp_confusion(mp, "dep");
+@:this can't happen dep}{\quad dep@>
+ mp_print_variable_name(mp, q); v=value(q) % s_scale;
+ while ( v>0 ) { mp_print(mp, "*4"); v=v-2; }
+ p=mp_link(p);
+ }
+}
+
+@ @<Print the coefficient, unless it's $\pm1.0$@>=
+if ( value(p)<0 ) mp_print_char(mp, xord('-'));
+else if ( p!=pp ) mp_print_char(mp, xord('+'));
+if ( t==mp_dependent ) v=mp_round_fraction(mp, v);
+if ( v!=unity ) mp_print_scaled(mp, v)
+
+@ The maximum absolute value of a coefficient in a given dependency list
+is returned by the following simple function.
+
+@c
+static fraction mp_max_coef (MP mp,pointer p) {
+ fraction x; /* the maximum so far */
+ x=0;
+ while ( mp_info(p)!=null ) {
+ if ( abs(value(p))>x ) x=abs(value(p));
+ p=mp_link(p);
+ }
+ return x;
+}
+
+@ One of the main operations needed on dependency lists is to add a multiple
+of one list to the other; we call this |p_plus_fq|, where |p| and~|q| point
+to dependency lists and |f| is a fraction.
+
+If the coefficient of any independent variable becomes |coef_bound| or
+more, in absolute value, this procedure changes the type of that variable
+to `|independent_needing_fix|', and sets the global variable |fix_needed|
+to~|true|. The value of $|coef_bound|=\mu$ is chosen so that
+$\mu^2+\mu<8$; this means that the numbers we deal with won't
+get too large. (Instead of the ``optimum'' $\mu=(\sqrt{33}-1)/2\approx
+2.3723$, the safer value 7/3 is taken as the threshold.)
+
+The changes mentioned in the preceding paragraph are actually done only if
+the global variable |watch_coefs| is |true|. But it usually is; in fact,
+it is |false| only when \MP\ is making a dependency list that will soon
+be equated to zero.
+
+Several procedures that act on dependency lists, including |p_plus_fq|,
+set the global variable |dep_final| to the final (constant term) node of
+the dependency list that they produce.
+
+@d coef_bound 04525252525 /* |fraction| approximation to 7/3 */
+@d independent_needing_fix 0
+
+@<Glob...@>=
+boolean fix_needed; /* does at least one |independent| variable need scaling? */
+boolean watch_coefs; /* should we scale coefficients that exceed |coef_bound|? */
+pointer dep_final; /* location of the constant term and final link */
+
+@ @<Set init...@>=
+mp->fix_needed=false; mp->watch_coefs=true;
+
+@ The |p_plus_fq| procedure has a fourth parameter, |t|, that should be
+set to |mp_proto_dependent| if |p| is a proto-dependency list. In this
+case |f| will be |scaled|, not a |fraction|. Similarly, the fifth parameter~|tt|
+should be |mp_proto_dependent| if |q| is a proto-dependency list.
+
+List |q| is unchanged by the operation; but list |p| is totally destroyed.
+
+The final link of the dependency list or proto-dependency list returned
+by |p_plus_fq| is the same as the original final link of~|p|. Indeed, the
+constant term of the result will be located in the same |mem| location
+as the original constant term of~|p|.
+
+Coefficients of the result are assumed to be zero if they are less than
+a certain threshold. This compensates for inevitable rounding errors,
+and tends to make more variables `|known|'. The threshold is approximately
+$10^{-5}$ in the case of normal dependency lists, $10^{-4}$ for
+proto-dependencies.
+
+@d fraction_threshold 2685 /* a |fraction| coefficient less than this is zeroed */
+@d half_fraction_threshold 1342 /* half of |fraction_threshold| */
+@d scaled_threshold 8 /* a |scaled| coefficient less than this is zeroed */
+@d half_scaled_threshold 4 /* half of |scaled_threshold| */
+
+@<Declarations@>=
+static pointer mp_p_plus_fq ( MP mp, pointer p, integer f,
+ pointer q, quarterword t, quarterword tt) ;
+
+@ @c
+pointer mp_p_plus_fq ( MP mp, pointer p, integer f,
+ pointer q, quarterword t, quarterword tt) {
+ pointer pp,qq; /* |mp_info(p)| and |mp_info(q)|, respectively */
+ pointer r,s; /* for list manipulation */
+ integer threshold; /* defines a neighborhood of zero */
+ integer v; /* temporary register */
+ if ( t==mp_dependent ) threshold=fraction_threshold;
+ else threshold=scaled_threshold;
+ r=temp_head; pp=mp_info(p); qq=mp_info(q);
+ while (1) {
+ if ( pp==qq ) {
+ if ( pp==null ) {
+ break;
+ } else {
+ @<Contribute a term from |p|, plus |f| times the
+ corresponding term from |q|@>
+ }
+ } else if ( value(pp)<value(qq) ) {
+ @<Contribute a term from |q|, multiplied by~|f|@>
+ } else {
+ mp_link(r)=p; r=p; p=mp_link(p); pp=mp_info(p);
+ }
+ }
+ if ( t==mp_dependent )
+ value(p)=mp_slow_add(mp, value(p),mp_take_fraction(mp, value(q),f));
+ else
+ value(p)=mp_slow_add(mp, value(p),mp_take_scaled(mp, value(q),f));
+ mp_link(r)=p; mp->dep_final=p;
+ return mp_link(temp_head);
+}
+
+@ @<Contribute a term from |p|, plus |f|...@>=
+{
+ if ( tt==mp_dependent ) v=value(p)+mp_take_fraction(mp, f,value(q));
+ else v=value(p)+mp_take_scaled(mp, f,value(q));
+ value(p)=v; s=p; p=mp_link(p);
+ if ( abs(v)<threshold ) {
+ mp_free_node(mp, s,dep_node_size);
+ } else {
+ if ( (abs(v)>=coef_bound) && mp->watch_coefs ) {
+ mp_type(qq)=independent_needing_fix; mp->fix_needed=true;
+ }
+ mp_link(r)=s; r=s;
+ };
+ pp=mp_info(p); q=mp_link(q); qq=mp_info(q);
+}
+
+@ @<Contribute a term from |q|, multiplied by~|f|@>=
+{
+ if ( tt==mp_dependent ) v=mp_take_fraction(mp, f,value(q));
+ else v=mp_take_scaled(mp, f,value(q));
+ if ( abs(v)>halfp(threshold) ) {
+ s=mp_get_node(mp, dep_node_size); mp_info(s)=qq; value(s)=v;
+ if ( (abs(v)>=coef_bound) && mp->watch_coefs ) {
+ mp_type(qq)=independent_needing_fix; mp->fix_needed=true;
+ }
+ mp_link(r)=s; r=s;
+ }
+ q=mp_link(q); qq=mp_info(q);
+}
+
+@ It is convenient to have another subroutine for the special case
+of |p_plus_fq| when |f=1.0|. In this routine lists |p| and |q| are
+both of the same type~|t| (either |dependent| or |mp_proto_dependent|).
+
+@c
+static pointer mp_p_plus_q (MP mp,pointer p, pointer q, quarterword t) {
+ pointer pp,qq; /* |mp_info(p)| and |mp_info(q)|, respectively */
+ pointer r,s; /* for list manipulation */
+ integer threshold; /* defines a neighborhood of zero */
+ integer v; /* temporary register */
+ if ( t==mp_dependent ) threshold=fraction_threshold;
+ else threshold=scaled_threshold;
+ r=temp_head; pp=mp_info(p); qq=mp_info(q);
+ while (1) {
+ if ( pp==qq ) {
+ if ( pp==null ) {
+ break;
+ } else {
+ @<Contribute a term from |p|, plus the
+ corresponding term from |q|@>
+ }
+ } else {
+ if ( value(pp)<value(qq) ) {
+ s=mp_get_node(mp, dep_node_size); mp_info(s)=qq; value(s)=value(q);
+ q=mp_link(q); qq=mp_info(q); mp_link(r)=s; r=s;
+ } else {
+ mp_link(r)=p; r=p; p=mp_link(p); pp=mp_info(p);
+ }
+ }
+ }
+ value(p)=mp_slow_add(mp, value(p),value(q));
+ mp_link(r)=p; mp->dep_final=p;
+ return mp_link(temp_head);
+}
+
+@ @<Contribute a term from |p|, plus the...@>=
+{
+ v=value(p)+value(q);
+ value(p)=v; s=p; p=mp_link(p); pp=mp_info(p);
+ if ( abs(v)<threshold ) {
+ mp_free_node(mp, s,dep_node_size);
+ } else {
+ if ( (abs(v)>=coef_bound ) && mp->watch_coefs ) {
+ mp_type(qq)=independent_needing_fix; mp->fix_needed=true;
+ }
+ mp_link(r)=s; r=s;
+ }
+ q=mp_link(q); qq=mp_info(q);
+}
+
+@ A somewhat simpler routine will multiply a dependency list
+by a given constant~|v|. The constant is either a |fraction| less than
+|fraction_one|, or it is |scaled|. In the latter case we might be forced to
+convert a dependency list to a proto-dependency list.
+Parameters |t0| and |t1| are the list types before and after;
+they should agree unless |t0=mp_dependent| and |t1=mp_proto_dependent|
+and |v_is_scaled=true|.
+
+@c
+static pointer mp_p_times_v (MP mp,pointer p, integer v, quarterword t0,
+ quarterword t1, boolean v_is_scaled) {
+ pointer r,s; /* for list manipulation */
+ integer w; /* tentative coefficient */
+ integer threshold;
+ boolean scaling_down;
+ if ( t0!=t1 ) scaling_down=true; else scaling_down=(!v_is_scaled);
+ if ( t1==mp_dependent ) threshold=half_fraction_threshold;
+ else threshold=half_scaled_threshold;
+ r=temp_head;
+ while ( mp_info(p)!=null ) {
+ if ( scaling_down ) w=mp_take_fraction(mp, v,value(p));
+ else w=mp_take_scaled(mp, v,value(p));
+ if ( abs(w)<=threshold ) {
+ s=mp_link(p); mp_free_node(mp, p,dep_node_size); p=s;
+ } else {
+ if ( abs(w)>=coef_bound ) {
+ mp->fix_needed=true; mp_type(mp_info(p))=independent_needing_fix;
+ }
+ mp_link(r)=p; r=p; value(p)=w; p=mp_link(p);
+ }
+ }
+ mp_link(r)=p;
+ if ( v_is_scaled ) value(p)=mp_take_scaled(mp, value(p),v);
+ else value(p)=mp_take_fraction(mp, value(p),v);
+ return mp_link(temp_head);
+}
+
+@ Similarly, we sometimes need to divide a dependency list
+by a given |scaled| constant.
+
+@<Declarations@>=
+static pointer mp_p_over_v (MP mp,pointer p, scaled v, quarterword
+ t0, quarterword t1) ;
+
+@ @c
+pointer mp_p_over_v (MP mp,pointer p, scaled v, quarterword
+ t0, quarterword t1) {
+ pointer r,s; /* for list manipulation */
+ integer w; /* tentative coefficient */
+ integer threshold;
+ boolean scaling_down;
+ if ( t0!=t1 ) scaling_down=true; else scaling_down=false;
+ if ( t1==mp_dependent ) threshold=half_fraction_threshold;
+ else threshold=half_scaled_threshold;
+ r=temp_head;
+ while ( mp_info( p)!=null ) {
+ if ( scaling_down ) {
+ if ( abs(v)<02000000 ) w=mp_make_scaled(mp, value(p),v*010000);
+ else w=mp_make_scaled(mp, mp_round_fraction(mp, value(p)),v);
+ } else {
+ w=mp_make_scaled(mp, value(p),v);
+ }
+ if ( abs(w)<=threshold ) {
+ s=mp_link(p); mp_free_node(mp, p,dep_node_size); p=s;
+ } else {
+ if ( abs(w)>=coef_bound ) {
+ mp->fix_needed=true; mp_type(mp_info(p))=independent_needing_fix;
+ }
+ mp_link(r)=p; r=p; value(p)=w; p=mp_link(p);
+ }
+ }
+ mp_link(r)=p; value(p)=mp_make_scaled(mp, value(p),v);
+ return mp_link(temp_head);
+}
+
+@ Here's another utility routine for dependency lists. When an independent
+variable becomes dependent, we want to remove it from all existing
+dependencies. The |p_with_x_becoming_q| function computes the
+dependency list of~|p| after variable~|x| has been replaced by~|q|.
+
+This procedure has basically the same calling conventions as |p_plus_fq|:
+List~|q| is unchanged; list~|p| is destroyed; the constant node and the
+final link are inherited from~|p|; and the fourth parameter tells whether
+or not |p| is |mp_proto_dependent|. However, the global variable |dep_final|
+is not altered if |x| does not occur in list~|p|.
+
+@c
+static pointer mp_p_with_x_becoming_q (MP mp,pointer p,
+ pointer x, pointer q, quarterword t) {
+ pointer r,s; /* for list manipulation */
+ integer v; /* coefficient of |x| */
+ integer sx; /* serial number of |x| */
+ s=p; r=temp_head; sx=value(x);
+ while ( value(mp_info(s))>sx ) { r=s; s=mp_link(s); };
+ if ( mp_info(s)!=x ) {
+ return p;
+ } else {
+ mp_link(temp_head)=p; mp_link(r)=mp_link(s); v=value(s);
+ mp_free_node(mp, s,dep_node_size);
+ return mp_p_plus_fq(mp, mp_link(temp_head),v,q,t,mp_dependent);
+ }
+}
+
+@ Here's a simple procedure that reports an error when a variable
+has just received a known value that's out of the required range.
+
+@<Declarations@>=
+static void mp_val_too_big (MP mp,scaled x) ;
+
+@ @c void mp_val_too_big (MP mp,scaled x) {
+ if ( mp->internal[mp_warning_check]>0 ) {
+ print_err("Value is too large ("); mp_print_scaled(mp, x); mp_print_char(mp, xord(')'));
+@.Value is too large@>
+ help4("The equation I just processed has given some variable",
+ "a value of 4096 or more. Continue and I'll try to cope",
+ "with that big value; but it might be dangerous.",
+ "(Set warningcheck:=0 to suppress this message.)");
+ mp_error(mp);
+ }
+}
+
+@ When a dependent variable becomes known, the following routine
+removes its dependency list. Here |p| points to the variable, and
+|q| points to the dependency list (which is one node long).
+
+@<Declarations@>=
+static void mp_make_known (MP mp,pointer p, pointer q) ;
+
+@ @c void mp_make_known (MP mp,pointer p, pointer q) {
+ int t; /* the previous type */
+ prev_dep(mp_link(q))=prev_dep(p);
+ mp_link(prev_dep(p))=mp_link(q); t=mp_type(p);
+ mp_type(p)=mp_known; value(p)=value(q); mp_free_node(mp, q,dep_node_size);
+ if ( abs(value(p))>=fraction_one ) mp_val_too_big(mp, value(p));
+ if (( mp->internal[mp_tracing_equations]>0) && mp_interesting(mp, p) ) {
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "#### ");
+@:]]]\#\#\#\#_}{\.{\#\#\#\#}@>
+ mp_print_variable_name(mp, p);
+ mp_print_char(mp, xord('=')); mp_print_scaled(mp, value(p));
+ mp_end_diagnostic(mp, false);
+ }
+ if (( mp->cur_exp==p ) && mp->cur_type==t ) {
+ mp->cur_type=mp_known; mp->cur_exp=value(p);
+ mp_free_node(mp, p,value_node_size);
+ }
+}
+
+@ The |fix_dependencies| routine is called into action when |fix_needed|
+has been triggered. The program keeps a list~|s| of independent variables
+whose coefficients must be divided by~4.
+
+In unusual cases, this fixup process might reduce one or more coefficients
+to zero, so that a variable will become known more or less by default.
+
+@<Declarations@>=
+static void mp_fix_dependencies (MP mp);
+
+@ @c
+static void mp_fix_dependencies (MP mp) {
+ pointer p,q,r,s,t; /* list manipulation registers */
+ pointer x; /* an independent variable */
+ r=mp_link(dep_head); s=null;
+ while ( r!=dep_head ){
+ t=r;
+ @<Run through the dependency list for variable |t|, fixing
+ all nodes, and ending with final link~|q|@>;
+ r=mp_link(q);
+ if ( q==dep_list(t) ) mp_make_known(mp, t,q);
+ }
+ while ( s!=null ) {
+ p=mp_link(s); x=mp_info(s); free_avail(s); s=p;
+ mp_type(x)=mp_independent; value(x)=value(x)+2;
+ }
+ mp->fix_needed=false;
+}
+
+@ @d independent_being_fixed 1 /* this variable already appears in |s| */
+
+@<Run through the dependency list for variable |t|...@>=
+r=value_loc(t); /* |mp_link(r)=dep_list(t)| */
+while (1) {
+ q=mp_link(r); x=mp_info(q);
+ if ( x==null ) break;
+ if ( mp_type(x)<=independent_being_fixed ) {
+ if ( mp_type(x)<independent_being_fixed ) {
+ p=mp_get_avail(mp); mp_link(p)=s; s=p;
+ mp_info(s)=x; mp_type(x)=independent_being_fixed;
+ }
+ value(q)=value(q) / 4;
+ if ( value(q)==0 ) {
+ mp_link(r)=mp_link(q); mp_free_node(mp, q,dep_node_size); q=r;
+ }
+ }
+ r=q;
+}
+
+
+@ The |new_dep| routine installs a dependency list~|p| into the value node~|q|,
+linking it into the list of all known dependencies. We assume that
+|dep_final| points to the final node of list~|p|.
+
+@c
+static void mp_new_dep (MP mp,pointer q, pointer p) {
+ pointer r; /* what used to be the first dependency */
+ dep_list(q)=p; prev_dep(q)=dep_head;
+ r=mp_link(dep_head); mp_link(mp->dep_final)=r; prev_dep(r)=mp->dep_final;
+ mp_link(dep_head)=q;
+}
+
+@ Here is one of the ways a dependency list gets started.
+The |const_dependency| routine produces a list that has nothing but
+a constant term.
+
+@c static pointer mp_const_dependency (MP mp, scaled v) {
+ mp->dep_final=mp_get_node(mp, dep_node_size);
+ value(mp->dep_final)=v; mp_info(mp->dep_final)=null;
+ return mp->dep_final;
+}
+
+@ And here's a more interesting way to start a dependency list from scratch:
+The parameter to |single_dependency| is the location of an
+independent variable~|x|, and the result is the simple dependency list
+`|x+0|'.
+
+In the unlikely event that the given independent variable has been doubled so
+often that we can't refer to it with a nonzero coefficient,
+|single_dependency| returns the simple list `0'. This case can be
+recognized by testing that the returned list pointer is equal to
+|dep_final|.
+
+@c
+static pointer mp_single_dependency (MP mp,pointer p) {
+ pointer q; /* the new dependency list */
+ integer m; /* the number of doublings */
+ m=value(p) % s_scale;
+ if ( m>28 ) {
+ return mp_const_dependency(mp, 0);
+ } else {
+ q=mp_get_node(mp, dep_node_size);
+ value(q)=(integer)two_to_the(28-m); mp_info(q)=p;
+ mp_link(q)=mp_const_dependency(mp, 0);
+ return q;
+ }
+}
+
+@ We sometimes need to make an exact copy of a dependency list.
+
+@c
+static pointer mp_copy_dep_list (MP mp,pointer p) {
+ pointer q; /* the new dependency list */
+ q=mp_get_node(mp, dep_node_size); mp->dep_final=q;
+ while (1) {
+ mp_info(mp->dep_final)=mp_info(p); value(mp->dep_final)=value(p);
+ if ( mp_info(mp->dep_final)==null ) break;
+ mp_link(mp->dep_final)=mp_get_node(mp, dep_node_size);
+ mp->dep_final=mp_link(mp->dep_final); p=mp_link(p);
+ }
+ return q;
+}
+
+@ But how do variables normally become known? Ah, now we get to the heart of the
+equation-solving mechanism. The |linear_eq| procedure is given a |dependent|
+or |mp_proto_dependent| list,~|p|, in which at least one independent variable
+appears. It equates this list to zero, by choosing an independent variable
+with the largest coefficient and making it dependent on the others. The
+newly dependent variable is eliminated from all current dependencies,
+thereby possibly making other dependent variables known.
+
+The given list |p| is, of course, totally destroyed by all this processing.
+
+@c
+static void mp_linear_eq (MP mp, pointer p, quarterword t) {
+ pointer q,r,s; /* for link manipulation */
+ pointer x; /* the variable that loses its independence */
+ integer n; /* the number of times |x| had been halved */
+ integer v; /* the coefficient of |x| in list |p| */
+ pointer prev_r; /* lags one step behind |r| */
+ pointer final_node; /* the constant term of the new dependency list */
+ integer w; /* a tentative coefficient */
+ @<Find a node |q| in list |p| whose coefficient |v| is largest@>;
+ x=mp_info(q); n=value(x) % s_scale;
+ @<Divide list |p| by |-v|, removing node |q|@>;
+ if ( mp->internal[mp_tracing_equations]>0 ) {
+ @<Display the new dependency@>;
+ }
+ @<Simplify all existing dependencies by substituting for |x|@>;
+ @<Change variable |x| from |independent| to |dependent| or |known|@>;
+ if ( mp->fix_needed ) mp_fix_dependencies(mp);
+}
+
+@ @<Find a node |q| in list |p| whose coefficient |v| is largest@>=
+q=p; r=mp_link(p); v=value(q);
+while ( mp_info(r)!=null ) {
+ if ( abs(value(r))>abs(v) ) { q=r; v=value(r); };
+ r=mp_link(r);
+}
+
+@ Here we want to change the coefficients from |scaled| to |fraction|,
+except in the constant term. In the common case of a trivial equation
+like `\.{x=3.14}', we will have |v=-fraction_one|, |q=p|, and |t=mp_dependent|.
+
+@<Divide list |p| by |-v|, removing node |q|@>=
+s=temp_head; mp_link(s)=p; r=p;
+do {
+ if ( r==q ) {
+ mp_link(s)=mp_link(r); mp_free_node(mp, r,dep_node_size);
+ } else {
+ w=mp_make_fraction(mp, value(r),v);
+ if ( abs(w)<=half_fraction_threshold ) {
+ mp_link(s)=mp_link(r); mp_free_node(mp, r,dep_node_size);
+ } else {
+ value(r)=-w; s=r;
+ }
+ }
+ r=mp_link(s);
+} while (mp_info(r)!=null);
+if ( t==mp_proto_dependent ) {
+ value(r)=-mp_make_scaled(mp, value(r),v);
+} else if ( v!=-fraction_one ) {
+ value(r)=-mp_make_fraction(mp, value(r),v);
+}
+final_node=r; p=mp_link(temp_head)
+
+@ @<Display the new dependency@>=
+if ( mp_interesting(mp, x) ) {
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "## ");
+ mp_print_variable_name(mp, x);
+@:]]]\#\#_}{\.{\#\#}@>
+ w=n;
+ while ( w>0 ) { mp_print(mp, "*4"); w=w-2; };
+ mp_print_char(mp, xord('=')); mp_print_dependency(mp, p,mp_dependent);
+ mp_end_diagnostic(mp, false);
+}
+
+@ @<Simplify all existing dependencies by substituting for |x|@>=
+prev_r=dep_head; r=mp_link(dep_head);
+while ( r!=dep_head ) {
+ s=dep_list(r); q=mp_p_with_x_becoming_q(mp, s,x,p,mp_type(r));
+ if ( mp_info(q)==null ) {
+ mp_make_known(mp, r,q);
+ } else {
+ dep_list(r)=q;
+ do { q=mp_link(q); } while (mp_info(q)!=null);
+ prev_r=q;
+ }
+ r=mp_link(prev_r);
+}
+
+@ @<Change variable |x| from |independent| to |dependent| or |known|@>=
+if ( n>0 ) @<Divide list |p| by $2^n$@>;
+if ( mp_info(p)==null ) {
+ mp_type(x)=mp_known;
+ value(x)=value(p);
+ if ( abs(value(x))>=fraction_one ) mp_val_too_big(mp, value(x));
+ mp_free_node(mp, p,dep_node_size);
+ if ( mp->cur_exp==x ) if ( mp->cur_type==mp_independent ) {
+ mp->cur_exp=value(x); mp->cur_type=mp_known;
+ mp_free_node(mp, x,value_node_size);
+ }
+} else {
+ mp_type(x)=mp_dependent; mp->dep_final=final_node; mp_new_dep(mp, x,p);
+ if ( mp->cur_exp==x ) if ( mp->cur_type==mp_independent ) mp->cur_type=mp_dependent;
+}
+
+@ @<Divide list |p| by $2^n$@>=
+{
+ s=temp_head; mp_link(temp_head)=p; r=p;
+ do {
+ if ( n>30 ) w=0;
+ else w=value(r) / two_to_the(n);
+ if ( (abs(w)<=half_fraction_threshold)&&(mp_info(r)!=null) ) {
+ mp_link(s)=mp_link(r);
+ mp_free_node(mp, r,dep_node_size);
+ } else {
+ value(r)=w; s=r;
+ }
+ r=mp_link(s);
+ } while (mp_info(s)!=null);
+ p=mp_link(temp_head);
+}
+
+@ The |check_mem| procedure, which is used only when \MP\ is being
+debugged, makes sure that the current dependency lists are well formed.
+
+@<Check the list of linear dependencies@>=
+q=dep_head; p=mp_link(q);
+while ( p!=dep_head ) {
+ if ( prev_dep(p)!=q ) {
+ mp_print_nl(mp, "Bad PREVDEP at "); mp_print_int(mp, p);
+@.Bad PREVDEP...@>
+ }
+ p=dep_list(p);
+ while (1) {
+ r=mp_info(p); q=p; p=mp_link(q);
+ if ( r==null ) break;
+ if ( value(mp_info(p))>=value(r) ) {
+ mp_print_nl(mp, "Out of order at "); mp_print_int(mp, p);
+@.Out of order...@>
+ }
+ }
+}
+
+@* \[25] Dynamic nonlinear equations.
+Variables of numeric type are maintained by the general scheme of
+independent, dependent, and known values that we have just studied;
+and the components of pair and transform variables are handled in the
+same way. But \MP\ also has five other types of values: \&{boolean},
+\&{string}, \&{pen}, \&{path}, and \&{picture}; what about them?
+
+Equations are allowed between nonlinear quantities, but only in a
+simple form. Two variables that haven't yet been assigned values are
+either equal to each other, or they're not.
+
+Before a boolean variable has received a value, its type is |mp_unknown_boolean|;
+similarly, there are variables whose type is |mp_unknown_string|, |mp_unknown_pen|,
+|mp_unknown_path|, and |mp_unknown_picture|. In such cases the value is either
+|null| (which means that no other variables are equivalent to this one), or
+it points to another variable of the same undefined type. The pointers in the
+latter case form a cycle of nodes, which we shall call a ``ring.''
+Rings of undefined variables may include capsules, which arise as
+intermediate results within expressions or as \&{expr} parameters to macros.
+
+When one member of a ring receives a value, the same value is given to
+all the other members. In the case of paths and pictures, this implies
+making separate copies of a potentially large data structure; users should
+restrain their enthusiasm for such generality, unless they have lots and
+lots of memory space.
+
+@ The following procedure is called when a capsule node is being
+added to a ring (e.g., when an unknown variable is mentioned in an expression).
+
+@c
+static pointer mp_new_ring_entry (MP mp,pointer p) {
+ pointer q; /* the new capsule node */
+ q=mp_get_node(mp, value_node_size); mp_name_type(q)=mp_capsule;
+ mp_type(q)=mp_type(p);
+ if ( value(p)==null ) value(q)=p; else value(q)=value(p);
+ value(p)=q;
+ return q;
+}
+
+@ Conversely, we might delete a capsule or a variable before it becomes known.
+The following procedure simply detaches a quantity from its ring,
+without recycling the storage.
+
+@<Declarations@>=
+static void mp_ring_delete (MP mp,pointer p);
+
+@ @c
+void mp_ring_delete (MP mp,pointer p) {
+ pointer q;
+ q=value(p);
+ if ( q!=null ) if ( q!=p ){
+ while ( value(q)!=p ) q=value(q);
+ value(q)=value(p);
+ }
+}
+
+@ Eventually there might be an equation that assigns values to all of the
+variables in a ring. The |nonlinear_eq| subroutine does the necessary
+propagation of values.
+
+If the parameter |flush_p| is |true|, node |p| itself needn't receive a
+value, it will soon be recycled.
+
+@c
+static void mp_nonlinear_eq (MP mp,integer v, pointer p, boolean flush_p) {
+ quarterword t; /* the type of ring |p| */
+ pointer q,r; /* link manipulation registers */
+ t=mp_type(p)-unknown_tag; q=value(p);
+ if ( flush_p ) mp_type(p)=mp_vacuous; else p=q;
+ do {
+ r=value(q); mp_type(q)=t;
+ switch (t) {
+ case mp_boolean_type: value(q)=v; break;
+ case mp_string_type: value(q)=v; add_str_ref(v); break;
+ case mp_pen_type: value(q)=copy_pen(v); break;
+ case mp_path_type: value(q)=mp_copy_path(mp, v); break;
+ case mp_picture_type: value(q)=v; add_edge_ref(v); break;
+ } /* there ain't no more cases */
+ q=r;
+ } while (q!=p);
+}
+
+@ If two members of rings are equated, and if they have the same type,
+the |ring_merge| procedure is called on to make them equivalent.
+
+@c
+static void mp_ring_merge (MP mp,pointer p, pointer q) {
+ pointer r; /* traverses one list */
+ r=value(p);
+ while ( r!=p ) {
+ if ( r==q ) {
+ @<Exclaim about a redundant equation@>;
+ return;
+ };
+ r=value(r);
+ }
+ r=value(p); value(p)=value(q); value(q)=r;
+}
+
+@ @<Exclaim about a redundant equation@>=
+{
+ print_err("Redundant equation");
+@.Redundant equation@>
+ help2("I already knew that this equation was true.",
+ "But perhaps no harm has been done; let's continue.");
+ mp_put_get_error(mp);
+}
+
+@* \[26] Introduction to the syntactic routines.
+Let's pause a moment now and try to look at the Big Picture.
+The \MP\ program consists of three main parts: syntactic routines,
+semantic routines, and output routines. The chief purpose of the
+syntactic routines is to deliver the user's input to the semantic routines,
+while parsing expressions and locating operators and operands. The
+semantic routines act as an interpreter responding to these operators,
+which may be regarded as commands. And the output routines are
+periodically called on to produce compact font descriptions that can be
+used for typesetting or for making interim proof drawings. We have
+discussed the basic data structures and many of the details of semantic
+operations, so we are good and ready to plunge into the part of \MP\ that
+actually controls the activities.
+
+Our current goal is to come to grips with the |get_next| procedure,
+which is the keystone of \MP's input mechanism. Each call of |get_next|
+sets the value of three variables |cur_cmd|, |cur_mod|, and |cur_sym|,
+representing the next input token.
+$$\vbox{\halign{#\hfil\cr
+ \hbox{|cur_cmd| denotes a command code from the long list of codes
+ given earlier;}\cr
+ \hbox{|cur_mod| denotes a modifier of the command code;}\cr
+ \hbox{|cur_sym| is the hash address of the symbolic token that was
+ just scanned,}\cr
+ \hbox{\qquad or zero in the case of a numeric or string
+ or capsule token.}\cr}}$$
+Underlying this external behavior of |get_next| is all the machinery
+necessary to convert from character files to tokens. At a given time we
+may be only partially finished with the reading of several files (for
+which \&{input} was specified), and partially finished with the expansion
+of some user-defined macros and/or some macro parameters, and partially
+finished reading some text that the user has inserted online,
+and so on. When reading a character file, the characters must be
+converted to tokens; comments and blank spaces must
+be removed, numeric and string tokens must be evaluated.
+
+To handle these situations, which might all be present simultaneously,
+\MP\ uses various stacks that hold information about the incomplete
+activities, and there is a finite state control for each level of the
+input mechanism. These stacks record the current state of an implicitly
+recursive process, but the |get_next| procedure is not recursive.
+
+@<Glob...@>=
+integer cur_cmd; /* current command set by |get_next| */
+integer cur_mod; /* operand of current command */
+halfword cur_sym; /* hash address of current symbol */
+
+@ The |print_cmd_mod| routine prints a symbolic interpretation of a
+command code and its modifier.
+It consists of a rather tedious sequence of print
+commands, and most of it is essentially an inverse to the |primitive|
+routine that enters a \MP\ primitive into |hash| and |eqtb|. Therefore almost
+all of this procedure appears elsewhere in the program, together with the
+corresponding |primitive| calls.
+
+@<Declarations@>=
+static void mp_print_cmd_mod (MP mp,integer c, integer m) ;
+
+@ @c
+void mp_print_cmd_mod (MP mp,integer c, integer m) {
+ switch (c) {
+ @<Cases of |print_cmd_mod| for symbolic printing of primitives@>
+ default: mp_print(mp, "[unknown command code!]"); break;
+ }
+}
+
+@ Here is a procedure that displays a given command in braces, in the
+user's transcript file.
+
+@d show_cur_cmd_mod mp_show_cmd_mod(mp, mp->cur_cmd,mp->cur_mod)
+
+@c
+static void mp_show_cmd_mod (MP mp,integer c, integer m) {
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "{");
+ mp_print_cmd_mod(mp, c,m); mp_print_char(mp, xord('}'));
+ mp_end_diagnostic(mp, false);
+}
+
+@* \[27] Input stacks and states.
+The state of \MP's input mechanism appears in the input stack, whose
+entries are records with five fields, called |index|, |start|, |loc|,
+|limit|, and |name|. The top element of this stack is maintained in a
+global variable for which no subscripting needs to be done; the other
+elements of the stack appear in an array. Hence the stack is declared thus:
+
+@<Types...@>=
+typedef struct {
+ quarterword index_field;
+ halfword start_field, loc_field, limit_field, name_field;
+} in_state_record;
+
+@ @<Glob...@>=
+in_state_record *input_stack;
+integer input_ptr; /* first unused location of |input_stack| */
+integer max_in_stack; /* largest value of |input_ptr| when pushing */
+in_state_record cur_input; /* the ``top'' input state */
+int stack_size; /* maximum number of simultaneous input sources */
+
+@ @<Allocate or initialize ...@>=
+mp->stack_size = 300;
+mp->input_stack = xmalloc((mp->stack_size+1),sizeof(in_state_record));
+
+@ @<Dealloc variables@>=
+xfree(mp->input_stack);
+
+@ We've already defined the special variable |loc==cur_input.loc_field|
+in our discussion of basic input-output routines. The other components of
+|cur_input| are defined in the same way:
+
+@d iindex mp->cur_input.index_field /* reference for buffer information */
+@d start mp->cur_input.start_field /* starting position in |buffer| */
+@d limit mp->cur_input.limit_field /* end of current line in |buffer| */
+@d name mp->cur_input.name_field /* name of the current file */
+
+@ Let's look more closely now at the five control variables
+(|index|,~|start|,~|loc|,~|limit|,~|name|),
+assuming that \MP\ is reading a line of characters that have been input
+from some file or from the user's terminal. There is an array called
+|buffer| that acts as a stack of all lines of characters that are
+currently being read from files, including all lines on subsidiary
+levels of the input stack that are not yet completed. \MP\ will return to
+the other lines when it is finished with the present input file.
+
+(Incidentally, on a machine with byte-oriented addressing, it would be
+appropriate to combine |buffer| with the |str_pool| array,
+letting the buffer entries grow downward from the top of the string pool
+and checking that these two tables don't bump into each other.)
+
+The line we are currently working on begins in position |start| of the
+buffer; the next character we are about to read is |buffer[loc]|; and
+|limit| is the location of the last character present. We always have
+|loc<=limit|. For convenience, |buffer[limit]| has been set to |"%"|, so
+that the end of a line is easily sensed.
+
+The |name| variable is a string number that designates the name of
+the current file, if we are reading an ordinary text file. Special codes
+|is_term..max_spec_src| indicate other sources of input text.
+
+@d is_term 0 /* |name| value when reading from the terminal for normal input */
+@d is_read 1 /* |name| value when executing a \&{readstring} or \&{readfrom} */
+@d is_scantok 2 /* |name| value when reading text generated by \&{scantokens} */
+@d max_spec_src is_scantok
+
+@ Additional information about the current line is available via the
+|index| variable, which counts how many lines of characters are present
+in the buffer below the current level. We have |index=0| when reading
+from the terminal and prompting the user for each line; then if the user types,
+e.g., `\.{input figs}', we will have |index=1| while reading
+the file \.{figs.mp}. However, it does not follow that |index| is the
+same as the input stack pointer, since many of the levels on the input
+stack may come from token lists and some |index| values may correspond
+to \.{MPX} files that are not currently on the stack.
+
+The global variable |in_open| is equal to the highest |index| value counting
+\.{MPX} files but excluding token-list input levels. Thus, the number of
+partially read lines in the buffer is |in_open+1| and we have |in_open>=index|
+when we are not reading a token list.
+
+If we are not currently reading from the terminal,
+we are reading from the file variable |input_file[index]|. We use
+the notation |terminal_input| as a convenient abbreviation for |name=is_term|,
+and |cur_file| as an abbreviation for |input_file[index]|.
+
+When \MP\ is not reading from the terminal, the global variable |line| contains
+the line number in the current file, for use in error messages. More precisely,
+|line| is a macro for |line_stack[index]| and the |line_stack| array gives
+the line number for each file in the |input_file| array.
+
+When an \.{MPX} file is opened the file name is stored in the |mpx_name|
+array so that the name doesn't get lost when the file is temporarily removed
+from the input stack.
+Thus when |input_file[k]| is an \.{MPX} file, its name is |mpx_name[k]|
+and it contains translated \TeX\ pictures for |input_file[k-1]|.
+Since this is not an \.{MPX} file, we have
+$$ \hbox{|mpx_name[k-1]<=absent|}. $$
+This |name| field is set to |finished| when |input_file[k]| is completely
+read.
+
+If more information about the input state is needed, it can be
+included in small arrays like those shown here. For example,
+the current page or segment number in the input file might be put
+into a variable |page|, that is really a macro for the current entry
+in `\ignorespaces|page_stack:array[0..max_in_open] of integer|\unskip'
+by analogy with |line_stack|.
+@^system dependencies@>
+
+@d terminal_input (name==is_term) /* are we reading from the terminal? */
+@d cur_file mp->input_file[iindex] /* the current |void *| variable */
+@d line mp->line_stack[iindex] /* current line number in the current source file */
+@d in_name mp->iname_stack[iindex] /* a string used to construct \.{MPX} file names */
+@d in_area mp->iarea_stack[iindex] /* another string for naming \.{MPX} files */
+@d absent 1 /* |name_field| value for unused |mpx_in_stack| entries */
+@d mpx_reading (mp->mpx_name[iindex]>absent)
+ /* when reading a file, is it an \.{MPX} file? */
+@d mpx_finished 0
+ /* |name_field| value when the corresponding \.{MPX} file is finished */
+
+@<Glob...@>=
+integer in_open; /* the number of lines in the buffer, less one */
+integer in_open_max; /* highest value of |in_open| ever seen */
+unsigned int open_parens; /* the number of open text files */
+void * *input_file ;
+integer *line_stack ; /* the line number for each file */
+char * *iname_stack; /* used for naming \.{MPX} files */
+char * *iarea_stack; /* used for naming \.{MPX} files */
+halfword*mpx_name ;
+
+@ @<Allocate or ...@>=
+mp->input_file = xmalloc((mp->max_in_open+1),sizeof(void *));
+mp->line_stack = xmalloc((mp->max_in_open+1),sizeof(integer));
+mp->iname_stack = xmalloc((mp->max_in_open+1),sizeof(char *));
+mp->iarea_stack = xmalloc((mp->max_in_open+1),sizeof(char *));
+mp->mpx_name = xmalloc((mp->max_in_open+1),sizeof(halfword));
+{
+ int k;
+ for (k=0;k<=mp->max_in_open;k++) {
+ mp->iname_stack[k] =NULL;
+ mp->iarea_stack[k] =NULL;
+ }
+}
+
+@ @<Dealloc variables@>=
+{
+ int l;
+ for (l=0;l<=mp->max_in_open;l++) {
+ xfree(mp->iname_stack[l]);
+ xfree(mp->iarea_stack[l]);
+ }
+}
+xfree(mp->input_file);
+xfree(mp->line_stack);
+xfree(mp->iname_stack);
+xfree(mp->iarea_stack);
+xfree(mp->mpx_name);
+
+
+@ However, all this discussion about input state really applies only to the
+case that we are inputting from a file. There is another important case,
+namely when we are currently getting input from a token list. In this case
+|iindex>max_in_open|, and the conventions about the other state variables
+are different:
+
+\yskip\hang|loc| is a pointer to the current node in the token list, i.e.,
+the node that will be read next. If |loc=null|, the token list has been
+fully read.
+
+\yskip\hang|start| points to the first node of the token list; this node
+may or may not contain a reference count, depending on the type of token
+list involved.
+
+\yskip\hang|token_type|, which takes the place of |iindex| in the
+discussion above, is a code number that explains what kind of token list
+is being scanned.
+
+\yskip\hang|name| points to the |eqtb| address of the control sequence
+being expanded, if the current token list is a macro not defined by
+\&{vardef}. Macros defined by \&{vardef} have |name=null|; their name
+can be deduced by looking at their first two parameters.
+
+\yskip\hang|param_start|, which takes the place of |limit|, tells where
+the parameters of the current macro or loop text begin in the |param_stack|.
+
+\yskip\noindent The |token_type| can take several values, depending on
+where the current token list came from:
+
+\yskip
+\indent|forever_text|, if the token list being scanned is the body of
+a \&{forever} loop;
+
+\indent|loop_text|, if the token list being scanned is the body of
+a \&{for} or \&{forsuffixes} loop;
+
+\indent|parameter|, if a \&{text} or \&{suffix} parameter is being scanned;
+
+\indent|backed_up|, if the token list being scanned has been inserted as
+`to be read again'.
+
+\indent|inserted|, if the token list being scanned has been inserted as
+part of error recovery;
+
+\indent|macro|, if the expansion of a user-defined symbolic token is being
+scanned.
+
+\yskip\noindent
+The token list begins with a reference count if and only if |token_type=
+macro|.
+@^reference counts@>
+
+@d token_type iindex /* type of current token list */
+@d token_state (iindex>(int)mp->max_in_open) /* are we scanning a token list? */
+@d file_state (iindex<=(int)mp->max_in_open) /* are we scanning a file line? */
+@d param_start limit /* base of macro parameters in |param_stack| */
+@d forever_text (mp->max_in_open+1) /* |token_type| code for loop texts */
+@d loop_text (mp->max_in_open+2) /* |token_type| code for loop texts */
+@d parameter (mp->max_in_open+3) /* |token_type| code for parameter texts */
+@d backed_up (mp->max_in_open+4) /* |token_type| code for texts to be reread */
+@d inserted (mp->max_in_open+5) /* |token_type| code for inserted texts */
+@d macro (mp->max_in_open+6) /* |token_type| code for macro replacement texts */
+
+@ The |param_stack| is an auxiliary array used to hold pointers to the token
+lists for parameters at the current level and subsidiary levels of input.
+This stack grows at a different rate from the others.
+
+@<Glob...@>=
+pointer *param_stack; /* token list pointers for parameters */
+integer param_ptr; /* first unused entry in |param_stack| */
+integer max_param_stack; /* largest value of |param_ptr| */
+
+@ @<Allocate or initialize ...@>=
+mp->param_stack = xmalloc((mp->param_size+1),sizeof(pointer));
+
+@ @<Dealloc variables@>=
+xfree(mp->param_stack);
+
+@ Notice that the |line| isn't valid when |token_state| is true because it
+depends on |iindex|. If we really need to know the line number for the
+topmost file in the iindex stack we use the following function. If a page
+number or other information is needed, this routine should be modified to
+compute it as well.
+@^system dependencies@>
+
+@<Declarations@>=
+static integer mp_true_line (MP mp) ;
+
+@ @c
+integer mp_true_line (MP mp) {
+ int k; /* an index into the input stack */
+ if ( file_state && (name>max_spec_src) ) {
+ return line;
+ } else {
+ k=mp->input_ptr;
+ while ((k>0) &&
+ ((mp->input_stack[(k-1)].index_field>mp->max_in_open)||
+ (mp->input_stack[(k-1)].name_field<=max_spec_src))) {
+ decr(k);
+ }
+ return (k>0 ? mp->line_stack[(k-1)] : 0 );
+ }
+}
+
+@ Thus, the ``current input state'' can be very complicated indeed; there
+can be many levels and each level can arise in a variety of ways. The
+|show_context| procedure, which is used by \MP's error-reporting routine to
+print out the current input state on all levels down to the most recent
+line of characters from an input file, illustrates most of these conventions.
+The global variable |file_ptr| contains the lowest level that was
+displayed by this procedure.
+
+@<Glob...@>=
+integer file_ptr; /* shallowest level shown by |show_context| */
+
+@ The status at each level is indicated by printing two lines, where the first
+line indicates what was read so far and the second line shows what remains
+to be read. The context is cropped, if necessary, so that the first line
+contains at most |half_error_line| characters, and the second contains
+at most |error_line|. Non-current input levels whose |token_type| is
+`|backed_up|' are shown only if they have not been fully read.
+
+@c void mp_show_context (MP mp) { /* prints where the scanner is */
+ unsigned old_setting; /* saved |selector| setting */
+ @<Local variables for formatting calculations@>
+ mp->file_ptr=mp->input_ptr; mp->input_stack[mp->file_ptr]=mp->cur_input;
+ /* store current state */
+ while (1) {
+ mp->cur_input=mp->input_stack[mp->file_ptr]; /* enter into the context */
+ @<Display the current context@>;
+ if ( file_state )
+ if ( (name>max_spec_src) || (mp->file_ptr==0) ) break;
+ decr(mp->file_ptr);
+ }
+ mp->cur_input=mp->input_stack[mp->input_ptr]; /* restore original state */
+}
+
+@ @<Display the current context@>=
+if ( (mp->file_ptr==mp->input_ptr) || file_state ||
+ (token_type!=backed_up) || (loc!=null) ) {
+ /* we omit backed-up token lists that have already been read */
+ mp->tally=0; /* get ready to count characters */
+ old_setting=mp->selector;
+ if ( file_state ) {
+ @<Print location of current line@>;
+ @<Pseudoprint the line@>;
+ } else {
+ @<Print type of token list@>;
+ @<Pseudoprint the token list@>;
+ }
+ mp->selector=old_setting; /* stop pseudoprinting */
+ @<Print two lines using the tricky pseudoprinted information@>;
+}
+
+@ This routine should be changed, if necessary, to give the best possible
+indication of where the current line resides in the input file.
+For example, on some systems it is best to print both a page and line number.
+@^system dependencies@>
+
+@<Print location of current line@>=
+if ( name>max_spec_src ) {
+ mp_print_nl(mp, "l."); mp_print_int(mp, mp_true_line(mp));
+} else if ( terminal_input ) {
+ if ( mp->file_ptr==0 ) mp_print_nl(mp, "<*>");
+ else mp_print_nl(mp, "<insert>");
+} else if ( name==is_scantok ) {
+ mp_print_nl(mp, "<scantokens>");
+} else {
+ mp_print_nl(mp, "<read>");
+}
+mp_print_char(mp, xord(' '))
+
+@ Can't use case statement here because the |token_type| is not
+a constant expression.
+
+@<Print type of token list@>=
+{
+ if(token_type==forever_text) {
+ mp_print_nl(mp, "<forever> ");
+ } else if (token_type==loop_text) {
+ @<Print the current loop value@>;
+ } else if (token_type==parameter) {
+ mp_print_nl(mp, "<argument> ");
+ } else if (token_type==backed_up) {
+ if ( loc==null ) mp_print_nl(mp, "<recently read> ");
+ else mp_print_nl(mp, "<to be read again> ");
+ } else if (token_type==inserted) {
+ mp_print_nl(mp, "<inserted text> ");
+ } else if (token_type==macro) {
+ mp_print_ln(mp);
+ if ( name!=null ) mp_print_text(name);
+ else @<Print the name of a \&{vardef}'d macro@>;
+ mp_print(mp, "->");
+ } else {
+ mp_print_nl(mp, "?");/* this should never happen */
+@.?\relax@>
+ }
+}
+
+@ The parameter that corresponds to a loop text is either a token list
+(in the case of \&{forsuffixes}) or a ``capsule'' (in the case of \&{for}).
+We'll discuss capsules later; for now, all we need to know is that
+the |link| field in a capsule parameter is |void| and that
+|print_exp(p,0)| displays the value of capsule~|p| in abbreviated form.
+
+@<Print the current loop value@>=
+{ mp_print_nl(mp, "<for("); p=mp->param_stack[param_start];
+ if ( p!=null ) {
+ if ( mp_link(p)==mp_void ) mp_print_exp(mp, p,0); /* we're in a \&{for} loop */
+ else mp_show_token_list(mp, p,null,20,mp->tally);
+ }
+ mp_print(mp, ")> ");
+}
+
+@ The first two parameters of a macro defined by \&{vardef} will be token
+lists representing the macro's prefix and ``at point.'' By putting these
+together, we get the macro's full name.
+
+@<Print the name of a \&{vardef}'d macro@>=
+{ p=mp->param_stack[param_start];
+ if ( p==null ) {
+ mp_show_token_list(mp, mp->param_stack[param_start+1],null,20,mp->tally);
+ } else {
+ q=p;
+ while ( mp_link(q)!=null ) q=mp_link(q);
+ mp_link(q)=mp->param_stack[param_start+1];
+ mp_show_token_list(mp, p,null,20,mp->tally);
+ mp_link(q)=null;
+ }
+}
+
+@ Now it is necessary to explain a little trick. We don't want to store a long
+string that corresponds to a token list, because that string might take up
+lots of memory; and we are printing during a time when an error message is
+being given, so we dare not do anything that might overflow one of \MP's
+tables. So `pseudoprinting' is the answer: We enter a mode of printing
+that stores characters into a buffer of length |error_line|, where character
+$k+1$ is placed into \hbox{|trick_buf[k mod error_line]|} if
+|k<trick_count|, otherwise character |k| is dropped. Initially we set
+|tally:=0| and |trick_count:=1000000|; then when we reach the
+point where transition from line 1 to line 2 should occur, we
+set |first_count:=tally| and |trick_count:=@tmax@>(error_line,
+tally+1+error_line-half_error_line)|. At the end of the
+pseudoprinting, the values of |first_count|, |tally|, and
+|trick_count| give us all the information we need to print the two lines,
+and all of the necessary text is in |trick_buf|.
+
+Namely, let |l| be the length of the descriptive information that appears
+on the first line. The length of the context information gathered for that
+line is |k=first_count|, and the length of the context information
+gathered for line~2 is $m=\min(|tally|, |trick_count|)-k$. If |l+k<=h|,
+where |h=half_error_line|, we print |trick_buf[0..k-1]| after the
+descriptive information on line~1, and set |n:=l+k|; here |n| is the
+length of line~1. If $l+k>h$, some cropping is necessary, so we set |n:=h|
+and print `\.{...}' followed by
+$$\hbox{|trick_buf[(l+k-h+3)..k-1]|,}$$
+where subscripts of |trick_buf| are circular modulo |error_line|. The
+second line consists of |n|~spaces followed by |trick_buf[k..(k+m-1)]|,
+unless |n+m>error_line|; in the latter case, further cropping is done.
+This is easier to program than to explain.
+
+@<Local variables for formatting...@>=
+int i; /* index into |buffer| */
+integer l; /* length of descriptive information on line 1 */
+integer m; /* context information gathered for line 2 */
+int n; /* length of line 1 */
+integer p; /* starting or ending place in |trick_buf| */
+integer q; /* temporary index */
+
+@ The following code tells the print routines to gather
+the desired information.
+
+@d begin_pseudoprint {
+ l=mp->tally; mp->tally=0; mp->selector=pseudo;
+ mp->trick_count=1000000;
+}
+@d set_trick_count {
+ mp->first_count=mp->tally;
+ mp->trick_count=mp->tally+1+mp->error_line-mp->half_error_line;
+ if ( mp->trick_count<mp->error_line ) mp->trick_count=mp->error_line;
+}
+
+@ And the following code uses the information after it has been gathered.
+
+@<Print two lines using the tricky pseudoprinted information@>=
+if ( mp->trick_count==1000000 ) set_trick_count;
+ /* |set_trick_count| must be performed */
+if ( mp->tally<mp->trick_count ) m=mp->tally-mp->first_count;
+else m=mp->trick_count-mp->first_count; /* context on line 2 */
+if ( l+mp->first_count<=mp->half_error_line ) {
+ p=0; n=l+mp->first_count;
+} else {
+ mp_print(mp, "..."); p=l+mp->first_count-mp->half_error_line+3;
+ n=mp->half_error_line;
+}
+for (q=p;q<=mp->first_count-1;q++) {
+ mp_print_char(mp, mp->trick_buf[q % mp->error_line]);
+}
+mp_print_ln(mp);
+for (q=1;q<=n;q++) {
+ mp_print_char(mp, xord(' ')); /* print |n| spaces to begin line~2 */
+}
+if ( m+n<=mp->error_line ) p=mp->first_count+m;
+else p=mp->first_count+(mp->error_line-n-3);
+for (q=mp->first_count;q<=p-1;q++) {
+ mp_print_char(mp, mp->trick_buf[q % mp->error_line]);
+}
+if ( m+n>mp->error_line ) mp_print(mp, "...")
+
+@ But the trick is distracting us from our current goal, which is to
+understand the input state. So let's concentrate on the data structures that
+are being pseudoprinted as we finish up the |show_context| procedure.
+
+@<Pseudoprint the line@>=
+begin_pseudoprint;
+if ( limit>0 ) {
+ for (i=start;i<=limit-1;i++) {
+ if ( i==loc ) set_trick_count;
+ mp_print_str(mp, mp->buffer[i]);
+ }
+}
+
+@ @<Pseudoprint the token list@>=
+begin_pseudoprint;
+if ( token_type!=macro ) mp_show_token_list(mp, start,loc,100000,0);
+else mp_show_macro(mp, start,loc,100000)
+
+@ Here is the missing piece of |show_token_list| that is activated when the
+token beginning line~2 is about to be shown:
+
+@<Do magic computation@>=set_trick_count
+
+@* \[28] Maintaining the input stacks.
+The following subroutines change the input status in commonly needed ways.
+
+First comes |push_input|, which stores the current state and creates a
+new level (having, initially, the same properties as the old).
+
+@d push_input { /* enter a new input level, save the old */
+ if ( mp->input_ptr>mp->max_in_stack ) {
+ mp->max_in_stack=mp->input_ptr;
+ if ( mp->input_ptr==mp->stack_size ) {
+ int l = (mp->stack_size+(mp->stack_size/4));
+ XREALLOC(mp->input_stack, l, in_state_record);
+ mp->stack_size = l;
+ }
+ }
+ mp->input_stack[mp->input_ptr]=mp->cur_input; /* stack the record */
+ incr(mp->input_ptr);
+}
+
+@ And of course what goes up must come down.
+
+@d pop_input { /* leave an input level, re-enter the old */
+ decr(mp->input_ptr); mp->cur_input=mp->input_stack[mp->input_ptr];
+ }
+
+@ Here is a procedure that starts a new level of token-list input, given
+a token list |p| and its type |t|. If |t=macro|, the calling routine should
+set |name|, reset~|loc|, and increase the macro's reference count.
+
+@d back_list(A) mp_begin_token_list(mp, (A),backed_up) /* backs up a simple token list */
+
+@c
+static void mp_begin_token_list (MP mp,pointer p, quarterword t) {
+ push_input; start=p; token_type=t;
+ param_start=mp->param_ptr; loc=p;
+}
+
+@ When a token list has been fully scanned, the following computations
+should be done as we leave that level of input.
+@^inner loop@>
+
+@c
+static void mp_end_token_list (MP mp) { /* leave a token-list input level */
+ pointer p; /* temporary register */
+ if ( token_type>=backed_up ) { /* token list to be deleted */
+ if ( token_type<=inserted ) {
+ mp_flush_token_list(mp, start); goto DONE;
+ } else {
+ mp_delete_mac_ref(mp, start); /* update reference count */
+ }
+ }
+ while ( mp->param_ptr>param_start ) { /* parameters must be flushed */
+ decr(mp->param_ptr);
+ p=mp->param_stack[mp->param_ptr];
+ if ( p!=null ) {
+ if ( mp_link(p)==mp_void ) { /* it's an \&{expr} parameter */
+ mp_recycle_value(mp, p); mp_free_node(mp, p,value_node_size);
+ } else {
+ mp_flush_token_list(mp, p); /* it's a \&{suffix} or \&{text} parameter */
+ }
+ }
+ }
+DONE:
+ pop_input; check_interrupt;
+}
+
+@ The contents of |cur_cmd,cur_mod,cur_sym| are placed into an equivalent
+token by the |cur_tok| routine.
+@^inner loop@>
+
+@c @<Declare the procedure called |make_exp_copy|@>
+static pointer mp_cur_tok (MP mp) {
+ pointer p; /* a new token node */
+ quarterword save_type; /* |cur_type| to be restored */
+ integer save_exp; /* |cur_exp| to be restored */
+ if ( mp->cur_sym==0 ) {
+ if ( mp->cur_cmd==capsule_token ) {
+ save_type=mp->cur_type; save_exp=mp->cur_exp;
+ mp_make_exp_copy(mp, mp->cur_mod); p=mp_stash_cur_exp(mp); mp_link(p)=null;
+ mp->cur_type=save_type; mp->cur_exp=save_exp;
+ } else {
+ p=mp_get_node(mp, token_node_size);
+ value(p)=mp->cur_mod; mp_name_type(p)=mp_token;
+ if ( mp->cur_cmd==numeric_token ) mp_type(p)=mp_known;
+ else mp_type(p)=mp_string_type;
+ }
+ } else {
+ fast_get_avail(p); mp_info(p)=mp->cur_sym;
+ }
+ return p;
+}
+
+@ Sometimes \MP\ has read too far and wants to ``unscan'' what it has
+seen. The |back_input| procedure takes care of this by putting the token
+just scanned back into the input stream, ready to be read again.
+If |cur_sym<>0|, the values of |cur_cmd| and |cur_mod| are irrelevant.
+
+@<Declarations@>=
+static void mp_back_input (MP mp);
+
+@ @c void mp_back_input (MP mp) {/* undoes one token of input */
+ pointer p; /* a token list of length one */
+ p=mp_cur_tok(mp);
+ while ( token_state &&(loc==null) )
+ mp_end_token_list(mp); /* conserve stack space */
+ back_list(p);
+}
+
+@ The |back_error| routine is used when we want to restore or replace an
+offending token just before issuing an error message. We disable interrupts
+during the call of |back_input| so that the help message won't be lost.
+
+@ @c static void mp_back_error (MP mp) { /* back up one token and call |error| */
+ mp->OK_to_interrupt=false;
+ mp_back_input(mp);
+ mp->OK_to_interrupt=true; mp_error(mp);
+}
+static void mp_ins_error (MP mp) { /* back up one inserted token and call |error| */
+ mp->OK_to_interrupt=false;
+ mp_back_input(mp); token_type=inserted;
+ mp->OK_to_interrupt=true; mp_error(mp);
+}
+
+@ The |begin_file_reading| procedure starts a new level of input for lines
+of characters to be read from a file, or as an insertion from the
+terminal. It does not take care of opening the file, nor does it set |loc|
+or |limit| or |line|.
+@^system dependencies@>
+
+@c void mp_begin_file_reading (MP mp) {
+ if ( mp->in_open==mp->max_in_open )
+ mp_overflow(mp, "text input levels",mp->max_in_open);
+@:MetaPost capacity exceeded text input levels}{\quad text input levels@>
+ if ( mp->first==mp->buf_size )
+ mp_reallocate_buffer(mp,(mp->buf_size+(mp->buf_size/4)));
+ incr(mp->in_open); push_input; iindex=mp->in_open;
+ if (mp->in_open_max<mp->in_open)
+ mp->in_open_max=mp->in_open;
+ mp->mpx_name[iindex]=absent;
+ start=(halfword)mp->first;
+ name=is_term; /* |terminal_input| is now |true| */
+}
+
+@ Conversely, the variables must be downdated when such a level of input
+is finished. Any associated \.{MPX} file must also be closed and popped
+off the file stack.
+
+@c static void mp_end_file_reading (MP mp) {
+ if ( mp->in_open>iindex ) {
+ if ( (mp->mpx_name[mp->in_open]==absent)||(name<=max_spec_src) ) {
+ mp_confusion(mp, "endinput");
+@:this can't happen endinput}{\quad endinput@>
+ } else {
+ (mp->close_file)(mp,mp->input_file[mp->in_open]); /* close an \.{MPX} file */
+ delete_str_ref(mp->mpx_name[mp->in_open]);
+ decr(mp->in_open);
+ }
+ }
+ mp->first=(size_t)start;
+ if ( iindex!=mp->in_open ) mp_confusion(mp, "endinput");
+ if ( name>max_spec_src ) {
+ (mp->close_file)(mp,cur_file);
+ delete_str_ref(name);
+ xfree(in_name);
+ xfree(in_area);
+ }
+ pop_input; decr(mp->in_open);
+}
+
+@ Here is a function that tries to resume input from an \.{MPX} file already
+associated with the current input file. It returns |false| if this doesn't
+work.
+
+@c static boolean mp_begin_mpx_reading (MP mp) {
+ if ( mp->in_open!=iindex+1 ) {
+ return false;
+ } else {
+ if ( mp->mpx_name[mp->in_open]<=absent ) mp_confusion(mp, "mpx");
+@:this can't happen mpx}{\quad mpx@>
+ if ( mp->first==mp->buf_size )
+ mp_reallocate_buffer(mp,(mp->buf_size+(mp->buf_size/4)));
+ push_input; iindex=mp->in_open;
+ start=(halfword)mp->first;
+ name=mp->mpx_name[mp->in_open]; add_str_ref(name);
+ @<Put an empty line in the input buffer@>;
+ return true;
+ }
+}
+
+@ This procedure temporarily stops reading an \.{MPX} file.
+
+@c static void mp_end_mpx_reading (MP mp) {
+ if ( mp->in_open!=iindex ) mp_confusion(mp, "mpx");
+@:this can't happen mpx}{\quad mpx@>
+ if ( loc<limit ) {
+ @<Complain that we are not at the end of a line in the \.{MPX} file@>;
+ }
+ mp->first=(size_t)start;
+ pop_input;
+}
+
+@ Here we enforce a restriction that simplifies the input stacks considerably.
+This should not inconvenience the user because \.{MPX} files are generated
+by an auxiliary program called \.{DVItoMP}.
+
+@ @<Complain that we are not at the end of a line in the \.{MPX} file@>=
+{
+print_err("`mpxbreak' must be at the end of a line");
+help4("This file contains picture expressions for btex...etex",
+ "blocks. Such files are normally generated automatically",
+ "but this one seems to be messed up. I'm going to ignore",
+ "the rest of this line.");
+mp_error(mp);
+}
+
+@ In order to keep the stack from overflowing during a long sequence of
+inserted `\.{show}' commands, the following routine removes completed
+error-inserted lines from memory.
+
+@c void mp_clear_for_error_prompt (MP mp) {
+ while ( file_state && terminal_input &&
+ (mp->input_ptr>0)&&(loc==limit) ) mp_end_file_reading(mp);
+ mp_print_ln(mp); clear_terminal;
+}
+
+@ To get \MP's whole input mechanism going, we perform the following
+actions.
+
+@<Initialize the input routines@>=
+{ mp->input_ptr=0; mp->max_in_stack=0;
+ mp->in_open=0; mp->open_parens=0; mp->max_buf_stack=0;
+ mp->param_ptr=0; mp->max_param_stack=0;
+ mp->first=1;
+ start=1; iindex=0; line=0; name=is_term;
+ mp->mpx_name[0]=absent;
+ mp->force_eof=false;
+ if ( ! mp_init_terminal(mp) ) mp_jump_out(mp);
+ limit=(halfword)mp->last; mp->first=mp->last+1;
+ /* |init_terminal| has set |loc| and |last| */
+}
+
+@* \[29] Getting the next token.
+The heart of \MP's input mechanism is the |get_next| procedure, which
+we shall develop in the next few sections of the program. Perhaps we
+shouldn't actually call it the ``heart,'' however; it really acts as \MP's
+eyes and mouth, reading the source files and gobbling them up. And it also
+helps \MP\ to regurgitate stored token lists that are to be processed again.
+
+The main duty of |get_next| is to input one token and to set |cur_cmd|
+and |cur_mod| to that token's command code and modifier. Furthermore, if
+the input token is a symbolic token, that token's |hash| address
+is stored in |cur_sym|; otherwise |cur_sym| is set to zero.
+
+Underlying this simple description is a certain amount of complexity
+because of all the cases that need to be handled.
+However, the inner loop of |get_next| is reasonably short and fast.
+
+@ Before getting into |get_next|, we need to consider a mechanism by which
+\MP\ helps keep errors from propagating too far. Whenever the program goes
+into a mode where it keeps calling |get_next| repeatedly until a certain
+condition is met, it sets |scanner_status| to some value other than |normal|.
+Then if an input file ends, or if an `\&{outer}' symbol appears,
+an appropriate error recovery will be possible.
+
+The global variable |warning_info| helps in this error recovery by providing
+additional information. For example, |warning_info| might indicate the
+name of a macro whose replacement text is being scanned.
+
+@d normal 0 /* |scanner_status| at ``quiet times'' */
+@d skipping 1 /* |scanner_status| when false conditional text is being skipped */
+@d flushing 2 /* |scanner_status| when junk after a statement is being ignored */
+@d absorbing 3 /* |scanner_status| when a \&{text} parameter is being scanned */
+@d var_defining 4 /* |scanner_status| when a \&{vardef} is being scanned */
+@d op_defining 5 /* |scanner_status| when a macro \&{def} is being scanned */
+@d loop_defining 6 /* |scanner_status| when a \&{for} loop is being scanned */
+@d tex_flushing 7 /* |scanner_status| when skipping \TeX\ material */
+
+@<Glob...@>=
+integer scanner_status; /* are we scanning at high speed? */
+integer warning_info; /* if so, what else do we need to know,
+ in case an error occurs? */
+
+@ @<Initialize the input routines@>=
+mp->scanner_status=normal;
+
+@ The following subroutine
+is called when an `\&{outer}' symbolic token has been scanned or
+when the end of a file has been reached. These two cases are distinguished
+by |cur_sym|, which is zero at the end of a file.
+
+@c
+static boolean mp_check_outer_validity (MP mp) {
+ pointer p; /* points to inserted token list */
+ if ( mp->scanner_status==normal ) {
+ return true;
+ } else if ( mp->scanner_status==tex_flushing ) {
+ @<Check if the file has ended while flushing \TeX\ material and set the
+ result value for |check_outer_validity|@>;
+ } else {
+ mp->deletions_allowed=false;
+ @<Back up an outer symbolic token so that it can be reread@>;
+ if ( mp->scanner_status>skipping ) {
+ @<Tell the user what has run away and try to recover@>;
+ } else {
+ print_err("Incomplete if; all text was ignored after line ");
+@.Incomplete if...@>
+ mp_print_int(mp, mp->warning_info);
+ help3("A forbidden `outer' token occurred in skipped text.",
+ "This kind of error happens when you say `if...' and forget",
+ "the matching `fi'. I've inserted a `fi'; this might work.");
+ if ( mp->cur_sym==0 )
+ mp->help_line[2]="The file ended while I was skipping conditional text.";
+ mp->cur_sym=frozen_fi; mp_ins_error(mp);
+ }
+ mp->deletions_allowed=true;
+ return false;
+ }
+}
+
+@ @<Check if the file has ended while flushing \TeX\ material and set...@>=
+if ( mp->cur_sym!=0 ) {
+ return true;
+} else {
+ mp->deletions_allowed=false;
+ print_err("TeX mode didn't end; all text was ignored after line ");
+ mp_print_int(mp, mp->warning_info);
+ help2("The file ended while I was looking for the `etex' to",
+ "finish this TeX material. I've inserted `etex' now.");
+ mp->cur_sym = frozen_etex;
+ mp_ins_error(mp);
+ mp->deletions_allowed=true;
+ return false;
+}
+
+@ @<Back up an outer symbolic token so that it can be reread@>=
+if ( mp->cur_sym!=0 ) {
+ p=mp_get_avail(mp); mp_info(p)=mp->cur_sym;
+ back_list(p); /* prepare to read the symbolic token again */
+}
+
+@ @<Tell the user what has run away...@>=
+{
+ mp_runaway(mp); /* print the definition-so-far */
+ if ( mp->cur_sym==0 ) {
+ print_err("File ended");
+@.File ended while scanning...@>
+ } else {
+ print_err("Forbidden token found");
+@.Forbidden token found...@>
+ }
+ mp_print(mp, " while scanning ");
+ help4("I suspect you have forgotten an `enddef',",
+ "causing me to read past where you wanted me to stop.",
+ "I'll try to recover; but if the error is serious,",
+ "you'd better type `E' or `X' now and fix your file.");
+ switch (mp->scanner_status) {
+ @<Complete the error message,
+ and set |cur_sym| to a token that might help recover from the error@>
+ } /* there are no other cases */
+ mp_ins_error(mp);
+}
+
+@ As we consider various kinds of errors, it is also appropriate to
+change the first line of the help message just given; |help_line[3]|
+points to the string that might be changed.
+
+@<Complete the error message,...@>=
+case flushing:
+ mp_print(mp, "to the end of the statement");
+ mp->help_line[3]="A previous error seems to have propagated,";
+ mp->cur_sym=frozen_semicolon;
+ break;
+case absorbing:
+ mp_print(mp, "a text argument");
+ mp->help_line[3]="It seems that a right delimiter was left out,";
+ if ( mp->warning_info==0 ) {
+ mp->cur_sym=frozen_end_group;
+ } else {
+ mp->cur_sym=frozen_right_delimiter;
+ equiv(frozen_right_delimiter)=mp->warning_info;
+ }
+ break;
+case var_defining:
+case op_defining:
+ mp_print(mp, "the definition of ");
+ if ( mp->scanner_status==op_defining )
+ mp_print_text(mp->warning_info);
+ else
+ mp_print_variable_name(mp, mp->warning_info);
+ mp->cur_sym=frozen_end_def;
+ break;
+case loop_defining:
+ mp_print(mp, "the text of a ");
+ mp_print_text(mp->warning_info);
+ mp_print(mp, " loop");
+ mp->help_line[3]="I suspect you have forgotten an `endfor',";
+ mp->cur_sym=frozen_end_for;
+ break;
+
+@ The |runaway| procedure displays the first part of the text that occurred
+when \MP\ began its special |scanner_status|, if that text has been saved.
+
+@<Declarations@>=
+static void mp_runaway (MP mp) ;
+
+@ @c
+void mp_runaway (MP mp) {
+ if ( mp->scanner_status>flushing ) {
+ mp_print_nl(mp, "Runaway ");
+ switch (mp->scanner_status) {
+ case absorbing: mp_print(mp, "text?"); break;
+ case var_defining:
+ case op_defining: mp_print(mp,"definition?"); break;
+ case loop_defining: mp_print(mp, "loop?"); break;
+ } /* there are no other cases */
+ mp_print_ln(mp);
+ mp_show_token_list(mp, mp_link(hold_head),null,mp->error_line-10,0);
+ }
+}
+
+@ We need to mention a procedure that may be called by |get_next|.
+
+@<Declarations@>=
+static void mp_firm_up_the_line (MP mp);
+
+@ And now we're ready to take the plunge into |get_next| itself.
+Note that the behavior depends on the |scanner_status| because percent signs
+and double quotes need to be passed over when skipping TeX material.
+
+@c
+void mp_get_next (MP mp) {
+ /* sets |cur_cmd|, |cur_mod|, |cur_sym| to next token */
+@^inner loop@>
+ /*restart*/ /* go here to get the next input token */
+ /*exit*/ /* go here when the next input token has been got */
+ /*|common_ending|*/ /* go here to finish getting a symbolic token */
+ /*found*/ /* go here when the end of a symbolic token has been found */
+ /*switch*/ /* go here to branch on the class of an input character */
+ /*|start_numeric_token|,|start_decimal_token|,|fin_numeric_token|,|done|*/
+ /* go here at crucial stages when scanning a number */
+ int k; /* an index into |buffer| */
+ ASCII_code c; /* the current character in the buffer */
+ int class; /* its class number */
+ integer n,f; /* registers for decimal-to-binary conversion */
+RESTART:
+ mp->cur_sym=0;
+ if ( file_state ) {
+ @<Input from external file; |goto restart| if no input found,
+ or |return| if a non-symbolic token is found@>;
+ } else {
+ @<Input from token list; |goto restart| if end of list or
+ if a parameter needs to be expanded,
+ or |return| if a non-symbolic token is found@>;
+ }
+COMMON_ENDING:
+ @<Finish getting the symbolic token in |cur_sym|;
+ |goto restart| if it is illegal@>;
+}
+
+@ When a symbolic token is declared to be `\&{outer}', its command code
+is increased by |outer_tag|.
+@^inner loop@>
+
+@<Finish getting the symbolic token in |cur_sym|...@>=
+mp->cur_cmd=eq_type(mp->cur_sym); mp->cur_mod=equiv(mp->cur_sym);
+if ( mp->cur_cmd>=outer_tag ) {
+ if ( mp_check_outer_validity(mp) )
+ mp->cur_cmd=mp->cur_cmd-outer_tag;
+ else
+ goto RESTART;
+}
+
+@ A percent sign appears in |buffer[limit]|; this makes it unnecessary
+to have a special test for end-of-line.
+@^inner loop@>
+
+@<Input from external file;...@>=
+{
+SWITCH:
+ c=mp->buffer[loc]; incr(loc); class=mp->char_class[c];
+ switch (class) {
+ case digit_class: goto START_NUMERIC_TOKEN; break;
+ case period_class:
+ class=mp->char_class[mp->buffer[loc]];
+ if ( class>period_class ) {
+ goto SWITCH;
+ } else if ( class<period_class ) { /* |class=digit_class| */
+ n=0; goto START_DECIMAL_TOKEN;
+ }
+@:. }{\..\ token@>
+ break;
+ case space_class: goto SWITCH; break;
+ case percent_class:
+ if ( mp->scanner_status==tex_flushing ) {
+ if ( loc<limit ) goto SWITCH;
+ }
+ @<Move to next line of file, or |goto restart| if there is no next line@>;
+ check_interrupt;
+ goto SWITCH;
+ break;
+ case string_class:
+ if ( mp->scanner_status==tex_flushing ) goto SWITCH;
+ else @<Get a string token and |return|@>;
+ break;
+ case isolated_classes:
+ k=loc-1; goto FOUND; break;
+ case invalid_class:
+ if ( mp->scanner_status==tex_flushing ) goto SWITCH;
+ else @<Decry the invalid character and |goto restart|@>;
+ break;
+ default: break; /* letters, etc. */
+ }
+ k=loc-1;
+ while ( mp->char_class[mp->buffer[loc]]==class ) incr(loc);
+ goto FOUND;
+START_NUMERIC_TOKEN:
+ @<Get the integer part |n| of a numeric token;
+ set |f:=0| and |goto fin_numeric_token| if there is no decimal point@>;
+START_DECIMAL_TOKEN:
+ @<Get the fraction part |f| of a numeric token@>;
+FIN_NUMERIC_TOKEN:
+ @<Pack the numeric and fraction parts of a numeric token
+ and |return|@>;
+FOUND:
+ mp->cur_sym=mp_id_lookup(mp, k,loc-k);
+}
+
+@ We go to |restart| instead of to |SWITCH|, because we might enter
+|token_state| after the error has been dealt with
+(cf.\ |clear_for_error_prompt|).
+
+@<Decry the invalid...@>=
+{
+ print_err("Text line contains an invalid character");
+@.Text line contains...@>
+ help2("A funny symbol that I can\'t read has just been input.",
+ "Continue, and I'll forget that it ever happened.");
+ mp->deletions_allowed=false; mp_error(mp); mp->deletions_allowed=true;
+ goto RESTART;
+}
+
+@ @<Get a string token and |return|@>=
+{
+ if ( mp->buffer[loc]=='"' ) {
+ mp->cur_mod=null_str;
+ } else {
+ k=loc; mp->buffer[limit+1]=xord('"');
+ do {
+ incr(loc);
+ } while (mp->buffer[loc]!='"');
+ if ( loc>limit ) {
+ @<Decry the missing string delimiter and |goto restart|@>;
+ }
+ if ( loc==k+1 ) {
+ mp->cur_mod=mp->buffer[k];
+ } else {
+ str_room(loc-k);
+ do {
+ append_char(mp->buffer[k]); incr(k);
+ } while (k!=loc);
+ mp->cur_mod=mp_make_string(mp);
+ }
+ }
+ incr(loc); mp->cur_cmd=string_token;
+ return;
+}
+
+@ We go to |restart| after this error message, not to |SWITCH|,
+because the |clear_for_error_prompt| routine might have reinstated
+|token_state| after |error| has finished.
+
+@<Decry the missing string delimiter and |goto restart|@>=
+{
+ loc=limit; /* the next character to be read on this line will be |"%"| */
+ print_err("Incomplete string token has been flushed");
+@.Incomplete string token...@>
+ help3("Strings should finish on the same line as they began.",
+ "I've deleted the partial string; you might want to",
+ "insert another by typing, e.g., `I\"new string\"'.");
+ mp->deletions_allowed=false; mp_error(mp);
+ mp->deletions_allowed=true;
+ goto RESTART;
+}
+
+@ @<Get the integer part |n| of a numeric token...@>=
+n=c-'0';
+while ( mp->char_class[mp->buffer[loc]]==digit_class ) {
+ if ( n<32768 ) n=10*n+mp->buffer[loc]-'0';
+ incr(loc);
+}
+if ( mp->buffer[loc]=='.' )
+ if ( mp->char_class[mp->buffer[loc+1]]==digit_class )
+ goto DONE;
+f=0;
+goto FIN_NUMERIC_TOKEN;
+DONE: incr(loc)
+
+@ @<Get the fraction part |f| of a numeric token@>=
+k=0;
+do {
+ if ( k<17 ) { /* digits for |k>=17| cannot affect the result */
+ mp->dig[k]=mp->buffer[loc]-'0'; incr(k);
+ }
+ incr(loc);
+} while (mp->char_class[mp->buffer[loc]]==digit_class);
+f=mp_round_decimals(mp, k);
+if ( f==unity ) {
+ incr(n); f=0;
+}
+
+@ @<Pack the numeric and fraction parts of a numeric token and |return|@>=
+if ( n<32768 ) {
+ @<Set |cur_mod:=n*unity+f| and check if it is uncomfortably large@>;
+} else if ( mp->scanner_status!=tex_flushing ) {
+ print_err("Enormous number has been reduced");
+@.Enormous number...@>
+ help2("I can\'t handle numbers bigger than 32767.99998;",
+ "so I've changed your constant to that maximum amount.");
+ mp->deletions_allowed=false; mp_error(mp); mp->deletions_allowed=true;
+ mp->cur_mod=el_gordo;
+}
+mp->cur_cmd=numeric_token; return
+
+@ @<Set |cur_mod:=n*unity+f| and check if it is uncomfortably large@>=
+{
+ mp->cur_mod=n*unity+f;
+ if ( mp->cur_mod>=fraction_one ) {
+ if ( (mp->internal[mp_warning_check]>0) &&
+ (mp->scanner_status!=tex_flushing) ) {
+ print_err("Number is too large (");
+ mp_print_scaled(mp, mp->cur_mod);
+ mp_print_char(mp, xord(')'));
+ help3("It is at least 4096. Continue and I'll try to cope",
+ "with that big value; but it might be dangerous.",
+ "(Set warningcheck:=0 to suppress this message.)");
+ mp_error(mp);
+ }
+ }
+}
+
+@ Let's consider now what happens when |get_next| is looking at a token list.
+@^inner loop@>
+
+@<Input from token list;...@>=
+if ( loc>=mp->hi_mem_min ) { /* one-word token */
+ mp->cur_sym=mp_info(loc); loc=mp_link(loc); /* move to next */
+ if ( mp->cur_sym>=expr_base ) {
+ if ( mp->cur_sym>=suffix_base ) {
+ @<Insert a suffix or text parameter and |goto restart|@>;
+ } else {
+ mp->cur_cmd=capsule_token;
+ mp->cur_mod=mp->param_stack[param_start+mp->cur_sym-(expr_base)];
+ mp->cur_sym=0; return;
+ }
+ }
+} else if ( loc>null ) {
+ @<Get a stored numeric or string or capsule token and |return|@>
+} else { /* we are done with this token list */
+ mp_end_token_list(mp); goto RESTART; /* resume previous level */
+}
+
+@ @<Insert a suffix or text parameter...@>=
+{
+ if ( mp->cur_sym>=text_base ) mp->cur_sym=mp->cur_sym-mp->param_size;
+ /* |param_size=text_base-suffix_base| */
+ mp_begin_token_list(mp,
+ mp->param_stack[param_start+mp->cur_sym-(suffix_base)],
+ parameter);
+ goto RESTART;
+}
+
+@ @<Get a stored numeric or string or capsule token...@>=
+{
+ if ( mp_name_type(loc)==mp_token ) {
+ mp->cur_mod=value(loc);
+ if ( mp_type(loc)==mp_known ) {
+ mp->cur_cmd=numeric_token;
+ } else {
+ mp->cur_cmd=string_token; add_str_ref(mp->cur_mod);
+ }
+ } else {
+ mp->cur_mod=loc; mp->cur_cmd=capsule_token;
+ };
+ loc=mp_link(loc); return;
+}
+
+@ All of the easy branches of |get_next| have now been taken care of.
+There is one more branch.
+
+@<Move to next line of file, or |goto restart|...@>=
+if ( name>max_spec_src) {
+ @<Read next line of file into |buffer|, or
+ |goto restart| if the file has ended@>;
+} else {
+ if ( mp->input_ptr>0 ) {
+ /* text was inserted during error recovery or by \&{scantokens} */
+ mp_end_file_reading(mp); goto RESTART; /* resume previous level */
+ }
+ if (mp->job_name == NULL && ( mp->selector<log_only || mp->selector>=write_file))
+ mp_open_log_file(mp);
+ if ( mp->interaction>mp_nonstop_mode ) {
+ if ( limit==start ) /* previous line was empty */
+ mp_print_nl(mp, "(Please type a command or say `end')");
+@.Please type...@>
+ mp_print_ln(mp); mp->first=(size_t)start;
+ prompt_input("*"); /* input on-line into |buffer| */
+@.*\relax@>
+ limit=(halfword)mp->last; mp->buffer[limit]=xord('%');
+ mp->first=(size_t)(limit+1); loc=start;
+ } else {
+ mp_fatal_error(mp, "*** (job aborted, no legal end found)");
+@.job aborted@>
+ /* nonstop mode, which is intended for overnight batch processing,
+ never waits for on-line input */
+ }
+}
+
+@ The global variable |force_eof| is normally |false|; it is set |true|
+by an \&{endinput} command.
+
+@<Glob...@>=
+boolean force_eof; /* should the next \&{input} be aborted early? */
+
+@ We must decrement |loc| in order to leave the buffer in a valid state
+when an error condition causes us to |goto restart| without calling
+|end_file_reading|.
+
+@<Read next line of file into |buffer|, or
+ |goto restart| if the file has ended@>=
+{
+ incr(line); mp->first=(size_t)start;
+ if ( ! mp->force_eof ) {
+ if ( mp_input_ln(mp, cur_file ) ) /* not end of file */
+ mp_firm_up_the_line(mp); /* this sets |limit| */
+ else
+ mp->force_eof=true;
+ };
+ if ( mp->force_eof ) {
+ mp->force_eof=false;
+ decr(loc);
+ if ( mpx_reading ) {
+ @<Complain that the \.{MPX} file ended unexpectly; then set
+ |cur_sym:=frozen_mpx_break| and |goto comon_ending|@>;
+ } else {
+ mp_print_char(mp, xord(')')); decr(mp->open_parens);
+ update_terminal; /* show user that file has been read */
+ mp_end_file_reading(mp); /* resume previous level */
+ if ( mp_check_outer_validity(mp) ) goto RESTART;
+ else goto RESTART;
+ }
+ }
+ mp->buffer[limit]=xord('%'); mp->first=(size_t)(limit+1); loc=start; /* ready to read */
+}
+
+@ We should never actually come to the end of an \.{MPX} file because such
+files should have an \&{mpxbreak} after the translation of the last
+\&{btex}$\,\ldots\,$\&{etex} block.
+
+@<Complain that the \.{MPX} file ended unexpectly; then set...@>=
+{
+ mp->mpx_name[iindex]=mpx_finished;
+ print_err("mpx file ended unexpectedly");
+ help4("The file had too few picture expressions for btex...etex",
+ "blocks. Such files are normally generated automatically",
+ "but this one got messed up. You might want to insert a",
+ "picture expression now.");
+ mp->deletions_allowed=false; mp_error(mp); mp->deletions_allowed=true;
+ mp->cur_sym=frozen_mpx_break; goto COMMON_ENDING;
+}
+
+@ Sometimes we want to make it look as though we have just read a blank line
+without really doing so.
+
+@<Put an empty line in the input buffer@>=
+mp->last=mp->first; limit=(halfword)mp->last;
+ /* simulate |input_ln| and |firm_up_the_line| */
+mp->buffer[limit]=xord('%'); mp->first=(size_t)(limit+1); loc=start
+
+@ If the user has set the |mp_pausing| parameter to some positive value,
+and if nonstop mode has not been selected, each line of input is displayed
+on the terminal and the transcript file, followed by `\.{=>}'.
+\MP\ waits for a response. If the response is null (i.e., if nothing is
+typed except perhaps a few blank spaces), the original
+line is accepted as it stands; otherwise the line typed is
+used instead of the line in the file.
+
+@c void mp_firm_up_the_line (MP mp) {
+ size_t k; /* an index into |buffer| */
+ limit=(halfword)mp->last;
+ if ((!mp->noninteractive)
+ && (mp->internal[mp_pausing]>0 )
+ && (mp->interaction>mp_nonstop_mode )) {
+ wake_up_terminal; mp_print_ln(mp);
+ if ( start<limit ) {
+ for (k=(size_t)start;k<(size_t)limit;k++) {
+ mp_print_str(mp, mp->buffer[k]);
+ }
+ }
+ mp->first=(size_t)limit; prompt_input("=>"); /* wait for user response */
+@.=>@>
+ if ( mp->last>mp->first ) {
+ for (k=mp->first;k<mp->last;k++) { /* move line down in buffer */
+ mp->buffer[k+start-mp->first]=mp->buffer[k];
+ }
+ limit=(halfword)(start+mp->last-mp->first);
+ }
+ }
+}
+
+@* \[30] Dealing with \TeX\ material.
+The \&{btex}$\,\ldots\,$\&{etex} and \&{verbatimtex}$\,\ldots\,$\&{etex}
+features need to be implemented at a low level in the scanning process
+so that \MP\ can stay in synch with the a preprocessor that treats
+blocks of \TeX\ material as they occur in the input file without trying
+to expand \MP\ macros. Thus we need a special version of |get_next|
+that does not expand macros and such but does handle \&{btex},
+\&{verbatimtex}, etc.
+
+The special version of |get_next| is called |get_t_next|. It works by flushing
+\&{btex}$\,\ldots\,$\&{etex} and \&{verbatimtex}\allowbreak
+$\,\ldots\,$\&{etex} blocks, switching to the \.{MPX} file when it sees
+\&{btex}, and switching back when it sees \&{mpxbreak}.
+
+@d btex_code 0
+@d verbatim_code 1
+
+@ @<Put each...@>=
+mp_primitive(mp, "btex",start_tex,btex_code);
+@:btex_}{\&{btex} primitive@>
+mp_primitive(mp, "verbatimtex",start_tex,verbatim_code);
+@:verbatimtex_}{\&{verbatimtex} primitive@>
+mp_primitive(mp, "etex",etex_marker,0); mp->eqtb[frozen_etex]=mp->eqtb[mp->cur_sym];
+@:etex_}{\&{etex} primitive@>
+mp_primitive(mp, "mpxbreak",mpx_break,0); mp->eqtb[frozen_mpx_break]=mp->eqtb[mp->cur_sym];
+@:mpx_break_}{\&{mpxbreak} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case start_tex: if ( m==btex_code ) mp_print(mp, "btex");
+ else mp_print(mp, "verbatimtex"); break;
+case etex_marker: mp_print(mp, "etex"); break;
+case mpx_break: mp_print(mp, "mpxbreak"); break;
+
+@ Actually, |get_t_next| is a macro that avoids procedure overhead except
+in the unusual case where \&{btex}, \&{verbatimtex}, \&{etex}, or \&{mpxbreak}
+is encountered.
+
+@d get_t_next {mp_get_next(mp); if ( mp->cur_cmd<=max_pre_command ) mp_t_next(mp); }
+
+@<Declarations@>=
+static void mp_start_mpx_input (MP mp);
+
+@ @c
+static void mp_t_next (MP mp) {
+ int old_status; /* saves the |scanner_status| */
+ integer old_info; /* saves the |warning_info| */
+ while ( mp->cur_cmd<=max_pre_command ) {
+ if ( mp->cur_cmd==mpx_break ) {
+ if ( ! file_state || (mp->mpx_name[iindex]==absent) ) {
+ @<Complain about a misplaced \&{mpxbreak}@>;
+ } else {
+ mp_end_mpx_reading(mp);
+ goto TEX_FLUSH;
+ }
+ } else if ( mp->cur_cmd==start_tex ) {
+ if ( token_state || (name<=max_spec_src) ) {
+ @<Complain that we are not reading a file@>;
+ } else if ( mpx_reading ) {
+ @<Complain that \.{MPX} files cannot contain \TeX\ material@>;
+ } else if ( (mp->cur_mod!=verbatim_code)&&
+ (mp->mpx_name[iindex]!=mpx_finished) ) {
+ if ( ! mp_begin_mpx_reading(mp) ) mp_start_mpx_input(mp);
+ } else {
+ goto TEX_FLUSH;
+ }
+ } else {
+ @<Complain about a misplaced \&{etex}@>;
+ }
+ goto COMMON_ENDING;
+ TEX_FLUSH:
+ @<Flush the \TeX\ material@>;
+ COMMON_ENDING:
+ mp_get_next(mp);
+ }
+}
+
+@ We could be in the middle of an operation such as skipping false conditional
+text when \TeX\ material is encountered, so we must be careful to save the
+|scanner_status|.
+
+@<Flush the \TeX\ material@>=
+old_status=mp->scanner_status;
+old_info=mp->warning_info;
+mp->scanner_status=tex_flushing;
+mp->warning_info=line;
+do { mp_get_next(mp); } while (mp->cur_cmd!=etex_marker);
+mp->scanner_status=old_status;
+mp->warning_info=old_info
+
+@ @<Complain that \.{MPX} files cannot contain \TeX\ material@>=
+{ print_err("An mpx file cannot contain btex or verbatimtex blocks");
+help4("This file contains picture expressions for btex...etex",
+ "blocks. Such files are normally generated automatically",
+ "but this one seems to be messed up. I'll just keep going",
+ "and hope for the best.");
+mp_error(mp);
+}
+
+@ @<Complain that we are not reading a file@>=
+{ print_err("You can only use `btex' or `verbatimtex' in a file");
+help3("I'll have to ignore this preprocessor command because it",
+ "only works when there is a file to preprocess. You might",
+ "want to delete everything up to the next `etex`.");
+mp_error(mp);
+}
+
+@ @<Complain about a misplaced \&{mpxbreak}@>=
+{ print_err("Misplaced mpxbreak");
+help2("I'll ignore this preprocessor command because it",
+ "doesn't belong here");
+mp_error(mp);
+}
+
+@ @<Complain about a misplaced \&{etex}@>=
+{ print_err("Extra etex will be ignored");
+help1("There is no btex or verbatimtex for this to match");
+mp_error(mp);
+}
+
+@* \[31] Scanning macro definitions.
+\MP\ has a variety of ways to tuck tokens away into token lists for later
+use: Macros can be defined with \&{def}, \&{vardef}, \&{primarydef}, etc.;
+repeatable code can be defined with \&{for}, \&{forever}, \&{forsuffixes}.
+All such operations are handled by the routines in this part of the program.
+
+The modifier part of each command code is zero for the ``ending delimiters''
+like \&{enddef} and \&{endfor}.
+
+@d start_def 1 /* command modifier for \&{def} */
+@d var_def 2 /* command modifier for \&{vardef} */
+@d end_def 0 /* command modifier for \&{enddef} */
+@d start_forever 1 /* command modifier for \&{forever} */
+@d end_for 0 /* command modifier for \&{endfor} */
+
+@<Put each...@>=
+mp_primitive(mp, "def",macro_def,start_def);
+@:def_}{\&{def} primitive@>
+mp_primitive(mp, "vardef",macro_def,var_def);
+@:var_def_}{\&{vardef} primitive@>
+mp_primitive(mp, "primarydef",macro_def,secondary_primary_macro);
+@:primary_def_}{\&{primarydef} primitive@>
+mp_primitive(mp, "secondarydef",macro_def,tertiary_secondary_macro);
+@:secondary_def_}{\&{secondarydef} primitive@>
+mp_primitive(mp, "tertiarydef",macro_def,expression_tertiary_macro);
+@:tertiary_def_}{\&{tertiarydef} primitive@>
+mp_primitive(mp, "enddef",macro_def,end_def); mp->eqtb[frozen_end_def]=mp->eqtb[mp->cur_sym];
+@:end_def_}{\&{enddef} primitive@>
+@#
+mp_primitive(mp, "for",iteration,expr_base);
+@:for_}{\&{for} primitive@>
+mp_primitive(mp, "forsuffixes",iteration,suffix_base);
+@:for_suffixes_}{\&{forsuffixes} primitive@>
+mp_primitive(mp, "forever",iteration,start_forever);
+@:forever_}{\&{forever} primitive@>
+mp_primitive(mp, "endfor",iteration,end_for); mp->eqtb[frozen_end_for]=mp->eqtb[mp->cur_sym];
+@:end_for_}{\&{endfor} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case macro_def:
+ if ( m<=var_def ) {
+ if ( m==start_def ) mp_print(mp, "def");
+ else if ( m<start_def ) mp_print(mp, "enddef");
+ else mp_print(mp, "vardef");
+ } else if ( m==secondary_primary_macro ) {
+ mp_print(mp, "primarydef");
+ } else if ( m==tertiary_secondary_macro ) {
+ mp_print(mp, "secondarydef");
+ } else {
+ mp_print(mp, "tertiarydef");
+ }
+ break;
+case iteration:
+ if ( m<=start_forever ) {
+ if ( m==start_forever ) mp_print(mp, "forever");
+ else mp_print(mp, "endfor");
+ } else if ( m==expr_base ) {
+ mp_print(mp, "for");
+ } else {
+ mp_print(mp, "forsuffixes");
+ }
+ break;
+
+@ Different macro-absorbing operations have different syntaxes, but they
+also have a lot in common. There is a list of special symbols that are to
+be replaced by parameter tokens; there is a special command code that
+ends the definition; the quotation conventions are identical. Therefore
+it makes sense to have most of the work done by a single subroutine. That
+subroutine is called |scan_toks|.
+
+The first parameter to |scan_toks| is the command code that will
+terminate scanning (either |macro_def| or |iteration|).
+
+The second parameter, |subst_list|, points to a (possibly empty) list
+of two-word nodes whose |info| and |value| fields specify symbol tokens
+before and after replacement. The list will be returned to free storage
+by |scan_toks|.
+
+The third parameter is simply appended to the token list that is built.
+And the final parameter tells how many of the special operations
+\.{\#\AT!}, \.{\AT!}, and \.{\AT!\#} are to be replaced by suffix parameters.
+When such parameters are present, they are called \.{(SUFFIX0)},
+\.{(SUFFIX1)}, and \.{(SUFFIX2)}.
+
+@c static pointer mp_scan_toks (MP mp,command_code terminator, pointer
+ subst_list, pointer tail_end, quarterword suffix_count) {
+ pointer p; /* tail of the token list being built */
+ pointer q; /* temporary for link management */
+ integer balance; /* left delimiters minus right delimiters */
+ p=hold_head; balance=1; mp_link(hold_head)=null;
+ while (1) {
+ get_t_next;
+ if ( mp->cur_sym>0 ) {
+ @<Substitute for |cur_sym|, if it's on the |subst_list|@>;
+ if ( mp->cur_cmd==terminator ) {
+ @<Adjust the balance; |break| if it's zero@>;
+ } else if ( mp->cur_cmd==macro_special ) {
+ @<Handle quoted symbols, \.{\#\AT!}, \.{\AT!}, or \.{\AT!\#}@>;
+ }
+ }
+ mp_link(p)=mp_cur_tok(mp); p=mp_link(p);
+ }
+ mp_link(p)=tail_end; mp_flush_node_list(mp, subst_list);
+ return mp_link(hold_head);
+}
+
+@ @<Substitute for |cur_sym|...@>=
+{
+ q=subst_list;
+ while ( q!=null ) {
+ if ( mp_info(q)==mp->cur_sym ) {
+ mp->cur_sym=value(q); mp->cur_cmd=relax; break;
+ }
+ q=mp_link(q);
+ }
+}
+
+@ @<Adjust the balance; |break| if it's zero@>=
+if ( mp->cur_mod>0 ) {
+ incr(balance);
+} else {
+ decr(balance);
+ if ( balance==0 )
+ break;
+}
+
+@ Four commands are intended to be used only within macro texts: \&{quote},
+\.{\#\AT!}, \.{\AT!}, and \.{\AT!\#}. They are variants of a single command
+code called |macro_special|.
+
+@d quote 0 /* |macro_special| modifier for \&{quote} */
+@d macro_prefix 1 /* |macro_special| modifier for \.{\#\AT!} */
+@d macro_at 2 /* |macro_special| modifier for \.{\AT!} */
+@d macro_suffix 3 /* |macro_special| modifier for \.{\AT!\#} */
+
+@<Put each...@>=
+mp_primitive(mp, "quote",macro_special,quote);
+@:quote_}{\&{quote} primitive@>
+mp_primitive(mp, "#@@",macro_special,macro_prefix);
+@:]]]\#\AT!_}{\.{\#\AT!} primitive@>
+mp_primitive(mp, "@@",macro_special,macro_at);
+@:]]]\AT!_}{\.{\AT!} primitive@>
+mp_primitive(mp, "@@#",macro_special,macro_suffix);
+@:]]]\AT!\#_}{\.{\AT!\#} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case macro_special:
+ switch (m) {
+ case macro_prefix: mp_print(mp, "#@@"); break;
+ case macro_at: mp_print_char(mp, xord('@@')); break;
+ case macro_suffix: mp_print(mp, "@@#"); break;
+ default: mp_print(mp, "quote"); break;
+ }
+ break;
+
+@ @<Handle quoted...@>=
+{
+ if ( mp->cur_mod==quote ) { get_t_next; }
+ else if ( mp->cur_mod<=suffix_count )
+ mp->cur_sym=suffix_base-1+mp->cur_mod;
+}
+
+@ Here is a routine that's used whenever a token will be redefined. If
+the user's token is unredefinable, the `|frozen_inaccessible|' token is
+substituted; the latter is redefinable but essentially impossible to use,
+hence \MP's tables won't get fouled up.
+
+@c static void mp_get_symbol (MP mp) { /* sets |cur_sym| to a safe symbol */
+RESTART:
+ get_t_next;
+ if ( (mp->cur_sym==0)||(mp->cur_sym>(integer)frozen_inaccessible) ) {
+ print_err("Missing symbolic token inserted");
+@.Missing symbolic token...@>
+ help3("Sorry: You can\'t redefine a number, string, or expr.",
+ "I've inserted an inaccessible symbol so that your",
+ "definition will be completed without mixing me up too badly.");
+ if ( mp->cur_sym>0 )
+ mp->help_line[2]="Sorry: You can\'t redefine my error-recovery tokens.";
+ else if ( mp->cur_cmd==string_token )
+ delete_str_ref(mp->cur_mod);
+ mp->cur_sym=frozen_inaccessible; mp_ins_error(mp); goto RESTART;
+ }
+}
+
+@ Before we actually redefine a symbolic token, we need to clear away its
+former value, if it was a variable. The following stronger version of
+|get_symbol| does that.
+
+@c static void mp_get_clear_symbol (MP mp) {
+ mp_get_symbol(mp); mp_clear_symbol(mp, mp->cur_sym,false);
+}
+
+@ Here's another little subroutine; it checks that an equals sign
+or assignment sign comes along at the proper place in a macro definition.
+
+@c static void mp_check_equals (MP mp) {
+ if ( mp->cur_cmd!=equals ) if ( mp->cur_cmd!=assignment ) {
+ mp_missing_err(mp, "=");
+@.Missing `='@>
+ help5("The next thing in this `def' should have been `=',",
+ "because I've already looked at the definition heading.",
+ "But don't worry; I'll pretend that an equals sign",
+ "was present. Everything from here to `enddef'",
+ "will be the replacement text of this macro.");
+ mp_back_error(mp);
+ }
+}
+
+@ A \&{primarydef}, \&{secondarydef}, or \&{tertiarydef} is rather easily
+handled now that we have |scan_toks|. In this case there are
+two parameters, which will be \.{EXPR0} and \.{EXPR1} (i.e.,
+|expr_base| and |expr_base+1|).
+
+@c static void mp_make_op_def (MP mp) {
+ command_code m; /* the type of definition */
+ pointer p,q,r; /* for list manipulation */
+ m=mp->cur_mod;
+ mp_get_symbol(mp); q=mp_get_node(mp, token_node_size);
+ mp_info(q)=mp->cur_sym; value(q)=expr_base;
+ mp_get_clear_symbol(mp); mp->warning_info=mp->cur_sym;
+ mp_get_symbol(mp); p=mp_get_node(mp, token_node_size);
+ mp_info(p)=mp->cur_sym; value(p)=expr_base+1; mp_link(p)=q;
+ get_t_next; mp_check_equals(mp);
+ mp->scanner_status=op_defining; q=mp_get_avail(mp); ref_count(q)=null;
+ r=mp_get_avail(mp); mp_link(q)=r; mp_info(r)=general_macro;
+ mp_link(r)=mp_scan_toks(mp, macro_def,p,null,0);
+ mp->scanner_status=normal; eq_type(mp->warning_info)=m;
+ equiv(mp->warning_info)=q; mp_get_x_next(mp);
+}
+
+@ Parameters to macros are introduced by the keywords \&{expr},
+\&{suffix}, \&{text}, \&{primary}, \&{secondary}, and \&{tertiary}.
+
+@<Put each...@>=
+mp_primitive(mp, "expr",param_type,expr_base);
+@:expr_}{\&{expr} primitive@>
+mp_primitive(mp, "suffix",param_type,suffix_base);
+@:suffix_}{\&{suffix} primitive@>
+mp_primitive(mp, "text",param_type,text_base);
+@:text_}{\&{text} primitive@>
+mp_primitive(mp, "primary",param_type,primary_macro);
+@:primary_}{\&{primary} primitive@>
+mp_primitive(mp, "secondary",param_type,secondary_macro);
+@:secondary_}{\&{secondary} primitive@>
+mp_primitive(mp, "tertiary",param_type,tertiary_macro);
+@:tertiary_}{\&{tertiary} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case param_type:
+ if ( m>=expr_base ) {
+ if ( m==expr_base ) mp_print(mp, "expr");
+ else if ( m==suffix_base ) mp_print(mp, "suffix");
+ else mp_print(mp, "text");
+ } else if ( m<secondary_macro ) {
+ mp_print(mp, "primary");
+ } else if ( m==secondary_macro ) {
+ mp_print(mp, "secondary");
+ } else {
+ mp_print(mp, "tertiary");
+ }
+ break;
+
+@ Let's turn next to the more complex processing associated with \&{def}
+and \&{vardef}. When the following procedure is called, |cur_mod|
+should be either |start_def| or |var_def|.
+
+@c
+static void mp_scan_def (MP mp) {
+ int m; /* the type of definition */
+ int n; /* the number of special suffix parameters */
+ int k; /* the total number of parameters */
+ int c; /* the kind of macro we're defining */
+ pointer r; /* parameter-substitution list */
+ pointer q; /* tail of the macro token list */
+ pointer p; /* temporary storage */
+ halfword base; /* |expr_base|, |suffix_base|, or |text_base| */
+ pointer l_delim,r_delim; /* matching delimiters */
+ m=mp->cur_mod; c=general_macro; mp_link(hold_head)=null;
+ q=mp_get_avail(mp); ref_count(q)=null; r=null;
+ @<Scan the token or variable to be defined;
+ set |n|, |scanner_status|, and |warning_info|@>;
+ k=n;
+ if ( mp->cur_cmd==left_delimiter ) {
+ @<Absorb delimited parameters, putting them into lists |q| and |r|@>;
+ }
+ if ( mp->cur_cmd==param_type ) {
+ @<Absorb undelimited parameters, putting them into list |r|@>;
+ }
+ mp_check_equals(mp);
+ p=mp_get_avail(mp); mp_info(p)=c; mp_link(q)=p;
+ @<Attach the replacement text to the tail of node |p|@>;
+ mp->scanner_status=normal; mp_get_x_next(mp);
+}
+
+@ We don't put `|frozen_end_group|' into the replacement text of
+a \&{vardef}, because the user may want to redefine `\.{endgroup}'.
+
+@<Attach the replacement text to the tail of node |p|@>=
+if ( m==start_def ) {
+ mp_link(p)=mp_scan_toks(mp, macro_def,r,null,n);
+} else {
+ q=mp_get_avail(mp); mp_info(q)=mp->bg_loc; mp_link(p)=q;
+ p=mp_get_avail(mp); mp_info(p)=mp->eg_loc;
+ mp_link(q)=mp_scan_toks(mp, macro_def,r,p,n);
+}
+if ( mp->warning_info==bad_vardef )
+ mp_flush_token_list(mp, value(bad_vardef))
+
+@ @<Glob...@>=
+int bg_loc;
+int eg_loc; /* hash addresses of `\.{begingroup}' and `\.{endgroup}' */
+
+@ @<Scan the token or variable to be defined;...@>=
+if ( m==start_def ) {
+ mp_get_clear_symbol(mp); mp->warning_info=mp->cur_sym; get_t_next;
+ mp->scanner_status=op_defining; n=0;
+ eq_type(mp->warning_info)=defined_macro; equiv(mp->warning_info)=q;
+} else {
+ p=mp_scan_declared_variable(mp);
+ mp_flush_variable(mp, equiv(mp_info(p)),mp_link(p),true);
+ mp->warning_info=mp_find_variable(mp, p); mp_flush_list(mp, p);
+ if ( mp->warning_info==null ) @<Change to `\.{a bad variable}'@>;
+ mp->scanner_status=var_defining; n=2;
+ if ( mp->cur_cmd==macro_special ) if ( mp->cur_mod==macro_suffix ) {/* \.{\AT!\#} */
+ n=3; get_t_next;
+ }
+ mp_type(mp->warning_info)=mp_unsuffixed_macro-2+n; value(mp->warning_info)=q;
+} /* |mp_suffixed_macro=mp_unsuffixed_macro+1| */
+
+@ @<Change to `\.{a bad variable}'@>=
+{
+ print_err("This variable already starts with a macro");
+@.This variable already...@>
+ help2("After `vardef a' you can\'t say `vardef a.b'.",
+ "So I'll have to discard this definition.");
+ mp_error(mp); mp->warning_info=bad_vardef;
+}
+
+@ @<Initialize table entries...@>=
+mp_name_type(bad_vardef)=mp_root; mp_link(bad_vardef)=frozen_bad_vardef;
+equiv(frozen_bad_vardef)=bad_vardef; eq_type(frozen_bad_vardef)=tag_token;
+
+@ @<Absorb delimited parameters, putting them into lists |q| and |r|@>=
+do {
+ l_delim=mp->cur_sym; r_delim=mp->cur_mod; get_t_next;
+ if ( (mp->cur_cmd==param_type)&&(mp->cur_mod>=expr_base) ) {
+ base=mp->cur_mod;
+ } else {
+ print_err("Missing parameter type; `expr' will be assumed");
+@.Missing parameter type@>
+ help1("You should've had `expr' or `suffix' or `text' here.");
+ mp_back_error(mp); base=expr_base;
+ }
+ @<Absorb parameter tokens for type |base|@>;
+ mp_check_delimiter(mp, l_delim,r_delim);
+ get_t_next;
+} while (mp->cur_cmd==left_delimiter)
+
+@ @<Absorb parameter tokens for type |base|@>=
+do {
+ mp_link(q)=mp_get_avail(mp); q=mp_link(q); mp_info(q)=base+k;
+ mp_get_symbol(mp); p=mp_get_node(mp, token_node_size);
+ value(p)=base+k; mp_info(p)=mp->cur_sym;
+ if ( k==mp->param_size ) mp_overflow(mp, "parameter stack size",mp->param_size);
+@:MetaPost capacity exceeded parameter stack size}{\quad parameter stack size@>
+ incr(k); mp_link(p)=r; r=p; get_t_next;
+} while (mp->cur_cmd==comma)
+
+@ @<Absorb undelimited parameters, putting them into list |r|@>=
+{
+ p=mp_get_node(mp, token_node_size);
+ if ( mp->cur_mod<expr_base ) {
+ c=mp->cur_mod; value(p)=expr_base+k;
+ } else {
+ value(p)=mp->cur_mod+k;
+ if ( mp->cur_mod==expr_base ) c=expr_macro;
+ else if ( mp->cur_mod==suffix_base ) c=suffix_macro;
+ else c=text_macro;
+ }
+ if ( k==mp->param_size ) mp_overflow(mp, "parameter stack size",mp->param_size);
+ incr(k); mp_get_symbol(mp); mp_info(p)=mp->cur_sym; mp_link(p)=r; r=p; get_t_next;
+ if ( c==expr_macro ) if ( mp->cur_cmd==of_token ) {
+ c=of_macro; p=mp_get_node(mp, token_node_size);
+ if ( k==mp->param_size ) mp_overflow(mp, "parameter stack size",mp->param_size);
+ value(p)=expr_base+k; mp_get_symbol(mp); mp_info(p)=mp->cur_sym;
+ mp_link(p)=r; r=p; get_t_next;
+ }
+}
+
+@* \[32] Expanding the next token.
+Only a few command codes |<min_command| can possibly be returned by
+|get_t_next|; in increasing order, they are
+|if_test|, |fi_or_else|, |input|, |iteration|, |repeat_loop|,
+|exit_test|, |relax|, |scan_tokens|, |expand_after|, and |defined_macro|.
+
+\MP\ usually gets the next token of input by saying |get_x_next|. This is
+like |get_t_next| except that it keeps getting more tokens until
+finding |cur_cmd>=min_command|. In other words, |get_x_next| expands
+macros and removes conditionals or iterations or input instructions that
+might be present.
+
+It follows that |get_x_next| might invoke itself recursively. In fact,
+there is massive recursion, since macro expansion can involve the
+scanning of arbitrarily complex expressions, which in turn involve
+macro expansion and conditionals, etc.
+@^recursion@>
+
+Therefore it's necessary to declare a whole bunch of |forward|
+procedures at this point, and to insert some other procedures
+that will be invoked by |get_x_next|.
+
+@<Declarations@>=
+static void mp_scan_primary (MP mp);
+static void mp_scan_secondary (MP mp);
+static void mp_scan_tertiary (MP mp);
+static void mp_scan_expression (MP mp);
+static void mp_scan_suffix (MP mp);
+static void mp_get_boolean (MP mp);
+static void mp_pass_text (MP mp);
+static void mp_conditional (MP mp);
+static void mp_start_input (MP mp);
+static void mp_begin_iteration (MP mp);
+static void mp_resume_iteration (MP mp);
+static void mp_stop_iteration (MP mp);
+
+@ An auxiliary subroutine called |expand| is used by |get_x_next|
+when it has to do exotic expansion commands.
+
+@c
+static void mp_expand (MP mp) {
+ pointer p; /* for list manipulation */
+ size_t k; /* something that we hope is |<=buf_size| */
+ pool_pointer j; /* index into |str_pool| */
+ if ( mp->internal[mp_tracing_commands]>unity )
+ if ( mp->cur_cmd!=defined_macro )
+ show_cur_cmd_mod;
+ switch (mp->cur_cmd) {
+ case if_test:
+ mp_conditional(mp); /* this procedure is discussed in Part 36 below */
+ break;
+ case fi_or_else:
+ @<Terminate the current conditional and skip to \&{fi}@>;
+ break;
+ case input:
+ @<Initiate or terminate input from a file@>;
+ break;
+ case iteration:
+ if ( mp->cur_mod==end_for ) {
+ @<Scold the user for having an extra \&{endfor}@>;
+ } else {
+ mp_begin_iteration(mp); /* this procedure is discussed in Part 37 below */
+ }
+ break;
+ case repeat_loop:
+ @<Repeat a loop@>;
+ break;
+ case exit_test:
+ @<Exit a loop if the proper time has come@>;
+ break;
+ case relax:
+ break;
+ case expand_after:
+ @<Expand the token after the next token@>;
+ break;
+ case scan_tokens:
+ @<Put a string into the input buffer@>;
+ break;
+ case defined_macro:
+ mp_macro_call(mp, mp->cur_mod,null,mp->cur_sym);
+ break;
+ }; /* there are no other cases */
+}
+
+@ @<Scold the user...@>=
+{
+ print_err("Extra `endfor'");
+@.Extra `endfor'@>
+ help2("I'm not currently working on a for loop,",
+ "so I had better not try to end anything.");
+ mp_error(mp);
+}
+
+@ The processing of \&{input} involves the |start_input| subroutine,
+which will be declared later; the processing of \&{endinput} is trivial.
+
+@<Put each...@>=
+mp_primitive(mp, "input",input,0);
+@:input_}{\&{input} primitive@>
+mp_primitive(mp, "endinput",input,1);
+@:end_input_}{\&{endinput} primitive@>
+
+@ @<Cases of |print_cmd_mod|...@>=
+case input:
+ if ( m==0 ) mp_print(mp, "input");
+ else mp_print(mp, "endinput");
+ break;
+
+@ @<Initiate or terminate input...@>=
+if ( mp->cur_mod>0 ) mp->force_eof=true;
+else mp_start_input(mp)
+
+@ We'll discuss the complicated parts of loop operations later. For now
+it suffices to know that there's a global variable called |loop_ptr|
+that will be |null| if no loop is in progress.
+
+@<Repeat a loop@>=
+{ while ( token_state &&(loc==null) )
+ mp_end_token_list(mp); /* conserve stack space */
+ if ( mp->loop_ptr==null ) {
+ print_err("Lost loop");
+@.Lost loop@>
+ help2("I'm confused; after exiting from a loop, I still seem",
+ "to want to repeat it. I'll try to forget the problem.");
+ mp_error(mp);
+ } else {
+ mp_resume_iteration(mp); /* this procedure is in Part 37 below */
+ }
+}
+
+@ @<Exit a loop if the proper time has come@>=
+{ mp_get_boolean(mp);
+ if ( mp->internal[mp_tracing_commands]>unity )
+ mp_show_cmd_mod(mp, nullary,mp->cur_exp);
+ if ( mp->cur_exp==true_code ) {
+ if ( mp->loop_ptr==null ) {
+ print_err("No loop is in progress");
+@.No loop is in progress@>
+ help1("Why say `exitif' when there's nothing to exit from?");
+ if ( mp->cur_cmd==semicolon ) mp_error(mp); else mp_back_error(mp);
+ } else {
+ @<Exit prematurely from an iteration@>;
+ }
+ } else if ( mp->cur_cmd!=semicolon ) {
+ mp_missing_err(mp, ";");
+@.Missing `;'@>
+ help2("After `exitif <boolean exp>' I expect to see a semicolon.",
+ "I shall pretend that one was there."); mp_back_error(mp);
+ }
+}
+
+@ Here we use the fact that |forever_text| is the only |token_type| that
+is less than |loop_text|.
+
+@<Exit prematurely...@>=
+{ p=null;
+ do {
+ if ( file_state ) {
+ mp_end_file_reading(mp);
+ } else {
+ if ( token_type<=loop_text ) p=start;
+ mp_end_token_list(mp);
+ }
+ } while (p==null);
+ if ( p!=mp_info(mp->loop_ptr) ) mp_fatal_error(mp, "*** (loop confusion)");
+@.loop confusion@>
+ mp_stop_iteration(mp); /* this procedure is in Part 34 below */
+}
+
+@ @<Expand the token after the next token@>=
+{ get_t_next;
+ p=mp_cur_tok(mp); get_t_next;
+ if ( mp->cur_cmd<min_command ) mp_expand(mp);
+ else mp_back_input(mp);
+ back_list(p);
+}
+
+@ @<Put a string into the input buffer@>=
+{ mp_get_x_next(mp); mp_scan_primary(mp);
+ if ( mp->cur_type!=mp_string_type ) {
+ mp_disp_err(mp, null,"Not a string");
+@.Not a string@>
+ help2("I'm going to flush this expression, since",
+ "scantokens should be followed by a known string.");
+ mp_put_get_flush_error(mp, 0);
+ } else {
+ mp_back_input(mp);
+ if ( length(mp->cur_exp)>0 )
+ @<Pretend we're reading a new one-line file@>;
+ }
+}
+
+@ @<Pretend we're reading a new one-line file@>=
+{ mp_begin_file_reading(mp); name=is_scantok;
+ k=mp->first+length(mp->cur_exp);
+ if ( k>=mp->max_buf_stack ) {
+ while ( k>=mp->buf_size ) {
+ mp_reallocate_buffer(mp,(mp->buf_size+(mp->buf_size/4)));
+ }
+ mp->max_buf_stack=k+1;
+ }
+ j=mp->str_start[mp->cur_exp]; limit=(halfword)k;
+ while ( mp->first<(size_t)limit ) {
+ mp->buffer[mp->first]=mp->str_pool[j]; incr(j); incr(mp->first);
+ }
+ mp->buffer[limit]=xord('%'); mp->first=(size_t)(limit+1); loc=start;
+ mp_flush_cur_exp(mp, 0);
+}
+
+@ Here finally is |get_x_next|.
+
+The expression scanning routines to be considered later
+communicate via the global quantities |cur_type| and |cur_exp|;
+we must be very careful to save and restore these quantities while
+macros are being expanded.
+@^inner loop@>
+
+@<Declarations@>=
+static void mp_get_x_next (MP mp);
+
+@ @c void mp_get_x_next (MP mp) {
+ pointer save_exp; /* a capsule to save |cur_type| and |cur_exp| */
+ get_t_next;
+ if ( mp->cur_cmd<min_command ) {
+ save_exp=mp_stash_cur_exp(mp);
+ do {
+ if ( mp->cur_cmd==defined_macro )
+ mp_macro_call(mp, mp->cur_mod,null,mp->cur_sym);
+ else
+ mp_expand(mp);
+ get_t_next;
+ } while (mp->cur_cmd<min_command);
+ mp_unstash_cur_exp(mp, save_exp); /* that restores |cur_type| and |cur_exp| */
+ }
+}
+
+@ Now let's consider the |macro_call| procedure, which is used to start up
+all user-defined macros. Since the arguments to a macro might be expressions,
+|macro_call| is recursive.
+@^recursion@>
+
+The first parameter to |macro_call| points to the reference count of the
+token list that defines the macro. The second parameter contains any
+arguments that have already been parsed (see below). The third parameter
+points to the symbolic token that names the macro. If the third parameter
+is |null|, the macro was defined by \&{vardef}, so its name can be
+reconstructed from the prefix and ``at'' arguments found within the
+second parameter.
+
+What is this second parameter? It's simply a linked list of one-word items,
+whose |info| fields point to the arguments. In other words, if |arg_list=null|,
+no arguments have been scanned yet; otherwise |mp_info(arg_list)| points to
+the first scanned argument, and |mp_link(arg_list)| points to the list of
+further arguments (if any).
+
+Arguments of type \&{expr} are so-called capsules, which we will
+discuss later when we concentrate on expressions; they can be
+recognized easily because their |link| field is |void|. Arguments of type
+\&{suffix} and \&{text} are token lists without reference counts.
+
+@ After argument scanning is complete, the arguments are moved to the
+|param_stack|. (They can't be put on that stack any sooner, because
+the stack is growing and shrinking in unpredictable ways as more arguments
+are being acquired.) Then the macro body is fed to the scanner; i.e.,
+the replacement text of the macro is placed at the top of the \MP's
+input stack, so that |get_t_next| will proceed to read it next.
+
+@<Declarations@>=
+static void mp_macro_call (MP mp,pointer def_ref, pointer arg_list,
+ pointer macro_name) ;
+
+@ @c
+void mp_macro_call (MP mp,pointer def_ref, pointer arg_list,
+ pointer macro_name) {
+ /* invokes a user-defined control sequence */
+ pointer r; /* current node in the macro's token list */
+ pointer p,q; /* for list manipulation */
+ integer n; /* the number of arguments */
+ pointer tail = 0; /* tail of the argument list */
+ pointer l_delim=0,r_delim=0; /* a delimiter pair */
+ r=mp_link(def_ref); add_mac_ref(def_ref);
+ if ( arg_list==null ) {
+ n=0;
+ } else {
+ @<Determine the number |n| of arguments already supplied,
+ and set |tail| to the tail of |arg_list|@>;
+ }
+ if ( mp->internal[mp_tracing_macros]>0 ) {
+ @<Show the text of the macro being expanded, and the existing arguments@>;
+ }
+ @<Scan the remaining arguments, if any; set |r| to the first token
+ of the replacement text@>;
+ @<Feed the arguments and replacement text to the scanner@>;
+}
+
+@ @<Show the text of the macro...@>=
+mp_begin_diagnostic(mp); mp_print_ln(mp);
+mp_print_macro_name(mp, arg_list,macro_name);
+if ( n==3 ) mp_print(mp, "@@#"); /* indicate a suffixed macro */
+mp_show_macro(mp, def_ref,null,100000);
+if ( arg_list!=null ) {
+ n=0; p=arg_list;
+ do {
+ q=mp_info(p);
+ mp_print_arg(mp, q,n,0);
+ incr(n); p=mp_link(p);
+ } while (p!=null);
+}
+mp_end_diagnostic(mp, false)
+
+
+@ @<Declarations@>=
+static void mp_print_macro_name (MP mp,pointer a, pointer n);
+
+@ @c
+void mp_print_macro_name (MP mp,pointer a, pointer n) {
+ pointer p,q; /* they traverse the first part of |a| */
+ if ( n!=null ) {
+ mp_print_text(n);
+ } else {
+ p=mp_info(a);
+ if ( p==null ) {
+ mp_print_text(mp_info(mp_info(mp_link(a))));
+ } else {
+ q=p;
+ while ( mp_link(q)!=null ) q=mp_link(q);
+ mp_link(q)=mp_info(mp_link(a));
+ mp_show_token_list(mp, p,null,1000,0);
+ mp_link(q)=null;
+ }
+ }
+}
+
+@ @<Declarations@>=
+static void mp_print_arg (MP mp,pointer q, integer n, pointer b) ;
+
+@ @c
+void mp_print_arg (MP mp,pointer q, integer n, pointer b) {
+ if ( mp_link(q)==mp_void ) mp_print_nl(mp, "(EXPR");
+ else if ( (b<text_base)&&(b!=text_macro) ) mp_print_nl(mp, "(SUFFIX");
+ else mp_print_nl(mp, "(TEXT");
+ mp_print_int(mp, n); mp_print(mp, ")<-");
+ if ( mp_link(q)==mp_void ) mp_print_exp(mp, q,1);
+ else mp_show_token_list(mp, q,null,1000,0);
+}
+
+@ @<Determine the number |n| of arguments already supplied...@>=
+{
+ n=1; tail=arg_list;
+ while ( mp_link(tail)!=null ) {
+ incr(n); tail=mp_link(tail);
+ }
+}
+
+@ @<Scan the remaining arguments, if any; set |r|...@>=
+mp->cur_cmd=comma+1; /* anything |<>comma| will do */
+while ( mp_info(r)>=expr_base ) {
+ @<Scan the delimited argument represented by |mp_info(r)|@>;
+ r=mp_link(r);
+}
+if ( mp->cur_cmd==comma ) {
+ print_err("Too many arguments to ");
+@.Too many arguments...@>
+ mp_print_macro_name(mp, arg_list,macro_name); mp_print_char(mp, xord(';'));
+ mp_print_nl(mp, " Missing `"); mp_print_text(r_delim);
+@.Missing `)'...@>
+ mp_print(mp, "' has been inserted");
+ help3("I'm going to assume that the comma I just read was a",
+ "right delimiter, and then I'll begin expanding the macro.",
+ "You might want to delete some tokens before continuing.");
+ mp_error(mp);
+}
+if ( mp_info(r)!=general_macro ) {
+ @<Scan undelimited argument(s)@>;
+}
+r=mp_link(r)
+
+@ At this point, the reader will find it advisable to review the explanation
+of token list format that was presented earlier, paying special attention to
+the conventions that apply only at the beginning of a macro's token list.
+
+On the other hand, the reader will have to take the expression-parsing
+aspects of the following program on faith; we will explain |cur_type|
+and |cur_exp| later. (Several things in this program depend on each other,
+and it's necessary to jump into the circle somewhere.)
+
+@<Scan the delimited argument represented by |mp_info(r)|@>=
+if ( mp->cur_cmd!=comma ) {
+ mp_get_x_next(mp);
+ if ( mp->cur_cmd!=left_delimiter ) {
+ print_err("Missing argument to ");
+@.Missing argument...@>
+ mp_print_macro_name(mp, arg_list,macro_name);
+ help3("That macro has more parameters than you thought.",
+ "I'll continue by pretending that each missing argument",
+ "is either zero or null.");
+ if ( mp_info(r)>=suffix_base ) {
+ mp->cur_exp=null; mp->cur_type=mp_token_list;
+ } else {
+ mp->cur_exp=0; mp->cur_type=mp_known;
+ }
+ mp_back_error(mp); mp->cur_cmd=right_delimiter;
+ goto FOUND;
+ }
+ l_delim=mp->cur_sym; r_delim=mp->cur_mod;
+}
+@<Scan the argument represented by |mp_info(r)|@>;
+if ( mp->cur_cmd!=comma )
+ @<Check that the proper right delimiter was present@>;
+FOUND:
+@<Append the current expression to |arg_list|@>
+
+@ @<Check that the proper right delim...@>=
+if ( (mp->cur_cmd!=right_delimiter)||(mp->cur_mod!=l_delim) ) {
+ if ( mp_info(mp_link(r))>=expr_base ) {
+ mp_missing_err(mp, ",");
+@.Missing `,'@>
+ help3("I've finished reading a macro argument and am about to",
+ "read another; the arguments weren't delimited correctly.",
+ "You might want to delete some tokens before continuing.");
+ mp_back_error(mp); mp->cur_cmd=comma;
+ } else {
+ mp_missing_err(mp, str(text(r_delim)));
+@.Missing `)'@>
+ help2("I've gotten to the end of the macro parameter list.",
+ "You might want to delete some tokens before continuing.");
+ mp_back_error(mp);
+ }
+}
+
+@ A \&{suffix} or \&{text} parameter will have been scanned as
+a token list pointed to by |cur_exp|, in which case we will have
+|cur_type=token_list|.
+
+@<Append the current expression to |arg_list|@>=
+{
+ p=mp_get_avail(mp);
+ if ( mp->cur_type==mp_token_list ) mp_info(p)=mp->cur_exp;
+ else mp_info(p)=mp_stash_cur_exp(mp);
+ if ( mp->internal[mp_tracing_macros]>0 ) {
+ mp_begin_diagnostic(mp); mp_print_arg(mp, mp_info(p),n,mp_info(r));
+ mp_end_diagnostic(mp, false);
+ }
+ if ( arg_list==null ) arg_list=p;
+ else mp_link(tail)=p;
+ tail=p; incr(n);
+}
+
+@ @<Scan the argument represented by |mp_info(r)|@>=
+if ( mp_info(r)>=text_base ) {
+ mp_scan_text_arg(mp, l_delim,r_delim);
+} else {
+ mp_get_x_next(mp);
+ if ( mp_info(r)>=suffix_base ) mp_scan_suffix(mp);
+ else mp_scan_expression(mp);
+}
+
+@ The parameters to |scan_text_arg| are either a pair of delimiters
+or zero; the latter case is for undelimited text arguments, which
+end with the first semicolon or \&{endgroup} or \&{end} that is not
+contained in a group.
+
+@<Declarations@>=
+static void mp_scan_text_arg (MP mp,pointer l_delim, pointer r_delim) ;
+
+@ @c
+void mp_scan_text_arg (MP mp,pointer l_delim, pointer r_delim) {
+ integer balance; /* excess of |l_delim| over |r_delim| */
+ pointer p; /* list tail */
+ mp->warning_info=l_delim; mp->scanner_status=absorbing;
+ p=hold_head; balance=1; mp_link(hold_head)=null;
+ while (1) {
+ get_t_next;
+ if ( l_delim==0 ) {
+ @<Adjust the balance for an undelimited argument; |break| if done@>;
+ } else {
+ @<Adjust the balance for a delimited argument; |break| if done@>;
+ }
+ mp_link(p)=mp_cur_tok(mp); p=mp_link(p);
+ }
+ mp->cur_exp=mp_link(hold_head); mp->cur_type=mp_token_list;
+ mp->scanner_status=normal;
+}
+
+@ @<Adjust the balance for a delimited argument...@>=
+if ( mp->cur_cmd==right_delimiter ) {
+ if ( mp->cur_mod==l_delim ) {
+ decr(balance);
+ if ( balance==0 ) break;
+ }
+} else if ( mp->cur_cmd==left_delimiter ) {
+ if ( mp->cur_mod==r_delim ) incr(balance);
+}
+
+@ @<Adjust the balance for an undelimited...@>=
+if ( end_of_statement ) { /* |cur_cmd=semicolon|, |end_group|, or |stop| */
+ if ( balance==1 ) { break; }
+ else { if ( mp->cur_cmd==end_group ) decr(balance); }
+} else if ( mp->cur_cmd==begin_group ) {
+ incr(balance);
+}
+
+@ @<Scan undelimited argument(s)@>=
+{
+ if ( mp_info(r)<text_macro ) {
+ mp_get_x_next(mp);
+ if ( mp_info(r)!=suffix_macro ) {
+ if ( (mp->cur_cmd==equals)||(mp->cur_cmd==assignment) ) mp_get_x_next(mp);
+ }
+ }
+ switch (mp_info(r)) {
+ case primary_macro:mp_scan_primary(mp); break;
+ case secondary_macro:mp_scan_secondary(mp); break;
+ case tertiary_macro:mp_scan_tertiary(mp); break;
+ case expr_macro:mp_scan_expression(mp); break;
+ case of_macro:
+ @<Scan an expression followed by `\&{of} $\langle$primary$\rangle$'@>;
+ break;
+ case suffix_macro:
+ @<Scan a suffix with optional delimiters@>;
+ break;
+ case text_macro:mp_scan_text_arg(mp, 0,0); break;
+ } /* there are no other cases */
+ mp_back_input(mp);
+ @<Append the current expression to |arg_list|@>;
+}
+
+@ @<Scan an expression followed by `\&{of} $\langle$primary$\rangle$'@>=
+{
+ mp_scan_expression(mp); p=mp_get_avail(mp); mp_info(p)=mp_stash_cur_exp(mp);
+ if ( mp->internal[mp_tracing_macros]>0 ) {
+ mp_begin_diagnostic(mp); mp_print_arg(mp, mp_info(p),n,0);
+ mp_end_diagnostic(mp, false);
+ }
+ if ( arg_list==null ) arg_list=p; else mp_link(tail)=p;
+ tail=p;incr(n);
+ if ( mp->cur_cmd!=of_token ) {
+ mp_missing_err(mp, "of"); mp_print(mp, " for ");
+@.Missing `of'@>
+ mp_print_macro_name(mp, arg_list,macro_name);
+ help1("I've got the first argument; will look now for the other.");
+ mp_back_error(mp);
+ }
+ mp_get_x_next(mp); mp_scan_primary(mp);
+}
+
+@ @<Scan a suffix with optional delimiters@>=
+{
+ if ( mp->cur_cmd!=left_delimiter ) {
+ l_delim=null;
+ } else {
+ l_delim=mp->cur_sym; r_delim=mp->cur_mod; mp_get_x_next(mp);
+ };
+ mp_scan_suffix(mp);
+ if ( l_delim!=null ) {
+ if ((mp->cur_cmd!=right_delimiter)||(mp->cur_mod!=l_delim) ) {
+ mp_missing_err(mp, str(text(r_delim)));
+@.Missing `)'@>
+ help2("I've gotten to the end of the macro parameter list.",
+ "You might want to delete some tokens before continuing.");
+ mp_back_error(mp);
+ }
+ mp_get_x_next(mp);
+ }
+}
+
+@ Before we put a new token list on the input stack, it is wise to clean off
+all token lists that have recently been depleted. Then a user macro that ends
+with a call to itself will not require unbounded stack space.
+
+@<Feed the arguments and replacement text to the scanner@>=
+while ( token_state &&(loc==null) ) mp_end_token_list(mp); /* conserve stack space */
+if ( mp->param_ptr+n>mp->max_param_stack ) {
+ mp->max_param_stack=mp->param_ptr+n;
+ if ( mp->max_param_stack>mp->param_size )
+ mp_overflow(mp, "parameter stack size",mp->param_size);
+@:MetaPost capacity exceeded parameter stack size}{\quad parameter stack size@>
+}
+mp_begin_token_list(mp, def_ref,macro); name=macro_name; loc=r;
+if ( n>0 ) {
+ p=arg_list;
+ do {
+ mp->param_stack[mp->param_ptr]=mp_info(p); incr(mp->param_ptr); p=mp_link(p);
+ } while (p!=null);
+ mp_flush_list(mp, arg_list);
+}
+
+@ It's sometimes necessary to put a single argument onto |param_stack|.
+The |stack_argument| subroutine does this.
+
+@c
+static void mp_stack_argument (MP mp,pointer p) {
+ if ( mp->param_ptr==mp->max_param_stack ) {
+ incr(mp->max_param_stack);
+ if ( mp->max_param_stack>mp->param_size )
+ mp_overflow(mp, "parameter stack size",mp->param_size);
+@:MetaPost capacity exceeded parameter stack size}{\quad parameter stack size@>
+ }
+ mp->param_stack[mp->param_ptr]=p; incr(mp->param_ptr);
+}
+
+@* \[33] Conditional processing.
+Let's consider now the way \&{if} commands are handled.
+
+Conditions can be inside conditions, and this nesting has a stack
+that is independent of other stacks.
+Four global variables represent the top of the condition stack:
+|cond_ptr| points to pushed-down entries, if~any; |cur_if| tells whether
+we are processing \&{if} or \&{elseif}; |if_limit| specifies
+the largest code of a |fi_or_else| command that is syntactically legal;
+and |if_line| is the line number at which the current conditional began.
+
+If no conditions are currently in progress, the condition stack has the
+special state |cond_ptr=null|, |if_limit=normal|, |cur_if=0|, |if_line=0|.
+Otherwise |cond_ptr| points to a two-word node; the |type|, |name_type|, and
+|link| fields of the first word contain |if_limit|, |cur_if|, and
+|cond_ptr| at the next level, and the second word contains the
+corresponding |if_line|.
+
+@d if_node_size 2 /* number of words in stack entry for conditionals */
+@d if_line_field(A) mp->mem[(A)+1].cint
+@d if_code 1 /* code for \&{if} being evaluated */
+@d fi_code 2 /* code for \&{fi} */
+@d else_code 3 /* code for \&{else} */
+@d else_if_code 4 /* code for \&{elseif} */
+
+@<Glob...@>=
+pointer cond_ptr; /* top of the condition stack */
+integer if_limit; /* upper bound on |fi_or_else| codes */
+quarterword cur_if; /* type of conditional being worked on */
+integer if_line; /* line where that conditional began */
+
+@ @<Set init...@>=
+mp->cond_ptr=null; mp->if_limit=normal; mp->cur_if=0; mp->if_line=0;
+
+@ @<Put each...@>=
+mp_primitive(mp, "if",if_test,if_code);
+@:if_}{\&{if} primitive@>
+mp_primitive(mp, "fi",fi_or_else,fi_code); mp->eqtb[frozen_fi]=mp->eqtb[mp->cur_sym];
+@:fi_}{\&{fi} primitive@>
+mp_primitive(mp, "else",fi_or_else,else_code);
+@:else_}{\&{else} primitive@>
+mp_primitive(mp, "elseif",fi_or_else,else_if_code);
+@:else_if_}{\&{elseif} primitive@>
+
+@ @<Cases of |print_cmd_mod|...@>=
+case if_test:
+case fi_or_else:
+ switch (m) {
+ case if_code:mp_print(mp, "if"); break;
+ case fi_code:mp_print(mp, "fi"); break;
+ case else_code:mp_print(mp, "else"); break;
+ default: mp_print(mp, "elseif"); break;
+ }
+ break;
+
+@ Here is a procedure that ignores text until coming to an \&{elseif},
+\&{else}, or \&{fi} at level zero of $\&{if}\ldots\&{fi}$
+nesting. After it has acted, |cur_mod| will indicate the token that
+was found.
+
+\MP's smallest two command codes are |if_test| and |fi_or_else|; this
+makes the skipping process a bit simpler.
+
+@c
+void mp_pass_text (MP mp) {
+ integer l = 0;
+ mp->scanner_status=skipping;
+ mp->warning_info=mp_true_line(mp);
+ while (1) {
+ get_t_next;
+ if ( mp->cur_cmd<=fi_or_else ) {
+ if ( mp->cur_cmd<fi_or_else ) {
+ incr(l);
+ } else {
+ if ( l==0 ) break;
+ if ( mp->cur_mod==fi_code ) decr(l);
+ }
+ } else {
+ @<Decrease the string reference count,
+ if the current token is a string@>;
+ }
+ }
+ mp->scanner_status=normal;
+}
+
+@ @<Decrease the string reference count...@>=
+if ( mp->cur_cmd==string_token ) { delete_str_ref(mp->cur_mod); }
+
+@ When we begin to process a new \&{if}, we set |if_limit:=if_code|; then
+if \&{elseif} or \&{else} or \&{fi} occurs before the current \&{if}
+condition has been evaluated, a colon will be inserted.
+A construction like `\.{if fi}' would otherwise get \MP\ confused.
+
+@<Push the condition stack@>=
+{ p=mp_get_node(mp, if_node_size); mp_link(p)=mp->cond_ptr; mp_type(p)=mp->if_limit;
+ mp_name_type(p)=mp->cur_if; if_line_field(p)=mp->if_line;
+ mp->cond_ptr=p; mp->if_limit=if_code; mp->if_line=mp_true_line(mp);
+ mp->cur_if=if_code;
+}
+
+@ @<Pop the condition stack@>=
+{ p=mp->cond_ptr; mp->if_line=if_line_field(p);
+ mp->cur_if=mp_name_type(p); mp->if_limit=mp_type(p); mp->cond_ptr=mp_link(p);
+ mp_free_node(mp, p,if_node_size);
+}
+
+@ Here's a procedure that changes the |if_limit| code corresponding to
+a given value of |cond_ptr|.
+
+@c
+static void mp_change_if_limit (MP mp,quarterword l, pointer p) {
+ pointer q;
+ if ( p==mp->cond_ptr ) {
+ mp->if_limit=l; /* that's the easy case */
+ } else {
+ q=mp->cond_ptr;
+ while (1) {
+ if ( q==null ) mp_confusion(mp, "if");
+@:this can't happen if}{\quad if@>
+ if ( mp_link(q)==p ) {
+ mp_type(q)=l; return;
+ }
+ q=mp_link(q);
+ }
+ }
+}
+
+@ The user is supposed to put colons into the proper parts of conditional
+statements. Therefore, \MP\ has to check for their presence.
+
+@c
+static void mp_check_colon (MP mp) {
+ if ( mp->cur_cmd!=colon ) {
+ mp_missing_err(mp, ":");
+@.Missing `:'@>
+ help2("There should've been a colon after the condition.",
+ "I shall pretend that one was there.");
+ mp_back_error(mp);
+ }
+}
+
+@ A condition is started when the |get_x_next| procedure encounters
+an |if_test| command; in that case |get_x_next| calls |conditional|,
+which is a recursive procedure.
+@^recursion@>
+
+@c
+void mp_conditional (MP mp) {
+ pointer save_cond_ptr; /* |cond_ptr| corresponding to this conditional */
+ int new_if_limit; /* future value of |if_limit| */
+ pointer p; /* temporary register */
+ @<Push the condition stack@>;
+ save_cond_ptr=mp->cond_ptr;
+RESWITCH:
+ mp_get_boolean(mp); new_if_limit=else_if_code;
+ if ( mp->internal[mp_tracing_commands]>unity ) {
+ @<Display the boolean value of |cur_exp|@>;
+ }
+FOUND:
+ mp_check_colon(mp);
+ if ( mp->cur_exp==true_code ) {
+ mp_change_if_limit(mp, new_if_limit,save_cond_ptr);
+ return; /* wait for \&{elseif}, \&{else}, or \&{fi} */
+ };
+ @<Skip to \&{elseif} or \&{else} or \&{fi}, then |goto done|@>;
+DONE:
+ mp->cur_if=mp->cur_mod; mp->if_line=mp_true_line(mp);
+ if ( mp->cur_mod==fi_code ) {
+ @<Pop the condition stack@>
+ } else if ( mp->cur_mod==else_if_code ) {
+ goto RESWITCH;
+ } else {
+ mp->cur_exp=true_code; new_if_limit=fi_code; mp_get_x_next(mp);
+ goto FOUND;
+ }
+}
+
+@ In a construction like `\&{if} \&{if} \&{true}: $0=1$: \\{foo}
+\&{else}: \\{bar} \&{fi}', the first \&{else}
+that we come to after learning that the \&{if} is false is not the
+\&{else} we're looking for. Hence the following curious logic is needed.
+
+@<Skip to \&{elseif}...@>=
+while (1) {
+ mp_pass_text(mp);
+ if ( mp->cond_ptr==save_cond_ptr ) goto DONE;
+ else if ( mp->cur_mod==fi_code ) @<Pop the condition stack@>;
+}
+
+
+@ @<Display the boolean value...@>=
+{ mp_begin_diagnostic(mp);
+ if ( mp->cur_exp==true_code ) mp_print(mp, "{true}");
+ else mp_print(mp, "{false}");
+ mp_end_diagnostic(mp, false);
+}
+
+@ The processing of conditionals is complete except for the following
+code, which is actually part of |get_x_next|. It comes into play when
+\&{elseif}, \&{else}, or \&{fi} is scanned.
+
+@<Terminate the current conditional and skip to \&{fi}@>=
+if ( mp->cur_mod>mp->if_limit ) {
+ if ( mp->if_limit==if_code ) { /* condition not yet evaluated */
+ mp_missing_err(mp, ":");
+@.Missing `:'@>
+ mp_back_input(mp); mp->cur_sym=frozen_colon; mp_ins_error(mp);
+ } else {
+ print_err("Extra "); mp_print_cmd_mod(mp, fi_or_else,mp->cur_mod);
+@.Extra else@>
+@.Extra elseif@>
+@.Extra fi@>
+ help1("I'm ignoring this; it doesn't match any if.");
+ mp_error(mp);
+ }
+} else {
+ while ( mp->cur_mod!=fi_code ) mp_pass_text(mp); /* skip to \&{fi} */
+ @<Pop the condition stack@>;
+}
+
+@* \[34] Iterations.
+To bring our treatment of |get_x_next| to a close, we need to consider what
+\MP\ does when it sees \&{for}, \&{forsuffixes}, and \&{forever}.
+
+There's a global variable |loop_ptr| that keeps track of the \&{for} loops
+that are currently active. If |loop_ptr=null|, no loops are in progress;
+otherwise |mp_info(loop_ptr)| points to the iterative text of the current
+(innermost) loop, and |mp_link(loop_ptr)| points to the data for any other
+loops that enclose the current one.
+
+A loop-control node also has two other fields, called |loop_type| and
+|loop_list|, whose contents depend on the type of loop:
+
+\yskip\indent|loop_type(loop_ptr)=null| means that |loop_list(loop_ptr)|
+points to a list of one-word nodes whose |info| fields point to the
+remaining argument values of a suffix list and expression list.
+
+\yskip\indent|loop_type(loop_ptr)=mp_void| means that the current loop is
+`\&{forever}'.
+
+\yskip\indent|loop_type(loop_ptr)=progression_flag| means that
+|p=loop_list(loop_ptr)| points to a ``progression node'' and |value(p)|,
+|step_size(p)|, and |final_value(p)| contain the data for an arithmetic
+progression.
+
+\yskip\indent|loop_type(loop_ptr)=p>mp_void| means that |p| points to an edge
+header and |loop_list(loop_ptr)| points into the graphical object list for
+that edge header.
+
+\yskip\noindent In the case of a progression node, the first word is not used
+because the link field of words in the dynamic memory area cannot be arbitrary.
+
+@d loop_list_loc(A) ((A)+1) /* where the |loop_list| field resides */
+@d loop_type(A) mp_info(loop_list_loc((A))) /* the type of \&{for} loop */
+@d loop_list(A) mp_link(loop_list_loc((A))) /* the remaining list elements */
+@d loop_node_size 2 /* the number of words in a loop control node */
+@d progression_node_size 4 /* the number of words in a progression node */
+@d step_size(A) mp->mem[(A)+2].sc /* the step size in an arithmetic progression */
+@d final_value(A) mp->mem[(A)+3].sc /* the final value in an arithmetic progression */
+@d progression_flag (null+2)
+ /* |loop_type| value when |loop_list| points to a progression node */
+
+@<Glob...@>=
+pointer loop_ptr; /* top of the loop-control-node stack */
+
+@ @<Set init...@>=
+mp->loop_ptr=null;
+
+@ If the expressions that define an arithmetic progression in
+a \&{for} loop don't have known numeric values, the |bad_for|
+subroutine screams at the user.
+
+@c
+static void mp_bad_for (MP mp, const char * s) {
+ mp_disp_err(mp, null,"Improper "); /* show the bad expression above the message */
+@.Improper...replaced by 0@>
+ mp_print(mp, s); mp_print(mp, " has been replaced by 0");
+ help4("When you say `for x=a step b until c',",
+ "the initial value `a' and the step size `b'",
+ "and the final value `c' must have known numeric values.",
+ "I'm zeroing this one. Proceed, with fingers crossed.");
+ mp_put_get_flush_error(mp, 0);
+}
+
+@ Here's what \MP\ does when \&{for}, \&{forsuffixes}, or \&{forever}
+has just been scanned. (This code requires slight familiarity with
+expression-parsing routines that we have not yet discussed; but it seems
+to belong in the present part of the program, even though the original author
+didn't write it until later. The reader may wish to come back to it.)
+
+@c void mp_begin_iteration (MP mp) {
+ halfword m; /* |expr_base| (\&{for}) or |suffix_base| (\&{forsuffixes}) */
+ halfword n; /* hash address of the current symbol */
+ pointer s; /* the new loop-control node */
+ pointer p; /* substitution list for |scan_toks| */
+ pointer q; /* link manipulation register */
+ pointer pp; /* a new progression node */
+ m=mp->cur_mod; n=mp->cur_sym; s=mp_get_node(mp, loop_node_size);
+ if ( m==start_forever ){
+ loop_type(s)=mp_void; p=null; mp_get_x_next(mp);
+ } else {
+ mp_get_symbol(mp); p=mp_get_node(mp, token_node_size);
+ mp_info(p)=mp->cur_sym; value(p)=m;
+ mp_get_x_next(mp);
+ if ( mp->cur_cmd==within_token ) {
+ @<Set up a picture iteration@>;
+ } else {
+ @<Check for the |"="| or |":="| in a loop header@>;
+ @<Scan the values to be used in the loop@>;
+ }
+ }
+ @<Check for the presence of a colon@>;
+ @<Scan the loop text and put it on the loop control stack@>;
+ mp_resume_iteration(mp);
+}
+
+@ @<Check for the |"="| or |":="| in a loop header@>=
+if ( (mp->cur_cmd!=equals)&&(mp->cur_cmd!=assignment) ) {
+ mp_missing_err(mp, "=");
+@.Missing `='@>
+ help3("The next thing in this loop should have been `=' or `:='.",
+ "But don't worry; I'll pretend that an equals sign",
+ "was present, and I'll look for the values next.");
+ mp_back_error(mp);
+}
+
+@ @<Check for the presence of a colon@>=
+if ( mp->cur_cmd!=colon ) {
+ mp_missing_err(mp, ":");
+@.Missing `:'@>
+ help3("The next thing in this loop should have been a `:'.",
+ "So I'll pretend that a colon was present;",
+ "everything from here to `endfor' will be iterated.");
+ mp_back_error(mp);
+}
+
+@ We append a special |frozen_repeat_loop| token in place of the
+`\&{endfor}' at the end of the loop. This will come through \MP's scanner
+at the proper time to cause the loop to be repeated.
+
+(If the user tries some shenanigan like `\&{for} $\ldots$ \&{let} \&{endfor}',
+he will be foiled by the |get_symbol| routine, which keeps frozen
+tokens unchanged. Furthermore the |frozen_repeat_loop| is an \&{outer}
+token, so it won't be lost accidentally.)
+
+@ @<Scan the loop text...@>=
+q=mp_get_avail(mp); mp_info(q)=frozen_repeat_loop;
+mp->scanner_status=loop_defining; mp->warning_info=n;
+mp_info(s)=mp_scan_toks(mp, iteration,p,q,0); mp->scanner_status=normal;
+mp_link(s)=mp->loop_ptr; mp->loop_ptr=s
+
+@ @<Initialize table...@>=
+eq_type(frozen_repeat_loop)=repeat_loop+outer_tag;
+text(frozen_repeat_loop)=intern(" ENDFOR");
+
+@ The loop text is inserted into \MP's scanning apparatus by the
+|resume_iteration| routine.
+
+@c void mp_resume_iteration (MP mp) {
+ pointer p,q; /* link registers */
+ p=loop_type(mp->loop_ptr);
+ if ( p==progression_flag ) {
+ p=loop_list(mp->loop_ptr); /* now |p| points to a progression node */
+ mp->cur_exp=value(p);
+ if ( @<The arithmetic progression has ended@> ) {
+ mp_stop_iteration(mp);
+ return;
+ }
+ mp->cur_type=mp_known; q=mp_stash_cur_exp(mp); /* make |q| an \&{expr} argument */
+ value(p)=mp->cur_exp+step_size(p); /* set |value(p)| for the next iteration */
+ } else if ( p==null ) {
+ p=loop_list(mp->loop_ptr);
+ if ( p==null ) {
+ mp_stop_iteration(mp);
+ return;
+ }
+ loop_list(mp->loop_ptr)=mp_link(p); q=mp_info(p); free_avail(p);
+ } else if ( p==mp_void ) {
+ mp_begin_token_list(mp, mp_info(mp->loop_ptr),forever_text); return;
+ } else {
+ @<Make |q| a capsule containing the next picture component from
+ |loop_list(loop_ptr)| or |goto not_found|@>;
+ }
+ mp_begin_token_list(mp, mp_info(mp->loop_ptr),loop_text);
+ mp_stack_argument(mp, q);
+ if ( mp->internal[mp_tracing_commands]>unity ) {
+ @<Trace the start of a loop@>;
+ }
+ return;
+NOT_FOUND:
+ mp_stop_iteration(mp);
+}
+
+@ @<The arithmetic progression has ended@>=
+((step_size(p)>0)&&(mp->cur_exp>final_value(p)))||
+ ((step_size(p)<0)&&(mp->cur_exp<final_value(p)))
+
+@ @<Trace the start of a loop@>=
+{
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "{loop value=");
+@.loop value=n@>
+ if ( (q!=null)&&(mp_link(q)==mp_void) ) mp_print_exp(mp, q,1);
+ else mp_show_token_list(mp, q,null,50,0);
+ mp_print_char(mp, xord('}')); mp_end_diagnostic(mp, false);
+}
+
+@ @<Make |q| a capsule containing the next picture component from...@>=
+{ q=loop_list(mp->loop_ptr);
+ if ( q==null ) goto NOT_FOUND;
+ skip_component(q) goto NOT_FOUND;
+ mp->cur_exp=mp_copy_objects(mp, loop_list(mp->loop_ptr),q);
+ mp_init_bbox(mp, mp->cur_exp);
+ mp->cur_type=mp_picture_type;
+ loop_list(mp->loop_ptr)=q;
+ q=mp_stash_cur_exp(mp);
+}
+
+@ A level of loop control disappears when |resume_iteration| has decided
+not to resume, or when an \&{exitif} construction has removed the loop text
+from the input stack.
+
+@c void mp_stop_iteration (MP mp) {
+ pointer p,q; /* the usual */
+ p=loop_type(mp->loop_ptr);
+ if ( p==progression_flag ) {
+ mp_free_node(mp, loop_list(mp->loop_ptr),progression_node_size);
+ } else if ( p==null ){
+ q=loop_list(mp->loop_ptr);
+ while ( q!=null ) {
+ p=mp_info(q);
+ if ( p!=null ) {
+ if ( mp_link(p)==mp_void ) { /* it's an \&{expr} parameter */
+ mp_recycle_value(mp, p); mp_free_node(mp, p,value_node_size);
+ } else {
+ mp_flush_token_list(mp, p); /* it's a \&{suffix} or \&{text} parameter */
+ }
+ }
+ p=q; q=mp_link(q); free_avail(p);
+ }
+ } else if ( p>progression_flag ) {
+ delete_edge_ref(p);
+ }
+ p=mp->loop_ptr; mp->loop_ptr=mp_link(p); mp_flush_token_list(mp, mp_info(p));
+ mp_free_node(mp, p,loop_node_size);
+}
+
+@ Now that we know all about loop control, we can finish up
+the missing portion of |begin_iteration| and we'll be done.
+
+The following code is performed after the `\.=' has been scanned in
+a \&{for} construction (if |m=expr_base|) or a \&{forsuffixes} construction
+(if |m=suffix_base|).
+
+@<Scan the values to be used in the loop@>=
+loop_type(s)=null; q=loop_list_loc(s); mp_link(q)=null; /* |mp_link(q)=loop_list(s)| */
+do {
+ mp_get_x_next(mp);
+ if ( m!=expr_base ) {
+ mp_scan_suffix(mp);
+ } else {
+ if ( mp->cur_cmd>=colon ) if ( mp->cur_cmd<=comma )
+ goto CONTINUE;
+ mp_scan_expression(mp);
+ if ( mp->cur_cmd==step_token ) if ( q==loop_list_loc(s) ) {
+ @<Prepare for step-until construction and |break|@>;
+ }
+ mp->cur_exp=mp_stash_cur_exp(mp);
+ }
+ mp_link(q)=mp_get_avail(mp); q=mp_link(q);
+ mp_info(q)=mp->cur_exp; mp->cur_type=mp_vacuous;
+CONTINUE:
+ ;
+} while (mp->cur_cmd==comma)
+
+@ @<Prepare for step-until construction and |break|@>=
+{
+ if ( mp->cur_type!=mp_known ) mp_bad_for(mp, "initial value");
+ pp=mp_get_node(mp, progression_node_size); value(pp)=mp->cur_exp;
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_known ) mp_bad_for(mp, "step size");
+ step_size(pp)=mp->cur_exp;
+ if ( mp->cur_cmd!=until_token ) {
+ mp_missing_err(mp, "until");
+@.Missing `until'@>
+ help2("I assume you meant to say `until' after `step'.",
+ "So I'll look for the final value and colon next.");
+ mp_back_error(mp);
+ }
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_known ) mp_bad_for(mp, "final value");
+ final_value(pp)=mp->cur_exp; loop_list(s)=pp;
+ loop_type(s)=progression_flag;
+ break;
+}
+
+@ The last case is when we have just seen ``\&{within}'', and we need to
+parse a picture expression and prepare to iterate over it.
+
+@<Set up a picture iteration@>=
+{ mp_get_x_next(mp);
+ mp_scan_expression(mp);
+ @<Make sure the current expression is a known picture@>;
+ loop_type(s)=mp->cur_exp; mp->cur_type=mp_vacuous;
+ q=mp_link(dummy_loc(mp->cur_exp));
+ if ( q!= null )
+ if ( is_start_or_stop(q) )
+ if ( mp_skip_1component(mp, q)==null ) q=mp_link(q);
+ loop_list(s)=q;
+}
+
+@ @<Make sure the current expression is a known picture@>=
+if ( mp->cur_type!=mp_picture_type ) {
+ mp_disp_err(mp, null,"Improper iteration spec has been replaced by nullpicture");
+ help1("When you say `for x in p', p must be a known picture.");
+ mp_put_get_flush_error(mp, mp_get_node(mp, edge_header_size));
+ mp_init_edges(mp, mp->cur_exp); mp->cur_type=mp_picture_type;
+}
+
+@* \[35] File names.
+It's time now to fret about file names. Besides the fact that different
+operating systems treat files in different ways, we must cope with the
+fact that completely different naming conventions are used by different
+groups of people. The following programs show what is required for one
+particular operating system; similar routines for other systems are not
+difficult to devise.
+@^system dependencies@>
+
+\MP\ assumes that a file name has three parts: the name proper; its
+``extension''; and a ``file area'' where it is found in an external file
+system. The extension of an input file is assumed to be
+`\.{.mp}' unless otherwise specified; it is `\.{.log}' on the
+transcript file that records each run of \MP; it is `\.{.tfm}' on the font
+metric files that describe characters in any fonts created by \MP; it is
+`\.{.ps}' or `.{\it nnn}' for some number {\it nnn} on the \ps\ output files;
+and it is `\.{.mem}' on the mem files written by \.{INIMP} to initialize \MP.
+The file area can be arbitrary on input files, but files are usually
+output to the user's current area. If an input file cannot be
+found on the specified area, \MP\ will look for it on a special system
+area; this special area is intended for commonly used input files.
+
+Simple uses of \MP\ refer only to file names that have no explicit
+extension or area. For example, a person usually says `\.{input} \.{cmr10}'
+instead of `\.{input} \.{cmr10.new}'. Simple file
+names are best, because they make the \MP\ source files portable;
+whenever a file name consists entirely of letters and digits, it should be
+treated in the same way by all implementations of \MP. However, users
+need the ability to refer to other files in their environment, especially
+when responding to error messages concerning unopenable files; therefore
+we want to let them use the syntax that appears in their favorite
+operating system.
+
+@ \MP\ uses the same conventions that have proved to be satisfactory for
+\TeX\ and \MF. In order to isolate the system-dependent aspects of file names,
+@^system dependencies@>
+the system-independent parts of \MP\ are expressed in terms
+of three system-dependent
+procedures called |begin_name|, |more_name|, and |end_name|. In
+essence, if the user-specified characters of the file name are $c_1\ldots c_n$,
+the system-independent driver program does the operations
+$$|begin_name|;\,|more_name|(c_1);\,\ldots\,;\,|more_name|(c_n);
+\,|end_name|.$$
+These three procedures communicate with each other via global variables.
+Afterwards the file name will appear in the string pool as three strings
+called |cur_name|\penalty10000\hskip-.05em,
+|cur_area|, and |cur_ext|; the latter two are null (i.e.,
+|""|), unless they were explicitly specified by the user.
+
+Actually the situation is slightly more complicated, because \MP\ needs
+to know when the file name ends. The |more_name| routine is a function
+(with side effects) that returns |true| on the calls |more_name|$(c_1)$,
+\dots, |more_name|$(c_{n-1})$. The final call |more_name|$(c_n)$
+returns |false|; or, it returns |true| and $c_n$ is the last character
+on the current input line. In other words,
+|more_name| is supposed to return |true| unless it is sure that the
+file name has been completely scanned; and |end_name| is supposed to be able
+to finish the assembly of |cur_name|, |cur_area|, and |cur_ext| regardless of
+whether $|more_name|(c_n)$ returned |true| or |false|.
+
+@<Glob...@>=
+char * cur_name; /* name of file just scanned */
+char * cur_area; /* file area just scanned, or \.{""} */
+char * cur_ext; /* file extension just scanned, or \.{""} */
+
+@ It is easier to maintain reference counts if we assign initial values.
+
+@<Set init...@>=
+mp->cur_name=xstrdup("");
+mp->cur_area=xstrdup("");
+mp->cur_ext=xstrdup("");
+
+@ @<Dealloc variables@>=
+xfree(mp->cur_area);
+xfree(mp->cur_name);
+xfree(mp->cur_ext);
+
+@ The file names we shall deal with for illustrative purposes have the
+following structure: If the name contains `\.>' or `\.:', the file area
+consists of all characters up to and including the final such character;
+otherwise the file area is null. If the remaining file name contains
+`\..', the file extension consists of all such characters from the first
+remaining `\..' to the end, otherwise the file extension is null.
+@^system dependencies@>
+
+We can scan such file names easily by using two global variables that keep track
+of the occurrences of area and extension delimiters. Note that these variables
+cannot be of type |pool_pointer| because a string pool compaction could occur
+while scanning a file name.
+
+@<Glob...@>=
+integer area_delimiter;
+ /* most recent `\.>' or `\.:' relative to |str_start[str_ptr]| */
+integer ext_delimiter; /* the relevant `\..', if any */
+boolean quoted_filename; /* whether the filename is wrapped in " markers */
+
+@ Here now is the first of the system-dependent routines for file name scanning.
+@^system dependencies@>
+
+The file name length is limited to |file_name_size|. That is good, because
+in the current configuration we cannot call |mp_do_compaction| while a name
+is being scanned, |mp->area_delimiter| and |mp->ext_delimiter| are direct
+offsets into |mp->str_pool|. I am not in a great hurry to fix this, because
+calling |str_room()| just once is more efficient anyway. TODO.
+
+@<Declarations@>=
+static void mp_begin_name (MP mp);
+static boolean mp_more_name (MP mp, ASCII_code c);
+static void mp_end_name (MP mp);
+
+@ @c
+void mp_begin_name (MP mp) {
+ xfree(mp->cur_name);
+ xfree(mp->cur_area);
+ xfree(mp->cur_ext);
+ mp->area_delimiter=-1;
+ mp->ext_delimiter=-1;
+ mp->quoted_filename=false;
+ str_room(file_name_size);
+}
+
+@ And here's the second.
+@^system dependencies@>
+
+@d IS_DIR_SEP(c) (c=='/' || c=='\\')
+
+@c
+boolean mp_more_name (MP mp, ASCII_code c) {
+ if (c=='"') {
+ mp->quoted_filename= ! mp->quoted_filename;
+ } else if ((c==' '|| c=='\t') && (mp->quoted_filename==false)) {
+ return false;
+ } else {
+ if (IS_DIR_SEP (c)) {
+ mp->area_delimiter=mp->pool_ptr;
+ mp->ext_delimiter=-1;
+ } else if ( c=='.' ) {
+ mp->ext_delimiter=mp->pool_ptr;
+ }
+ append_char(c); /* contribute |c| to the current string */
+ }
+ return true;
+}
+
+@ The third.
+@^system dependencies@>
+
+@d copy_pool_segment(A,B,C) {
+ A = xmalloc(C+1,sizeof(char));
+ strncpy(A,(char *)(mp->str_pool+B),C);
+ A[C] = 0;}
+
+@c
+void mp_end_name (MP mp) {
+ pool_pointer s; /* length of area, name, and extension */
+ unsigned int len;
+ /* "my/w.mp" */
+ s = mp->str_start[mp->str_ptr];
+ if ( mp->area_delimiter<0 ) {
+ mp->cur_area=xstrdup("");
+ } else {
+ len = (unsigned)(mp->area_delimiter-s+1);
+ copy_pool_segment(mp->cur_area,s,len);
+ s += len;
+ }
+ if ( mp->ext_delimiter<0 ) {
+ mp->cur_ext=xstrdup("");
+ len = (unsigned)(mp->pool_ptr-s);
+ } else {
+ copy_pool_segment(mp->cur_ext,mp->ext_delimiter,(size_t)(mp->pool_ptr-mp->ext_delimiter));
+ len = (unsigned)(mp->ext_delimiter-s);
+ }
+ copy_pool_segment(mp->cur_name,s,len);
+ mp->pool_ptr=s; /* don't need this partial string */
+}
+
+@ Conversely, here is a routine that takes three strings and prints a file
+name that might have produced them. (The routine is system dependent, because
+some operating systems put the file area last instead of first.)
+@^system dependencies@>
+
+@<Basic printing...@>=
+static void mp_print_file_name (MP mp, char * n, char * a, char * e) {
+ boolean must_quote = false;
+ if (((a != NULL) && (strchr(a,' ') != NULL)) ||
+ ((n != NULL) && (strchr(n,' ') != NULL)) ||
+ ((e != NULL) && (strchr(e,' ') != NULL)))
+ must_quote = true;
+ if (must_quote) mp_print_char(mp, (ASCII_code)'"');
+ mp_print(mp, a); mp_print(mp, n); mp_print(mp, e);
+ if (must_quote) mp_print_char(mp, (ASCII_code)'"');
+}
+
+@ Another system-dependent routine is needed to convert three internal
+\MP\ strings
+to the |name_of_file| value that is used to open files. The present code
+allows both lowercase and uppercase letters in the file name.
+@^system dependencies@>
+
+@d append_to_name(A) { c=xord((ASCII_code)(A));
+ if ( k<file_name_size ) {
+ mp->name_of_file[k]=(char)xchr(c);
+ incr(k);
+ }
+}
+
+@ @c
+void mp_pack_file_name (MP mp, const char *n, const char *a, const char *e) {
+ integer k; /* number of positions filled in |name_of_file| */
+ ASCII_code c; /* character being packed */
+ const char *j; /* a character index */
+ k=0;
+ assert(n!=NULL);
+ if (a!=NULL) {
+ for (j=a;*j!='\0';j++) { append_to_name(*j); }
+ }
+ for (j=n;*j!='\0';j++) { append_to_name(*j); }
+ if (e!=NULL) {
+ for (j=e;*j!='\0';j++) { append_to_name(*j); }
+ }
+ mp->name_of_file[k]=0;
+ mp->name_length=k;
+}
+
+@ @<Internal library declarations@>=
+void mp_pack_file_name (MP mp, const char *n, const char *a, const char *e) ;
+
+@ @<Option variables@>=
+char *mem_name; /* for commandline */
+
+@ @<Find constant sizes@>=
+mp->mem_name = xstrdup(opt->mem_name);
+if (mp->mem_name) {
+ size_t l = strlen(mp->mem_name);
+ if (l>4) {
+ char *test = strstr(mp->mem_name,".mem");
+ if (test == mp->mem_name+l-4) {
+ *test = 0;
+ }
+ }
+}
+
+
+@ @<Dealloc variables@>=
+xfree(mp->mem_name);
+
+@ This part of the program becomes active when a ``virgin'' \MP\ is
+trying to get going, just after the preliminary initialization, or
+when the user is substituting another mem file by typing `\.\&' after
+the initial `\.{**}' prompt. The buffer contains the first line of
+input in |buffer[loc..(last-1)]|, where |loc<last| and |buffer[loc]<>""|.
+
+@<Declarations@>=
+static boolean mp_open_mem_name (MP mp) ;
+static boolean mp_open_mem_file (MP mp) ;
+
+@ @c
+boolean mp_open_mem_name (MP mp) {
+ if (mp->mem_name!=NULL) {
+ size_t l = strlen(mp->mem_name);
+ char *s = xstrdup (mp->mem_name);
+ if (l>4) {
+ char *test = strstr(s,".mem");
+ if (test == NULL || test != s+l-4) {
+ s = xrealloc (s, l+5, 1);
+ strcat (s, ".mem");
+ }
+ } else {
+ s = xrealloc (s, l+5, 1);
+ strcat (s, ".mem");
+ }
+ mp->mem_file = (mp->open_file)(mp,s, "r", mp_filetype_memfile);
+ xfree(s);
+ if ( mp->mem_file ) return true;
+ }
+ return false;
+}
+boolean mp_open_mem_file (MP mp) {
+ if (mp->mem_file != NULL)
+ return true;
+ if (mp_open_mem_name(mp))
+ return true;
+ if (mp_xstrcmp(mp->mem_name, "plain")) {
+ wake_up_terminal;
+ wterm_ln("Sorry, I can\'t find that mem file; will try PLAIN.");
+@.Sorry, I can't find...@>
+ update_terminal;
+ /* now pull out all the stops: try for the system \.{plain} file */
+ xfree(mp->mem_name);
+ mp->mem_name = xstrdup("plain");
+ if (mp_open_mem_name(mp))
+ return true;
+ }
+ wake_up_terminal;
+ wterm_ln("I can\'t find the PLAIN mem file!\n");
+@.I can't find PLAIN...@>
+@.plain@>
+ return false;
+}
+
+@ Operating systems often make it possible to determine the exact name (and
+possible version number) of a file that has been opened. The following routine,
+which simply makes a \MP\ string from the value of |name_of_file|, should
+ideally be changed to deduce the full name of file~|f|, which is the file
+most recently opened, if it is possible to do this.
+@^system dependencies@>
+
+@<Declarations@>=
+#define mp_a_make_name_string(A,B) mp_make_name_string(A)
+#define mp_b_make_name_string(A,B) mp_make_name_string(A)
+#define mp_w_make_name_string(A,B) mp_make_name_string(A)
+
+@ @c
+static str_number mp_make_name_string (MP mp) {
+ int k; /* index into |name_of_file| */
+ str_room(mp->name_length);
+ for (k=0;k<mp->name_length;k++) {
+ append_char(xord((ASCII_code)mp->name_of_file[k]));
+ }
+ return mp_make_string(mp);
+}
+
+@ Now let's consider the ``driver''
+routines by which \MP\ deals with file names
+in a system-independent manner. First comes a procedure that looks for a
+file name in the input by taking the information from the input buffer.
+(We can't use |get_next|, because the conversion to tokens would
+destroy necessary information.)
+
+This procedure doesn't allow semicolons or percent signs to be part of
+file names, because of other conventions of \MP.
+{\sl The {\logos METAFONT\/}book} doesn't
+use semicolons or percents immediately after file names, but some users
+no doubt will find it natural to do so; therefore system-dependent
+changes to allow such characters in file names should probably
+be made with reluctance, and only when an entire file name that
+includes special characters is ``quoted'' somehow.
+@^system dependencies@>
+
+@c
+static void mp_scan_file_name (MP mp) {
+ mp_begin_name(mp);
+ while ( mp->buffer[loc]==' ' ) incr(loc);
+ while (1) {
+ if ( (mp->buffer[loc]==';')||(mp->buffer[loc]=='%') ) break;
+ if ( ! mp_more_name(mp, mp->buffer[loc]) ) break;
+ incr(loc);
+ }
+ mp_end_name(mp);
+}
+
+@ Here is another version that takes its input from a string.
+
+@<Declare subroutines for parsing file names@>=
+void mp_str_scan_file (MP mp, str_number s) ;
+
+@ @c
+void mp_str_scan_file (MP mp, str_number s) {
+ pool_pointer p,q; /* current position and stopping point */
+ mp_begin_name(mp);
+ p=mp->str_start[s]; q=str_stop(s);
+ while ( p<q ){
+ if ( ! mp_more_name(mp, mp->str_pool[p]) ) break;
+ incr(p);
+ }
+ mp_end_name(mp);
+}
+
+@ And one that reads from a |char*|.
+
+@<Declare subroutines for parsing file names@>=
+extern void mp_ptr_scan_file (MP mp, char *s);
+
+@ @c
+void mp_ptr_scan_file (MP mp, char *s) {
+ char *p, *q; /* current position and stopping point */
+ mp_begin_name(mp);
+ p=s; q=p+strlen(s);
+ while ( p<q ){
+ if ( ! mp_more_name(mp, xord((ASCII_code)(*p)))) break;
+ p++;
+ }
+ mp_end_name(mp);
+}
+
+
+@ The global variable |job_name| contains the file name that was first
+\&{input} by the user. This name is extended by `\.{.log}' and `\.{ps}' and
+`\.{.mem}' and `\.{.tfm}' in order to make the names of \MP's output files.
+
+@<Glob...@>=
+boolean log_opened; /* has the transcript file been opened? */
+char *log_name; /* full name of the log file */
+
+@ @<Option variables@>=
+char *job_name; /* principal file name */
+
+@ Initially |job_name=NULL|; it becomes nonzero as soon as the true name is known.
+We have |job_name=NULL| if and only if the `\.{log}' file has not been opened,
+except of course for a short time just after |job_name| has become nonzero.
+
+@<Allocate or ...@>=
+mp->job_name=mp_xstrdup(mp, opt->job_name);
+if (opt->noninteractive && opt->ini_version) {
+ if (mp->job_name == NULL)
+ mp->job_name=mp_xstrdup(mp,mp->mem_name);
+ if (mp->job_name != NULL) {
+ size_t l = strlen(mp->job_name);
+ if (l>4) {
+ char *test = strstr(mp->job_name,".mem");
+ if (test == mp->job_name+l-4)
+ *test = 0;
+ }
+ }
+}
+mp->log_opened=false;
+
+@ @<Dealloc variables@>=
+xfree(mp->job_name);
+
+@ Here is a routine that manufactures the output file names, assuming that
+|job_name<>0|. It ignores and changes the current settings of |cur_area|
+and |cur_ext|.
+
+@d pack_cur_name mp_pack_file_name(mp, mp->cur_name,mp->cur_area,mp->cur_ext)
+
+@<Internal library ...@>=
+void mp_pack_job_name (MP mp, const char *s) ;
+
+@ @c
+void mp_pack_job_name (MP mp, const char *s) { /* |s = ".log"|, |".mem"|, |".ps"|, or .\\{nnn} */
+ xfree(mp->cur_name); mp->cur_name=xstrdup(mp->job_name);
+ xfree(mp->cur_area); mp->cur_area=xstrdup("");
+ xfree(mp->cur_ext); mp->cur_ext=xstrdup(s);
+ pack_cur_name;
+}
+
+@ If some trouble arises when \MP\ tries to open a file, the following
+routine calls upon the user to supply another file name. Parameter~|s|
+is used in the error message to identify the type of file; parameter~|e|
+is the default extension if none is given. Upon exit from the routine,
+variables |cur_name|, |cur_area|, |cur_ext|, and |name_of_file| are
+ready for another attempt at file opening.
+
+@<Internal library ...@>=
+void mp_prompt_file_name (MP mp, const char * s, const char * e) ;
+
+@ @c void mp_prompt_file_name (MP mp, const char * s, const char * e) {
+ size_t k; /* index into |buffer| */
+ char * saved_cur_name;
+ if ( mp->interaction==mp_scroll_mode )
+ wake_up_terminal;
+ if (strcmp(s,"input file name")==0) {
+ print_err("I can\'t find file `");
+@.I can't find file x@>
+ } else {
+ print_err("I can\'t write on file `");
+@.I can't write on file x@>
+ }
+ mp_print_file_name(mp, mp->cur_name,mp->cur_area,mp->cur_ext);
+ mp_print(mp, "'.");
+ if (strcmp(e,"")==0)
+ mp_show_context(mp);
+ mp_print_nl(mp, "Please type another "); mp_print(mp, s);
+@.Please type...@>
+ if (mp->noninteractive || mp->interaction<mp_scroll_mode )
+ mp_fatal_error(mp, "*** (job aborted, file error in nonstop mode)");
+@.job aborted, file error...@>
+ saved_cur_name = xstrdup(mp->cur_name);
+ clear_terminal; prompt_input(": "); @<Scan file name in the buffer@>;
+ if (strcmp(mp->cur_ext,"")==0)
+ mp->cur_ext=xstrdup(e);
+ if (strlen(mp->cur_name)==0) {
+ mp->cur_name=saved_cur_name;
+ } else {
+ xfree(saved_cur_name);
+ }
+ pack_cur_name;
+}
+
+@ @<Scan file name in the buffer@>=
+{
+ mp_begin_name(mp); k=mp->first;
+ while ( (mp->buffer[k]==' ')&&(k<mp->last) ) incr(k);
+ while (1) {
+ if ( k==mp->last ) break;
+ if ( ! mp_more_name(mp, mp->buffer[k]) ) break;
+ incr(k);
+ }
+ mp_end_name(mp);
+}
+
+@ The |open_log_file| routine is used to open the transcript file and to help
+it catch up to what has previously been printed on the terminal.
+
+@c void mp_open_log_file (MP mp) {
+ unsigned old_setting; /* previous |selector| setting */
+ int k; /* index into |months| and |buffer| */
+ int l; /* end of first input line */
+ integer m; /* the current month */
+ const char *months="JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC";
+ /* abbreviations of month names */
+ old_setting=mp->selector;
+ if ( mp->job_name==NULL ) {
+ mp->job_name=xstrdup("mpout");
+ }
+ mp_pack_job_name(mp,".log");
+ while ( ! mp_a_open_out(mp, &mp->log_file, mp_filetype_log) ) {
+ @<Try to get a different log file name@>;
+ }
+ mp->log_name=xstrdup(mp->name_of_file);
+ mp->selector=log_only; mp->log_opened=true;
+ @<Print the banner line, including the date and time@>;
+ mp->input_stack[mp->input_ptr]=mp->cur_input;
+ /* make sure bottom level is in memory */
+ if (!mp->noninteractive) {
+ mp_print_nl(mp, "**");
+@.**@>
+ l=mp->input_stack[0].limit_field-1; /* last position of first line */
+ for (k=0;k<=l;k++) mp_print_str(mp, mp->buffer[k]);
+ mp_print_ln(mp); /* now the transcript file contains the first line of input */
+ }
+ mp->selector=old_setting+2; /* |log_only| or |term_and_log| */
+}
+
+@ @<Dealloc variables@>=
+xfree(mp->log_name);
+
+@ Sometimes |open_log_file| is called at awkward moments when \MP\ is
+unable to print error messages or even to |show_context|.
+The |prompt_file_name| routine can result in a |fatal_error|, but the |error|
+routine will not be invoked because |log_opened| will be false.
+
+The normal idea of |mp_batch_mode| is that nothing at all should be written
+on the terminal. However, in the unusual case that
+no log file could be opened, we make an exception and allow
+an explanatory message to be seen.
+
+Incidentally, the program always refers to the log file as a `\.{transcript
+file}', because some systems cannot use the extension `\.{.log}' for
+this file.
+
+@<Try to get a different log file name@>=
+{
+ mp->selector=term_only;
+ mp_prompt_file_name(mp, "transcript file name",".log");
+}
+
+@ @<Print the banner...@>=
+{
+ wlog(mp->banner);
+ mp_print(mp, mp->mem_ident); mp_print(mp, " ");
+ mp_print_int(mp, mp_round_unscaled(mp, mp->internal[mp_day]));
+ mp_print_char(mp, xord(' '));
+ m=mp_round_unscaled(mp, mp->internal[mp_month]);
+ for (k=3*m-3;k<3*m;k++) { wlog_chr((unsigned char)months[k]); }
+ mp_print_char(mp, xord(' '));
+ mp_print_int(mp, mp_round_unscaled(mp, mp->internal[mp_year]));
+ mp_print_char(mp, xord(' '));
+ m=mp_round_unscaled(mp, mp->internal[mp_time]);
+ mp_print_dd(mp, m / 60); mp_print_char(mp, xord(':')); mp_print_dd(mp, m % 60);
+}
+
+@ The |try_extension| function tries to open an input file determined by
+|cur_name|, |cur_area|, and the argument |ext|. It returns |false| if it
+can't find the file in |cur_area| or the appropriate system area.
+
+@c
+static boolean mp_try_extension (MP mp, const char *ext) {
+ mp_pack_file_name(mp, mp->cur_name,mp->cur_area, ext);
+ in_name=xstrdup(mp->cur_name);
+ in_area=xstrdup(mp->cur_area);
+ if ( mp_a_open_in(mp, &cur_file, mp_filetype_program) ) {
+ return true;
+ } else {
+ mp_pack_file_name(mp, mp->cur_name,NULL,ext);
+ return mp_a_open_in(mp, &cur_file, mp_filetype_program);
+ }
+}
+
+@ Let's turn now to the procedure that is used to initiate file reading
+when an `\.{input}' command is being processed.
+
+@c void mp_start_input (MP mp) { /* \MP\ will \.{input} something */
+ char *fname = NULL;
+ @<Put the desired file name in |(cur_name,cur_ext,cur_area)|@>;
+ while (1) {
+ mp_begin_file_reading(mp); /* set up |cur_file| and new level of input */
+ if ( strlen(mp->cur_ext)==0 ) {
+ if ( mp_try_extension(mp, ".mp") ) break;
+ else if ( mp_try_extension(mp, "") ) break;
+ else if ( mp_try_extension(mp, ".mf") ) break;
+ /* |else do_nothing; | */
+ } else if ( mp_try_extension(mp, mp->cur_ext) ) {
+ break;
+ }
+ mp_end_file_reading(mp); /* remove the level that didn't work */
+ mp_prompt_file_name(mp, "input file name","");
+ }
+ name=mp_a_make_name_string(mp, cur_file);
+ fname = xstrdup(mp->name_of_file);
+ if ( mp->job_name==NULL ) {
+ mp->job_name=xstrdup(mp->cur_name);
+ mp_open_log_file(mp);
+ } /* |open_log_file| doesn't |show_context|, so |limit|
+ and |loc| needn't be set to meaningful values yet */
+ if ( ((int)mp->term_offset+(int)strlen(fname)) > (mp->max_print_line-2)) mp_print_ln(mp);
+ else if ( (mp->term_offset>0)||(mp->file_offset>0) ) mp_print_char(mp, xord(' '));
+ mp_print_char(mp, xord('(')); incr(mp->open_parens); mp_print(mp, fname);
+ xfree(fname);
+ update_terminal;
+ @<Flush |name| and replace it with |cur_name| if it won't be needed@>;
+ @<Read the first line of the new file@>;
+}
+
+@ This code should be omitted if |a_make_name_string| returns something other
+than just a copy of its argument and the full file name is needed for opening
+\.{MPX} files or implementing the switch-to-editor option.
+@^system dependencies@>
+
+@<Flush |name| and replace it with |cur_name| if it won't be needed@>=
+mp_flush_string(mp, name); name=rts(mp->cur_name); xfree(mp->cur_name)
+
+@ If the file is empty, it is considered to contain a single blank line,
+so there is no need to test the return value.
+
+@<Read the first line...@>=
+{
+ line=1;
+ (void)mp_input_ln(mp, cur_file );
+ mp_firm_up_the_line(mp);
+ mp->buffer[limit]=xord('%'); mp->first=(size_t)(limit+1); loc=start;
+}
+
+@ @<Put the desired file name in |(cur_name,cur_ext,cur_area)|@>=
+while ( token_state &&(loc==null) ) mp_end_token_list(mp);
+if ( token_state ) {
+ print_err("File names can't appear within macros");
+@.File names can't...@>
+ help3("Sorry...I've converted what follows to tokens,",
+ "possibly garbaging the name you gave.",
+ "Please delete the tokens and insert the name again.");
+ mp_error(mp);
+}
+if ( file_state ) {
+ mp_scan_file_name(mp);
+} else {
+ xfree(mp->cur_name); mp->cur_name=xstrdup("");
+ xfree(mp->cur_ext); mp->cur_ext =xstrdup("");
+ xfree(mp->cur_area); mp->cur_area=xstrdup("");
+}
+
+@ The following simple routine starts reading the \.{MPX} file associated
+with the current input file.
+
+@c void mp_start_mpx_input (MP mp) {
+ char *origname = NULL; /* a copy of nameoffile */
+ mp_pack_file_name(mp, in_name, in_area, ".mpx");
+ @<Try to make sure |name_of_file| refers to a valid \.{MPX} file and
+ |goto not_found| if there is a problem@>;
+ mp_begin_file_reading(mp);
+ if ( ! mp_a_open_in(mp, &cur_file, mp_filetype_program) ) {
+ mp_end_file_reading(mp);
+ goto NOT_FOUND;
+ }
+ name=mp_a_make_name_string(mp, cur_file);
+ mp->mpx_name[iindex]=name; add_str_ref(name);
+ @<Read the first line of the new file@>;
+ xfree(origname);
+ return;
+NOT_FOUND:
+ @<Explain that the \.{MPX} file can't be read and |succumb|@>;
+ xfree(origname);
+}
+
+@ This should ideally be changed to do whatever is necessary to create the
+\.{MPX} file given by |name_of_file| if it does not exist or if it is out
+of date. This requires invoking \.{MPtoTeX} on the |origname| and passing
+the results through \TeX\ and \.{DVItoMP}. (It is possible to use a
+completely different typesetting program if suitable postprocessor is
+available to perform the function of \.{DVItoMP}.)
+@^system dependencies@>
+
+@ @<Exported types@>=
+typedef int (*mp_makempx_cmd)(MP mp, char *origname, char *mtxname);
+
+@ @<Option variables@>=
+mp_makempx_cmd run_make_mpx;
+
+@ @<Allocate or initialize ...@>=
+set_callback_option(run_make_mpx);
+
+@ @<Declarations@>=
+static int mp_run_make_mpx (MP mp, char *origname, char *mtxname);
+
+@ The default does nothing.
+@c
+int mp_run_make_mpx (MP mp, char *origname, char *mtxname) {
+ (void)mp;
+ (void)origname;
+ (void)mtxname;
+ return false;
+}
+
+@ @<Try to make sure |name_of_file| refers to a valid \.{MPX} file and
+ |goto not_found| if there is a problem@>=
+origname = mp_xstrdup(mp,mp->name_of_file);
+*(origname+strlen(origname)-1)=0; /* drop the x */
+if (!(mp->run_make_mpx)(mp, origname, mp->name_of_file))
+ goto NOT_FOUND
+
+@ @<Explain that the \.{MPX} file can't be read and |succumb|@>=
+if ( mp->interaction==mp_error_stop_mode ) wake_up_terminal;
+mp_print_nl(mp, ">> ");
+mp_print(mp, origname);
+mp_print_nl(mp, ">> ");
+mp_print(mp, mp->name_of_file);
+mp_print_nl(mp, "! Unable to make mpx file");
+help4("The two files given above are one of your source files",
+ "and an auxiliary file I need to read to find out what your",
+ "btex..etex blocks mean. If you don't know why I had trouble,",
+ "try running it manually through MPtoTeX, TeX, and DVItoMP");
+succumb;
+
+@ The last file-opening commands are for files accessed via the \&{readfrom}
+@:read_from_}{\&{readfrom} primitive@>
+operator and the \&{write} command. Such files are stored in separate arrays.
+@:write_}{\&{write} primitive@>
+
+@<Types in the outer block@>=
+typedef unsigned int readf_index; /* |0..max_read_files| */
+typedef unsigned int write_index; /* |0..max_write_files| */
+
+@ @<Glob...@>=
+readf_index max_read_files; /* maximum number of simultaneously open \&{readfrom} files */
+void ** rd_file; /* \&{readfrom} files */
+char ** rd_fname; /* corresponding file name or 0 if file not open */
+readf_index read_files; /* number of valid entries in the above arrays */
+write_index max_write_files; /* maximum number of simultaneously open \&{write} */
+void ** wr_file; /* \&{write} files */
+char ** wr_fname; /* corresponding file name or 0 if file not open */
+write_index write_files; /* number of valid entries in the above arrays */
+
+@ @<Allocate or initialize ...@>=
+mp->max_read_files=8;
+mp->rd_file = xmalloc((mp->max_read_files+1),sizeof(void *));
+mp->rd_fname = xmalloc((mp->max_read_files+1),sizeof(char *));
+memset(mp->rd_fname, 0, sizeof(char *)*(mp->max_read_files+1));
+mp->max_write_files=8;
+mp->wr_file = xmalloc((mp->max_write_files+1),sizeof(void *));
+mp->wr_fname = xmalloc((mp->max_write_files+1),sizeof(char *));
+memset(mp->wr_fname, 0, sizeof(char *)*(mp->max_write_files+1));
+
+
+@ This routine starts reading the file named by string~|s| without setting
+|loc|, |limit|, or |name|. It returns |false| if the file is empty or cannot
+be opened. Otherwise it updates |rd_file[n]| and |rd_fname[n]|.
+
+@c
+static boolean mp_start_read_input (MP mp,char *s, readf_index n) {
+ mp_ptr_scan_file(mp, s);
+ pack_cur_name;
+ mp_begin_file_reading(mp);
+ if ( ! mp_a_open_in(mp, &mp->rd_file[n], (int)(mp_filetype_text+n)) )
+ goto NOT_FOUND;
+ if ( ! mp_input_ln(mp, mp->rd_file[n] ) ) {
+ (mp->close_file)(mp,mp->rd_file[n]);
+ goto NOT_FOUND;
+ }
+ mp->rd_fname[n]=xstrdup(s);
+ return true;
+NOT_FOUND:
+ mp_end_file_reading(mp);
+ return false;
+}
+
+@ Open |wr_file[n]| using file name~|s| and update |wr_fname[n]|.
+
+@<Declarations@>=
+static void mp_open_write_file (MP mp, char *s, readf_index n) ;
+
+@ @c void mp_open_write_file (MP mp,char *s, readf_index n) {
+ mp_ptr_scan_file(mp, s);
+ pack_cur_name;
+ while ( ! mp_a_open_out(mp, &mp->wr_file[n], (int)(mp_filetype_text+n)) )
+ mp_prompt_file_name(mp, "file name for write output","");
+ mp->wr_fname[n]=xstrdup(s);
+}
+
+
+@* \[36] Introduction to the parsing routines.
+We come now to the central nervous system that sparks many of \MP's activities.
+By evaluating expressions, from their primary constituents to ever larger
+subexpressions, \MP\ builds the structures that ultimately define complete
+pictures or fonts of type.
+
+Four mutually recursive subroutines are involved in this process: We call them
+$$\hbox{|scan_primary|, |scan_secondary|, |scan_tertiary|,
+and |scan_expression|.}$$
+@^recursion@>
+Each of them is parameterless and begins with the first token to be scanned
+already represented in |cur_cmd|, |cur_mod|, and |cur_sym|. After execution,
+the value of the primary or secondary or tertiary or expression that was
+found will appear in the global variables |cur_type| and |cur_exp|. The
+token following the expression will be represented in |cur_cmd|, |cur_mod|,
+and |cur_sym|.
+
+Technically speaking, the parsing algorithms are ``LL(1),'' more or less;
+backup mechanisms have been added in order to provide reasonable error
+recovery.
+
+@<Glob...@>=
+quarterword cur_type; /* the type of the expression just found */
+integer cur_exp; /* the value of the expression just found */
+
+@ @<Set init...@>=
+mp->cur_exp=0;
+
+@ Many different kinds of expressions are possible, so it is wise to have
+precise descriptions of what |cur_type| and |cur_exp| mean in all cases:
+
+\smallskip\hang
+|cur_type=mp_vacuous| means that this expression didn't turn out to have a
+value at all, because it arose from a \&{begingroup}$\,\ldots\,$\&{endgroup}
+construction in which there was no expression before the \&{endgroup}.
+In this case |cur_exp| has some irrelevant value.
+
+\smallskip\hang
+|cur_type=mp_boolean_type| means that |cur_exp| is either |true_code|
+or |false_code|.
+
+\smallskip\hang
+|cur_type=mp_unknown_boolean| means that |cur_exp| points to a capsule
+node that is in
+a ring of equivalent booleans whose value has not yet been defined.
+
+\smallskip\hang
+|cur_type=mp_string_type| means that |cur_exp| is a string number (i.e., an
+integer in the range |0<=cur_exp<str_ptr|). That string's reference count
+includes this particular reference.
+
+\smallskip\hang
+|cur_type=mp_unknown_string| means that |cur_exp| points to a capsule
+node that is in
+a ring of equivalent strings whose value has not yet been defined.
+
+\smallskip\hang
+|cur_type=mp_pen_type| means that |cur_exp| points to a node in a pen. Nobody
+else points to any of the nodes in this pen. The pen may be polygonal or
+elliptical.
+
+\smallskip\hang
+|cur_type=mp_unknown_pen| means that |cur_exp| points to a capsule
+node that is in
+a ring of equivalent pens whose value has not yet been defined.
+
+\smallskip\hang
+|cur_type=mp_path_type| means that |cur_exp| points to a the first node of
+a path; nobody else points to this particular path. The control points of
+the path will have been chosen.
+
+\smallskip\hang
+|cur_type=mp_unknown_path| means that |cur_exp| points to a capsule
+node that is in
+a ring of equivalent paths whose value has not yet been defined.
+
+\smallskip\hang
+|cur_type=mp_picture_type| means that |cur_exp| points to an edge header node.
+There may be other pointers to this particular set of edges. The header node
+contains a reference count that includes this particular reference.
+
+\smallskip\hang
+|cur_type=mp_unknown_picture| means that |cur_exp| points to a capsule
+node that is in
+a ring of equivalent pictures whose value has not yet been defined.
+
+\smallskip\hang
+|cur_type=mp_transform_type| means that |cur_exp| points to a |mp_transform_type|
+capsule node. The |value| part of this capsule
+points to a transform node that contains six numeric values,
+each of which is |independent|, |dependent|, |mp_proto_dependent|, or |known|.
+
+\smallskip\hang
+|cur_type=mp_color_type| means that |cur_exp| points to a |color_type|
+capsule node. The |value| part of this capsule
+points to a color node that contains three numeric values,
+each of which is |independent|, |dependent|, |mp_proto_dependent|, or |known|.
+
+\smallskip\hang
+|cur_type=mp_cmykcolor_type| means that |cur_exp| points to a |mp_cmykcolor_type|
+capsule node. The |value| part of this capsule
+points to a color node that contains four numeric values,
+each of which is |independent|, |dependent|, |mp_proto_dependent|, or |known|.
+
+\smallskip\hang
+|cur_type=mp_pair_type| means that |cur_exp| points to a capsule
+node whose type is |mp_pair_type|. The |value| part of this capsule
+points to a pair node that contains two numeric values,
+each of which is |independent|, |dependent|, |mp_proto_dependent|, or |known|.
+
+\smallskip\hang
+|cur_type=mp_known| means that |cur_exp| is a |scaled| value.
+
+\smallskip\hang
+|cur_type=mp_dependent| means that |cur_exp| points to a capsule node whose type
+is |dependent|. The |dep_list| field in this capsule points to the associated
+dependency list.
+
+\smallskip\hang
+|cur_type=mp_proto_dependent| means that |cur_exp| points to a |mp_proto_dependent|
+capsule node. The |dep_list| field in this capsule
+points to the associated dependency list.
+
+\smallskip\hang
+|cur_type=independent| means that |cur_exp| points to a capsule node
+whose type is |independent|. This somewhat unusual case can arise, for
+example, in the expression
+`$x+\&{begingroup}\penalty0\,\&{string}\,x; 0\,\&{endgroup}$'.
+
+\smallskip\hang
+|cur_type=mp_token_list| means that |cur_exp| points to a linked list of
+tokens.
+
+\smallskip\noindent
+The possible settings of |cur_type| have been listed here in increasing
+numerical order. Notice that |cur_type| will never be |mp_numeric_type| or
+|suffixed_macro| or |mp_unsuffixed_macro|, although variables of those types
+are allowed. Conversely, \MP\ has no variables of type |mp_vacuous| or
+|token_list|.
+
+@ Capsules are two-word nodes that have a similar meaning
+to |cur_type| and |cur_exp|. Such nodes have |name_type=capsule|,
+and their |type| field is one of the possibilities for |cur_type| listed above.
+Also |link<=void| in capsules that aren't part of a token list.
+
+The |value| field of a capsule is, in most cases, the value that
+corresponds to its |type|, as |cur_exp| corresponds to |cur_type|.
+However, when |cur_exp| would point to a capsule,
+no extra layer of indirection is present; the |value|
+field is what would have been called |value(cur_exp)| if it had not been
+encapsulated. Furthermore, if the type is |dependent| or
+|mp_proto_dependent|, the |value| field of a capsule is replaced by
+|dep_list| and |prev_dep| fields, since dependency lists in capsules are
+always part of the general |dep_list| structure.
+
+The |get_x_next| routine is careful not to change the values of |cur_type|
+and |cur_exp| when it gets an expanded token. However, |get_x_next| might
+call a macro, which might parse an expression, which might execute lots of
+commands in a group; hence it's possible that |cur_type| might change
+from, say, |mp_unknown_boolean| to |mp_boolean_type|, or from |dependent| to
+|known| or |independent|, during the time |get_x_next| is called. The
+programs below are careful to stash sensitive intermediate results in
+capsules, so that \MP's generality doesn't cause trouble.
+
+Here's a procedure that illustrates these conventions. It takes
+the contents of $(|cur_type|\kern-.3pt,|cur_exp|\kern-.3pt)$
+and stashes them away in a
+capsule. It is not used when |cur_type=mp_token_list|.
+After the operation, |cur_type=mp_vacuous|; hence there is no need to
+copy path lists or to update reference counts, etc.
+
+The special link |mp_void| is put on the capsule returned by
+|stash_cur_exp|, because this procedure is used to store macro parameters
+that must be easily distinguishable from token lists.
+
+@<Declare the stashing/unstashing routines@>=
+static pointer mp_stash_cur_exp (MP mp) {
+ pointer p; /* the capsule that will be returned */
+ switch (mp->cur_type) {
+ case unknown_types:
+ case mp_transform_type:
+ case mp_color_type:
+ case mp_pair_type:
+ case mp_dependent:
+ case mp_proto_dependent:
+ case mp_independent:
+ case mp_cmykcolor_type:
+ p=mp->cur_exp;
+ break;
+ default:
+ p=mp_get_node(mp, value_node_size); mp_name_type(p)=mp_capsule;
+ mp_type(p)=mp->cur_type; value(p)=mp->cur_exp;
+ break;
+ }
+ mp->cur_type=mp_vacuous; mp_link(p)=mp_void;
+ return p;
+}
+
+@ The inverse of |stash_cur_exp| is the following procedure, which
+deletes an unnecessary capsule and puts its contents into |cur_type|
+and |cur_exp|.
+
+The program steps of \MP\ can be divided into two categories: those in
+which |cur_type| and |cur_exp| are ``alive'' and those in which they are
+``dead,'' in the sense that |cur_type| and |cur_exp| contain relevant
+information or not. It's important not to ignore them when they're alive,
+and it's important not to pay attention to them when they're dead.
+
+There's also an intermediate category: If |cur_type=mp_vacuous|, then
+|cur_exp| is irrelevant, hence we can proceed without caring if |cur_type|
+and |cur_exp| are alive or dead. In such cases we say that |cur_type|
+and |cur_exp| are {\sl dormant}. It is permissible to call |get_x_next|
+only when they are alive or dormant.
+
+The \\{stash} procedure above assumes that |cur_type| and |cur_exp|
+are alive or dormant. The \\{unstash} procedure assumes that they are
+dead or dormant; it resuscitates them.
+
+@<Declare the stashing/unstashing...@>=
+static void mp_unstash_cur_exp (MP mp,pointer p) ;
+
+@ @c
+void mp_unstash_cur_exp (MP mp,pointer p) {
+ mp->cur_type=mp_type(p);
+ switch (mp->cur_type) {
+ case unknown_types:
+ case mp_transform_type:
+ case mp_color_type:
+ case mp_pair_type:
+ case mp_dependent:
+ case mp_proto_dependent:
+ case mp_independent:
+ case mp_cmykcolor_type:
+ mp->cur_exp=p;
+ break;
+ default:
+ mp->cur_exp=value(p);
+ mp_free_node(mp, p,value_node_size);
+ break;
+ }
+}
+
+@ The following procedure prints the values of expressions in an
+abbreviated format. If its first parameter |p| is null, the value of
+|(cur_type,cur_exp)| is displayed; otherwise |p| should be a capsule
+containing the desired value. The second parameter controls the amount of
+output. If it is~0, dependency lists will be abbreviated to
+`\.{linearform}' unless they consist of a single term. If it is greater
+than~1, complicated structures (pens, pictures, and paths) will be displayed
+in full.
+@.linearform@>
+
+@<Declarations@>=
+@<Declare the procedure called |print_dp|@>
+@<Declare the stashing/unstashing routines@>
+static void mp_print_exp (MP mp,pointer p, quarterword verbosity) ;
+
+@ @c
+void mp_print_exp (MP mp,pointer p, quarterword verbosity) {
+ boolean restore_cur_exp; /* should |cur_exp| be restored? */
+ quarterword t; /* the type of the expression */
+ pointer q; /* a big node being displayed */
+ integer v=0; /* the value of the expression */
+ if ( p!=null ) {
+ restore_cur_exp=false;
+ } else {
+ p=mp_stash_cur_exp(mp); restore_cur_exp=true;
+ }
+ t=mp_type(p);
+ if ( t<mp_dependent ) v=value(p); else if ( t<mp_independent ) v=dep_list(p);
+ @<Print an abbreviated value of |v| with format depending on |t|@>;
+ if ( restore_cur_exp ) mp_unstash_cur_exp(mp, p);
+}
+
+@ @<Print an abbreviated value of |v| with format depending on |t|@>=
+switch (t) {
+case mp_vacuous:mp_print(mp, "mp_vacuous"); break;
+case mp_boolean_type:
+ if ( v==true_code ) mp_print(mp, "true"); else mp_print(mp, "false");
+ break;
+case unknown_types: case mp_numeric_type:
+ @<Display a variable that's been declared but not defined@>;
+ break;
+case mp_string_type:
+ mp_print_char(mp, xord('"')); mp_print_str(mp, v); mp_print_char(mp, xord('"'));
+ break;
+case mp_pen_type: case mp_path_type: case mp_picture_type:
+ @<Display a complex type@>;
+ break;
+case mp_transform_type: case mp_color_type: case mp_pair_type: case mp_cmykcolor_type:
+ if ( v==null ) mp_print_type(mp, t);
+ else @<Display a big node@>;
+ break;
+case mp_known:mp_print_scaled(mp, v); break;
+case mp_dependent: case mp_proto_dependent:
+ mp_print_dp(mp, t,v,verbosity);
+ break;
+case mp_independent:mp_print_variable_name(mp, p); break;
+default: mp_confusion(mp, "exp"); break;
+@:this can't happen exp}{\quad exp@>
+}
+
+@ @<Display a big node@>=
+{
+ mp_print_char(mp, xord('(')); q=v+mp->big_node_size[t];
+ do {
+ if ( mp_type(v)==mp_known ) mp_print_scaled(mp, value(v));
+ else if ( mp_type(v)==mp_independent ) mp_print_variable_name(mp, v);
+ else mp_print_dp(mp, mp_type(v),dep_list(v),verbosity);
+ v=v+2;
+ if ( v!=q ) mp_print_char(mp, xord(','));
+ } while (v!=q);
+ mp_print_char(mp, xord(')'));
+}
+
+@ Values of type \&{picture}, \&{path}, and \&{pen} are displayed verbosely
+in the log file only, unless the user has given a positive value to
+\\{tracingonline}.
+
+@<Display a complex type@>=
+if ( verbosity<=1 ) {
+ mp_print_type(mp, t);
+} else {
+ if ( mp->selector==term_and_log )
+ if ( mp->internal[mp_tracing_online]<=0 ) {
+ mp->selector=term_only;
+ mp_print_type(mp, t); mp_print(mp, " (see the transcript file)");
+ mp->selector=term_and_log;
+ };
+ switch (t) {
+ case mp_pen_type:mp_print_pen(mp, v,"",false); break;
+ case mp_path_type:mp_print_path(mp, v,"",false); break;
+ case mp_picture_type:mp_print_edges(mp, v,"",false); break;
+ } /* there are no other cases */
+}
+
+@ @<Declare the procedure called |print_dp|@>=
+static void mp_print_dp (MP mp, quarterword t, pointer p,
+ quarterword verbosity) {
+ pointer q; /* the node following |p| */
+ q=mp_link(p);
+ if ( (mp_info(q)==null) || (verbosity>0) ) mp_print_dependency(mp, p,t);
+ else mp_print(mp, "linearform");
+}
+
+@ The displayed name of a variable in a ring will not be a capsule unless
+the ring consists entirely of capsules.
+
+@<Display a variable that's been declared but not defined@>=
+{ mp_print_type(mp, t);
+if ( v!=null )
+ { mp_print_char(mp, xord(' '));
+ while ( (mp_name_type(v)==mp_capsule) && (v!=p) ) v=value(v);
+ mp_print_variable_name(mp, v);
+ };
+}
+
+@ When errors are detected during parsing, it is often helpful to
+display an expression just above the error message, using |exp_err|
+or |disp_err| instead of |print_err|.
+
+@d exp_err(A) mp_disp_err(mp, null,(A)) /* displays the current expression */
+
+@<Declarations@>=
+static void mp_disp_err (MP mp,pointer p, const char *s) ;
+
+@ @c
+void mp_disp_err (MP mp,pointer p, const char *s) {
+ if ( mp->interaction==mp_error_stop_mode ) wake_up_terminal;
+ mp_print_nl(mp, ">> ");
+@.>>@>
+ mp_print_exp(mp, p,1); /* ``medium verbose'' printing of the expression */
+ if (strlen(s)>0) {
+ print_err(s);
+ }
+}
+
+@ If |cur_type| and |cur_exp| contain relevant information that should
+be recycled, we will use the following procedure, which changes |cur_type|
+to |known| and stores a given value in |cur_exp|. We can think of |cur_type|
+and |cur_exp| as either alive or dormant after this has been done,
+because |cur_exp| will not contain a pointer value.
+
+@ @c
+static void mp_flush_cur_exp (MP mp,scaled v) {
+ switch (mp->cur_type) {
+ case unknown_types: case mp_transform_type: case mp_color_type: case mp_pair_type:
+ case mp_dependent: case mp_proto_dependent: case mp_independent: case mp_cmykcolor_type:
+ mp_recycle_value(mp, mp->cur_exp);
+ mp_free_node(mp, mp->cur_exp,value_node_size);
+ break;
+ case mp_string_type:
+ delete_str_ref(mp->cur_exp); break;
+ case mp_pen_type: case mp_path_type:
+ mp_toss_knot_list(mp, mp->cur_exp); break;
+ case mp_picture_type:
+ delete_edge_ref(mp->cur_exp); break;
+ default:
+ break;
+ }
+ mp->cur_type=mp_known; mp->cur_exp=v;
+}
+
+@ There's a much more general procedure that is capable of releasing
+the storage associated with any two-word value packet.
+
+@<Declarations@>=
+static void mp_recycle_value (MP mp,pointer p) ;
+
+@ @c
+static void mp_recycle_value (MP mp,pointer p) {
+ quarterword t; /* a type code */
+ integer vv; /* another value */
+ pointer q,r,s,pp; /* link manipulation registers */
+ integer v=0; /* a value */
+ t=mp_type(p);
+ if ( t<mp_dependent ) v=value(p);
+ switch (t) {
+ case undefined: case mp_vacuous: case mp_boolean_type: case mp_known:
+ case mp_numeric_type:
+ break;
+ case unknown_types:
+ mp_ring_delete(mp, p); break;
+ case mp_string_type:
+ delete_str_ref(v); break;
+ case mp_path_type: case mp_pen_type:
+ mp_toss_knot_list(mp, v); break;
+ case mp_picture_type:
+ delete_edge_ref(v); break;
+ case mp_cmykcolor_type: case mp_pair_type: case mp_color_type:
+ case mp_transform_type:
+ @<Recycle a big node@>; break;
+ case mp_dependent: case mp_proto_dependent:
+ @<Recycle a dependency list@>; break;
+ case mp_independent:
+ @<Recycle an independent variable@>; break;
+ case mp_token_list: case mp_structured:
+ mp_confusion(mp, "recycle"); break;
+@:this can't happen recycle}{\quad recycle@>
+ case mp_unsuffixed_macro: case mp_suffixed_macro:
+ mp_delete_mac_ref(mp, value(p)); break;
+ } /* there are no other cases */
+ mp_type(p)=undefined;
+}
+
+@ @<Recycle a big node@>=
+if ( v!=null ){
+ q=v+mp->big_node_size[t];
+ do {
+ q=q-2; mp_recycle_value(mp, q);
+ } while (q!=v);
+ mp_free_node(mp, v,mp->big_node_size[t]);
+}
+
+@ @<Recycle a dependency list@>=
+{
+ q=dep_list(p);
+ while ( mp_info(q)!=null ) q=mp_link(q);
+ mp_link(prev_dep(p))=mp_link(q);
+ prev_dep(mp_link(q))=prev_dep(p);
+ mp_link(q)=null; mp_flush_node_list(mp, dep_list(p));
+}
+
+@ When an independent variable disappears, it simply fades away, unless
+something depends on it. In the latter case, a dependent variable whose
+coefficient of dependence is maximal will take its place.
+The relevant algorithm is due to Ignacio~A. Zabala, who implemented it
+as part of his Ph.D. thesis (Stanford University, December 1982).
+@^Zabala Salelles, Ignacio Andr\'es@>
+
+For example, suppose that variable $x$ is being recycled, and that the
+only variables depending on~$x$ are $y=2x+a$ and $z=x+b$. In this case
+we want to make $y$ independent and $z=.5y-.5a+b$; no other variables
+will depend on~$y$. If $\\{tracingequations}>0$ in this situation,
+we will print `\.{\#\#\# -2x=-y+a}'.
+
+There's a slight complication, however: An independent variable $x$
+can occur both in dependency lists and in proto-dependency lists.
+This makes it necessary to be careful when deciding which coefficient
+is maximal.
+
+Furthermore, this complication is not so slight when
+a proto-dependent variable is chosen to become independent. For example,
+suppose that $y=2x+100a$ is proto-dependent while $z=x+b$ is dependent;
+then we must change $z=.5y-50a+b$ to a proto-dependency, because of the
+large coefficient `50'.
+
+In order to deal with these complications without wasting too much time,
+we shall link together the occurrences of~$x$ among all the linear
+dependencies, maintaining separate lists for the dependent and
+proto-dependent cases.
+
+@<Recycle an independent variable@>=
+{
+ mp->max_c[mp_dependent]=0; mp->max_c[mp_proto_dependent]=0;
+ mp->max_link[mp_dependent]=null; mp->max_link[mp_proto_dependent]=null;
+ q=mp_link(dep_head);
+ while ( q!=dep_head ) {
+ s=value_loc(q); /* now |mp_link(s)=dep_list(q)| */
+ while (1) {
+ r=mp_link(s);
+ if ( mp_info(r)==null ) break;
+ if ( mp_info(r)!=p ) {
+ s=r;
+ } else {
+ t=mp_type(q); mp_link(s)=mp_link(r); mp_info(r)=q;
+ if ( abs(value(r))>mp->max_c[t] ) {
+ @<Record a new maximum coefficient of type |t|@>;
+ } else {
+ mp_link(r)=mp->max_link[t]; mp->max_link[t]=r;
+ }
+ }
+ }
+ q=mp_link(r);
+ }
+ if ( (mp->max_c[mp_dependent]>0)||(mp->max_c[mp_proto_dependent]>0) ) {
+ @<Choose a dependent variable to take the place of the disappearing
+ independent variable, and change all remaining dependencies
+ accordingly@>;
+ }
+}
+
+@ The code for independency removal makes use of three two-word arrays.
+
+@<Glob...@>=
+integer max_c[mp_proto_dependent+1]; /* max coefficient magnitude */
+pointer max_ptr[mp_proto_dependent+1]; /* where |p| occurs with |max_c| */
+pointer max_link[mp_proto_dependent+1]; /* other occurrences of |p| */
+
+@ @<Record a new maximum coefficient...@>=
+{
+ if ( mp->max_c[t]>0 ) {
+ mp_link(mp->max_ptr[t])=mp->max_link[t]; mp->max_link[t]=mp->max_ptr[t];
+ }
+ mp->max_c[t]=abs(value(r)); mp->max_ptr[t]=r;
+}
+
+@ @<Choose a dependent...@>=
+{
+ if ( (mp->max_c[mp_dependent] / 010000) >= mp->max_c[mp_proto_dependent] )
+ t=mp_dependent;
+ else
+ t=mp_proto_dependent;
+ @<Determine the dependency list |s| to substitute for the independent
+ variable~|p|@>;
+ t=mp_dependent+mp_proto_dependent-t; /* complement |t| */
+ if ( mp->max_c[t]>0 ) { /* we need to pick up an unchosen dependency */
+ mp_link(mp->max_ptr[t])=mp->max_link[t]; mp->max_link[t]=mp->max_ptr[t];
+ }
+ if ( t!=mp_dependent ) { @<Substitute new dependencies in place of |p|@>; }
+ else { @<Substitute new proto-dependencies in place of |p|@>;}
+ mp_flush_node_list(mp, s);
+ if ( mp->fix_needed ) mp_fix_dependencies(mp);
+ check_arith;
+}
+
+@ Let |s=max_ptr[t]|. At this point we have $|value|(s)=\pm|max_c|[t]$,
+and |mp_info(s)| points to the dependent variable~|pp| of type~|t| from
+whose dependency list we have removed node~|s|. We must reinsert
+node~|s| into the dependency list, with coefficient $-1.0$, and with
+|pp| as the new independent variable. Since |pp| will have a larger serial
+number than any other variable, we can put node |s| at the head of the
+list.
+
+@<Determine the dep...@>=
+s=mp->max_ptr[t]; pp=mp_info(s); v=value(s);
+if ( t==mp_dependent ) value(s)=-fraction_one; else value(s)=-unity;
+r=dep_list(pp); mp_link(s)=r;
+while ( mp_info(r)!=null ) r=mp_link(r);
+q=mp_link(r); mp_link(r)=null;
+prev_dep(q)=prev_dep(pp); mp_link(prev_dep(pp))=q;
+new_indep(pp);
+if ( mp->cur_exp==pp ) if ( mp->cur_type==t ) mp->cur_type=mp_independent;
+if ( mp->internal[mp_tracing_equations]>0 ) {
+ @<Show the transformed dependency@>;
+}
+
+@ Now $(-v)$ times the formerly independent variable~|p| is being replaced
+by the dependency list~|s|.
+
+@<Show the transformed...@>=
+if ( mp_interesting(mp, p) ) {
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "### ");
+@:]]]\#\#\#_}{\.{\#\#\#}@>
+ if ( v>0 ) mp_print_char(mp, xord('-'));
+ if ( t==mp_dependent ) vv=mp_round_fraction(mp, mp->max_c[mp_dependent]);
+ else vv=mp->max_c[mp_proto_dependent];
+ if ( vv!=unity ) mp_print_scaled(mp, vv);
+ mp_print_variable_name(mp, p);
+ while ( value(p) % s_scale>0 ) {
+ mp_print(mp, "*4"); value(p)=value(p)-2;
+ }
+ if ( t==mp_dependent ) mp_print_char(mp, xord('=')); else mp_print(mp, " = ");
+ mp_print_dependency(mp, s,t);
+ mp_end_diagnostic(mp, false);
+}
+
+@ Finally, there are dependent and proto-dependent variables whose
+dependency lists must be brought up to date.
+
+@<Substitute new dependencies...@>=
+for (t=mp_dependent;t<=mp_proto_dependent;t++){
+ r=mp->max_link[t];
+ while ( r!=null ) {
+ q=mp_info(r);
+ dep_list(q)=mp_p_plus_fq(mp, dep_list(q),
+ mp_make_fraction(mp, value(r),-v),s,t,mp_dependent);
+ if ( dep_list(q)==mp->dep_final ) mp_make_known(mp, q,mp->dep_final);
+ q=r; r=mp_link(r); mp_free_node(mp, q,dep_node_size);
+ }
+}
+
+@ @<Substitute new proto...@>=
+for (t=mp_dependent;t<=mp_proto_dependent;t++) {
+ r=mp->max_link[t];
+ while ( r!=null ) {
+ q=mp_info(r);
+ if ( t==mp_dependent ) { /* for safety's sake, we change |q| to |mp_proto_dependent| */
+ if ( mp->cur_exp==q ) if ( mp->cur_type==mp_dependent )
+ mp->cur_type=mp_proto_dependent;
+ dep_list(q)=mp_p_over_v(mp, dep_list(q),unity,
+ mp_dependent,mp_proto_dependent);
+ mp_type(q)=mp_proto_dependent;
+ value(r)=mp_round_fraction(mp, value(r));
+ }
+ dep_list(q)=mp_p_plus_fq(mp, dep_list(q),
+ mp_make_scaled(mp, value(r),-v),s,
+ mp_proto_dependent,mp_proto_dependent);
+ if ( dep_list(q)==mp->dep_final )
+ mp_make_known(mp, q,mp->dep_final);
+ q=r; r=mp_link(r); mp_free_node(mp, q,dep_node_size);
+ }
+}
+
+@ Here are some routines that provide handy combinations of actions
+that are often needed during error recovery. For example,
+`|flush_error|' flushes the current expression, replaces it by
+a given value, and calls |error|.
+
+Errors often are detected after an extra token has already been scanned.
+The `\\{put\_get}' routines put that token back before calling |error|;
+then they get it back again. (Or perhaps they get another token, if
+the user has changed things.)
+
+@<Declarations@>=
+static void mp_flush_error (MP mp,scaled v);
+static void mp_put_get_error (MP mp);
+static void mp_put_get_flush_error (MP mp,scaled v) ;
+
+@ @c
+void mp_flush_error (MP mp,scaled v) {
+ mp_error(mp); mp_flush_cur_exp(mp, v);
+}
+void mp_put_get_error (MP mp) {
+ mp_back_error(mp); mp_get_x_next(mp);
+}
+void mp_put_get_flush_error (MP mp,scaled v) {
+ mp_put_get_error(mp);
+ mp_flush_cur_exp(mp, v);
+}
+
+@ A global variable |var_flag| is set to a special command code
+just before \MP\ calls |scan_expression|, if the expression should be
+treated as a variable when this command code immediately follows. For
+example, |var_flag| is set to |assignment| at the beginning of a
+statement, because we want to know the {\sl location\/} of a variable at
+the left of `\.{:=}', not the {\sl value\/} of that variable.
+
+The |scan_expression| subroutine calls |scan_tertiary|,
+which calls |scan_secondary|, which calls |scan_primary|, which sets
+|var_flag:=0|. In this way each of the scanning routines ``knows''
+when it has been called with a special |var_flag|, but |var_flag| is
+usually zero.
+
+A variable preceding a command that equals |var_flag| is converted to a
+token list rather than a value. Furthermore, an `\.{=}' sign following an
+expression with |var_flag=assignment| is not considered to be a relation
+that produces boolean expressions.
+
+
+@<Glob...@>=
+int var_flag; /* command that wants a variable */
+
+@ @<Set init...@>=
+mp->var_flag=0;
+
+@* \[37] Parsing primary expressions.
+The first parsing routine, |scan_primary|, is also the most complicated one,
+since it involves so many different cases. But each case---with one
+exception---is fairly simple by itself.
+
+When |scan_primary| begins, the first token of the primary to be scanned
+should already appear in |cur_cmd|, |cur_mod|, and |cur_sym|. The values
+of |cur_type| and |cur_exp| should be either dead or dormant, as explained
+earlier. If |cur_cmd| is not between |min_primary_command| and
+|max_primary_command|, inclusive, a syntax error will be signaled.
+
+@<Declare the basic parsing subroutines@>=
+void mp_scan_primary (MP mp) {
+ pointer p,q,r; /* for list manipulation */
+ quarterword c; /* a primitive operation code */
+ int my_var_flag; /* initial value of |my_var_flag| */
+ pointer l_delim,r_delim; /* hash addresses of a delimiter pair */
+ @<Other local variables for |scan_primary|@>;
+ my_var_flag=mp->var_flag; mp->var_flag=0;
+RESTART:
+ check_arith;
+ @<Supply diagnostic information, if requested@>;
+ switch (mp->cur_cmd) {
+ case left_delimiter:
+ @<Scan a delimited primary@>; break;
+ case begin_group:
+ @<Scan a grouped primary@>; break;
+ case string_token:
+ @<Scan a string constant@>; break;
+ case numeric_token:
+ @<Scan a primary that starts with a numeric token@>; break;
+ case nullary:
+ @<Scan a nullary operation@>; break;
+ case unary: case type_name: case cycle: case plus_or_minus:
+ @<Scan a unary operation@>; break;
+ case primary_binary:
+ @<Scan a binary operation with `\&{of}' between its operands@>; break;
+ case str_op:
+ @<Convert a suffix to a string@>; break;
+ case internal_quantity:
+ @<Scan an internal numeric quantity@>; break;
+ case capsule_token:
+ mp_make_exp_copy(mp, mp->cur_mod); break;
+ case tag_token:
+ @<Scan a variable primary; |goto restart| if it turns out to be a macro@>; break;
+ default:
+ mp_bad_exp(mp, "A primary"); goto RESTART; break;
+@.A primary expression...@>
+ }
+ mp_get_x_next(mp); /* the routines |goto done| if they don't want this */
+DONE:
+ if ( mp->cur_cmd==left_bracket ) {
+ if ( mp->cur_type>=mp_known ) {
+ @<Scan a mediation construction@>;
+ }
+ }
+}
+
+
+
+@ Errors at the beginning of expressions are flagged by |bad_exp|.
+
+@c
+static void mp_bad_exp (MP mp, const char * s) {
+ int save_flag;
+ print_err(s); mp_print(mp, " expression can't begin with `");
+ mp_print_cmd_mod(mp, mp->cur_cmd,mp->cur_mod);
+ mp_print_char(mp, xord('\''));
+ help4("I'm afraid I need some sort of value in order to continue,",
+ "so I've tentatively inserted `0'. You may want to",
+ "delete this zero and insert something else;",
+ "see Chapter 27 of The METAFONTbook for an example.");
+@:METAFONTbook}{\sl The {\logos METAFONT\/}book@>
+ mp_back_input(mp); mp->cur_sym=0; mp->cur_cmd=numeric_token;
+ mp->cur_mod=0; mp_ins_error(mp);
+ save_flag=mp->var_flag; mp->var_flag=0; mp_get_x_next(mp);
+ mp->var_flag=save_flag;
+}
+
+@ @<Supply diagnostic information, if requested@>=
+#ifdef DEBUG
+if ( mp->panicking ) mp_check_mem(mp, false);
+#endif
+if ( mp->interrupt!=0 ) if ( mp->OK_to_interrupt ) {
+ mp_back_input(mp); check_interrupt; mp_get_x_next(mp);
+}
+
+@ @<Scan a delimited primary@>=
+{
+ l_delim=mp->cur_sym; r_delim=mp->cur_mod;
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( (mp->cur_cmd==comma) && (mp->cur_type>=mp_known) ) {
+ @<Scan the rest of a delimited set of numerics@>;
+ } else {
+ mp_check_delimiter(mp, l_delim,r_delim);
+ }
+}
+
+@ The |stash_in| subroutine puts the current (numeric) expression into a field
+within a ``big node.''
+
+@c
+static void mp_stash_in (MP mp,pointer p) {
+ pointer q; /* temporary register */
+ mp_type(p)=mp->cur_type;
+ if ( mp->cur_type==mp_known ) {
+ value(p)=mp->cur_exp;
+ } else {
+ if ( mp->cur_type==mp_independent ) {
+ @<Stash an independent |cur_exp| into a big node@>;
+ } else {
+ mp->mem[value_loc(p)]=mp->mem[value_loc(mp->cur_exp)];
+ /* |dep_list(p):=dep_list(cur_exp)| and |prev_dep(p):=prev_dep(cur_exp)| */
+ mp_link(prev_dep(p))=p;
+ }
+ mp_free_node(mp, mp->cur_exp,value_node_size);
+ }
+ mp->cur_type=mp_vacuous;
+}
+
+@ In rare cases the current expression can become |independent|. There
+may be many dependency lists pointing to such an independent capsule,
+so we can't simply move it into place within a big node. Instead,
+we copy it, then recycle it.
+
+@ @<Stash an independent |cur_exp|...@>=
+{
+ q=mp_single_dependency(mp, mp->cur_exp);
+ if ( q==mp->dep_final ){
+ mp_type(p)=mp_known; value(p)=0; mp_free_node(mp, q,dep_node_size);
+ } else {
+ mp_type(p)=mp_dependent; mp_new_dep(mp, p,q);
+ }
+ mp_recycle_value(mp, mp->cur_exp);
+}
+
+@ This code uses the fact that |red_part_loc| and |green_part_loc|
+are synonymous with |x_part_loc| and |y_part_loc|.
+
+@<Scan the rest of a delimited set of numerics@>=
+{
+p=mp_stash_cur_exp(mp);
+mp_get_x_next(mp); mp_scan_expression(mp);
+@<Make sure the second part of a pair or color has a numeric type@>;
+q=mp_get_node(mp, value_node_size); mp_name_type(q)=mp_capsule;
+if ( mp->cur_cmd==comma ) mp_type(q)=mp_color_type;
+else mp_type(q)=mp_pair_type;
+mp_init_big_node(mp, q); r=value(q);
+mp_stash_in(mp, y_part_loc(r));
+mp_unstash_cur_exp(mp, p);
+mp_stash_in(mp, x_part_loc(r));
+if ( mp->cur_cmd==comma ) {
+ @<Scan the last of a triplet of numerics@>;
+}
+if ( mp->cur_cmd==comma ) {
+ mp_type(q)=mp_cmykcolor_type;
+ mp_init_big_node(mp, q); t=value(q);
+ mp->mem[cyan_part_loc(t)]=mp->mem[red_part_loc(r)];
+ value(cyan_part_loc(t))=value(red_part_loc(r));
+ mp->mem[magenta_part_loc(t)]=mp->mem[green_part_loc(r)];
+ value(magenta_part_loc(t))=value(green_part_loc(r));
+ mp->mem[yellow_part_loc(t)]=mp->mem[blue_part_loc(r)];
+ value(yellow_part_loc(t))=value(blue_part_loc(r));
+ mp_recycle_value(mp, r);
+ r=t;
+ @<Scan the last of a quartet of numerics@>;
+}
+mp_check_delimiter(mp, l_delim,r_delim);
+mp->cur_type=mp_type(q);
+mp->cur_exp=q;
+}
+
+@ @<Make sure the second part of a pair or color has a numeric type@>=
+if ( mp->cur_type<mp_known ) {
+ exp_err("Nonnumeric ypart has been replaced by 0");
+@.Nonnumeric...replaced by 0@>
+ help4("I've started to scan a pair `(a,b)' or a color `(a,b,c)';",
+ "but after finding a nice `a' I found a `b' that isn't",
+ "of numeric type. So I've changed that part to zero.",
+ "(The b that I didn't like appears above the error message.)");
+ mp_put_get_flush_error(mp, 0);
+}
+
+@ @<Scan the last of a triplet of numerics@>=
+{
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type<mp_known ) {
+ exp_err("Nonnumeric third part has been replaced by 0");
+@.Nonnumeric...replaced by 0@>
+ help3("I've just scanned a color `(a,b,c)' or cmykcolor(a,b,c,d); but the `c'",
+ "isn't of numeric type. So I've changed that part to zero.",
+ "(The c that I didn't like appears above the error message.)");
+ mp_put_get_flush_error(mp, 0);
+ }
+ mp_stash_in(mp, blue_part_loc(r));
+}
+
+@ @<Scan the last of a quartet of numerics@>=
+{
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type<mp_known ) {
+ exp_err("Nonnumeric blackpart has been replaced by 0");
+@.Nonnumeric...replaced by 0@>
+ help3("I've just scanned a cmykcolor `(c,m,y,k)'; but the `k' isn't",
+ "of numeric type. So I've changed that part to zero.",
+ "(The k that I didn't like appears above the error message.)");
+ mp_put_get_flush_error(mp, 0);
+ }
+ mp_stash_in(mp, black_part_loc(r));
+}
+
+@ The local variable |group_line| keeps track of the line
+where a \&{begingroup} command occurred; this will be useful
+in an error message if the group doesn't actually end.
+
+@<Other local variables for |scan_primary|@>=
+integer group_line; /* where a group began */
+
+@ @<Scan a grouped primary@>=
+{
+ group_line=mp_true_line(mp);
+ if ( mp->internal[mp_tracing_commands]>0 ) show_cur_cmd_mod;
+ save_boundary_item(p);
+ do {
+ mp_do_statement(mp); /* ends with |cur_cmd>=semicolon| */
+ } while (mp->cur_cmd==semicolon);
+ if ( mp->cur_cmd!=end_group ) {
+ print_err("A group begun on line ");
+@.A group...never ended@>
+ mp_print_int(mp, group_line);
+ mp_print(mp, " never ended");
+ help2("I saw a `begingroup' back there that hasn't been matched",
+ "by `endgroup'. So I've inserted `endgroup' now.");
+ mp_back_error(mp); mp->cur_cmd=end_group;
+ }
+ mp_unsave(mp);
+ /* this might change |cur_type|, if independent variables are recycled */
+ if ( mp->internal[mp_tracing_commands]>0 ) show_cur_cmd_mod;
+}
+
+@ @<Scan a string constant@>=
+{
+ mp->cur_type=mp_string_type; mp->cur_exp=mp->cur_mod;
+}
+
+@ Later we'll come to procedures that perform actual operations like
+addition, square root, and so on; our purpose now is to do the parsing.
+But we might as well mention those future procedures now, so that the
+suspense won't be too bad:
+
+\smallskip
+|do_nullary(c)| does primitive operations that have no operands (e.g.,
+`\&{true}' or `\&{pencircle}');
+
+\smallskip
+|do_unary(c)| applies a primitive operation to the current expression;
+
+\smallskip
+|do_binary(p,c)| applies a primitive operation to the capsule~|p|
+and the current expression.
+
+@<Scan a nullary operation@>=mp_do_nullary(mp, mp->cur_mod)
+
+@ @<Scan a unary operation@>=
+{
+ c=mp->cur_mod; mp_get_x_next(mp); mp_scan_primary(mp);
+ mp_do_unary(mp, c); goto DONE;
+}
+
+@ A numeric token might be a primary by itself, or it might be the
+numerator of a fraction composed solely of numeric tokens, or it might
+multiply the primary that follows (provided that the primary doesn't begin
+with a plus sign or a minus sign). The code here uses the facts that
+|max_primary_command=plus_or_minus| and
+|max_primary_command-1=numeric_token|. If a fraction is found that is less
+than unity, we try to retain higher precision when we use it in scalar
+multiplication.
+
+@<Other local variables for |scan_primary|@>=
+scaled num,denom; /* for primaries that are fractions, like `1/2' */
+
+@ @<Scan a primary that starts with a numeric token@>=
+{
+ mp->cur_exp=mp->cur_mod; mp->cur_type=mp_known; mp_get_x_next(mp);
+ if ( mp->cur_cmd!=slash ) {
+ num=0; denom=0;
+ } else {
+ mp_get_x_next(mp);
+ if ( mp->cur_cmd!=numeric_token ) {
+ mp_back_input(mp);
+ mp->cur_cmd=slash; mp->cur_mod=over; mp->cur_sym=frozen_slash;
+ goto DONE;
+ }
+ num=mp->cur_exp; denom=mp->cur_mod;
+ if ( denom==0 ) { @<Protest division by zero@>; }
+ else { mp->cur_exp=mp_make_scaled(mp, num,denom); }
+ check_arith; mp_get_x_next(mp);
+ }
+ if ( mp->cur_cmd>=min_primary_command ) {
+ if ( mp->cur_cmd<numeric_token ) { /* in particular, |cur_cmd<>plus_or_minus| */
+ p=mp_stash_cur_exp(mp); mp_scan_primary(mp);
+ if ( (abs(num)>=abs(denom))||(mp->cur_type<mp_color_type) ) {
+ mp_do_binary(mp, p,times);
+ } else {
+ mp_frac_mult(mp, num,denom);
+ mp_free_node(mp, p,value_node_size);
+ }
+ }
+ }
+ goto DONE;
+}
+
+@ @<Protest division...@>=
+{
+ print_err("Division by zero");
+@.Division by zero@>
+ help1("I'll pretend that you meant to divide by 1."); mp_error(mp);
+}
+
+@ @<Scan a binary operation with `\&{of}' between its operands@>=
+{
+ c=mp->cur_mod; mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_cmd!=of_token ) {
+ mp_missing_err(mp, "of"); mp_print(mp, " for ");
+ mp_print_cmd_mod(mp, primary_binary,c);
+@.Missing `of'@>
+ help1("I've got the first argument; will look now for the other.");
+ mp_back_error(mp);
+ }
+ p=mp_stash_cur_exp(mp); mp_get_x_next(mp); mp_scan_primary(mp);
+ mp_do_binary(mp, p,c); goto DONE;
+}
+
+@ @<Convert a suffix to a string@>=
+{
+ mp_get_x_next(mp); mp_scan_suffix(mp);
+ mp->old_setting=mp->selector; mp->selector=new_string;
+ mp_show_token_list(mp, mp->cur_exp,null,100000,0);
+ mp_flush_token_list(mp, mp->cur_exp);
+ mp->cur_exp=mp_make_string(mp); mp->selector=mp->old_setting;
+ mp->cur_type=mp_string_type;
+ goto DONE;
+}
+
+@ If an internal quantity appears all by itself on the left of an
+assignment, we return a token list of length one, containing the address
+of the internal quantity plus |hash_end|. (This accords with the conventions
+of the save stack, as described earlier.)
+
+@<Scan an internal...@>=
+{
+ q=mp->cur_mod;
+ if ( my_var_flag==assignment ) {
+ mp_get_x_next(mp);
+ if ( mp->cur_cmd==assignment ) {
+ mp->cur_exp=mp_get_avail(mp);
+ mp_info(mp->cur_exp)=q+hash_end; mp->cur_type=mp_token_list;
+ goto DONE;
+ }
+ mp_back_input(mp);
+ }
+ mp->cur_type=mp_known; mp->cur_exp=mp->internal[q];
+ if (q == mp_output_format || q == mp_output_template)
+ mp->cur_type=mp_string_type;
+}
+
+@ The most difficult part of |scan_primary| has been saved for last, since
+it was necessary to build up some confidence first. We can now face the task
+of scanning a variable.
+
+As we scan a variable, we build a token list containing the relevant
+names and subscript values, simultaneously following along in the
+``collective'' structure to see if we are actually dealing with a macro
+instead of a value.
+
+The local variables |pre_head| and |post_head| will point to the beginning
+of the prefix and suffix lists; |tail| will point to the end of the list
+that is currently growing.
+
+Another local variable, |tt|, contains partial information about the
+declared type of the variable-so-far. If |tt>=mp_unsuffixed_macro|, the
+relation |tt=mp_type(q)| will always hold. If |tt=undefined|, the routine
+doesn't bother to update its information about type. And if
+|undefined<tt<mp_unsuffixed_macro|, the precise value of |tt| isn't critical.
+
+@ @<Other local variables for |scan_primary|@>=
+pointer pre_head,post_head,tail;
+ /* prefix and suffix list variables */
+quarterword tt; /* approximation to the type of the variable-so-far */
+pointer t; /* a token */
+pointer macro_ref = 0; /* reference count for a suffixed macro */
+
+@ @<Scan a variable primary...@>=
+{
+ fast_get_avail(pre_head); tail=pre_head; post_head=null; tt=mp_vacuous;
+ while (1) {
+ t=mp_cur_tok(mp); mp_link(tail)=t;
+ if ( tt!=undefined ) {
+ @<Find the approximate type |tt| and corresponding~|q|@>;
+ if ( tt>=mp_unsuffixed_macro ) {
+ @<Either begin an unsuffixed macro call or
+ prepare for a suffixed one@>;
+ }
+ }
+ mp_get_x_next(mp); tail=t;
+ if ( mp->cur_cmd==left_bracket ) {
+ @<Scan for a subscript; replace |cur_cmd| by |numeric_token| if found@>;
+ }
+ if ( mp->cur_cmd>max_suffix_token ) break;
+ if ( mp->cur_cmd<min_suffix_token ) break;
+ } /* now |cur_cmd| is |internal_quantity|, |tag_token|, or |numeric_token| */
+ @<Handle unusual cases that masquerade as variables, and |goto restart|
+ or |goto done| if appropriate;
+ otherwise make a copy of the variable and |goto done|@>;
+}
+
+@ @<Either begin an unsuffixed macro call or...@>=
+{
+ mp_link(tail)=null;
+ if ( tt>mp_unsuffixed_macro ) { /* |tt=mp_suffixed_macro| */
+ post_head=mp_get_avail(mp); tail=post_head; mp_link(tail)=t;
+ tt=undefined; macro_ref=value(q); add_mac_ref(macro_ref);
+ } else {
+ @<Set up unsuffixed macro call and |goto restart|@>;
+ }
+}
+
+@ @<Scan for a subscript; replace |cur_cmd| by |numeric_token| if found@>=
+{
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_cmd!=right_bracket ) {
+ @<Put the left bracket and the expression back to be rescanned@>;
+ } else {
+ if ( mp->cur_type!=mp_known ) mp_bad_subscript(mp);
+ mp->cur_cmd=numeric_token; mp->cur_mod=mp->cur_exp; mp->cur_sym=0;
+ }
+}
+
+@ The left bracket that we thought was introducing a subscript might have
+actually been the left bracket in a mediation construction like `\.{x[a,b]}'.
+So we don't issue an error message at this point; but we do want to back up
+so as to avoid any embarrassment about our incorrect assumption.
+
+@<Put the left bracket and the expression back to be rescanned@>=
+{
+ mp_back_input(mp); /* that was the token following the current expression */
+ mp_back_expr(mp); mp->cur_cmd=left_bracket;
+ mp->cur_mod=0; mp->cur_sym=frozen_left_bracket;
+}
+
+@ Here's a routine that puts the current expression back to be read again.
+
+@c
+static void mp_back_expr (MP mp) {
+ pointer p; /* capsule token */
+ p=mp_stash_cur_exp(mp); mp_link(p)=null; back_list(p);
+}
+
+@ Unknown subscripts lead to the following error message.
+
+@c
+static void mp_bad_subscript (MP mp) {
+ exp_err("Improper subscript has been replaced by zero");
+@.Improper subscript...@>
+ help3("A bracketed subscript must have a known numeric value;",
+ "unfortunately, what I found was the value that appears just",
+ "above this error message. So I'll try a zero subscript.");
+ mp_flush_error(mp, 0);
+}
+
+@ Every time we call |get_x_next|, there's a chance that the variable we've
+been looking at will disappear. Thus, we cannot safely keep |q| pointing
+into the variable structure; we need to start searching from the root each time.
+
+@<Find the approximate type |tt| and corresponding~|q|@>=
+@^inner loop@>
+{
+ p=mp_link(pre_head); q=mp_info(p); tt=undefined;
+ if ( eq_type(q) % outer_tag==tag_token ) {
+ q=equiv(q);
+ if ( q==null ) goto DONE2;
+ while (1) {
+ p=mp_link(p);
+ if ( p==null ) {
+ tt=mp_type(q); goto DONE2;
+ };
+ if ( mp_type(q)!=mp_structured ) goto DONE2;
+ q=mp_link(attr_head(q)); /* the |collective_subscript| attribute */
+ if ( p>=mp->hi_mem_min ) { /* it's not a subscript */
+ do { q=mp_link(q); } while (! (attr_loc(q)>=mp_info(p)));
+ if ( attr_loc(q)>mp_info(p) ) goto DONE2;
+ }
+ }
+ }
+DONE2:
+ ;
+}
+
+@ How do things stand now? Well, we have scanned an entire variable name,
+including possible subscripts and/or attributes; |cur_cmd|, |cur_mod|, and
+|cur_sym| represent the token that follows. If |post_head=null|, a
+token list for this variable name starts at |mp_link(pre_head)|, with all
+subscripts evaluated. But if |post_head<>null|, the variable turned out
+to be a suffixed macro; |pre_head| is the head of the prefix list, while
+|post_head| is the head of a token list containing both `\.{\AT!}' and
+the suffix.
+
+Our immediate problem is to see if this variable still exists. (Variable
+structures can change drastically whenever we call |get_x_next|; users
+aren't supposed to do this, but the fact that it is possible means that
+we must be cautious.)
+
+The following procedure prints an error message when a variable
+unexpectedly disappears. Its help message isn't quite right for
+our present purposes, but we'll be able to fix that up.
+
+@c
+static void mp_obliterated (MP mp,pointer q) {
+ print_err("Variable "); mp_show_token_list(mp, q,null,1000,0);
+ mp_print(mp, " has been obliterated");
+@.Variable...obliterated@>
+ help5("It seems you did a nasty thing---probably by accident,",
+ "but nevertheless you nearly hornswoggled me...",
+ "While I was evaluating the right-hand side of this",
+ "command, something happened, and the left-hand side",
+ "is no longer a variable! So I won't change anything.");
+}
+
+@ If the variable does exist, we also need to check
+for a few other special cases before deciding that a plain old ordinary
+variable has, indeed, been scanned.
+
+@<Handle unusual cases that masquerade as variables...@>=
+if ( post_head!=null ) {
+ @<Set up suffixed macro call and |goto restart|@>;
+}
+q=mp_link(pre_head); free_avail(pre_head);
+if ( mp->cur_cmd==my_var_flag ) {
+ mp->cur_type=mp_token_list; mp->cur_exp=q; goto DONE;
+}
+p=mp_find_variable(mp, q);
+if ( p!=null ) {
+ mp_make_exp_copy(mp, p);
+} else {
+ mp_obliterated(mp, q);
+ mp->help_line[2]="While I was evaluating the suffix of this variable,";
+ mp->help_line[1]="something was redefined, and it's no longer a variable!";
+ mp->help_line[0]="In order to get back on my feet, I've inserted `0' instead.";
+ mp_put_get_flush_error(mp, 0);
+}
+mp_flush_node_list(mp, q);
+goto DONE
+
+@ The only complication associated with macro calling is that the prefix
+and ``at'' parameters must be packaged in an appropriate list of lists.
+
+@<Set up unsuffixed macro call and |goto restart|@>=
+{
+ p=mp_get_avail(mp); mp_info(pre_head)=mp_link(pre_head); mp_link(pre_head)=p;
+ mp_info(p)=t; mp_macro_call(mp, value(q),pre_head,null);
+ mp_get_x_next(mp);
+ goto RESTART;
+}
+
+@ If the ``variable'' that turned out to be a suffixed macro no longer exists,
+we don't care, because we have reserved a pointer (|macro_ref|) to its
+token list.
+
+@<Set up suffixed macro call and |goto restart|@>=
+{
+ mp_back_input(mp); p=mp_get_avail(mp); q=mp_link(post_head);
+ mp_info(pre_head)=mp_link(pre_head); mp_link(pre_head)=post_head;
+ mp_info(post_head)=q; mp_link(post_head)=p; mp_info(p)=mp_link(q); mp_link(q)=null;
+ mp_macro_call(mp, macro_ref,pre_head,null); decr(ref_count(macro_ref));
+ mp_get_x_next(mp); goto RESTART;
+}
+
+@ Our remaining job is simply to make a copy of the value that has been
+found. Some cases are harder than others, but complexity arises solely
+because of the multiplicity of possible cases.
+
+@<Declare the procedure called |make_exp_copy|@>=
+@<Declare subroutines needed by |make_exp_copy|@>
+static void mp_make_exp_copy (MP mp,pointer p) {
+ pointer q,r,t; /* registers for list manipulation */
+RESTART:
+ mp->cur_type=mp_type(p);
+ switch (mp->cur_type) {
+ case mp_vacuous: case mp_boolean_type: case mp_known:
+ mp->cur_exp=value(p); break;
+ case unknown_types:
+ mp->cur_exp=mp_new_ring_entry(mp, p);
+ break;
+ case mp_string_type:
+ mp->cur_exp=value(p); add_str_ref(mp->cur_exp);
+ break;
+ case mp_picture_type:
+ mp->cur_exp=value(p);add_edge_ref(mp->cur_exp);
+ break;
+ case mp_pen_type:
+ mp->cur_exp=copy_pen(value(p));
+ break;
+ case mp_path_type:
+ mp->cur_exp=mp_copy_path(mp, value(p));
+ break;
+ case mp_transform_type: case mp_color_type:
+ case mp_cmykcolor_type: case mp_pair_type:
+ @<Copy the big node |p|@>;
+ break;
+ case mp_dependent: case mp_proto_dependent:
+ mp_encapsulate(mp, mp_copy_dep_list(mp, dep_list(p)));
+ break;
+ case mp_numeric_type:
+ new_indep(p); goto RESTART;
+ break;
+ case mp_independent:
+ q=mp_single_dependency(mp, p);
+ if ( q==mp->dep_final ){
+ mp->cur_type=mp_known; mp->cur_exp=0; mp_free_node(mp, q,dep_node_size);
+ } else {
+ mp->cur_type=mp_dependent; mp_encapsulate(mp, q);
+ }
+ break;
+ default:
+ mp_confusion(mp, "copy");
+@:this can't happen copy}{\quad copy@>
+ break;
+ }
+}
+
+@ The |encapsulate| subroutine assumes that |dep_final| is the
+tail of dependency list~|p|.
+
+@<Declare subroutines needed by |make_exp_copy|@>=
+static void mp_encapsulate (MP mp,pointer p) {
+ mp->cur_exp=mp_get_node(mp, value_node_size); mp_type(mp->cur_exp)=mp->cur_type;
+ mp_name_type(mp->cur_exp)=mp_capsule; mp_new_dep(mp, mp->cur_exp,p);
+}
+
+@ The most tedious case arises when the user refers to a
+\&{pair}, \&{color}, or \&{transform} variable; we must copy several fields,
+each of which can be |independent|, |dependent|, |mp_proto_dependent|,
+or |known|.
+
+@<Copy the big node |p|@>=
+{
+ if ( value(p)==null )
+ mp_init_big_node(mp, p);
+ t=mp_get_node(mp, value_node_size); mp_name_type(t)=mp_capsule; mp_type(t)=mp->cur_type;
+ mp_init_big_node(mp, t);
+ q=value(p)+mp->big_node_size[mp->cur_type];
+ r=value(t)+mp->big_node_size[mp->cur_type];
+ do {
+ q=q-2; r=r-2; mp_install(mp, r,q);
+ } while (q!=value(p));
+ mp->cur_exp=t;
+}
+
+@ The |install| procedure copies a numeric field~|q| into field~|r| of
+a big node that will be part of a capsule.
+
+@<Declare subroutines needed by |make_exp_copy|@>=
+static void mp_install (MP mp,pointer r, pointer q) {
+ pointer p; /* temporary register */
+ if ( mp_type(q)==mp_known ){
+ value(r)=value(q); mp_type(r)=mp_known;
+ } else if ( mp_type(q)==mp_independent ) {
+ p=mp_single_dependency(mp, q);
+ if ( p==mp->dep_final ) {
+ mp_type(r)=mp_known; value(r)=0; mp_free_node(mp, p,dep_node_size);
+ } else {
+ mp_type(r)=mp_dependent; mp_new_dep(mp, r,p);
+ }
+ } else {
+ mp_type(r)=mp_type(q); mp_new_dep(mp, r,mp_copy_dep_list(mp, dep_list(q)));
+ }
+}
+
+@ Expressions of the form `\.{a[b,c]}' are converted into
+`\.{b+a*(c-b)}', without checking the types of \.b~or~\.c,
+provided that \.a is numeric.
+
+@<Scan a mediation...@>=
+{
+ p=mp_stash_cur_exp(mp); mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_cmd!=comma ) {
+ @<Put the left bracket and the expression back...@>;
+ mp_unstash_cur_exp(mp, p);
+ } else {
+ q=mp_stash_cur_exp(mp); mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_cmd!=right_bracket ) {
+ mp_missing_err(mp, "]");
+@.Missing `]'@>
+ help3("I've scanned an expression of the form `a[b,c',",
+ "so a right bracket should have come next.",
+ "I shall pretend that one was there.");
+ mp_back_error(mp);
+ }
+ r=mp_stash_cur_exp(mp); mp_make_exp_copy(mp, q);
+ mp_do_binary(mp, r,minus); mp_do_binary(mp, p,times);
+ mp_do_binary(mp, q,plus); mp_get_x_next(mp);
+ }
+}
+
+@ Here is a comparatively simple routine that is used to scan the
+\&{suffix} parameters of a macro.
+
+@<Declare the basic parsing subroutines@>=
+static void mp_scan_suffix (MP mp) {
+ pointer h,t; /* head and tail of the list being built */
+ pointer p; /* temporary register */
+ h=mp_get_avail(mp); t=h;
+ while (1) {
+ if ( mp->cur_cmd==left_bracket ) {
+ @<Scan a bracketed subscript and set |cur_cmd:=numeric_token|@>;
+ }
+ if ( mp->cur_cmd==numeric_token ) {
+ p=mp_new_num_tok(mp, mp->cur_mod);
+ } else if ((mp->cur_cmd==tag_token)||(mp->cur_cmd==internal_quantity) ) {
+ p=mp_get_avail(mp); mp_info(p)=mp->cur_sym;
+ } else {
+ break;
+ }
+ mp_link(t)=p; t=p; mp_get_x_next(mp);
+ }
+ mp->cur_exp=mp_link(h); free_avail(h); mp->cur_type=mp_token_list;
+}
+
+@ @<Scan a bracketed subscript and set |cur_cmd:=numeric_token|@>=
+{
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_known ) mp_bad_subscript(mp);
+ if ( mp->cur_cmd!=right_bracket ) {
+ mp_missing_err(mp, "]");
+@.Missing `]'@>
+ help3("I've seen a `[' and a subscript value, in a suffix,",
+ "so a right bracket should have come next.",
+ "I shall pretend that one was there.");
+ mp_back_error(mp);
+ }
+ mp->cur_cmd=numeric_token; mp->cur_mod=mp->cur_exp;
+}
+
+@* \[38] Parsing secondary and higher expressions.
+
+After the intricacies of |scan_primary|\kern-1pt,
+the |scan_secondary| routine is
+refreshingly simple. It's not trivial, but the operations are relatively
+straightforward; the main difficulty is, again, that expressions and data
+structures might change drastically every time we call |get_x_next|, so a
+cautious approach is mandatory. For example, a macro defined by
+\&{primarydef} might have disappeared by the time its second argument has
+been scanned; we solve this by increasing the reference count of its token
+list, so that the macro can be called even after it has been clobbered.
+
+@<Declare the basic parsing subroutines@>=
+static void mp_scan_secondary (MP mp) {
+ pointer p; /* for list manipulation */
+ halfword c,d; /* operation codes or modifiers */
+ pointer mac_name; /* token defined with \&{primarydef} */
+RESTART:
+ if ((mp->cur_cmd<min_primary_command)||
+ (mp->cur_cmd>max_primary_command) )
+ mp_bad_exp(mp, "A secondary");
+@.A secondary expression...@>
+ mp_scan_primary(mp);
+CONTINUE:
+ if ( mp->cur_cmd<=max_secondary_command &&
+ mp->cur_cmd>=min_secondary_command ) {
+ p=mp_stash_cur_exp(mp);
+ c=mp->cur_mod; d=mp->cur_cmd;
+ if ( d==secondary_primary_macro ) {
+ mac_name=mp->cur_sym;
+ add_mac_ref(c);
+ }
+ mp_get_x_next(mp);
+ mp_scan_primary(mp);
+ if ( d!=secondary_primary_macro ) {
+ mp_do_binary(mp, p,c);
+ } else {
+ mp_back_input(mp);
+ mp_binary_mac(mp, p,c,mac_name);
+ decr(ref_count(c));
+ mp_get_x_next(mp);
+ goto RESTART;
+ }
+ goto CONTINUE;
+ }
+}
+
+@ The following procedure calls a macro that has two parameters,
+|p| and |cur_exp|.
+
+@c
+static void mp_binary_mac (MP mp,pointer p, pointer c, pointer n) {
+ pointer q,r; /* nodes in the parameter list */
+ q=mp_get_avail(mp); r=mp_get_avail(mp); mp_link(q)=r;
+ mp_info(q)=p; mp_info(r)=mp_stash_cur_exp(mp);
+ mp_macro_call(mp, c,q,n);
+}
+
+@ The next procedure, |scan_tertiary|, is pretty much the same deal.
+
+@<Declare the basic parsing subroutines@>=
+static void mp_scan_tertiary (MP mp) {
+ pointer p; /* for list manipulation */
+ halfword c,d; /* operation codes or modifiers */
+ pointer mac_name; /* token defined with \&{secondarydef} */
+RESTART:
+ if ((mp->cur_cmd<min_primary_command)||
+ (mp->cur_cmd>max_primary_command) )
+ mp_bad_exp(mp, "A tertiary");
+@.A tertiary expression...@>
+ mp_scan_secondary(mp);
+CONTINUE:
+ if ( mp->cur_cmd<=max_tertiary_command ) {
+ if ( mp->cur_cmd>=min_tertiary_command ) {
+ p=mp_stash_cur_exp(mp); c=mp->cur_mod; d=mp->cur_cmd;
+ if ( d==tertiary_secondary_macro ) {
+ mac_name=mp->cur_sym; add_mac_ref(c);
+ };
+ mp_get_x_next(mp); mp_scan_secondary(mp);
+ if ( d!=tertiary_secondary_macro ) {
+ mp_do_binary(mp, p,c);
+ } else {
+ mp_back_input(mp); mp_binary_mac(mp, p,c,mac_name);
+ decr(ref_count(c)); mp_get_x_next(mp);
+ goto RESTART;
+ }
+ goto CONTINUE;
+ }
+ }
+}
+
+@ Finally we reach the deepest level in our quartet of parsing routines.
+This one is much like the others; but it has an extra complication from
+paths, which materialize here.
+
+@d continue_path 25 /* a label inside of |scan_expression| */
+@d finish_path 26 /* another */
+
+@<Declare the basic parsing subroutines@>=
+static void mp_scan_expression (MP mp) {
+ pointer p,q,r,pp,qq; /* for list manipulation */
+ halfword c,d; /* operation codes or modifiers */
+ int my_var_flag; /* initial value of |var_flag| */
+ pointer mac_name; /* token defined with \&{tertiarydef} */
+ boolean cycle_hit; /* did a path expression just end with `\&{cycle}'? */
+ scaled x,y; /* explicit coordinates or tension at a path join */
+ int t; /* knot type following a path join */
+ t=0; y=0; x=0;
+ my_var_flag=mp->var_flag; mac_name=null;
+RESTART:
+ if ((mp->cur_cmd<min_primary_command)||
+ (mp->cur_cmd>max_primary_command) )
+ mp_bad_exp(mp, "An");
+@.An expression...@>
+ mp_scan_tertiary(mp);
+CONTINUE:
+ if ( mp->cur_cmd<=max_expression_command )
+ if ( mp->cur_cmd>=min_expression_command ) {
+ if ( (mp->cur_cmd!=equals)||(my_var_flag!=assignment) ) {
+ p=mp_stash_cur_exp(mp); c=mp->cur_mod; d=mp->cur_cmd;
+ if ( d==expression_tertiary_macro ) {
+ mac_name=mp->cur_sym; add_mac_ref(c);
+ }
+ if ( (d<ampersand)||((d==ampersand)&&
+ ((mp_type(p)==mp_pair_type)||(mp_type(p)==mp_path_type))) ) {
+ @<Scan a path construction operation;
+ but |return| if |p| has the wrong type@>;
+ } else {
+ mp_get_x_next(mp); mp_scan_tertiary(mp);
+ if ( d!=expression_tertiary_macro ) {
+ mp_do_binary(mp, p,c);
+ } else {
+ mp_back_input(mp); mp_binary_mac(mp, p,c,mac_name);
+ decr(ref_count(c)); mp_get_x_next(mp);
+ goto RESTART;
+ }
+ }
+ goto CONTINUE;
+ }
+ }
+}
+
+@ The reader should review the data structure conventions for paths before
+hoping to understand the next part of this code.
+
+@<Scan a path construction operation...@>=
+{
+ cycle_hit=false;
+ @<Convert the left operand, |p|, into a partial path ending at~|q|;
+ but |return| if |p| doesn't have a suitable type@>;
+CONTINUE_PATH:
+ @<Determine the path join parameters;
+ but |goto finish_path| if there's only a direction specifier@>;
+ if ( mp->cur_cmd==cycle ) {
+ @<Get ready to close a cycle@>;
+ } else {
+ mp_scan_tertiary(mp);
+ @<Convert the right operand, |cur_exp|,
+ into a partial path from |pp| to~|qq|@>;
+ }
+ @<Join the partial paths and reset |p| and |q| to the head and tail
+ of the result@>;
+ if ( mp->cur_cmd>=min_expression_command )
+ if ( mp->cur_cmd<=ampersand ) if ( ! cycle_hit ) goto CONTINUE_PATH;
+FINISH_PATH:
+ @<Choose control points for the path and put the result into |cur_exp|@>;
+}
+
+@ @<Convert the left operand, |p|, into a partial path ending at~|q|...@>=
+{
+ mp_unstash_cur_exp(mp, p);
+ if ( mp->cur_type==mp_pair_type ) p=mp_new_knot(mp);
+ else if ( mp->cur_type==mp_path_type ) p=mp->cur_exp;
+ else return;
+ q=p;
+ while ( mp_link(q)!=p ) q=mp_link(q);
+ if ( mp_left_type(p)!=mp_endpoint ) { /* open up a cycle */
+ r=mp_copy_knot(mp, p); mp_link(q)=r; q=r;
+ }
+ mp_left_type(p)=mp_open; mp_right_type(q)=mp_open;
+}
+
+@ A pair of numeric values is changed into a knot node for a one-point path
+when \MP\ discovers that the pair is part of a path.
+
+@c
+static pointer mp_new_knot (MP mp) { /* convert a pair to a knot with two endpoints */
+ pointer q; /* the new node */
+ q=mp_get_node(mp, knot_node_size); mp_left_type(q)=mp_endpoint;
+ mp_right_type(q)=mp_endpoint; mp_originator(q)=mp_metapost_user; mp_link(q)=q;
+ mp_known_pair(mp); mp_x_coord(q)=mp->cur_x; mp_y_coord(q)=mp->cur_y;
+ return q;
+}
+
+@ The |known_pair| subroutine sets |cur_x| and |cur_y| to the components
+of the current expression, assuming that the current expression is a
+pair of known numerics. Unknown components are zeroed, and the
+current expression is flushed.
+
+@<Declarations@>=
+static void mp_known_pair (MP mp);
+
+@ @c
+void mp_known_pair (MP mp) {
+ pointer p; /* the pair node */
+ if ( mp->cur_type!=mp_pair_type ) {
+ exp_err("Undefined coordinates have been replaced by (0,0)");
+@.Undefined coordinates...@>
+ help5("I need x and y numbers for this part of the path.",
+ "The value I found (see above) was no good;",
+ "so I'll try to keep going by using zero instead.",
+ "(Chapter 27 of The METAFONTbook explains that",
+@:METAFONTbook}{\sl The {\logos METAFONT\/}book@>
+ "you might want to type `I ??" "?' now.)");
+ mp_put_get_flush_error(mp, 0); mp->cur_x=0; mp->cur_y=0;
+ } else {
+ p=value(mp->cur_exp);
+ @<Make sure that both |x| and |y| parts of |p| are known;
+ copy them into |cur_x| and |cur_y|@>;
+ mp_flush_cur_exp(mp, 0);
+ }
+}
+
+@ @<Make sure that both |x| and |y| parts of |p| are known...@>=
+if ( mp_type(x_part_loc(p))==mp_known ) {
+ mp->cur_x=value(x_part_loc(p));
+} else {
+ mp_disp_err(mp, x_part_loc(p),
+ "Undefined x coordinate has been replaced by 0");
+@.Undefined coordinates...@>
+ help5("I need a `known' x value for this part of the path.",
+ "The value I found (see above) was no good;",
+ "so I'll try to keep going by using zero instead.",
+ "(Chapter 27 of The METAFONTbook explains that",
+@:METAFONTbook}{\sl The {\logos METAFONT\/}book@>
+ "you might want to type `I ??" "?' now.)");
+ mp_put_get_error(mp); mp_recycle_value(mp, x_part_loc(p)); mp->cur_x=0;
+}
+if ( mp_type(y_part_loc(p))==mp_known ) {
+ mp->cur_y=value(y_part_loc(p));
+} else {
+ mp_disp_err(mp, y_part_loc(p),
+ "Undefined y coordinate has been replaced by 0");
+ help5("I need a `known' y value for this part of the path.",
+ "The value I found (see above) was no good;",
+ "so I'll try to keep going by using zero instead.",
+ "(Chapter 27 of The METAFONTbook explains that",
+ "you might want to type `I ??" "?' now.)");
+ mp_put_get_error(mp); mp_recycle_value(mp, y_part_loc(p)); mp->cur_y=0;
+}
+
+@ At this point |cur_cmd| is either |ampersand|, |left_brace|, or |path_join|.
+
+@<Determine the path join parameters...@>=
+if ( mp->cur_cmd==left_brace ) {
+ @<Put the pre-join direction information into node |q|@>;
+}
+d=mp->cur_cmd;
+if ( d==path_join ) {
+ @<Determine the tension and/or control points@>;
+} else if ( d!=ampersand ) {
+ goto FINISH_PATH;
+}
+mp_get_x_next(mp);
+if ( mp->cur_cmd==left_brace ) {
+ @<Put the post-join direction information into |x| and |t|@>;
+} else if ( mp_right_type(q)!=mp_explicit ) {
+ t=mp_open; x=0;
+}
+
+@ The |scan_direction| subroutine looks at the directional information
+that is enclosed in braces, and also scans ahead to the following character.
+A type code is returned, either |open| (if the direction was $(0,0)$),
+or |curl| (if the direction was a curl of known value |cur_exp|), or
+|given| (if the direction is given by the |angle| value that now
+appears in |cur_exp|).
+
+There's nothing difficult about this subroutine, but the program is rather
+lengthy because a variety of potential errors need to be nipped in the bud.
+
+@c
+static quarterword mp_scan_direction (MP mp) {
+ int t; /* the type of information found */
+ scaled x; /* an |x| coordinate */
+ mp_get_x_next(mp);
+ if ( mp->cur_cmd==curl_command ) {
+ @<Scan a curl specification@>;
+ } else {
+ @<Scan a given direction@>;
+ }
+ if ( mp->cur_cmd!=right_brace ) {
+ mp_missing_err(mp, "}");
+@.Missing `\char`\}'@>
+ help3("I've scanned a direction spec for part of a path,",
+ "so a right brace should have come next.",
+ "I shall pretend that one was there.");
+ mp_back_error(mp);
+ }
+ mp_get_x_next(mp);
+ return t;
+}
+
+@ @<Scan a curl specification@>=
+{ mp_get_x_next(mp); mp_scan_expression(mp);
+if ( (mp->cur_type!=mp_known)||(mp->cur_exp<0) ){
+ exp_err("Improper curl has been replaced by 1");
+@.Improper curl@>
+ help1("A curl must be a known, nonnegative number.");
+ mp_put_get_flush_error(mp, unity);
+}
+t=mp_curl;
+}
+
+@ @<Scan a given direction@>=
+{ mp_scan_expression(mp);
+ if ( mp->cur_type>mp_pair_type ) {
+ @<Get given directions separated by commas@>;
+ } else {
+ mp_known_pair(mp);
+ }
+ if ( (mp->cur_x==0)&&(mp->cur_y==0) ) t=mp_open;
+ else { t=mp_given; mp->cur_exp=mp_n_arg(mp, mp->cur_x,mp->cur_y);}
+}
+
+@ @<Get given directions separated by commas@>=
+{
+ if ( mp->cur_type!=mp_known ) {
+ exp_err("Undefined x coordinate has been replaced by 0");
+@.Undefined coordinates...@>
+ help5("I need a `known' x value for this part of the path.",
+ "The value I found (see above) was no good;",
+ "so I'll try to keep going by using zero instead.",
+ "(Chapter 27 of The METAFONTbook explains that",
+@:METAFONTbook}{\sl The {\logos METAFONT\/}book@>
+ "you might want to type `I ??" "?' now.)");
+ mp_put_get_flush_error(mp, 0);
+ }
+ x=mp->cur_exp;
+ if ( mp->cur_cmd!=comma ) {
+ mp_missing_err(mp, ",");
+@.Missing `,'@>
+ help2("I've got the x coordinate of a path direction;",
+ "will look for the y coordinate next.");
+ mp_back_error(mp);
+ }
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_known ) {
+ exp_err("Undefined y coordinate has been replaced by 0");
+ help5("I need a `known' y value for this part of the path.",
+ "The value I found (see above) was no good;",
+ "so I'll try to keep going by using zero instead.",
+ "(Chapter 27 of The METAFONTbook explains that",
+ "you might want to type `I ??" "?' now.)");
+ mp_put_get_flush_error(mp, 0);
+ }
+ mp->cur_y=mp->cur_exp; mp->cur_x=x;
+}
+
+@ At this point |mp_right_type(q)| is usually |open|, but it may have been
+set to some other value by a previous operation. We must maintain
+the value of |mp_right_type(q)| in cases such as
+`\.{..\{curl2\}z\{0,0\}..}'.
+
+@<Put the pre-join...@>=
+{
+ t=mp_scan_direction(mp);
+ if ( t!=mp_open ) {
+ mp_right_type(q)=t; right_given(q)=mp->cur_exp;
+ if ( mp_left_type(q)==mp_open ) {
+ mp_left_type(q)=t; left_given(q)=mp->cur_exp;
+ } /* note that |left_given(q)=left_curl(q)| */
+ }
+}
+
+@ Since |left_tension| and |mp_left_y| share the same position in knot nodes,
+and since |left_given| is similarly equivalent to |mp_left_x|, we use
+|x| and |y| to hold the given direction and tension information when
+there are no explicit control points.
+
+@<Put the post-join...@>=
+{
+ t=mp_scan_direction(mp);
+ if ( mp_right_type(q)!=mp_explicit ) x=mp->cur_exp;
+ else t=mp_explicit; /* the direction information is superfluous */
+}
+
+@ @<Determine the tension and/or...@>=
+{
+ mp_get_x_next(mp);
+ if ( mp->cur_cmd==tension ) {
+ @<Set explicit tensions@>;
+ } else if ( mp->cur_cmd==controls ) {
+ @<Set explicit control points@>;
+ } else {
+ right_tension(q)=unity; y=unity; mp_back_input(mp); /* default tension */
+ goto DONE;
+ };
+ if ( mp->cur_cmd!=path_join ) {
+ mp_missing_err(mp, "..");
+@.Missing `..'@>
+ help1("A path join command should end with two dots.");
+ mp_back_error(mp);
+ }
+DONE:
+ ;
+}
+
+@ @<Set explicit tensions@>=
+{
+ mp_get_x_next(mp); y=mp->cur_cmd;
+ if ( mp->cur_cmd==at_least ) mp_get_x_next(mp);
+ mp_scan_primary(mp);
+ @<Make sure that the current expression is a valid tension setting@>;
+ if ( y==at_least ) negate(mp->cur_exp);
+ right_tension(q)=mp->cur_exp;
+ if ( mp->cur_cmd==and_command ) {
+ mp_get_x_next(mp); y=mp->cur_cmd;
+ if ( mp->cur_cmd==at_least ) mp_get_x_next(mp);
+ mp_scan_primary(mp);
+ @<Make sure that the current expression is a valid tension setting@>;
+ if ( y==at_least ) negate(mp->cur_exp);
+ }
+ y=mp->cur_exp;
+}
+
+@ @d min_tension three_quarter_unit
+
+@<Make sure that the current expression is a valid tension setting@>=
+if ( (mp->cur_type!=mp_known)||(mp->cur_exp<min_tension) ) {
+ exp_err("Improper tension has been set to 1");
+@.Improper tension@>
+ help1("The expression above should have been a number >=3/4.");
+ mp_put_get_flush_error(mp, unity);
+}
+
+@ @<Set explicit control points@>=
+{
+ mp_right_type(q)=mp_explicit; t=mp_explicit; mp_get_x_next(mp); mp_scan_primary(mp);
+ mp_known_pair(mp); mp_right_x(q)=mp->cur_x; mp_right_y(q)=mp->cur_y;
+ if ( mp->cur_cmd!=and_command ) {
+ x=mp_right_x(q); y=mp_right_y(q);
+ } else {
+ mp_get_x_next(mp); mp_scan_primary(mp);
+ mp_known_pair(mp); x=mp->cur_x; y=mp->cur_y;
+ }
+}
+
+@ @<Convert the right operand, |cur_exp|, into a partial path...@>=
+{
+ if ( mp->cur_type!=mp_path_type ) pp=mp_new_knot(mp);
+ else pp=mp->cur_exp;
+ qq=pp;
+ while ( mp_link(qq)!=pp ) qq=mp_link(qq);
+ if ( mp_left_type(pp)!=mp_endpoint ) { /* open up a cycle */
+ r=mp_copy_knot(mp, pp); mp_link(qq)=r; qq=r;
+ }
+ mp_left_type(pp)=mp_open; mp_right_type(qq)=mp_open;
+}
+
+@ If a person tries to define an entire path by saying `\.{(x,y)\&cycle}',
+we silently change the specification to `\.{(x,y)..cycle}', since a cycle
+shouldn't have length zero.
+
+@<Get ready to close a cycle@>=
+{
+ cycle_hit=true; mp_get_x_next(mp); pp=p; qq=p;
+ if ( d==ampersand ) if ( p==q ) {
+ d=path_join; right_tension(q)=unity; y=unity;
+ }
+}
+
+@ @<Join the partial paths and reset |p| and |q|...@>=
+{
+if ( d==ampersand ) {
+ if ( (mp_x_coord(q)!=mp_x_coord(pp))||(mp_y_coord(q)!=mp_y_coord(pp)) ) {
+ print_err("Paths don't touch; `&' will be changed to `..'");
+@.Paths don't touch@>
+ help3("When you join paths `p&q', the ending point of p",
+ "must be exactly equal to the starting point of q.",
+ "So I'm going to pretend that you said `p..q' instead.");
+ mp_put_get_error(mp); d=path_join; right_tension(q)=unity; y=unity;
+ }
+}
+@<Plug an opening in |mp_right_type(pp)|, if possible@>;
+if ( d==ampersand ) {
+ @<Splice independent paths together@>;
+} else {
+ @<Plug an opening in |mp_right_type(q)|, if possible@>;
+ mp_link(q)=pp; mp_left_y(pp)=y;
+ if ( t!=mp_open ) { mp_left_x(pp)=x; mp_left_type(pp)=t; };
+}
+q=qq;
+}
+
+@ @<Plug an opening in |mp_right_type(q)|...@>=
+if ( mp_right_type(q)==mp_open ) {
+ if ( (mp_left_type(q)==mp_curl)||(mp_left_type(q)==mp_given) ) {
+ mp_right_type(q)=mp_left_type(q); right_given(q)=left_given(q);
+ }
+}
+
+@ @<Plug an opening in |mp_right_type(pp)|...@>=
+if ( mp_right_type(pp)==mp_open ) {
+ if ( (t==mp_curl)||(t==mp_given) ) {
+ mp_right_type(pp)=t; right_given(pp)=x;
+ }
+}
+
+@ @<Splice independent paths together@>=
+{
+ if ( mp_left_type(q)==mp_open ) if ( mp_right_type(q)==mp_open ) {
+ mp_left_type(q)=mp_curl; left_curl(q)=unity;
+ }
+ if ( mp_right_type(pp)==mp_open ) if ( t==mp_open ) {
+ mp_right_type(pp)=mp_curl; right_curl(pp)=unity;
+ }
+ mp_right_type(q)=mp_right_type(pp); mp_link(q)=mp_link(pp);
+ mp_right_x(q)=mp_right_x(pp); mp_right_y(q)=mp_right_y(pp);
+ mp_free_node(mp, pp,knot_node_size);
+ if ( qq==pp ) qq=q;
+}
+
+@ @<Choose control points for the path...@>=
+if ( cycle_hit ) {
+ if ( d==ampersand ) p=q;
+} else {
+ mp_left_type(p)=mp_endpoint;
+ if ( mp_right_type(p)==mp_open ) {
+ mp_right_type(p)=mp_curl; right_curl(p)=unity;
+ }
+ mp_right_type(q)=mp_endpoint;
+ if ( mp_left_type(q)==mp_open ) {
+ mp_left_type(q)=mp_curl; left_curl(q)=unity;
+ }
+ mp_link(q)=p;
+}
+mp_make_choices(mp, p);
+mp->cur_type=mp_path_type; mp->cur_exp=p
+
+@ Finally, we sometimes need to scan an expression whose value is
+supposed to be either |true_code| or |false_code|.
+
+@<Declare the basic parsing subroutines@>=
+static void mp_get_boolean (MP mp) {
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_boolean_type ) {
+ exp_err("Undefined condition will be treated as `false'");
+@.Undefined condition...@>
+ help2("The expression shown above should have had a definite",
+ "true-or-false value. I'm changing it to `false'.");
+ mp_put_get_flush_error(mp, false_code); mp->cur_type=mp_boolean_type;
+ }
+}
+
+@* \[39] Doing the operations.
+The purpose of parsing is primarily to permit people to avoid piles of
+parentheses. But the real work is done after the structure of an expression
+has been recognized; that's when new expressions are generated. We
+turn now to the guts of \MP, which handles individual operators that
+have come through the parsing mechanism.
+
+We'll start with the easy ones that take no operands, then work our way
+up to operators with one and ultimately two arguments. In other words,
+we will write the three procedures |do_nullary|, |do_unary|, and |do_binary|
+that are invoked periodically by the expression scanners.
+
+First let's make sure that all of the primitive operators are in the
+hash table. Although |scan_primary| and its relatives made use of the
+\\{cmd} code for these operators, the \\{do} routines base everything
+on the \\{mod} code. For example, |do_binary| doesn't care whether the
+operation it performs is a |primary_binary| or |secondary_binary|, etc.
+
+@<Put each...@>=
+mp_primitive(mp, "true",nullary,true_code);
+@:true_}{\&{true} primitive@>
+mp_primitive(mp, "false",nullary,false_code);
+@:false_}{\&{false} primitive@>
+mp_primitive(mp, "nullpicture",nullary,null_picture_code);
+@:null_picture_}{\&{nullpicture} primitive@>
+mp_primitive(mp, "nullpen",nullary,null_pen_code);
+@:null_pen_}{\&{nullpen} primitive@>
+mp_primitive(mp, "jobname",nullary,job_name_op);
+@:job_name_}{\&{jobname} primitive@>
+mp_primitive(mp, "readstring",nullary,read_string_op);
+@:read_string_}{\&{readstring} primitive@>
+mp_primitive(mp, "pencircle",nullary,pen_circle);
+@:pen_circle_}{\&{pencircle} primitive@>
+mp_primitive(mp, "normaldeviate",nullary,normal_deviate);
+@:normal_deviate_}{\&{normaldeviate} primitive@>
+mp_primitive(mp, "readfrom",unary,read_from_op);
+@:read_from_}{\&{readfrom} primitive@>
+mp_primitive(mp, "closefrom",unary,close_from_op);
+@:close_from_}{\&{closefrom} primitive@>
+mp_primitive(mp, "odd",unary,odd_op);
+@:odd_}{\&{odd} primitive@>
+mp_primitive(mp, "known",unary,known_op);
+@:known_}{\&{known} primitive@>
+mp_primitive(mp, "unknown",unary,unknown_op);
+@:unknown_}{\&{unknown} primitive@>
+mp_primitive(mp, "not",unary,not_op);
+@:not_}{\&{not} primitive@>
+mp_primitive(mp, "decimal",unary,decimal);
+@:decimal_}{\&{decimal} primitive@>
+mp_primitive(mp, "reverse",unary,reverse);
+@:reverse_}{\&{reverse} primitive@>
+mp_primitive(mp, "makepath",unary,make_path_op);
+@:make_path_}{\&{makepath} primitive@>
+mp_primitive(mp, "makepen",unary,make_pen_op);
+@:make_pen_}{\&{makepen} primitive@>
+mp_primitive(mp, "oct",unary,oct_op);
+@:oct_}{\&{oct} primitive@>
+mp_primitive(mp, "hex",unary,hex_op);
+@:hex_}{\&{hex} primitive@>
+mp_primitive(mp, "ASCII",unary,ASCII_op);
+@:ASCII_}{\&{ASCII} primitive@>
+mp_primitive(mp, "char",unary,char_op);
+@:char_}{\&{char} primitive@>
+mp_primitive(mp, "length",unary,length_op);
+@:length_}{\&{length} primitive@>
+mp_primitive(mp, "turningnumber",unary,turning_op);
+@:turning_number_}{\&{turningnumber} primitive@>
+mp_primitive(mp, "xpart",unary,x_part);
+@:x_part_}{\&{xpart} primitive@>
+mp_primitive(mp, "ypart",unary,y_part);
+@:y_part_}{\&{ypart} primitive@>
+mp_primitive(mp, "xxpart",unary,xx_part);
+@:xx_part_}{\&{xxpart} primitive@>
+mp_primitive(mp, "xypart",unary,xy_part);
+@:xy_part_}{\&{xypart} primitive@>
+mp_primitive(mp, "yxpart",unary,yx_part);
+@:yx_part_}{\&{yxpart} primitive@>
+mp_primitive(mp, "yypart",unary,yy_part);
+@:yy_part_}{\&{yypart} primitive@>
+mp_primitive(mp, "redpart",unary,red_part);
+@:red_part_}{\&{redpart} primitive@>
+mp_primitive(mp, "greenpart",unary,green_part);
+@:green_part_}{\&{greenpart} primitive@>
+mp_primitive(mp, "bluepart",unary,blue_part);
+@:blue_part_}{\&{bluepart} primitive@>
+mp_primitive(mp, "cyanpart",unary,cyan_part);
+@:cyan_part_}{\&{cyanpart} primitive@>
+mp_primitive(mp, "magentapart",unary,magenta_part);
+@:magenta_part_}{\&{magentapart} primitive@>
+mp_primitive(mp, "yellowpart",unary,yellow_part);
+@:yellow_part_}{\&{yellowpart} primitive@>
+mp_primitive(mp, "blackpart",unary,black_part);
+@:black_part_}{\&{blackpart} primitive@>
+mp_primitive(mp, "greypart",unary,grey_part);
+@:grey_part_}{\&{greypart} primitive@>
+mp_primitive(mp, "colormodel",unary,color_model_part);
+@:color_model_part_}{\&{colormodel} primitive@>
+mp_primitive(mp, "fontpart",unary,font_part);
+@:font_part_}{\&{fontpart} primitive@>
+mp_primitive(mp, "textpart",unary,text_part);
+@:text_part_}{\&{textpart} primitive@>
+mp_primitive(mp, "pathpart",unary,path_part);
+@:path_part_}{\&{pathpart} primitive@>
+mp_primitive(mp, "penpart",unary,pen_part);
+@:pen_part_}{\&{penpart} primitive@>
+mp_primitive(mp, "dashpart",unary,dash_part);
+@:dash_part_}{\&{dashpart} primitive@>
+mp_primitive(mp, "sqrt",unary,sqrt_op);
+@:sqrt_}{\&{sqrt} primitive@>
+mp_primitive(mp, "mexp",unary,mp_m_exp_op);
+@:m_exp_}{\&{mexp} primitive@>
+mp_primitive(mp, "mlog",unary,mp_m_log_op);
+@:m_log_}{\&{mlog} primitive@>
+mp_primitive(mp, "sind",unary,sin_d_op);
+@:sin_d_}{\&{sind} primitive@>
+mp_primitive(mp, "cosd",unary,cos_d_op);
+@:cos_d_}{\&{cosd} primitive@>
+mp_primitive(mp, "floor",unary,floor_op);
+@:floor_}{\&{floor} primitive@>
+mp_primitive(mp, "uniformdeviate",unary,uniform_deviate);
+@:uniform_deviate_}{\&{uniformdeviate} primitive@>
+mp_primitive(mp, "charexists",unary,char_exists_op);
+@:char_exists_}{\&{charexists} primitive@>
+mp_primitive(mp, "fontsize",unary,font_size);
+@:font_size_}{\&{fontsize} primitive@>
+mp_primitive(mp, "llcorner",unary,ll_corner_op);
+@:ll_corner_}{\&{llcorner} primitive@>
+mp_primitive(mp, "lrcorner",unary,lr_corner_op);
+@:lr_corner_}{\&{lrcorner} primitive@>
+mp_primitive(mp, "ulcorner",unary,ul_corner_op);
+@:ul_corner_}{\&{ulcorner} primitive@>
+mp_primitive(mp, "urcorner",unary,ur_corner_op);
+@:ur_corner_}{\&{urcorner} primitive@>
+mp_primitive(mp, "arclength",unary,arc_length);
+@:arc_length_}{\&{arclength} primitive@>
+mp_primitive(mp, "angle",unary,angle_op);
+@:angle_}{\&{angle} primitive@>
+mp_primitive(mp, "cycle",cycle,cycle_op);
+@:cycle_}{\&{cycle} primitive@>
+mp_primitive(mp, "stroked",unary,stroked_op);
+@:stroked_}{\&{stroked} primitive@>
+mp_primitive(mp, "filled",unary,filled_op);
+@:filled_}{\&{filled} primitive@>
+mp_primitive(mp, "textual",unary,textual_op);
+@:textual_}{\&{textual} primitive@>
+mp_primitive(mp, "clipped",unary,clipped_op);
+@:clipped_}{\&{clipped} primitive@>
+mp_primitive(mp, "bounded",unary,bounded_op);
+@:bounded_}{\&{bounded} primitive@>
+mp_primitive(mp, "+",plus_or_minus,plus);
+@:+ }{\.{+} primitive@>
+mp_primitive(mp, "-",plus_or_minus,minus);
+@:- }{\.{-} primitive@>
+mp_primitive(mp, "*",secondary_binary,times);
+@:* }{\.{*} primitive@>
+mp_primitive(mp, "/",slash,over); mp->eqtb[frozen_slash]=mp->eqtb[mp->cur_sym];
+@:/ }{\.{/} primitive@>
+mp_primitive(mp, "++",tertiary_binary,pythag_add);
+@:++_}{\.{++} primitive@>
+mp_primitive(mp, "+-+",tertiary_binary,pythag_sub);
+@:+-+_}{\.{+-+} primitive@>
+mp_primitive(mp, "or",tertiary_binary,or_op);
+@:or_}{\&{or} primitive@>
+mp_primitive(mp, "and",and_command,and_op);
+@:and_}{\&{and} primitive@>
+mp_primitive(mp, "<",expression_binary,less_than);
+@:< }{\.{<} primitive@>
+mp_primitive(mp, "<=",expression_binary,less_or_equal);
+@:<=_}{\.{<=} primitive@>
+mp_primitive(mp, ">",expression_binary,greater_than);
+@:> }{\.{>} primitive@>
+mp_primitive(mp, ">=",expression_binary,greater_or_equal);
+@:>=_}{\.{>=} primitive@>
+mp_primitive(mp, "=",equals,equal_to);
+@:= }{\.{=} primitive@>
+mp_primitive(mp, "<>",expression_binary,unequal_to);
+@:<>_}{\.{<>} primitive@>
+mp_primitive(mp, "substring",primary_binary,substring_of);
+@:substring_}{\&{substring} primitive@>
+mp_primitive(mp, "subpath",primary_binary,subpath_of);
+@:subpath_}{\&{subpath} primitive@>
+mp_primitive(mp, "directiontime",primary_binary,direction_time_of);
+@:direction_time_}{\&{directiontime} primitive@>
+mp_primitive(mp, "point",primary_binary,point_of);
+@:point_}{\&{point} primitive@>
+mp_primitive(mp, "precontrol",primary_binary,precontrol_of);
+@:precontrol_}{\&{precontrol} primitive@>
+mp_primitive(mp, "postcontrol",primary_binary,postcontrol_of);
+@:postcontrol_}{\&{postcontrol} primitive@>
+mp_primitive(mp, "penoffset",primary_binary,pen_offset_of);
+@:pen_offset_}{\&{penoffset} primitive@>
+mp_primitive(mp, "arctime",primary_binary,arc_time_of);
+@:arc_time_of_}{\&{arctime} primitive@>
+mp_primitive(mp, "mpversion",nullary,mp_version);
+@:mp_verison_}{\&{mpversion} primitive@>
+mp_primitive(mp, "&",ampersand,concatenate);
+@:!!!}{\.{\&} primitive@>
+mp_primitive(mp, "rotated",secondary_binary,rotated_by);
+@:rotated_}{\&{rotated} primitive@>
+mp_primitive(mp, "slanted",secondary_binary,slanted_by);
+@:slanted_}{\&{slanted} primitive@>
+mp_primitive(mp, "scaled",secondary_binary,scaled_by);
+@:scaled_}{\&{scaled} primitive@>
+mp_primitive(mp, "shifted",secondary_binary,shifted_by);
+@:shifted_}{\&{shifted} primitive@>
+mp_primitive(mp, "transformed",secondary_binary,transformed_by);
+@:transformed_}{\&{transformed} primitive@>
+mp_primitive(mp, "xscaled",secondary_binary,x_scaled);
+@:x_scaled_}{\&{xscaled} primitive@>
+mp_primitive(mp, "yscaled",secondary_binary,y_scaled);
+@:y_scaled_}{\&{yscaled} primitive@>
+mp_primitive(mp, "zscaled",secondary_binary,z_scaled);
+@:z_scaled_}{\&{zscaled} primitive@>
+mp_primitive(mp, "infont",secondary_binary,in_font);
+@:in_font_}{\&{infont} primitive@>
+mp_primitive(mp, "intersectiontimes",tertiary_binary,intersect);
+@:intersection_times_}{\&{intersectiontimes} primitive@>
+mp_primitive(mp, "envelope",primary_binary,envelope_of);
+@:envelope_}{\&{envelope} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case nullary:
+case unary:
+case primary_binary:
+case secondary_binary:
+case tertiary_binary:
+case expression_binary:
+case cycle:
+case plus_or_minus:
+case slash:
+case ampersand:
+case equals:
+case and_command:
+ mp_print_op(mp, m);
+ break;
+
+@ OK, let's look at the simplest \\{do} procedure first.
+
+@c @<Declare nullary action procedure@>
+static void mp_do_nullary (MP mp,quarterword c) {
+ check_arith;
+ if ( mp->internal[mp_tracing_commands]>two )
+ mp_show_cmd_mod(mp, nullary,c);
+ switch (c) {
+ case true_code: case false_code:
+ mp->cur_type=mp_boolean_type; mp->cur_exp=c;
+ break;
+ case null_picture_code:
+ mp->cur_type=mp_picture_type;
+ mp->cur_exp=mp_get_node(mp, edge_header_size);
+ mp_init_edges(mp, mp->cur_exp);
+ break;
+ case null_pen_code:
+ mp->cur_type=mp_pen_type; mp->cur_exp=mp_get_pen_circle(mp, 0);
+ break;
+ case normal_deviate:
+ mp->cur_type=mp_known; mp->cur_exp=mp_norm_rand(mp);
+ break;
+ case pen_circle:
+ mp->cur_type=mp_pen_type; mp->cur_exp=mp_get_pen_circle(mp, unity);
+ break;
+ case job_name_op:
+ if ( mp->job_name==NULL ) mp_open_log_file(mp);
+ mp->cur_type=mp_string_type; mp->cur_exp=rts(mp->job_name);
+ break;
+ case mp_version:
+ mp->cur_type=mp_string_type;
+ mp->cur_exp=intern(metapost_version) ;
+ break;
+ case read_string_op:
+ @<Read a string from the terminal@>;
+ break;
+ } /* there are no other cases */
+ check_arith;
+}
+
+@ @<Read a string...@>=
+{
+ if (mp->noninteractive || mp->interaction<=mp_nonstop_mode )
+ mp_fatal_error(mp, "*** (cannot readstring in nonstop modes)");
+ mp_begin_file_reading(mp); name=is_read;
+ limit=start; prompt_input("");
+ mp_finish_read(mp);
+}
+
+@ @<Declare nullary action procedure@>=
+static void mp_finish_read (MP mp) { /* copy |buffer| line to |cur_exp| */
+ size_t k;
+ str_room((int)mp->last-start);
+ for (k=(size_t)start;k<mp->last;k++) {
+ append_char(mp->buffer[k]);
+ }
+ mp_end_file_reading(mp); mp->cur_type=mp_string_type;
+ mp->cur_exp=mp_make_string(mp);
+}
+
+@ Things get a bit more interesting when there's an operand. The
+operand to |do_unary| appears in |cur_type| and |cur_exp|.
+
+@c @<Declare unary action procedures@>
+static void mp_do_unary (MP mp,quarterword c) {
+ pointer p,q,r; /* for list manipulation */
+ integer x; /* a temporary register */
+ check_arith;
+ if ( mp->internal[mp_tracing_commands]>two )
+ @<Trace the current unary operation@>;
+ switch (c) {
+ case plus:
+ if ( mp->cur_type<mp_color_type ) mp_bad_unary(mp, plus);
+ break;
+ case minus:
+ @<Negate the current expression@>;
+ break;
+ @<Additional cases of unary operators@>;
+ } /* there are no other cases */
+ check_arith;
+}
+
+@ The |nice_pair| function returns |true| if both components of a pair
+are known.
+
+@<Declare unary action procedures@>=
+static boolean mp_nice_pair (MP mp,integer p, quarterword t) {
+ if ( t==mp_pair_type ) {
+ p=value(p);
+ if ( mp_type(x_part_loc(p))==mp_known )
+ if ( mp_type(y_part_loc(p))==mp_known )
+ return true;
+ }
+ return false;
+}
+
+@ The |nice_color_or_pair| function is analogous except that it also accepts
+fully known colors.
+
+@<Declare unary action procedures@>=
+static boolean mp_nice_color_or_pair (MP mp,integer p, quarterword t) {
+ pointer q,r; /* for scanning the big node */
+ if ( (t!=mp_pair_type)&&(t!=mp_color_type)&&(t!=mp_cmykcolor_type) ) {
+ return false;
+ } else {
+ q=value(p);
+ r=q+mp->big_node_size[mp_type(p)];
+ do {
+ r=r-2;
+ if ( mp_type(r)!=mp_known )
+ return false;
+ } while (r!=q);
+ return true;
+ }
+}
+
+@ @<Declare unary action...@>=
+static void mp_print_known_or_unknown_type (MP mp,quarterword t, integer v) {
+ mp_print_char(mp, xord('('));
+ if ( t>mp_known ) mp_print(mp, "unknown numeric");
+ else { if ( (t==mp_pair_type)||(t==mp_color_type)||(t==mp_cmykcolor_type) )
+ if ( ! mp_nice_color_or_pair(mp, v,t) ) mp_print(mp, "unknown ");
+ mp_print_type(mp, t);
+ }
+ mp_print_char(mp, xord(')'));
+}
+
+@ @<Declare unary action...@>=
+static void mp_bad_unary (MP mp,quarterword c) {
+ exp_err("Not implemented: "); mp_print_op(mp, c);
+@.Not implemented...@>
+ mp_print_known_or_unknown_type(mp, mp->cur_type,mp->cur_exp);
+ help3("I'm afraid I don't know how to apply that operation to that",
+ "particular type. Continue, and I'll simply return the",
+ "argument (shown above) as the result of the operation.");
+ mp_put_get_error(mp);
+}
+
+@ @<Trace the current unary operation@>=
+{
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "{");
+ mp_print_op(mp, c); mp_print_char(mp, xord('('));
+ mp_print_exp(mp, null,0); /* show the operand, but not verbosely */
+ mp_print(mp, ")}"); mp_end_diagnostic(mp, false);
+}
+
+@ Negation is easy except when the current expression
+is of type |independent|, or when it is a pair with one or more
+|independent| components.
+
+It is tempting to argue that the negative of an independent variable
+is an independent variable, hence we don't have to do anything when
+negating it. The fallacy is that other dependent variables pointing
+to the current expression must change the sign of their
+coefficients if we make no change to the current expression.
+
+Instead, we work around the problem by copying the current expression
+and recycling it afterwards (cf.~the |stash_in| routine).
+
+@<Negate the current expression@>=
+switch (mp->cur_type) {
+case mp_color_type:
+case mp_cmykcolor_type:
+case mp_pair_type:
+case mp_independent:
+ q=mp->cur_exp; mp_make_exp_copy(mp, q);
+ if ( mp->cur_type==mp_dependent ) {
+ mp_negate_dep_list(mp, dep_list(mp->cur_exp));
+ } else if ( mp->cur_type<=mp_pair_type ) { /* |mp_color_type| or |mp_pair_type| */
+ p=value(mp->cur_exp);
+ r=p+mp->big_node_size[mp->cur_type];
+ do {
+ r=r-2;
+ if ( mp_type(r)==mp_known ) negate(value(r));
+ else mp_negate_dep_list(mp, dep_list(r));
+ } while (r!=p);
+ } /* if |cur_type=mp_known| then |cur_exp=0| */
+ mp_recycle_value(mp, q); mp_free_node(mp, q,value_node_size);
+ break;
+case mp_dependent:
+case mp_proto_dependent:
+ mp_negate_dep_list(mp, dep_list(mp->cur_exp));
+ break;
+case mp_known:
+ negate(mp->cur_exp);
+ break;
+default:
+ mp_bad_unary(mp, minus);
+ break;
+}
+
+@ @<Declare unary action...@>=
+static void mp_negate_dep_list (MP mp,pointer p) {
+ while (1) {
+ negate(value(p));
+ if ( mp_info(p)==null ) return;
+ p=mp_link(p);
+ }
+}
+
+@ @<Additional cases of unary operators@>=
+case not_op:
+ if ( mp->cur_type!=mp_boolean_type ) mp_bad_unary(mp, not_op);
+ else mp->cur_exp=true_code+false_code-mp->cur_exp;
+ break;
+
+@ @d three_sixty_units 23592960 /* that's |360*unity| */
+@d boolean_reset(A) if ( (A) ) mp->cur_exp=true_code; else mp->cur_exp=false_code
+
+@<Additional cases of unary operators@>=
+case sqrt_op:
+case mp_m_exp_op:
+case mp_m_log_op:
+case sin_d_op:
+case cos_d_op:
+case floor_op:
+case uniform_deviate:
+case odd_op:
+case char_exists_op:
+ if ( mp->cur_type!=mp_known ) {
+ mp_bad_unary(mp, c);
+ } else {
+ switch (c) {
+ case sqrt_op:mp->cur_exp=mp_square_rt(mp, mp->cur_exp);break;
+ case mp_m_exp_op:mp->cur_exp=mp_m_exp(mp, mp->cur_exp);break;
+ case mp_m_log_op:mp->cur_exp=mp_m_log(mp, mp->cur_exp);break;
+ case sin_d_op:
+ case cos_d_op:
+ mp_n_sin_cos(mp, (mp->cur_exp % three_sixty_units)*16);
+ if ( c==sin_d_op ) mp->cur_exp=mp_round_fraction(mp, mp->n_sin);
+ else mp->cur_exp=mp_round_fraction(mp, mp->n_cos);
+ break;
+ case floor_op:mp->cur_exp=mp_floor_scaled(mp, mp->cur_exp);break;
+ case uniform_deviate:mp->cur_exp=mp_unif_rand(mp, mp->cur_exp);break;
+ case odd_op:
+ boolean_reset(odd(mp_round_unscaled(mp, mp->cur_exp)));
+ mp->cur_type=mp_boolean_type;
+ break;
+ case char_exists_op:
+ @<Determine if a character has been shipped out@>;
+ break;
+ } /* there are no other cases */
+ }
+ break;
+
+@ @<Additional cases of unary operators@>=
+case angle_op:
+ if ( mp_nice_pair(mp, mp->cur_exp,mp->cur_type) ) {
+ p=value(mp->cur_exp);
+ x=mp_n_arg(mp, value(x_part_loc(p)),value(y_part_loc(p)));
+ if ( x>=0 ) mp_flush_cur_exp(mp, (x+8)/ 16);
+ else mp_flush_cur_exp(mp, -((-x+8)/ 16));
+ } else {
+ mp_bad_unary(mp, angle_op);
+ }
+ break;
+
+@ If the current expression is a pair, but the context wants it to
+be a path, we call |pair_to_path|.
+
+@<Declare unary action...@>=
+static void mp_pair_to_path (MP mp) {
+ mp->cur_exp=mp_new_knot(mp);
+ mp->cur_type=mp_path_type;
+}
+
+@
+@d pict_color_type(A) ((mp_link(dummy_loc(mp->cur_exp))!=null) &&
+ (has_color(mp_link(dummy_loc(mp->cur_exp)))) &&
+ ((mp_color_model(mp_link(dummy_loc(mp->cur_exp)))==A)
+ ||
+ ((mp_color_model(mp_link(dummy_loc(mp->cur_exp)))==mp_uninitialized_model) &&
+ (mp->internal[mp_default_color_model]/unity)==(A))))
+
+@<Additional cases of unary operators@>=
+case x_part:
+case y_part:
+ if ( (mp->cur_type==mp_pair_type)||(mp->cur_type==mp_transform_type) )
+ mp_take_part(mp, c);
+ else if ( mp->cur_type==mp_picture_type ) mp_take_pict_part(mp, c);
+ else mp_bad_unary(mp, c);
+ break;
+case xx_part:
+case xy_part:
+case yx_part:
+case yy_part:
+ if ( mp->cur_type==mp_transform_type ) mp_take_part(mp, c);
+ else if ( mp->cur_type==mp_picture_type ) mp_take_pict_part(mp, c);
+ else mp_bad_unary(mp, c);
+ break;
+case red_part:
+case green_part:
+case blue_part:
+ if ( mp->cur_type==mp_color_type ) mp_take_part(mp, c);
+ else if ( mp->cur_type==mp_picture_type ) {
+ if pict_color_type(mp_rgb_model) mp_take_pict_part(mp, c);
+ else mp_bad_color_part(mp, c);
+ }
+ else mp_bad_unary(mp, c);
+ break;
+case cyan_part:
+case magenta_part:
+case yellow_part:
+case black_part:
+ if ( mp->cur_type==mp_cmykcolor_type) mp_take_part(mp, c);
+ else if ( mp->cur_type==mp_picture_type ) {
+ if pict_color_type(mp_cmyk_model) mp_take_pict_part(mp, c);
+ else mp_bad_color_part(mp, c);
+ }
+ else mp_bad_unary(mp, c);
+ break;
+case grey_part:
+ if ( mp->cur_type==mp_known ) mp->cur_exp=value(c);
+ else if ( mp->cur_type==mp_picture_type ) {
+ if pict_color_type(mp_grey_model) mp_take_pict_part(mp, c);
+ else mp_bad_color_part(mp, c);
+ }
+ else mp_bad_unary(mp, c);
+ break;
+case color_model_part:
+ if ( mp->cur_type==mp_picture_type ) mp_take_pict_part(mp, c);
+ else mp_bad_unary(mp, c);
+ break;
+
+@ @<Declarations@>=
+static void mp_bad_color_part(MP mp, quarterword c);
+
+@ @c
+static void mp_bad_color_part(MP mp, quarterword c) {
+ pointer p; /* the big node */
+ p=mp_link(dummy_loc(mp->cur_exp));
+ exp_err("Wrong picture color model: "); mp_print_op(mp, c);
+@.Wrong picture color model...@>
+ if (mp_color_model(p)==mp_grey_model)
+ mp_print(mp, " of grey object");
+ else if (mp_color_model(p)==mp_cmyk_model)
+ mp_print(mp, " of cmyk object");
+ else if (mp_color_model(p)==mp_rgb_model)
+ mp_print(mp, " of rgb object");
+ else if (mp_color_model(p)==mp_no_model)
+ mp_print(mp, " of marking object");
+ else
+ mp_print(mp," of defaulted object");
+ help3("You can only ask for the redpart, greenpart, bluepart of a rgb object,",
+ "the cyanpart, magentapart, yellowpart or blackpart of a cmyk object, ",
+ "or the greypart of a grey object. No mixing and matching, please.");
+ mp_error(mp);
+ if (c==black_part)
+ mp_flush_cur_exp(mp,unity);
+ else
+ mp_flush_cur_exp(mp,0);
+}
+
+@ In the following procedure, |cur_exp| points to a capsule, which points to
+a big node. We want to delete all but one part of the big node.
+
+@<Declare unary action...@>=
+static void mp_take_part (MP mp,quarterword c) {
+ pointer p; /* the big node */
+ p=value(mp->cur_exp); value(temp_val)=p; mp_type(temp_val)=mp->cur_type;
+ mp_link(p)=temp_val; mp_free_node(mp, mp->cur_exp,value_node_size);
+ mp_make_exp_copy(mp, p+mp->sector_offset[c+mp_x_part_sector-x_part]);
+ mp_recycle_value(mp, temp_val);
+}
+
+@ @<Initialize table entries...@>=
+mp_name_type(temp_val)=mp_capsule;
+
+@ @<Additional cases of unary operators@>=
+case font_part:
+case text_part:
+case path_part:
+case pen_part:
+case dash_part:
+ if ( mp->cur_type==mp_picture_type ) mp_take_pict_part(mp, c);
+ else mp_bad_unary(mp, c);
+ break;
+
+@ @<Declarations@>=
+static void mp_scale_edges (MP mp);
+
+@ @<Declare unary action...@>=
+static void mp_take_pict_part (MP mp,quarterword c) {
+ pointer p; /* first graphical object in |cur_exp| */
+ p=mp_link(dummy_loc(mp->cur_exp));
+ if ( p!=null ) {
+ switch (c) {
+ case x_part: case y_part: case xx_part:
+ case xy_part: case yx_part: case yy_part:
+ if ( mp_type(p)==mp_text_code ) mp_flush_cur_exp(mp, text_trans_part(p+c));
+ else goto NOT_FOUND;
+ break;
+ case red_part: case green_part: case blue_part:
+ if ( has_color(p) ) mp_flush_cur_exp(mp, obj_color_part(p+c));
+ else goto NOT_FOUND;
+ break;
+ case cyan_part: case magenta_part: case yellow_part:
+ case black_part:
+ if ( has_color(p) ) {
+ if ( mp_color_model(p)==mp_uninitialized_model && c==black_part)
+ mp_flush_cur_exp(mp, unity);
+ else
+ mp_flush_cur_exp(mp, obj_color_part(p+c+(red_part-cyan_part)));
+ } else goto NOT_FOUND;
+ break;
+ case grey_part:
+ if ( has_color(p) )
+ mp_flush_cur_exp(mp, obj_color_part(p+c+(red_part-grey_part)));
+ else goto NOT_FOUND;
+ break;
+ case color_model_part:
+ if ( has_color(p) ) {
+ if ( mp_color_model(p)==mp_uninitialized_model )
+ mp_flush_cur_exp(mp, mp->internal[mp_default_color_model]);
+ else
+ mp_flush_cur_exp(mp, mp_color_model(p)*unity);
+ } else goto NOT_FOUND;
+ break;
+ @<Handle other cases in |take_pict_part| or |goto not_found|@>;
+ } /* all cases have been enumerated */
+ return;
+ };
+NOT_FOUND:
+ @<Convert the current expression to a null value appropriate
+ for |c|@>;
+}
+
+@ @<Handle other cases in |take_pict_part| or |goto not_found|@>=
+case text_part:
+ if ( mp_type(p)!=mp_text_code ) goto NOT_FOUND;
+ else {
+ mp_flush_cur_exp(mp, mp_text_p(p));
+ add_str_ref(mp->cur_exp);
+ mp->cur_type=mp_string_type;
+ };
+ break;
+case font_part:
+ if ( mp_type(p)!=mp_text_code ) goto NOT_FOUND;
+ else {
+ mp_flush_cur_exp(mp, rts(mp->font_name[mp_font_n(p)]));
+ add_str_ref(mp->cur_exp);
+ mp->cur_type=mp_string_type;
+ };
+ break;
+case path_part:
+ if ( mp_type(p)==mp_text_code ) goto NOT_FOUND;
+ else if ( is_stop(p) ) mp_confusion(mp, "pict");
+@:this can't happen pict}{\quad pict@>
+ else {
+ mp_flush_cur_exp(mp, mp_copy_path(mp, mp_path_p(p)));
+ mp->cur_type=mp_path_type;
+ }
+ break;
+case pen_part:
+ if ( ! has_pen(p) ) goto NOT_FOUND;
+ else {
+ if ( mp_pen_p(p)==null ) goto NOT_FOUND;
+ else { mp_flush_cur_exp(mp, copy_pen(mp_pen_p(p)));
+ mp->cur_type=mp_pen_type;
+ };
+ }
+ break;
+case dash_part:
+ if ( mp_type(p)!=mp_stroked_code ) goto NOT_FOUND;
+ else { if ( mp_dash_p(p)==null ) goto NOT_FOUND;
+ else { add_edge_ref(mp_dash_p(p));
+ mp->se_sf=dash_scale(p);
+ mp->se_pic=mp_dash_p(p);
+ mp_scale_edges(mp);
+ mp_flush_cur_exp(mp, mp->se_pic);
+ mp->cur_type=mp_picture_type;
+ };
+ }
+ break;
+
+@ Since |scale_edges| had to be declared |forward|, it had to be declared as a
+parameterless procedure even though it really takes two arguments and updates
+one of them. Hence the following globals are needed.
+
+@<Global...@>=
+pointer se_pic; /* edge header used and updated by |scale_edges| */
+scaled se_sf; /* the scale factor argument to |scale_edges| */
+
+@ @<Convert the current expression to a null value appropriate...@>=
+switch (c) {
+case text_part: case font_part:
+ mp_flush_cur_exp(mp, null_str);
+ mp->cur_type=mp_string_type;
+ break;
+case path_part:
+ mp_flush_cur_exp(mp, mp_get_node(mp, knot_node_size));
+ mp_left_type(mp->cur_exp)=mp_endpoint;
+ mp_right_type(mp->cur_exp)=mp_endpoint;
+ mp_link(mp->cur_exp)=mp->cur_exp;
+ mp_x_coord(mp->cur_exp)=0;
+ mp_y_coord(mp->cur_exp)=0;
+ mp_originator(mp->cur_exp)=mp_metapost_user;
+ mp->cur_type=mp_path_type;
+ break;
+case pen_part:
+ mp_flush_cur_exp(mp, mp_get_pen_circle(mp, 0));
+ mp->cur_type=mp_pen_type;
+ break;
+case dash_part:
+ mp_flush_cur_exp(mp, mp_get_node(mp, edge_header_size));
+ mp_init_edges(mp, mp->cur_exp);
+ mp->cur_type=mp_picture_type;
+ break;
+default:
+ mp_flush_cur_exp(mp, 0);
+ break;
+}
+
+@ @<Additional cases of unary...@>=
+case char_op:
+ if ( mp->cur_type!=mp_known ) {
+ mp_bad_unary(mp, char_op);
+ } else {
+ mp->cur_exp=mp_round_unscaled(mp, mp->cur_exp) % 256;
+ mp->cur_type=mp_string_type;
+ if ( mp->cur_exp<0 ) mp->cur_exp=mp->cur_exp+256;
+ }
+ break;
+case decimal:
+ if ( mp->cur_type!=mp_known ) {
+ mp_bad_unary(mp, decimal);
+ } else {
+ mp->old_setting=mp->selector; mp->selector=new_string;
+ mp_print_scaled(mp, mp->cur_exp); mp->cur_exp=mp_make_string(mp);
+ mp->selector=mp->old_setting; mp->cur_type=mp_string_type;
+ }
+ break;
+case oct_op:
+case hex_op:
+case ASCII_op:
+ if ( mp->cur_type!=mp_string_type ) mp_bad_unary(mp, c);
+ else mp_str_to_num(mp, c);
+ break;
+case font_size:
+ if ( mp->cur_type!=mp_string_type ) mp_bad_unary(mp, font_size);
+ else @<Find the design size of the font whose name is |cur_exp|@>;
+ break;
+
+@ @<Declare unary action...@>=
+static void mp_str_to_num (MP mp,quarterword c) { /* converts a string to a number */
+ integer n; /* accumulator */
+ ASCII_code m; /* current character */
+ pool_pointer k; /* index into |str_pool| */
+ int b; /* radix of conversion */
+ boolean bad_char; /* did the string contain an invalid digit? */
+ if ( c==ASCII_op ) {
+ if ( length(mp->cur_exp)==0 ) n=-1;
+ else n=mp->str_pool[mp->str_start[mp->cur_exp]];
+ } else {
+ if ( c==oct_op ) b=8; else b=16;
+ n=0; bad_char=false;
+ for (k=mp->str_start[mp->cur_exp];k<str_stop(mp->cur_exp);k++) {
+ m=mp->str_pool[k];
+ if ( (m>='0')&&(m<='9') ) m=m-'0';
+ else if ( (m>='A')&&(m<='F') ) m=m-'A'+10;
+ else if ( (m>='a')&&(m<='f') ) m=m-'a'+10;
+ else { bad_char=true; m=0; };
+ if ( (int)m>=b ) { bad_char=true; m=0; };
+ if ( n<32768 / b ) n=n*b+m; else n=32767;
+ }
+ @<Give error messages if |bad_char| or |n>=4096|@>;
+ }
+ mp_flush_cur_exp(mp, n*unity);
+}
+
+@ @<Give error messages if |bad_char|...@>=
+if ( bad_char ) {
+ exp_err("String contains illegal digits");
+@.String contains illegal digits@>
+ if ( c==oct_op ) {
+ help1("I zeroed out characters that weren't in the range 0..7.");
+ } else {
+ help1("I zeroed out characters that weren't hex digits.");
+ }
+ mp_put_get_error(mp);
+}
+if ( (n>4095) ) {
+ if ( mp->internal[mp_warning_check]>0 ) {
+ print_err("Number too large (");
+ mp_print_int(mp, n); mp_print_char(mp, xord(')'));
+@.Number too large@>
+ help2("I have trouble with numbers greater than 4095; watch out.",
+ "(Set warningcheck:=0 to suppress this message.)");
+ mp_put_get_error(mp);
+ }
+}
+
+@ The length operation is somewhat unusual in that it applies to a variety
+of different types of operands.
+
+@<Additional cases of unary...@>=
+case length_op:
+ switch (mp->cur_type) {
+ case mp_string_type: mp_flush_cur_exp(mp, length(mp->cur_exp)*unity); break;
+ case mp_path_type: mp_flush_cur_exp(mp, mp_path_length(mp)); break;
+ case mp_known: mp->cur_exp=abs(mp->cur_exp); break;
+ case mp_picture_type: mp_flush_cur_exp(mp, mp_pict_length(mp)); break;
+ default:
+ if ( mp_nice_pair(mp, mp->cur_exp,mp->cur_type) )
+ mp_flush_cur_exp(mp, mp_pyth_add(mp,
+ value(x_part_loc(value(mp->cur_exp))),
+ value(y_part_loc(value(mp->cur_exp)))));
+ else mp_bad_unary(mp, c);
+ break;
+ }
+ break;
+
+@ @<Declare unary action...@>=
+static scaled mp_path_length (MP mp) { /* computes the length of the current path */
+ scaled n; /* the path length so far */
+ pointer p; /* traverser */
+ p=mp->cur_exp;
+ if ( mp_left_type(p)==mp_endpoint ) n=-unity; else n=0;
+ do { p=mp_link(p); n=n+unity; } while (p!=mp->cur_exp);
+ return n;
+}
+
+@ @<Declare unary action...@>=
+static scaled mp_pict_length (MP mp) {
+ /* counts interior components in picture |cur_exp| */
+ scaled n; /* the count so far */
+ pointer p; /* traverser */
+ n=0;
+ p=mp_link(dummy_loc(mp->cur_exp));
+ if ( p!=null ) {
+ if ( is_start_or_stop(p) )
+ if ( mp_skip_1component(mp, p)==null ) p=mp_link(p);
+ while ( p!=null ) {
+ skip_component(p) return n;
+ n=n+unity;
+ }
+ }
+ return n;
+}
+
+@ Implement |turningnumber|
+
+@<Additional cases of unary...@>=
+case turning_op:
+ if ( mp->cur_type==mp_pair_type ) mp_flush_cur_exp(mp, 0);
+ else if ( mp->cur_type!=mp_path_type ) mp_bad_unary(mp, turning_op);
+ else if ( mp_left_type(mp->cur_exp)==mp_endpoint )
+ mp_flush_cur_exp(mp, 0); /* not a cyclic path */
+ else
+ mp_flush_cur_exp(mp, mp_turn_cycles_wrapper(mp, mp->cur_exp));
+ break;
+
+@ The function |an_angle| returns the value of the |angle| primitive, or $0$ if the
+argument is |origin|.
+
+@<Declare unary action...@>=
+static angle mp_an_angle (MP mp,scaled xpar, scaled ypar) {
+ if ( (! ((xpar==0) && (ypar==0))) )
+ return mp_n_arg(mp, xpar,ypar);
+ return 0;
+}
+
+
+@ The actual turning number is (for the moment) computed in a C function
+that receives eight integers corresponding to the four controlling points,
+and returns a single angle. Besides those, we have to account for discrete
+moves at the actual points.
+
+@d mp_floor(a) ((a)>=0 ? (int)(a) : -(int)(-(a)))
+@d bezier_error (720*(256*256*16))+1
+@d mp_sign(v) ((v)>0 ? 1 : ((v)<0 ? -1 : 0 ))
+@d mp_out(A) (double)((A)/(256*256*16))
+@d divisor (256*256)
+@d double2angle(a) (int)mp_floor(a*256.0*256.0*16.0)
+
+@<Declare unary action...@>=
+static angle mp_bezier_slope(MP mp, integer AX,integer AY,integer BX,integer BY,
+ integer CX,integer CY,integer DX,integer DY);
+
+@ @c
+static angle mp_bezier_slope(MP mp, integer AX,integer AY,integer BX,integer BY,
+ integer CX,integer CY,integer DX,integer DY) {
+ double a, b, c;
+ integer deltax,deltay;
+ double ax,ay,bx,by,cx,cy,dx,dy;
+ angle xi = 0, xo = 0, xm = 0;
+ double res = 0;
+ ax=(double)(AX/divisor); ay=(double)(AY/divisor);
+ bx=(double)(BX/divisor); by=(double)(BY/divisor);
+ cx=(double)(CX/divisor); cy=(double)(CY/divisor);
+ dx=(double)(DX/divisor); dy=(double)(DY/divisor);
+
+ deltax = (BX-AX); deltay = (BY-AY);
+ if (deltax==0 && deltay == 0) { deltax=(CX-AX); deltay=(CY-AY); }
+ if (deltax==0 && deltay == 0) { deltax=(DX-AX); deltay=(DY-AY); }
+ xi = mp_an_angle(mp,deltax,deltay);
+
+ deltax = (CX-BX); deltay = (CY-BY);
+ xm = mp_an_angle(mp,deltax,deltay);
+
+ deltax = (DX-CX); deltay = (DY-CY);
+ if (deltax==0 && deltay == 0) { deltax=(DX-BX); deltay=(DY-BY); }
+ if (deltax==0 && deltay == 0) { deltax=(DX-AX); deltay=(DY-AY); }
+ xo = mp_an_angle(mp,deltax,deltay);
+
+ a = (bx-ax)*(cy-by) - (cx-bx)*(by-ay); /* a = (bp-ap)x(cp-bp); */
+ b = (bx-ax)*(dy-cy) - (by-ay)*(dx-cx);; /* b = (bp-ap)x(dp-cp);*/
+ c = (cx-bx)*(dy-cy) - (dx-cx)*(cy-by); /* c = (cp-bp)x(dp-cp);*/
+
+ if ((a==0)&&(c==0)) {
+ res = (b==0 ? 0 : (mp_out(xo)-mp_out(xi)));
+ } else if ((a==0)||(c==0)) {
+ if ((mp_sign(b) == mp_sign(a)) || (mp_sign(b) == mp_sign(c))) {
+ res = mp_out(xo)-mp_out(xi); /* ? */
+ if (res<-180.0)
+ res += 360.0;
+ else if (res>180.0)
+ res -= 360.0;
+ } else {
+ res = mp_out(xo)-mp_out(xi); /* ? */
+ }
+ } else if ((mp_sign(a)*mp_sign(c))<0) {
+ res = mp_out(xo)-mp_out(xi); /* ? */
+ if (res<-180.0)
+ res += 360.0;
+ else if (res>180.0)
+ res -= 360.0;
+ } else {
+ if (mp_sign(a) == mp_sign(b)) {
+ res = mp_out(xo)-mp_out(xi); /* ? */
+ if (res<-180.0)
+ res += 360.0;
+ else if (res>180.0)
+ res -= 360.0;
+ } else {
+ if ((b*b) == (4*a*c)) {
+ res = (double)bezier_error;
+ } else if ((b*b) < (4*a*c)) {
+ res = mp_out(xo)-mp_out(xi); /* ? */
+ if (res<=0.0 &&res>-180.0)
+ res += 360.0;
+ else if (res>=0.0 && res<180.0)
+ res -= 360.0;
+ } else {
+ res = mp_out(xo)-mp_out(xi);
+ if (res<-180.0)
+ res += 360.0;
+ else if (res>180.0)
+ res -= 360.0;
+ }
+ }
+ }
+ return double2angle(res);
+}
+
+@
+@d p_nextnext mp_link(mp_link(p))
+@d p_next mp_link(p)
+@d seven_twenty_deg 05500000000 /* $720\cdot2^{20}$, represents $720^\circ$ */
+
+@<Declare unary action...@>=
+static scaled mp_new_turn_cycles (MP mp,pointer c) {
+ angle res,ang; /* the angles of intermediate results */
+ scaled turns; /* the turn counter */
+ pointer p; /* for running around the path */
+ integer xp,yp; /* coordinates of next point */
+ integer x,y; /* helper coordinates */
+ angle in_angle,out_angle; /* helper angles */
+ unsigned old_setting; /* saved |selector| setting */
+ res=0;
+ turns= 0;
+ p=c;
+ old_setting = mp->selector; mp->selector=term_only;
+ if ( mp->internal[mp_tracing_commands]>unity ) {
+ mp_begin_diagnostic(mp);
+ mp_print_nl(mp, "");
+ mp_end_diagnostic(mp, false);
+ }
+ do {
+ xp = mp_x_coord(p_next); yp = mp_y_coord(p_next);
+ ang = mp_bezier_slope(mp,mp_x_coord(p), mp_y_coord(p), mp_right_x(p), mp_right_y(p),
+ mp_left_x(p_next), mp_left_y(p_next), xp, yp);
+ if ( ang>seven_twenty_deg ) {
+ print_err("Strange path");
+ mp_error(mp);
+ mp->selector=old_setting;
+ return 0;
+ }
+ res = res + ang;
+ if ( res > one_eighty_deg ) {
+ res = res - three_sixty_deg;
+ turns = turns + unity;
+ }
+ if ( res <= -one_eighty_deg ) {
+ res = res + three_sixty_deg;
+ turns = turns - unity;
+ }
+ /* incoming angle at next point */
+ x = mp_left_x(p_next); y = mp_left_y(p_next);
+ if ( (xp==x)&&(yp==y) ) { x = mp_right_x(p); y = mp_right_y(p); };
+ if ( (xp==x)&&(yp==y) ) { x = mp_x_coord(p); y = mp_y_coord(p); };
+ in_angle = mp_an_angle(mp, xp - x, yp - y);
+ /* outgoing angle at next point */
+ x = mp_right_x(p_next); y = mp_right_y(p_next);
+ if ( (xp==x)&&(yp==y) ) { x = mp_left_x(p_nextnext); y = mp_left_y(p_nextnext); };
+ if ( (xp==x)&&(yp==y) ) { x = mp_x_coord(p_nextnext); y = mp_y_coord(p_nextnext); };
+ out_angle = mp_an_angle(mp, x - xp, y- yp);
+ ang = (out_angle - in_angle);
+ reduce_angle(ang);
+ if ( ang!=0 ) {
+ res = res + ang;
+ if ( res >= one_eighty_deg ) {
+ res = res - three_sixty_deg;
+ turns = turns + unity;
+ };
+ if ( res <= -one_eighty_deg ) {
+ res = res + three_sixty_deg;
+ turns = turns - unity;
+ };
+ };
+ p = mp_link(p);
+ } while (p!=c);
+ mp->selector=old_setting;
+ return turns;
+}
+
+
+@ This code is based on Bogus\l{}av Jackowski's
+|emergency_turningnumber| macro, with some minor changes by Taco
+Hoekwater. The macro code looked more like this:
+{\obeylines
+vardef turning\_number primary p =
+~~save res, ang, turns;
+~~res := 0;
+~~if length p <= 2:
+~~~~if Angle ((point 0 of p) - (postcontrol 0 of p)) >= 0: 1 else: -1 fi
+~~else:
+~~~~for t = 0 upto length p-1 :
+~~~~~~angc := Angle ((point t+1 of p) - (point t of p))
+~~~~~~~~- Angle ((point t of p) - (point t-1 of p));
+~~~~~~if angc > 180: angc := angc - 360; fi;
+~~~~~~if angc < -180: angc := angc + 360; fi;
+~~~~~~res := res + angc;
+~~~~endfor;
+~~res/360
+~~fi
+enddef;}
+The general idea is to calculate only the sum of the angles of
+straight lines between the points, of a path, not worrying about cusps
+or self-intersections in the segments at all. If the segment is not
+well-behaved, the result is not necesarily correct. But the old code
+was not always correct either, and worse, it sometimes failed for
+well-behaved paths as well. All known bugs that were triggered by the
+original code no longer occur with this code, and it runs roughly 3
+times as fast because the algorithm is much simpler.
+
+@ It is possible to overflow the return value of the |turn_cycles|
+function when the path is sufficiently long and winding, but I am not
+going to bother testing for that. In any case, it would only return
+the looped result value, which is not a big problem.
+
+The macro code for the repeat loop was a bit nicer to look
+at than the pascal code, because it could use |point -1 of p|. In
+pascal, the fastest way to loop around the path is not to look
+backward once, but forward twice. These defines help hide the trick.
+
+@d p_to mp_link(mp_link(p))
+@d p_here mp_link(p)
+@d p_from p
+
+@<Declare unary action...@>=
+static scaled mp_turn_cycles (MP mp,pointer c) {
+ angle res,ang; /* the angles of intermediate results */
+ scaled turns; /* the turn counter */
+ pointer p; /* for running around the path */
+ res=0; turns= 0; p=c;
+ do {
+ ang = mp_an_angle (mp, mp_x_coord(p_to) - mp_x_coord(p_here),
+ mp_y_coord(p_to) - mp_y_coord(p_here))
+ - mp_an_angle (mp, mp_x_coord(p_here) - mp_x_coord(p_from),
+ mp_y_coord(p_here) - mp_y_coord(p_from));
+ reduce_angle(ang);
+ res = res + ang;
+ if ( res >= three_sixty_deg ) {
+ res = res - three_sixty_deg;
+ turns = turns + unity;
+ };
+ if ( res <= -three_sixty_deg ) {
+ res = res + three_sixty_deg;
+ turns = turns - unity;
+ };
+ p = mp_link(p);
+ } while (p!=c);
+ return turns;
+}
+
+@ @<Declare unary action...@>=
+static scaled mp_turn_cycles_wrapper (MP mp,pointer c) {
+ scaled nval,oval;
+ scaled saved_t_o; /* tracing\_online saved */
+ if ( (mp_link(c)==c)||(mp_link(mp_link(c))==c) ) {
+ if ( mp_an_angle (mp, mp_x_coord(c) - mp_right_x(c), mp_y_coord(c) - mp_right_y(c)) > 0 )
+ return unity;
+ else
+ return -unity;
+ } else {
+ nval = mp_new_turn_cycles(mp, c);
+ oval = mp_turn_cycles(mp, c);
+ if ( nval!=oval ) {
+ saved_t_o=mp->internal[mp_tracing_online];
+ mp->internal[mp_tracing_online]=unity;
+ mp_begin_diagnostic(mp);
+ mp_print_nl (mp, "Warning: the turningnumber algorithms do not agree."
+ " The current computed value is ");
+ mp_print_scaled(mp, nval);
+ mp_print(mp, ", but the 'connect-the-dots' algorithm returned ");
+ mp_print_scaled(mp, oval);
+ mp_end_diagnostic(mp, false);
+ mp->internal[mp_tracing_online]=saved_t_o;
+ }
+ return nval;
+ }
+}
+
+@ @d type_range(A,B) {
+ if ( (mp->cur_type>=(A)) && (mp->cur_type<=(B)) )
+ mp_flush_cur_exp(mp, true_code);
+ else mp_flush_cur_exp(mp, false_code);
+ mp->cur_type=mp_boolean_type;
+ }
+@d type_test(A) {
+ if ( mp->cur_type==(A) ) mp_flush_cur_exp(mp, true_code);
+ else mp_flush_cur_exp(mp, false_code);
+ mp->cur_type=mp_boolean_type;
+ }
+
+@<Additional cases of unary operators@>=
+case mp_boolean_type:
+ type_range(mp_boolean_type,mp_unknown_boolean); break;
+case mp_string_type:
+ type_range(mp_string_type,mp_unknown_string); break;
+case mp_pen_type:
+ type_range(mp_pen_type,mp_unknown_pen); break;
+case mp_path_type:
+ type_range(mp_path_type,mp_unknown_path); break;
+case mp_picture_type:
+ type_range(mp_picture_type,mp_unknown_picture); break;
+case mp_transform_type: case mp_color_type: case mp_cmykcolor_type:
+case mp_pair_type:
+ type_test(c); break;
+case mp_numeric_type:
+ type_range(mp_known,mp_independent); break;
+case known_op: case unknown_op:
+ mp_test_known(mp, c); break;
+
+@ @<Declare unary action procedures@>=
+static void mp_test_known (MP mp,quarterword c) {
+ int b; /* is the current expression known? */
+ pointer p,q; /* locations in a big node */
+ b=false_code;
+ switch (mp->cur_type) {
+ case mp_vacuous: case mp_boolean_type: case mp_string_type:
+ case mp_pen_type: case mp_path_type: case mp_picture_type:
+ case mp_known:
+ b=true_code;
+ break;
+ case mp_transform_type:
+ case mp_color_type: case mp_cmykcolor_type: case mp_pair_type:
+ p=value(mp->cur_exp);
+ q=p+mp->big_node_size[mp->cur_type];
+ do {
+ q=q-2;
+ if ( mp_type(q)!=mp_known )
+ goto DONE;
+ } while (q!=p);
+ b=true_code;
+ DONE:
+ break;
+ default:
+ break;
+ }
+ if ( c==known_op ) mp_flush_cur_exp(mp, b);
+ else mp_flush_cur_exp(mp, true_code+false_code-b);
+ mp->cur_type=mp_boolean_type;
+}
+
+@ @<Additional cases of unary operators@>=
+case cycle_op:
+ if ( mp->cur_type!=mp_path_type ) mp_flush_cur_exp(mp, false_code);
+ else if ( mp_left_type(mp->cur_exp)!=mp_endpoint ) mp_flush_cur_exp(mp, true_code);
+ else mp_flush_cur_exp(mp, false_code);
+ mp->cur_type=mp_boolean_type;
+ break;
+
+@ @<Additional cases of unary operators@>=
+case arc_length:
+ if ( mp->cur_type==mp_pair_type ) mp_pair_to_path(mp);
+ if ( mp->cur_type!=mp_path_type ) mp_bad_unary(mp, arc_length);
+ else mp_flush_cur_exp(mp, mp_get_arc_length(mp, mp->cur_exp));
+ break;
+
+@ Here we use the fact that |c-filled_op+fill_code| is the desired graphical
+object |type|.
+@^data structure assumptions@>
+
+@<Additional cases of unary operators@>=
+case filled_op:
+case stroked_op:
+case textual_op:
+case clipped_op:
+case bounded_op:
+ if ( mp->cur_type!=mp_picture_type ) mp_flush_cur_exp(mp, false_code);
+ else if ( mp_link(dummy_loc(mp->cur_exp))==null ) mp_flush_cur_exp(mp, false_code);
+ else if ( mp_type(mp_link(dummy_loc(mp->cur_exp)))==c+mp_fill_code-filled_op )
+ mp_flush_cur_exp(mp, true_code);
+ else mp_flush_cur_exp(mp, false_code);
+ mp->cur_type=mp_boolean_type;
+ break;
+
+@ @<Additional cases of unary operators@>=
+case make_pen_op:
+ if ( mp->cur_type==mp_pair_type ) mp_pair_to_path(mp);
+ if ( mp->cur_type!=mp_path_type ) mp_bad_unary(mp, make_pen_op);
+ else {
+ mp->cur_type=mp_pen_type;
+ mp->cur_exp=mp_make_pen(mp, mp->cur_exp,true);
+ };
+ break;
+case make_path_op:
+ if ( mp->cur_type!=mp_pen_type ) mp_bad_unary(mp, make_path_op);
+ else {
+ mp->cur_type=mp_path_type;
+ mp_make_path(mp, mp->cur_exp);
+ };
+ break;
+case reverse:
+ if ( mp->cur_type==mp_path_type ) {
+ p=mp_htap_ypoc(mp, mp->cur_exp);
+ if ( mp_right_type(p)==mp_endpoint ) p=mp_link(p);
+ mp_toss_knot_list(mp, mp->cur_exp); mp->cur_exp=p;
+ } else if ( mp->cur_type==mp_pair_type ) mp_pair_to_path(mp);
+ else mp_bad_unary(mp, reverse);
+ break;
+
+@ The |pair_value| routine changes the current expression to a
+given ordered pair of values.
+
+@<Declare unary action procedures@>=
+static void mp_pair_value (MP mp,scaled x, scaled y) {
+ pointer p; /* a pair node */
+ p=mp_get_node(mp, value_node_size);
+ mp_flush_cur_exp(mp, p); mp->cur_type=mp_pair_type;
+ mp_type(p)=mp_pair_type; mp_name_type(p)=mp_capsule; mp_init_big_node(mp, p);
+ p=value(p);
+ mp_type(x_part_loc(p))=mp_known; value(x_part_loc(p))=x;
+ mp_type(y_part_loc(p))=mp_known; value(y_part_loc(p))=y;
+}
+
+@ @<Additional cases of unary operators@>=
+case ll_corner_op:
+ if ( ! mp_get_cur_bbox(mp) ) mp_bad_unary(mp, ll_corner_op);
+ else mp_pair_value(mp, mp_minx, mp_miny);
+ break;
+case lr_corner_op:
+ if ( ! mp_get_cur_bbox(mp) ) mp_bad_unary(mp, lr_corner_op);
+ else mp_pair_value(mp, mp_maxx, mp_miny);
+ break;
+case ul_corner_op:
+ if ( ! mp_get_cur_bbox(mp) ) mp_bad_unary(mp, ul_corner_op);
+ else mp_pair_value(mp, mp_minx, mp_maxy);
+ break;
+case ur_corner_op:
+ if ( ! mp_get_cur_bbox(mp) ) mp_bad_unary(mp, ur_corner_op);
+ else mp_pair_value(mp, mp_maxx, mp_maxy);
+ break;
+
+@ Here is a function that sets |minx|, |maxx|, |miny|, |maxy| to the bounding
+box of the current expression. The boolean result is |false| if the expression
+has the wrong type.
+
+@<Declare unary action procedures@>=
+static boolean mp_get_cur_bbox (MP mp) {
+ switch (mp->cur_type) {
+ case mp_picture_type:
+ mp_set_bbox(mp, mp->cur_exp,true);
+ if ( minx_val(mp->cur_exp)>maxx_val(mp->cur_exp) ) {
+ mp_minx=0; mp_maxx=0; mp_miny=0; mp_maxy=0;
+ } else {
+ mp_minx=minx_val(mp->cur_exp);
+ mp_maxx=maxx_val(mp->cur_exp);
+ mp_miny=miny_val(mp->cur_exp);
+ mp_maxy=maxy_val(mp->cur_exp);
+ }
+ break;
+ case mp_path_type:
+ mp_path_bbox(mp, mp->cur_exp);
+ break;
+ case mp_pen_type:
+ mp_pen_bbox(mp, mp->cur_exp);
+ break;
+ default:
+ return false;
+ }
+ return true;
+}
+
+@ @<Additional cases of unary operators@>=
+case read_from_op:
+case close_from_op:
+ if ( mp->cur_type!=mp_string_type ) mp_bad_unary(mp, c);
+ else mp_do_read_or_close(mp,c);
+ break;
+
+@ Here is a routine that interprets |cur_exp| as a file name and tries to read
+a line from the file or to close the file.
+
+@<Declare unary action procedures@>=
+static void mp_do_read_or_close (MP mp,quarterword c) {
+ readf_index n,n0; /* indices for searching |rd_fname| */
+ @<Find the |n| where |rd_fname[n]=cur_exp|; if |cur_exp| must be inserted,
+ call |start_read_input| and |goto found| or |not_found|@>;
+ mp_begin_file_reading(mp);
+ name=is_read;
+ if ( mp_input_ln(mp, mp->rd_file[n] ) )
+ goto FOUND;
+ mp_end_file_reading(mp);
+NOT_FOUND:
+ @<Record the end of file and set |cur_exp| to a dummy value@>;
+ return;
+CLOSE_FILE:
+ mp_flush_cur_exp(mp, 0); mp->cur_type=mp_vacuous;
+ return;
+FOUND:
+ mp_flush_cur_exp(mp, 0);
+ mp_finish_read(mp);
+}
+
+@ Free slots in the |rd_file| and |rd_fname| arrays are marked with NULL's in
+|rd_fname|.
+
+@<Find the |n| where |rd_fname[n]=cur_exp|...@>=
+{
+ char *fn;
+ n=mp->read_files;
+ n0=mp->read_files;
+ fn = str(mp->cur_exp);
+ while (mp_xstrcmp(fn,mp->rd_fname[n])!=0) {
+ if ( n>0 ) {
+ decr(n);
+ } else if ( c==close_from_op ) {
+ goto CLOSE_FILE;
+ } else {
+ if ( n0==mp->read_files ) {
+ if ( mp->read_files<mp->max_read_files ) {
+ incr(mp->read_files);
+ } else {
+ void **rd_file;
+ char **rd_fname;
+ readf_index l,k;
+ l = mp->max_read_files + (mp->max_read_files/4);
+ rd_file = xmalloc((l+1), sizeof(void *));
+ rd_fname = xmalloc((l+1), sizeof(char *));
+ for (k=0;k<=l;k++) {
+ if (k<=mp->max_read_files) {
+ rd_file[k]=mp->rd_file[k];
+ rd_fname[k]=mp->rd_fname[k];
+ } else {
+ rd_file[k]=0;
+ rd_fname[k]=NULL;
+ }
+ }
+ xfree(mp->rd_file); xfree(mp->rd_fname);
+ mp->max_read_files = l;
+ mp->rd_file = rd_file;
+ mp->rd_fname = rd_fname;
+ }
+ }
+ n=n0;
+ if ( mp_start_read_input(mp,fn,n) )
+ goto FOUND;
+ else
+ goto NOT_FOUND;
+ }
+ if ( mp->rd_fname[n]==NULL ) { n0=n; }
+ }
+ if ( c==close_from_op ) {
+ (mp->close_file)(mp,mp->rd_file[n]);
+ goto NOT_FOUND;
+ }
+}
+
+@ @<Record the end of file and set |cur_exp| to a dummy value@>=
+xfree(mp->rd_fname[n]);
+mp->rd_fname[n]=NULL;
+if ( n==mp->read_files-1 ) mp->read_files=n;
+if ( c==close_from_op )
+ goto CLOSE_FILE;
+mp_flush_cur_exp(mp, mp->eof_line);
+mp->cur_type=mp_string_type
+
+@ The string denoting end-of-file is a one-byte string at position zero, by definition
+
+@<Glob...@>=
+str_number eof_line;
+
+@ @<Set init...@>=
+mp->eof_line=0;
+
+@ Finally, we have the operations that combine a capsule~|p|
+with the current expression.
+
+@d binary_return { mp_finish_binary(mp, old_p, old_exp); return; }
+
+@c @<Declare binary action procedures@>
+static void mp_finish_binary (MP mp, pointer old_p, pointer old_exp ){
+ check_arith;
+ @<Recycle any sidestepped |independent| capsules@>;
+}
+static void mp_do_binary (MP mp,pointer p, quarterword c) {
+ pointer q,r,rr; /* for list manipulation */
+ pointer old_p,old_exp; /* capsules to recycle */
+ integer v; /* for numeric manipulation */
+ check_arith;
+ if ( mp->internal[mp_tracing_commands]>two ) {
+ @<Trace the current binary operation@>;
+ }
+ @<Sidestep |independent| cases in capsule |p|@>;
+ @<Sidestep |independent| cases in the current expression@>;
+ switch (c) {
+ case plus: case minus:
+ @<Add or subtract the current expression from |p|@>;
+ break;
+ @<Additional cases of binary operators@>;
+ }; /* there are no other cases */
+ mp_recycle_value(mp, p);
+ mp_free_node(mp, p,value_node_size); /* |return| to avoid this */
+ mp_finish_binary(mp, old_p, old_exp);
+}
+
+@ @<Declare binary action...@>=
+static void mp_bad_binary (MP mp,pointer p, quarterword c) {
+ mp_disp_err(mp, p,"");
+ exp_err("Not implemented: ");
+@.Not implemented...@>
+ if ( c>=min_of ) mp_print_op(mp, c);
+ mp_print_known_or_unknown_type(mp, mp_type(p),p);
+ if ( c>=min_of ) mp_print(mp, "of"); else mp_print_op(mp, c);
+ mp_print_known_or_unknown_type(mp, mp->cur_type,mp->cur_exp);
+ help3("I'm afraid I don't know how to apply that operation to that",
+ "combination of types. Continue, and I'll return the second",
+ "argument (see above) as the result of the operation.");
+ mp_put_get_error(mp);
+}
+static void mp_bad_envelope_pen (MP mp) {
+ mp_disp_err(mp, null,"");
+ exp_err("Not implemented: envelope(elliptical pen)of(path)");
+@.Not implemented...@>
+ help3("I'm afraid I don't know how to apply that operation to that",
+ "combination of types. Continue, and I'll return the second",
+ "argument (see above) as the result of the operation.");
+ mp_put_get_error(mp);
+}
+
+@ @<Trace the current binary operation@>=
+{
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "{(");
+ mp_print_exp(mp,p,0); /* show the operand, but not verbosely */
+ mp_print_char(mp,xord(')')); mp_print_op(mp,c); mp_print_char(mp,xord('('));
+ mp_print_exp(mp,null,0); mp_print(mp,")}");
+ mp_end_diagnostic(mp, false);
+}
+
+@ Several of the binary operations are potentially complicated by the
+fact that |independent| values can sneak into capsules. For example,
+we've seen an instance of this difficulty in the unary operation
+of negation. In order to reduce the number of cases that need to be
+handled, we first change the two operands (if necessary)
+to rid them of |independent| components. The original operands are
+put into capsules called |old_p| and |old_exp|, which will be
+recycled after the binary operation has been safely carried out.
+
+@<Recycle any sidestepped |independent| capsules@>=
+if ( old_p!=null ) {
+ mp_recycle_value(mp, old_p); mp_free_node(mp, old_p,value_node_size);
+}
+if ( old_exp!=null ) {
+ mp_recycle_value(mp, old_exp); mp_free_node(mp, old_exp,value_node_size);
+}
+
+@ A big node is considered to be ``tarnished'' if it contains at least one
+independent component. We will define a simple function called `|tarnished|'
+that returns |null| if and only if its argument is not tarnished.
+
+@<Sidestep |independent| cases in capsule |p|@>=
+switch (mp_type(p)) {
+case mp_transform_type:
+case mp_color_type:
+case mp_cmykcolor_type:
+case mp_pair_type:
+ old_p=mp_tarnished(mp, p);
+ break;
+case mp_independent: old_p=mp_void; break;
+default: old_p=null; break;
+}
+if ( old_p!=null ) {
+ q=mp_stash_cur_exp(mp); old_p=p; mp_make_exp_copy(mp, old_p);
+ p=mp_stash_cur_exp(mp); mp_unstash_cur_exp(mp, q);
+}
+
+@ @<Sidestep |independent| cases in the current expression@>=
+switch (mp->cur_type) {
+case mp_transform_type:
+case mp_color_type:
+case mp_cmykcolor_type:
+case mp_pair_type:
+ old_exp=mp_tarnished(mp, mp->cur_exp);
+ break;
+case mp_independent:old_exp=mp_void; break;
+default: old_exp=null; break;
+}
+if ( old_exp!=null ) {
+ old_exp=mp->cur_exp; mp_make_exp_copy(mp, old_exp);
+}
+
+@ @<Declare binary action...@>=
+static pointer mp_tarnished (MP mp,pointer p) {
+ pointer q; /* beginning of the big node */
+ pointer r; /* current position in the big node */
+ q=value(p); r=q+mp->big_node_size[mp_type(p)];
+ do {
+ r=r-2;
+ if ( mp_type(r)==mp_independent ) return mp_void;
+ } while (r!=q);
+ return null;
+}
+
+@ @<Add or subtract the current expression from |p|@>=
+if ( (mp->cur_type<mp_color_type)||(mp_type(p)<mp_color_type) ) {
+ mp_bad_binary(mp, p,c);
+} else {
+ if ((mp->cur_type>mp_pair_type)&&(mp_type(p)>mp_pair_type) ) {
+ mp_add_or_subtract(mp, p,null,c);
+ } else {
+ if ( mp->cur_type!=mp_type(p) ) {
+ mp_bad_binary(mp, p,c);
+ } else {
+ q=value(p); r=value(mp->cur_exp);
+ rr=r+mp->big_node_size[mp->cur_type];
+ while ( r<rr ) {
+ mp_add_or_subtract(mp, q,r,c);
+ q=q+2; r=r+2;
+ }
+ }
+ }
+}
+
+@ The first argument to |add_or_subtract| is the location of a value node
+in a capsule or pair node that will soon be recycled. The second argument
+is either a location within a pair or transform node of |cur_exp|,
+or it is null (which means that |cur_exp| itself should be the second
+argument). The third argument is either |plus| or |minus|.
+
+The sum or difference of the numeric quantities will replace the second
+operand. Arithmetic overflow may go undetected; users aren't supposed to
+be monkeying around with really big values.
+@^overflow in arithmetic@>
+
+@<Declare binary action...@>=
+@<Declare the procedure called |dep_finish|@>
+static void mp_add_or_subtract (MP mp,pointer p, pointer q, quarterword c) {
+ quarterword s,t; /* operand types */
+ pointer r; /* list traverser */
+ integer v; /* second operand value */
+ if ( q==null ) {
+ t=mp->cur_type;
+ if ( t<mp_dependent ) v=mp->cur_exp; else v=dep_list(mp->cur_exp);
+ } else {
+ t=mp_type(q);
+ if ( t<mp_dependent ) v=value(q); else v=dep_list(q);
+ }
+ if ( t==mp_known ) {
+ if ( c==minus ) negate(v);
+ if ( mp_type(p)==mp_known ) {
+ v=mp_slow_add(mp, value(p),v);
+ if ( q==null ) mp->cur_exp=v; else value(q)=v;
+ return;
+ }
+ @<Add a known value to the constant term of |dep_list(p)|@>;
+ } else {
+ if ( c==minus ) mp_negate_dep_list(mp, v);
+ @<Add operand |p| to the dependency list |v|@>;
+ }
+}
+
+@ @<Add a known value to the constant term of |dep_list(p)|@>=
+r=dep_list(p);
+while ( mp_info(r)!=null ) r=mp_link(r);
+value(r)=mp_slow_add(mp, value(r),v);
+if ( q==null ) {
+ q=mp_get_node(mp, value_node_size); mp->cur_exp=q; mp->cur_type=mp_type(p);
+ mp_name_type(q)=mp_capsule;
+}
+dep_list(q)=dep_list(p); mp_type(q)=mp_type(p);
+prev_dep(q)=prev_dep(p); mp_link(prev_dep(p))=q;
+mp_type(p)=mp_known; /* this will keep the recycler from collecting non-garbage */
+
+@ We prefer |dependent| lists to |mp_proto_dependent| ones, because it is
+nice to retain the extra accuracy of |fraction| coefficients.
+But we have to handle both kinds, and mixtures too.
+
+@<Add operand |p| to the dependency list |v|@>=
+if ( mp_type(p)==mp_known ) {
+ @<Add the known |value(p)| to the constant term of |v|@>;
+} else {
+ s=mp_type(p); r=dep_list(p);
+ if ( t==mp_dependent ) {
+ if ( s==mp_dependent ) {
+ if ( mp_max_coef(mp, r)+mp_max_coef(mp, v)<coef_bound ) {
+ v=mp_p_plus_q(mp, v,r,mp_dependent); goto DONE;
+ }
+ } /* |fix_needed| will necessarily be false */
+ t=mp_proto_dependent;
+ v=mp_p_over_v(mp, v,unity,mp_dependent,mp_proto_dependent);
+ }
+ if ( s==mp_proto_dependent ) v=mp_p_plus_q(mp, v,r,mp_proto_dependent);
+ else v=mp_p_plus_fq(mp, v,unity,r,mp_proto_dependent,mp_dependent);
+ DONE:
+ @<Output the answer, |v| (which might have become |known|)@>;
+}
+
+@ @<Add the known |value(p)| to the constant term of |v|@>=
+{
+ while ( mp_info(v)!=null ) v=mp_link(v);
+ value(v)=mp_slow_add(mp, value(p),value(v));
+}
+
+@ @<Output the answer, |v| (which might have become |known|)@>=
+if ( q!=null ) mp_dep_finish(mp, v,q,t);
+else { mp->cur_type=t; mp_dep_finish(mp, v,null,t); }
+
+@ Here's the current situation: The dependency list |v| of type |t|
+should either be put into the current expression (if |q=null|) or
+into location |q| within a pair node (otherwise). The destination (|cur_exp|
+or |q|) formerly held a dependency list with the same
+final pointer as the list |v|.
+
+@<Declare the procedure called |dep_finish|@>=
+static void mp_dep_finish (MP mp, pointer v, pointer q, quarterword t) {
+ pointer p; /* the destination */
+ scaled vv; /* the value, if it is |known| */
+ if ( q==null ) p=mp->cur_exp; else p=q;
+ dep_list(p)=v; mp_type(p)=t;
+ if ( mp_info(v)==null ) {
+ vv=value(v);
+ if ( q==null ) {
+ mp_flush_cur_exp(mp, vv);
+ } else {
+ mp_recycle_value(mp, p); mp_type(q)=mp_known; value(q)=vv;
+ }
+ } else if ( q==null ) {
+ mp->cur_type=t;
+ }
+ if ( mp->fix_needed ) mp_fix_dependencies(mp);
+}
+
+@ Let's turn now to the six basic relations of comparison.
+
+@<Additional cases of binary operators@>=
+case less_than: case less_or_equal: case greater_than:
+case greater_or_equal: case equal_to: case unequal_to:
+ check_arith; /* at this point |arith_error| should be |false|? */
+ if ( (mp->cur_type>mp_pair_type)&&(mp_type(p)>mp_pair_type) ) {
+ mp_add_or_subtract(mp, p,null,minus); /* |cur_exp:=(p)-cur_exp| */
+ } else if ( mp->cur_type!=mp_type(p) ) {
+ mp_bad_binary(mp, p,c); goto DONE;
+ } else if ( mp->cur_type==mp_string_type ) {
+ mp_flush_cur_exp(mp, mp_str_vs_str(mp, value(p),mp->cur_exp));
+ } else if ((mp->cur_type==mp_unknown_string)||
+ (mp->cur_type==mp_unknown_boolean) ) {
+ @<Check if unknowns have been equated@>;
+ } else if ( (mp->cur_type<=mp_pair_type)&&(mp->cur_type>=mp_transform_type)) {
+ @<Reduce comparison of big nodes to comparison of scalars@>;
+ } else if ( mp->cur_type==mp_boolean_type ) {
+ mp_flush_cur_exp(mp, mp->cur_exp-value(p));
+ } else {
+ mp_bad_binary(mp, p,c); goto DONE;
+ }
+ @<Compare the current expression with zero@>;
+DONE:
+ mp->arith_error=false; /* ignore overflow in comparisons */
+ break;
+
+@ @<Compare the current expression with zero@>=
+if ( mp->cur_type!=mp_known ) {
+ if ( mp->cur_type<mp_known ) {
+ mp_disp_err(mp, p,"");
+ help1("The quantities shown above have not been equated.")
+ } else {
+ help2("Oh dear. I can\'t decide if the expression above is positive,",
+ "negative, or zero. So this comparison test won't be `true'.");
+ }
+ exp_err("Unknown relation will be considered false");
+@.Unknown relation...@>
+ mp_put_get_flush_error(mp, false_code);
+} else {
+ switch (c) {
+ case less_than: boolean_reset(mp->cur_exp<0); break;
+ case less_or_equal: boolean_reset(mp->cur_exp<=0); break;
+ case greater_than: boolean_reset(mp->cur_exp>0); break;
+ case greater_or_equal: boolean_reset(mp->cur_exp>=0); break;
+ case equal_to: boolean_reset(mp->cur_exp==0); break;
+ case unequal_to: boolean_reset(mp->cur_exp!=0); break;
+ }; /* there are no other cases */
+}
+mp->cur_type=mp_boolean_type
+
+@ When two unknown strings are in the same ring, we know that they are
+equal. Otherwise, we don't know whether they are equal or not, so we
+make no change.
+
+@<Check if unknowns have been equated@>=
+{
+ q=value(mp->cur_exp);
+ while ( (q!=mp->cur_exp)&&(q!=p) ) q=value(q);
+ if ( q==p ) mp_flush_cur_exp(mp, 0);
+}
+
+@ @<Reduce comparison of big nodes to comparison of scalars@>=
+{
+ q=value(p); r=value(mp->cur_exp);
+ rr=r+mp->big_node_size[mp->cur_type]-2;
+ while (1) { mp_add_or_subtract(mp, q,r,minus);
+ if ( mp_type(r)!=mp_known ) break;
+ if ( value(r)!=0 ) break;
+ if ( r==rr ) break;
+ q=q+2; r=r+2;
+ }
+ mp_take_part(mp, mp_name_type(r)+x_part-mp_x_part_sector);
+}
+
+@ Here we use the sneaky fact that |and_op-false_code=or_op-true_code|.
+
+@<Additional cases of binary operators@>=
+case and_op:
+case or_op:
+ if ( (mp_type(p)!=mp_boolean_type)||(mp->cur_type!=mp_boolean_type) )
+ mp_bad_binary(mp, p,c);
+ else if ( value(p)==c+false_code-and_op ) mp->cur_exp=value(p);
+ break;
+
+@ @<Additional cases of binary operators@>=
+case times:
+ if ( (mp->cur_type<mp_color_type)||(mp_type(p)<mp_color_type) ) {
+ mp_bad_binary(mp, p,times);
+ } else if ( (mp->cur_type==mp_known)||(mp_type(p)==mp_known) ) {
+ @<Multiply when at least one operand is known@>;
+ } else if ( (mp_nice_color_or_pair(mp, p,mp_type(p))&&(mp->cur_type>mp_pair_type))
+ ||(mp_nice_color_or_pair(mp, mp->cur_exp,mp->cur_type)&&
+ (mp_type(p)>mp_pair_type)) ) {
+ mp_hard_times(mp, p);
+ binary_return;
+ } else {
+ mp_bad_binary(mp, p,times);
+ }
+ break;
+
+@ @<Multiply when at least one operand is known@>=
+{
+ if ( mp_type(p)==mp_known ) {
+ v=value(p); mp_free_node(mp, p,value_node_size);
+ } else {
+ v=mp->cur_exp; mp_unstash_cur_exp(mp, p);
+ }
+ if ( mp->cur_type==mp_known ) {
+ mp->cur_exp=mp_take_scaled(mp, mp->cur_exp,v);
+ } else if ( (mp->cur_type==mp_pair_type)||
+ (mp->cur_type==mp_color_type)||
+ (mp->cur_type==mp_cmykcolor_type) ) {
+ p=value(mp->cur_exp)+mp->big_node_size[mp->cur_type];
+ do {
+ p=p-2; mp_dep_mult(mp, p,v,true);
+ } while (p!=value(mp->cur_exp));
+ } else {
+ mp_dep_mult(mp, null,v,true);
+ }
+ binary_return;
+}
+
+@ @<Declare binary action...@>=
+static void mp_dep_mult (MP mp,pointer p, integer v, boolean v_is_scaled) {
+ pointer q; /* the dependency list being multiplied by |v| */
+ quarterword s,t; /* its type, before and after */
+ if ( p==null ) {
+ q=mp->cur_exp;
+ } else if ( mp_type(p)!=mp_known ) {
+ q=p;
+ } else {
+ if ( v_is_scaled ) value(p)=mp_take_scaled(mp, value(p),v);
+ else value(p)=mp_take_fraction(mp, value(p),v);
+ return;
+ };
+ t=mp_type(q); q=dep_list(q); s=t;
+ if ( t==mp_dependent ) if ( v_is_scaled )
+ if (mp_ab_vs_cd(mp, mp_max_coef(mp,q),abs(v),coef_bound-1,unity)>=0 )
+ t=mp_proto_dependent;
+ q=mp_p_times_v(mp, q,v,s,t,v_is_scaled);
+ mp_dep_finish(mp, q,p,t);
+}
+
+@ Here is a routine that is similar to |times|; but it is invoked only
+internally, when |v| is a |fraction| whose magnitude is at most~1,
+and when |cur_type>=mp_color_type|.
+
+@c
+static void mp_frac_mult (MP mp,scaled n, scaled d) {
+ /* multiplies |cur_exp| by |n/d| */
+ pointer p; /* a pair node */
+ pointer old_exp; /* a capsule to recycle */
+ fraction v; /* |n/d| */
+ if ( mp->internal[mp_tracing_commands]>two ) {
+ @<Trace the fraction multiplication@>;
+ }
+ switch (mp->cur_type) {
+ case mp_transform_type:
+ case mp_color_type:
+ case mp_cmykcolor_type:
+ case mp_pair_type:
+ old_exp=mp_tarnished(mp, mp->cur_exp);
+ break;
+ case mp_independent: old_exp=mp_void; break;
+ default: old_exp=null; break;
+ }
+ if ( old_exp!=null ) {
+ old_exp=mp->cur_exp; mp_make_exp_copy(mp, old_exp);
+ }
+ v=mp_make_fraction(mp, n,d);
+ if ( mp->cur_type==mp_known ) {
+ mp->cur_exp=mp_take_fraction(mp, mp->cur_exp,v);
+ } else if ( mp->cur_type<=mp_pair_type ) {
+ p=value(mp->cur_exp)+mp->big_node_size[mp->cur_type];
+ do {
+ p=p-2;
+ mp_dep_mult(mp, p,v,false);
+ } while (p!=value(mp->cur_exp));
+ } else {
+ mp_dep_mult(mp, null,v,false);
+ }
+ if ( old_exp!=null ) {
+ mp_recycle_value(mp, old_exp);
+ mp_free_node(mp, old_exp,value_node_size);
+ }
+}
+
+@ @<Trace the fraction multiplication@>=
+{
+ mp_begin_diagnostic(mp);
+ mp_print_nl(mp, "{("); mp_print_scaled(mp,n); mp_print_char(mp,xord('/'));
+ mp_print_scaled(mp,d); mp_print(mp,")*("); mp_print_exp(mp,null,0);
+ mp_print(mp,")}");
+ mp_end_diagnostic(mp, false);
+}
+
+@ The |hard_times| routine multiplies a nice color or pair by a dependency list.
+
+@<Declare binary action procedures@>=
+static void mp_hard_times (MP mp,pointer p) {
+ pointer q; /* a copy of the dependent variable |p| */
+ pointer r; /* a component of the big node for the nice color or pair */
+ scaled v; /* the known value for |r| */
+ if ( mp_type(p)<=mp_pair_type ) {
+ q=mp_stash_cur_exp(mp); mp_unstash_cur_exp(mp, p); p=q;
+ }; /* now |cur_type=mp_pair_type| or |cur_type=mp_color_type| */
+ r=value(mp->cur_exp)+mp->big_node_size[mp->cur_type];
+ while (1) {
+ r=r-2;
+ v=value(r);
+ mp_type(r)=mp_type(p);
+ if ( r==value(mp->cur_exp) )
+ break;
+ mp_new_dep(mp, r,mp_copy_dep_list(mp, dep_list(p)));
+ mp_dep_mult(mp, r,v,true);
+ }
+ mp->mem[value_loc(r)]=mp->mem[value_loc(p)];
+ mp_link(prev_dep(p))=r;
+ mp_free_node(mp, p,value_node_size);
+ mp_dep_mult(mp, r,v,true);
+}
+
+@ @<Additional cases of binary operators@>=
+case over:
+ if ( (mp->cur_type!=mp_known)||(mp_type(p)<mp_color_type) ) {
+ mp_bad_binary(mp, p,over);
+ } else {
+ v=mp->cur_exp; mp_unstash_cur_exp(mp, p);
+ if ( v==0 ) {
+ @<Squeal about division by zero@>;
+ } else {
+ if ( mp->cur_type==mp_known ) {
+ mp->cur_exp=mp_make_scaled(mp, mp->cur_exp,v);
+ } else if ( mp->cur_type<=mp_pair_type ) {
+ p=value(mp->cur_exp)+mp->big_node_size[mp->cur_type];
+ do {
+ p=p-2; mp_dep_div(mp, p,v);
+ } while (p!=value(mp->cur_exp));
+ } else {
+ mp_dep_div(mp, null,v);
+ }
+ }
+ binary_return;
+ }
+ break;
+
+@ @<Declare binary action...@>=
+static void mp_dep_div (MP mp,pointer p, scaled v) {
+ pointer q; /* the dependency list being divided by |v| */
+ quarterword s,t; /* its type, before and after */
+ if ( p==null ) q=mp->cur_exp;
+ else if ( mp_type(p)!=mp_known ) q=p;
+ else { value(p)=mp_make_scaled(mp, value(p),v); return; };
+ t=mp_type(q); q=dep_list(q); s=t;
+ if ( t==mp_dependent )
+ if ( mp_ab_vs_cd(mp, mp_max_coef(mp,q),unity,coef_bound-1,abs(v))>=0 )
+ t=mp_proto_dependent;
+ q=mp_p_over_v(mp, q,v,s,t);
+ mp_dep_finish(mp, q,p,t);
+}
+
+@ @<Squeal about division by zero@>=
+{
+ exp_err("Division by zero");
+@.Division by zero@>
+ help2("You're trying to divide the quantity shown above the error",
+ "message by zero. I'm going to divide it by one instead.");
+ mp_put_get_error(mp);
+}
+
+@ @<Additional cases of binary operators@>=
+case pythag_add:
+case pythag_sub:
+ if ( (mp->cur_type==mp_known)&&(mp_type(p)==mp_known) ) {
+ if ( c==pythag_add ) mp->cur_exp=mp_pyth_add(mp, value(p),mp->cur_exp);
+ else mp->cur_exp=mp_pyth_sub(mp, value(p),mp->cur_exp);
+ } else mp_bad_binary(mp, p,c);
+ break;
+
+@ The next few sections of the program deal with affine transformations
+of coordinate data.
+
+@<Additional cases of binary operators@>=
+case rotated_by: case slanted_by:
+case scaled_by: case shifted_by: case transformed_by:
+case x_scaled: case y_scaled: case z_scaled:
+ if ( mp_type(p)==mp_path_type ) {
+ path_trans(c,p); binary_return;
+ } else if ( mp_type(p)==mp_pen_type ) {
+ pen_trans(c,p);
+ mp->cur_exp=mp_convex_hull(mp, mp->cur_exp);
+ /* rounding error could destroy convexity */
+ binary_return;
+ } else if ( (mp_type(p)==mp_pair_type)||(mp_type(p)==mp_transform_type) ) {
+ mp_big_trans(mp, p,c);
+ } else if ( mp_type(p)==mp_picture_type ) {
+ mp_do_edges_trans(mp, p,c); binary_return;
+ } else {
+ mp_bad_binary(mp, p,c);
+ }
+ break;
+
+@ Let |c| be one of the eight transform operators. The procedure call
+|set_up_trans(c)| first changes |cur_exp| to a transform that corresponds to
+|c| and the original value of |cur_exp|. (In particular, |cur_exp| doesn't
+change at all if |c=transformed_by|.)
+
+Then, if all components of the resulting transform are |known|, they are
+moved to the global variables |txx|, |txy|, |tyx|, |tyy|, |tx|, |ty|;
+and |cur_exp| is changed to the known value zero.
+
+@<Declare binary action...@>=
+static void mp_set_up_trans (MP mp,quarterword c) {
+ pointer p,q,r; /* list manipulation registers */
+ if ( (c!=transformed_by)||(mp->cur_type!=mp_transform_type) ) {
+ @<Put the current transform into |cur_exp|@>;
+ }
+ @<If the current transform is entirely known, stash it in global variables;
+ otherwise |return|@>;
+}
+
+@ @<Glob...@>=
+scaled txx;
+scaled txy;
+scaled tyx;
+scaled tyy;
+scaled tx;
+scaled ty; /* current transform coefficients */
+
+@ @<Put the current transform...@>=
+{
+ p=mp_stash_cur_exp(mp);
+ mp->cur_exp=mp_id_transform(mp);
+ mp->cur_type=mp_transform_type;
+ q=value(mp->cur_exp);
+ switch (c) {
+ @<For each of the eight cases, change the relevant fields of |cur_exp|
+ and |goto done|;
+ but do nothing if capsule |p| doesn't have the appropriate type@>;
+ }; /* there are no other cases */
+ mp_disp_err(mp, p,"Improper transformation argument");
+@.Improper transformation argument@>
+ help3("The expression shown above has the wrong type,",
+ "so I can\'t transform anything using it.",
+ "Proceed, and I'll omit the transformation.");
+ mp_put_get_error(mp);
+DONE:
+ mp_recycle_value(mp, p);
+ mp_free_node(mp, p,value_node_size);
+}
+
+@ @<If the current transform is entirely known, ...@>=
+q=value(mp->cur_exp); r=q+transform_node_size;
+do {
+ r=r-2;
+ if ( mp_type(r)!=mp_known ) return;
+} while (r!=q);
+mp->txx=value(xx_part_loc(q));
+mp->txy=value(xy_part_loc(q));
+mp->tyx=value(yx_part_loc(q));
+mp->tyy=value(yy_part_loc(q));
+mp->tx=value(x_part_loc(q));
+mp->ty=value(y_part_loc(q));
+mp_flush_cur_exp(mp, 0)
+
+@ @<For each of the eight cases...@>=
+case rotated_by:
+ if ( mp_type(p)==mp_known )
+ @<Install sines and cosines, then |goto done|@>;
+ break;
+case slanted_by:
+ if ( mp_type(p)>mp_pair_type ) {
+ mp_install(mp, xy_part_loc(q),p); goto DONE;
+ };
+ break;
+case scaled_by:
+ if ( mp_type(p)>mp_pair_type ) {
+ mp_install(mp, xx_part_loc(q),p); mp_install(mp, yy_part_loc(q),p);
+ goto DONE;
+ };
+ break;
+case shifted_by:
+ if ( mp_type(p)==mp_pair_type ) {
+ r=value(p); mp_install(mp, x_part_loc(q),x_part_loc(r));
+ mp_install(mp, y_part_loc(q),y_part_loc(r)); goto DONE;
+ };
+ break;
+case x_scaled:
+ if ( mp_type(p)>mp_pair_type ) {
+ mp_install(mp, xx_part_loc(q),p); goto DONE;
+ };
+ break;
+case y_scaled:
+ if ( mp_type(p)>mp_pair_type ) {
+ mp_install(mp, yy_part_loc(q),p); goto DONE;
+ };
+ break;
+case z_scaled:
+ if ( mp_type(p)==mp_pair_type )
+ @<Install a complex multiplier, then |goto done|@>;
+ break;
+case transformed_by:
+ break;
+
+
+@ @<Install sines and cosines, then |goto done|@>=
+{ mp_n_sin_cos(mp, (value(p) % three_sixty_units)*16);
+ value(xx_part_loc(q))=mp_round_fraction(mp, mp->n_cos);
+ value(yx_part_loc(q))=mp_round_fraction(mp, mp->n_sin);
+ value(xy_part_loc(q))=-value(yx_part_loc(q));
+ value(yy_part_loc(q))=value(xx_part_loc(q));
+ goto DONE;
+}
+
+@ @<Install a complex multiplier, then |goto done|@>=
+{
+ r=value(p);
+ mp_install(mp, xx_part_loc(q),x_part_loc(r));
+ mp_install(mp, yy_part_loc(q),x_part_loc(r));
+ mp_install(mp, yx_part_loc(q),y_part_loc(r));
+ if ( mp_type(y_part_loc(r))==mp_known ) negate(value(y_part_loc(r)));
+ else mp_negate_dep_list(mp, dep_list(y_part_loc(r)));
+ mp_install(mp, xy_part_loc(q),y_part_loc(r));
+ goto DONE;
+}
+
+@ Procedure |set_up_known_trans| is like |set_up_trans|, but it
+insists that the transformation be entirely known.
+
+@<Declare binary action...@>=
+static void mp_set_up_known_trans (MP mp,quarterword c) {
+ mp_set_up_trans(mp, c);
+ if ( mp->cur_type!=mp_known ) {
+ exp_err("Transform components aren't all known");
+@.Transform components...@>
+ help3("I'm unable to apply a partially specified transformation",
+ "except to a fully known pair or transform.",
+ "Proceed, and I'll omit the transformation.");
+ mp_put_get_flush_error(mp, 0);
+ mp->txx=unity; mp->txy=0; mp->tyx=0; mp->tyy=unity;
+ mp->tx=0; mp->ty=0;
+ }
+}
+
+@ Here's a procedure that applies the transform |txx..ty| to a pair of
+coordinates in locations |p| and~|q|.
+
+@<Declare binary action...@>=
+static void mp_trans (MP mp,pointer p, pointer q) {
+ scaled v; /* the new |x| value */
+ v=mp_take_scaled(mp, mp->mem[p].sc,mp->txx)+
+ mp_take_scaled(mp, mp->mem[q].sc,mp->txy)+mp->tx;
+ mp->mem[q].sc=mp_take_scaled(mp, mp->mem[p].sc,mp->tyx)+
+ mp_take_scaled(mp, mp->mem[q].sc,mp->tyy)+mp->ty;
+ mp->mem[p].sc=v;
+}
+
+@ The simplest transformation procedure applies a transform to all
+coordinates of a path. The |path_trans(c)(p)| macro applies
+a transformation defined by |cur_exp| and the transform operator |c|
+to the path~|p|.
+
+@d path_trans(A,B) { mp_set_up_known_trans(mp, (A));
+ mp_unstash_cur_exp(mp, (B));
+ mp_do_path_trans(mp, mp->cur_exp); }
+
+@<Declare binary action...@>=
+static void mp_do_path_trans (MP mp,pointer p) {
+ pointer q; /* list traverser */
+ q=p;
+ do {
+ if ( mp_left_type(q)!=mp_endpoint )
+ mp_trans(mp, q+3,q+4); /* that's |mp_left_x| and |mp_left_y| */
+ mp_trans(mp, q+1,q+2); /* that's |mp_x_coord| and |mp_y_coord| */
+ if ( mp_right_type(q)!=mp_endpoint )
+ mp_trans(mp, q+5,q+6); /* that's |mp_right_x| and |mp_right_y| */
+@^data structure assumptions@>
+ q=mp_link(q);
+ } while (q!=p);
+}
+
+@ Transforming a pen is very similar, except that there are no |mp_left_type|
+and |mp_right_type| fields.
+
+@d pen_trans(A,B) { mp_set_up_known_trans(mp, (A));
+ mp_unstash_cur_exp(mp, (B));
+ mp_do_pen_trans(mp, mp->cur_exp); }
+
+@<Declare binary action...@>=
+static void mp_do_pen_trans (MP mp,pointer p) {
+ pointer q; /* list traverser */
+ if ( pen_is_elliptical(p) ) {
+ mp_trans(mp, p+3,p+4); /* that's |mp_left_x| and |mp_left_y| */
+ mp_trans(mp, p+5,p+6); /* that's |mp_right_x| and |mp_right_y| */
+ };
+ q=p;
+ do {
+ mp_trans(mp, q+1,q+2); /* that's |mp_x_coord| and |mp_y_coord| */
+@^data structure assumptions@>
+ q=mp_link(q);
+ } while (q!=p);
+}
+
+@ The next transformation procedure applies to edge structures. It will do
+any transformation, but the results may be substandard if the picture contains
+text that uses downloaded bitmap fonts. The binary action procedure is
+|do_edges_trans|, but we also need a function that just scales a picture.
+That routine is |scale_edges|. Both it and the underlying routine |edges_trans|
+should be thought of as procedures that update an edge structure |h|, except
+that they have to return a (possibly new) structure because of the need to call
+|private_edges|.
+
+@<Declare binary action...@>=
+static pointer mp_edges_trans (MP mp, pointer h) {
+ pointer q; /* the object being transformed */
+ pointer r,s; /* for list manipulation */
+ scaled sx,sy; /* saved transformation parameters */
+ scaled sqdet; /* square root of determinant for |dash_scale| */
+ integer sgndet; /* sign of the determinant */
+ scaled v; /* a temporary value */
+ h=mp_private_edges(mp, h);
+ sqdet=mp_sqrt_det(mp, mp->txx,mp->txy,mp->tyx,mp->tyy);
+ sgndet=mp_ab_vs_cd(mp, mp->txx,mp->tyy,mp->txy,mp->tyx);
+ if ( dash_list(h)!=null_dash ) {
+ @<Try to transform the dash list of |h|@>;
+ }
+ @<Make the bounding box of |h| unknown if it can't be updated properly
+ without scanning the whole structure@>;
+ q=mp_link(dummy_loc(h));
+ while ( q!=null ) {
+ @<Transform graphical object |q|@>;
+ q=mp_link(q);
+ }
+ return h;
+}
+static void mp_do_edges_trans (MP mp,pointer p, quarterword c) {
+ mp_set_up_known_trans(mp, c);
+ value(p)=mp_edges_trans(mp, value(p));
+ mp_unstash_cur_exp(mp, p);
+}
+static void mp_scale_edges (MP mp) {
+ mp->txx=mp->se_sf; mp->tyy=mp->se_sf;
+ mp->txy=0; mp->tyx=0; mp->tx=0; mp->ty=0;
+ mp->se_pic=mp_edges_trans(mp, mp->se_pic);
+}
+
+@ @<Try to transform the dash list of |h|@>=
+if ( (mp->txy!=0)||(mp->tyx!=0)||
+ (mp->ty!=0)||(abs(mp->txx)!=abs(mp->tyy))) {
+ mp_flush_dash_list(mp, h);
+} else {
+ if ( mp->txx<0 ) { @<Reverse the dash list of |h|@>; }
+ @<Scale the dash list by |txx| and shift it by |tx|@>;
+ dash_y(h)=mp_take_scaled(mp, dash_y(h),abs(mp->tyy));
+}
+
+@ @<Reverse the dash list of |h|@>=
+{
+ r=dash_list(h);
+ dash_list(h)=null_dash;
+ while ( r!=null_dash ) {
+ s=r; r=mp_link(r);
+ v=start_x(s); start_x(s)=stop_x(s); stop_x(s)=v;
+ mp_link(s)=dash_list(h);
+ dash_list(h)=s;
+ }
+}
+
+@ @<Scale the dash list by |txx| and shift it by |tx|@>=
+r=dash_list(h);
+while ( r!=null_dash ) {
+ start_x(r)=mp_take_scaled(mp, start_x(r),mp->txx)+mp->tx;
+ stop_x(r)=mp_take_scaled(mp, stop_x(r),mp->txx)+mp->tx;
+ r=mp_link(r);
+}
+
+@ @<Make the bounding box of |h| unknown if it can't be updated properly...@>=
+if ( (mp->txx==0)&&(mp->tyy==0) ) {
+ @<Swap the $x$ and $y$ parameters in the bounding box of |h|@>;
+} else if ( (mp->txy!=0)||(mp->tyx!=0) ) {
+ mp_init_bbox(mp, h);
+ goto DONE1;
+}
+if ( minx_val(h)<=maxx_val(h) ) {
+ @<Scale the bounding box by |txx+txy| and |tyx+tyy|; then shift by
+ |(tx,ty)|@>;
+}
+DONE1:
+
+
+
+@ @<Swap the $x$ and $y$ parameters in the bounding box of |h|@>=
+{
+ v=minx_val(h); minx_val(h)=miny_val(h); miny_val(h)=v;
+ v=maxx_val(h); maxx_val(h)=maxy_val(h); maxy_val(h)=v;
+}
+
+@ The sum ``|txx+txy|'' is whichever of |txx| or |txy| is nonzero. The other
+sum is similar.
+
+@<Scale the bounding box by |txx+txy| and |tyx+tyy|; then shift...@>=
+{
+ minx_val(h)=mp_take_scaled(mp, minx_val(h),mp->txx+mp->txy)+mp->tx;
+ maxx_val(h)=mp_take_scaled(mp, maxx_val(h),mp->txx+mp->txy)+mp->tx;
+ miny_val(h)=mp_take_scaled(mp, miny_val(h),mp->tyx+mp->tyy)+mp->ty;
+ maxy_val(h)=mp_take_scaled(mp, maxy_val(h),mp->tyx+mp->tyy)+mp->ty;
+ if ( mp->txx+mp->txy<0 ) {
+ v=minx_val(h); minx_val(h)=maxx_val(h); maxx_val(h)=v;
+ }
+ if ( mp->tyx+mp->tyy<0 ) {
+ v=miny_val(h); miny_val(h)=maxy_val(h); maxy_val(h)=v;
+ }
+}
+
+@ Now we ready for the main task of transforming the graphical objects in edge
+structure~|h|.
+
+@<Transform graphical object |q|@>=
+switch (mp_type(q)) {
+case mp_fill_code: case mp_stroked_code:
+ mp_do_path_trans(mp, mp_path_p(q));
+ @<Transform |mp_pen_p(q)|, making sure polygonal pens stay counter-clockwise@>;
+ break;
+case mp_start_clip_code: case mp_start_bounds_code:
+ mp_do_path_trans(mp, mp_path_p(q));
+ break;
+case mp_text_code:
+ r=text_tx_loc(q);
+ @<Transform the compact transformation starting at |r|@>;
+ break;
+case mp_stop_clip_code: case mp_stop_bounds_code:
+ break;
+} /* there are no other cases */
+
+@ Note that the shift parameters |(tx,ty)| apply only to the path being stroked.
+The |dash_scale| has to be adjusted to scale the dash lengths in |mp_dash_p(q)|
+since the \ps\ output procedures will try to compensate for the transformation
+we are applying to |mp_pen_p(q)|. Since this compensation is based on the square
+root of the determinant, |sqdet| is the appropriate factor.
+
+@<Transform |mp_pen_p(q)|, making sure...@>=
+if ( mp_pen_p(q)!=null ) {
+ sx=mp->tx; sy=mp->ty;
+ mp->tx=0; mp->ty=0;
+ mp_do_pen_trans(mp, mp_pen_p(q));
+ if ( ((mp_type(q)==mp_stroked_code)&&(mp_dash_p(q)!=null)) )
+ dash_scale(q)=mp_take_scaled(mp, dash_scale(q),sqdet);
+ if ( ! pen_is_elliptical(mp_pen_p(q)) )
+ if ( sgndet<0 )
+ mp_pen_p(q)=mp_make_pen(mp, mp_copy_path(mp, mp_pen_p(q)),true);
+ /* this unreverses the pen */
+ mp->tx=sx; mp->ty=sy;
+}
+
+@ This uses the fact that transformations are stored in the order
+|(tx,ty,txx,txy,tyx,tyy)|.
+@^data structure assumptions@>
+
+@<Transform the compact transformation starting at |r|@>=
+mp_trans(mp, r,r+1);
+sx=mp->tx; sy=mp->ty;
+mp->tx=0; mp->ty=0;
+mp_trans(mp, r+2,r+4);
+mp_trans(mp, r+3,r+5);
+mp->tx=sx; mp->ty=sy
+
+@ The hard cases of transformation occur when big nodes are involved,
+and when some of their components are unknown.
+
+@<Declare binary action...@>=
+@<Declare subroutines needed by |big_trans|@>
+static void mp_big_trans (MP mp,pointer p, quarterword c) {
+ pointer q,r,pp,qq; /* list manipulation registers */
+ quarterword s; /* size of a big node */
+ s=mp->big_node_size[mp_type(p)]; q=value(p); r=q+s;
+ do {
+ r=r-2;
+ if ( mp_type(r)!=mp_known ) {
+ @<Transform an unknown big node and |return|@>;
+ }
+ } while (r!=q);
+ @<Transform a known big node@>;
+} /* node |p| will now be recycled by |do_binary| */
+
+@ @<Transform an unknown big node and |return|@>=
+{
+ mp_set_up_known_trans(mp, c); mp_make_exp_copy(mp, p);
+ r=value(mp->cur_exp);
+ if ( mp->cur_type==mp_transform_type ) {
+ mp_bilin1(mp, yy_part_loc(r),mp->tyy,xy_part_loc(q),mp->tyx,0);
+ mp_bilin1(mp, yx_part_loc(r),mp->tyy,xx_part_loc(q),mp->tyx,0);
+ mp_bilin1(mp, xy_part_loc(r),mp->txx,yy_part_loc(q),mp->txy,0);
+ mp_bilin1(mp, xx_part_loc(r),mp->txx,yx_part_loc(q),mp->txy,0);
+ }
+ mp_bilin1(mp, y_part_loc(r),mp->tyy,x_part_loc(q),mp->tyx,mp->ty);
+ mp_bilin1(mp, x_part_loc(r),mp->txx,y_part_loc(q),mp->txy,mp->tx);
+ return;
+}
+
+@ Let |p| point to a two-word value field inside a big node of |cur_exp|,
+and let |q| point to a another value field. The |bilin1| procedure
+replaces |p| by $p\cdot t+q\cdot u+\delta$.
+
+@<Declare subroutines needed by |big_trans|@>=
+static void mp_bilin1 (MP mp, pointer p, scaled t, pointer q,
+ scaled u, scaled delta) {
+ pointer r; /* list traverser */
+ if ( t!=unity ) mp_dep_mult(mp, p,t,true);
+ if ( u!=0 ) {
+ if ( mp_type(q)==mp_known ) {
+ delta+=mp_take_scaled(mp, value(q),u);
+ } else {
+ @<Ensure that |type(p)=mp_proto_dependent|@>;
+ dep_list(p)=mp_p_plus_fq(mp, dep_list(p),u,dep_list(q),
+ mp_proto_dependent,mp_type(q));
+ }
+ }
+ if ( mp_type(p)==mp_known ) {
+ value(p)+=delta;
+ } else {
+ r=dep_list(p);
+ while ( mp_info(r)!=null ) r=mp_link(r);
+ delta+=value(r);
+ if ( r!=dep_list(p) ) value(r)=delta;
+ else { mp_recycle_value(mp, p); mp_type(p)=mp_known; value(p)=delta; };
+ }
+ if ( mp->fix_needed ) mp_fix_dependencies(mp);
+}
+
+@ @<Ensure that |type(p)=mp_proto_dependent|@>=
+if ( mp_type(p)!=mp_proto_dependent ) {
+ if ( mp_type(p)==mp_known )
+ mp_new_dep(mp, p,mp_const_dependency(mp, value(p)));
+ else
+ dep_list(p)=mp_p_times_v(mp, dep_list(p),unity,mp_dependent,
+ mp_proto_dependent,true);
+ mp_type(p)=mp_proto_dependent;
+}
+
+@ @<Transform a known big node@>=
+mp_set_up_trans(mp, c);
+if ( mp->cur_type==mp_known ) {
+ @<Transform known by known@>;
+} else {
+ pp=mp_stash_cur_exp(mp); qq=value(pp);
+ mp_make_exp_copy(mp, p); r=value(mp->cur_exp);
+ if ( mp->cur_type==mp_transform_type ) {
+ mp_bilin2(mp, yy_part_loc(r),yy_part_loc(qq),
+ value(xy_part_loc(q)),yx_part_loc(qq),null);
+ mp_bilin2(mp, yx_part_loc(r),yy_part_loc(qq),
+ value(xx_part_loc(q)),yx_part_loc(qq),null);
+ mp_bilin2(mp, xy_part_loc(r),xx_part_loc(qq),
+ value(yy_part_loc(q)),xy_part_loc(qq),null);
+ mp_bilin2(mp, xx_part_loc(r),xx_part_loc(qq),
+ value(yx_part_loc(q)),xy_part_loc(qq),null);
+ };
+ mp_bilin2(mp, y_part_loc(r),yy_part_loc(qq),
+ value(x_part_loc(q)),yx_part_loc(qq),y_part_loc(qq));
+ mp_bilin2(mp, x_part_loc(r),xx_part_loc(qq),
+ value(y_part_loc(q)),xy_part_loc(qq),x_part_loc(qq));
+ mp_recycle_value(mp, pp); mp_free_node(mp, pp,value_node_size);
+}
+
+@ Let |p| be a |mp_proto_dependent| value whose dependency list ends
+at |dep_final|. The following procedure adds |v| times another
+numeric quantity to~|p|.
+
+@<Declare subroutines needed by |big_trans|@>=
+static void mp_add_mult_dep (MP mp,pointer p, scaled v, pointer r) {
+ if ( mp_type(r)==mp_known ) {
+ value(mp->dep_final)+=mp_take_scaled(mp, value(r),v);
+ } else {
+ dep_list(p)=mp_p_plus_fq(mp, dep_list(p),v,dep_list(r),
+ mp_proto_dependent,mp_type(r));
+ if ( mp->fix_needed ) mp_fix_dependencies(mp);
+ }
+}
+
+@ The |bilin2| procedure is something like |bilin1|, but with known
+and unknown quantities reversed. Parameter |p| points to a value field
+within the big node for |cur_exp|; and |type(p)=mp_known|. Parameters
+|t| and~|u| point to value fields elsewhere; so does parameter~|q|,
+unless it is |null| (which stands for zero). Location~|p| will be
+replaced by $p\cdot t+v\cdot u+q$.
+
+@<Declare subroutines needed by |big_trans|@>=
+static void mp_bilin2 (MP mp,pointer p, pointer t, scaled v,
+ pointer u, pointer q) {
+ scaled vv; /* temporary storage for |value(p)| */
+ vv=value(p); mp_type(p)=mp_proto_dependent;
+ mp_new_dep(mp, p,mp_const_dependency(mp, 0)); /* this sets |dep_final| */
+ if ( vv!=0 )
+ mp_add_mult_dep(mp, p,vv,t); /* |dep_final| doesn't change */
+ if ( v!=0 ) mp_add_mult_dep(mp, p,v,u);
+ if ( q!=null ) mp_add_mult_dep(mp, p,unity,q);
+ if ( dep_list(p)==mp->dep_final ) {
+ vv=value(mp->dep_final); mp_recycle_value(mp, p);
+ mp_type(p)=mp_known; value(p)=vv;
+ }
+}
+
+@ @<Transform known by known@>=
+{
+ mp_make_exp_copy(mp, p); r=value(mp->cur_exp);
+ if ( mp->cur_type==mp_transform_type ) {
+ mp_bilin3(mp, yy_part_loc(r),mp->tyy,value(xy_part_loc(q)),mp->tyx,0);
+ mp_bilin3(mp, yx_part_loc(r),mp->tyy,value(xx_part_loc(q)),mp->tyx,0);
+ mp_bilin3(mp, xy_part_loc(r),mp->txx,value(yy_part_loc(q)),mp->txy,0);
+ mp_bilin3(mp, xx_part_loc(r),mp->txx,value(yx_part_loc(q)),mp->txy,0);
+ }
+ mp_bilin3(mp, y_part_loc(r),mp->tyy,value(x_part_loc(q)),mp->tyx,mp->ty);
+ mp_bilin3(mp, x_part_loc(r),mp->txx,value(y_part_loc(q)),mp->txy,mp->tx);
+}
+
+@ Finally, in |bilin3| everything is |known|.
+
+@<Declare subroutines needed by |big_trans|@>=
+static void mp_bilin3 (MP mp,pointer p, scaled t,
+ scaled v, scaled u, scaled delta) {
+ if ( t!=unity )
+ delta+=mp_take_scaled(mp, value(p),t);
+ else
+ delta+=value(p);
+ if ( u!=0 ) value(p)=delta+mp_take_scaled(mp, v,u);
+ else value(p)=delta;
+}
+
+@ @<Additional cases of binary operators@>=
+case concatenate:
+ if ( (mp->cur_type==mp_string_type)&&(mp_type(p)==mp_string_type) ) mp_cat(mp, p);
+ else mp_bad_binary(mp, p,concatenate);
+ break;
+case substring_of:
+ if ( mp_nice_pair(mp, p,mp_type(p))&&(mp->cur_type==mp_string_type) )
+ mp_chop_string(mp, value(p));
+ else mp_bad_binary(mp, p,substring_of);
+ break;
+case subpath_of:
+ if ( mp->cur_type==mp_pair_type ) mp_pair_to_path(mp);
+ if ( mp_nice_pair(mp, p,mp_type(p))&&(mp->cur_type==mp_path_type) )
+ mp_chop_path(mp, value(p));
+ else mp_bad_binary(mp, p,subpath_of);
+ break;
+
+@ @<Declare binary action...@>=
+static void mp_cat (MP mp,pointer p) {
+ str_number a,b; /* the strings being concatenated */
+ integer k; /* run length */
+ integer needed;
+ a=value(p); b=mp->cur_exp; k=length(a);
+ needed=mp->pool_ptr+k+length(b);
+ /* this will free some memory, hopefully */
+ if (mp->pool_ptr>(11*mp->old_pool_size)/10) {
+ mp->old_pool_size = mp->pool_ptr;
+ mp_do_compaction(mp, mp->pool_size);
+ }
+ if ( needed > mp->max_pool_ptr ) {
+ if ( needed > mp->pool_size ) {
+ mp_reallocate_pool(mp,needed);
+ }
+ mp->max_pool_ptr=needed;
+ }
+ memcpy(mp->str_pool+mp->pool_ptr, mp->str_pool+mp->str_start[a],(size_t)k);
+ mp->pool_ptr+=k;
+ k=length(b);
+ memcpy(mp->str_pool+mp->pool_ptr, mp->str_pool+mp->str_start[b],(size_t)k);
+ mp->pool_ptr+=k;
+ mp->cur_exp=mp_make_string(mp); delete_str_ref(b);
+}
+
+@ @<Declare binary action...@>=
+static void mp_chop_string (MP mp,pointer p) {
+ integer a, b; /* start and stop points */
+ integer l; /* length of the original string */
+ integer k; /* runs from |a| to |b| */
+ str_number s; /* the original string */
+ boolean reversed; /* was |a>b|? */
+ a=mp_round_unscaled(mp, value(x_part_loc(p)));
+ b=mp_round_unscaled(mp, value(y_part_loc(p)));
+ if ( a<=b ) reversed=false;
+ else { reversed=true; k=a; a=b; b=k; };
+ s=mp->cur_exp; l=length(s);
+ if ( a<0 ) {
+ a=0;
+ if ( b<0 ) b=0;
+ }
+ if ( b>l ) {
+ b=l;
+ if ( a>l ) a=l;
+ }
+ str_room(b-a);
+ if ( reversed ) {
+ for (k=mp->str_start[s]+b-1;k>=mp->str_start[s]+a;k--) {
+ append_char(mp->str_pool[k]);
+ }
+ } else {
+ for (k=mp->str_start[s]+a;k<mp->str_start[s]+b;k++) {
+ append_char(mp->str_pool[k]);
+ }
+ }
+ mp->cur_exp=mp_make_string(mp); delete_str_ref(s);
+}
+
+@ @<Declare binary action...@>=
+static void mp_chop_path (MP mp,pointer p) {
+ pointer q; /* a knot in the original path */
+ pointer pp,qq,rr,ss; /* link variables for copies of path nodes */
+ scaled a,b,k,l; /* indices for chopping */
+ boolean reversed; /* was |a>b|? */
+ l=mp_path_length(mp); a=value(x_part_loc(p)); b=value(y_part_loc(p));
+ if ( a<=b ) reversed=false;
+ else { reversed=true; k=a; a=b; b=k; };
+ @<Dispense with the cases |a<0| and/or |b>l|@>;
+ q=mp->cur_exp;
+ while ( a>=unity ) {
+ q=mp_link(q); a=a-unity; b=b-unity;
+ }
+ if ( b==a ) {
+ @<Construct a path from |pp| to |qq| of length zero@>;
+ } else {
+ @<Construct a path from |pp| to |qq| of length $\lceil b\rceil$@>;
+ }
+ mp_left_type(pp)=mp_endpoint; mp_right_type(qq)=mp_endpoint; mp_link(qq)=pp;
+ mp_toss_knot_list(mp, mp->cur_exp);
+ if ( reversed ) {
+ mp->cur_exp=mp_link(mp_htap_ypoc(mp, pp)); mp_toss_knot_list(mp, pp);
+ } else {
+ mp->cur_exp=pp;
+ }
+}
+
+@ @<Dispense with the cases |a<0| and/or |b>l|@>=
+if ( a<0 ) {
+ if ( mp_left_type(mp->cur_exp)==mp_endpoint ) {
+ a=0; if ( b<0 ) b=0;
+ } else {
+ do { a=a+l; b=b+l; } while (a<0); /* a cycle always has length |l>0| */
+ }
+}
+if ( b>l ) {
+ if ( mp_left_type(mp->cur_exp)==mp_endpoint ) {
+ b=l; if ( a>l ) a=l;
+ } else {
+ while ( a>=l ) {
+ a=a-l; b=b-l;
+ }
+ }
+}
+
+@ @<Construct a path from |pp| to |qq| of length $\lceil b\rceil$@>=
+{
+ pp=mp_copy_knot(mp, q); qq=pp;
+ do {
+ q=mp_link(q); rr=qq; qq=mp_copy_knot(mp, q); mp_link(rr)=qq; b=b-unity;
+ } while (b>0);
+ if ( a>0 ) {
+ ss=pp; pp=mp_link(pp);
+ mp_split_cubic(mp, ss,a*010000); pp=mp_link(ss);
+ mp_free_node(mp, ss,knot_node_size);
+ if ( rr==ss ) {
+ b=mp_make_scaled(mp, b,unity-a); rr=pp;
+ }
+ }
+ if ( b<0 ) {
+ mp_split_cubic(mp, rr,(b+unity)*010000);
+ mp_free_node(mp, qq,knot_node_size);
+ qq=mp_link(rr);
+ }
+}
+
+@ @<Construct a path from |pp| to |qq| of length zero@>=
+{
+ if ( a>0 ) { mp_split_cubic(mp, q,a*010000); q=mp_link(q); };
+ pp=mp_copy_knot(mp, q); qq=pp;
+}
+
+@ @<Additional cases of binary operators@>=
+case point_of: case precontrol_of: case postcontrol_of:
+ if ( mp->cur_type==mp_pair_type )
+ mp_pair_to_path(mp);
+ if ( (mp->cur_type==mp_path_type)&&(mp_type(p)==mp_known) )
+ mp_find_point(mp, value(p),c);
+ else
+ mp_bad_binary(mp, p,c);
+ break;
+case pen_offset_of:
+ if ( (mp->cur_type==mp_pen_type)&& mp_nice_pair(mp, p,mp_type(p)) )
+ mp_set_up_offset(mp, value(p));
+ else
+ mp_bad_binary(mp, p,pen_offset_of);
+ break;
+case direction_time_of:
+ if ( mp->cur_type==mp_pair_type ) mp_pair_to_path(mp);
+ if ( (mp->cur_type==mp_path_type)&& mp_nice_pair(mp, p,mp_type(p)) )
+ mp_set_up_direction_time(mp, value(p));
+ else
+ mp_bad_binary(mp, p,direction_time_of);
+ break;
+case envelope_of:
+ if ( (mp_type(p) != mp_pen_type) || (mp->cur_type != mp_path_type) )
+ mp_bad_binary(mp, p,envelope_of);
+ else
+ mp_set_up_envelope(mp, p);
+ break;
+
+@ @<Declare binary action...@>=
+static void mp_set_up_offset (MP mp,pointer p) {
+ mp_find_offset(mp, value(x_part_loc(p)),value(y_part_loc(p)),mp->cur_exp);
+ mp_pair_value(mp, mp->cur_x,mp->cur_y);
+}
+static void mp_set_up_direction_time (MP mp,pointer p) {
+ mp_flush_cur_exp(mp, mp_find_direction_time(mp, value(x_part_loc(p)),
+ value(y_part_loc(p)),mp->cur_exp));
+}
+static void mp_set_up_envelope (MP mp,pointer p) {
+ quarterword ljoin, lcap;
+ scaled miterlim;
+ pointer q = mp_copy_path(mp, mp->cur_exp); /* the original path */
+ /* TODO: accept elliptical pens for straight paths */
+ if (pen_is_elliptical(value(p))) {
+ mp_bad_envelope_pen(mp);
+ mp->cur_exp = q;
+ mp->cur_type = mp_path_type;
+ return;
+ }
+ if ( mp->internal[mp_linejoin]>unity ) ljoin=2;
+ else if ( mp->internal[mp_linejoin]>0 ) ljoin=1;
+ else ljoin=0;
+ if ( mp->internal[mp_linecap]>unity ) lcap=2;
+ else if ( mp->internal[mp_linecap]>0 ) lcap=1;
+ else lcap=0;
+ if ( mp->internal[mp_miterlimit]<unity )
+ miterlim=unity;
+ else
+ miterlim=mp->internal[mp_miterlimit];
+ mp->cur_exp = mp_make_envelope(mp, q, value(p), ljoin,lcap,miterlim);
+ mp->cur_type = mp_path_type;
+}
+
+@ @<Declare binary action...@>=
+static void mp_find_point (MP mp,scaled v, quarterword c) {
+ pointer p; /* the path */
+ scaled n; /* its length */
+ p=mp->cur_exp;
+ if ( mp_left_type(p)==mp_endpoint ) n=-unity; else n=0;
+ do { p=mp_link(p); n=n+unity; } while (p!=mp->cur_exp);
+ if ( n==0 ) {
+ v=0;
+ } else if ( v<0 ) {
+ if ( mp_left_type(p)==mp_endpoint ) v=0;
+ else v=n-1-((-v-1) % n);
+ } else if ( v>n ) {
+ if ( mp_left_type(p)==mp_endpoint ) v=n;
+ else v=v % n;
+ }
+ p=mp->cur_exp;
+ while ( v>=unity ) { p=mp_link(p); v=v-unity; };
+ if ( v!=0 ) {
+ @<Insert a fractional node by splitting the cubic@>;
+ }
+ @<Set the current expression to the desired path coordinates@>;
+}
+
+@ @<Insert a fractional node...@>=
+{ mp_split_cubic(mp, p,v*010000); p=mp_link(p); }
+
+@ @<Set the current expression to the desired path coordinates...@>=
+switch (c) {
+case point_of:
+ mp_pair_value(mp, mp_x_coord(p),mp_y_coord(p));
+ break;
+case precontrol_of:
+ if ( mp_left_type(p)==mp_endpoint ) mp_pair_value(mp, mp_x_coord(p),mp_y_coord(p));
+ else mp_pair_value(mp, mp_left_x(p),mp_left_y(p));
+ break;
+case postcontrol_of:
+ if ( mp_right_type(p)==mp_endpoint ) mp_pair_value(mp, mp_x_coord(p),mp_y_coord(p));
+ else mp_pair_value(mp, mp_right_x(p),mp_right_y(p));
+ break;
+} /* there are no other cases */
+
+@ @<Additional cases of binary operators@>=
+case arc_time_of:
+ if ( mp->cur_type==mp_pair_type )
+ mp_pair_to_path(mp);
+ if ( (mp->cur_type==mp_path_type)&&(mp_type(p)==mp_known) )
+ mp_flush_cur_exp(mp, mp_get_arc_time(mp, mp->cur_exp,value(p)));
+ else
+ mp_bad_binary(mp, p,c);
+ break;
+
+@ @<Additional cases of bin...@>=
+case intersect:
+ if ( mp_type(p)==mp_pair_type ) {
+ q=mp_stash_cur_exp(mp); mp_unstash_cur_exp(mp, p);
+ mp_pair_to_path(mp); p=mp_stash_cur_exp(mp); mp_unstash_cur_exp(mp, q);
+ };
+ if ( mp->cur_type==mp_pair_type ) mp_pair_to_path(mp);
+ if ( (mp->cur_type==mp_path_type)&&(mp_type(p)==mp_path_type) ) {
+ mp_path_intersection(mp, value(p),mp->cur_exp);
+ mp_pair_value(mp, mp->cur_t,mp->cur_tt);
+ } else {
+ mp_bad_binary(mp, p,intersect);
+ }
+ break;
+
+@ @<Additional cases of bin...@>=
+case in_font:
+ if ( (mp->cur_type!=mp_string_type)||(mp_type(p)!=mp_string_type))
+ mp_bad_binary(mp, p,in_font);
+ else { mp_do_infont(mp, p); binary_return; }
+ break;
+
+@ Function |new_text_node| owns the reference count for its second argument
+(the text string) but not its first (the font name).
+
+@<Declare binary action...@>=
+static void mp_do_infont (MP mp,pointer p) {
+ pointer q;
+ q=mp_get_node(mp, edge_header_size);
+ mp_init_edges(mp, q);
+ mp_link(obj_tail(q))=mp_new_text_node(mp,str(mp->cur_exp),value(p));
+ obj_tail(q)=mp_link(obj_tail(q));
+ mp_free_node(mp, p,value_node_size);
+ mp_flush_cur_exp(mp, q);
+ mp->cur_type=mp_picture_type;
+}
+
+@* \[40] Statements and commands.
+The chief executive of \MP\ is the |do_statement| routine, which
+contains the master switch that causes all the various pieces of \MP\
+to do their things, in the right order.
+
+In a sense, this is the grand climax of the program: It applies all the
+tools that we have worked so hard to construct. In another sense, this is
+the messiest part of the program: It necessarily refers to other pieces
+of code all over the place, so that a person can't fully understand what is
+going on without paging back and forth to be reminded of conventions that
+are defined elsewhere. We are now at the hub of the web.
+
+The structure of |do_statement| itself is quite simple. The first token
+of the statement is fetched using |get_x_next|. If it can be the first
+token of an expression, we look for an equation, an assignment, or a
+title. Otherwise we use a \&{case} construction to branch at high speed to
+the appropriate routine for various and sundry other types of commands,
+each of which has an ``action procedure'' that does the necessary work.
+
+The program uses the fact that
+$$\hbox{|min_primary_command=max_statement_command=type_name|}$$
+to interpret a statement that starts with, e.g., `\&{string}',
+as a type declaration rather than a boolean expression.
+
+@c void mp_do_statement (MP mp) { /* governs \MP's activities */
+ mp->cur_type=mp_vacuous; mp_get_x_next(mp);
+ if ( mp->cur_cmd>max_primary_command ) {
+ @<Worry about bad statement@>;
+ } else if ( mp->cur_cmd>max_statement_command ) {
+ @<Do an equation, assignment, title, or
+ `$\langle\,$expression$\,\rangle\,$\&{endgroup}'@>;
+ } else {
+ @<Do a statement that doesn't begin with an expression@>;
+ }
+ if ( mp->cur_cmd<semicolon )
+ @<Flush unparsable junk that was found after the statement@>;
+ mp->error_count=0;
+}
+
+@ @<Declarations@>=
+@<Declare action procedures for use by |do_statement|@>
+
+@ The only command codes |>max_primary_command| that can be present
+at the beginning of a statement are |semicolon| and higher; these
+occur when the statement is null.
+
+@<Worry about bad statement@>=
+{
+ if ( mp->cur_cmd<semicolon ) {
+ print_err("A statement can't begin with `");
+@.A statement can't begin with x@>
+ mp_print_cmd_mod(mp, mp->cur_cmd,mp->cur_mod); mp_print_char(mp, xord('\''));
+ help5("I was looking for the beginning of a new statement.",
+ "If you just proceed without changing anything, I'll ignore",
+ "everything up to the next `;'. Please insert a semicolon",
+ "now in front of anything that you don't want me to delete.",
+ "(See Chapter 27 of The METAFONTbook for an example.)");
+@:METAFONTbook}{\sl The {\logos METAFONT\/}book@>
+ mp_back_error(mp); mp_get_x_next(mp);
+ }
+}
+
+@ The help message printed here says that everything is flushed up to
+a semicolon, but actually the commands |end_group| and |stop| will
+also terminate a statement.
+
+@<Flush unparsable junk that was found after the statement@>=
+{
+ print_err("Extra tokens will be flushed");
+@.Extra tokens will be flushed@>
+ help6("I've just read as much of that statement as I could fathom,",
+ "so a semicolon should have been next. It's very puzzling...",
+ "but I'll try to get myself back together, by ignoring",
+ "everything up to the next `;'. Please insert a semicolon",
+ "now in front of anything that you don't want me to delete.",
+ "(See Chapter 27 of The METAFONTbook for an example.)");
+@:METAFONTbook}{\sl The {\logos METAFONT\/}book@>
+ mp_back_error(mp); mp->scanner_status=flushing;
+ do {
+ get_t_next;
+ @<Decrease the string reference count...@>;
+ } while (! end_of_statement); /* |cur_cmd=semicolon|, |end_group|, or |stop| */
+ mp->scanner_status=normal;
+}
+
+@ If |do_statement| ends with |cur_cmd=end_group|, we should have
+|cur_type=mp_vacuous| unless the statement was simply an expression;
+in the latter case, |cur_type| and |cur_exp| should represent that
+expression.
+
+@<Do a statement that doesn't...@>=
+{
+ if ( mp->internal[mp_tracing_commands]>0 )
+ show_cur_cmd_mod;
+ switch (mp->cur_cmd ) {
+ case type_name:mp_do_type_declaration(mp); break;
+ case macro_def:
+ if ( mp->cur_mod>var_def ) mp_make_op_def(mp);
+ else if ( mp->cur_mod>end_def ) mp_scan_def(mp);
+ break;
+ @<Cases of |do_statement| that invoke particular commands@>;
+ } /* there are no other cases */
+ mp->cur_type=mp_vacuous;
+}
+
+@ The most important statements begin with expressions.
+
+@<Do an equation, assignment, title, or...@>=
+{
+ mp->var_flag=assignment; mp_scan_expression(mp);
+ if ( mp->cur_cmd<end_group ) {
+ if ( mp->cur_cmd==equals ) mp_do_equation(mp);
+ else if ( mp->cur_cmd==assignment ) mp_do_assignment(mp);
+ else if ( mp->cur_type==mp_string_type ) {@<Do a title@> ; }
+ else if ( mp->cur_type!=mp_vacuous ){
+ exp_err("Isolated expression");
+@.Isolated expression@>
+ help3("I couldn't find an `=' or `:=' after the",
+ "expression that is shown above this error message,",
+ "so I guess I'll just ignore it and carry on.");
+ mp_put_get_error(mp);
+ }
+ mp_flush_cur_exp(mp, 0); mp->cur_type=mp_vacuous;
+ }
+}
+
+@ @<Do a title@>=
+{
+ if ( mp->internal[mp_tracing_titles]>0 ) {
+ mp_print_nl(mp, ""); mp_print_str(mp, mp->cur_exp); update_terminal;
+ }
+}
+
+@ Equations and assignments are performed by the pair of mutually recursive
+@^recursion@>
+routines |do_equation| and |do_assignment|. These routines are called when
+|cur_cmd=equals| and when |cur_cmd=assignment|, respectively; the left-hand
+side is in |cur_type| and |cur_exp|, while the right-hand side is yet
+to be scanned. After the routines are finished, |cur_type| and |cur_exp|
+will be equal to the right-hand side (which will normally be equal
+to the left-hand side).
+
+@<Declarations@>=
+@<Declare the procedure called |make_eq|@>
+static void mp_do_equation (MP mp) ;
+
+@ @c
+void mp_do_equation (MP mp) {
+ pointer lhs; /* capsule for the left-hand side */
+ pointer p; /* temporary register */
+ lhs=mp_stash_cur_exp(mp); mp_get_x_next(mp);
+ mp->var_flag=assignment; mp_scan_expression(mp);
+ if ( mp->cur_cmd==equals ) mp_do_equation(mp);
+ else if ( mp->cur_cmd==assignment ) mp_do_assignment(mp);
+ if ( mp->internal[mp_tracing_commands]>two )
+ @<Trace the current equation@>;
+ if ( mp->cur_type==mp_unknown_path ) if ( mp_type(lhs)==mp_pair_type ) {
+ p=mp_stash_cur_exp(mp); mp_unstash_cur_exp(mp, lhs); lhs=p;
+ }; /* in this case |make_eq| will change the pair to a path */
+ mp_make_eq(mp, lhs); /* equate |lhs| to |(cur_type,cur_exp)| */
+}
+
+@ And |do_assignment| is similar to |do_equation|:
+
+@<Declarations@>=
+static void mp_do_assignment (MP mp);
+
+@ @c
+void mp_do_assignment (MP mp) {
+ pointer lhs; /* token list for the left-hand side */
+ pointer p; /* where the left-hand value is stored */
+ pointer q; /* temporary capsule for the right-hand value */
+ if ( mp->cur_type!=mp_token_list ) {
+ exp_err("Improper `:=' will be changed to `='");
+@.Improper `:='@>
+ help2("I didn't find a variable name at the left of the `:=',",
+ "so I'm going to pretend that you said `=' instead.");
+ mp_error(mp); mp_do_equation(mp);
+ } else {
+ lhs=mp->cur_exp; mp->cur_type=mp_vacuous;
+ mp_get_x_next(mp); mp->var_flag=assignment; mp_scan_expression(mp);
+ if ( mp->cur_cmd==equals ) mp_do_equation(mp);
+ else if ( mp->cur_cmd==assignment ) mp_do_assignment(mp);
+ if ( mp->internal[mp_tracing_commands]>two )
+ @<Trace the current assignment@>;
+ if ( mp_info(lhs)>hash_end ) {
+ @<Assign the current expression to an internal variable@>;
+ } else {
+ @<Assign the current expression to the variable |lhs|@>;
+ }
+ mp_flush_node_list(mp, lhs);
+ }
+}
+
+@ @<Trace the current equation@>=
+{
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "{("); mp_print_exp(mp,lhs,0);
+ mp_print(mp,")=("); mp_print_exp(mp,null,0);
+ mp_print(mp,")}"); mp_end_diagnostic(mp, false);
+}
+
+@ @<Trace the current assignment@>=
+{
+ mp_begin_diagnostic(mp); mp_print_nl(mp, "{");
+ if ( mp_info(lhs)>hash_end )
+ mp_print(mp, mp->int_name[mp_info(lhs)-(hash_end)]);
+ else
+ mp_show_token_list(mp, lhs,null,1000,0);
+ mp_print(mp, ":="); mp_print_exp(mp, null,0);
+ mp_print_char(mp, xord('}')); mp_end_diagnostic(mp, false);
+}
+
+@ @<Assign the current expression to an internal variable@>=
+if ( mp->cur_type==mp_known || mp->cur_type==mp_string_type ) {
+ if (mp->cur_type==mp_string_type)
+ add_str_ref(mp->cur_exp);
+ mp->internal[mp_info(lhs)-(hash_end)]=mp->cur_exp;
+} else {
+ exp_err("Internal quantity `");
+@.Internal quantity...@>
+ mp_print(mp, mp->int_name[mp_info(lhs)-(hash_end)]);
+ mp_print(mp, "' must receive a known value");
+ help2("I can\'t set an internal quantity to anything but a known",
+ "numeric value, so I'll have to ignore this assignment.");
+ mp_put_get_error(mp);
+}
+
+@ @<Assign the current expression to the variable |lhs|@>=
+{
+ p=mp_find_variable(mp, lhs);
+ if ( p!=null ) {
+ q=mp_stash_cur_exp(mp); mp->cur_type=mp_und_type(mp, p);
+ mp_recycle_value(mp, p);
+ mp_type(p)=mp->cur_type; value(p)=null; mp_make_exp_copy(mp, p);
+ p=mp_stash_cur_exp(mp); mp_unstash_cur_exp(mp, q); mp_make_eq(mp, p);
+ } else {
+ mp_obliterated(mp, lhs); mp_put_get_error(mp);
+ }
+}
+
+
+@ And now we get to the nitty-gritty. The |make_eq| procedure is given
+a pointer to a capsule that is to be equated to the current expression.
+
+@<Declare the procedure called |make_eq|@>=
+static void mp_make_eq (MP mp,pointer lhs) ;
+
+
+@
+@c void mp_make_eq (MP mp,pointer lhs) {
+ quarterword t; /* type of the left-hand side */
+ pointer p,q; /* pointers inside of big nodes */
+ integer v=0; /* value of the left-hand side */
+RESTART:
+ t=mp_type(lhs);
+ if ( t<=mp_pair_type ) v=value(lhs);
+ switch (t) {
+ @<For each type |t|, make an equation and |goto done| unless |cur_type|
+ is incompatible with~|t|@>;
+ } /* all cases have been listed */
+ @<Announce that the equation cannot be performed@>;
+DONE:
+ check_arith; mp_recycle_value(mp, lhs);
+ mp_free_node(mp, lhs,value_node_size);
+}
+
+@ @<Announce that the equation cannot be performed@>=
+mp_disp_err(mp, lhs,"");
+exp_err("Equation cannot be performed (");
+@.Equation cannot be performed@>
+if ( mp_type(lhs)<=mp_pair_type ) mp_print_type(mp, mp_type(lhs));
+else mp_print(mp, "numeric");
+mp_print_char(mp, xord('='));
+if ( mp->cur_type<=mp_pair_type ) mp_print_type(mp, mp->cur_type);
+else mp_print(mp, "numeric");
+mp_print_char(mp, xord(')'));
+help2("I'm sorry, but I don't know how to make such things equal.",
+ "(See the two expressions just above the error message.)");
+mp_put_get_error(mp)
+
+@ @<For each type |t|, make an equation and |goto done| unless...@>=
+case mp_boolean_type: case mp_string_type: case mp_pen_type:
+case mp_path_type: case mp_picture_type:
+ if ( mp->cur_type==t+unknown_tag ) {
+ mp_nonlinear_eq(mp, v,mp->cur_exp,false);
+ mp_unstash_cur_exp(mp, mp->cur_exp); goto DONE;
+ } else if ( mp->cur_type==t ) {
+ @<Report redundant or inconsistent equation and |goto done|@>;
+ }
+ break;
+case unknown_types:
+ if ( mp->cur_type==t-unknown_tag ) {
+ mp_nonlinear_eq(mp, mp->cur_exp,lhs,true); goto DONE;
+ } else if ( mp->cur_type==t ) {
+ mp_ring_merge(mp, lhs,mp->cur_exp); goto DONE;
+ } else if ( mp->cur_type==mp_pair_type ) {
+ if ( t==mp_unknown_path ) {
+ mp_pair_to_path(mp); goto RESTART;
+ };
+ }
+ break;
+case mp_transform_type: case mp_color_type:
+case mp_cmykcolor_type: case mp_pair_type:
+ if ( mp->cur_type==t ) {
+ @<Do multiple equations and |goto done|@>;
+ }
+ break;
+case mp_known: case mp_dependent:
+case mp_proto_dependent: case mp_independent:
+ if ( mp->cur_type>=mp_known ) {
+ mp_try_eq(mp, lhs,null); goto DONE;
+ };
+ break;
+case mp_vacuous:
+ break;
+
+@ @<Report redundant or inconsistent equation and |goto done|@>=
+{
+ if ( mp->cur_type<=mp_string_type ) {
+ if ( mp->cur_type==mp_string_type ) {
+ if ( mp_str_vs_str(mp, v,mp->cur_exp)!=0 ) {
+ goto NOT_FOUND;
+ }
+ } else if ( v!=mp->cur_exp ) {
+ goto NOT_FOUND;
+ }
+ @<Exclaim about a redundant equation@>; goto DONE;
+ }
+ print_err("Redundant or inconsistent equation");
+@.Redundant or inconsistent equation@>
+ help2("An equation between already-known quantities can't help.",
+ "But don't worry; continue and I'll just ignore it.");
+ mp_put_get_error(mp); goto DONE;
+NOT_FOUND:
+ print_err("Inconsistent equation");
+@.Inconsistent equation@>
+ help2("The equation I just read contradicts what was said before.",
+ "But don't worry; continue and I'll just ignore it.");
+ mp_put_get_error(mp); goto DONE;
+}
+
+@ @<Do multiple equations and |goto done|@>=
+{
+ p=v+mp->big_node_size[t];
+ q=value(mp->cur_exp)+mp->big_node_size[t];
+ do {
+ p=p-2; q=q-2; mp_try_eq(mp, p,q);
+ } while (p!=v);
+ goto DONE;
+}
+
+@ The first argument to |try_eq| is the location of a value node
+in a capsule that will soon be recycled. The second argument is
+either a location within a pair or transform node pointed to by
+|cur_exp|, or it is |null| (which means that |cur_exp| itself
+serves as the second argument). The idea is to leave |cur_exp| unchanged,
+but to equate the two operands.
+
+@<Declarations@>=
+static void mp_try_eq (MP mp,pointer l, pointer r) ;
+
+@
+@c void mp_try_eq (MP mp,pointer l, pointer r) {
+ pointer p; /* dependency list for right operand minus left operand */
+ int t; /* the type of list |p| */
+ pointer q; /* the constant term of |p| is here */
+ pointer pp; /* dependency list for right operand */
+ int tt; /* the type of list |pp| */
+ boolean copied; /* have we copied a list that ought to be recycled? */
+ @<Remove the left operand from its container, negate it, and
+ put it into dependency list~|p| with constant term~|q|@>;
+ @<Add the right operand to list |p|@>;
+ if ( mp_info(p)==null ) {
+ @<Deal with redundant or inconsistent equation@>;
+ } else {
+ mp_linear_eq(mp, p,t);
+ if ( r==null ) if ( mp->cur_type!=mp_known ) {
+ if ( mp_type(mp->cur_exp)==mp_known ) {
+ pp=mp->cur_exp; mp->cur_exp=value(mp->cur_exp); mp->cur_type=mp_known;
+ mp_free_node(mp, pp,value_node_size);
+ }
+ }
+ }
+}
+
+@ @<Remove the left operand from its container, negate it, and...@>=
+t=mp_type(l);
+if ( t==mp_known ) {
+ t=mp_dependent; p=mp_const_dependency(mp, -value(l)); q=p;
+} else if ( t==mp_independent ) {
+ t=mp_dependent; p=mp_single_dependency(mp, l); negate(value(p));
+ q=mp->dep_final;
+} else {
+ p=dep_list(l); q=p;
+ while (1) {
+ negate(value(q));
+ if ( mp_info(q)==null ) break;
+ q=mp_link(q);
+ }
+ mp_link(prev_dep(l))=mp_link(q); prev_dep(mp_link(q))=prev_dep(l);
+ mp_type(l)=mp_known;
+}
+
+@ @<Deal with redundant or inconsistent equation@>=
+{
+ if ( abs(value(p))>64 ) { /* off by .001 or more */
+ print_err("Inconsistent equation");
+@.Inconsistent equation@>
+ mp_print(mp, " (off by "); mp_print_scaled(mp, value(p));
+ mp_print_char(mp, xord(')'));
+ help2("The equation I just read contradicts what was said before.",
+ "But don't worry; continue and I'll just ignore it.");
+ mp_put_get_error(mp);
+ } else if ( r==null ) {
+ @<Exclaim about a redundant equation@>;
+ }
+ mp_free_node(mp, p,dep_node_size);
+}
+
+@ @<Add the right operand to list |p|@>=
+if ( r==null ) {
+ if ( mp->cur_type==mp_known ) {
+ value(q)=value(q)+mp->cur_exp; goto DONE1;
+ } else {
+ tt=mp->cur_type;
+ if ( tt==mp_independent ) pp=mp_single_dependency(mp, mp->cur_exp);
+ else pp=dep_list(mp->cur_exp);
+ }
+} else {
+ if ( mp_type(r)==mp_known ) {
+ value(q)=value(q)+value(r); goto DONE1;
+ } else {
+ tt=mp_type(r);
+ if ( tt==mp_independent ) pp=mp_single_dependency(mp, r);
+ else pp=dep_list(r);
+ }
+}
+if ( tt!=mp_independent ) copied=false;
+else { copied=true; tt=mp_dependent; };
+@<Add dependency list |pp| of type |tt| to dependency list~|p| of type~|t|@>;
+if ( copied ) mp_flush_node_list(mp, pp);
+DONE1:
+
+@ @<Add dependency list |pp| of type |tt| to dependency list~|p| of type~|t|@>=
+mp->watch_coefs=false;
+if ( t==tt ) {
+ p=mp_p_plus_q(mp, p,pp,t);
+} else if ( t==mp_proto_dependent ) {
+ p=mp_p_plus_fq(mp, p,unity,pp,mp_proto_dependent,mp_dependent);
+} else {
+ q=p;
+ while ( mp_info(q)!=null ) {
+ value(q)=mp_round_fraction(mp, value(q)); q=mp_link(q);
+ }
+ t=mp_proto_dependent; p=mp_p_plus_q(mp, p,pp,t);
+}
+mp->watch_coefs=true;
+
+@ Our next goal is to process type declarations. For this purpose it's
+convenient to have a procedure that scans a $\langle\,$declared
+variable$\,\rangle$ and returns the corresponding token list. After the
+following procedure has acted, the token after the declared variable
+will have been scanned, so it will appear in |cur_cmd|, |cur_mod|,
+and~|cur_sym|.
+
+@<Declarations@>=
+static pointer mp_scan_declared_variable (MP mp) ;
+
+@ @c
+pointer mp_scan_declared_variable (MP mp) {
+ pointer x; /* hash address of the variable's root */
+ pointer h,t; /* head and tail of the token list to be returned */
+ pointer l; /* hash address of left bracket */
+ mp_get_symbol(mp); x=mp->cur_sym;
+ if ( mp->cur_cmd!=tag_token ) mp_clear_symbol(mp, x,false);
+ h=mp_get_avail(mp); mp_info(h)=x; t=h;
+ while (1) {
+ mp_get_x_next(mp);
+ if ( mp->cur_sym==0 ) break;
+ if ( mp->cur_cmd!=tag_token ) if ( mp->cur_cmd!=internal_quantity) {
+ if ( mp->cur_cmd==left_bracket ) {
+ @<Descend past a collective subscript@>;
+ } else {
+ break;
+ }
+ }
+ mp_link(t)=mp_get_avail(mp); t=mp_link(t); mp_info(t)=mp->cur_sym;
+ }
+ if ( (eq_type(x)%outer_tag)!=tag_token ) mp_clear_symbol(mp, x,false);
+ if ( equiv(x)==null ) mp_new_root(mp, x);
+ return h;
+}
+
+@ If the subscript isn't collective, we don't accept it as part of the
+declared variable.
+
+@<Descend past a collective subscript@>=
+{
+ l=mp->cur_sym; mp_get_x_next(mp);
+ if ( mp->cur_cmd!=right_bracket ) {
+ mp_back_input(mp); mp->cur_sym=l; mp->cur_cmd=left_bracket; break;
+ } else {
+ mp->cur_sym=collective_subscript;
+ }
+}
+
+@ Type declarations are introduced by the following primitive operations.
+
+@<Put each...@>=
+mp_primitive(mp, "numeric",type_name,mp_numeric_type);
+@:numeric_}{\&{numeric} primitive@>
+mp_primitive(mp, "string",type_name,mp_string_type);
+@:string_}{\&{string} primitive@>
+mp_primitive(mp, "boolean",type_name,mp_boolean_type);
+@:boolean_}{\&{boolean} primitive@>
+mp_primitive(mp, "path",type_name,mp_path_type);
+@:path_}{\&{path} primitive@>
+mp_primitive(mp, "pen",type_name,mp_pen_type);
+@:pen_}{\&{pen} primitive@>
+mp_primitive(mp, "picture",type_name,mp_picture_type);
+@:picture_}{\&{picture} primitive@>
+mp_primitive(mp, "transform",type_name,mp_transform_type);
+@:transform_}{\&{transform} primitive@>
+mp_primitive(mp, "color",type_name,mp_color_type);
+@:color_}{\&{color} primitive@>
+mp_primitive(mp, "rgbcolor",type_name,mp_color_type);
+@:color_}{\&{rgbcolor} primitive@>
+mp_primitive(mp, "cmykcolor",type_name,mp_cmykcolor_type);
+@:color_}{\&{cmykcolor} primitive@>
+mp_primitive(mp, "pair",type_name,mp_pair_type);
+@:pair_}{\&{pair} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case type_name: mp_print_type(mp, m); break;
+
+@ Now we are ready to handle type declarations, assuming that a
+|type_name| has just been scanned.
+
+@<Declare action procedures for use by |do_statement|@>=
+static void mp_do_type_declaration (MP mp) ;
+
+@ @c
+void mp_do_type_declaration (MP mp) {
+ quarterword t; /* the type being declared */
+ pointer p; /* token list for a declared variable */
+ pointer q; /* value node for the variable */
+ if ( mp->cur_mod>=mp_transform_type )
+ t=mp->cur_mod;
+ else
+ t=mp->cur_mod+unknown_tag;
+ do {
+ p=mp_scan_declared_variable(mp);
+ mp_flush_variable(mp, equiv(mp_info(p)),mp_link(p),false);
+ q=mp_find_variable(mp, p);
+ if ( q!=null ) {
+ mp_type(q)=t; value(q)=null;
+ } else {
+ print_err("Declared variable conflicts with previous vardef");
+@.Declared variable conflicts...@>
+ help2("You can't use, e.g., `numeric foo[]' after `vardef foo'.",
+ "Proceed, and I'll ignore the illegal redeclaration.");
+ mp_put_get_error(mp);
+ }
+ mp_flush_list(mp, p);
+ if ( mp->cur_cmd<comma ) {
+ @<Flush spurious symbols after the declared variable@>;
+ }
+ } while (! end_of_statement);
+}
+
+@ @<Flush spurious symbols after the declared variable@>=
+{
+ print_err("Illegal suffix of declared variable will be flushed");
+@.Illegal suffix...flushed@>
+ help5("Variables in declarations must consist entirely of",
+ "names and collective subscripts, e.g., `x[]a'.",
+ "Are you trying to use a reserved word in a variable name?",
+ "I'm going to discard the junk I found here,",
+ "up to the next comma or the end of the declaration.");
+ if ( mp->cur_cmd==numeric_token )
+ mp->help_line[2]="Explicit subscripts like `x15a' aren't permitted.";
+ mp_put_get_error(mp); mp->scanner_status=flushing;
+ do {
+ get_t_next;
+ @<Decrease the string reference count...@>;
+ } while (mp->cur_cmd<comma); /* either |end_of_statement| or |cur_cmd=comma| */
+ mp->scanner_status=normal;
+}
+
+@ \MP's |main_control| procedure just calls |do_statement| repeatedly
+until coming to the end of the user's program.
+Each execution of |do_statement| concludes with
+|cur_cmd=semicolon|, |end_group|, or |stop|.
+
+@c
+static void mp_main_control (MP mp) {
+ do {
+ mp_do_statement(mp);
+ if ( mp->cur_cmd==end_group ) {
+ print_err("Extra `endgroup'");
+@.Extra `endgroup'@>
+ help2("I'm not currently working on a `begingroup',",
+ "so I had better not try to end anything.");
+ mp_flush_error(mp, 0);
+ }
+ } while (mp->cur_cmd!=stop);
+}
+int mp_run (MP mp) {
+ if (mp->history < mp_fatal_error_stop ) {
+ xfree(mp->jump_buf);
+ mp->jump_buf = malloc(sizeof(jmp_buf));
+ if (mp->jump_buf == NULL || setjmp(*(mp->jump_buf)) != 0)
+ return mp->history;
+ mp_main_control(mp); /* come to life */
+ mp_final_cleanup(mp); /* prepare for death */
+ mp_close_files_and_terminate(mp);
+ }
+ return mp->history;
+}
+
+@ For |mp_execute|, we need to define a structure to store the
+redirected input and output. This structure holds the five relevant
+streams: the three informational output streams, the PostScript
+generation stream, and the input stream. These streams have many
+things in common, so it makes sense to give them their own structure
+definition.
+
+\item{fptr} is a virtual file pointer
+\item{data} is the data this stream holds
+\item{cur} is a cursor pointing into |data|
+\item{size} is the allocated length of the data stream
+\item{used} is the actual length of the data stream
+
+There are small differences between input and output: |term_in| never
+uses |used|, whereas the other four never use |cur|.
+
+@<Exported types@>=
+typedef struct {
+ void * fptr;
+ char * data;
+ char * cur;
+ size_t size;
+ size_t used;
+} mp_stream;
+
+typedef struct {
+ mp_stream term_out;
+ mp_stream error_out;
+ mp_stream log_out;
+ mp_stream ps_out;
+ mp_stream term_in;
+ struct mp_edge_object *edges;
+} mp_run_data;
+
+@ We need a function to clear an output stream, this is called at the
+beginning of |mp_execute|. We also need one for destroying an output
+stream, this is called just before a stream is (re)opened.
+
+@c
+static void mp_reset_stream(mp_stream *str) {
+ xfree(str->data);
+ str->cur = NULL;
+ str->size = 0;
+ str->used = 0;
+}
+static void mp_free_stream(mp_stream *str) {
+ xfree(str->fptr);
+ mp_reset_stream(str);
+}
+
+@ @<Declarations@>=
+static void mp_reset_stream(mp_stream *str);
+static void mp_free_stream(mp_stream *str);
+
+@ The global instance contains a pointer instead of the actual structure
+even though it is essentially static, because that makes it is easier to move
+the object around.
+
+@<Global ...@>=
+mp_run_data run_data;
+
+@ Another type is needed: the indirection will overload some of the
+file pointer objects in the instance (but not all). For clarity, an
+indirect object is used that wraps a |FILE *|.
+
+@<Types ... @>=
+typedef struct File {
+ FILE *f;
+} File;
+
+@ Here are all of the functions that need to be overloaded for |mp_execute|.
+
+@<Declarations@>=
+static void *mplib_open_file(MP mp, const char *fname, const char *fmode, int ftype);
+static int mplib_get_char(void *f, mp_run_data * mplib_data);
+static void mplib_unget_char(void *f, mp_run_data * mplib_data, int c);
+static char *mplib_read_ascii_file(MP mp, void *ff, size_t * size);
+static void mplib_write_ascii_file(MP mp, void *ff, const char *s);
+static void mplib_read_binary_file(MP mp, void *ff, void **data, size_t * size);
+static void mplib_write_binary_file(MP mp, void *ff, void *s, size_t size);
+static void mplib_close_file(MP mp, void *ff);
+static int mplib_eof_file(MP mp, void *ff);
+static void mplib_flush_file(MP mp, void *ff);
+static void mplib_shipout_backend(MP mp, int h);
+
+@ The |xmalloc(1,1)| calls make sure the stored indirection values are unique.
+
+@d reset_stream(a) do {
+ mp_reset_stream(&(a));
+ if (!ff->f) {
+ ff->f = xmalloc(1,1);
+ (a).fptr = ff->f;
+ } } while (0)
+
+@c
+
+static void *mplib_open_file(MP mp, const char *fname, const char *fmode, int ftype)
+{
+ File *ff = xmalloc(1, sizeof(File));
+ mp_run_data *run = mp_rundata(mp);
+ ff->f = NULL;
+ if (ftype == mp_filetype_terminal) {
+ if (fmode[0] == 'r') {
+ if (!ff->f) {
+ ff->f = xmalloc(1,1);
+ run->term_in.fptr = ff->f;
+ }
+ } else {
+ reset_stream(run->term_out);
+ }
+ } else if (ftype == mp_filetype_error) {
+ reset_stream(run->error_out);
+ } else if (ftype == mp_filetype_log) {
+ reset_stream(run->log_out);
+ } else if (ftype == mp_filetype_postscript) {
+ mp_free_stream(&(run->ps_out));
+ ff->f = xmalloc(1,1);
+ run->ps_out.fptr = ff->f;
+ } else {
+ char realmode[3];
+ char *f = (mp->find_file)(mp, fname, fmode, ftype);
+ if (f == NULL)
+ return NULL;
+ realmode[0] = *fmode;
+ realmode[1] = 'b';
+ realmode[2] = 0;
+ ff->f = fopen(f, realmode);
+ free(f);
+ if ((fmode[0] == 'r') && (ff->f == NULL)) {
+ free(ff);
+ return NULL;
+ }
+ }
+ return ff;
+}
+
+static int mplib_get_char(void *f, mp_run_data * run)
+{
+ int c;
+ if (f == run->term_in.fptr && run->term_in.data != NULL) {
+ if (run->term_in.size == 0) {
+ if (run->term_in.cur != NULL) {
+ run->term_in.cur = NULL;
+ } else {
+ xfree(run->term_in.data);
+ }
+ c = EOF;
+ } else {
+ run->term_in.size--;
+ c = *(run->term_in.cur)++;
+ }
+ } else {
+ c = fgetc(f);
+ }
+ return c;
+}
+
+static void mplib_unget_char(void *f, mp_run_data * run, int c)
+{
+ if (f == run->term_in.fptr && run->term_in.cur != NULL) {
+ run->term_in.size++;
+ run->term_in.cur--;
+ } else {
+ ungetc(c, f);
+ }
+}
+
+
+static char *mplib_read_ascii_file(MP mp, void *ff, size_t * size)
+{
+ char *s = NULL;
+ if (ff != NULL) {
+ int c;
+ size_t len = 0, lim = 128;
+ mp_run_data *run = mp_rundata(mp);
+ FILE *f = ((File *) ff)->f;
+ if (f == NULL)
+ return NULL;
+ *size = 0;
+ c = mplib_get_char(f, run);
+ if (c == EOF)
+ return NULL;
+ s = malloc(lim);
+ if (s == NULL)
+ return NULL;
+ while (c != EOF && c != '\n' && c != '\r') {
+ if (len == lim) {
+ s = xrealloc(s, (lim + (lim >> 2)),1);
+ if (s == NULL)
+ return NULL;
+ lim += (lim >> 2);
+ }
+ s[len++] = c;
+ c = mplib_get_char(f, run);
+ }
+ if (c == '\r') {
+ c = mplib_get_char(f, run);
+ if (c != EOF && c != '\n')
+ mplib_unget_char(f, run, c);
+ }
+ s[len] = 0;
+ *size = len;
+ }
+ return s;
+}
+
+static void mp_append_string (MP mp, mp_stream *a,const char *b) {
+ size_t l = strlen(b);
+ if ((a->used+l)>=a->size) {
+ a->size += 256+(a->size)/5+l;
+ a->data = xrealloc(a->data,a->size,1);
+ }
+ (void)strcpy(a->data+a->used,b);
+ a->used += l;
+}
+
+
+static void mplib_write_ascii_file(MP mp, void *ff, const char *s)
+{
+ if (ff != NULL) {
+ void *f = ((File *) ff)->f;
+ mp_run_data *run = mp_rundata(mp);
+ if (f != NULL) {
+ if (f == run->term_out.fptr) {
+ mp_append_string(mp,&(run->term_out), s);
+ } else if (f == run->error_out.fptr) {
+ mp_append_string(mp,&(run->error_out), s);
+ } else if (f == run->log_out.fptr) {
+ mp_append_string(mp,&(run->log_out), s);
+ } else if (f == run->ps_out.fptr) {
+ mp_append_string(mp,&(run->ps_out), s);
+ } else {
+ fprintf((FILE *) f, "%s", s);
+ }
+ }
+ }
+}
+
+static void mplib_read_binary_file(MP mp, void *ff, void **data, size_t * size)
+{
+ (void) mp;
+ if (ff != NULL) {
+ size_t len = 0;
+ FILE *f = ((File *) ff)->f;
+ if (f != NULL)
+ len = fread(*data, 1, *size, f);
+ *size = len;
+ }
+}
+
+static void mplib_write_binary_file(MP mp, void *ff, void *s, size_t size)
+{
+ (void) mp;
+ if (ff != NULL) {
+ FILE *f = ((File *) ff)->f;
+ if (f != NULL)
+ (void)fwrite(s, size, 1, f);
+ }
+}
+
+static void mplib_close_file(MP mp, void *ff)
+{
+ if (ff != NULL) {
+ mp_run_data *run = mp_rundata(mp);
+ void *f = ((File *) ff)->f;
+ if (f != NULL) {
+ if (f != run->term_out.fptr
+ && f != run->error_out.fptr
+ && f != run->log_out.fptr
+ && f != run->ps_out.fptr
+ && f != run->term_in.fptr) {
+ fclose(f);
+ }
+ }
+ free(ff);
+ }
+}
+
+static int mplib_eof_file(MP mp, void *ff)
+{
+ if (ff != NULL) {
+ mp_run_data *run = mp_rundata(mp);
+ FILE *f = ((File *) ff)->f;
+ if (f == NULL)
+ return 1;
+ if (f == run->term_in.fptr && run->term_in.data != NULL) {
+ return (run->term_in.size == 0);
+ }
+ return feof(f);
+ }
+ return 1;
+}
+
+static void mplib_flush_file(MP mp, void *ff)
+{
+ (void) mp;
+ (void) ff;
+ return;
+}
+
+static void mplib_shipout_backend(MP mp, int h)
+{
+ mp_edge_object *hh = mp_gr_export(mp, h);
+ if (hh) {
+ mp_run_data *run = mp_rundata(mp);
+ if (run->edges==NULL) {
+ run->edges = hh;
+ } else {
+ mp_edge_object *p = run->edges;
+ while (p->next!=NULL) { p = p->next; }
+ p->next = hh;
+ }
+ }
+}
+
+
+@ This is where we fill them all in.
+@<Prepare function pointers for non-interactive use@>=
+{
+ mp->open_file = mplib_open_file;
+ mp->close_file = mplib_close_file;
+ mp->eof_file = mplib_eof_file;
+ mp->flush_file = mplib_flush_file;
+ mp->write_ascii_file = mplib_write_ascii_file;
+ mp->read_ascii_file = mplib_read_ascii_file;
+ mp->write_binary_file = mplib_write_binary_file;
+ mp->read_binary_file = mplib_read_binary_file;
+ mp->shipout_backend = mplib_shipout_backend;
+}
+
+@ Perhaps this is the most important API function in the library.
+
+@<Exported function ...@>=
+extern mp_run_data *mp_rundata (MP mp) ;
+
+@ @c
+mp_run_data *mp_rundata (MP mp) {
+ return &(mp->run_data);
+}
+
+@ @<Dealloc ...@>=
+mp_free_stream(&(mp->run_data.term_in));
+mp_free_stream(&(mp->run_data.term_out));
+mp_free_stream(&(mp->run_data.log_out));
+mp_free_stream(&(mp->run_data.error_out));
+mp_free_stream(&(mp->run_data.ps_out));
+
+@ @<Finish non-interactive use@>=
+xfree(mp->term_out);
+xfree(mp->term_in);
+xfree(mp->err_out);
+
+@ @<Start non-interactive work@>=
+@<Initialize the output routines@>;
+mp->input_ptr=0; mp->max_in_stack=0;
+mp->in_open=0; mp->open_parens=0; mp->max_buf_stack=0;
+mp->param_ptr=0; mp->max_param_stack=0;
+start = loc = iindex = 0; mp->first = 0;
+line=0; name=is_term;
+mp->mpx_name[0]=absent;
+mp->force_eof=false;
+t_open_in;
+mp->scanner_status=normal;
+if (mp->mem_ident==NULL) {
+ if ( ! mp_load_mem_file(mp) ) {
+ (mp->close_file)(mp, mp->mem_file);
+ mp->history = mp_fatal_error_stop;
+ return mp->history;
+ }
+ (mp->close_file)(mp, mp->mem_file);
+}
+mp_fix_date_and_time(mp);
+if (mp->random_seed==0)
+ mp->random_seed = (mp->internal[mp_time] / unity)+mp->internal[mp_day];
+mp_init_randoms(mp, mp->random_seed);
+@<Initialize the print |selector|...@>;
+mp_open_log_file(mp);
+mp_set_job_id(mp);
+mp_init_map_file(mp, mp->troff_mode);
+mp->history=mp_spotless; /* ready to go! */
+if (mp->troff_mode) {
+ mp->internal[mp_gtroffmode]=unity;
+ mp->internal[mp_prologues]=unity;
+}
+if ( mp->start_sym>0 ) { /* insert the `\&{everyjob}' symbol */
+ mp->cur_sym=mp->start_sym; mp_back_input(mp);
+}
+
+@ @c
+int mp_execute (MP mp, char *s, size_t l) {
+ mp_reset_stream(&(mp->run_data.term_out));
+ mp_reset_stream(&(mp->run_data.log_out));
+ mp_reset_stream(&(mp->run_data.error_out));
+ mp_reset_stream(&(mp->run_data.ps_out));
+ if (mp->finished) {
+ return mp->history;
+ } else if (!mp->noninteractive) {
+ mp->history = mp_fatal_error_stop ;
+ return mp->history;
+ }
+ if (mp->history < mp_fatal_error_stop ) {
+ xfree(mp->jump_buf);
+ mp->jump_buf = malloc(sizeof(jmp_buf));
+ if (mp->jump_buf == NULL || setjmp(*(mp->jump_buf)) != 0) {
+ return mp->history;
+ }
+ if (s==NULL) { /* this signals EOF */
+ mp_final_cleanup(mp); /* prepare for death */
+ mp_close_files_and_terminate(mp);
+ return mp->history;
+ }
+ mp->tally=0;
+ mp->term_offset=0; mp->file_offset=0;
+ /* Perhaps some sort of warning here when |data| is not
+ * yet exhausted would be nice ... this happens after errors
+ */
+ if (mp->run_data.term_in.data)
+ xfree(mp->run_data.term_in.data);
+ mp->run_data.term_in.data = xstrdup(s);
+ mp->run_data.term_in.cur = mp->run_data.term_in.data;
+ mp->run_data.term_in.size = l;
+ if (mp->run_state == 0) {
+ mp->selector=term_only;
+ @<Start non-interactive work@>;
+ }
+ mp->run_state =1;
+ (void)mp_input_ln(mp,mp->term_in);
+ mp_firm_up_the_line(mp);
+ mp->buffer[limit]=xord('%');
+ mp->first=(size_t)(limit+1);
+ loc=start;
+ do {
+ mp_do_statement(mp);
+ } while (mp->cur_cmd!=stop);
+ mp_final_cleanup(mp);
+ mp_close_files_and_terminate(mp);
+ }
+ return mp->history;
+}
+
+@ This function cleans up
+@c
+int mp_finish (MP mp) {
+ int history = 0;
+ if (mp->finished || mp->history >= mp_fatal_error_stop) {
+ history = mp->history;
+ mp_free(mp);
+ return history;
+ }
+ xfree(mp->jump_buf);
+ mp->jump_buf = malloc(sizeof(jmp_buf));
+ if (mp->jump_buf == NULL || setjmp(*(mp->jump_buf)) != 0) {
+ history = mp->history;
+ } else {
+ history = mp->history;
+ mp_final_cleanup(mp); /* prepare for death */
+ }
+ mp_close_files_and_terminate(mp);
+ mp_free(mp);
+ return history;
+}
+
+@ People may want to know the library version
+@c
+char * mp_metapost_version (void) {
+ return mp_strdup(metapost_version);
+}
+
+@ @<Exported function headers@>=
+int mp_run (MP mp);
+int mp_execute (MP mp, char *s, size_t l);
+int mp_finish (MP mp);
+char * mp_metapost_version (void);
+
+@ @<Put each...@>=
+mp_primitive(mp, "end",stop,0);
+@:end_}{\&{end} primitive@>
+mp_primitive(mp, "dump",stop,1);
+@:dump_}{\&{dump} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case stop:
+ if ( m==0 ) mp_print(mp, "end");
+ else mp_print(mp, "dump");
+ break;
+
+@* \[41] Commands.
+Let's turn now to statements that are classified as ``commands'' because
+of their imperative nature. We'll begin with simple ones, so that it
+will be clear how to hook command processing into the |do_statement| routine;
+then we'll tackle the tougher commands.
+
+Here's one of the simplest:
+
+@<Cases of |do_statement|...@>=
+case mp_random_seed: mp_do_random_seed(mp); break;
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_do_random_seed (MP mp) ;
+
+@ @c void mp_do_random_seed (MP mp) {
+ mp_get_x_next(mp);
+ if ( mp->cur_cmd!=assignment ) {
+ mp_missing_err(mp, ":=");
+@.Missing `:='@>
+ help1("Always say `randomseed:=<numeric expression>'.");
+ mp_back_error(mp);
+ };
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_known ) {
+ exp_err("Unknown value will be ignored");
+@.Unknown value...ignored@>
+ help2("Your expression was too random for me to handle,",
+ "so I won't change the random seed just now.");
+ mp_put_get_flush_error(mp, 0);
+ } else {
+ @<Initialize the random seed to |cur_exp|@>;
+ }
+}
+
+@ @<Initialize the random seed to |cur_exp|@>=
+{
+ mp_init_randoms(mp, mp->cur_exp);
+ if ( mp->selector>=log_only && mp->selector<write_file) {
+ mp->old_setting=mp->selector; mp->selector=log_only;
+ mp_print_nl(mp, "{randomseed:=");
+ mp_print_scaled(mp, mp->cur_exp);
+ mp_print_char(mp, xord('}'));
+ mp_print_nl(mp, ""); mp->selector=mp->old_setting;
+ }
+}
+
+@ And here's another simple one (somewhat different in flavor):
+
+@<Cases of |do_statement|...@>=
+case mode_command:
+ mp_print_ln(mp); mp->interaction=mp->cur_mod;
+ @<Initialize the print |selector| based on |interaction|@>;
+ if ( mp->log_opened ) mp->selector=mp->selector+2;
+ mp_get_x_next(mp);
+ break;
+
+@ @<Put each...@>=
+mp_primitive(mp, "batchmode",mode_command,mp_batch_mode);
+@:mp_batch_mode_}{\&{batchmode} primitive@>
+mp_primitive(mp, "nonstopmode",mode_command,mp_nonstop_mode);
+@:mp_nonstop_mode_}{\&{nonstopmode} primitive@>
+mp_primitive(mp, "scrollmode",mode_command,mp_scroll_mode);
+@:mp_scroll_mode_}{\&{scrollmode} primitive@>
+mp_primitive(mp, "errorstopmode",mode_command,mp_error_stop_mode);
+@:mp_error_stop_mode_}{\&{errorstopmode} primitive@>
+
+@ @<Cases of |print_cmd_mod|...@>=
+case mode_command:
+ switch (m) {
+ case mp_batch_mode: mp_print(mp, "batchmode"); break;
+ case mp_nonstop_mode: mp_print(mp, "nonstopmode"); break;
+ case mp_scroll_mode: mp_print(mp, "scrollmode"); break;
+ default: mp_print(mp, "errorstopmode"); break;
+ }
+ break;
+
+@ The `\&{inner}' and `\&{outer}' commands are only slightly harder.
+
+@<Cases of |do_statement|...@>=
+case protection_command: mp_do_protection(mp); break;
+
+@ @<Put each...@>=
+mp_primitive(mp, "inner",protection_command,0);
+@:inner_}{\&{inner} primitive@>
+mp_primitive(mp, "outer",protection_command,1);
+@:outer_}{\&{outer} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case protection_command:
+ if ( m==0 ) mp_print(mp, "inner");
+ else mp_print(mp, "outer");
+ break;
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_do_protection (MP mp) ;
+
+@ @c void mp_do_protection (MP mp) {
+ int m; /* 0 to unprotect, 1 to protect */
+ halfword t; /* the |eq_type| before we change it */
+ m=mp->cur_mod;
+ do {
+ mp_get_symbol(mp); t=eq_type(mp->cur_sym);
+ if ( m==0 ) {
+ if ( t>=outer_tag )
+ eq_type(mp->cur_sym)=t-outer_tag;
+ } else if ( t<outer_tag ) {
+ eq_type(mp->cur_sym)=t+outer_tag;
+ }
+ mp_get_x_next(mp);
+ } while (mp->cur_cmd==comma);
+}
+
+@ \MP\ never defines the tokens `\.(' and `\.)' to be primitives, but
+plain \MP\ begins with the declaration `\&{delimiters} \.{()}'. Such a
+declaration assigns the command code |left_delimiter| to `\.{(}' and
+|right_delimiter| to `\.{)}'; the |equiv| of each delimiter is the
+hash address of its mate.
+
+@<Cases of |do_statement|...@>=
+case delimiters: mp_def_delims(mp); break;
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_def_delims (MP mp) ;
+
+@ @c void mp_def_delims (MP mp) {
+ pointer l_delim,r_delim; /* the new delimiter pair */
+ mp_get_clear_symbol(mp); l_delim=mp->cur_sym;
+ mp_get_clear_symbol(mp); r_delim=mp->cur_sym;
+ eq_type(l_delim)=left_delimiter; equiv(l_delim)=r_delim;
+ eq_type(r_delim)=right_delimiter; equiv(r_delim)=l_delim;
+ mp_get_x_next(mp);
+}
+
+@ Here is a procedure that is called when \MP\ has reached a point
+where some right delimiter is mandatory.
+
+@<Declarations@>=
+static void mp_check_delimiter (MP mp,pointer l_delim, pointer r_delim);
+
+@ @c
+void mp_check_delimiter (MP mp,pointer l_delim, pointer r_delim) {
+ if ( mp->cur_cmd==right_delimiter )
+ if ( mp->cur_mod==l_delim )
+ return;
+ if ( mp->cur_sym!=r_delim ) {
+ mp_missing_err(mp, str(text(r_delim)));
+@.Missing `)'@>
+ help2("I found no right delimiter to match a left one. So I've",
+ "put one in, behind the scenes; this may fix the problem.");
+ mp_back_error(mp);
+ } else {
+ print_err("The token `"); mp_print_text(r_delim);
+@.The token...delimiter@>
+ mp_print(mp, "' is no longer a right delimiter");
+ help3("Strange: This token has lost its former meaning!",
+ "I'll read it as a right delimiter this time;",
+ "but watch out, I'll probably miss it later.");
+ mp_error(mp);
+ }
+}
+
+@ The next four commands save or change the values associated with tokens.
+
+@<Cases of |do_statement|...@>=
+case save_command:
+ do {
+ mp_get_symbol(mp); mp_save_variable(mp, mp->cur_sym); mp_get_x_next(mp);
+ } while (mp->cur_cmd==comma);
+ break;
+case interim_command: mp_do_interim(mp); break;
+case let_command: mp_do_let(mp); break;
+case new_internal: mp_do_new_internal(mp); break;
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_do_statement (MP mp);
+static void mp_do_interim (MP mp);
+
+@ @c void mp_do_interim (MP mp) {
+ mp_get_x_next(mp);
+ if ( mp->cur_cmd!=internal_quantity ) {
+ print_err("The token `");
+@.The token...quantity@>
+ if ( mp->cur_sym==0 ) mp_print(mp, "(%CAPSULE)");
+ else mp_print_text(mp->cur_sym);
+ mp_print(mp, "' isn't an internal quantity");
+ help1("Something like `tracingonline' should follow `interim'.");
+ mp_back_error(mp);
+ } else {
+ mp_save_internal(mp, mp->cur_mod); mp_back_input(mp);
+ }
+ mp_do_statement(mp);
+}
+
+@ The following procedure is careful not to undefine the left-hand symbol
+too soon, lest commands like `{\tt let x=x}' have a surprising effect.
+
+@<Declare action procedures for use by |do_statement|@>=
+static void mp_do_let (MP mp) ;
+
+@ @c void mp_do_let (MP mp) {
+ pointer l; /* hash location of the left-hand symbol */
+ mp_get_symbol(mp); l=mp->cur_sym; mp_get_x_next(mp);
+ if ( mp->cur_cmd!=equals ) if ( mp->cur_cmd!=assignment ) {
+ mp_missing_err(mp, "=");
+@.Missing `='@>
+ help3("You should have said `let symbol = something'.",
+ "But don't worry; I'll pretend that an equals sign",
+ "was present. The next token I read will be `something'.");
+ mp_back_error(mp);
+ }
+ mp_get_symbol(mp);
+ switch (mp->cur_cmd) {
+ case defined_macro: case secondary_primary_macro:
+ case tertiary_secondary_macro: case expression_tertiary_macro:
+ add_mac_ref(mp->cur_mod);
+ break;
+ default:
+ break;
+ }
+ mp_clear_symbol(mp, l,false); eq_type(l)=mp->cur_cmd;
+ if ( mp->cur_cmd==tag_token ) equiv(l)=null;
+ else equiv(l)=mp->cur_mod;
+ mp_get_x_next(mp);
+}
+
+@ @<Declarations@>=
+static void mp_do_new_internal (MP mp) ;
+
+@ @<Internal library ...@>=
+void mp_grow_internals (MP mp, int l);
+
+@ @c
+void mp_grow_internals (MP mp, int l) {
+ scaled *internal;
+ char * *int_name;
+ int k;
+ if ( hash_end+l>max_halfword ) {
+ mp_confusion(mp, "out of memory space"); /* can't be reached */
+ }
+ int_name = xmalloc ((l+1),sizeof(char *));
+ internal = xmalloc ((l+1),sizeof(scaled));
+ for (k=0;k<=l; k++ ) {
+ if (k<=mp->max_internal) {
+ internal[k]=mp->internal[k];
+ int_name[k]=mp->int_name[k];
+ } else {
+ internal[k]=0;
+ int_name[k]=NULL;
+ }
+ }
+ xfree(mp->internal); xfree(mp->int_name);
+ mp->int_name = int_name;
+ mp->internal = internal;
+ mp->max_internal = l;
+}
+
+void mp_do_new_internal (MP mp) {
+ do {
+ if ( mp->int_ptr==mp->max_internal ) {
+ mp_grow_internals(mp, (mp->max_internal + (mp->max_internal/4)));
+ }
+ mp_get_clear_symbol(mp); incr(mp->int_ptr);
+ eq_type(mp->cur_sym)=internal_quantity;
+ equiv(mp->cur_sym)=mp->int_ptr;
+ if(mp->int_name[mp->int_ptr]!=NULL)
+ xfree(mp->int_name[mp->int_ptr]);
+ mp->int_name[mp->int_ptr]=str(text(mp->cur_sym));
+ mp->internal[mp->int_ptr]=0;
+ mp_get_x_next(mp);
+ } while (mp->cur_cmd==comma);
+}
+
+@ @<Dealloc variables@>=
+for (k=0;k<=mp->max_internal;k++) {
+ xfree(mp->int_name[k]);
+}
+xfree(mp->internal);
+xfree(mp->int_name);
+
+
+@ The various `\&{show}' commands are distinguished by modifier fields
+in the usual way.
+
+@d show_token_code 0 /* show the meaning of a single token */
+@d show_stats_code 1 /* show current memory and string usage */
+@d show_code 2 /* show a list of expressions */
+@d show_var_code 3 /* show a variable and its descendents */
+@d show_dependencies_code 4 /* show dependent variables in terms of independents */
+
+@<Put each...@>=
+mp_primitive(mp, "showtoken",show_command,show_token_code);
+@:show_token_}{\&{showtoken} primitive@>
+mp_primitive(mp, "showstats",show_command,show_stats_code);
+@:show_stats_}{\&{showstats} primitive@>
+mp_primitive(mp, "show",show_command,show_code);
+@:show_}{\&{show} primitive@>
+mp_primitive(mp, "showvariable",show_command,show_var_code);
+@:show_var_}{\&{showvariable} primitive@>
+mp_primitive(mp, "showdependencies",show_command,show_dependencies_code);
+@:show_dependencies_}{\&{showdependencies} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case show_command:
+ switch (m) {
+ case show_token_code:mp_print(mp, "showtoken"); break;
+ case show_stats_code:mp_print(mp, "showstats"); break;
+ case show_code:mp_print(mp, "show"); break;
+ case show_var_code:mp_print(mp, "showvariable"); break;
+ default: mp_print(mp, "showdependencies"); break;
+ }
+ break;
+
+@ @<Cases of |do_statement|...@>=
+case show_command:mp_do_show_whatever(mp); break;
+
+@ The value of |cur_mod| controls the |verbosity| in the |print_exp| routine:
+if it's |show_code|, complicated structures are abbreviated, otherwise
+they aren't.
+
+@<Declare action procedures for use by |do_statement|@>=
+static void mp_do_show (MP mp) ;
+
+@ @c void mp_do_show (MP mp) {
+ do {
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ mp_print_nl(mp, ">> ");
+@.>>@>
+ mp_print_exp(mp, null,2); mp_flush_cur_exp(mp, 0);
+ } while (mp->cur_cmd==comma);
+}
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_disp_token (MP mp) ;
+
+@ @c void mp_disp_token (MP mp) {
+ mp_print_nl(mp, "> ");
+@.>\relax@>
+ if ( mp->cur_sym==0 ) {
+ @<Show a numeric or string or capsule token@>;
+ } else {
+ mp_print_text(mp->cur_sym); mp_print_char(mp, xord('='));
+ if ( eq_type(mp->cur_sym)>=outer_tag ) mp_print(mp, "(outer) ");
+ mp_print_cmd_mod(mp, mp->cur_cmd,mp->cur_mod);
+ if ( mp->cur_cmd==defined_macro ) {
+ mp_print_ln(mp); mp_show_macro(mp, mp->cur_mod,null,100000);
+ } /* this avoids recursion between |show_macro| and |print_cmd_mod| */
+@^recursion@>
+ }
+}
+
+@ @<Show a numeric or string or capsule token@>=
+{
+ if ( mp->cur_cmd==numeric_token ) {
+ mp_print_scaled(mp, mp->cur_mod);
+ } else if ( mp->cur_cmd==capsule_token ) {
+ mp_print_capsule(mp,mp->cur_mod);
+ } else {
+ mp_print_char(mp, xord('"'));
+ mp_print_str(mp, mp->cur_mod); mp_print_char(mp, xord('"'));
+ delete_str_ref(mp->cur_mod);
+ }
+}
+
+@ The following cases of |print_cmd_mod| might arise in connection
+with |disp_token|, although they don't necessarily correspond to
+primitive tokens.
+
+@<Cases of |print_cmd_...@>=
+case left_delimiter:
+case right_delimiter:
+ if ( c==left_delimiter ) mp_print(mp, "left");
+ else mp_print(mp, "right");
+ mp_print(mp, " delimiter that matches ");
+ mp_print_text(m);
+ break;
+case tag_token:
+ if ( m==null ) mp_print(mp, "tag");
+ else mp_print(mp, "variable");
+ break;
+case defined_macro:
+ mp_print(mp, "macro:");
+ break;
+case secondary_primary_macro:
+case tertiary_secondary_macro:
+case expression_tertiary_macro:
+ mp_print_cmd_mod(mp, macro_def,c);
+ mp_print(mp, "'d macro:");
+ mp_print_ln(mp); mp_show_token_list(mp, mp_link(mp_link(m)),null,1000,0);
+ break;
+case repeat_loop:
+ mp_print(mp, "[repeat the loop]");
+ break;
+case internal_quantity:
+ mp_print(mp, mp->int_name[m]);
+ break;
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_do_show_token (MP mp) ;
+
+@ @c void mp_do_show_token (MP mp) {
+ do {
+ get_t_next; mp_disp_token(mp);
+ mp_get_x_next(mp);
+ } while (mp->cur_cmd==comma);
+}
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_do_show_stats (MP mp) ;
+
+@ @c void mp_do_show_stats (MP mp) {
+ mp_print_nl(mp, "Memory usage ");
+@.Memory usage...@>
+ mp_print_int(mp, mp->var_used); mp_print_char(mp, xord('&')); mp_print_int(mp, mp->dyn_used);
+ mp_print(mp, " ("); mp_print_int(mp, mp->hi_mem_min-mp->lo_mem_max-1);
+ mp_print(mp, " still untouched)"); mp_print_ln(mp);
+ mp_print_nl(mp, "String usage ");
+ mp_print_int(mp, mp->strs_in_use-mp->init_str_use);
+ mp_print_char(mp, xord('&')); mp_print_int(mp, mp->pool_in_use-mp->init_pool_ptr);
+ mp_print(mp, " (");
+ mp_print_int(mp, mp->max_strings-1-mp->strs_used_up); mp_print_char(mp, xord('&'));
+ mp_print_int(mp, mp->pool_size-mp->pool_ptr);
+ mp_print(mp, " now untouched)"); mp_print_ln(mp);
+ mp_get_x_next(mp);
+}
+
+@ Here's a recursive procedure that gives an abbreviated account
+of a variable, for use by |do_show_var|.
+
+@<Declare action procedures for use by |do_statement|@>=
+static void mp_disp_var (MP mp,pointer p) ;
+
+@ @c void mp_disp_var (MP mp,pointer p) {
+ pointer q; /* traverses attributes and subscripts */
+ int n; /* amount of macro text to show */
+ if ( mp_type(p)==mp_structured ) {
+ @<Descend the structure@>;
+ } else if ( mp_type(p)>=mp_unsuffixed_macro ) {
+ @<Display a variable macro@>;
+ } else if ( mp_type(p)!=undefined ){
+ mp_print_nl(mp, ""); mp_print_variable_name(mp, p);
+ mp_print_char(mp, xord('='));
+ mp_print_exp(mp, p,0);
+ }
+}
+
+@ @<Descend the structure@>=
+{
+ q=attr_head(p);
+ do { mp_disp_var(mp, q); q=mp_link(q); } while (q!=end_attr);
+ q=subscr_head(p);
+ while ( mp_name_type(q)==mp_subscr ) {
+ mp_disp_var(mp, q); q=mp_link(q);
+ }
+}
+
+@ @<Display a variable macro@>=
+{
+ mp_print_nl(mp, ""); mp_print_variable_name(mp, p);
+ if ( mp_type(p)>mp_unsuffixed_macro )
+ mp_print(mp, "@@#"); /* |suffixed_macro| */
+ mp_print(mp, "=macro:");
+ if ( (int)mp->file_offset>=mp->max_print_line-20 ) n=5;
+ else n=mp->max_print_line-mp->file_offset-15;
+ mp_show_macro(mp, value(p),null,n);
+}
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_do_show_var (MP mp) ;
+
+@ @c void mp_do_show_var (MP mp) {
+ do {
+ get_t_next;
+ if ( mp->cur_sym>0 ) if ( mp->cur_sym<=hash_end )
+ if ( mp->cur_cmd==tag_token ) if ( mp->cur_mod!=null ) {
+ mp_disp_var(mp, mp->cur_mod); goto DONE;
+ }
+ mp_disp_token(mp);
+ DONE:
+ mp_get_x_next(mp);
+ } while (mp->cur_cmd==comma);
+}
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_do_show_dependencies (MP mp) ;
+
+@ @c void mp_do_show_dependencies (MP mp) {
+ pointer p; /* link that runs through all dependencies */
+ p=mp_link(dep_head);
+ while ( p!=dep_head ) {
+ if ( mp_interesting(mp, p) ) {
+ mp_print_nl(mp, ""); mp_print_variable_name(mp, p);
+ if ( mp_type(p)==mp_dependent ) mp_print_char(mp, xord('='));
+ else mp_print(mp, " = "); /* extra spaces imply proto-dependency */
+ mp_print_dependency(mp, dep_list(p),mp_type(p));
+ }
+ p=dep_list(p);
+ while ( mp_info(p)!=null ) p=mp_link(p);
+ p=mp_link(p);
+ }
+ mp_get_x_next(mp);
+}
+
+@ Finally we are ready for the procedure that governs all of the
+show commands.
+
+@<Declare action procedures for use by |do_statement|@>=
+static void mp_do_show_whatever (MP mp) ;
+
+@ @c void mp_do_show_whatever (MP mp) {
+ if ( mp->interaction==mp_error_stop_mode ) wake_up_terminal;
+ switch (mp->cur_mod) {
+ case show_token_code:mp_do_show_token(mp); break;
+ case show_stats_code:mp_do_show_stats(mp); break;
+ case show_code:mp_do_show(mp); break;
+ case show_var_code:mp_do_show_var(mp); break;
+ case show_dependencies_code:mp_do_show_dependencies(mp); break;
+ } /* there are no other cases */
+ if ( mp->internal[mp_showstopping]>0 ){
+ print_err("OK");
+@.OK@>
+ if ( mp->interaction<mp_error_stop_mode ) {
+ help0; decr(mp->error_count);
+ } else {
+ help1("This isn't an error message; I'm just showing something.");
+ }
+ if ( mp->cur_cmd==semicolon ) mp_error(mp);
+ else mp_put_get_error(mp);
+ }
+}
+
+@ The `\&{addto}' command needs the following additional primitives:
+
+@d double_path_code 0 /* command modifier for `\&{doublepath}' */
+@d contour_code 1 /* command modifier for `\&{contour}' */
+@d also_code 2 /* command modifier for `\&{also}' */
+
+@ Pre and postscripts need two new identifiers:
+
+@d with_mp_pre_script 11
+@d with_mp_post_script 13
+
+@<Put each...@>=
+mp_primitive(mp, "doublepath",thing_to_add,double_path_code);
+@:double_path_}{\&{doublepath} primitive@>
+mp_primitive(mp, "contour",thing_to_add,contour_code);
+@:contour_}{\&{contour} primitive@>
+mp_primitive(mp, "also",thing_to_add,also_code);
+@:also_}{\&{also} primitive@>
+mp_primitive(mp, "withpen",with_option,mp_pen_type);
+@:with_pen_}{\&{withpen} primitive@>
+mp_primitive(mp, "dashed",with_option,mp_picture_type);
+@:dashed_}{\&{dashed} primitive@>
+mp_primitive(mp, "withprescript",with_option,with_mp_pre_script);
+@:with_mp_pre_script_}{\&{withprescript} primitive@>
+mp_primitive(mp, "withpostscript",with_option,with_mp_post_script);
+@:with_mp_post_script_}{\&{withpostscript} primitive@>
+mp_primitive(mp, "withoutcolor",with_option,mp_no_model);
+@:with_color_}{\&{withoutcolor} primitive@>
+mp_primitive(mp, "withgreyscale",with_option,mp_grey_model);
+@:with_color_}{\&{withgreyscale} primitive@>
+mp_primitive(mp, "withcolor",with_option,mp_uninitialized_model);
+@:with_color_}{\&{withcolor} primitive@>
+/* \&{withrgbcolor} is an alias for \&{withcolor} */
+mp_primitive(mp, "withrgbcolor",with_option,mp_rgb_model);
+@:with_color_}{\&{withrgbcolor} primitive@>
+mp_primitive(mp, "withcmykcolor",with_option,mp_cmyk_model);
+@:with_color_}{\&{withcmykcolor} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case thing_to_add:
+ if ( m==contour_code ) mp_print(mp, "contour");
+ else if ( m==double_path_code ) mp_print(mp, "doublepath");
+ else mp_print(mp, "also");
+ break;
+case with_option:
+ if ( m==mp_pen_type ) mp_print(mp, "withpen");
+ else if ( m==with_mp_pre_script ) mp_print(mp, "withprescript");
+ else if ( m==with_mp_post_script ) mp_print(mp, "withpostscript");
+ else if ( m==mp_no_model ) mp_print(mp, "withoutcolor");
+ else if ( m==mp_rgb_model ) mp_print(mp, "withrgbcolor");
+ else if ( m==mp_uninitialized_model ) mp_print(mp, "withcolor");
+ else if ( m==mp_cmyk_model ) mp_print(mp, "withcmykcolor");
+ else if ( m==mp_grey_model ) mp_print(mp, "withgreyscale");
+ else mp_print(mp, "dashed");
+ break;
+
+@ The |scan_with_list| procedure parses a $\langle$with list$\rangle$ and
+updates the list of graphical objects starting at |p|. Each $\langle$with
+clause$\rangle$ updates all graphical objects whose |type| is compatible.
+Other objects are ignored.
+
+@<Declare action procedures for use by |do_statement|@>=
+static void mp_scan_with_list (MP mp,pointer p) ;
+
+@ @c void mp_scan_with_list (MP mp,pointer p) {
+ quarterword t; /* |cur_mod| of the |with_option| (should match |cur_type|) */
+ pointer q; /* for list manipulation */
+ unsigned old_setting; /* saved |selector| setting */
+ pointer k; /* for finding the near-last item in a list */
+ str_number s; /* for string cleanup after combining */
+ pointer cp,pp,dp,ap,bp;
+ /* objects being updated; |void| initially; |null| to suppress update */
+ cp=mp_void; pp=mp_void; dp=mp_void; ap=mp_void; bp=mp_void;
+ k=0;
+ while ( mp->cur_cmd==with_option ){
+ t=mp->cur_mod;
+ mp_get_x_next(mp);
+ if ( t!=mp_no_model ) mp_scan_expression(mp);
+ if (((t==with_mp_pre_script)&&(mp->cur_type!=mp_string_type))||
+ ((t==with_mp_post_script)&&(mp->cur_type!=mp_string_type))||
+ ((t==mp_uninitialized_model)&&
+ ((mp->cur_type!=mp_cmykcolor_type)&&(mp->cur_type!=mp_color_type)
+ &&(mp->cur_type!=mp_known)&&(mp->cur_type!=mp_boolean_type)))||
+ ((t==mp_cmyk_model)&&(mp->cur_type!=mp_cmykcolor_type))||
+ ((t==mp_rgb_model)&&(mp->cur_type!=mp_color_type))||
+ ((t==mp_grey_model)&&(mp->cur_type!=mp_known))||
+ ((t==mp_pen_type)&&(mp->cur_type!=t))||
+ ((t==mp_picture_type)&&(mp->cur_type!=t)) ) {
+ @<Complain about improper type@>;
+ } else if ( t==mp_uninitialized_model ) {
+ if ( cp==mp_void ) @<Make |cp| a colored object in object list~|p|@>;
+ if ( cp!=null )
+ @<Transfer a color from the current expression to object~|cp|@>;
+ mp_flush_cur_exp(mp, 0);
+ } else if ( t==mp_rgb_model ) {
+ if ( cp==mp_void ) @<Make |cp| a colored object in object list~|p|@>;
+ if ( cp!=null )
+ @<Transfer a rgbcolor from the current expression to object~|cp|@>;
+ mp_flush_cur_exp(mp, 0);
+ } else if ( t==mp_cmyk_model ) {
+ if ( cp==mp_void ) @<Make |cp| a colored object in object list~|p|@>;
+ if ( cp!=null )
+ @<Transfer a cmykcolor from the current expression to object~|cp|@>;
+ mp_flush_cur_exp(mp, 0);
+ } else if ( t==mp_grey_model ) {
+ if ( cp==mp_void ) @<Make |cp| a colored object in object list~|p|@>;
+ if ( cp!=null )
+ @<Transfer a greyscale from the current expression to object~|cp|@>;
+ mp_flush_cur_exp(mp, 0);
+ } else if ( t==mp_no_model ) {
+ if ( cp==mp_void ) @<Make |cp| a colored object in object list~|p|@>;
+ if ( cp!=null )
+ @<Transfer a noncolor from the current expression to object~|cp|@>;
+ } else if ( t==mp_pen_type ) {
+ if ( pp==mp_void ) @<Make |pp| an object in list~|p| that needs a pen@>;
+ if ( pp!=null ) {
+ if ( mp_pen_p(pp)!=null ) mp_toss_knot_list(mp, mp_pen_p(pp));
+ mp_pen_p(pp)=mp->cur_exp; mp->cur_type=mp_vacuous;
+ }
+ } else if ( t==with_mp_pre_script ) {
+ if ( ap==mp_void )
+ ap=p;
+ while ( (ap!=null)&&(! has_color(ap)) )
+ ap=mp_link(ap);
+ if ( ap!=null ) {
+ if ( mp_pre_script(ap)!=null ) { /* build a new,combined string */
+ s=mp_pre_script(ap);
+ old_setting=mp->selector;
+ mp->selector=new_string;
+ str_room(length(mp_pre_script(ap))+length(mp->cur_exp)+2);
+ mp_print_str(mp, mp->cur_exp);
+ append_char(13); /* a forced \ps\ newline */
+ mp_print_str(mp, mp_pre_script(ap));
+ mp_pre_script(ap)=mp_make_string(mp);
+ delete_str_ref(s);
+ mp->selector=old_setting;
+ } else {
+ mp_pre_script(ap)=mp->cur_exp;
+ }
+ mp->cur_type=mp_vacuous;
+ }
+ } else if ( t==with_mp_post_script ) {
+ if ( bp==mp_void )
+ k=p;
+ bp=k;
+ while ( mp_link(k)!=null ) {
+ k=mp_link(k);
+ if ( has_color(k) ) bp=k;
+ }
+ if ( bp!=null ) {
+ if ( mp_post_script(bp)!=null ) {
+ s=mp_post_script(bp);
+ old_setting=mp->selector;
+ mp->selector=new_string;
+ str_room(length(mp_post_script(bp))+length(mp->cur_exp)+2);
+ mp_print_str(mp, mp_post_script(bp));
+ append_char(13); /* a forced \ps\ newline */
+ mp_print_str(mp, mp->cur_exp);
+ mp_post_script(bp)=mp_make_string(mp);
+ delete_str_ref(s);
+ mp->selector=old_setting;
+ } else {
+ mp_post_script(bp)=mp->cur_exp;
+ }
+ mp->cur_type=mp_vacuous;
+ }
+ } else {
+ if ( dp==mp_void ) {
+ @<Make |dp| a stroked node in list~|p|@>;
+ }
+ if ( dp!=null ) {
+ if ( mp_dash_p(dp)!=null ) delete_edge_ref(mp_dash_p(dp));
+ mp_dash_p(dp)=mp_make_dashes(mp, mp->cur_exp);
+ dash_scale(dp)=unity;
+ mp->cur_type=mp_vacuous;
+ }
+ }
+ }
+ @<Copy the information from objects |cp|, |pp|, and |dp| into the rest
+ of the list@>;
+}
+
+@ @<Complain about improper type@>=
+{ exp_err("Improper type");
+@.Improper type@>
+help2("Next time say `withpen <known pen expression>';",
+ "I'll ignore the bad `with' clause and look for another.");
+if ( t==with_mp_pre_script )
+ mp->help_line[1]="Next time say `withprescript <known string expression>';";
+else if ( t==with_mp_post_script )
+ mp->help_line[1]="Next time say `withpostscript <known string expression>';";
+else if ( t==mp_picture_type )
+ mp->help_line[1]="Next time say `dashed <known picture expression>';";
+else if ( t==mp_uninitialized_model )
+ mp->help_line[1]="Next time say `withcolor <known color expression>';";
+else if ( t==mp_rgb_model )
+ mp->help_line[1]="Next time say `withrgbcolor <known color expression>';";
+else if ( t==mp_cmyk_model )
+ mp->help_line[1]="Next time say `withcmykcolor <known cmykcolor expression>';";
+else if ( t==mp_grey_model )
+ mp->help_line[1]="Next time say `withgreyscale <known numeric expression>';";;
+mp_put_get_flush_error(mp, 0);
+}
+
+@ Forcing the color to be between |0| and |unity| here guarantees that no
+picture will ever contain a color outside the legal range for \ps\ graphics.
+
+@<Transfer a color from the current expression to object~|cp|@>=
+{ if ( mp->cur_type==mp_color_type )
+ @<Transfer a rgbcolor from the current expression to object~|cp|@>
+else if ( mp->cur_type==mp_cmykcolor_type )
+ @<Transfer a cmykcolor from the current expression to object~|cp|@>
+else if ( mp->cur_type==mp_known )
+ @<Transfer a greyscale from the current expression to object~|cp|@>
+else if ( mp->cur_exp==false_code )
+ @<Transfer a noncolor from the current expression to object~|cp|@>;
+}
+
+@ @<Transfer a rgbcolor from the current expression to object~|cp|@>=
+{ q=value(mp->cur_exp);
+cyan_val(cp)=0;
+magenta_val(cp)=0;
+yellow_val(cp)=0;
+black_val(cp)=0;
+red_val(cp)=value(red_part_loc(q));
+green_val(cp)=value(green_part_loc(q));
+blue_val(cp)=value(blue_part_loc(q));
+mp_color_model(cp)=mp_rgb_model;
+if ( red_val(cp)<0 ) red_val(cp)=0;
+if ( green_val(cp)<0 ) green_val(cp)=0;
+if ( blue_val(cp)<0 ) blue_val(cp)=0;
+if ( red_val(cp)>unity ) red_val(cp)=unity;
+if ( green_val(cp)>unity ) green_val(cp)=unity;
+if ( blue_val(cp)>unity ) blue_val(cp)=unity;
+}
+
+@ @<Transfer a cmykcolor from the current expression to object~|cp|@>=
+{ q=value(mp->cur_exp);
+cyan_val(cp)=value(cyan_part_loc(q));
+magenta_val(cp)=value(magenta_part_loc(q));
+yellow_val(cp)=value(yellow_part_loc(q));
+black_val(cp)=value(black_part_loc(q));
+mp_color_model(cp)=mp_cmyk_model;
+if ( cyan_val(cp)<0 ) cyan_val(cp)=0;
+if ( magenta_val(cp)<0 ) magenta_val(cp)=0;
+if ( yellow_val(cp)<0 ) yellow_val(cp)=0;
+if ( black_val(cp)<0 ) black_val(cp)=0;
+if ( cyan_val(cp)>unity ) cyan_val(cp)=unity;
+if ( magenta_val(cp)>unity ) magenta_val(cp)=unity;
+if ( yellow_val(cp)>unity ) yellow_val(cp)=unity;
+if ( black_val(cp)>unity ) black_val(cp)=unity;
+}
+
+@ @<Transfer a greyscale from the current expression to object~|cp|@>=
+{ q=mp->cur_exp;
+cyan_val(cp)=0;
+magenta_val(cp)=0;
+yellow_val(cp)=0;
+black_val(cp)=0;
+grey_val(cp)=q;
+mp_color_model(cp)=mp_grey_model;
+if ( grey_val(cp)<0 ) grey_val(cp)=0;
+if ( grey_val(cp)>unity ) grey_val(cp)=unity;
+}
+
+@ @<Transfer a noncolor from the current expression to object~|cp|@>=
+{
+cyan_val(cp)=0;
+magenta_val(cp)=0;
+yellow_val(cp)=0;
+black_val(cp)=0;
+grey_val(cp)=0;
+mp_color_model(cp)=mp_no_model;
+}
+
+@ @<Make |cp| a colored object in object list~|p|@>=
+{ cp=p;
+ while ( cp!=null ){
+ if ( has_color(cp) ) break;
+ cp=mp_link(cp);
+ }
+}
+
+@ @<Make |pp| an object in list~|p| that needs a pen@>=
+{ pp=p;
+ while ( pp!=null ) {
+ if ( has_pen(pp) ) break;
+ pp=mp_link(pp);
+ }
+}
+
+@ @<Make |dp| a stroked node in list~|p|@>=
+{ dp=p;
+ while ( dp!=null ) {
+ if ( mp_type(dp)==mp_stroked_code ) break;
+ dp=mp_link(dp);
+ }
+}
+
+@ @<Copy the information from objects |cp|, |pp|, and |dp| into...@>=
+@<Copy |cp|'s color into the colored objects linked to~|cp|@>;
+if ( pp>mp_void ) {
+ @<Copy |mp_pen_p(pp)| into stroked and filled nodes linked to |pp|@>;
+}
+if ( dp>mp_void ) {
+ @<Make stroked nodes linked to |dp| refer to |mp_dash_p(dp)|@>;
+}
+
+
+@ @<Copy |cp|'s color into the colored objects linked to~|cp|@>=
+{ q=mp_link(cp);
+ while ( q!=null ) {
+ if ( has_color(q) ) {
+ red_val(q)=red_val(cp);
+ green_val(q)=green_val(cp);
+ blue_val(q)=blue_val(cp);
+ black_val(q)=black_val(cp);
+ mp_color_model(q)=mp_color_model(cp);
+ }
+ q=mp_link(q);
+ }
+}
+
+@ @<Copy |mp_pen_p(pp)| into stroked and filled nodes linked to |pp|@>=
+{ q=mp_link(pp);
+ while ( q!=null ) {
+ if ( has_pen(q) ) {
+ if ( mp_pen_p(q)!=null ) mp_toss_knot_list(mp, mp_pen_p(q));
+ mp_pen_p(q)=copy_pen(mp_pen_p(pp));
+ }
+ q=mp_link(q);
+ }
+}
+
+@ @<Make stroked nodes linked to |dp| refer to |mp_dash_p(dp)|@>=
+{ q=mp_link(dp);
+ while ( q!=null ) {
+ if ( mp_type(q)==mp_stroked_code ) {
+ if ( mp_dash_p(q)!=null ) delete_edge_ref(mp_dash_p(q));
+ mp_dash_p(q)=mp_dash_p(dp);
+ dash_scale(q)=unity;
+ if ( mp_dash_p(q)!=null ) add_edge_ref(mp_dash_p(q));
+ }
+ q=mp_link(q);
+ }
+}
+
+@ One of the things we need to do when we've parsed an \&{addto} or
+similar command is find the header of a supposed \&{picture} variable, given
+a token list for that variable. Since the edge structure is about to be
+updated, we use |private_edges| to make sure that this is possible.
+
+@<Declare action procedures for use by |do_statement|@>=
+static pointer mp_find_edges_var (MP mp, pointer t) ;
+
+@ @c pointer mp_find_edges_var (MP mp, pointer t) {
+ pointer p;
+ pointer cur_edges; /* the return value */
+ p=mp_find_variable(mp, t); cur_edges=null;
+ if ( p==null ) {
+ mp_obliterated(mp, t); mp_put_get_error(mp);
+ } else if ( mp_type(p)!=mp_picture_type ) {
+ print_err("Variable "); mp_show_token_list(mp, t,null,1000,0);
+@.Variable x is the wrong type@>
+ mp_print(mp, " is the wrong type (");
+ mp_print_type(mp, mp_type(p)); mp_print_char(mp, xord(')'));
+ help2("I was looking for a \"known\" picture variable.",
+ "So I'll not change anything just now.");
+ mp_put_get_error(mp);
+ } else {
+ value(p)=mp_private_edges(mp, value(p));
+ cur_edges=value(p);
+ }
+ mp_flush_node_list(mp, t);
+ return cur_edges;
+}
+
+@ @<Cases of |do_statement|...@>=
+case add_to_command: mp_do_add_to(mp); break;
+case bounds_command:mp_do_bounds(mp); break;
+
+@ @<Put each...@>=
+mp_primitive(mp, "clip",bounds_command,mp_start_clip_code);
+@:clip_}{\&{clip} primitive@>
+mp_primitive(mp, "setbounds",bounds_command,mp_start_bounds_code);
+@:set_bounds_}{\&{setbounds} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case bounds_command:
+ if ( m==mp_start_clip_code ) mp_print(mp, "clip");
+ else mp_print(mp, "setbounds");
+ break;
+
+@ The following function parses the beginning of an \&{addto} or \&{clip}
+command: it expects a variable name followed by a token with |cur_cmd=sep|
+and then an expression. The function returns the token list for the variable
+and stores the command modifier for the separator token in the global variable
+|last_add_type|. We must be careful because this variable might get overwritten
+any time we call |get_x_next|.
+
+@<Glob...@>=
+quarterword last_add_type;
+ /* command modifier that identifies the last \&{addto} command */
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static pointer mp_start_draw_cmd (MP mp,quarterword sep) ;
+
+@ @c pointer mp_start_draw_cmd (MP mp,quarterword sep) {
+ pointer lhv; /* variable to add to left */
+ quarterword add_type=0; /* value to be returned in |last_add_type| */
+ lhv=null;
+ mp_get_x_next(mp); mp->var_flag=sep; mp_scan_primary(mp);
+ if ( mp->cur_type!=mp_token_list ) {
+ @<Abandon edges command because there's no variable@>;
+ } else {
+ lhv=mp->cur_exp; add_type=mp->cur_mod;
+ mp->cur_type=mp_vacuous; mp_get_x_next(mp); mp_scan_expression(mp);
+ }
+ mp->last_add_type=add_type;
+ return lhv;
+}
+
+@ @<Abandon edges command because there's no variable@>=
+{ exp_err("Not a suitable variable");
+@.Not a suitable variable@>
+ help4("At this point I needed to see the name of a picture variable.",
+ "(Or perhaps you have indeed presented me with one; I might",
+ "have missed it, if it wasn't followed by the proper token.)",
+ "So I'll not change anything just now.");
+ mp_put_get_flush_error(mp, 0);
+}
+
+@ Here is an example of how to use |start_draw_cmd|.
+
+@<Declare action procedures for use by |do_statement|@>=
+static void mp_do_bounds (MP mp) ;
+
+@ @c void mp_do_bounds (MP mp) {
+ pointer lhv,lhe; /* variable on left, the corresponding edge structure */
+ pointer p; /* for list manipulation */
+ integer m; /* initial value of |cur_mod| */
+ m=mp->cur_mod;
+ lhv=mp_start_draw_cmd(mp, to_token);
+ if ( lhv!=null ) {
+ lhe=mp_find_edges_var(mp, lhv);
+ if ( lhe==null ) {
+ mp_flush_cur_exp(mp, 0);
+ } else if ( mp->cur_type!=mp_path_type ) {
+ exp_err("Improper `clip'");
+@.Improper `addto'@>
+ help2("This expression should have specified a known path.",
+ "So I'll not change anything just now.");
+ mp_put_get_flush_error(mp, 0);
+ } else if ( mp_left_type(mp->cur_exp)==mp_endpoint ) {
+ @<Complain about a non-cycle@>;
+ } else {
+ @<Make |cur_exp| into a \&{setbounds} or clipping path and add it to |lhe|@>;
+ }
+ }
+}
+
+@ @<Complain about a non-cycle@>=
+{ print_err("Not a cycle");
+@.Not a cycle@>
+ help2("That contour should have ended with `..cycle' or `&cycle'.",
+ "So I'll not change anything just now."); mp_put_get_error(mp);
+}
+
+@ @<Make |cur_exp| into a \&{setbounds} or clipping path and add...@>=
+{ p=mp_new_bounds_node(mp, mp->cur_exp,m);
+ mp_link(p)=mp_link(dummy_loc(lhe));
+ mp_link(dummy_loc(lhe))=p;
+ if ( obj_tail(lhe)==dummy_loc(lhe) ) obj_tail(lhe)=p;
+ p=mp_get_node(mp, mp->gr_object_size[stop_type(m)]);
+ mp_type(p)=stop_type(m);
+ mp_link(obj_tail(lhe))=p;
+ obj_tail(lhe)=p;
+ mp_init_bbox(mp, lhe);
+}
+
+@ The |do_add_to| procedure is a little like |do_clip| but there are a lot more
+cases to deal with.
+
+@<Declare action procedures for use by |do_statement|@>=
+static void mp_do_add_to (MP mp) ;
+
+@ @c void mp_do_add_to (MP mp) {
+ pointer lhv,lhe; /* variable on left, the corresponding edge structure */
+ pointer p; /* the graphical object or list for |scan_with_list| to update */
+ pointer e; /* an edge structure to be merged */
+ quarterword add_type; /* |also_code|, |contour_code|, or |double_path_code| */
+ lhv=mp_start_draw_cmd(mp, thing_to_add); add_type=mp->last_add_type;
+ if ( lhv!=null ) {
+ if ( add_type==also_code ) {
+ @<Make sure the current expression is a suitable picture and set |e| and |p|
+ appropriately@>;
+ } else {
+ @<Create a graphical object |p| based on |add_type| and the current
+ expression@>;
+ }
+ mp_scan_with_list(mp, p);
+ @<Use |p|, |e|, and |add_type| to augment |lhv| as requested@>;
+ }
+}
+
+@ Setting |p:=null| causes the $\langle$with list$\rangle$ to be ignored;
+setting |e:=null| prevents anything from being added to |lhe|.
+
+@ @<Make sure the current expression is a suitable picture and set |e|...@>=
+{
+ p=null; e=null;
+ if ( mp->cur_type!=mp_picture_type ) {
+ exp_err("Improper `addto'");
+@.Improper `addto'@>
+ help2("This expression should have specified a known picture.",
+ "So I'll not change anything just now.");
+ mp_put_get_flush_error(mp, 0);
+ } else {
+ e=mp_private_edges(mp, mp->cur_exp); mp->cur_type=mp_vacuous;
+ p=mp_link(dummy_loc(e));
+ }
+}
+
+@ In this case |add_type<>also_code| so setting |p:=null| suppresses future
+attempts to add to the edge structure.
+
+@<Create a graphical object |p| based on |add_type| and the current...@>=
+{ e=null; p=null;
+ if ( mp->cur_type==mp_pair_type ) mp_pair_to_path(mp);
+ if ( mp->cur_type!=mp_path_type ) {
+ exp_err("Improper `addto'");
+@.Improper `addto'@>
+ help2("This expression should have specified a known path.",
+ "So I'll not change anything just now.");
+ mp_put_get_flush_error(mp, 0);
+ } else if ( add_type==contour_code ) {
+ if ( mp_left_type(mp->cur_exp)==mp_endpoint ) {
+ @<Complain about a non-cycle@>;
+ } else {
+ p=mp_new_fill_node(mp, mp->cur_exp);
+ mp->cur_type=mp_vacuous;
+ }
+ } else {
+ p=mp_new_stroked_node(mp, mp->cur_exp);
+ mp->cur_type=mp_vacuous;
+ }
+}
+
+@ @<Use |p|, |e|, and |add_type| to augment |lhv| as requested@>=
+lhe=mp_find_edges_var(mp, lhv);
+if ( lhe==null ) {
+ if ( (e==null)&&(p!=null) ) e=mp_toss_gr_object(mp, p);
+ if ( e!=null ) delete_edge_ref(e);
+} else if ( add_type==also_code ) {
+ if ( e!=null ) {
+ @<Merge |e| into |lhe| and delete |e|@>;
+ } else {
+ do_nothing;
+ }
+} else if ( p!=null ) {
+ mp_link(obj_tail(lhe))=p;
+ obj_tail(lhe)=p;
+ if ( add_type==double_path_code )
+ if ( mp_pen_p(p)==null )
+ mp_pen_p(p)=mp_get_pen_circle(mp, 0);
+}
+
+@ @<Merge |e| into |lhe| and delete |e|@>=
+{ if ( mp_link(dummy_loc(e))!=null ) {
+ mp_link(obj_tail(lhe))=mp_link(dummy_loc(e));
+ obj_tail(lhe)=obj_tail(e);
+ obj_tail(e)=dummy_loc(e);
+ mp_link(dummy_loc(e))=null;
+ mp_flush_dash_list(mp, lhe);
+ }
+ mp_toss_edges(mp, e);
+}
+
+@ @<Cases of |do_statement|...@>=
+case ship_out_command: mp_do_ship_out(mp); break;
+
+@ @<Declare action procedures for use by |do_statement|@>=
+@<Declare the \ps\ output procedures@>
+static void mp_do_ship_out (MP mp) ;
+
+@ @c void mp_do_ship_out (MP mp) {
+ integer c; /* the character code */
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_picture_type ) {
+ @<Complain that it's not a known picture@>;
+ } else {
+ c=mp_round_unscaled(mp, mp->internal[mp_char_code]) % 256;
+ if ( c<0 ) c=c+256;
+ @<Store the width information for character code~|c|@>;
+ mp_ship_out(mp, mp->cur_exp);
+ mp_flush_cur_exp(mp, 0);
+ }
+}
+
+@ @<Complain that it's not a known picture@>=
+{
+ exp_err("Not a known picture");
+ help1("I can only output known pictures.");
+ mp_put_get_flush_error(mp, 0);
+}
+
+@ The \&{everyjob} command simply assigns a nonzero value to the global variable
+|start_sym|.
+
+@<Cases of |do_statement|...@>=
+case every_job_command:
+ mp_get_symbol(mp); mp->start_sym=mp->cur_sym; mp_get_x_next(mp);
+ break;
+
+@ @<Glob...@>=
+halfword start_sym; /* a symbolic token to insert at beginning of job */
+
+@ @<Set init...@>=
+mp->start_sym=0;
+
+@ Finally, we have only the ``message'' commands remaining.
+
+@d message_code 0
+@d err_message_code 1
+@d err_help_code 2
+@d filename_template_code 3
+@d print_with_leading_zeroes(A) g = mp->pool_ptr;
+ mp_print_int(mp, (A)); g = mp->pool_ptr-g;
+ if ( f>g ) {
+ mp->pool_ptr = mp->pool_ptr - g;
+ while ( f>g ) {
+ mp_print_char(mp, xord('0'));
+ decr(f);
+ };
+ mp_print_int(mp, (A));
+ };
+ f = 0
+
+@<Put each...@>=
+mp_primitive(mp, "message",message_command,message_code);
+@:message_}{\&{message} primitive@>
+mp_primitive(mp, "errmessage",message_command,err_message_code);
+@:err_message_}{\&{errmessage} primitive@>
+mp_primitive(mp, "errhelp",message_command,err_help_code);
+@:err_help_}{\&{errhelp} primitive@>
+mp_primitive(mp, "filenametemplate",message_command,filename_template_code);
+@:filename_template_}{\&{filenametemplate} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case message_command:
+ if ( m<err_message_code ) mp_print(mp, "message");
+ else if ( m==err_message_code ) mp_print(mp, "errmessage");
+ else if ( m==filename_template_code ) mp_print(mp, "filenametemplate");
+ else mp_print(mp, "errhelp");
+ break;
+
+@ @<Cases of |do_statement|...@>=
+case message_command: mp_do_message(mp); break;
+
+@ @<Declare action procedures for use by |do_statement|@>=
+@<Declare a procedure called |no_string_err|@>
+static void mp_do_message (MP mp) ;
+
+@
+@c void mp_do_message (MP mp) {
+ int m; /* the type of message */
+ m=mp->cur_mod; mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_string_type )
+ mp_no_string_err(mp, "A message should be a known string expression.");
+ else {
+ switch (m) {
+ case message_code:
+ mp_print_nl(mp, ""); mp_print_str(mp, mp->cur_exp);
+ break;
+ case err_message_code:
+ @<Print string |cur_exp| as an error message@>;
+ break;
+ case err_help_code:
+ @<Save string |cur_exp| as the |err_help|@>;
+ break;
+ case filename_template_code:
+ @<Save the filename template@>;
+ break;
+ } /* there are no other cases */
+ }
+ mp_flush_cur_exp(mp, 0);
+}
+
+@ @<Declare a procedure called |no_string_err|@>=
+static void mp_no_string_err (MP mp, const char *s) {
+ exp_err("Not a string");
+@.Not a string@>
+ help1(s);
+ mp_put_get_error(mp);
+}
+
+@ The global variable |err_help| is zero when the user has most recently
+given an empty help string, or if none has ever been given.
+
+@<Save string |cur_exp| as the |err_help|@>=
+{
+ if ( mp->err_help!=0 ) delete_str_ref(mp->err_help);
+ if ( length(mp->cur_exp)==0 ) mp->err_help=0;
+ else { mp->err_help=mp->cur_exp; add_str_ref(mp->err_help); }
+}
+
+@ If \&{errmessage} occurs often in |mp_scroll_mode|, without user-defined
+\&{errhelp}, we don't want to give a long help message each time. So we
+give a verbose explanation only once.
+
+@<Glob...@>=
+boolean long_help_seen; /* has the long \.{\\errmessage} help been used? */
+
+@ @<Set init...@>=mp->long_help_seen=false;
+
+@ @<Print string |cur_exp| as an error message@>=
+{
+ print_err(""); mp_print_str(mp, mp->cur_exp);
+ if ( mp->err_help!=0 ) {
+ mp->use_err_help=true;
+ } else if ( mp->long_help_seen ) {
+ help1("(That was another `errmessage'.)") ;
+ } else {
+ if ( mp->interaction<mp_error_stop_mode ) mp->long_help_seen=true;
+ help4("This error message was generated by an `errmessage'",
+ "command, so I can\'t give any explicit help.",
+ "Pretend that you're Miss Marple: Examine all clues,",
+@^Marple, Jane@>
+ "and deduce the truth by inspired guesses.");
+ }
+ mp_put_get_error(mp); mp->use_err_help=false;
+}
+
+@ @<Cases of |do_statement|...@>=
+case write_command: mp_do_write(mp); break;
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_do_write (MP mp) ;
+
+@ @c void mp_do_write (MP mp) {
+ str_number t; /* the line of text to be written */
+ write_index n,n0; /* for searching |wr_fname| and |wr_file| arrays */
+ unsigned old_setting; /* for saving |selector| during output */
+ mp_get_x_next(mp);
+ mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_string_type ) {
+ mp_no_string_err(mp, "The text to be written should be a known string expression");
+ } else if ( mp->cur_cmd!=to_token ) {
+ print_err("Missing `to' clause");
+ help1("A write command should end with `to <filename>'");
+ mp_put_get_error(mp);
+ } else {
+ t=mp->cur_exp; mp->cur_type=mp_vacuous;
+ mp_get_x_next(mp);
+ mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_string_type )
+ mp_no_string_err(mp, "I can\'t write to that file name. It isn't a known string");
+ else {
+ @<Write |t| to the file named by |cur_exp|@>;
+ }
+ delete_str_ref(t);
+ }
+ mp_flush_cur_exp(mp, 0);
+}
+
+@ @<Write |t| to the file named by |cur_exp|@>=
+{
+ @<Find |n| where |wr_fname[n]=cur_exp| and call |open_write_file| if
+ |cur_exp| must be inserted@>;
+ if ( mp_str_vs_str(mp, t,mp->eof_line)==0 ) {
+ @<Record the end of file on |wr_file[n]|@>;
+ } else {
+ old_setting=mp->selector;
+ mp->selector=n+write_file;
+ mp_print_str(mp, t); mp_print_ln(mp);
+ mp->selector = old_setting;
+ }
+}
+
+@ @<Find |n| where |wr_fname[n]=cur_exp| and call |open_write_file| if...@>=
+{
+ char *fn = str(mp->cur_exp);
+ n=mp->write_files;
+ n0=mp->write_files;
+ while (mp_xstrcmp(fn,mp->wr_fname[n])!=0) {
+ if ( n==0 ) { /* bottom reached */
+ if ( n0==mp->write_files ) {
+ if ( mp->write_files<mp->max_write_files ) {
+ incr(mp->write_files);
+ } else {
+ void **wr_file;
+ char **wr_fname;
+ write_index l,k;
+ l = mp->max_write_files + (mp->max_write_files/4);
+ wr_file = xmalloc((l+1),sizeof(void *));
+ wr_fname = xmalloc((l+1),sizeof(char *));
+ for (k=0;k<=l;k++) {
+ if (k<=mp->max_write_files) {
+ wr_file[k]=mp->wr_file[k];
+ wr_fname[k]=mp->wr_fname[k];
+ } else {
+ wr_file[k]=0;
+ wr_fname[k]=NULL;
+ }
+ }
+ xfree(mp->wr_file); xfree(mp->wr_fname);
+ mp->max_write_files = l;
+ mp->wr_file = wr_file;
+ mp->wr_fname = wr_fname;
+ }
+ }
+ n=n0;
+ mp_open_write_file(mp, fn ,n);
+ } else {
+ decr(n);
+ if ( mp->wr_fname[n]==NULL ) n0=n;
+ }
+ }
+}
+
+@ @<Record the end of file on |wr_file[n]|@>=
+{ (mp->close_file)(mp,mp->wr_file[n]);
+ xfree(mp->wr_fname[n]);
+ if ( n==mp->write_files-1 ) mp->write_files=n;
+}
+
+
+@* \[42] Writing font metric data.
+\TeX\ gets its knowledge about fonts from font metric files, also called
+\.{TFM} files; the `\.T' in `\.{TFM}' stands for \TeX,
+but other programs know about them too. One of \MP's duties is to
+write \.{TFM} files so that the user's fonts can readily be
+applied to typesetting.
+@:TFM files}{\.{TFM} files@>
+@^font metric files@>
+
+The information in a \.{TFM} file appears in a sequence of 8-bit bytes.
+Since the number of bytes is always a multiple of~4, we could
+also regard the file as a sequence of 32-bit words, but \MP\ uses the
+byte interpretation. The format of \.{TFM} files was designed by
+Lyle Ramshaw in 1980. The intent is to convey a lot of different kinds
+@^Ramshaw, Lyle Harold@>
+of information in a compact but useful form.
+
+@<Glob...@>=
+void * tfm_file; /* the font metric output goes here */
+char * metric_file_name; /* full name of the font metric file */
+
+@ The first 24 bytes (6 words) of a \.{TFM} file contain twelve 16-bit
+integers that give the lengths of the various subsequent portions
+of the file. These twelve integers are, in order:
+$$\vbox{\halign{\hfil#&$\null=\null$#\hfil\cr
+|lf|&length of the entire file, in words;\cr
+|lh|&length of the header data, in words;\cr
+|bc|&smallest character code in the font;\cr
+|ec|&largest character code in the font;\cr
+|nw|&number of words in the width table;\cr
+|nh|&number of words in the height table;\cr
+|nd|&number of words in the depth table;\cr
+|ni|&number of words in the italic correction table;\cr
+|nl|&number of words in the lig/kern table;\cr
+|nk|&number of words in the kern table;\cr
+|ne|&number of words in the extensible character table;\cr
+|np|&number of font parameter words.\cr}}$$
+They are all nonnegative and less than $2^{15}$. We must have |bc-1<=ec<=255|,
+|ne<=256|, and
+$$\hbox{|lf=6+lh+(ec-bc+1)+nw+nh+nd+ni+nl+nk+ne+np|.}$$
+Note that a font may contain as many as 256 characters (if |bc=0| and |ec=255|),
+and as few as 0 characters (if |bc=ec+1|).
+
+Incidentally, when two or more 8-bit bytes are combined to form an integer of
+16 or more bits, the most significant bytes appear first in the file.
+This is called BigEndian order.
+@^BigEndian order@>
+
+@ The rest of the \.{TFM} file may be regarded as a sequence of ten data
+arrays.
+
+The most important data type used here is a |fix_word|, which is
+a 32-bit representation of a binary fraction. A |fix_word| is a signed
+quantity, with the two's complement of the entire word used to represent
+negation. Of the 32 bits in a |fix_word|, exactly 12 are to the left of the
+binary point; thus, the largest |fix_word| value is $2048-2^{-20}$, and
+the smallest is $-2048$. We will see below, however, that all but two of
+the |fix_word| values must lie between $-16$ and $+16$.
+
+@ The first data array is a block of header information, which contains
+general facts about the font. The header must contain at least two words,
+|header[0]| and |header[1]|, whose meaning is explained below. Additional
+header information of use to other software routines might also be
+included, and \MP\ will generate it if the \.{headerbyte} command occurs.
+For example, 16 more words of header information are in use at the Xerox
+Palo Alto Research Center; the first ten specify the character coding
+scheme used (e.g., `\.{XEROX TEXT}' or `\.{TEX MATHSY}'), the next five
+give the font family name (e.g., `\.{HELVETICA}' or `\.{CMSY}'), and the
+last gives the ``face byte.''
+
+\yskip\hang|header[0]| is a 32-bit check sum that \MP\ will copy into
+the \.{GF} output file. This helps ensure consistency between files,
+since \TeX\ records the check sums from the \.{TFM}'s it reads, and these
+should match the check sums on actual fonts that are used. The actual
+relation between this check sum and the rest of the \.{TFM} file is not
+important; the check sum is simply an identification number with the
+property that incompatible fonts almost always have distinct check sums.
+@^check sum@>
+
+\yskip\hang|header[1]| is a |fix_word| containing the design size of the
+font, in units of \TeX\ points. This number must be at least 1.0; it is
+fairly arbitrary, but usually the design size is 10.0 for a ``10 point''
+font, i.e., a font that was designed to look best at a 10-point size,
+whatever that really means. When a \TeX\ user asks for a font `\.{at}
+$\delta$ \.{pt}', the effect is to override the design size and replace it
+by $\delta$, and to multiply the $x$ and~$y$ coordinates of the points in
+the font image by a factor of $\delta$ divided by the design size. {\sl
+All other dimensions in the\/ \.{TFM} file are |fix_word|\kern-1pt\
+numbers in design-size units.} Thus, for example, the value of |param[6]|,
+which defines the \.{em} unit, is often the |fix_word| value $2^{20}=1.0$,
+since many fonts have a design size equal to one em. The other dimensions
+must be less than 16 design-size units in absolute value; thus,
+|header[1]| and |param[1]| are the only |fix_word| entries in the whole
+\.{TFM} file whose first byte might be something besides 0 or 255.
+@^design size@>
+
+@ Next comes the |char_info| array, which contains one |char_info_word|
+per character. Each word in this part of the file contains six fields
+packed into four bytes as follows.
+
+\yskip\hang first byte: |width_index| (8 bits)\par
+\hang second byte: |height_index| (4 bits) times 16, plus |depth_index|
+ (4~bits)\par
+\hang third byte: |italic_index| (6 bits) times 4, plus |tag|
+ (2~bits)\par
+\hang fourth byte: |remainder| (8 bits)\par
+\yskip\noindent
+The actual width of a character is \\{width}|[width_index]|, in design-size
+units; this is a device for compressing information, since many characters
+have the same width. Since it is quite common for many characters
+to have the same height, depth, or italic correction, the \.{TFM} format
+imposes a limit of 16 different heights, 16 different depths, and
+64 different italic corrections.
+
+Incidentally, the relation $\\{width}[0]=\\{height}[0]=\\{depth}[0]=
+\\{italic}[0]=0$ should always hold, so that an index of zero implies a
+value of zero. The |width_index| should never be zero unless the
+character does not exist in the font, since a character is valid if and
+only if it lies between |bc| and |ec| and has a nonzero |width_index|.
+
+@ The |tag| field in a |char_info_word| has four values that explain how to
+interpret the |remainder| field.
+
+\yskip\hang|tag=0| (|no_tag|) means that |remainder| is unused.\par
+\hang|tag=1| (|lig_tag|) means that this character has a ligature/kerning
+program starting at location |remainder| in the |lig_kern| array.\par
+\hang|tag=2| (|list_tag|) means that this character is part of a chain of
+characters of ascending sizes, and not the largest in the chain. The
+|remainder| field gives the character code of the next larger character.\par
+\hang|tag=3| (|ext_tag|) means that this character code represents an
+extensible character, i.e., a character that is built up of smaller pieces
+so that it can be made arbitrarily large. The pieces are specified in
+|exten[remainder]|.\par
+\yskip\noindent
+Characters with |tag=2| and |tag=3| are treated as characters with |tag=0|
+unless they are used in special circumstances in math formulas. For example,
+\TeX's \.{\\sum} operation looks for a |list_tag|, and the \.{\\left}
+operation looks for both |list_tag| and |ext_tag|.
+
+@d no_tag 0 /* vanilla character */
+@d lig_tag 1 /* character has a ligature/kerning program */
+@d list_tag 2 /* character has a successor in a charlist */
+@d ext_tag 3 /* character is extensible */
+
+@ The |lig_kern| array contains instructions in a simple programming language
+that explains what to do for special letter pairs. Each word in this array is a
+|lig_kern_command| of four bytes.
+
+\yskip\hang first byte: |skip_byte|, indicates that this is the final program
+ step if the byte is 128 or more, otherwise the next step is obtained by
+ skipping this number of intervening steps.\par
+\hang second byte: |next_char|, ``if |next_char| follows the current character,
+ then perform the operation and stop, otherwise continue.''\par
+\hang third byte: |op_byte|, indicates a ligature step if less than~128,
+ a kern step otherwise.\par
+\hang fourth byte: |remainder|.\par
+\yskip\noindent
+In a kern step, an
+additional space equal to |kern[256*(op_byte-128)+remainder]| is inserted
+between the current character and |next_char|. This amount is
+often negative, so that the characters are brought closer together
+by kerning; but it might be positive.
+
+There are eight kinds of ligature steps, having |op_byte| codes $4a+2b+c$ where
+$0\le a\le b+c$ and $0\le b,c\le1$. The character whose code is
+|remainder| is inserted between the current character and |next_char|;
+then the current character is deleted if $b=0$, and |next_char| is
+deleted if $c=0$; then we pass over $a$~characters to reach the next
+current character (which may have a ligature/kerning program of its own).
+
+If the very first instruction of the |lig_kern| array has |skip_byte=255|,
+the |next_char| byte is the so-called right boundary character of this font;
+the value of |next_char| need not lie between |bc| and~|ec|.
+If the very last instruction of the |lig_kern| array has |skip_byte=255|,
+there is a special ligature/kerning program for a left boundary character,
+beginning at location |256*op_byte+remainder|.
+The interpretation is that \TeX\ puts implicit boundary characters
+before and after each consecutive string of characters from the same font.
+These implicit characters do not appear in the output, but they can affect
+ligatures and kerning.
+
+If the very first instruction of a character's |lig_kern| program has
+|skip_byte>128|, the program actually begins in location
+|256*op_byte+remainder|. This feature allows access to large |lig_kern|
+arrays, because the first instruction must otherwise
+appear in a location |<=255|.
+
+Any instruction with |skip_byte>128| in the |lig_kern| array must satisfy
+the condition
+$$\hbox{|256*op_byte+remainder<nl|.}$$
+If such an instruction is encountered during
+normal program execution, it denotes an unconditional halt; no ligature
+command is performed.
+
+@d stop_flag (128)
+ /* value indicating `\.{STOP}' in a lig/kern program */
+@d kern_flag (128) /* op code for a kern step */
+@d skip_byte(A) mp->lig_kern[(A)].b0
+@d next_char(A) mp->lig_kern[(A)].b1
+@d op_byte(A) mp->lig_kern[(A)].b2
+@d rem_byte(A) mp->lig_kern[(A)].b3
+
+@ Extensible characters are specified by an |extensible_recipe|, which
+consists of four bytes called |top|, |mid|, |bot|, and |rep| (in this
+order). These bytes are the character codes of individual pieces used to
+build up a large symbol. If |top|, |mid|, or |bot| are zero, they are not
+present in the built-up result. For example, an extensible vertical line is
+like an extensible bracket, except that the top and bottom pieces are missing.
+
+Let $T$, $M$, $B$, and $R$ denote the respective pieces, or an empty box
+if the piece isn't present. Then the extensible characters have the form
+$TR^kMR^kB$ from top to bottom, for some |k>=0|, unless $M$ is absent;
+in the latter case we can have $TR^kB$ for both even and odd values of~|k|.
+The width of the extensible character is the width of $R$; and the
+height-plus-depth is the sum of the individual height-plus-depths of the
+components used, since the pieces are butted together in a vertical list.
+
+@d ext_top(A) mp->exten[(A)].b0 /* |top| piece in a recipe */
+@d ext_mid(A) mp->exten[(A)].b1 /* |mid| piece in a recipe */
+@d ext_bot(A) mp->exten[(A)].b2 /* |bot| piece in a recipe */
+@d ext_rep(A) mp->exten[(A)].b3 /* |rep| piece in a recipe */
+
+@ The final portion of a \.{TFM} file is the |param| array, which is another
+sequence of |fix_word| values.
+
+\yskip\hang|param[1]=slant| is the amount of italic slant, which is used
+to help position accents. For example, |slant=.25| means that when you go
+up one unit, you also go .25 units to the right. The |slant| is a pure
+number; it is the only |fix_word| other than the design size itself that is
+not scaled by the design size.
+@^design size@>
+
+\hang|param[2]=space| is the normal spacing between words in text.
+Note that character 040 in the font need not have anything to do with
+blank spaces.
+
+\hang|param[3]=space_stretch| is the amount of glue stretching between words.
+
+\hang|param[4]=space_shrink| is the amount of glue shrinking between words.
+
+\hang|param[5]=x_height| is the size of one ex in the font; it is also
+the height of letters for which accents don't have to be raised or lowered.
+
+\hang|param[6]=quad| is the size of one em in the font.
+
+\hang|param[7]=extra_space| is the amount added to |param[2]| at the
+ends of sentences.
+
+\yskip\noindent
+If fewer than seven parameters are present, \TeX\ sets the missing parameters
+to zero.
+
+@d slant_code 1
+@d space_code 2
+@d space_stretch_code 3
+@d space_shrink_code 4
+@d x_height_code 5
+@d quad_code 6
+@d extra_space_code 7
+
+@ So that is what \.{TFM} files hold. One of \MP's duties is to output such
+information, and it does this all at once at the end of a job.
+In order to prepare for such frenetic activity, it squirrels away the
+necessary facts in various arrays as information becomes available.
+
+Character dimensions (\&{charwd}, \&{charht}, \&{chardp}, and \&{charic})
+are stored respectively in |tfm_width|, |tfm_height|, |tfm_depth|, and
+|tfm_ital_corr|. Other information about a character (e.g., about
+its ligatures or successors) is accessible via the |char_tag| and
+|char_remainder| arrays. Other information about the font as a whole
+is kept in additional arrays called |header_byte|, |lig_kern|,
+|kern|, |exten|, and |param|.
+
+@d max_tfm_int 32510
+@d undefined_label max_tfm_int /* an undefined local label */
+
+@<Glob...@>=
+#define TFM_ITEMS 257
+eight_bits bc;
+eight_bits ec; /* smallest and largest character codes shipped out */
+scaled tfm_width[TFM_ITEMS]; /* \&{charwd} values */
+scaled tfm_height[TFM_ITEMS]; /* \&{charht} values */
+scaled tfm_depth[TFM_ITEMS]; /* \&{chardp} values */
+scaled tfm_ital_corr[TFM_ITEMS]; /* \&{charic} values */
+boolean char_exists[TFM_ITEMS]; /* has this code been shipped out? */
+int char_tag[TFM_ITEMS]; /* |remainder| category */
+int char_remainder[TFM_ITEMS]; /* the |remainder| byte */
+char *header_byte; /* bytes of the \.{TFM} header */
+int header_last; /* last initialized \.{TFM} header byte */
+int header_size; /* size of the \.{TFM} header */
+four_quarters *lig_kern; /* the ligature/kern table */
+short nl; /* the number of ligature/kern steps so far */
+scaled *kern; /* distinct kerning amounts */
+short nk; /* the number of distinct kerns so far */
+four_quarters exten[TFM_ITEMS]; /* extensible character recipes */
+short ne; /* the number of extensible characters so far */
+scaled *param; /* \&{fontinfo} parameters */
+short np; /* the largest \&{fontinfo} parameter specified so far */
+short nw;short nh;short nd;short ni; /* sizes of \.{TFM} subtables */
+short skip_table[TFM_ITEMS]; /* local label status */
+boolean lk_started; /* has there been a lig/kern step in this command yet? */
+integer bchar; /* right boundary character */
+short bch_label; /* left boundary starting location */
+short ll;short lll; /* registers used for lig/kern processing */
+short label_loc[257]; /* lig/kern starting addresses */
+eight_bits label_char[257]; /* characters for |label_loc| */
+short label_ptr; /* highest position occupied in |label_loc| */
+
+@ @<Allocate or initialize ...@>=
+mp->header_last=7;
+mp->header_size = 128; /* just for init */
+mp->header_byte = xmalloc(mp->header_size, sizeof(char));
+
+@ @<Dealloc variables@>=
+xfree(mp->header_byte);
+xfree(mp->lig_kern);
+xfree(mp->kern);
+xfree(mp->param);
+
+@ @<Set init...@>=
+for (k=0;k<= 255;k++ ) {
+ mp->tfm_width[k]=0; mp->tfm_height[k]=0; mp->tfm_depth[k]=0; mp->tfm_ital_corr[k]=0;
+ mp->char_exists[k]=false; mp->char_tag[k]=no_tag; mp->char_remainder[k]=0;
+ mp->skip_table[k]=undefined_label;
+}
+memset(mp->header_byte,0,(size_t)mp->header_size);
+mp->bc=255; mp->ec=0; mp->nl=0; mp->nk=0; mp->ne=0; mp->np=0;
+mp->internal[mp_boundary_char]=-unity;
+mp->bch_label=undefined_label;
+mp->label_loc[0]=-1; mp->label_ptr=0;
+
+@ @<Declarations@>=
+static scaled mp_tfm_check (MP mp,quarterword m) ;
+
+@ @c
+static scaled mp_tfm_check (MP mp,quarterword m) {
+ if ( abs(mp->internal[m])>=fraction_half ) {
+ print_err("Enormous "); mp_print(mp, mp->int_name[m]);
+@.Enormous charwd...@>
+@.Enormous chardp...@>
+@.Enormous charht...@>
+@.Enormous charic...@>
+@.Enormous designsize...@>
+ mp_print(mp, " has been reduced");
+ help1("Font metric dimensions must be less than 2048pt.");
+ mp_put_get_error(mp);
+ if ( mp->internal[m]>0 ) return (fraction_half-1);
+ else return (1-fraction_half);
+ } else {
+ return mp->internal[m];
+ }
+}
+
+@ @<Store the width information for character code~|c|@>=
+if ( c<mp->bc ) mp->bc=(eight_bits)c;
+if ( c>mp->ec ) mp->ec=(eight_bits)c;
+mp->char_exists[c]=true;
+mp->tfm_width[c]=mp_tfm_check(mp,mp_char_wd);
+mp->tfm_height[c]=mp_tfm_check(mp, mp_char_ht);
+mp->tfm_depth[c]=mp_tfm_check(mp, mp_char_dp);
+mp->tfm_ital_corr[c]=mp_tfm_check(mp, mp_char_ic)
+
+@ Now let's consider \MP's special \.{TFM}-oriented commands.
+
+@<Cases of |do_statement|...@>=
+case tfm_command: mp_do_tfm_command(mp); break;
+
+@ @d char_list_code 0
+@d lig_table_code 1
+@d extensible_code 2
+@d header_byte_code 3
+@d font_dimen_code 4
+
+@<Put each...@>=
+mp_primitive(mp, "charlist",tfm_command,char_list_code);
+@:char_list_}{\&{charlist} primitive@>
+mp_primitive(mp, "ligtable",tfm_command,lig_table_code);
+@:lig_table_}{\&{ligtable} primitive@>
+mp_primitive(mp, "extensible",tfm_command,extensible_code);
+@:extensible_}{\&{extensible} primitive@>
+mp_primitive(mp, "headerbyte",tfm_command,header_byte_code);
+@:header_byte_}{\&{headerbyte} primitive@>
+mp_primitive(mp, "fontdimen",tfm_command,font_dimen_code);
+@:font_dimen_}{\&{fontdimen} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case tfm_command:
+ switch (m) {
+ case char_list_code:mp_print(mp, "charlist"); break;
+ case lig_table_code:mp_print(mp, "ligtable"); break;
+ case extensible_code:mp_print(mp, "extensible"); break;
+ case header_byte_code:mp_print(mp, "headerbyte"); break;
+ default: mp_print(mp, "fontdimen"); break;
+ }
+ break;
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static eight_bits mp_get_code (MP mp) ;
+
+@ @c eight_bits mp_get_code (MP mp) { /* scans a character code value */
+ integer c; /* the code value found */
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type==mp_known ) {
+ c=mp_round_unscaled(mp, mp->cur_exp);
+ if ( c>=0 ) if ( c<256 ) return (eight_bits)c;
+ } else if ( mp->cur_type==mp_string_type ) {
+ if ( length(mp->cur_exp)==1 ) {
+ c=mp->str_pool[mp->str_start[mp->cur_exp]];
+ return (eight_bits)c;
+ }
+ }
+ exp_err("Invalid code has been replaced by 0");
+@.Invalid code...@>
+ help2("I was looking for a number between 0 and 255, or for a",
+ "string of length 1. Didn't find it; will use 0 instead.");
+ mp_put_get_flush_error(mp, 0); c=0;
+ return (eight_bits)c;
+}
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_set_tag (MP mp,halfword c, quarterword t, halfword r) ;
+
+@ @c void mp_set_tag (MP mp,halfword c, quarterword t, halfword r) {
+ if ( mp->char_tag[c]==no_tag ) {
+ mp->char_tag[c]=t; mp->char_remainder[c]=r;
+ if ( t==lig_tag ){
+ incr(mp->label_ptr); mp->label_loc[mp->label_ptr]=r;
+ mp->label_char[mp->label_ptr]=(eight_bits)c;
+ }
+ } else {
+ @<Complain about a character tag conflict@>;
+ }
+}
+
+@ @<Complain about a character tag conflict@>=
+{
+ print_err("Character ");
+ if ( (c>' ')&&(c<127) ) mp_print_char(mp,xord(c));
+ else if ( c==256 ) mp_print(mp, "||");
+ else { mp_print(mp, "code "); mp_print_int(mp, c); };
+ mp_print(mp, " is already ");
+@.Character c is already...@>
+ switch (mp->char_tag[c]) {
+ case lig_tag: mp_print(mp, "in a ligtable"); break;
+ case list_tag: mp_print(mp, "in a charlist"); break;
+ case ext_tag: mp_print(mp, "extensible"); break;
+ } /* there are no other cases */
+ help2("It's not legal to label a character more than once.",
+ "So I'll not change anything just now.");
+ mp_put_get_error(mp);
+}
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_do_tfm_command (MP mp) ;
+
+@ @c void mp_do_tfm_command (MP mp) {
+ int c,cc; /* character codes */
+ int k; /* index into the |kern| array */
+ int j; /* index into |header_byte| or |param| */
+ switch (mp->cur_mod) {
+ case char_list_code:
+ c=mp_get_code(mp);
+ /* we will store a list of character successors */
+ while ( mp->cur_cmd==colon ) {
+ cc=mp_get_code(mp); mp_set_tag(mp, c,list_tag,cc); c=cc;
+ };
+ break;
+ case lig_table_code:
+ if (mp->lig_kern==NULL)
+ mp->lig_kern = xmalloc((max_tfm_int+1),sizeof(four_quarters));
+ if (mp->kern==NULL)
+ mp->kern = xmalloc((max_tfm_int+1),sizeof(scaled));
+ @<Store a list of ligature/kern steps@>;
+ break;
+ case extensible_code:
+ @<Define an extensible recipe@>;
+ break;
+ case header_byte_code:
+ case font_dimen_code:
+ c=mp->cur_mod; mp_get_x_next(mp);
+ mp_scan_expression(mp);
+ if ( (mp->cur_type!=mp_known)||(mp->cur_exp<half_unit) ) {
+ exp_err("Improper location");
+@.Improper location@>
+ help2("I was looking for a known, positive number.",
+ "For safety's sake I'll ignore the present command.");
+ mp_put_get_error(mp);
+ } else {
+ j=mp_round_unscaled(mp, mp->cur_exp);
+ if ( mp->cur_cmd!=colon ) {
+ mp_missing_err(mp, ":");
+@.Missing `:'@>
+ help1("A colon should follow a headerbyte or fontinfo location.");
+ mp_back_error(mp);
+ }
+ if ( c==header_byte_code ) {
+ @<Store a list of header bytes@>;
+ } else {
+ if (mp->param==NULL)
+ mp->param = xmalloc((max_tfm_int+1),sizeof(scaled));
+ @<Store a list of font dimensions@>;
+ }
+ }
+ break;
+ } /* there are no other cases */
+}
+
+@ @<Store a list of ligature/kern steps@>=
+{
+ mp->lk_started=false;
+CONTINUE:
+ mp_get_x_next(mp);
+ if ((mp->cur_cmd==skip_to)&& mp->lk_started )
+ @<Process a |skip_to| command and |goto done|@>;
+ if ( mp->cur_cmd==bchar_label ) { c=256; mp->cur_cmd=colon; }
+ else { mp_back_input(mp); c=mp_get_code(mp); };
+ if ((mp->cur_cmd==colon)||(mp->cur_cmd==double_colon)) {
+ @<Record a label in a lig/kern subprogram and |goto continue|@>;
+ }
+ if ( mp->cur_cmd==lig_kern_token ) {
+ @<Compile a ligature/kern command@>;
+ } else {
+ print_err("Illegal ligtable step");
+@.Illegal ligtable step@>
+ help1("I was looking for `=:' or `kern' here.");
+ mp_back_error(mp); next_char(mp->nl)=qi(0);
+ op_byte(mp->nl)=qi(0); rem_byte(mp->nl)=qi(0);
+ skip_byte(mp->nl)=stop_flag+1; /* this specifies an unconditional stop */
+ }
+ if ( mp->nl==max_tfm_int) mp_fatal_error(mp, "ligtable too large");
+ incr(mp->nl);
+ if ( mp->cur_cmd==comma ) goto CONTINUE;
+ if ( skip_byte(mp->nl-1)<stop_flag ) skip_byte(mp->nl-1)=stop_flag;
+}
+DONE:
+
+@ @<Put each...@>=
+mp_primitive(mp, "=:",lig_kern_token,0);
+@:=:_}{\.{=:} primitive@>
+mp_primitive(mp, "=:|",lig_kern_token,1);
+@:=:/_}{\.{=:\char'174} primitive@>
+mp_primitive(mp, "=:|>",lig_kern_token,5);
+@:=:/>_}{\.{=:\char'174>} primitive@>
+mp_primitive(mp, "|=:",lig_kern_token,2);
+@:=:/_}{\.{\char'174=:} primitive@>
+mp_primitive(mp, "|=:>",lig_kern_token,6);
+@:=:/>_}{\.{\char'174=:>} primitive@>
+mp_primitive(mp, "|=:|",lig_kern_token,3);
+@:=:/_}{\.{\char'174=:\char'174} primitive@>
+mp_primitive(mp, "|=:|>",lig_kern_token,7);
+@:=:/>_}{\.{\char'174=:\char'174>} primitive@>
+mp_primitive(mp, "|=:|>>",lig_kern_token,11);
+@:=:/>_}{\.{\char'174=:\char'174>>} primitive@>
+mp_primitive(mp, "kern",lig_kern_token,128);
+@:kern_}{\&{kern} primitive@>
+
+@ @<Cases of |print_cmd...@>=
+case lig_kern_token:
+ switch (m) {
+ case 0:mp_print(mp, "=:"); break;
+ case 1:mp_print(mp, "=:|"); break;
+ case 2:mp_print(mp, "|=:"); break;
+ case 3:mp_print(mp, "|=:|"); break;
+ case 5:mp_print(mp, "=:|>"); break;
+ case 6:mp_print(mp, "|=:>"); break;
+ case 7:mp_print(mp, "|=:|>"); break;
+ case 11:mp_print(mp, "|=:|>>"); break;
+ default: mp_print(mp, "kern"); break;
+ }
+ break;
+
+@ Local labels are implemented by maintaining the |skip_table| array,
+where |skip_table[c]| is either |undefined_label| or the address of the
+most recent lig/kern instruction that skips to local label~|c|. In the
+latter case, the |skip_byte| in that instruction will (temporarily)
+be zero if there were no prior skips to this label, or it will be the
+distance to the prior skip.
+
+We may need to cancel skips that span more than 127 lig/kern steps.
+
+@d cancel_skips(A) mp->ll=(A);
+ do {
+ mp->lll=qo(skip_byte(mp->ll));
+ skip_byte(mp->ll)=stop_flag; mp->ll=mp->ll-mp->lll;
+ } while (mp->lll!=0)
+@d skip_error(A) { print_err("Too far to skip");
+@.Too far to skip@>
+ help1("At most 127 lig/kern steps can separate skipto1 from 1::.");
+ mp_error(mp); cancel_skips((A));
+ }
+
+@<Process a |skip_to| command and |goto done|@>=
+{
+ c=mp_get_code(mp);
+ if ( mp->nl-mp->skip_table[c]>128 ) {
+ skip_error(mp->skip_table[c]); mp->skip_table[c]=undefined_label;
+ }
+ if ( mp->skip_table[c]==undefined_label ) skip_byte(mp->nl-1)=qi(0);
+ else skip_byte(mp->nl-1)=qi(mp->nl-mp->skip_table[c]-1);
+ mp->skip_table[c]=mp->nl-1; goto DONE;
+}
+
+@ @<Record a label in a lig/kern subprogram and |goto continue|@>=
+{
+ if ( mp->cur_cmd==colon ) {
+ if ( c==256 ) mp->bch_label=mp->nl;
+ else mp_set_tag(mp, c,lig_tag,mp->nl);
+ } else if ( mp->skip_table[c]<undefined_label ) {
+ mp->ll=mp->skip_table[c]; mp->skip_table[c]=undefined_label;
+ do {
+ mp->lll=qo(skip_byte(mp->ll));
+ if ( mp->nl-mp->ll>128 ) {
+ skip_error(mp->ll); goto CONTINUE;
+ }
+ skip_byte(mp->ll)=qi(mp->nl-mp->ll-1); mp->ll=mp->ll-mp->lll;
+ } while (mp->lll!=0);
+ }
+ goto CONTINUE;
+}
+
+@ @<Compile a ligature/kern...@>=
+{
+ next_char(mp->nl)=qi(c); skip_byte(mp->nl)=qi(0);
+ if ( mp->cur_mod<128 ) { /* ligature op */
+ op_byte(mp->nl)=qi(mp->cur_mod); rem_byte(mp->nl)=qi(mp_get_code(mp));
+ } else {
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_known ) {
+ exp_err("Improper kern");
+@.Improper kern@>
+ help2("The amount of kern should be a known numeric value.",
+ "I'm zeroing this one. Proceed, with fingers crossed.");
+ mp_put_get_flush_error(mp, 0);
+ }
+ mp->kern[mp->nk]=mp->cur_exp;
+ k=0;
+ while ( mp->kern[k]!=mp->cur_exp ) incr(k);
+ if ( k==mp->nk ) {
+ if ( mp->nk==max_tfm_int ) mp_fatal_error(mp, "too many TFM kerns");
+ incr(mp->nk);
+ }
+ op_byte(mp->nl)=kern_flag+(k / 256);
+ rem_byte(mp->nl)=qi((k % 256));
+ }
+ mp->lk_started=true;
+}
+
+@ @d missing_extensible_punctuation(A)
+ { mp_missing_err(mp, (A));
+@.Missing `\char`\#'@>
+ help1("I'm processing `extensible c: t,m,b,r'."); mp_back_error(mp);
+ }
+
+@<Define an extensible recipe@>=
+{
+ if ( mp->ne==256 ) mp_fatal_error(mp, "too many extensible recipies");
+ c=mp_get_code(mp); mp_set_tag(mp, c,ext_tag,mp->ne);
+ if ( mp->cur_cmd!=colon ) missing_extensible_punctuation(":");
+ ext_top(mp->ne)=qi(mp_get_code(mp));
+ if ( mp->cur_cmd!=comma ) missing_extensible_punctuation(",");
+ ext_mid(mp->ne)=qi(mp_get_code(mp));
+ if ( mp->cur_cmd!=comma ) missing_extensible_punctuation(",");
+ ext_bot(mp->ne)=qi(mp_get_code(mp));
+ if ( mp->cur_cmd!=comma ) missing_extensible_punctuation(",");
+ ext_rep(mp->ne)=qi(mp_get_code(mp));
+ incr(mp->ne);
+}
+
+@ The header could contain ASCII zeroes, so can't use |strdup|.
+
+@<Store a list of header bytes@>=
+do {
+ if ( j>=mp->header_size ) {
+ size_t l = (size_t)(mp->header_size + (mp->header_size/4));
+ char *t = xmalloc(l,1);
+ memset(t,0,l);
+ memcpy(t,mp->header_byte,(size_t)mp->header_size);
+ xfree (mp->header_byte);
+ mp->header_byte = t;
+ mp->header_size = (int)l;
+ }
+ mp->header_byte[j]=(char)mp_get_code(mp);
+ incr(j); incr(mp->header_last);
+} while (mp->cur_cmd==comma)
+
+@ @<Store a list of font dimensions@>=
+do {
+ if ( j>max_tfm_int ) mp_fatal_error(mp, "too many fontdimens");
+ while ( j>mp->np ) { incr(mp->np); mp->param[mp->np]=0; };
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_known ){
+ exp_err("Improper font parameter");
+@.Improper font parameter@>
+ help1("I'm zeroing this one. Proceed, with fingers crossed.");
+ mp_put_get_flush_error(mp, 0);
+ }
+ mp->param[j]=mp->cur_exp; incr(j);
+} while (mp->cur_cmd==comma)
+
+@ OK: We've stored all the data that is needed for the \.{TFM} file.
+All that remains is to output it in the correct format.
+
+An interesting problem needs to be solved in this connection, because
+the \.{TFM} format allows at most 256~widths, 16~heights, 16~depths,
+and 64~italic corrections. If the data has more distinct values than
+this, we want to meet the necessary restrictions by perturbing the
+given values as little as possible.
+
+\MP\ solves this problem in two steps. First the values of a given
+kind (widths, heights, depths, or italic corrections) are sorted;
+then the list of sorted values is perturbed, if necessary.
+
+The sorting operation is facilitated by having a special node of
+essentially infinite |value| at the end of the current list.
+
+@<Initialize table entries...@>=
+value(inf_val)=fraction_four;
+
+@ Straight linear insertion is good enough for sorting, since the lists
+are usually not terribly long. As we work on the data, the current list
+will start at |mp_link(temp_head)| and end at |inf_val|; the nodes in this
+list will be in increasing order of their |value| fields.
+
+Given such a list, the |sort_in| function takes a value and returns a pointer
+to where that value can be found in the list. The value is inserted in
+the proper place, if necessary.
+
+At the time we need to do these operations, most of \MP's work has been
+completed, so we will have plenty of memory to play with. The value nodes
+that are allocated for sorting will never be returned to free storage.
+
+@d clear_the_list mp_link(temp_head)=inf_val
+
+@c
+static pointer mp_sort_in (MP mp,scaled v) {
+ pointer p,q,r; /* list manipulation registers */
+ p=temp_head;
+ while (1) {
+ q=mp_link(p);
+ if ( v<=value(q) ) break;
+ p=q;
+ }
+ if ( v<value(q) ) {
+ r=mp_get_node(mp, value_node_size); value(r)=v; mp_link(r)=q; mp_link(p)=r;
+ }
+ return mp_link(p);
+}
+
+@ Now we come to the interesting part, where we reduce the list if necessary
+until it has the required size. The |min_cover| routine is basic to this
+process; it computes the minimum number~|m| such that the values of the
+current sorted list can be covered by |m|~intervals of width~|d|. It
+also sets the global value |perturbation| to the smallest value $d'>d$
+such that the covering found by this algorithm would be different.
+
+In particular, |min_cover(0)| returns the number of distinct values in the
+current list and sets |perturbation| to the minimum distance between
+adjacent values.
+
+@c
+static integer mp_min_cover (MP mp,scaled d) {
+ pointer p; /* runs through the current list */
+ scaled l; /* the least element covered by the current interval */
+ integer m; /* lower bound on the size of the minimum cover */
+ m=0; p=mp_link(temp_head); mp->perturbation=el_gordo;
+ while ( p!=inf_val ){
+ incr(m); l=value(p);
+ do { p=mp_link(p); } while (value(p)<=l+d);
+ if ( value(p)-l<mp->perturbation )
+ mp->perturbation=value(p)-l;
+ }
+ return m;
+}
+
+@ @<Glob...@>=
+scaled perturbation; /* quantity related to \.{TFM} rounding */
+integer excess; /* the list is this much too long */
+
+@ The smallest |d| such that a given list can be covered with |m| intervals
+is determined by the |threshold| routine, which is sort of an inverse
+to |min_cover|. The idea is to increase the interval size rapidly until
+finding the range, then to go sequentially until the exact borderline has
+been discovered.
+
+@c
+static scaled mp_threshold (MP mp,integer m) {
+ scaled d; /* lower bound on the smallest interval size */
+ mp->excess=mp_min_cover(mp, 0)-m;
+ if ( mp->excess<=0 ) {
+ return 0;
+ } else {
+ do {
+ d=mp->perturbation;
+ } while (mp_min_cover(mp, d+d)>m);
+ while ( mp_min_cover(mp, d)>m )
+ d=mp->perturbation;
+ return d;
+ }
+}
+
+@ The |skimp| procedure reduces the current list to at most |m| entries,
+by changing values if necessary. It also sets |mp_info(p):=k| if |value(p)|
+is the |k|th distinct value on the resulting list, and it sets
+|perturbation| to the maximum amount by which a |value| field has
+been changed. The size of the resulting list is returned as the
+value of |skimp|.
+
+@c
+static integer mp_skimp (MP mp,integer m) {
+ scaled d; /* the size of intervals being coalesced */
+ pointer p,q,r; /* list manipulation registers */
+ scaled l; /* the least value in the current interval */
+ scaled v; /* a compromise value */
+ d=mp_threshold(mp, m); mp->perturbation=0;
+ q=temp_head; m=0; p=mp_link(temp_head);
+ while ( p!=inf_val ) {
+ incr(m); l=value(p); mp_info(p)=m;
+ if ( value(mp_link(p))<=l+d ) {
+ @<Replace an interval of values by its midpoint@>;
+ }
+ q=p; p=mp_link(p);
+ }
+ return m;
+}
+
+@ @<Replace an interval...@>=
+{
+ do {
+ p=mp_link(p); mp_info(p)=m;
+ decr(mp->excess); if ( mp->excess==0 ) d=0;
+ } while (value(mp_link(p))<=l+d);
+ v=l+halfp(value(p)-l);
+ if ( value(p)-v>mp->perturbation )
+ mp->perturbation=value(p)-v;
+ r=q;
+ do {
+ r=mp_link(r); value(r)=v;
+ } while (r!=p);
+ mp_link(q)=p; /* remove duplicate values from the current list */
+}
+
+@ A warning message is issued whenever something is perturbed by
+more than 1/16\thinspace pt.
+
+@c
+static void mp_tfm_warning (MP mp,quarterword m) {
+ mp_print_nl(mp, "(some ");
+ mp_print(mp, mp->int_name[m]);
+@.some charwds...@>
+@.some chardps...@>
+@.some charhts...@>
+@.some charics...@>
+ mp_print(mp, " values had to be adjusted by as much as ");
+ mp_print_scaled(mp, mp->perturbation); mp_print(mp, "pt)");
+}
+
+@ Here's an example of how we use these routines.
+The width data needs to be perturbed only if there are 256 distinct
+widths, but \MP\ must check for this case even though it is
+highly unusual.
+
+An integer variable |k| will be defined when we use this code.
+The |dimen_head| array will contain pointers to the sorted
+lists of dimensions.
+
+@<Massage the \.{TFM} widths@>=
+clear_the_list;
+for (k=mp->bc;k<=mp->ec;k++) {
+ if ( mp->char_exists[k] )
+ mp->tfm_width[k]=mp_sort_in(mp, mp->tfm_width[k]);
+}
+mp->nw=mp_skimp(mp, 255)+1; mp->dimen_head[1]=mp_link(temp_head);
+if ( mp->perturbation>=010000 ) mp_tfm_warning(mp, mp_char_wd)
+
+@ @<Glob...@>=
+pointer dimen_head[5]; /* lists of \.{TFM} dimensions */
+
+@ Heights, depths, and italic corrections are different from widths
+not only because their list length is more severely restricted, but
+also because zero values do not need to be put into the lists.
+
+@<Massage the \.{TFM} heights, depths, and italic corrections@>=
+clear_the_list;
+for (k=mp->bc;k<=mp->ec;k++) {
+ if ( mp->char_exists[k] ) {
+ if ( mp->tfm_height[k]==0 ) mp->tfm_height[k]=zero_val;
+ else mp->tfm_height[k]=mp_sort_in(mp, mp->tfm_height[k]);
+ }
+}
+mp->nh=mp_skimp(mp, 15)+1; mp->dimen_head[2]=mp_link(temp_head);
+if ( mp->perturbation>=010000 ) mp_tfm_warning(mp, mp_char_ht);
+clear_the_list;
+for (k=mp->bc;k<=mp->ec;k++) {
+ if ( mp->char_exists[k] ) {
+ if ( mp->tfm_depth[k]==0 ) mp->tfm_depth[k]=zero_val;
+ else mp->tfm_depth[k]=mp_sort_in(mp, mp->tfm_depth[k]);
+ }
+}
+mp->nd=mp_skimp(mp, 15)+1; mp->dimen_head[3]=mp_link(temp_head);
+if ( mp->perturbation>=010000 ) mp_tfm_warning(mp, mp_char_dp);
+clear_the_list;
+for (k=mp->bc;k<=mp->ec;k++) {
+ if ( mp->char_exists[k] ) {
+ if ( mp->tfm_ital_corr[k]==0 ) mp->tfm_ital_corr[k]=zero_val;
+ else mp->tfm_ital_corr[k]=mp_sort_in(mp, mp->tfm_ital_corr[k]);
+ }
+}
+mp->ni=mp_skimp(mp, 63)+1; mp->dimen_head[4]=mp_link(temp_head);
+if ( mp->perturbation>=010000 ) mp_tfm_warning(mp, mp_char_ic)
+
+@ @<Initialize table entries...@>=
+value(zero_val)=0; mp_info(zero_val)=0;
+
+@ Bytes 5--8 of the header are set to the design size, unless the user has
+some crazy reason for specifying them differently.
+@^design size@>
+
+Error messages are not allowed at the time this procedure is called,
+so a warning is printed instead.
+
+The value of |max_tfm_dimen| is calculated so that
+$$\hbox{|make_scaled(16*max_tfm_dimen,internal[mp_design_size])|}
+ < \\{three\_bytes}.$$
+
+@d three_bytes 0100000000 /* $2^{24}$ */
+
+@c
+static void mp_fix_design_size (MP mp) {
+ scaled d; /* the design size */
+ d=mp->internal[mp_design_size];
+ if ( (d<unity)||(d>=fraction_half) ) {
+ if ( d!=0 )
+ mp_print_nl(mp, "(illegal design size has been changed to 128pt)");
+@.illegal design size...@>
+ d=040000000; mp->internal[mp_design_size]=d;
+ }
+ if ( mp->header_byte[4]==0 && mp->header_byte[5]==0 &&
+ mp->header_byte[6]==0 && mp->header_byte[7]==0 ) {
+ mp->header_byte[4]=d / 04000000;
+ mp->header_byte[5]=(d / 4096) % 256;
+ mp->header_byte[6]=(d / 16) % 256;
+ mp->header_byte[7]=(d % 16)*16;
+ }
+ mp->max_tfm_dimen=16*mp->internal[mp_design_size]-1-mp->internal[mp_design_size] / 010000000;
+ if ( mp->max_tfm_dimen>=fraction_half ) mp->max_tfm_dimen=fraction_half-1;
+}
+
+@ The |dimen_out| procedure computes a |fix_word| relative to the
+design size. If the data was out of range, it is corrected and the
+global variable |tfm_changed| is increased by~one.
+
+@c
+static integer mp_dimen_out (MP mp,scaled x) {
+ if ( abs(x)>mp->max_tfm_dimen ) {
+ incr(mp->tfm_changed);
+ if ( x>0 ) x=mp->max_tfm_dimen; else x=-mp->max_tfm_dimen;
+ }
+ x=mp_make_scaled(mp, x*16,mp->internal[mp_design_size]);
+ return x;
+}
+
+@ @<Glob...@>=
+scaled max_tfm_dimen; /* bound on widths, heights, kerns, etc. */
+integer tfm_changed; /* the number of data entries that were out of bounds */
+
+@ If the user has not specified any of the first four header bytes,
+the |fix_check_sum| procedure replaces them by a ``check sum'' computed
+from the |tfm_width| data relative to the design size.
+@^check sum@>
+
+@c
+static void mp_fix_check_sum (MP mp) {
+ eight_bits k; /* runs through character codes */
+ eight_bits B1,B2,B3,B4; /* bytes of the check sum */
+ integer x; /* hash value used in check sum computation */
+ if ( mp->header_byte[0]==0 && mp->header_byte[1]==0 &&
+ mp->header_byte[2]==0 && mp->header_byte[3]==0 ) {
+ @<Compute a check sum in |(b1,b2,b3,b4)|@>;
+ mp->header_byte[0]=(char)B1; mp->header_byte[1]=(char)B2;
+ mp->header_byte[2]=(char)B3; mp->header_byte[3]=(char)B4;
+ return;
+ }
+}
+
+@ @<Compute a check sum in |(b1,b2,b3,b4)|@>=
+B1=mp->bc; B2=mp->ec; B3=mp->bc; B4=mp->ec; mp->tfm_changed=0;
+for (k=mp->bc;k<=mp->ec;k++) {
+ if ( mp->char_exists[k] ) {
+ x=mp_dimen_out(mp, value(mp->tfm_width[k]))+(k+4)*020000000; /* this is positive */
+ B1=(eight_bits)((B1+B1+x) % 255);
+ B2=(eight_bits)((B2+B2+x) % 253);
+ B3=(eight_bits)((B3+B3+x) % 251);
+ B4=(eight_bits)((B4+B4+x) % 247);
+ }
+ if (k==mp->ec) break;
+}
+
+@ Finally we're ready to actually write the \.{TFM} information.
+Here are some utility routines for this purpose.
+
+@d tfm_out(A) do { /* output one byte to |tfm_file| */
+ unsigned char s=(unsigned char)(A);
+ (mp->write_binary_file)(mp,mp->tfm_file,(void *)&s,1);
+ } while (0)
+
+@c
+static void mp_tfm_two (MP mp,integer x) { /* output two bytes to |tfm_file| */
+ tfm_out(x / 256); tfm_out(x % 256);
+}
+static void mp_tfm_four (MP mp,integer x) { /* output four bytes to |tfm_file| */
+ if ( x>=0 ) tfm_out(x / three_bytes);
+ else {
+ x=x+010000000000; /* use two's complement for negative values */
+ x=x+010000000000;
+ tfm_out((x / three_bytes) + 128);
+ };
+ x=x % three_bytes; tfm_out(x / unity);
+ x=x % unity; tfm_out(x / 0400);
+ tfm_out(x % 0400);
+}
+static void mp_tfm_qqqq (MP mp,four_quarters x) { /* output four quarterwords to |tfm_file| */
+ tfm_out(qo(x.b0)); tfm_out(qo(x.b1));
+ tfm_out(qo(x.b2)); tfm_out(qo(x.b3));
+}
+
+@ @<Finish the \.{TFM} file@>=
+if ( mp->job_name==NULL ) mp_open_log_file(mp);
+mp_pack_job_name(mp, ".tfm");
+while ( ! mp_b_open_out(mp, &mp->tfm_file, mp_filetype_metrics) )
+ mp_prompt_file_name(mp, "file name for font metrics",".tfm");
+mp->metric_file_name=xstrdup(mp->name_of_file);
+@<Output the subfile sizes and header bytes@>;
+@<Output the character information bytes, then
+ output the dimensions themselves@>;
+@<Output the ligature/kern program@>;
+@<Output the extensible character recipes and the font metric parameters@>;
+ if ( mp->internal[mp_tracing_stats]>0 )
+ @<Log the subfile sizes of the \.{TFM} file@>;
+mp_print_nl(mp, "Font metrics written on ");
+mp_print(mp, mp->metric_file_name); mp_print_char(mp, xord('.'));
+@.Font metrics written...@>
+(mp->close_file)(mp,mp->tfm_file)
+
+@ Integer variables |lh|, |k|, and |lk_offset| will be defined when we use
+this code.
+
+@<Output the subfile sizes and header bytes@>=
+k=mp->header_last;
+LH=(k+4) / 4; /* this is the number of header words */
+if ( mp->bc>mp->ec ) mp->bc=1; /* if there are no characters, |ec=0| and |bc=1| */
+@<Compute the ligature/kern program offset and implant the
+ left boundary label@>;
+mp_tfm_two(mp,6+LH+(mp->ec-mp->bc+1)+mp->nw+mp->nh+mp->nd+mp->ni+mp->nl
+ +lk_offset+mp->nk+mp->ne+mp->np);
+ /* this is the total number of file words that will be output */
+mp_tfm_two(mp, LH); mp_tfm_two(mp, mp->bc); mp_tfm_two(mp, mp->ec);
+mp_tfm_two(mp, mp->nw); mp_tfm_two(mp, mp->nh);
+mp_tfm_two(mp, mp->nd); mp_tfm_two(mp, mp->ni); mp_tfm_two(mp, mp->nl+lk_offset);
+mp_tfm_two(mp, mp->nk); mp_tfm_two(mp, mp->ne);
+mp_tfm_two(mp, mp->np);
+for (k=0;k< 4*LH;k++) {
+ tfm_out(mp->header_byte[k]);
+}
+
+@ @<Output the character information bytes...@>=
+for (k=mp->bc;k<=mp->ec;k++) {
+ if ( ! mp->char_exists[k] ) {
+ mp_tfm_four(mp, 0);
+ } else {
+ tfm_out(mp_info(mp->tfm_width[k])); /* the width index */
+ tfm_out((mp_info(mp->tfm_height[k]))*16+mp_info(mp->tfm_depth[k]));
+ tfm_out((mp_info(mp->tfm_ital_corr[k]))*4+mp->char_tag[k]);
+ tfm_out(mp->char_remainder[k]);
+ };
+}
+mp->tfm_changed=0;
+for (k=1;k<=4;k++) {
+ mp_tfm_four(mp, 0); p=mp->dimen_head[k];
+ while ( p!=inf_val ) {
+ mp_tfm_four(mp, mp_dimen_out(mp, value(p))); p=mp_link(p);
+ }
+}
+
+
+@ We need to output special instructions at the beginning of the
+|lig_kern| array in order to specify the right boundary character
+and/or to handle starting addresses that exceed 255. The |label_loc|
+and |label_char| arrays have been set up to record all the
+starting addresses; we have $-1=|label_loc|[0]<|label_loc|[1]\le\cdots
+\le|label_loc|[|label_ptr]|$.
+
+@<Compute the ligature/kern program offset...@>=
+mp->bchar=mp_round_unscaled(mp, mp->internal[mp_boundary_char]);
+if ((mp->bchar<0)||(mp->bchar>255)) {
+ mp->bchar=-1; mp->lk_started=false; lk_offset=0;
+} else {
+ mp->lk_started=true; lk_offset=1;
+}
+@<Find the minimum |lk_offset| and adjust all remainders@>;
+if ( mp->bch_label<undefined_label )
+ { skip_byte(mp->nl)=qi(255); next_char(mp->nl)=qi(0);
+ op_byte(mp->nl)=qi(((mp->bch_label+lk_offset)/ 256));
+ rem_byte(mp->nl)=qi(((mp->bch_label+lk_offset)% 256));
+ incr(mp->nl); /* possibly |nl=lig_table_size+1| */
+ }
+
+@ @<Find the minimum |lk_offset|...@>=
+k=mp->label_ptr; /* pointer to the largest unallocated label */
+if ( mp->label_loc[k]+lk_offset>255 ) {
+ lk_offset=0; mp->lk_started=false; /* location 0 can do double duty */
+ do {
+ mp->char_remainder[mp->label_char[k]]=lk_offset;
+ while ( mp->label_loc[k-1]==mp->label_loc[k] ) {
+ decr(k); mp->char_remainder[mp->label_char[k]]=lk_offset;
+ }
+ incr(lk_offset); decr(k);
+ } while (! (lk_offset+mp->label_loc[k]<256));
+ /* N.B.: |lk_offset=256| satisfies this when |k=0| */
+}
+if ( lk_offset>0 ) {
+ while ( k>0 ) {
+ mp->char_remainder[mp->label_char[k]]
+ =mp->char_remainder[mp->label_char[k]]+lk_offset;
+ decr(k);
+ }
+}
+
+@ @<Output the ligature/kern program@>=
+for (k=0;k<= 255;k++ ) {
+ if ( mp->skip_table[k]<undefined_label ) {
+ mp_print_nl(mp, "(local label "); mp_print_int(mp, k); mp_print(mp, ":: was missing)");
+@.local label l:: was missing@>
+ cancel_skips(mp->skip_table[k]);
+ }
+}
+if ( mp->lk_started ) { /* |lk_offset=1| for the special |bchar| */
+ tfm_out(255); tfm_out(mp->bchar); mp_tfm_two(mp, 0);
+} else {
+ for (k=1;k<=lk_offset;k++) {/* output the redirection specs */
+ mp->ll=mp->label_loc[mp->label_ptr];
+ if ( mp->bchar<0 ) { tfm_out(254); tfm_out(0); }
+ else { tfm_out(255); tfm_out(mp->bchar); };
+ mp_tfm_two(mp, mp->ll+lk_offset);
+ do {
+ decr(mp->label_ptr);
+ } while (! (mp->label_loc[mp->label_ptr]<mp->ll));
+ }
+}
+for (k=0;k<mp->nl;k++) mp_tfm_qqqq(mp, mp->lig_kern[k]);
+for (k=0;k<mp->nk;k++) mp_tfm_four(mp, mp_dimen_out(mp, mp->kern[k]))
+
+@ @<Output the extensible character recipes...@>=
+for (k=0;k<mp->ne;k++)
+ mp_tfm_qqqq(mp, mp->exten[k]);
+for (k=1;k<=mp->np;k++) {
+ if ( k==1 ) {
+ if ( abs(mp->param[1])<fraction_half ) {
+ mp_tfm_four(mp, mp->param[1]*16);
+ } else {
+ incr(mp->tfm_changed);
+ if ( mp->param[1]>0 ) mp_tfm_four(mp, el_gordo);
+ else mp_tfm_four(mp, -el_gordo);
+ }
+ } else {
+ mp_tfm_four(mp, mp_dimen_out(mp, mp->param[k]));
+ }
+}
+if ( mp->tfm_changed>0 ) {
+ if ( mp->tfm_changed==1 ) mp_print_nl(mp, "(a font metric dimension");
+@.a font metric dimension...@>
+ else {
+ mp_print_nl(mp, "("); mp_print_int(mp, mp->tfm_changed);
+@.font metric dimensions...@>
+ mp_print(mp, " font metric dimensions");
+ }
+ mp_print(mp, " had to be decreased)");
+}
+
+@ @<Log the subfile sizes of the \.{TFM} file@>=
+{
+ char s[200];
+ wlog_ln(" ");
+ if ( mp->bch_label<undefined_label ) decr(mp->nl);
+ mp_snprintf(s,128,"(You used %iw,%ih,%id,%ii,%il,%ik,%ie,%ip metric file positions)",
+ mp->nw, mp->nh, mp->nd, mp->ni, mp->nl, mp->nk, mp->ne,mp->np);
+ wlog_ln(s);
+}
+
+@* \[43] Reading font metric data.
+
+\MP\ isn't a typesetting program but it does need to find the bounding box
+of a sequence of typeset characters. Thus it needs to read \.{TFM} files as
+well as write them.
+
+@<Glob...@>=
+void * tfm_infile;
+
+@ All the width, height, and depth information is stored in an array called
+|font_info|. This array is allocated sequentially and each font is stored
+as a series of |char_info| words followed by the width, height, and depth
+tables. Since |font_name| entries are permanent, their |str_ref| values are
+set to |max_str_ref|.
+
+@<Types...@>=
+typedef unsigned int font_number; /* |0..font_max| */
+
+@ The |font_info| array is indexed via a group directory arrays.
+For example, the |char_info| data for character~|c| in font~|f| will be
+in |font_info[char_base[f]+c].qqqq|.
+
+@<Glob...@>=
+font_number font_max; /* maximum font number for included text fonts */
+size_t font_mem_size; /* number of words for \.{TFM} information for text fonts */
+memory_word *font_info; /* height, width, and depth data */
+char **font_enc_name; /* encoding names, if any */
+boolean *font_ps_name_fixed; /* are the postscript names fixed already? */
+size_t next_fmem; /* next unused entry in |font_info| */
+font_number last_fnum; /* last font number used so far */
+scaled *font_dsize; /* 16 times the ``design'' size in \ps\ points */
+char **font_name; /* name as specified in the \&{infont} command */
+char **font_ps_name; /* PostScript name for use when |internal[mp_prologues]>0| */
+font_number last_ps_fnum; /* last valid |font_ps_name| index */
+eight_bits *font_bc;
+eight_bits *font_ec; /* first and last character code */
+int *char_base; /* base address for |char_info| */
+int *width_base; /* index for zeroth character width */
+int *height_base; /* index for zeroth character height */
+int *depth_base; /* index for zeroth character depth */
+pointer *font_sizes;
+
+@ @<Allocate or initialize ...@>=
+mp->font_mem_size = 10000;
+mp->font_info = xmalloc ((mp->font_mem_size+1),sizeof(memory_word));
+memset (mp->font_info,0,sizeof(memory_word)*(mp->font_mem_size+1));
+mp->last_fnum = null_font;
+
+@ @<Dealloc variables@>=
+for (k=1;k<=(int)mp->last_fnum;k++) {
+ xfree(mp->font_enc_name[k]);
+ xfree(mp->font_name[k]);
+ xfree(mp->font_ps_name[k]);
+}
+xfree(mp->font_info);
+xfree(mp->font_enc_name);
+xfree(mp->font_ps_name_fixed);
+xfree(mp->font_dsize);
+xfree(mp->font_name);
+xfree(mp->font_ps_name);
+xfree(mp->font_bc);
+xfree(mp->font_ec);
+xfree(mp->char_base);
+xfree(mp->width_base);
+xfree(mp->height_base);
+xfree(mp->depth_base);
+xfree(mp->font_sizes);
+
+@
+@c
+void mp_reallocate_fonts (MP mp, font_number l) {
+ font_number f;
+ XREALLOC(mp->font_enc_name, l, char *);
+ XREALLOC(mp->font_ps_name_fixed, l, boolean);
+ XREALLOC(mp->font_dsize, l, scaled);
+ XREALLOC(mp->font_name, l, char *);
+ XREALLOC(mp->font_ps_name, l, char *);
+ XREALLOC(mp->font_bc, l, eight_bits);
+ XREALLOC(mp->font_ec, l, eight_bits);
+ XREALLOC(mp->char_base, l, int);
+ XREALLOC(mp->width_base, l, int);
+ XREALLOC(mp->height_base, l, int);
+ XREALLOC(mp->depth_base, l, int);
+ XREALLOC(mp->font_sizes, l, pointer);
+ for (f=(mp->last_fnum+1);f<=l;f++) {
+ mp->font_enc_name[f]=NULL;
+ mp->font_ps_name_fixed[f] = false;
+ mp->font_name[f]=NULL;
+ mp->font_ps_name[f]=NULL;
+ mp->font_sizes[f]=null;
+ }
+ mp->font_max = l;
+}
+
+@ @<Internal library declarations@>=
+void mp_reallocate_fonts (MP mp, font_number l);
+
+
+@ A |null_font| containing no characters is useful for error recovery. Its
+|font_name| entry starts out empty but is reset each time an erroneous font is
+found. This helps to cut down on the number of duplicate error messages without
+wasting a lot of space.
+
+@d null_font 0 /* the |font_number| for an empty font */
+
+@<Set initial...@>=
+mp->font_dsize[null_font]=0;
+mp->font_bc[null_font]=1;
+mp->font_ec[null_font]=0;
+mp->char_base[null_font]=0;
+mp->width_base[null_font]=0;
+mp->height_base[null_font]=0;
+mp->depth_base[null_font]=0;
+mp->next_fmem=0;
+mp->last_fnum=null_font;
+mp->last_ps_fnum=null_font;
+mp->font_name[null_font]=(char *)"nullfont";
+mp->font_ps_name[null_font]=(char *)"";
+mp->font_ps_name_fixed[null_font] = false;
+mp->font_enc_name[null_font]=NULL;
+mp->font_sizes[null_font]=null;
+
+@ Each |char_info| word is of type |four_quarters|. The |b0| field contains
+the |width index|; the |b1| field contains the height
+index; the |b2| fields contains the depth index, and the |b3| field used only
+for temporary storage. (It is used to keep track of which characters occur in
+an edge structure that is being shipped out.)
+The corresponding words in the width, height, and depth tables are stored as
+|scaled| values in units of \ps\ points.
+
+With the macros below, the |char_info| word for character~|c| in font~|f| is
+|char_mp_info(f,c)| and the width is
+$$\hbox{|char_width(f,char_mp_info(f,c)).sc|.}$$
+
+@d char_mp_info(A,B) mp->font_info[mp->char_base[(A)]+(B)].qqqq
+@d char_width(A,B) mp->font_info[mp->width_base[(A)]+(B).b0].sc
+@d char_height(A,B) mp->font_info[mp->height_base[(A)]+(B).b1].sc
+@d char_depth(A,B) mp->font_info[mp->depth_base[(A)]+(B).b2].sc
+@d ichar_exists(A) ((A).b0>0)
+
+@ When we have a font name and we don't know whether it has been loaded yet,
+we scan the |font_name| array before calling |read_font_info|.
+
+@<Declarations@>=
+static font_number mp_find_font (MP mp, char *f) ;
+
+@ @c
+font_number mp_find_font (MP mp, char *f) {
+ font_number n;
+ for (n=0;n<=mp->last_fnum;n++) {
+ if (mp_xstrcmp(f,mp->font_name[n])==0 ) {
+ mp_xfree(f);
+ return n;
+ }
+ }
+ n = mp_read_font_info(mp, f);
+ mp_xfree(f);
+ return n;
+}
+
+@ This is an interface function for getting the width of character,
+as a double in ps units
+
+@c double mp_get_char_dimension (MP mp, char *fname, int c, int t) {
+ unsigned n;
+ four_quarters cc;
+ font_number f = 0;
+ double w = -1.0;
+ for (n=0;n<=mp->last_fnum;n++) {
+ if (mp_xstrcmp(fname,mp->font_name[n])==0 ) {
+ f = n;
+ break;
+ }
+ }
+ if (f==0)
+ return 0.0;
+ cc = char_mp_info(f,c);
+ if (! ichar_exists(cc) )
+ return 0.0;
+ if (t=='w')
+ w = (double)char_width(f,cc);
+ else if (t=='h')
+ w = (double)char_height(f,cc);
+ else if (t=='d')
+ w = (double)char_depth(f,cc);
+ return w/655.35*(72.27/72);
+}
+
+@ @<Exported function ...@>=
+double mp_get_char_dimension (MP mp, char *fname, int n, int t);
+
+
+@ One simple application of |find_font| is the implementation of the |font_size|
+operator that gets the design size for a given font name.
+
+@<Find the design size of the font whose name is |cur_exp|@>=
+mp_flush_cur_exp(mp, (mp->font_dsize[mp_find_font(mp, str(mp->cur_exp))]+8) / 16)
+
+@ If we discover that the font doesn't have a requested character, we omit it
+from the bounding box computation and expect the \ps\ interpreter to drop it.
+This routine issues a warning message if the user has asked for it.
+
+@<Declarations@>=
+static void mp_lost_warning (MP mp,font_number f, pool_pointer k);
+
+@ @c
+void mp_lost_warning (MP mp,font_number f, pool_pointer k) {
+ if ( mp->internal[mp_tracing_lost_chars]>0 ) {
+ mp_begin_diagnostic(mp);
+ if ( mp->selector==log_only ) incr(mp->selector);
+ mp_print_nl(mp, "Missing character: There is no ");
+@.Missing character@>
+ mp_print_str(mp, mp->str_pool[k]);
+ mp_print(mp, " in font ");
+ mp_print(mp, mp->font_name[f]); mp_print_char(mp, xord('!'));
+ mp_end_diagnostic(mp, false);
+ }
+}
+
+@ The whole purpose of saving the height, width, and depth information is to be
+able to find the bounding box of an item of text in an edge structure. The
+|set_text_box| procedure takes a text node and adds this information.
+
+@<Declarations@>=
+static void mp_set_text_box (MP mp,pointer p);
+
+@ @c
+void mp_set_text_box (MP mp,pointer p) {
+ font_number f; /* |mp_font_n(p)| */
+ ASCII_code bc,ec; /* range of valid characters for font |f| */
+ pool_pointer k,kk; /* current character and character to stop at */
+ four_quarters cc; /* the |char_info| for the current character */
+ scaled h,d; /* dimensions of the current character */
+ width_val(p)=0;
+ height_val(p)=-el_gordo;
+ depth_val(p)=-el_gordo;
+ f=(font_number)mp_font_n(p);
+ bc=mp->font_bc[f];
+ ec=mp->font_ec[f];
+ kk=str_stop(mp_text_p(p));
+ k=mp->str_start[mp_text_p(p)];
+ while ( k<kk ) {
+ @<Adjust |p|'s bounding box to contain |str_pool[k]|; advance |k|@>;
+ }
+ @<Set the height and depth to zero if the bounding box is empty@>;
+}
+
+@ @<Adjust |p|'s bounding box to contain |str_pool[k]|; advance |k|@>=
+{
+ if ( (mp->str_pool[k]<bc)||(mp->str_pool[k]>ec) ) {
+ mp_lost_warning(mp, f,k);
+ } else {
+ cc=char_mp_info(f,mp->str_pool[k]);
+ if ( ! ichar_exists(cc) ) {
+ mp_lost_warning(mp, f,k);
+ } else {
+ width_val(p)=width_val(p)+char_width(f,cc);
+ h=char_height(f,cc);
+ d=char_depth(f,cc);
+ if ( h>height_val(p) ) height_val(p)=h;
+ if ( d>depth_val(p) ) depth_val(p)=d;
+ }
+ }
+ incr(k);
+}
+
+@ Let's hope modern compilers do comparisons correctly when the difference would
+overflow.
+
+@<Set the height and depth to zero if the bounding box is empty@>=
+if ( height_val(p)<-depth_val(p) ) {
+ height_val(p)=0;
+ depth_val(p)=0;
+}
+
+@ The new primitives fontmapfile and fontmapline.
+
+@<Declare action procedures for use by |do_statement|@>=
+static void mp_do_mapfile (MP mp) ;
+static void mp_do_mapline (MP mp) ;
+
+@ @c
+static void mp_do_mapfile (MP mp) {
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_string_type ) {
+ @<Complain about improper map operation@>;
+ } else {
+ mp_map_file(mp,mp->cur_exp);
+ }
+}
+static void mp_do_mapline (MP mp) {
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_string_type ) {
+ @<Complain about improper map operation@>;
+ } else {
+ mp_map_line(mp,mp->cur_exp);
+ }
+}
+
+@ @<Complain about improper map operation@>=
+{
+ exp_err("Unsuitable expression");
+ help1("Only known strings can be map files or map lines.");
+ mp_put_get_error(mp);
+}
+
+@ To print |scaled| value to PDF output we need some subroutines to ensure
+accurary.
+
+@d max_integer 0x7FFFFFFF /* $2^{31}-1$ */
+
+@<Glob...@>=
+scaled one_bp; /* scaled value corresponds to 1bp */
+scaled one_hundred_bp; /* scaled value corresponds to 100bp */
+scaled one_hundred_inch; /* scaled value corresponds to 100in */
+integer ten_pow[10]; /* $10^0..10^9$ */
+integer scaled_out; /* amount of |scaled| that was taken out in |divide_scaled| */
+
+@ @<Set init...@>=
+mp->one_bp = 65782; /* 65781.76 */
+mp->one_hundred_bp = 6578176;
+mp->one_hundred_inch = 473628672;
+mp->ten_pow[0] = 1;
+for (i = 1;i<= 9; i++ ) {
+ mp->ten_pow[i] = 10*mp->ten_pow[i - 1];
+}
+
+@ The following function divides |s| by |m|. |dd| is number of decimal digits.
+
+@c scaled mp_divide_scaled (MP mp,scaled s, scaled m, integer dd) {
+ scaled q,r;
+ integer sign,i;
+ sign = 1;
+ if ( s < 0 ) { sign = -sign; s = -s; }
+ if ( m < 0 ) { sign = -sign; m = -m; }
+ if ( m == 0 )
+ mp_confusion(mp, "arithmetic: divided by zero");
+ else if ( m >= (max_integer / 10) )
+ mp_confusion(mp, "arithmetic: number too big");
+ q = s / m;
+ r = s % m;
+ for (i = 1;i<=dd;i++) {
+ q = 10*q + (10*r) / m;
+ r = (10*r) % m;
+ }
+ if ( 2*r >= m ) { incr(q); r = r - m; }
+ mp->scaled_out = sign*(s - (r / mp->ten_pow[dd]));
+ return (sign*q);
+}
+
+@* \[44] Shipping pictures out.
+The |ship_out| procedure, to be described below, is given a pointer to
+an edge structure. Its mission is to output a file containing the \ps\
+description of an edge structure.
+
+@ Each time an edge structure is shipped out we write a new \ps\ output
+file named according to the current \&{charcode}.
+@:char_code_}{\&{charcode} primitive@>
+
+This is the only backend function that remains in the main |mpost.w| file.
+There are just too many variable accesses needed for status reporting
+etcetera to make it worthwile to move the code to |psout.w|.
+
+@<Internal library declarations@>=
+void mp_open_output_file (MP mp) ;
+
+@ @c
+static char *mp_set_output_file_name (MP mp, integer c) {
+ char *ss = NULL; /* filename extension proposal */
+ char *nn = NULL; /* temp string for str() */
+ unsigned old_setting; /* previous |selector| setting */
+ pool_pointer i; /* indexes into |filename_template| */
+ integer cc; /* a temporary integer for template building */
+ integer f,g=0; /* field widths */
+ if ( mp->job_name==NULL ) mp_open_log_file(mp);
+ if ( mp->internal[mp_output_template]==0) {
+ char *s; /* a file extension derived from |c| */
+ if ( c<0 )
+ s=xstrdup(".ps");
+ else
+ @<Use |c| to compute the file extension |s|@>;
+ mp_pack_job_name(mp, s);
+ free(s);
+ ss = xstrdup(mp->name_of_file);
+ } else { /* initializations */
+ str_number s, n; /* a file extension derived from |c| */
+ old_setting=mp->selector;
+ mp->selector=new_string;
+ f = 0;
+ i = mp->str_start[mp->internal[mp_output_template]];
+ n = null_str; /* initialize */
+ while ( i<str_stop(mp->internal[mp_output_template]) ) {
+ if ( mp->str_pool[i]=='%' ) {
+ CONTINUE:
+ incr(i);
+ if ( i<str_stop(mp->internal[mp_output_template]) ) {
+ if ( mp->str_pool[i]=='j' ) {
+ mp_print(mp, mp->job_name);
+ } else if ( mp->str_pool[i]=='o' ) {
+ { char *s;
+ s = str(mp->internal[mp_output_format]);
+ mp_print(mp, s);
+ mp_xfree(s);
+ }
+ } else if ( mp->str_pool[i]=='d' ) {
+ cc= mp_round_unscaled(mp, mp->internal[mp_day]);
+ print_with_leading_zeroes(cc);
+ } else if ( mp->str_pool[i]=='m' ) {
+ cc= mp_round_unscaled(mp, mp->internal[mp_month]);
+ print_with_leading_zeroes(cc);
+ } else if ( mp->str_pool[i]=='y' ) {
+ cc= mp_round_unscaled(mp, mp->internal[mp_year]);
+ print_with_leading_zeroes(cc);
+ } else if ( mp->str_pool[i]=='H' ) {
+ cc= mp_round_unscaled(mp, mp->internal[mp_time]) / 60;
+ print_with_leading_zeroes(cc);
+ } else if ( mp->str_pool[i]=='M' ) {
+ cc= mp_round_unscaled(mp, mp->internal[mp_time]) % 60;
+ print_with_leading_zeroes(cc);
+ } else if ( mp->str_pool[i]=='c' ) {
+ if ( c<0 ) mp_print(mp, "ps");
+ else print_with_leading_zeroes(c);
+ } else if ( (mp->str_pool[i]>='0') &&
+ (mp->str_pool[i]<='9') ) {
+ if ( (f<10) )
+ f = (f*10) + mp->str_pool[i]-'0';
+ goto CONTINUE;
+ } else {
+ mp_print_str(mp, mp->str_pool[i]);
+ }
+ }
+ } else {
+ if ( mp->str_pool[i]=='.' )
+ if (length(n)==0)
+ n = mp_make_string(mp);
+ mp_print_str(mp, mp->str_pool[i]);
+ };
+ incr(i);
+ }
+ s = mp_make_string(mp);
+ mp->selector= old_setting;
+ if (length(n)==0) {
+ n=s;
+ s=null_str;
+ }
+ ss = str(s);
+ nn = str(n);
+ mp_pack_file_name(mp, nn,"",ss);
+ free(nn);
+ delete_str_ref(n);
+ delete_str_ref(s);
+ }
+ return ss;
+}
+
+static char * mp_get_output_file_name (MP mp) {
+ char *f;
+ char *saved_name; /* saved |name_of_file| */
+ saved_name = xstrdup(mp->name_of_file);
+ f = xstrdup(mp_set_output_file_name(mp, mp_round_unscaled(mp, mp->internal[mp_char_code])));
+ mp_pack_file_name(mp, saved_name,NULL,NULL);
+ free(saved_name);
+ return f;
+}
+
+void mp_open_output_file (MP mp) {
+ char *ss; /* filename extension proposal */
+ integer c; /* \&{charcode} rounded to the nearest integer */
+ c=mp_round_unscaled(mp, mp->internal[mp_char_code]);
+ ss = mp_set_output_file_name(mp, c);
+ while ( ! mp_a_open_out(mp, (void *)&mp->output_file, mp_filetype_postscript) )
+ mp_prompt_file_name(mp, "file name for output",ss);
+ xfree(ss);
+ @<Store the true output file name if appropriate@>;
+}
+
+@ The file extension created here could be up to five characters long in
+extreme cases so it may have to be shortened on some systems.
+@^system dependencies@>
+
+@<Use |c| to compute the file extension |s|@>=
+{
+ s = xmalloc(7,1);
+ mp_snprintf(s,7,".%i",(int)c);
+}
+
+@ The user won't want to see all the output file names so we only save the
+first and last ones and a count of how many there were. For this purpose
+files are ordered primarily by \&{charcode} and secondarily by order of
+creation.
+@:char_code_}{\&{charcode} primitive@>
+
+@<Store the true output file name if appropriate@>=
+if ((c<mp->first_output_code)&&(mp->first_output_code>=0)) {
+ mp->first_output_code=c;
+ xfree(mp->first_file_name);
+ mp->first_file_name=xstrdup(mp->name_of_file);
+}
+if ( c>=mp->last_output_code ) {
+ mp->last_output_code=c;
+ xfree(mp->last_file_name);
+ mp->last_file_name=xstrdup(mp->name_of_file);
+}
+
+@ @<Glob...@>=
+char * first_file_name;
+char * last_file_name; /* full file names */
+integer first_output_code;integer last_output_code; /* rounded \&{charcode} values */
+@:char_code_}{\&{charcode} primitive@>
+integer total_shipped; /* total number of |ship_out| operations completed */
+
+@ @<Set init...@>=
+mp->first_file_name=xstrdup("");
+mp->last_file_name=xstrdup("");
+mp->first_output_code=32768;
+mp->last_output_code=-32768;
+mp->total_shipped=0;
+
+@ @<Dealloc variables@>=
+xfree(mp->first_file_name);
+xfree(mp->last_file_name);
+
+@ @<Begin the progress report for the output of picture~|c|@>=
+if ( (int)mp->term_offset>mp->max_print_line-6 ) mp_print_ln(mp);
+else if ( (mp->term_offset>0)||(mp->file_offset>0) ) mp_print_char(mp, xord(' '));
+mp_print_char(mp, xord('['));
+if ( c>=0 ) mp_print_int(mp, c)
+
+@ @<End progress report@>=
+mp_print_char(mp, xord(']'));
+update_terminal;
+incr(mp->total_shipped)
+
+@ @<Explain what output files were written@>=
+if ( mp->total_shipped>0 ) {
+ mp_print_nl(mp, "");
+ mp_print_int(mp, mp->total_shipped);
+ if (mp->noninteractive) {
+ mp_print(mp, " figure");
+ if ( mp->total_shipped>1 ) mp_print_char(mp, xord('s'));
+ mp_print(mp, " created.");
+ } else {
+ mp_print(mp, " output file");
+ if ( mp->total_shipped>1 ) mp_print_char(mp, xord('s'));
+ mp_print(mp, " written: ");
+ mp_print(mp, mp->first_file_name);
+ if ( mp->total_shipped>1 ) {
+ if ( 31+strlen(mp->first_file_name)+
+ strlen(mp->last_file_name)> (unsigned)mp->max_print_line)
+ mp_print_ln(mp);
+ mp_print(mp, " .. ");
+ mp_print(mp, mp->last_file_name);
+ }
+ }
+}
+
+@ @<Internal library declarations@>=
+boolean mp_has_font_size(MP mp, font_number f );
+
+@ @c
+boolean mp_has_font_size(MP mp, font_number f ) {
+ return (mp->font_sizes[f]!=null);
+}
+
+@ The \&{special} command saves up lines of text to be printed during the next
+|ship_out| operation. The saved items are stored as a list of capsule tokens.
+
+@<Glob...@>=
+pointer last_pending; /* the last token in a list of pending specials */
+
+@ @<Set init...@>=
+mp->last_pending=spec_head;
+
+@ @<Cases of |do_statement|...@>=
+case special_command:
+ if ( mp->cur_mod==0 ) mp_do_special(mp); else
+ if ( mp->cur_mod==1 ) mp_do_mapfile(mp); else
+ mp_do_mapline(mp);
+ break;
+
+@ @<Declare action procedures for use by |do_statement|@>=
+static void mp_do_special (MP mp) ;
+
+@ @c void mp_do_special (MP mp) {
+ mp_get_x_next(mp); mp_scan_expression(mp);
+ if ( mp->cur_type!=mp_string_type ) {
+ @<Complain about improper special operation@>;
+ } else {
+ mp_link(mp->last_pending)=mp_stash_cur_exp(mp);
+ mp->last_pending=mp_link(mp->last_pending);
+ mp_link(mp->last_pending)=null;
+ }
+}
+
+@ @<Complain about improper special operation@>=
+{
+ exp_err("Unsuitable expression");
+ help1("Only known strings are allowed for output as specials.");
+ mp_put_get_error(mp);
+}
+
+@ On the export side, we need an extra object type for special strings.
+
+@<Graphical object codes@>=
+mp_special_code=8,
+
+@ @<Export pending specials@>=
+p=mp_link(spec_head);
+while ( p!=null ) {
+ mp_special_object *tp;
+ tp = (mp_special_object *)mp_new_graphic_object(mp,mp_special_code);
+ gr_pre_script(tp) = str(value(p));
+ if (hh->body==NULL) hh->body = (mp_graphic_object *)tp;
+ else gr_link(hp) = (mp_graphic_object *)tp;
+ hp = (mp_graphic_object *)tp;
+ p=mp_link(p);
+}
+mp_flush_token_list(mp, mp_link(spec_head));
+mp_link(spec_head)=null;
+mp->last_pending=spec_head
+
+@ We are now ready for the main output procedure. Note that the |selector|
+setting is saved in a global variable so that |begin_diagnostic| can access it.
+
+@<Declare the \ps\ output procedures@>=
+static void mp_ship_out (MP mp, pointer h) ;
+
+@ Once again, the |gr_XXXX| macros are defined in |mppsout.h|
+
+@d export_color(q,p)
+ if ( mp_color_model(p)==mp_uninitialized_model ) {
+ gr_color_model(q) = (unsigned char)(mp->internal[mp_default_color_model]/65536);
+ gr_cyan_val(q) = 0;
+ gr_magenta_val(q) = 0;
+ gr_yellow_val(q) = 0;
+ gr_black_val(q) = (gr_color_model(q)==mp_cmyk_model ? unity : 0);
+ } else {
+ gr_color_model(q) = (unsigned char)mp_color_model(p);
+ gr_cyan_val(q) = cyan_val(p);
+ gr_magenta_val(q) = magenta_val(p);
+ gr_yellow_val(q) = yellow_val(p);
+ gr_black_val(q) = black_val(p);
+ }
+
+@d export_scripts(q,p)
+ if (mp_pre_script(p)!=null) gr_pre_script(q) = str(mp_pre_script(p));
+ if (mp_post_script(p)!=null) gr_post_script(q) = str(mp_post_script(p));
+
+@c
+struct mp_edge_object *mp_gr_export(MP mp, pointer h) {
+ pointer p; /* the current graphical object */
+ integer t; /* a temporary value */
+ integer c; /* a rounded charcode */
+ scaled d_width; /* the current pen width */
+ mp_edge_object *hh; /* the first graphical object */
+ mp_graphic_object *hq; /* something |hp| points to */
+ mp_text_object *tt;
+ mp_fill_object *tf;
+ mp_stroked_object *ts;
+ mp_clip_object *tc;
+ mp_bounds_object *tb;
+ mp_graphic_object *hp = NULL; /* the current graphical object */
+ mp_set_bbox(mp, h, true);
+ hh = xmalloc(1,sizeof(mp_edge_object));
+ hh->body = NULL;
+ hh->next = NULL;
+ hh->parent = mp;
+ hh->minx = minx_val(h);
+ hh->miny = miny_val(h);
+ hh->maxx = maxx_val(h);
+ hh->maxy = maxy_val(h);
+ hh->filename = mp_get_output_file_name(mp);
+ c = mp_round_unscaled(mp,mp->internal[mp_char_code]);
+ hh->charcode = c;
+ hh->width = mp->internal[mp_char_wd];
+ hh->height = mp->internal[mp_char_ht];
+ hh->depth = mp->internal[mp_char_dp];
+ hh->ital_corr = mp->internal[mp_char_ic];
+ @<Export pending specials@>;
+ p=mp_link(dummy_loc(h));
+ while ( p!=null ) {
+ hq = mp_new_graphic_object(mp,mp_type(p));
+ switch (mp_type(p)) {
+ case mp_fill_code:
+ tf = (mp_fill_object *)hq;
+ gr_pen_p(tf) = mp_export_knot_list(mp,mp_pen_p(p));
+ d_width = mp_get_pen_scale(mp, mp_pen_p(p));
+ if ((mp_pen_p(p)==null) || pen_is_elliptical(mp_pen_p(p))) {
+ gr_path_p(tf) = mp_export_knot_list(mp,mp_path_p(p));
+ } else {
+ pointer pc, pp;
+ pc = mp_copy_path(mp, mp_path_p(p));
+ pp = mp_make_envelope(mp, pc, mp_pen_p(p),ljoin_val(p),0,miterlim_val(p));
+ gr_path_p(tf) = mp_export_knot_list(mp,pp);
+ mp_toss_knot_list(mp, pp);
+ pc = mp_htap_ypoc(mp, mp_path_p(p));
+ pp = mp_make_envelope(mp, pc, mp_pen_p(p),ljoin_val(p),0,miterlim_val(p));
+ gr_htap_p(tf) = mp_export_knot_list(mp,pp);
+ mp_toss_knot_list(mp, pp);
+ }
+ export_color(tf,p) ;
+ export_scripts(tf,p);
+ gr_ljoin_val(tf) = (unsigned char)ljoin_val(p);
+ gr_miterlim_val(tf) = miterlim_val(p);
+ break;
+ case mp_stroked_code:
+ ts = (mp_stroked_object *)hq;
+ gr_pen_p(ts) = mp_export_knot_list(mp,mp_pen_p(p));
+ d_width = mp_get_pen_scale(mp, mp_pen_p(p));
+ if (pen_is_elliptical(mp_pen_p(p))) {
+ gr_path_p(ts) = mp_export_knot_list(mp,mp_path_p(p));
+ } else {
+ pointer pc;
+ pc=mp_copy_path(mp, mp_path_p(p));
+ t=lcap_val(p);
+ if ( mp_left_type(pc)!=mp_endpoint ) {
+ mp_left_type(mp_insert_knot(mp, pc,mp_x_coord(pc),mp_y_coord(pc)))=mp_endpoint;
+ mp_right_type(pc)=mp_endpoint;
+ pc=mp_link(pc);
+ t=1;
+ }
+ pc=mp_make_envelope(mp,pc,mp_pen_p(p),ljoin_val(p),t,miterlim_val(p));
+ gr_path_p(ts) = mp_export_knot_list(mp,pc);
+ mp_toss_knot_list(mp, pc);
+ }
+ export_color(ts,p) ;
+ export_scripts(ts,p);
+ gr_ljoin_val(ts) = (unsigned char)ljoin_val(p);
+ gr_miterlim_val(ts) = miterlim_val(p);
+ gr_lcap_val(ts) = (unsigned char)lcap_val(p);
+ gr_dash_p(ts) = mp_export_dashes(mp,p,&d_width);
+ break;
+ case mp_text_code:
+ tt = (mp_text_object *)hq;
+ gr_text_p(tt) = str(mp_text_p(p));
+ gr_text_l(tt) = (size_t)length(mp_text_p(p));
+ gr_font_n(tt) = (unsigned int)mp_font_n(p);
+ gr_font_name(tt) = mp_xstrdup(mp,mp->font_name[mp_font_n(p)]);
+ gr_font_dsize(tt) = (unsigned int)mp->font_dsize[mp_font_n(p)];
+ export_color(tt,p) ;
+ export_scripts(tt,p);
+ gr_width_val(tt) = width_val(p);
+ gr_height_val(tt) = height_val(p);
+ gr_depth_val(tt) = depth_val(p);
+ gr_tx_val(tt) = tx_val(p);
+ gr_ty_val(tt) = ty_val(p);
+ gr_txx_val(tt) = txx_val(p);
+ gr_txy_val(tt) = txy_val(p);
+ gr_tyx_val(tt) = tyx_val(p);
+ gr_tyy_val(tt) = tyy_val(p);
+ break;
+ case mp_start_clip_code:
+ tc = (mp_clip_object *)hq;
+ gr_path_p(tc) = mp_export_knot_list(mp,mp_path_p(p));
+ break;
+ case mp_start_bounds_code:
+ tb = (mp_bounds_object *)hq;
+ gr_path_p(tb) = mp_export_knot_list(mp,mp_path_p(p));
+ break;
+ case mp_stop_clip_code:
+ case mp_stop_bounds_code:
+ /* nothing to do here */
+ break;
+ }
+ if (hh->body==NULL) hh->body=hq; else gr_link(hp) = hq;
+ hp = hq;
+ p=mp_link(p);
+ }
+ return hh;
+}
+
+@ @<Declarations@>=
+static struct mp_edge_object *mp_gr_export(MP mp, int h);
+
+@ This function is now nearly trivial.
+
+@c
+void mp_ship_out (MP mp, pointer h) { /* output edge structure |h| */
+ integer c; /* \&{charcode} rounded to the nearest integer */
+ c=mp_round_unscaled(mp, mp->internal[mp_char_code]);
+ @<Begin the progress report for the output of picture~|c|@>;
+ (mp->shipout_backend) (mp, h);
+ @<End progress report@>;
+ if ( mp->internal[mp_tracing_output]>0 )
+ mp_print_edges(mp, h," (just shipped out)",true);
+}
+
+@ @<Declarations@>=
+static void mp_shipout_backend (MP mp, pointer h);
+
+@
+@c
+void mp_shipout_backend (MP mp, pointer h) {
+ char *s;
+ mp_edge_object *hh; /* the first graphical object */
+ hh = mp_gr_export(mp,h);
+ s = NULL;
+ if (mp->internal[mp_output_format]>0)
+ s = str(mp->internal[mp_output_format]);
+ if (s && strcmp(s,"svg")==0) {
+ (void)mp_svg_gr_ship_out (hh,
+ (mp->internal[mp_prologues]/65536),
+ false);
+ } else {
+ (void)mp_gr_ship_out (hh,
+ (mp->internal[mp_prologues]/65536),
+ (mp->internal[mp_procset]/65536),
+ false);
+ }
+ mp_gr_toss_objects(hh);
+}
+
+@ @<Exported types@>=
+typedef void (*mp_backend_writer)(MP, int);
+
+@ @<Option variables@>=
+mp_backend_writer shipout_backend;
+
+@ Now that we've finished |ship_out|, let's look at the other commands
+by which a user can send things to the \.{GF} file.
+
+@ @<Determine if a character has been shipped out@>=
+{
+ mp->cur_exp=mp_round_unscaled(mp, mp->cur_exp) % 256;
+ if ( mp->cur_exp<0 ) mp->cur_exp=mp->cur_exp+256;
+ boolean_reset(mp->char_exists[mp->cur_exp]);
+ mp->cur_type=mp_boolean_type;
+}
+
+@ @<Glob...@>=
+psout_data ps;
+svgout_data svg;
+
+@ @<Allocate or initialize ...@>=
+mp_ps_backend_initialize(mp);
+mp_svg_backend_initialize(mp);
+
+@ @<Dealloc...@>=
+mp_ps_backend_free(mp);
+mp_svg_backend_free(mp);
+
+
+@* \[45] Dumping and undumping the tables.
+After \.{INIMP} has seen a collection of macros, it
+can write all the necessary information on an auxiliary file so
+that production versions of \MP\ are able to initialize their
+memory at high speed. The present section of the program takes
+care of such output and input. We shall consider simultaneously
+the processes of storing and restoring,
+so that the inverse relation between them is clear.
+@.INIMP@>
+
+The global variable |mem_ident| is a string that is printed right
+after the |banner| line when \MP\ is ready to start. For \.{INIMP} this
+string says simply `\.{(INIMP)}'; for other versions of \MP\ it says,
+for example, `\.{(mem=plain 1990.4.14)}', showing the year,
+month, and day that the mem file was created. We have |mem_ident=0|
+before \MP's tables are loaded.
+
+@<Glob...@>=
+char * mem_ident;
+void * mem_file; /* for input or output of mem information */
+
+@ @<Set init...@>=
+mp->mem_ident=NULL;
+
+@ @<Initialize table entries...@>=
+mp->mem_ident=xstrdup(" (INIMP)");
+
+@ @<Declarations@>=
+extern void mp_store_mem_file (MP mp) ;
+extern boolean mp_load_mem_file (MP mp);
+extern int mp_undump_constants (MP mp);
+
+@ @<Dealloc variables@>=
+xfree(mp->mem_ident);
+
+
+@* \[46] The main program.
+This is it: the part of \MP\ that executes all those procedures we have
+written.
+
+Well---almost. We haven't put the parsing subroutines into the
+program yet; and we'd better leave space for a few more routines that may
+have been forgotten.
+
+@c @<Declare the basic parsing subroutines@>
+@<Declare miscellaneous procedures that were declared |forward|@>
+
+@ We've noted that there are two versions of \MP. One, called \.{INIMP},
+@.INIMP@>
+has to be run first; it initializes everything from scratch, without
+reading a mem file, and it has the capability of dumping a mem file.
+The other one is called `\.{VIRMP}'; it is a ``virgin'' program that needs
+@.VIRMP@>
+to input a mem file in order to get started. \.{VIRMP} typically has
+a bit more memory capacity than \.{INIMP}, because it does not need the
+space consumed by the dumping/undumping routines and the numerous calls on
+|primitive|, etc.
+
+The \.{VIRMP} program cannot read a mem file instantaneously, of course;
+the best implementations therefore allow for production versions of \MP\ that
+not only avoid the loading routine for object code, they also have
+a mem file pre-loaded.
+
+@ @<Option variables@>=
+int ini_version; /* are we iniMP? */
+
+@ @<Set |ini_version|@>=
+mp->ini_version = (opt->ini_version ? true : false);
+
+@ The code below make the final chosen hash size the next larger
+multiple of 2 from the requested size, and this array is a list of
+suitable prime numbers to go with such values.
+
+The top limit is chosen such that it is definately lower than
+|max_halfword-3*param_size|, because |param_size| cannot be larger
+than |max_halfword/sizeof(pointer)|.
+
+@<Declarations@>=
+static int mp_prime_choices[] =
+ { 12289, 24593, 49157, 98317,
+ 196613, 393241, 786433, 1572869,
+ 3145739, 6291469, 12582917, 25165843,
+ 50331653, 100663319 };
+
+@ @<Find constant sizes@>=
+if (mp->ini_version) {
+ unsigned i = 14;
+ set_value(mp->mem_top,opt->main_memory,5000);
+ mp->mem_max = mp->mem_top;
+ set_value(mp->param_size,opt->param_size,150);
+ set_value(mp->max_in_open,opt->max_in_open,10);
+ if (opt->hash_size>0x8000000)
+ opt->hash_size=0x8000000;
+ if (opt->hash_size>0) {
+ set_value(mp->hash_size,(2*opt->hash_size-1),16384);
+ } else {
+ mp->hash_size = 16384;
+ }
+ mp->hash_size = mp->hash_size>>i;
+ while (mp->hash_size>=2) {
+ mp->hash_size /= 2;
+ i++;
+ }
+ mp->hash_size = mp->hash_size << i;
+ if (mp->hash_size>0x8000000)
+ mp->hash_size=0x8000000;
+ mp->hash_prime=mp_prime_choices[(i-14)];
+} else {
+ int i = -1;
+ if (mp->mem_name == NULL) {
+ mp->mem_name = mp_xstrdup(mp,"plain");
+ }
+ if (mp_open_mem_file(mp)) {
+ i = mp_undump_constants(mp);
+ if (i != metapost_magic)
+ goto OFF_BASE;
+ set_value(mp->mem_max,opt->main_memory,mp->mem_top);
+ goto DONE;
+OFF_BASE:
+ wterm_ln("(Fatal mem file error; ");
+ wterm((mp->find_file)(mp, mp->mem_name, "r", mp_filetype_memfile));
+ if (i>metapost_old_magic && i<metapost_magic) {
+ wterm(" was written by an older version)\n");
+ } else {
+ wterm(" appears not to be a mem file)\n");
+ }
+ }
+ mp->history = mp_fatal_error_stop;
+ mp_jump_out(mp);
+}
+DONE:
+
+
+@ Here we do whatever is needed to complete \MP's job gracefully on the
+local operating system. The code here might come into play after a fatal
+error; it must therefore consist entirely of ``safe'' operations that
+cannot produce error messages. For example, it would be a mistake to call
+|str_room| or |make_string| at this time, because a call on |overflow|
+might lead to an infinite loop.
+@^system dependencies@>
+
+This program doesn't bother to close the input files that may still be open.
+
+@ @c
+void mp_close_files_and_terminate (MP mp) {
+ integer k; /* all-purpose index */
+ integer LH; /* the length of the \.{TFM} header, in words */
+ int lk_offset; /* extra words inserted at beginning of |lig_kern| array */
+ pointer p; /* runs through a list of \.{TFM} dimensions */
+ if (mp->finished)
+ return;
+ @<Close all open files in the |rd_file| and |wr_file| arrays@>;
+ if ( mp->internal[mp_tracing_stats]>0 )
+ @<Output statistics about this job@>;
+ wake_up_terminal;
+ @<Do all the finishing work on the \.{TFM} file@>;
+ @<Explain what output files were written@>;
+ if ( mp->log_opened && ! mp->noninteractive ){
+ wlog_cr;
+ (mp->close_file)(mp,mp->log_file);
+ mp->selector=mp->selector-2;
+ if ( mp->selector==term_only ) {
+ mp_print_nl(mp, "Transcript written on ");
+@.Transcript written...@>
+ mp_print(mp, mp->log_name); mp_print_char(mp, xord('.'));
+ }
+ }
+ mp_print_ln(mp);
+ mp->finished = true;
+}
+
+@ @<Declarations@>=
+static void mp_close_files_and_terminate (MP mp) ;
+
+@ @<Close all open files in the |rd_file| and |wr_file| arrays@>=
+if (mp->rd_fname!=NULL) {
+ for (k=0;k<(int)mp->read_files;k++ ) {
+ if ( mp->rd_fname[k]!=NULL ) {
+ (mp->close_file)(mp,mp->rd_file[k]);
+ xfree(mp->rd_fname[k]);
+ }
+ }
+}
+if (mp->wr_fname!=NULL) {
+ for (k=0;k<(int)mp->write_files;k++) {
+ if ( mp->wr_fname[k]!=NULL ) {
+ (mp->close_file)(mp,mp->wr_file[k]);
+ xfree(mp->wr_fname[k]);
+ }
+ }
+}
+
+@ @<Dealloc ...@>=
+for (k=0;k<(int)mp->max_read_files;k++ ) {
+ if ( mp->rd_fname[k]!=NULL ) {
+ (mp->close_file)(mp,mp->rd_file[k]);
+ xfree(mp->rd_fname[k]);
+ }
+}
+xfree(mp->rd_file);
+xfree(mp->rd_fname);
+for (k=0;k<(int)mp->max_write_files;k++) {
+ if ( mp->wr_fname[k]!=NULL ) {
+ (mp->close_file)(mp,mp->wr_file[k]);
+ xfree(mp->wr_fname[k]);
+ }
+}
+xfree(mp->wr_file);
+xfree(mp->wr_fname);
+
+
+@ We want to produce a \.{TFM} file if and only if |mp_fontmaking| is positive.
+
+We reclaim all of the variable-size memory at this point, so that
+there is no chance of another memory overflow after the memory capacity
+has already been exceeded.
+
+@<Do all the finishing work on the \.{TFM} file@>=
+if ( mp->internal[mp_fontmaking]>0 ) {
+ @<Make the dynamic memory into one big available node@>;
+ @<Massage the \.{TFM} widths@>;
+ mp_fix_design_size(mp); mp_fix_check_sum(mp);
+ @<Massage the \.{TFM} heights, depths, and italic corrections@>;
+ mp->internal[mp_fontmaking]=0; /* avoid loop in case of fatal error */
+ @<Finish the \.{TFM} file@>;
+}
+
+@ @<Make the dynamic memory into one big available node@>=
+mp->rover=lo_mem_stat_max+1; mp_link(mp->rover)=empty_flag; mp->lo_mem_max=mp->hi_mem_min-1;
+if ( mp->lo_mem_max-mp->rover>max_halfword ) mp->lo_mem_max=max_halfword+mp->rover;
+node_size(mp->rover)=mp->lo_mem_max-mp->rover;
+lmp_link(mp->rover)=mp->rover; rmp_link(mp->rover)=mp->rover;
+mp_link(mp->lo_mem_max)=null; mp_info(mp->lo_mem_max)=null
+
+@ The present section goes directly to the log file instead of using
+|print| commands, because there's no need for these strings to take
+up |str_pool| memory when a non-{\bf stat} version of \MP\ is being used.
+
+@<Output statistics...@>=
+if ( mp->log_opened ) {
+ char s[128];
+ wlog_ln(" ");
+ wlog_ln("Here is how much of MetaPost's memory you used:");
+@.Here is how much...@>
+ mp_snprintf(s,128," %i string%s out of %i",(int)mp->max_strs_used-mp->init_str_use,
+ (mp->max_strs_used!=mp->init_str_use+1 ? "s" : ""),
+ (int)(mp->max_strings-1-mp->init_str_use));
+ wlog_ln(s);
+ mp_snprintf(s,128," %i string characters out of %i",
+ (int)mp->max_pl_used-mp->init_pool_ptr,
+ (int)mp->pool_size-mp->init_pool_ptr);
+ wlog_ln(s);
+ mp_snprintf(s,128," %i words of memory out of %i",
+ (int)mp->lo_mem_max+mp->mem_end-mp->hi_mem_min+2,
+ (int)mp->mem_end);
+ wlog_ln(s);
+ mp_snprintf(s,128," %i symbolic tokens out of %i", (int)mp->st_count, (int)mp->hash_size);
+ wlog_ln(s);
+ mp_snprintf(s,128," %ii,%in,%ip,%ib,%if stack positions out of %ii,%in,%ip,%ib,%if",
+ (int)mp->max_in_stack,(int)mp->int_ptr,
+ (int)mp->max_param_stack,(int)mp->max_buf_stack+1,(int)mp->in_open_max,
+ (int)mp->stack_size,(int)mp->max_internal,(int)mp->param_size,
+ (int)mp->buf_size,(int)mp->max_in_open);
+ wlog_ln(s);
+ mp_snprintf(s,128," %i string compactions (moved %i characters, %i strings)",
+ (int)mp->pact_count,(int)mp->pact_chars,(int)mp->pact_strs);
+ wlog_ln(s);
+}
+
+@ It is nice to have have some of the stats available from the API.
+
+@<Exported function ...@>=
+int mp_memory_usage (MP mp );
+int mp_hash_usage (MP mp );
+int mp_param_usage (MP mp );
+int mp_open_usage (MP mp );
+
+@ @c
+int mp_memory_usage (MP mp ) {
+ return (int)mp->lo_mem_max+mp->mem_end-mp->hi_mem_min+2;
+}
+int mp_hash_usage (MP mp ) {
+ return (int)mp->st_count;
+}
+int mp_param_usage (MP mp ) {
+ return (int)mp->max_param_stack;
+}
+int mp_open_usage (MP mp ) {
+ return (int)mp->max_in_stack;
+}
+
+@ We get to the |final_cleanup| routine when \&{end} or \&{dump} has
+been scanned.
+
+@c
+void mp_final_cleanup (MP mp) {
+ quarterword c; /* 0 for \&{end}, 1 for \&{dump} */
+ c=mp->cur_mod;
+ if ( mp->job_name==NULL ) mp_open_log_file(mp);
+ while ( mp->input_ptr>0 ) {
+ if ( token_state ) mp_end_token_list(mp);
+ else mp_end_file_reading(mp);
+ }
+ while ( mp->loop_ptr!=null ) mp_stop_iteration(mp);
+ while ( mp->open_parens>0 ) {
+ mp_print(mp, " )"); decr(mp->open_parens);
+ };
+ while ( mp->cond_ptr!=null ) {
+ mp_print_nl(mp, "(end occurred when ");
+@.end occurred...@>
+ mp_print_cmd_mod(mp, fi_or_else,mp->cur_if);
+ /* `\.{if}' or `\.{elseif}' or `\.{else}' */
+ if ( mp->if_line!=0 ) {
+ mp_print(mp, " on line "); mp_print_int(mp, mp->if_line);
+ }
+ mp_print(mp, " was incomplete)");
+ mp->if_line=if_line_field(mp->cond_ptr);
+ mp->cur_if=mp_name_type(mp->cond_ptr); mp->cond_ptr=mp_link(mp->cond_ptr);
+ }
+ if ( mp->history!=mp_spotless )
+ if ( ((mp->history==mp_warning_issued)||(mp->interaction<mp_error_stop_mode)) )
+ if ( mp->selector==term_and_log ) {
+ mp->selector=term_only;
+ mp_print_nl(mp, "(see the transcript file for additional information)");
+@.see the transcript file...@>
+ mp->selector=term_and_log;
+ }
+ if ( c==1 ) {
+ if (mp->ini_version) {
+ mp_store_mem_file(mp); return;
+ }
+ mp_print_nl(mp, "(dump is performed only by INIMP)"); return;
+@.dump...only by INIMP@>
+ }
+}
+
+@ @<Declarations@>=
+static void mp_final_cleanup (MP mp) ;
+static void mp_init_prim (MP mp) ;
+static void mp_init_tab (MP mp) ;
+
+@ @c
+void mp_init_prim (MP mp) { /* initialize all the primitives */
+ @<Put each...@>;
+}
+@#
+void mp_init_tab (MP mp) { /* initialize other tables */
+ integer k; /* all-purpose index */
+ @<Initialize table entries (done by \.{INIMP} only)@>;
+}
+
+
+@ When we begin the following code, \MP's tables may still contain garbage;
+thus we must proceed cautiously to get bootstrapped in.
+
+But when we finish this part of the program, \MP\ is ready to call on the
+|main_control| routine to do its work.
+
+@<Get the first line...@>=
+{
+ @<Initialize the input routines@>;
+ if (mp->mem_ident==NULL) {
+ if ( ! mp_load_mem_file(mp) ) {
+ (mp->close_file)(mp, mp->mem_file);
+ mp->history = mp_fatal_error_stop;
+ return mp;
+ }
+ (mp->close_file)(mp, mp->mem_file);
+ }
+ @<Initializations following first line@>;
+}
+
+@ @<Initializations following first line@>=
+ mp->buffer[limit]=(ASCII_code)'%';
+ mp_fix_date_and_time(mp);
+ if (mp->random_seed==0)
+ mp->random_seed = (mp->internal[mp_time] / unity)+mp->internal[mp_day];
+ mp_init_randoms(mp, mp->random_seed);
+ @<Initialize the print |selector|...@>;
+ if ( loc<limit ) if ( mp->buffer[loc]!='\\' )
+ mp_start_input(mp); /* \&{input} assumed */
+
+@ @<Run inimpost commands@>=
+{
+ mp_get_strings_started(mp);
+ mp_init_tab(mp); /* initialize the tables */
+ mp_init_prim(mp); /* call |primitive| for each primitive */
+ mp->init_str_use=mp->max_str_ptr=mp->str_ptr;
+ mp->init_pool_ptr=mp->max_pool_ptr=mp->pool_ptr;
+ mp_fix_date_and_time(mp);
+}
+
+@ Saving the filename template
+
+@<Save the filename template@>=
+{
+ delete_str_ref(mp->internal[mp_output_template]);
+ if ( length(mp->cur_exp)==0 ) {
+ mp->internal[mp_output_template] = rts("%j.%c");
+ } else {
+ mp->internal[mp_output_template]=mp->cur_exp;
+ add_str_ref(mp->internal[mp_output_template]);
+ }
+}
+
+@* \[47] Debugging.
+
+
+@* \[48] System-dependent changes.
+This section should be replaced, if necessary, by any special
+modification of the program
+that are necessary to make \MP\ work at a particular installation.
+It is usually best to design your change file so that all changes to
+previous sections preserve the section numbering; then everybody's version
+will be consistent with the published program. More extensive changes,
+which introduce new sections, can be inserted here; then only the index
+itself will get a new section number.
+@^system dependencies@>
+
+@* \[49] Index.
+Here is where you can find all uses of each identifier in the program,
+with underlined entries pointing to where the identifier was defined.
+If the identifier is only one letter long, however, you get to see only
+the underlined entries. {\sl All references are to section numbers instead of
+page numbers.}
+
+This index also lists error messages and other aspects of the program
+that you might want to look up some day. For example, the entry
+for ``system dependencies'' lists all sections that should receive
+special attention from people who are installing \MP\ in a new
+operating environment. A list of various things that can't happen appears
+under ``this can't happen''.
+Approximately 25 sections are listed under ``inner loop''; these account
+for more than 60\pct! of \MP's running time, exclusive of input and output.
diff --git a/Build/source/texk/web2c/mplibdir/mpost.w b/Build/source/texk/web2c/mplibdir/mpost.w
new file mode 100644
index 00000000000..79ade1ead57
--- /dev/null
+++ b/Build/source/texk/web2c/mplibdir/mpost.w
@@ -0,0 +1,939 @@
+% $Id: mpost.w 892 2009-04-14 14:28:42Z taco $
+%
+% Copyright 2008 Taco Hoekwater.
+%
+% This program is free software: you can redistribute it and/or modify
+% it under the terms of the GNU Lesser General Public License as published by
+% the Free Software Foundation, either version 3 of the License, or
+% (at your option) any later version.
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+% GNU Lesser General Public License for more details.
+%
+% You should have received a copy of the GNU Lesser General Public License
+% along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+\font\tenlogo=logo10 % font used for the METAFONT logo
+\def\MP{{\tenlogo META}\-{\tenlogo POST}}
+
+\def\title{MetaPost executable}
+\def\[#1]{#1.}
+\pdfoutput=1
+
+@* \[1] Metapost executable.
+
+Now that all of \MP\ is a library, a separate program is needed to
+have our customary command-line interface.
+
+@ First, here are the C includes. |avl.h| is needed because of an
+|avl_allocator| that is defined in |mplib.h|
+
+@d true 1
+@d false 0
+
+@c
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#if defined (HAVE_SYS_TIME_H)
+#include <sys/time.h>
+#elif defined (HAVE_SYS_TIMEB_H)
+#include <sys/timeb.h>
+#endif
+#include <mplib.h>
+#include <mpxout.h>
+#ifdef WIN32
+#include <process.h>
+#endif
+#include <kpathsea/kpathsea.h>
+extern char *kpathsea_version_string;
+@= /*@@null@@*/ @> static char *mpost_tex_program = NULL;
+static int debug = 0; /* debugging for makempx */
+#ifdef WIN32
+#define GETCWD _getcwd
+#else
+#define GETCWD getcwd
+#endif
+static boolean recorder_enabled = false;
+static string recorder_name = NULL;
+static FILE *recorder_file = NULL;
+static char *job_name = NULL;
+static int dvitomp_only = 0;
+
+@ Allocating a bit of memory, with error detection:
+
+@d mpost_xfree(A) do { if (A!=NULL) free(A); A=NULL; } while (0)
+
+@c
+@= /*@@only@@*/ /*@@out@@*/ @> static void *mpost_xmalloc (size_t bytes) {
+ void *w = malloc (bytes);
+ if (w==NULL) {
+ fprintf(stderr,"Out of memory!\n");
+ exit(EXIT_FAILURE);
+ }
+ return w;
+}
+@= /*@@only@@*/ @> static char *mpost_xstrdup(const char *s) {
+ char *w;
+ w = strdup(s);
+ if (w==NULL) {
+ fprintf(stderr,"Out of memory!\n");
+ exit(EXIT_FAILURE);
+ }
+ return w;
+}
+static char *mpost_itoa (int i) {
+ char res[32] ;
+ unsigned idx = 30;
+ unsigned v = (unsigned)abs(i);
+ memset(res,0,32*sizeof(char));
+ while (v>=10) {
+ char d = (char)(v % 10);
+ v = v / 10;
+ res[idx--] = d;
+ }
+ res[idx--] = (char)v;
+ if (i<0) {
+ res[idx--] = '-';
+ }
+ return mpost_xstrdup(res+idx);
+}
+
+
+@ @c
+static void mpost_run_editor (MP mp, char *fname, int fline) {
+ char *temp, *command, *edit_value;
+ char c;
+ boolean sdone, ddone;
+ sdone = ddone = false;
+ edit_value = kpse_var_value ("MPEDIT");
+ if (edit_value == NULL)
+ edit_value = getenv("EDITOR");
+ if (edit_value == NULL) {
+ fprintf (stderr,"call_edit: can't find a suitable MPEDIT or EDITOR variable\n");
+ exit(mp_status(mp));
+ }
+ command = (string) mpost_xmalloc (strlen (edit_value) + strlen(fname) + 11 + 3);
+ temp = command;
+ while ((c = *edit_value++) != (char)0) {
+ if (c == '%') {
+ switch (c = *edit_value++) {
+ case 'd':
+ if (ddone) {
+ fprintf (stderr,"call_edit: `%%d' appears twice in editor command\n");
+ exit(EXIT_FAILURE);
+ } else {
+ char *s = mpost_itoa(fline);
+ if (s != NULL) {
+ while (*s != '\0')
+ *temp++ = *s++;
+ free(s);
+ }
+ ddone = true;
+ }
+ break;
+ case 's':
+ if (sdone) {
+ fprintf (stderr,"call_edit: `%%s' appears twice in editor command\n");
+ exit(EXIT_FAILURE);
+ } else {
+ while (*fname != '\0')
+ *temp++ = *fname++;
+ *temp++ = '.';
+ *temp++ = 'm';
+ *temp++ = 'p';
+ sdone = true;
+ }
+ break;
+ case '\0':
+ *temp++ = '%';
+ /* Back up to the null to force termination. */
+ edit_value--;
+ break;
+ default:
+ *temp++ = '%';
+ *temp++ = c;
+ break;
+ }
+ } else {
+ *temp++ = c;
+ }
+ }
+ *temp = '\0';
+ if (system (command) != 0)
+ fprintf (stderr, "! Trouble executing `%s'.\n", command);
+ exit(EXIT_FAILURE);
+}
+
+@
+@<Register the callback routines@>=
+options->run_editor = mpost_run_editor;
+
+@
+@c
+static string normalize_quotes (const char *name, const char *mesg) {
+ boolean quoted = false;
+ boolean must_quote = (strchr(name, ' ') != NULL);
+ /* Leave room for quotes and NUL. */
+ string ret = (string)mpost_xmalloc(strlen(name)+3);
+ string p;
+ const_string q;
+ p = ret;
+ if (must_quote)
+ *p++ = '"';
+ for (q = name; *q != '\0'; q++) {
+ if (*q == '"')
+ quoted = !quoted;
+ else
+ *p++ = *q;
+ }
+ if (must_quote)
+ *p++ = '"';
+ *p = '\0';
+ if (quoted) {
+ fprintf(stderr, "! Unbalanced quotes in %s %s\n", mesg, name);
+ exit(EXIT_FAILURE);
+ }
+ return ret;
+}
+
+@ Helpers for the filename recorder.
+
+@c
+void recorder_start(char *jobname) {
+ char cwd[1024];
+ recorder_name = (string)xmalloc((unsigned int)(strlen(jobname)+5));
+ strcpy(recorder_name, jobname);
+ strcat(recorder_name, ".fls");
+ recorder_file = xfopen(recorder_name, FOPEN_W_MODE);
+
+ if(GETCWD(cwd,1020) != NULL) {
+ fprintf(recorder_file, "PWD %s\n", cwd);
+ } else {
+ fprintf(recorder_file, "PWD <unknown>\n");
+ }
+}
+
+
+@ @c
+@= /*@@null@@*/ @> static char *makempx_find_file (MPX mpx, const char *nam,
+ const char *mode, int ftype) {
+ int fmt;
+ boolean req;
+ (void) mpx;
+ if (mode[0] != 'r') {
+ return strdup(nam);
+ }
+ req = true; fmt = -1;
+ switch(ftype) {
+ case mpx_tfm_format: fmt = kpse_tfm_format; break;
+ case mpx_vf_format: fmt = kpse_vf_format; req = false; break;
+ case mpx_trfontmap_format: fmt = kpse_mpsupport_format; break;
+ case mpx_trcharadj_format: fmt = kpse_mpsupport_format; break;
+ case mpx_desc_format: fmt = kpse_troff_font_format; break;
+ case mpx_fontdesc_format: fmt = kpse_troff_font_format; break;
+ case mpx_specchar_format: fmt = kpse_mpsupport_format; break;
+ }
+ if (fmt<0) return NULL;
+ return kpse_find_file (nam, fmt, req);
+}
+
+@ Invoke makempx (or troffmpx) to make sure there is an up-to-date
+ .mpx file for a given .mp file. (Original from John Hobby 3/14/90)
+
+@d default_args " --parse-first-line --interaction=nonstopmode"
+@d TEX "tex"
+@d TROFF "soelim | eqn -Tps -d$$ | troff -Tps"
+
+@c
+#ifndef MPXCOMMAND
+#define MPXCOMMAND "makempx"
+#endif
+static int mpost_run_make_mpx (MP mp, char *mpname, char *mpxname) {
+ int ret;
+ char *cnf_cmd = kpse_var_value ("MPXCOMMAND");
+
+ if (cnf_cmd != NULL && (strcmp (cnf_cmd, "0")==0)) {
+ /* If they turned off this feature, just return success. */
+ ret = 0;
+
+ } else {
+ /* We will invoke something. Compile-time default if nothing else. */
+ char *cmd;
+ char *tmp = normalize_quotes(mpname, "mpname");
+ char *qmpname = kpse_find_file (tmp,kpse_mp_format, true);
+ char *qmpxname = normalize_quotes(mpxname, "mpxname");
+ mpost_xfree(tmp);
+ if (cnf_cmd!=NULL && (strcmp (cnf_cmd, "1")!=0)) {
+ if (mp_troff_mode(mp)!=0)
+ cmd = concatn (cnf_cmd, " -troff ",
+ qmpname, " ", qmpxname, NULL);
+ else if (mpost_tex_program!=NULL && *mpost_tex_program != '\0')
+ cmd = concatn (cnf_cmd, " -tex=", mpost_tex_program, " ",
+ qmpname, " ", qmpxname, NULL);
+ else
+ cmd = concatn (cnf_cmd, " -tex ", qmpname, " ", qmpxname, NULL);
+
+ /* Run it. */
+ ret = system (cmd);
+ free (cmd);
+ mpost_xfree(qmpname);
+ mpost_xfree(qmpxname);
+ } else {
+ mpx_options * mpxopt;
+ char *s = NULL;
+ char *maincmd = NULL;
+ int mpxmode = mp_troff_mode(mp);
+ char *mpversion = mp_metapost_version () ;
+ mpxopt = mpost_xmalloc(sizeof(mpx_options));
+ if (mpost_tex_program != NULL && *mpost_tex_program != '\0') {
+ maincmd = mpost_xstrdup(mpost_tex_program);
+ } else {
+ if (mpxmode == mpx_tex_mode) {
+ s = kpse_var_value("TEX");
+ if (s==NULL) s = kpse_var_value("MPXMAINCMD");
+ if (s==NULL) s = mpost_xstrdup (TEX);
+ maincmd = (char *)mpost_xmalloc (strlen(s)+strlen(default_args)+1);
+ strcpy(maincmd,s);
+ strcat(maincmd,default_args);
+ free(s);
+ } else {
+ s = kpse_var_value("TROFF");
+ if (s==NULL) s = kpse_var_value("MPXMAINCMD");
+ if (s==NULL) s = mpost_xstrdup (TROFF);
+ maincmd = s;
+ }
+ }
+ mpxopt->mode = mpxmode;
+ mpxopt->cmd = maincmd;
+ mpxopt->mptexpre = kpse_var_value("MPTEXPRE");
+ mpxopt->debug = debug;
+ mpxopt->mpname = qmpname;
+ mpxopt->mpxname = qmpxname;
+ mpxopt->find_file = makempx_find_file;
+ {
+ char *banner = "% Written by metapost version ";
+ mpxopt->banner = mpost_xmalloc(strlen(mpversion)+strlen(banner)+1);
+ strcpy (mpxopt->banner, banner);
+ strcat (mpxopt->banner, mpversion);
+ }
+ ret = mpx_makempx(mpxopt);
+ mpost_xfree(mpxopt->cmd);
+ mpost_xfree(mpxopt->mptexpre);
+ mpost_xfree(mpxopt->banner);
+ mpost_xfree(mpxopt->mpname);
+ mpost_xfree(mpxopt->mpxname);
+ mpost_xfree(mpxopt);
+ mpost_xfree(mpversion);
+ }
+ }
+
+ mpost_xfree (cnf_cmd);
+ return (int)(ret == 0);
+}
+
+static int mpost_run_dvitomp (char *dviname, char *mpxname) {
+ int i, ret;
+ char *m, *d;
+ mpx_options * mpxopt;
+ char *mpversion = mp_metapost_version () ;
+ mpxopt = mpost_xmalloc(sizeof(mpx_options));
+ memset(mpxopt,0,sizeof(mpx_options));
+ mpxopt->mode = mpx_tex_mode;
+ if (dviname == NULL)
+ return EXIT_FAILURE;
+ i = strlen(dviname);
+ if (mpxname==NULL) {
+ m = mpost_xstrdup(dviname);
+ if (i>4 && *(m+i-4)=='.'
+ && *(m+i-3)=='d' && *(m+i-2)=='v' && *(m+i-1)=='i')
+ *(m+i-4)='\0' ;
+ } else {
+ m = mpost_xstrdup(mpxname);
+ }
+ d = mpost_xstrdup(dviname);
+ if (!(i>4 && *(d+i-4)=='.'
+ && *(d+i-3)=='d' && *(d+i-2)=='v' && *(d+i-1)=='i')) {
+ char *s = malloc (i+5);
+ memset(s,0,i+5);
+ s = strcat(s, d);
+ (void)strcat(s+i-1, ".dvi");
+ mpost_xfree (d);
+ d = s ;
+ }
+
+ i = strlen(m);
+ if (i>4 && *(m+i-4)=='.'
+ && *(m+i-3)=='m' && *(m+i-2)=='p' && *(m+i-1)=='x') {
+ } else {
+ char *s = malloc (i+5);
+ memset(s,0,i+5);
+ s = strcat(s, m);
+ (void)strcat(s+i-1, ".mpx");
+ mpost_xfree (m);
+ m = s ;
+ }
+ mpxopt->mpname = d;
+ mpxopt->mpxname = m;
+
+ mpxopt->find_file = makempx_find_file;
+ {
+ char *banner = "% Written by dvitomp version ";
+ mpxopt->banner = mpost_xmalloc(strlen(mpversion)+strlen(banner)+1);
+ strcpy (mpxopt->banner, banner);
+ strcat (mpxopt->banner, mpversion);
+ }
+ ret = mpx_run_dvitomp(mpxopt);
+ mpost_xfree(mpxopt->banner);
+ mpost_xfree(mpxopt);
+ mpost_xfree(mpversion);
+ return ret;
+}
+
+
+@
+@<Register the callback routines@>=
+if (!nokpse)
+ options->run_make_mpx = mpost_run_make_mpx;
+
+
+@ @c
+static int get_random_seed (void) {
+ int ret = 0;
+#if defined (HAVE_GETTIMEOFDAY)
+ struct timeval tv;
+ gettimeofday(&tv, NULL);
+ ret = (tv.tv_usec + 1000000 * tv.tv_usec);
+#elif defined (HAVE_FTIME)
+ struct timeb tb;
+ ftime(&tb);
+ ret = (tb.millitm + 1000 * tb.time);
+#else
+ time_t clock = time ((time_t*)NULL);
+ struct tm *tmptr = localtime(&clock);
+ if (tmptr!=NULL)
+ ret = (tmptr->tm_sec + 60*(tmptr->tm_min + 60*tmptr->tm_hour));
+#endif
+ return ret;
+}
+
+@ @<Register the callback routines@>=
+options->random_seed = get_random_seed();
+
+@ @c
+static char *mpost_find_file(MP mp, const char *fname, const char *fmode, int ftype) {
+ size_t l ;
+ char *s;
+ (void)mp;
+ s = NULL;
+ if (fmode[0]=='r') {
+ if (ftype>=mp_filetype_text) {
+ s = kpse_find_file (fname, kpse_mp_format, 0);
+ } else {
+ switch(ftype) {
+ case mp_filetype_program:
+ l = strlen(fname);
+ if (l>3 && strcmp(fname+l-3,".mf")==0) {
+ s = kpse_find_file (fname, kpse_mf_format, 0);
+ } else {
+ s = kpse_find_file (fname, kpse_mp_format, 0);
+ }
+ break;
+ case mp_filetype_memfile:
+ s = kpse_find_file (fname, kpse_mem_format, 1);
+ break;
+ case mp_filetype_metrics:
+ s = kpse_find_file (fname, kpse_tfm_format, 0);
+ break;
+ case mp_filetype_fontmap:
+ s = kpse_find_file (fname, kpse_fontmap_format, 0);
+ break;
+ case mp_filetype_font:
+ s = kpse_find_file (fname, kpse_type1_format, 0);
+ break;
+ case mp_filetype_encoding:
+ s = kpse_find_file (fname, kpse_enc_format, 0);
+ break;
+ }
+ }
+ } else {
+ if (fname!=NULL)
+ s = mpost_xstrdup(fname); /* when writing */
+ }
+ return s;
+}
+
+@ @<Register the callback routines@>=
+if (!nokpse)
+ options->find_file = mpost_find_file;
+
+@ @c
+static void *mpost_open_file(MP mp, const char *fname, const char *fmode, int ftype) {
+ char realmode[3];
+ char *s;
+ if (ftype==mp_filetype_terminal) {
+ return (fmode[0] == 'r' ? stdin : stdout);
+ } else if (ftype==mp_filetype_error) {
+ return stderr;
+ } else {
+ s = mpost_find_file (mp, fname, fmode, ftype);
+ if (s!=NULL) {
+ void *ret = NULL;
+ realmode[0] = *fmode;
+ realmode[1] = 'b';
+ realmode[2] = '\0';
+ ret = (void *)fopen(s,realmode);
+ if (recorder_enabled) {
+ if (!recorder_file)
+ recorder_start(job_name);
+ if (*fmode == 'r')
+ fprintf(recorder_file, "INPUT %s\n", s);
+ else
+ fprintf(recorder_file, "OUTPUT %s\n", s);
+ }
+ free(s);
+ return ret;
+ }
+ }
+ return NULL;
+}
+
+@ @<Register the callback routines@>=
+if (!nokpse)
+ options->open_file = mpost_open_file;
+
+
+@ At the moment, the command line is very simple.
+
+@d option_is(A) ((strncmp(argv[a],"--" A, strlen(A)+2)==0) ||
+ (strncmp(argv[a],"-" A, strlen(A)+1)==0))
+@d option_arg(B) (mpost_optarg != NULL && strncmp(mpost_optarg,B, strlen(B))==0)
+
+
+@<Read and set command line options@>=
+{
+ char *mpost_optarg;
+ boolean ini_version_test = false;
+ while (++a<argc) {
+ mpost_optarg = strstr(argv[a],"=") ;
+ if (mpost_optarg!=NULL) {
+ mpost_optarg++;
+ if (*mpost_optarg == '\0') mpost_optarg=NULL;
+ }
+ if (option_is("ini")) {
+ ini_version_test = true;
+ } else if (option_is("debug")) {
+ debug = 1;
+ } else if (option_is ("kpathsea-debug")) {
+ if (mpost_optarg!=NULL)
+ kpathsea_debug |= atoi (mpost_optarg);
+ } else if (option_is("mem")) {
+ if (mpost_optarg!=NULL) {
+ mpost_xfree(options->mem_name);
+ options->mem_name = mpost_xstrdup(mpost_optarg);
+ if (user_progname == NULL)
+ user_progname = mpost_optarg;
+ }
+ } else if (option_is("jobname")) {
+ if (mpost_optarg!=NULL) {
+ mpost_xfree(options->job_name);
+ options->job_name = mpost_xstrdup(mpost_optarg);
+ }
+ } else if (option_is ("progname")) {
+ user_progname = mpost_optarg;
+ } else if (option_is("troff") || option_is("T")) {
+ options->troff_mode = (int)true;
+ } else if (option_is("recorder")) {
+ recorder_enabled = true;
+ } else if (option_is ("tex")) {
+ mpost_tex_program = mpost_optarg;
+ } else if (option_is("interaction")) {
+ if (option_arg("batchmode")) {
+ options->interaction = mp_batch_mode;
+ } else if (option_arg("nonstopmode")) {
+ options->interaction = mp_nonstop_mode;
+ } else if (option_arg("scrollmode")) {
+ options->interaction = mp_scroll_mode;
+ } else if (option_arg("errorstopmode")) {
+ options->interaction = mp_error_stop_mode;
+ } else {
+ fprintf(stdout,"warning: %s: unknown option argument %s\n", argv[0], argv[a]);
+ }
+ } else if (option_is("no-kpathsea")) {
+ nokpse=true;
+ } else if (option_is("file-line-error")) {
+ options->file_line_error_style=true;
+ } else if (option_is("no-file-line-error")) {
+ options->file_line_error_style=false;
+ } else if (option_is("dvitomp")) {
+ dvitomp_only = 1;
+ } else if (option_is("help")) {
+ @<Show help and exit@>;
+ } else if (option_is("version")) {
+ @<Show version and exit@>;
+ } else if (option_is("8bit") ||
+ option_is("parse-first-line")) {
+ /* do nothing, these are always on */
+ } else if (option_is("halt-on-error")) {
+ options->halt_on_error = true;
+ } else if (option_is("translate-file") ||
+ option_is("output-directory") ||
+ option_is("no-parse-first-line")) {
+ fprintf(stdout,"warning: %s: unimplemented option %s\n", argv[0], argv[a]);
+ } else if (option_is("")) {
+ fprintf(stdout,"fatal error: %s: unknown option %s\n", argv[0], argv[a]);
+ exit(EXIT_FAILURE);
+ } else {
+ break;
+ }
+ }
+ options->ini_version = (int)ini_version_test;
+}
+
+@
+@<Show help...@>=
+{
+fprintf(stdout,
+"\n"
+"Usage: mpost [OPTION] [&MEMNAME] [MPNAME[.mp]] [COMMANDS]\n"
+" mpost --dvitomp DVINAME[.dvi] [MPXNAME[.mpx]]\n"
+"\n"
+" Run MetaPost on MPNAME, usually creating MPNAME.NNN (and perhaps\n"
+" MPNAME.tfm), where NNN are the character numbers generated.\n"
+" Any remaining COMMANDS are processed as MetaPost input,\n"
+" after MPNAME is read.\n\n"
+" With a --dvitomp argument, MetaPost acts as DVI-to-MPX converter only.\n\n");
+fprintf(stdout,
+" -ini be inimpost, for dumping mem files\n"
+" -interaction=STRING set interaction mode (STRING=batchmode/nonstopmode/\n"
+" scrollmode/errorstopmode)\n"
+" -jobname=STRING set the job name to STRING\n"
+" -progname=STRING set program (and mem) name to STRING\n"
+" -tex=TEXPROGRAM use TEXPROGRAM for text labels\n"
+" [-no]-file-line-error disable/enable file:line:error style messages\n"
+);
+fprintf(stdout,
+" -kpathsea-debug=NUMBER set path searching debugging flags according to\n"
+" the bits of NUMBER\n"
+" -mem=MEMNAME or &MEMNAME use MEMNAME instead of program name or a %%& line\n"
+" -recorder enable filename recorder\n"
+" -troff set prologues:=1 and assume TEXPROGRAM is really troff\n"
+" -help display this help and exit\n"
+" -version output version information and exit\n"
+"\n"
+"Email bug reports to mp-implementors@@tug.org.\n"
+"\n");
+ exit(EXIT_SUCCESS);
+}
+
+@
+@<Show version...@>=
+{
+ char *s = mp_metapost_version();
+fprintf(stdout,
+"\n"
+"MetaPost %s\n"
+"Copyright 2008 AT&T Bell Laboratories.\n"
+"There is NO warranty. Redistribution of this software is\n"
+"covered by the terms of both the MetaPost copyright and\n"
+"the Lesser GNU Lesser General Public License.\n"
+"For more information about these matters, see the files\n"
+"named COPYING, COPYING.LESSER and the MetaPost source.\n"
+"Primary author of MetaPost: John Hobby.\n"
+"Current maintainer of MetaPost: Taco Hoekwater.\n"
+"\n", s);
+ mpost_xfree(s);
+ exit(EXIT_SUCCESS);
+}
+
+@ The final part of the command line, after option processing, is
+stored in the \MP\ instance, this will be taken as the first line of
+input.
+
+@d command_line_size 256
+
+@<Copy the rest of the command line@>=
+{
+ mpost_xfree(options->command_line);
+ options->command_line = mpost_xmalloc(command_line_size);
+ strcpy(options->command_line,"");
+ if (a<argc) {
+ k=0;
+ for(;a<argc;a++) {
+ char *c = argv[a];
+ while (*c != '\0') {
+ if (k<(command_line_size-1)) {
+ options->command_line[k++] = *c;
+ }
+ c++;
+ }
+ options->command_line[k++] = ' ';
+ }
+ while (k>0) {
+ if (options->command_line[(k-1)] == ' ')
+ k--;
+ else
+ break;
+ }
+ options->command_line[k] = '\0';
+ }
+}
+
+@ A simple function to get numerical |texmf.cnf| values
+@c
+static int setup_var (int def, const char *var_name, boolean nokpse) {
+ if (!nokpse) {
+ char * expansion = kpse_var_value (var_name);
+ if (expansion) {
+ int conf_val = atoi (expansion);
+ free (expansion);
+ if (conf_val > 0) {
+ return conf_val;
+ }
+ }
+ }
+ return def;
+}
+
+@ @<Set up the banner line@>=
+{
+ char * mpversion = mp_metapost_version () ;
+ const char * banner = "This is MetaPost, version ";
+ const char * kpsebanner_start = " (";
+ const char * kpsebanner_stop = ")";
+ mpost_xfree(options->banner);
+ options->banner = mpost_xmalloc(strlen(banner)+
+ strlen(mpversion)+
+ strlen(kpsebanner_start)+
+ strlen(kpathsea_version_string)+
+ strlen(kpsebanner_stop)+1);
+ strcpy (options->banner, banner);
+ strcat (options->banner, mpversion);
+ strcat (options->banner, kpsebanner_start);
+ strcat (options->banner, kpathsea_version_string);
+ strcat (options->banner, kpsebanner_stop);
+ mpost_xfree(mpversion);
+}
+
+@ Precedence order is:
+
+\item {} \.{-mem=MEMNAME} on the command line
+\item {} \.{\&MEMNAME} on the command line
+\item {} \.{\%\&MEM} as first line inside input file
+\item {} \.{argv[0]} if all else fails
+
+@<Discover the mem name@>=
+{
+ char *m = NULL; /* head of potential |mem_name| */
+ char *n = NULL; /* a moving pointer */
+ if (options->command_line != NULL && *(options->command_line) == '&'){
+ m = mpost_xstrdup(options->command_line+1);
+ n = m;
+ while (*n != '\0' && *n != ' ') n++;
+ while (*n == ' ') n++;
+ if (*n != '\0') { /* more command line to follow */
+ char *s = mpost_xstrdup(n);
+ if (n>m) n--;
+ while (*n == ' ' && n>m) n--;
+ n++;
+ *n ='\0'; /* this terminates |m| */
+ mpost_xfree(options->command_line);
+ options->command_line = s;
+ } else { /* only \.{\&MEMNAME} on command line */
+ if (n>m) n--;
+ while (*n == ' ' && n>m) n--;
+ n++;
+ *n ='\0'; /* this terminates |m| */
+ mpost_xfree(options->command_line);
+ }
+ if ( options->mem_name == NULL && *m != '\0') {
+ mpost_xfree(options->mem_name); /* for lint only */
+ options->mem_name = m;
+ } else {
+ mpost_xfree(m);
+ }
+ }
+}
+if ( options->mem_name == NULL ) {
+ char *m = NULL; /* head of potential |job_name| */
+ char *n = NULL; /* a moving pointer */
+ if (options->command_line != NULL && *(options->command_line) != '\\'){
+ m = mpost_xstrdup(options->command_line);
+ n = m;
+ while (*n != '\0' && *n != ' ') n++;
+ if (n>m) {
+ char *fname;
+ *n='\0';
+ fname = m;
+ if (!nokpse)
+ fname = kpse_find_file(m,kpse_mp_format,true);
+ if (fname == NULL) {
+ mpost_xfree(m);
+ } else {
+ FILE *F = fopen(fname,"r");
+ if (F==NULL) {
+ mpost_xfree(fname);
+ } else {
+ char *line = mpost_xmalloc(256);
+ if (fgets(line,255,F) == NULL) {
+ (void)fclose(F);
+ mpost_xfree(fname);
+ mpost_xfree(line);
+ } else {
+ (void)fclose(F);
+ while (*line != '\0' && *line == ' ') line++;
+ if (*line == '%') {
+ n = m = line+1;
+ while (*n != '\0' && *n == ' ') n++;
+ if (*n == '&') {
+ m = n+1;
+ while (*n != '\0' && *n != ' ') n++;
+ if (n>(m+1)) {
+ n--;
+ while (*n == ' ' && n>m) n--;
+ *n ='\0'; /* this terminates |m| */
+ options->mem_name = mpost_xstrdup(m);
+ mpost_xfree(fname);
+ } else {
+ mpost_xfree(fname);
+ mpost_xfree(line);
+ }
+ }
+ }
+ }
+ }
+ }
+ } else {
+ mpost_xfree(m);
+ }
+ }
+}
+if ( options->mem_name == NULL )
+ if (kpse_program_name!=NULL)
+ options->mem_name = mpost_xstrdup(kpse_program_name);
+
+
+@ The jobname needs to be known for the recorder to work.
+
+@<Discover the job name@>=
+if ( options->job_name == NULL ) {
+ char *m = NULL; /* head of potential |job_name| */
+ char *n = NULL; /* a moving pointer */
+ if (options->command_line != NULL){
+ m = mpost_xstrdup(options->command_line);
+ n = m;
+ if (*(options->command_line) != '\\') { /* this is the simple case */
+ while (*n != '\0' && *n != ' ') n++;
+ if (n>m) {
+ *n='\0';
+ job_name = mpost_xstrdup(m);
+ }
+ } else { /* this is still not perfect, but better */
+ char *mm = strstr(m,"input ");
+ if (mm != NULL) {
+ mm += 6;
+ n = mm;
+ while (*n != '\0' && *n != ' ' && *n!=';') n++;
+ if (n>mm) {
+ *n='\0';
+ job_name = mpost_xstrdup(mm);
+ }
+ }
+ }
+ free(m);
+ }
+ if (job_name == NULL) {
+ if (options->ini_version == 1 &&
+ options->mem_name != NULL) {
+ job_name = mpost_xstrdup(options->mem_name);
+ }
+ }
+ if (job_name == NULL) {
+ job_name = mpost_xstrdup("mpout");
+ } else {
+ size_t i = strlen(job_name);
+ if (i>3
+ && *(job_name+i-3)=='.'
+ && *(job_name+i-2)=='m'
+ && *(job_name+i-1)=='p')
+ *(job_name+i-3)='\0';
+ }
+ options->job_name = job_name;
+} else {
+ job_name = mpost_xstrdup(options->job_name);
+}
+
+
+@ Now this is really it: \MP\ starts and ends here.
+
+@c
+int main (int argc, char **argv) { /* |start_here| */
+ int k; /* index into buffer */
+ int history; /* the exit status */
+ MP mp; /* a metapost instance */
+ struct MP_options * options; /* instance options */
+ int a=0; /* argc counter */
+ boolean nokpse = false; /* switch to {\it not} enable kpse */
+ char *user_progname = NULL; /* If the user overrides argv[0] with -progname. */
+ options = mp_options();
+ options->ini_version = (int)false;
+ options->print_found_names = (int)true;
+ @<Read and set command line options@>;
+ if (dvitomp_only) {
+ char *mpx = NULL, *dvi = NULL;
+ if (a==argc) {
+ /* error ? */
+ } else {
+ dvi = argv[a++];
+ if (a<argc) {
+ mpx = argv[a++];
+ }
+ }
+ if (!nokpse)
+ kpse_set_program_name("dvitomp", user_progname);
+ exit (mpost_run_dvitomp(dvi, mpx));
+ }
+
+ @= /*@@-nullpass@@*/ @>
+ if (!nokpse) {
+ kpse_set_program_enabled (kpse_mem_format, MAKE_TEX_FMT_BY_DEFAULT,
+ kpse_src_compile);
+ kpse_set_program_name("mpost", user_progname);
+ }
+ @= /*@@=nullpass@@*/ @>
+ if(putenv((char *)"engine=metapost"))
+ fprintf(stdout,"warning: could not set up $engine\n");
+ options->main_memory = setup_var (50000,"main_memory",nokpse);
+ options->hash_size = (unsigned)setup_var (16384,"hash_size",nokpse);
+ options->max_in_open = setup_var (25,"max_in_open",nokpse);
+ options->param_size = setup_var (1500,"param_size",nokpse);
+ options->error_line = setup_var (79,"error_line",nokpse);
+ options->half_error_line = setup_var (50,"half_error_line",nokpse);
+ options->max_print_line = setup_var (100,"max_print_line",nokpse);
+ @<Set up the banner line@>;
+ @<Copy the rest of the command line@>;
+ if (options->ini_version!=(int)true) {
+ @<Discover the mem name@>;
+ }
+ @<Discover the job name@>;
+ @<Register the callback routines@>;
+ mp = mp_initialize(options);
+ mpost_xfree(options->command_line);
+ mpost_xfree(options->mem_name);
+ mpost_xfree(options->job_name);
+ mpost_xfree(options->banner);
+ free(options);
+ if (mp==NULL)
+ exit(EXIT_FAILURE);
+ history = mp_status(mp);
+ if (history!=0)
+ exit(history);
+ history = mp_run(mp);
+ (void)mp_finish(mp);
+ exit(history);
+}
+
diff --git a/Build/source/texk/web2c/mplibdir/mpxout.w b/Build/source/texk/web2c/mplibdir/mpxout.w
new file mode 100644
index 00000000000..283f1c9c41c
--- /dev/null
+++ b/Build/source/texk/web2c/mplibdir/mpxout.w
@@ -0,0 +1,4312 @@
+% $Id: mpxout.w 892 2009-04-14 14:28:42Z taco $
+%
+% Copyright 2008 Taco Hoekwater.
+%
+% This program is free software: you can redistribute it and/or modify
+% it under the terms of the GNU Lesser General Public License as published by
+% the Free Software Foundation, either version 3 of the License, or
+% (at your option) any later version.
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+% GNU Lesser General Public License for more details.
+%
+% You should have received a copy of the GNU Lesser General Public License
+% along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+\def\title{Creating mpx files}
+\def\hang{\hangindent 3em\indent\ignorespaces}
+\def\MP{MetaPost}
+\def\LaTeX{{\rm L\kern-.36em\raise.3ex\hbox{\sc a}\kern-.15em
+ T\kern-.1667em\lower.7ex\hbox{E}\kern-.125emX}}
+
+\def\(#1){} % this is used to make section names sort themselves better
+\def\9#1{} % this is used for sort keys in the index
+\def\[#1]{#1.}
+
+\pdfoutput=1
+
+@* \[1] Makempx overview.
+
+This source file implements the makempx functionality for the new \MP.
+It includes all of the functional code from the old standalone programs
+
+\item{}mpto
+\item{}dmp
+\item{}dvitomp
+\item{}makempx
+
+combined into one, with many changes to make all of the code cooperate
+nicely.
+
+@ Header files
+
+The local C preprocessor definitions have to come after the C includes
+in order to prevent name clashes.
+
+@c
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <assert.h>
+#include <setjmp.h>
+#include <errno.h> /* TODO autoconf ? */
+/* unistd.h is needed for every non-Win32 platform, and we assume
+ * that implies that sys/types.h is also present
+ */
+#ifndef WIN32
+#include <sys/types.h>
+#include <unistd.h>
+#endif
+/* processes */
+#ifdef WIN32
+#include <io.h>
+#include <process.h>
+#else
+#if HAVE_SYS_WAIT_H
+# include <sys/wait.h>
+#endif
+#ifndef WEXITSTATUS
+# define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
+#endif
+#ifndef WIFEXITED
+# define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
+#endif
+#endif
+/* directories */
+#ifdef WIN32
+#include <direct.h>
+#else
+#if HAVE_DIRENT_H
+# include <dirent.h>
+#else
+# define dirent direct
+# if HAVE_SYS_NDIR_H
+# include <sys/ndir.h>
+# endif
+# if HAVE_SYS_DIR_H
+# include <sys/dir.h>
+# endif
+# if HAVE_NDIR_H
+# include <ndir.h>
+# endif
+#endif
+#endif
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#include <ctype.h>
+#include <time.h>
+#include <math.h>
+#define trunc(x) ((integer) (x))
+#define fabs(x) ((x)<0?(-(x)):(x))
+#define floor(x) ((integer) (fabs(x)))
+#ifndef PI
+#define PI 3.14159265358979323846
+#endif
+#include "avl.h"
+extern void *avl_probe (avl_tree t, void *p);
+#include "mpxout.h"
+@h
+
+@ Data types
+
+From the Pascal code of DVItoMP two implicit types are inherited: |web_boolean| and
+|web_integer|.
+
+The more complex datatypes are defined in the following sections.
+
+@d true 1
+@d false 0
+
+@c
+typedef signed int web_integer;
+typedef signed int web_boolean;
+@<C Data Types@>
+@<Declarations@>
+
+@ The single most important data structure is the structure
+|mpx_data|. It contains all of the global state for a specific
+|makempx| run. A pointer to it is passed as the first argument to just
+about every function call.
+
+One of the fields is a bit special because it is so important: |mode|
+is the decider between running \TeX\ or Troff as the typesetting
+engine.
+
+@(mpxout.h@>=
+typedef enum {
+ mpx_tex_mode=0,
+ mpx_troff_mode=1
+} mpx_modes;
+typedef struct mpx_data * MPX;
+
+@ @<C Data Types@>=
+@<Types in the outer block@>
+typedef struct mpx_data {
+ int mode;
+ @<Globals@>
+} mpx_data ;
+
+@ Here are some macros for common programming idioms.
+
+@d MAXINT 0x7FFFFF /* somewhat arbitrary */
+
+@d incr(A) (A)=(A)+1 /* increase a variable by unity */
+@d decr(A) (A)=(A)-1 /* decrease a variable by unity */
+
+@ Once an MPX object is allocated, the memory it occupies needs to be
+initialized to a usable state. This procedure gets things started
+properly.
+
+This function is not allowed to run |mpx_abort| because at this
+point the jump buffer is not yet initialized, so it should only
+be used for things that cannot go wrong!
+
+@c
+static void mpx_initialize (MPX mpx) {
+ memset(mpx,0,sizeof(struct mpx_data));
+ @<Set initial values@>@/
+}
+
+@ A global variable |history| keeps track of what type of errors have
+occurred with the hope that that \MP\ can be warned of any problems.
+
+@<Types...@>=
+enum mpx_history_states {
+ mpx_spotless=0, /* |history| value when no problems have been found */
+ mpx_cksum_trouble, /* |history| value there have been font checksum mismatches */
+ mpx_warning_given, /* |history| value after a recoverable error */
+ mpx_fatal_error /* |history| value if processing had to be aborted */
+};
+
+
+@ @<Glob...@>=
+int history;
+
+@ @<Set init...@>=
+mpx->history=mpx_spotless;
+
+@ The structure has room for the names and the |FILE *| for the
+input and output files. The most important ones are listed here,
+the variables for the intermediate files are declared where they
+are needed.
+
+@<Globals@>=
+char *banner;
+char *mpname;
+FILE *mpfile;
+char *mpxname;
+FILE *mpxfile;
+FILE *errfile;
+int lnno ; /* current line number */
+
+@ A set of basic reporting functions.
+
+@c
+static void mpx_printf(MPX mpx, char *header, char *msg, va_list ap) {
+ fprintf(mpx->errfile, "makempx %s: %s:", header, mpx->mpname);
+ if (mpx->lnno!=0)
+ fprintf(mpx->errfile, "%d:", mpx->lnno);
+ fprintf(mpx->errfile, " ");
+ (void)vfprintf(mpx->errfile, msg, ap);
+ fprintf(mpx->errfile, "\n");
+}
+
+@ @c
+static void mpx_report(MPX mpx, char *msg, ...) {
+ va_list ap;
+ if (mpx->debug==0) return;
+ va_start(ap, msg);
+ mpx_printf(mpx, "debug", msg, ap);
+ va_end(ap);
+ if ( mpx->history < mpx_warning_given )
+ mpx->history=mpx_cksum_trouble;
+}
+
+@ @c
+static void mpx_warn(MPX mpx, char *msg, ...) {
+ va_list ap;
+ va_start(ap, msg);
+ mpx_printf(mpx, "warning", msg, ap);
+ va_end(ap);
+ if ( mpx->history < mpx_warning_given )
+ mpx->history=mpx_cksum_trouble;
+}
+
+@ @c
+static void mpx_error(MPX mpx, char *msg, ...) {
+ va_list ap;
+ va_start(ap, msg);
+ mpx_printf(mpx, "error", msg, ap);
+ va_end(ap);
+ mpx->history=mpx_warning_given;
+}
+
+@ The program uses a |jump_buf| to handle non-local returns,
+this is initialized at a single spot: the start of |mp_makempx|.
+
+@d mpx_jump_out longjmp(mpx->jump_buf,1)
+
+@<Glob...@>=
+jmp_buf jump_buf;
+
+@
+@c
+static void mpx_abort(MPX mpx, char *msg, ...) {
+ va_list ap;
+ va_start(ap, msg);
+ mpx_printf(mpx, "fatal", msg, ap);
+ va_end(ap);
+ mpx->history=mpx_fatal_error;
+ mpx_erasetmp(mpx);
+ mpx_jump_out;
+}
+
+@ @<Install and test the non-local jump buffer@>=
+if (setjmp(mpx->jump_buf) != 0) {
+ int h = mpx->history;
+ xfree(mpx->buf);
+ xfree(mpx->maincmd);
+ xfree(mpx->mpname);
+ xfree(mpx->mpxname);
+ xfree(mpx);
+ return h;
+}
+
+@ @c
+static FILE *mpx_xfopen (MPX mpx, char *fname, char *fmode) {
+ FILE *f = fopen(fname,fmode);
+ if (f == NULL)
+ mpx_abort(mpx,"File open error for %s in mode %s", fname, fmode);
+ return f;
+}
+static void mpx_fclose (MPX mpx, FILE *file) {
+ (void)mpx;
+ (void)fclose(file);
+}
+
+@
+@d xfree(A) do { mpx_xfree(A); A=NULL; } while (0)
+@d xrealloc(P,A,B) mpx_xrealloc(mpx,P,A,B)
+@d xmalloc(A,B) mpx_xmalloc(mpx,A,B)
+@d xstrdup(A) mpx_xstrdup(mpx,A)
+
+@<Declarations@>=
+static void mpx_xfree (void *x);
+static void *mpx_xrealloc (MPX mpx, void *p, size_t nmem, size_t size) ;
+static void *mpx_xmalloc (MPX mpx, size_t nmem, size_t size) ;
+static char *mpx_xstrdup(MPX mpX, const char *s);
+
+
+@ The |max_size_test| guards against overflow, on the assumption that
+|size_t| is at least 31bits wide.
+
+@d max_size_test 0x7FFFFFFF
+
+@c
+static void mpx_xfree (void *x) {
+ if (x!=NULL) free(x);
+}
+static void *mpx_xrealloc (MPX mpx, void *p, size_t nmem, size_t size) {
+ void *w ;
+ if ((max_size_test/size)<nmem) {
+ mpx_abort(mpx,"Memory size overflow");
+ }
+ w = realloc (p,(nmem*size));
+ if (w==NULL) mpx_abort(mpx,"Out of Memory");
+ return w;
+}
+static void *mpx_xmalloc (MPX mpx, size_t nmem, size_t size) {
+ void *w;
+ if ((max_size_test/size)<nmem) {
+ mpx_abort(mpx,"Memory size overflow");
+ }
+ w = malloc (nmem*size);
+ if (w==NULL) mpx_abort(mpx,"Out of Memory");
+ return w;
+}
+static char *mpx_xstrdup(MPX mpx, const char *s) {
+ char *w;
+ if (s==NULL)
+ return NULL;
+ w = strdup(s);
+ if (w==NULL) mpx_abort(mpx,"Out of Memory");
+ return w;
+}
+@* The command 'newer' became a function.
+
+We may have high-res timers in struct stat. If we do, use them.
+
+@c
+static int mpx_newer(char *source, char *target) {
+ struct stat source_stat, target_stat;
+#if HAVE_SYS_STAT_H
+ if (stat(target, &target_stat) < 0) return 0; /* true */
+ if (stat(source, &source_stat) < 0) return 1; /* false */
+#if HAVE_ST_MTIM
+ if (source_stat.st_mtim.tv_sec > target_stat.st_mtim.tv_sec ||
+ (source_stat.st_mtim.tv_sec == target_stat.st_mtim.tv_sec &&
+ source_stat.st_mtim.tv_nsec >+ target_stat.st_mtim.tv_nsec))
+ return 0;
+#else
+ if (source_stat.st_mtime >= target_stat.st_mtime)
+ return 0;
+#endif
+#endif
+ return 1;
+}
+
+
+
+@* Extracting data from \MP\ input.
+
+This part of the program transforms a \MP\ input file into a \TeX\ or
+troff input file by stripping out \.{btex}$\ldots$\.{etex} and
+\.{verbatimtex}$\ldots$\.{etex} sections.
+Leading and trailing spaces and tabs are removed from the
+extracted material and it is surrounded by the preceding and following
+strings defined immediately below. The input file should be given as
+argument 1 and the resulting \TeX\ or troff file is written on standard
+output.
+
+John Hobby wrote the original version, which has since been
+extensively altered. The current implementation is a bit trickier
+than I would like, but changing it will take careful study and
+will likely make it run slower, so I've left it as-is for now.
+
+@<Globals@>=
+int texcnt ; /* btex..etex blocks so far */
+int verbcnt ; /* verbatimtex..etex blocks so far */
+char *bb, *tt, *aa; /* start of before, token, and after strings */
+char *buf; /* the input line */
+unsigned bufsize;
+
+@ @<Set initial values@>=
+mpx->bufsize = 1000;
+
+@ This function returns NULL on EOF, otherwise it returns |buf|.
+
+@c
+static char *mpx_getline(MPX mpx, FILE *mpfile) {
+ int c;
+ unsigned loc = 0;
+ if (feof(mpfile))
+ return NULL;
+ if (mpx->buf==NULL)
+ mpx->buf = xmalloc(mpx->bufsize,1);
+ while ((c = getc(mpfile)) != EOF && c != '\n' && c != '\r') {
+ mpx->buf[loc++] = c;
+ if (loc == mpx->bufsize) {
+ char *temp = mpx->buf;
+ unsigned n = mpx->bufsize + (mpx->bufsize>>4);
+ if (n>MAXINT)
+ mpx_abort(mpx,"Line is too long");
+ mpx->buf = xmalloc(n,1);
+ memcpy(mpx->buf,temp,mpx->bufsize);
+ free(temp);
+ mpx->bufsize = n;
+ }
+ }
+ mpx->buf[loc] = 0;
+ if (c == '\r') {
+ c = getc(mpfile);
+ if (c != '\n')
+ ungetc(c, mpfile);
+ }
+ mpx->lnno++;
+ return mpx->buf;
+}
+
+
+@ Return nonzero if a prefix of string $s$ matches the null-terminated string $t$
+and the next character is not a letter or an underscore.
+
+@c
+static int mpx_match_str(char *s, char *t) {
+ while (*t != 0) {
+ if (*s != *t)
+ return 0;
+ s++;
+ t++;
+ }
+ if ((*s>= 'a' && *s<='z') || (*s>= 'A' && *s<='Z') || *s == '_')
+ return 0;
+ return 1;
+}
+
+
+@ This function tries to express $s$ as the concatenation of three
+strings $b$, $t$, $a$, with the global pointers $bb$, $tt$, and $aa$ set to the
+start of the corresponding strings. String $t$ is either a quote mark,
+a percent sign, or an alphabetic token \.{btex}, \.{etex}, or
+\.{verbatimtex}. (An alphabetic token is a maximal sequence of letters
+and underscores.) If there are several possible substrings $t$, we
+choose the leftmost one. If there is no such $t$, we set $b=s$ and return 0.
+
+@c
+static int mpx_getbta(MPX mpx, char *s) {
+ int ok = 1; /* zero if last character was |a-z|, |A-Z|, or |_| */
+ mpx->bb = s;
+ for (mpx->tt = mpx->bb; *(mpx->tt) != 0; mpx->tt++) {
+ switch (*(mpx->tt)) {
+ case '"':
+ case '%':
+ mpx->aa = mpx->tt + 1;
+ return 1;
+ case 'b':
+ if (ok && mpx_match_str(mpx->tt, "btex")) {
+ mpx->aa = mpx->tt + 4;
+ return 1;
+ } else
+ ok = 0;
+ break;
+ case 'e':
+ if (ok && mpx_match_str(mpx->tt, "etex")) {
+ mpx->aa = mpx->tt + 4;
+ return 1;
+ } else
+ ok = 0;
+ break;
+ case 'v':
+ if (ok && mpx_match_str(mpx->tt, "verbatimtex")) {
+ mpx->aa = mpx->tt + 11;
+ return 1;
+ } else
+ ok = 0;
+ break;
+ default:
+ if ((*(mpx->tt) >= 'a' && *(mpx->tt) <= 'z') ||
+ (*(mpx->tt) >= 'A' && *(mpx->tt) <= 'Z') ||
+ (*(mpx->tt) == '_'))
+ ok = 0;
+ else
+ ok = 1;
+ }
+ }
+ mpx->aa = mpx->tt;
+ return 0;
+}
+
+@ @c
+static void mpx_copy_mpto (MPX mpx, FILE *outfile) {
+ char *s; /* where a string to print stops */
+ char *t; /* for finding start of last line */
+ char c;
+ char *res = NULL;
+ do {
+ if (*mpx->aa == 0) {
+ if ((mpx->aa = mpx_getline(mpx,mpx->mpfile)) == NULL) {
+ mpx_error(mpx,"btex section does not end");
+ }
+ }
+ if (mpx_getbta(mpx, mpx->aa) && *(mpx->tt) == 'e') {
+ s = mpx->tt;
+ } else {
+ if (*(mpx->tt) == 'b')
+ mpx_error(mpx,"btex in TeX mode");
+ if (*(mpx->tt) == 'v')
+ mpx_error(mpx,"verbatimtex in TeX mode");
+ s = mpx->aa;
+ }
+ c = *s;
+ *s = 0;
+ if (res==NULL) {
+ res = xmalloc(strlen(mpx->bb)+2,1);
+ res = strncpy(res,mpx->bb,(strlen(mpx->bb)+1));
+ } else {
+ res = xrealloc(res,strlen(res)+strlen(mpx->bb)+2,1);
+ res = strncat(res,mpx->bb, strlen(mpx->bb));
+ }
+ if (c == '\0')
+ res = strncat(res, "\n", 1);
+ *s = c;
+ } while (*(mpx->tt) != 'e');
+ /* whitespace at the end */
+ for (s = res + strlen(res) - 1;
+ s >= res && (*s == ' ' || *s == '\t' || *s == '\r' || *s == '\n'); s--);
+ t = s;
+ *(++s) = '\0';
+ /* whitespace at the start */
+ for (s = res;
+ s < (res + strlen(res)) && (*s == ' ' || *s == '\t' || *s == '\r'
+ || *s == '\n'); s++);
+ for (; *t != '\n' && t > s; t--);
+ fprintf(outfile,"%s", s);
+ /* put no |%| at end if it's only 1 line total, starting with |%|;
+ * this covers the special case |%&format| in a single line. */
+ if (t != s || *t != '%')
+ fprintf(outfile,"%%");
+ free(res);
+}
+
+
+@ Static strings for mpto
+
+@c
+static const char *mpx_predoc[] = {"", ".po 0\n"};
+static const char *mpx_postdoc[] = { "\\end{document}\n", ""};
+static const char *mpx_pretex1[] = {
+ "\\gdef\\mpxshipout{\\shipout\\hbox\\bgroup%\n"
+ " \\setbox0=\\hbox\\bgroup}%\n"
+ "\\gdef\\stopmpxshipout{\\egroup"
+ " \\dimen0=\\ht0 \\advance\\dimen0\\dp0\n"
+ " \\dimen1=\\ht0 \\dimen2=\\dp0\n"
+ " \\setbox0=\\hbox\\bgroup\n"
+ " \\box0\n"
+ " \\ifnum\\dimen0>0 \\vrule width1sp height\\dimen1 depth\\dimen2 \n"
+ " \\else \\vrule width1sp height1sp depth0sp\\relax\n"
+ " \\fi\\egroup\n"
+ " \\ht0=0pt \\dp0=0pt \\box0 \\egroup}\n"
+ "\\mpxshipout%% line %d %s\n", ".lf %d %s\n" };
+static const char *mpx_pretex[] = { "\\mpxshipout%% line %d %s\n", ".bp\n.lf %d %s\n" };
+static const char *mpx_posttex[] = { "\n\\stopmpxshipout\n", "\n" };
+static const char *mpx_preverb1[] = {"", ".lf %d %s\n" }; /* if very first instance */
+static const char *mpx_preverb[] = { "%% line %d %s\n", ".lf %d %s\n"}; /* all other instances */
+static const char *mpx_postverb[] = { "\n", "\n" } ;
+
+@ @c
+static void mpx_mpto(MPX mpx, char *tmpname, char *mptexpre) {
+ FILE *outfile;
+ int mode = mpx->mode;
+ char *mpname = mpx->mpname;
+ if (mode==mpx_tex_mode) {
+ TMPNAME_EXT(mpx->tex,".tex");
+ } else {
+ TMPNAME_EXT(mpx->tex,".i");
+ }
+ outfile = mpx_xfopen(mpx,mpx->tex, "wb");
+ if (mode==mpx_tex_mode) {
+ FILE *fr;
+ if ((fr = fopen(mptexpre, "r"))!= NULL) {
+ while (mpx_getline(mpx, fr) != NULL)
+ fputs(mpx->buf, outfile);
+ mpx_fclose(mpx,fr);
+ }
+ }
+ mpx->mpfile = mpx_xfopen(mpx,mpname, "r");
+ fprintf(outfile,"%s", mpx_predoc[mode]);
+ while (mpx_getline(mpx, mpx->mpfile) != NULL)
+ @<Do a line@>;
+ fprintf(outfile,"%s", mpx_postdoc[mode]);
+ mpx_fclose(mpx,mpx->mpfile);
+ mpx_fclose(mpx,outfile);
+ mpx->lnno = 0;
+}
+
+@
+@<Do a line@>=
+{
+ mpx->aa = mpx->buf;
+ while (mpx_getbta(mpx, mpx->aa)) {
+ if (*(mpx->tt) == '%') {
+ break;
+ } else if (*(mpx->tt) == '"') {
+ do {
+ if (!mpx_getbta(mpx, mpx->aa))
+ mpx_error(mpx,"string does not end");
+ } while (*(mpx->tt) != '"');
+ } else if (*(mpx->tt) == 'b') {
+ if (mpx->texcnt++ == 0)
+ fprintf(outfile,mpx_pretex1[mode], mpx->lnno, mpname);
+ else
+ fprintf(outfile,mpx_pretex[mode], mpx->lnno, mpname);
+ mpx_copy_mpto(mpx, outfile);
+ fprintf(outfile,"%s", mpx_posttex[mode]);
+ } else if (*(mpx->tt) == 'v') {
+ if (mpx->verbcnt++ == 0 && mpx->texcnt == 0)
+ fprintf(outfile,mpx_preverb1[mode], mpx->lnno, mpname);
+ else
+ fprintf(outfile,mpx_preverb[mode], mpx->lnno, mpname);
+ mpx_copy_mpto(mpx, outfile);
+ fprintf(outfile,"%s", mpx_postverb[mode]);
+ } else {
+ mpx_error(mpx,"unmatched etex");
+ }
+ }
+}
+
+@ @<Run |mpto| on the mp file@>=
+mpx_mpto(mpx, tmpname, mpxopt->mptexpre)
+
+@* DVItoMP Processing.
+
+The \.{DVItoMP} program reads binary device-independent (``\.{DVI}'')
+files that are produced by document compilers such as \TeX, and converts them
+into a symbolic form understood by \MP. It is loosely based on the \.{DVItype}
+utility program that produces a more faithful symbolic form of a \.{DVI} file.
+
+The output file is a sequence of \MP\ picture expressions, one for every page
+in the \.{DVI} file. It makes no difference to \.{DVItoMP} where the \.{DVI}
+file comes from, but it is intended to process the result of running \TeX\
+or \LaTeX\ on the output of the extraction process that is defined above.
+Such a \.{DVI} file will contain one page for every \.{btex}$\ldots$\.{etex}
+block in the original input. Processing with \.{DVItoMP} creates a
+corresponding sequence of \MP\ picture expressions for use as an auxiliary
+input file. Since \MP\ expects such files to have the extension \.{.MPX},
+the output of \.{DVItoMP} is sometimes called an ``\.{MPX}'' file.
+
+@ The following parameters can be changed at compile time to extend or
+reduce \.{DVItoMP}'s capacity.
+
+TODO: dynamic reallocation
+
+@d virtual_space 1000000 /* maximum total bytes of typesetting commands for virtual fonts */
+@d max_fonts 1000 /* maximum number of distinct fonts per \.{DVI} file */
+@d max_fnums 3000 /* maximum number of fonts plus fonts local to virtual fonts */
+@d max_widths (256*max_fonts) /* maximum number of different characters among all fonts */
+@d line_length 79 /* maximum output line length (must be at least 60) */
+@d stack_size 100 /* \.{DVI} files shouldn't |push| beyond this depth */
+@d font_tolerance 0.00001
+ /* font sizes should match to within this multiple of $2^{20}$ \.{DVI} units */
+
+@ If the \.{DVI} file is badly malformed, the whole process must be aborted;
+\.{DVItoMP} will give up, after issuing an error message about the symptoms
+that were noticed.
+
+@d bad_dvi(A) mpx_abort(mpx,"Bad DVI file: " A "!")
+@d bad_dvi_two(A,B) mpx_abort(mpx,"Bad DVI file: %s !", A, B)
+@.Bad DVI file@>
+
+@* The character set.
+
+Like all programs written with the \.{WEB} system, \.{DVItoMP} can be
+used with any character set. It an identify transfrom internally, because
+the programming for portable input-output is easier when a fixed internal
+code is used, and because \.{DVI} files use ASCII code for file names.
+
+In the conversion from Pascal to C, the |xchr| array has been removed.
+Because some systems may still want to change the input--output character
+set, the accesses to |xchr| and |printable| are replaced by macro calls.
+
+@d printable(c) (isprint(c) && c < 128 && c!='"')
+@d xchr(A) (A)
+
+@ @c
+static void mpx_open_mpxfile (MPX mpx) { /* prepares to write text on |mpxfile| */
+ mpx->mpxfile = mpx_xfopen (mpx,mpx->mpxname, "wb");
+}
+
+@* Device-independent file format.
+The format of \.{DVI} files is described in many places including
+\.{dvitype.web} and Volume~B of D.~E. Knuth's {\sl Computers and Typesetting}.
+This program refers to the following command codes.
+
+@d id_byte 2 /* identifies the kind of \.{DVI} files described here */
+@#
+@d set_char_0 0 /* typeset character 0 and move right */
+@d set1 128 /* typeset a character and move right */
+@d set_rule 132 /* typeset a rule and move right */
+@d put1 133 /* typeset a character */
+@d put_rule 137 /* typeset a rule */
+@d nop 138 /* no operation */
+@d bop 139 /* beginning of page */
+@d eop 140 /* ending of page */
+@d push 141 /* save the current positions */
+@d pop 142 /* restore previous positions */
+@d right1 143 /* move right */
+@d w0 147 /* move right by |w| */
+@d w1 148 /* move right and set |w| */
+@d x0 152 /* move right by |x| */
+@d x1 153 /* move right and set |x| */
+@d down1 157 /* move down */
+@d y0 161 /* move down by |y| */
+@d y1 162 /* move down and set |y| */
+@d z0 166 /* move down by |z| */
+@d z1 167 /* move down and set |z| */
+@d fnt_num_0 171 /* set current font to 0 */
+@d fnt1 235 /* set current font */
+@d xxx1 239 /* extension to \.{DVI} primitives */
+@d xxx4 242 /* potentially long extension to \.{DVI} primitives */
+@d fnt_def1 243 /* define the meaning of a font number */
+@d pre 247 /* preamble */
+@d post 248 /* postamble beginning */
+@d post_post 249 /* postamble ending */
+@d undefined_commands 250: case 251: case 252: case 253: case 254: case 255
+
+@* Input from binary files.
+
+@ The program deals with two binary file variables: |dvi_file| is the main
+input file that we are translating into symbolic form, and |tfm_file| is
+the current font metric file from which character-width information is
+being read. It is convenient to have a throw-away variable for function
+results when reading parts of the files that are being skipped.
+
+@<Glob...@>=
+FILE * dvi_file; /* the input file */
+FILE * tfm_file; /* a font metric file */
+FILE * vf_file; /* a virtual font file */
+
+@ Prepares to read packed bytes in |dvi_file|
+@c
+static void mpx_open_dvi_file (MPX mpx) {
+ mpx->dvi_file = fopen(mpx->dviname,"rb");
+ if (mpx->dvi_file==NULL)
+ mpx_abort(mpx,"DVI generation failed");
+}
+
+@ Prepares to read packed bytes in |tfm_file|
+@c
+static web_boolean mpx_open_tfm_file (MPX mpx) {
+ mpx->tfm_file = mpx_fsearch(mpx, mpx->cur_name, mpx_tfm_format);
+ if (mpx->tfm_file == NULL)
+ mpx_abort(mpx,"Cannot find TFM %s", mpx->cur_name);
+ free (mpx->cur_name); /* We |xmalloc|'d this before we got called. */
+ return true; /* If we get here, we succeeded. */
+}
+
+@ Prepares to read packed bytes in |vf_file|.
+It's ok if the \.{VF} file doesn't exist.
+
+@c
+static web_boolean mpx_open_vf_file (MPX mpx) {
+ mpx->vf_file = mpx_fsearch(mpx, mpx->cur_name, mpx_vf_format);
+ if (mpx->vf_file) {
+ free (mpx->cur_name);
+ return true;
+ }
+ return false;
+}
+
+@ If you looked carefully at the preceding code, you probably asked,
+``What is |cur_name|?'' Good question. It's a global
+variable: |cur_name| is a string variable that will be set to the
+current font metric file name before |open_tfm_file| or |open_vf_file|
+is called.
+
+@<Glob...@>=
+char *cur_name; /* external name */
+
+@ It turns out to be convenient to read four bytes at a time, when we are
+inputting from \.{TFM} files. The input goes into global variables
+|b0|, |b1|, |b2|, and |b3|, with |b0| getting the first byte and |b3|
+the fourth.
+
+@<Glob...@>=
+int b0, b1, b2, b3; /* four bytes input at once */
+
+@ The |read_tfm_word| procedure sets |b0| through |b3| to the next
+four bytes in the current \.{TFM} file.
+
+@c
+static void mpx_read_tfm_word (MPX mpx) {
+ mpx->b0 = getc(mpx->tfm_file);
+ mpx->b1 = getc(mpx->tfm_file);
+ mpx->b2 = getc(mpx->tfm_file);
+ mpx->b3 = getc(mpx->tfm_file);
+}
+
+@ Input can come from from three different sources depending on the settings
+of global variables. When |vf_reading| is true, we read from the \.{VF} file.
+Otherwise, input can either come directly from |dvi_file| or from a buffer
+|cmd_buf|. The latter case applies whenever |buf_ptr<virtual_space|.
+
+@<Glob...@>=
+web_boolean vf_reading; /* should input come from |vf_file|? */
+unsigned char cmd_buf[(virtual_space+1)]; /* commands for virtual characters */
+unsigned int buf_ptr; /* |cmd_buf| index for the next byte */
+
+@ @<Set init...@>=
+mpx->vf_reading=false;
+mpx->buf_ptr=virtual_space;
+
+@ We shall use a set of simple functions to read the next byte or bytes from the
+current input source. There are seven possibilities, each of which is treated
+as a separate function in order to minimize the overhead for subroutine calls.
+
+@c
+static web_integer mpx_get_byte (MPX mpx) { /* returns the next byte, unsigned */
+ unsigned char b;
+ @<Read one byte into |b|@>;
+ return b;
+}
+
+static web_integer mpx_signed_byte (MPX mpx) { /* returns the next byte, signed */
+ unsigned char b;
+ @<Read one byte into |b|@>;
+ return ( b<128 ? b : (b-256));
+}
+
+static web_integer mpx_get_two_bytes (MPX mpx) { /* returns the next two bytes, unsigned */
+ unsigned char a,b;
+ a=0; b=0; /* for compiler warnings */
+ @<Read two bytes into |a| and |b|@>;
+ return (a*(int)(256)+b);
+}
+
+static web_integer mpx_signed_pair (MPX mpx) { /* returns the next two bytes, signed */
+ unsigned char a,b;
+ a=0; b=0; /* for compiler warnings */
+ @<Read two bytes into |a| and |b|@>;
+ if ( a<128 ) return (a*256+b);
+ else return ((a-256)*256+b);
+}
+
+static web_integer mpx_get_three_bytes (MPX mpx) { /* returns the next three bytes, unsigned */
+ unsigned char a,b,c;
+ a=0; b=0; c=0; /* for compiler warnings */
+ @<Read three bytes into |a|, |b|, and~|c|@>;
+ return ((a*(int)(256)+b)*256+c);
+}
+
+static web_integer mpx_signed_trio (MPX mpx) { /* returns the next three bytes, signed */
+ unsigned char a,b,c;
+ a=0; b=0; c=0; /* for compiler warnings */
+ @<Read three bytes into |a|, |b|, and~|c|@>;
+ if ( a<128 ) return ((a*(int)(256)+b)*256+c);
+ else return (((a-(int)(256))*256+b)*256+c);
+}
+
+static web_integer mpx_signed_quad (MPX mpx) { /* returns the next four bytes, signed */
+ unsigned char a,b,c,d;
+ a=0; b=0; c=0; d=0; /* for compiler warnings */
+ @<Read four bytes into |a|, |b|, |c|, and~|d|@>;
+ if ( a<128 ) return (((a*(int)(256)+b)*256+c)*256+d);
+ else return ((((a-256)*(int)(256)+b)*256+c)*256+d);
+}
+
+@ @<Read one byte into |b|@>=
+if ( mpx->vf_reading ) {
+ b = (unsigned char)getc(mpx->vf_file);
+} else if ( mpx->buf_ptr==virtual_space ) {
+ b = (unsigned char)getc(mpx->dvi_file);
+} else {
+ b=mpx->cmd_buf[mpx->buf_ptr];
+ incr(mpx->buf_ptr);
+}
+
+@ @<Read two bytes into |a| and |b|@>=
+if ( mpx->vf_reading ) {
+ a = (unsigned char)getc(mpx->vf_file);
+ b = (unsigned char)getc(mpx->vf_file);
+} else if ( mpx->buf_ptr==virtual_space ) {
+ a = (unsigned char)getc(mpx->dvi_file);
+ b = (unsigned char)getc(mpx->dvi_file);
+} else if ( mpx->buf_ptr+2>mpx->n_cmds ) {
+ mpx_abort(mpx,"Error detected while interpreting a virtual font");
+@.Error detected while...@>
+} else {
+ a=mpx->cmd_buf[mpx->buf_ptr];
+ b=mpx->cmd_buf[mpx->buf_ptr+1];
+ mpx->buf_ptr+=2;
+}
+
+@ @<Read three bytes into |a|, |b|, and~|c|@>=
+if ( mpx->vf_reading ) {
+ a = (unsigned char)getc(mpx->vf_file);
+ b = (unsigned char)getc(mpx->vf_file);
+ c = (unsigned char)getc(mpx->vf_file);
+} else if ( mpx->buf_ptr==virtual_space ) {
+ a = (unsigned char)getc(mpx->dvi_file);
+ b = (unsigned char)getc(mpx->dvi_file);
+ c = (unsigned char)getc(mpx->dvi_file);
+} else if ( mpx->buf_ptr+3>mpx->n_cmds ) {
+ mpx_abort(mpx,"Error detected while interpreting a virtual font");
+@.Error detected while...@>
+} else {
+ a=mpx->cmd_buf[mpx->buf_ptr];
+ b=mpx->cmd_buf[mpx->buf_ptr+1];
+ c=mpx->cmd_buf[mpx->buf_ptr+2];
+ mpx->buf_ptr+=3;
+}
+
+@ @<Read four bytes into |a|, |b|, |c|, and~|d|@>=
+if ( mpx->vf_reading ) {
+ a = (unsigned char)getc(mpx->vf_file);
+ b = (unsigned char)getc(mpx->vf_file);
+ c = (unsigned char)getc(mpx->vf_file);
+ d = (unsigned char)getc(mpx->vf_file);
+} else if ( mpx->buf_ptr==virtual_space ) {
+ a = (unsigned char)getc(mpx->dvi_file);
+ b = (unsigned char)getc(mpx->dvi_file);
+ c = (unsigned char)getc(mpx->dvi_file);
+ d = (unsigned char)getc(mpx->dvi_file);
+} else if ( mpx->buf_ptr+4>mpx->n_cmds ) {
+ mpx_abort(mpx,"Error detected while interpreting a virtual font");
+@.Error detected while...@>
+} else {
+ a=mpx->cmd_buf[mpx->buf_ptr];
+ b=mpx->cmd_buf[mpx->buf_ptr+1];
+ c=mpx->cmd_buf[mpx->buf_ptr+2];
+ d=mpx->cmd_buf[mpx->buf_ptr+3];
+ mpx->buf_ptr+=4;
+}
+
+@* Data structures for fonts.
+
+\.{DVI} file format does not include information about character widths, since
+that would tend to make the files a lot longer. But a program that reads
+a \.{DVI} file is supposed to know the widths of the characters that appear
+in \\{set\_char} commands. Therefore \.{DVItoMP} looks at the font metric
+(\.{TFM}) files for the fonts that are involved.
+@.TFM {\rm files}@>
+
+@ For purposes of this program, the only thing we need to know about a
+given character |c| in a non-virtual font |f| is the width. For the font as
+a whole, all we need is the symbolic name to use in the \.{MPX} file.
+
+This information appears implicitly in the following data
+structures. The current number of fonts defined is |nf|. Each such font has
+an internal number |f|, where |0<=f<nf|. There is also an external number
+that identifies the font in the \.{DVI} file. The correspondence is
+maintained in arrays |font_num| and |internal_num| so that |font_num[i]|
+is the external number for |f=internal_num[i]|.
+The external name of this font is the string that occupies |font_name[f]|.
+The legal characters run from |font_bc[f]| to |font_ec[f]|, inclusive.
+The \.{TFM} file can specify that some of these are invalid, but this doesn't
+concern \.{DVItoMP} because it does not do extensive error checking.
+The width of character~|c| in font~|f| is given by
+|char_width(f,c)=width[info_base[f]+c]|, and |info_ptr| is the
+first unused position of the |width| array.
+
+If font~|f| is a virtual font, there is a list of \.{DVI} commands for each
+character. These occupy consecutive positions in the |cmd_buf| array with
+the commands for character~|c| starting at
+|start_cmd(f,c)=cmd_ptr[info_base[f]+c]| and ending just before
+|start_cmd(f,c+1)|. Font numbers used when interpreting these \.{DVI}
+commands occupy positions |fbase[f]| through |ftop[f]-1| in the |font_num|
+table and the |internal_num| array gives the corresponding internal font
+numbers. If such an internal font number~|i| does not correspond to
+some font occuring in the \.{DVI} file, then |font_num[i]| has not been
+assigned a meaningful value; this is indicated by |local_only[i]=true|.
+
+If font~|f| is not virtual, then |fbase[f]=0| and |ftop[f]=0|. The |start_cmd|
+values are ignored in this case.
+
+@d char_width(A,B) mpx->width[mpx->info_base[(A)]+(B)]
+@d start_cmd(A,B) mpx->cmd_ptr[mpx->info_base[(A)]+(B)]
+
+@<Glob...@>=
+web_integer font_num[(max_fnums+1)]; /* external font numbers */
+web_integer internal_num[(max_fnums+1)]; /* internal font numbers */
+web_boolean local_only[(max_fnums+1)]; /* |font_num| meaningless? */
+char *font_name[(max_fonts+1)]; /* starting positions of external font names */
+double font_scaled_size[(max_fonts+1)]; /* scale factors over $2^{20}$ */
+double font_design_size[(max_fonts+1)]; /* design sizes over $2^{20}$ */
+web_integer font_check_sum[(max_fonts+1)]; /* check sum from the |font_def| */
+web_integer font_bc[(max_fonts+1)]; /* beginning characters in fonts */
+web_integer font_ec[(max_fonts+1)]; /* ending characters in fonts */
+web_integer info_base[(max_fonts+1)]; /* index into |width| and |cmd_ptr| tables */
+web_integer width[(max_widths+1)];
+ /* character widths, in units $2^{-20}$ of design size */
+web_integer fbase[(max_fonts+1)]; /* index into |font_num| for local fonts */
+web_integer ftop[(max_fonts+1)]; /* |font_num| index where local fonts stop */
+web_integer cmd_ptr[(max_widths+1)]; /* starting positions in |cmd_buf| */
+unsigned int nfonts; /* the number of known fonts */
+unsigned int vf_ptr; /* next |font_num| entry for virtual font font tables */
+unsigned int info_ptr; /* allocation pointer for |width| and |cmd_ptr| tables */
+unsigned int n_cmds; /* number of occupied cells in |cmd_buf| */
+unsigned int cur_fbase, cur_ftop;
+ /* currently applicable part of the |font_num| table */
+
+@ @<Set init...@>=
+mpx->nfonts=0; mpx->info_ptr=0; mpx->font_name[0]=0;
+mpx->vf_ptr=max_fnums;
+mpx->cur_fbase=0; mpx->cur_ftop=0;
+
+@ Printing the name of a given font is easy except that a procedure |print_char|
+is needed to actually send an |ASCII_code| to the \.{MPX} file.
+
+@c @<Declare subroutines for printing strings@>@;
+static void mpx_print_font (MPX mpx, web_integer f) { /* |f| is an internal font number */
+ if ( (f<0)||(f>=(int)mpx->nfonts) ) {
+ bad_dvi("Undefined font");
+ } else {
+ char *s = mpx->font_name[f];
+ while (*s) {
+ mpx_print_char(mpx,(unsigned char)*s);
+ s++;
+ }
+ }
+}
+
+@ Sometimes a font name is needed as part of an error message.
+
+@d font_warn(A,B) mpx_warn (mpx,"%s %s",A,mpx->font_name[(B)])
+@d font_error(A,B) mpx_error(mpx,"%s %s",A,mpx->font_name[(B)])
+@d font_abort(A,B) mpx_abort(mpx,"%s %s",A,mpx->font_name[(B)])
+
+
+@ When we encounter a font definition, we save the name, checksum, and size
+information, but we don't actually read the \.{TFM} or \.{VF} file until we
+are about to use the font. If a matching font is not already defined, we then
+allocate a new internal font number.
+
+The following subroutine does the necessary things when a \\{fnt\_def} command
+is encountered in the \.{DVI} file or in a \.{VF} file. It assumes that the
+first argument has already been parsed and is given by the parameter~|e|.
+
+@c @<Declare a function called |match_font|@>@;
+static void mpx_define_font (MPX mpx, web_integer e) { /* |e| is an external font number */
+ unsigned i; /* index into |font_num| and |internal_num| */
+ web_integer n; /* length of the font name and area */
+ web_integer k; /* general purpose loop counter */
+ web_integer x; /* a temporary value for scaled size computation */
+ if ( mpx->nfonts==max_fonts )
+ mpx_abort(mpx,"DVItoMP capacity exceeded (max fonts=%d)!", max_fonts);
+@.DVItoMP capacity exceeded...@>
+ @<Allocate an index |i| into the |font_num| and |internal_num| tables@>;
+ @<Read the font parameters into position for font |nf|@>;
+ mpx->internal_num[i]=mpx_match_font(mpx, mpx->nfonts,true);
+ if ( mpx->internal_num[i]==(int)mpx->nfonts ) {
+ mpx->info_base[mpx->nfonts]=max_widths; /* indicate that the info isn't loaded yet */
+ mpx->local_only[mpx->nfonts]=mpx->vf_reading; incr(mpx->nfonts);
+ }
+}
+
+@ @<Allocate an index |i| into the |font_num| and |internal_num| tables@>=
+if ( mpx->vf_ptr==mpx->nfonts )
+ mpx_abort(mpx,"DVItoMP capacity exceeded (max font numbers=%d)", max_fnums);
+@.DVItoMP capacity exceeded...@>
+if ( mpx->vf_reading ) {
+ mpx->font_num[mpx->nfonts]=0; i=mpx->vf_ptr; decr(mpx->vf_ptr);
+} else {
+ i=mpx->nfonts;
+}
+mpx->font_num[i]=e
+
+@ @<Read the font parameters into position for font |nf|@>=
+mpx->font_check_sum[mpx->nfonts]=mpx_signed_quad(mpx);
+@<Read |font_scaled_size[nf]| and |font_design_size[nf]|@>;
+n=mpx_get_byte(mpx); /* that is the area */
+n=n+mpx_get_byte(mpx);
+mpx->font_name[mpx->nfonts]=xmalloc((size_t)(n+1),1);
+for (k=0;k<n;k++)
+ mpx->font_name[mpx->nfonts][k]=mpx_get_byte(mpx);
+mpx->font_name[mpx->nfonts][k]=0
+
+@ The scaled size and design size are stored in \.{DVI} units divided by $2^{20}$.
+The units for scaled size are a little different if we are reading a virtual
+font, but this will be corrected when the scaled size is used. The scaled size
+also needs to be truncated to at most 23 significant bits in order to make
+the character width calculation match what \TeX\ does.
+
+@<Read |font_scaled_size[nf]| and |font_design_size[nf]|@>=
+x=mpx_signed_quad(mpx);
+k=1;
+while ( mpx->x>040000000 ) {
+ x= x / 2; k=k+k;
+}
+mpx->font_scaled_size[mpx->nfonts]=x*k/1048576.0;
+if ( mpx->vf_reading )
+ mpx->font_design_size[mpx->nfonts]=mpx_signed_quad(mpx)*mpx->dvi_per_fix/1048576.0;
+else mpx->font_design_size[mpx->nfonts]=mpx_signed_quad(mpx)/1048576.0;
+
+@ @<Glob...@>=
+double dvi_per_fix; /* converts points scaled $2^{20}$ to \.{DVI} units */
+
+@ The |match_font| function tries to find a match for the font with internal
+number~|ff|, returning |nf| or the number of the matching font. If
+|exact=true|, the name and scaled size should match. Otherwise the scaled
+size need not match but the font found must be already loaded, not just
+defined.
+
+@<Declare a function called |match_font|@>=
+static web_integer mpx_match_font (MPX mpx, unsigned ff, web_boolean exact) {
+ unsigned f; /* font number being tested */
+ for (f=0; f<mpx->nfonts ; f++) {
+ if ( f!=ff ) {
+ @<Compare the names of fonts |f| and |ff|; |continue| if they differ@>;
+ if ( exact ) {
+ if ( fabs(mpx->font_scaled_size[f]-mpx->font_scaled_size[ff])<= font_tolerance ) {
+ if ( ! mpx->vf_reading ) {
+ if ( mpx->local_only[f] ) {
+ mpx->font_num[f]=mpx->font_num[ff]; mpx->local_only[f]=false;
+ } else if ( mpx->font_num[f]!=mpx->font_num[ff] ) {
+ continue;
+ }
+ }
+ break;
+ }
+ } else if ( mpx->info_base[f]!=max_widths ) {
+ break;
+ }
+ }
+ }
+ if ( f<mpx->nfonts ) {
+ @<Make sure fonts |f| and |ff| have matching design sizes and checksums@>;
+ }
+ return (web_integer)f;
+}
+
+@ @<Compare the names of fonts |f| and |ff|; |continue| if they differ@>=
+if (strcmp(mpx->font_name[f],mpx->font_name[ff]))
+ continue
+
+@ @<Make sure fonts |f| and |ff| have matching design sizes and checksums@>=
+if ( fabs(mpx->font_design_size[f]-mpx->font_design_size[ff]) > font_tolerance ) {
+ font_error("Inconsistent design sizes given for ",ff);
+@.Inconsistent design sizes@>
+} else if ( mpx->font_check_sum[f]!=mpx->font_check_sum[ff] ) {
+ font_warn("Checksum mismatch for ", ff);
+@.Checksum mismatch@>
+}
+
+@* Reading ordinary fonts.
+An auxiliary array |in_width| is used to hold the widths as they are
+input. The global variable |tfm_check_sum| is set to the check sum that
+appears in the current \.{TFM} file.
+
+@<Glob...@>=
+web_integer in_width[256]; /* \.{TFM} width data in \.{DVI} units */
+web_integer tfm_check_sum; /* check sum found in |tfm_file| */
+
+@ Here is a procedure that absorbs the necessary information from a
+\.{TFM} file, assuming that the file has just been successfully reset
+so that we are ready to read its first byte. (A complete description of
+\.{TFM} file format appears in the documentation of \.{TFtoPL} and will
+not be repeated here.) The procedure does not check the \.{TFM} file
+for validity, nor does it give explicit information about what is
+wrong with a \.{TFM} file that proves to be invalid. The procedure simply
+aborts the program if it detects anything amiss in the \.{TFM} data.
+
+@c
+static void mpx_in_TFM (MPX mpx,web_integer f) {
+ /* input \.{TFM} data for font |f| or abort */
+ web_integer k; /* index for loops */
+ int lh; /* length of the header data, in four-byte words */
+ int nw; /* number of words in the width table */
+ unsigned wp; /* new value of |info_ptr| after successful input */
+ @<Read past the header data; |abort| if there is a problem@>;
+ @<Store character-width indices at the end of the |width| table@>;
+ @<Read the width values into the |in_width| table@>;
+ @<Move the widths from |in_width| to |width|@>;
+ mpx->fbase[f]=0; mpx->ftop[f]=0;
+ mpx->info_ptr=wp;
+ return;
+}
+
+@ @<Read past the header...@>=
+mpx_read_tfm_word(mpx); lh=mpx->b2*(int)(256)+mpx->b3;
+mpx_read_tfm_word(mpx);
+mpx->font_bc[f]=mpx->b0*(int)(256)+mpx->b1;
+mpx->font_ec[f]=mpx->b2*(int)(256)+mpx->b3;
+if ( mpx->font_ec[f]<mpx->font_bc[f] ) mpx->font_bc[f]=mpx->font_ec[f]+1;
+if ( mpx->info_ptr+mpx->font_ec[f]-mpx->font_bc[f]+1>max_widths )
+ mpx_abort(mpx,"DVItoMP capacity exceeded (width table size=%d)!",max_widths);
+@.DVItoMP capacity exceeded...@>
+wp=mpx->info_ptr+mpx->font_ec[f]-mpx->font_bc[f]+1;
+mpx_read_tfm_word(mpx); nw=mpx->b0*256+mpx->b1;
+if ( (nw==0)||(nw>256) )
+ font_abort("Bad TFM file for ",f);
+@.Bad TFM file@>
+for (k=1;k<=3+lh;k++) {
+ if ( feof(mpx->tfm_file) )
+ font_abort("Bad TFM file for ",f);
+@.Bad TFM file@>
+ mpx_read_tfm_word(mpx);
+ if ( k==4 ) {
+ if ( mpx->b0<128 )
+ mpx->tfm_check_sum=((mpx->b0*(int)(256)+mpx->b1)*256+mpx->b2)*256+mpx->b3;
+ else
+ mpx->tfm_check_sum=(((mpx->b0-256)*(int)(256)+mpx->b1)*256+mpx->b2)*256+mpx->b3;
+ }
+}
+
+@ @<Store character-width indices...@>=
+if ( wp>0 ) {
+ for (k=(int)mpx->info_ptr;k<=(int)wp-1;k++ ) {
+ mpx_read_tfm_word(mpx);
+ if ( mpx->b0>nw )
+ font_abort("Bad TFM file for ",f);
+@.Bad TFM file@>
+ mpx->width[k]=mpx->b0;
+ }
+}
+
+@ No fancy width calculation is needed here because \.{DVItoMP} stores
+widths in their raw form as multiples of the design size scaled by $2^{20}$.
+The |font_scaled_size| entries have been computed so that the final width
+compution can be done in floating point if enough precision is available.
+
+@<Read the width values into the |in_width| table@>=
+for (k=0;k<=nw-1;k++) {
+ mpx_read_tfm_word(mpx);
+ if ( mpx->b0>127 ) mpx->b0=mpx->b0-256;
+ mpx->in_width[k]=((mpx->b0*0400+mpx->b1)*0400+mpx->b2)*0400+mpx->b3;
+}
+
+@ The width compution uses a scale factor |dvi_scale| that will be introduced
+later. It is equal to one when not typesetting a character from a virtual
+font. In that case, the following expressions do the width computation that is
+so important in \.{DVItype}. It is less important here because it is impractical
+to guarantee precise character positioning in \MP\ output. Nevertheless, the
+width compution will be precise if reals have at least 46-bit mantissas and
+|round(x-.5)| is equivalent to $\lfloor x\rfloor$. It may be a good idea to
+modify this computation if these conditions are not met.
+@^system dependencies@>
+
+@<Width of character |c| in font |f|@>=
+floor(mpx->dvi_scale*mpx->font_scaled_size[f]*char_width(f,c))
+
+@ @<Width of character |p| in font |cur_font|@>=
+floor(mpx->dvi_scale*mpx->font_scaled_size[cur_font]*char_width(cur_font,p))
+
+@ @<Move the widths from |in_width| to |width|@>=
+if ( mpx->in_width[0]!=0 )
+ font_abort("Bad TFM file for ",f); /* the first width should be zero */
+@.Bad TFM file@>
+mpx->info_base[f]=(int)(mpx->info_ptr-mpx->font_bc[f]);
+if ( wp>0 ) {
+ for (k=(int)mpx->info_ptr;k<=(int)wp-1;k++) {
+ mpx->width[k]=mpx->in_width[mpx->width[k]];
+ }
+}
+
+
+@* Reading virtual fonts.
+
+The |in_VF| procedure absorbs the necessary information from a \.{VF} file that
+has just been reset so that we are ready to read the first byte. (A complete
+description of \.{VF} file format appears in the documention of \.{VFtoVP}).
+Like |in_TFM|, this procedure simply aborts the program if it detects anything
+wrong with the \.{VF} file.
+
+@c
+@<Declare a function called |first_par|@>@;
+static void mpx_in_VF (MPX mpx, web_integer f) {
+ /* read \.{VF} data for font |f| or abort */
+ web_integer p; /* a byte from the \.{VF} file */
+ boolean was_vf_reading; /* old value of |vf_reading| */
+ web_integer c; /* the current character code */
+ web_integer limit; /* space limitations force character codes to be less than this */
+ web_integer w; /* a \.{TFM} width being read */
+ was_vf_reading=mpx->vf_reading; mpx->vf_reading=true;
+ @<Start reading the preamble from a \.{VF} file@>;@/
+ @<Initialize the data structures for the virtual font@>;@/
+ p=mpx_get_byte(mpx);
+ while ( p>=fnt_def1 ) {
+ if ( p>fnt_def1+3 )
+ font_abort("Bad VF file for ",f);
+ mpx_define_font(mpx, mpx_first_par(mpx, (unsigned int)p));
+ p=mpx_get_byte(mpx);
+ }
+ while ( p<=242 ) {
+ if ( feof(mpx->vf_file) )
+ font_abort("Bad VF file for ",f);
+ @<Read the packet length, character code, and \.{TFM} width@>;
+ @<Store the character packet in |cmd_buf|@>;
+ p=mpx_get_byte(mpx);
+ }
+ if ( p==post ) {
+ @<Finish setting up the data structures for the new virtual font@>;
+ mpx->vf_reading=was_vf_reading;
+ return;
+ }
+}
+
+@ @<Start reading the preamble from a \.{VF} file@>=
+p=mpx_get_byte(mpx);
+if ( p!=pre )
+ font_abort("Bad VF file for ",f);
+p=mpx_get_byte(mpx); /* fetch the identification byte */
+if ( p!=202 )
+ font_abort("Bad VF file for ",f);
+p=mpx_get_byte(mpx); /* fetch the length of the introductory comment */
+while ( p-->0 )
+ (void)mpx_get_byte(mpx);
+mpx->tfm_check_sum=mpx_signed_quad(mpx);
+(void)mpx_signed_quad(mpx); /* skip over the design size */
+
+@ @<Initialize the data structures for the virtual font@>=
+mpx->ftop[f]=(web_integer)mpx->vf_ptr;
+if ( mpx->vf_ptr==mpx->nfonts )
+ mpx_abort(mpx,"DVItoMP capacity exceeded (max font numbers=%d)", max_fnums);
+@.DVItoMP capacity exceeded...@>
+decr(mpx->vf_ptr);
+mpx->info_base[f]=(web_integer)mpx->info_ptr;
+limit=max_widths-mpx->info_base[f];@/
+mpx->font_bc[f]=limit; mpx->font_ec[f]=0
+
+@ @<Read the packet length, character code, and \.{TFM} width@>=
+if ( p==242 ) {
+ p=mpx_signed_quad(mpx); c=mpx_signed_quad(mpx); w=mpx_signed_quad(mpx);
+ if ( c<0 )
+ font_abort("Bad VF file for ",f);
+} else {
+ c=mpx_get_byte(mpx); w=mpx_get_three_bytes(mpx);
+}
+if ( c>=limit )
+ mpx_abort(mpx,"DVItoMP capacity exceeded (max widths=%d)", max_widths);
+@.DVItoMP capacity exceeded...@>
+if ( c<mpx->font_bc[f] ) mpx->font_bc[f]=c;
+if ( c>mpx->font_ec[f] ) mpx->font_ec[f]=c;
+char_width(f,c)=w
+
+@ @<Store the character packet in |cmd_buf|@>=
+if ( mpx->n_cmds+p>=virtual_space )
+ mpx_abort(mpx,"DVItoMP capacity exceeded (virtual font space=%d)",virtual_space);
+@.DVItoMP capacity exceeded...@>
+start_cmd(f,c)=(web_integer)mpx->n_cmds;
+while ( p>0 ) {
+ mpx->cmd_buf[mpx->n_cmds]=(unsigned char)mpx_get_byte(mpx);
+ incr(mpx->n_cmds); decr(p);
+}
+mpx->cmd_buf[mpx->n_cmds]=eop; /* add the end-of-packet marker */
+incr(mpx->n_cmds)
+
+@ There are unused |width| and |cmd_ptr| entries if |font_bc[f]>0| but it isn't
+worthwhile to slide everything down just to save a little space.
+
+@<Finish setting up the data structures for the new virtual font@>=
+mpx->fbase[f]=(web_integer)(mpx->vf_ptr+1);
+mpx->info_ptr=(unsigned int)(mpx->info_base[f]+mpx->font_ec[f]+1)
+
+
+@* Loading fonts.
+
+The character width information for a font is loaded when the font is selected
+for the first time. This information might already be loaded if the font has
+already been used at a different scale factor. Otherwise, we look for a \.{VF}
+file, or failing that, a \.{TFM} file. All this is done by the |select_font|
+function that takes an external font number~|e| and returns the corresponding
+internal font number with the width information loaded.
+
+@c
+static web_integer mpx_select_font (MPX mpx, web_integer e) {
+ int f; /* the internal font number */
+ int ff; /* internal font number for an existing version */
+ web_integer k; /* general purpose loop counter */
+ @<Set |f| to the internal font number that corresponds to |e|,
+ or |abort| if there is none@>;
+ if ( mpx->info_base[f]==max_widths ) {
+ ff=mpx_match_font(mpx, (unsigned)f,false);
+ if ( ff<(int)mpx->nfonts ) {
+ @<Make font |f| refer to the width information from font |ff|@>;
+ } else {
+ @<Move the \.{VF} file name into the |cur_name| string@>;
+ if ( mpx_open_vf_file(mpx) ) {
+ mpx_in_VF(mpx, f);
+ } else {
+ if ( ! mpx_open_tfm_file(mpx) )
+ font_abort("No TFM file found for ",f);
+@.no TFM file found@>
+ mpx_in_TFM(mpx, f);
+ }
+ @<Make sure the checksum in the font file matches the one given in the
+ |font_def| for font |f|@>;
+ }
+ @<Do any other initialization required for the new font |f|@>;
+ }
+ return f;
+}
+
+@ @<Set |f| to the internal font number that corresponds to |e|,...@>=
+if ( mpx->cur_ftop<=mpx->nfonts )
+ mpx->cur_ftop=mpx->nfonts;
+mpx->font_num[mpx->cur_ftop]=e;
+k=(web_integer)mpx->cur_fbase;
+while ((mpx->font_num[k]!=e)|| mpx->local_only[k] ) incr(k);
+if ( k==(int)mpx->cur_ftop )
+ mpx_abort(mpx,"Undefined font selected");
+f=mpx->internal_num[k]
+
+@ @<Make font |f| refer to the width information from font |ff|@>=
+{
+ mpx->font_bc[f]=mpx->font_bc[ff];
+ mpx->font_ec[f]=mpx->font_ec[ff];
+ mpx->info_base[f]=mpx->info_base[ff];
+ mpx->fbase[f]=mpx->fbase[ff];
+ mpx->ftop[f]=mpx->ftop[ff];
+}
+
+@ The string |cur_name| is supposed to be set to the external name of the
+\.{VF} file for the current font.
+@^system dependencies@>
+
+@<Move the \.{VF} file name into the |cur_name| string@>=
+mpx->cur_name = xstrdup (mpx->font_name[f])
+
+@ @<Make sure the checksum in the font file matches the one given in the...@>=
+{
+ if ( (mpx->font_check_sum[f]!=0)&&(mpx->tfm_check_sum!=0)&&@|
+ (mpx->font_check_sum[f]!=mpx->tfm_check_sum) ) {
+ font_warn("Checksum mismatch for ",f);
+@.Checksum mismatch@>
+ }
+}
+
+@* Low level output routines.
+
+One of the basic output operations is to write a \MP\ string expression for
+a sequence of characters to be typeset. The main difficulties are that such
+strings can contain arbitrary eight-bit bytes and there is no fixed limit on
+the length of the string that needs to be produced. In extreme cases this
+can lead to expressions such as
+$$\vcenter{
+ \hbox{\.{char7\&char15\&char31\&"?FWayzz"}}
+ \hbox{\.{\&"zzaF"\&char15\&char3\&char31}}
+ \hbox{\.{\&"Nxzzzzzzzwvtsqo"}}}
+$$
+
+@ A global variable |state| keeps track of the output process.
+When |state=normal| we have begun a quoted string and the next character
+should be a printable character or a closing quote. When |state=special|
+the last thing printed was a ``\.{char}'' construction or a closing quote
+and an ampersand should come next. The starting condition |state=initial|
+is a lot like |state=special|, except no ampersand is required.
+
+@d special 0 /* the |state| after printing a ``\.{char}'' expression */
+@d normal 1 /* the |state| value in a quoted string */
+@d initial 2 /* initial |state| */
+
+@<Glob...@>=
+int state; /* controls the process of printing a string */
+int print_col; /* there are at most this many characters on the current line */
+
+@ @<Set initial values@>=
+mpx->state = initial;
+mpx->print_col = 0; /* there are at most this many characters on the current line */
+
+@ To print a string on the \.{MPX} file, initialize |print_col|, ensure that
+|state=initial|, and pass the characters one-at-a-time to |print_char|.
+
+@<Declare subroutines for printing strings@>=
+static void mpx_print_char (MPX mpx, unsigned char c) {
+ web_integer l; /* number of characters to print |c| or the \.{char} expression */
+ if ( printable(c) ) l=1;
+ else if ( c<10 ) l=5;
+ else if ( c<100 ) l=6;
+ else l=7;
+ if ( mpx->print_col+l>line_length-2 ) {
+ if ( mpx->state==normal ) {
+ fprintf(mpx->mpxfile,"\""); mpx->state=special;
+ }
+ fprintf(mpx->mpxfile,"\n");
+ mpx->print_col=0;
+ }
+ @<Print |c| and update |state| and |print_col|@>;
+}
+
+@ @<Print |c| and update |state| and |print_col|@>=
+if ( mpx->state==normal ) {
+ if ( printable(c) ) {
+ fprintf(mpx->mpxfile,"%c",xchr(c));
+ } else {
+ fprintf(mpx->mpxfile,"\"&char%d",c);
+ mpx->print_col +=2;
+ }
+} else {
+ if ( mpx->state==special ) {
+ fprintf(mpx->mpxfile,"&");
+ incr(mpx->print_col);
+ }
+ if ( printable(c) ) {
+ fprintf(mpx->mpxfile,"\"%c",xchr(c));
+ incr(mpx->print_col);
+ } else {
+ fprintf(mpx->mpxfile,"char%d",c);
+ }
+}
+mpx->print_col += l;
+if ( printable(c) )
+ mpx->state=normal;
+else
+ mpx->state=special
+
+@ The |end_char_string| procedure gets the string ended properly and ensures
+that there is room for |l| more characters on the output line.
+
+@<Declare subroutines for printing strings@>=
+static void mpx_end_char_string (MPX mpx,web_integer l) {
+ while ( mpx->state>special ){
+ fprintf(mpx->mpxfile,"\"");
+ incr(mpx->print_col);
+ decr(mpx->state);
+ }
+ if ( mpx->print_col+l>line_length ) {
+ fprintf(mpx->mpxfile,"\n "); mpx->print_col=0;
+ }
+ mpx->state=initial; /* get ready to print the next string */
+}
+
+@ Since |end_char_string| resets |state:=initial|, all we have to do is set
+|state:=initial| once at the beginning.
+
+@<Set init...@>=
+mpx->state=initial;
+
+@ Characters and rules are positioned according to global variables |h| and~|v|
+as will be explained later. We also need scale factors that convert quantities
+to the right units when they are printed in the \.{MPX} file.
+
+Even though all variable names in the \MP\ output are made local via \.{save}
+commands, it is still desirable to preceed them with underscores. This makes
+the output more likely to work when used in a macro definition, since the
+generated variables names must not collide with formal parameters in such
+cases.
+
+@<Glob...@>=
+web_integer h;
+web_integer v; /* the current position in \.{DVI} units */
+double conv; /* converts \.{DVI} units to \MP\ points */
+double mag; /* magnification factor times 1000 */
+
+@ @c @<Declare a procedure called |finish_last_char|@>@;
+static void mpx_do_set_char (MPX mpx,web_integer f, web_integer c) {
+ if ( (c<mpx->font_bc[f])||(c>mpx->font_ec[f]) )
+ mpx_abort(mpx,"attempt to typeset invalid character %d",c);
+@.attempt to typeset...@>
+ if ((mpx->h!=mpx->str_h2)||(mpx->v!=mpx->str_v)||
+ (f!=mpx->str_f)||(mpx->dvi_scale!=mpx->str_scale) ) {
+ if ( mpx->str_f>=0 ) {
+ mpx_finish_last_char(mpx);
+ } else if ( ! mpx->fonts_used ) {
+ @<Prepare to output the first character on a page@>;
+ }
+ if ( ! mpx->font_used[f] )
+ @<Prepare to use font |f| for the first time on a page@>;
+ fprintf(mpx->mpxfile,"_s("); mpx->print_col=3;@/
+ mpx->str_scale=mpx->dvi_scale; mpx->str_f=f;
+ mpx->str_v=mpx->v; mpx->str_h1=mpx->h;
+ }
+ mpx_print_char(mpx, (unsigned char)c);
+ mpx->str_h2=(web_integer)(mpx->h+@<Width of character |c| in font |f|@>);
+}
+
+@ @<Glob...@>=
+boolean font_used[(max_fonts+1)]; /* has this font been used on this page? */
+boolean fonts_used; /* has any font been used on this page? */
+boolean rules_used; /* has any rules been set on this page? */
+web_integer str_h1;
+web_integer str_v; /* starting position for current output string */
+web_integer str_h2; /* where the current output string ends */
+web_integer str_f; /* internal font number for the current output string */
+double str_scale; /* value of |dvi_scale| for the current output string */
+
+
+@ Before using any fonts we need to define a MetaPost macro for
+typesetting character strings. The |font_used| array is not
+initialized until it is actually time to output a character.
+
+@<Declarations@>=
+static void mpx_prepare_font_use(MPX mpx);
+
+@ @c
+static void mpx_prepare_font_use(MPX mpx) {
+ unsigned k;
+ for (k=0; k<mpx->nfonts;k++ )
+ mpx->font_used[k]=false;
+ mpx->fonts_used=true;
+ fprintf(mpx->mpxfile,"string _n[];\n");
+ fprintf(mpx->mpxfile,"vardef _s(expr _t,_f,_m,_x,_y)(text _c)=\n");
+ fprintf(mpx->mpxfile,
+ " addto _p also _t infont _f scaled _m shifted (_x,_y) _c; enddef;\n");
+}
+
+@ @<Prepare to output the first character on a page@>=
+mpx_prepare_font_use(mpx)
+
+
+@ @<Do any other initialization required for the new font |f|@>=
+mpx->font_used[f]=false;
+
+@ Do what is necessary when the font with internal number f is used for the
+first time on a page.
+
+@<Declarations@>=
+static void mpx_first_use(MPX mpx, int f) ;
+
+@ @c
+static void mpx_first_use(MPX mpx, int f) {
+ mpx->font_used[f]=true;
+ fprintf(mpx->mpxfile,"_n%d=",f);
+ mpx->print_col=6;
+ mpx_print_font(mpx, f);
+ mpx_end_char_string(mpx, 1);
+ fprintf(mpx->mpxfile,";\n");
+}
+
+@ @<Prepare to use font |f| for the first time on a page@>=
+mpx_first_use(mpx,f);
+
+@ We maintain the invariant that |str_f=-1| when there is no output string
+under construction.
+
+@<Declare a procedure called |finish_last_char|@>=
+static void mpx_finish_last_char (MPX mpx) {
+ double m,x,y;
+ /* font scale factor and \MP\ coordinates of reference point */
+ if ( mpx->str_f>=0 ) {
+ if (mpx->mode==mpx_tex_mode) {
+ m=mpx->str_scale*mpx->font_scaled_size[mpx->str_f]*
+ mpx->mag/mpx->font_design_size[mpx->str_f];
+ x=mpx->conv*mpx->str_h1;
+ y=mpx->conv*(-mpx->str_v);
+ if ( (fabs(x)>=4096.0)||(fabs(y)>=4096.0)||(m>=4096.0)||(m<0) ) {
+ mpx_warn(mpx,"text is out of range");
+ mpx_end_char_string(mpx, 60);
+ } else {
+ mpx_end_char_string(mpx, 40);
+ }
+ fprintf(mpx->mpxfile,",_n%d,%1.5f,%1.4f,%1.4f,",mpx->str_f,m,x,y);
+ @<Print a \.{withcolor} specifier if appropriate@>@/
+ fprintf(mpx->mpxfile,");\n");
+ } else {
+ m = mpx->str_size / mpx->font_design_size[mpx->str_f];
+ x = mpx->dmp_str_h1 * mpx->unit;
+ y = YCORR - mpx->dmp_str_v * mpx->unit;
+ if (fabs(x) >= 4096.0 || fabs(y) >= 4096.0 || m >= 4096.0 || m < 0) {
+ mpx_warn(mpx,"text out of range ignored");
+ mpx_end_char_string(mpx,67);
+ } else {
+ mpx_end_char_string(mpx,47);
+ }
+ fprintf(mpx->mpxfile, ")infont n%d", mpx->font_num[mpx->str_f]);
+ mpx_slant_and_ht(mpx);
+ fprintf(mpx->mpxfile, ",%.5f,%.4f,%.4f);\n", (m*1.00375), x, y);
+ }
+ mpx->str_f=-1;
+ }
+}
+
+@ Setting rules is fairly simple.
+
+@c
+static void mpx_do_set_rule (MPX mpx,web_integer ht, web_integer wd) {
+ double xx1,yy1,xx2,yy2,ww;
+ /* \MP\ coordinates of lower-left and upper-right corners */
+ if ( wd==1 ) {
+ @<Handle a special rule that determines the box size@>
+ } else if ( (ht>0)||(wd>0) ) {
+ if ( mpx->str_f>=0 )
+ mpx_finish_last_char(mpx);
+ if ( ! mpx->rules_used ) {
+ mpx->rules_used=true;
+ fprintf(mpx->mpxfile,
+ "interim linecap:=0;\n"
+ "vardef _r(expr _a,_w)(text _t) =\n"
+ " addto _p doublepath _a withpen pencircle scaled _w _t enddef;");
+ }
+ @<Make |(xx1,yy1)| and |(xx2,yy2)| then ends of the desired penstroke
+ and |ww| the desired stroke width@>;
+ if ( (fabs(xx1)>=4096.0)||(fabs(yy1)>=4096.0)||@|
+ (fabs(xx2)>=4096.0)||(fabs(yy2)>=4096.0)||(ww>=4096.0) )
+ mpx_warn(mpx,"hrule or vrule is out of range");
+ fprintf(mpx->mpxfile,"_r((%1.4f,%1.4f)..(%1.4f,%1.4f), %1.4f,",xx1,yy1,xx2,yy2,ww);
+ @<Print a \.{withcolor} specifier if appropriate@>@/
+ fprintf(mpx->mpxfile,");\n");
+ }
+}
+
+@ @<Make |(xx1,yy1)| and |(xx2,yy2)| then ends of the desired penstroke...@>=
+xx1=mpx->conv*mpx->h;
+yy1=mpx->conv*(-mpx->v);
+if ( wd>ht ){
+ xx2=xx1+mpx->conv*wd;
+ ww=mpx->conv*ht;
+ yy1=yy1+0.5*ww;
+ yy2=yy1;
+} else {
+ yy2=yy1+mpx->conv*ht;
+ ww=mpx->conv*wd;
+ xx1=xx1+0.5*ww;
+ xx2=xx1;
+}
+
+@ Rules of width one dvi unit are not typeset since \.{MPtoTeX} adds an
+extraneous rule of this width in order to allow \.{DVItoMP} to deduce the
+dimensions of the boxes it ships out. The box width is the left edge of the
+last such rule; the height and depth are at the top and bottom of the rule.
+There should be only one special rule per picture but there could be more if
+the user tries to typeset his own one-dvi-unit rules. In this case the
+dimension-determining rule is the last one in the picture.
+
+@<Handle a special rule that determines the box size@>=
+{
+ mpx->pic_wd=mpx->h; mpx->pic_dp=mpx->v; mpx->pic_ht=ht-mpx->v;
+}
+
+@ @<Glob...@>=
+web_integer pic_dp; web_integer pic_ht; web_integer pic_wd; /* picture dimensions from special rule */
+
+@ The following initialization and clean-up is required. We do a little more
+initialization than is absolutely necessary since some compilers might complain
+if the variables are uninitialized when |do_set_char| tests them.
+
+@c
+static void mpx_start_picture (MPX mpx) {
+ mpx->fonts_used=false;
+ mpx->rules_used=false;
+ mpx->graphics_used=false;
+ mpx->str_f=-1;
+ mpx->str_v=0;
+ mpx->str_h2=0;
+ mpx->str_scale=1.0; /* values don't matter */
+ mpx->dmp_str_v = 0.0;
+ mpx->dmp_str_h2 = 0.0;
+ mpx->str_size = 0.0;
+ fprintf(mpx->mpxfile,
+ "begingroup save %s_p,_r,_s,_n; picture _p; _p=nullpicture;\n",
+ (mpx->mode == mpx_tex_mode ? "" : "_C,_D,"));
+}
+
+static void mpx_stop_picture (MPX mpx) {
+ double w,h,dd; /* width, height, negative depth in PostScript points */
+ if ( mpx->str_f>=0 )
+ mpx_finish_last_char(mpx);
+ if (mpx->mode==mpx_tex_mode) {
+ @<Print a \&{setbounds} command based on picture dimensions@>;
+ }
+ fprintf(mpx->mpxfile,"_p endgroup\n");
+}
+
+@ @<Print a \&{setbounds} command based on picture dimensions@>=
+dd=-mpx->pic_dp*mpx->conv;
+w=mpx->conv*mpx->pic_wd;
+h=mpx->conv*mpx->pic_ht;
+fprintf(mpx->mpxfile,
+ "setbounds _p to (0,%1.4f)--(%1.4f,%1.4f)--\n"
+ " (%1.4f,%1.4f)--(0,%1.4f)--cycle;\n",dd,w,dd,w,h,h)
+
+@* Translation to symbolic form.
+
+The main work of \.{DVItoMP} is accomplished by the |do_dvi_commands|
+procedure, which produces the output for an entire page, assuming that the
+|bop| command for that page has already been processed. This procedure is
+essentially an interpretive routine that reads and acts on the \.{DVI}
+commands. It is also capable of executing the typesetting commands for
+a character in a virtual font.
+
+@ The definition of \.{DVI} files refers to six registers,
+$(h,v,w,x,y,z)$, which hold web_integer values in \.{DVI} units.
+These units come directly from the input file except they need to be
+rescaled when typesetting characters from a virtual font.
+The stack of $(h,v,w,x,y,z)$ values is represented by six arrays
+called |hstack|, \dots, |zstack|.
+
+@<Glob...@>=
+web_integer w;web_integer x;web_integer y;web_integer z;
+ /* current state values (|h| and |v| have already been declared) */
+web_integer hstack[(stack_size+1)];
+web_integer vstack[(stack_size+1)];
+web_integer wstack[(stack_size+1)];
+web_integer xstack[(stack_size+1)];
+web_integer ystack[(stack_size+1)];
+web_integer zstack[(stack_size+1)]; /* pushed down values in \.{DVI} units */
+web_integer stk_siz; /* the current stack size */
+double dvi_scale; /* converts units of current input source to \.{DVI} units */
+
+@ @<Do initialization required before starting a new page@>=
+mpx->dvi_scale=1.0;
+mpx->stk_siz=0;
+mpx->h=0; mpx->v=0;
+mpx->Xslant = 0.0; mpx->Xheight = 0.0
+
+@ Next, we need procedures to handle |push| and |pop| commands.
+
+@c @<Declare procedures to handle color commands@>
+static void mpx_do_push (MPX mpx) {
+ if ( mpx->stk_siz==stack_size )
+ mpx_abort(mpx,"DVItoMP capacity exceeded (stack size=%d)",stack_size);
+@.DVItoMP capacity exceeded...@>
+ mpx->hstack[mpx->stk_siz]=mpx->h;
+ mpx->vstack[mpx->stk_siz]=mpx->v; mpx->wstack[mpx->stk_siz]=mpx->w;
+ mpx->xstack[mpx->stk_siz]=mpx->x;
+ mpx->ystack[mpx->stk_siz]=mpx->y; mpx->zstack[mpx->stk_siz]=mpx->z;
+ incr(mpx->stk_siz);
+}
+
+static void mpx_do_pop (MPX mpx) {
+ if ( mpx->stk_siz==0 )
+ bad_dvi("attempt to pop empty stack");
+ else {
+ decr(mpx->stk_siz);
+ mpx->h=mpx->hstack[mpx->stk_siz];
+ mpx->v=mpx->vstack[mpx->stk_siz]; mpx->w=mpx->wstack[mpx->stk_siz];
+ mpx->x=mpx->xstack[mpx->stk_siz];
+ mpx->y=mpx->ystack[mpx->stk_siz]; mpx->z=mpx->zstack[mpx->stk_siz];
+ }
+}
+
+@ The |set_virtual_char| procedure is mutually recursive with
+|do_dvi_commands|. This is really a supervisory
+@^recursion@>
+procedure that calls |do_set_char| or adjusts the input source to read
+typesetting commands for a character in a virtual font.
+
+@c
+static void mpx_do_dvi_commands (MPX mpx);
+static void mpx_set_virtual_char (MPX mpx,web_integer f, web_integer c) {
+ double old_scale; /* original value of |dvi_scale| */
+ unsigned old_buf_ptr; /* original value of the input pointer |buf_ptr| */
+ unsigned old_fbase,old_ftop; /* originally applicable part of the |font_num| table */
+ if ( mpx->fbase[f]==0 )
+ mpx_do_set_char(mpx, f,c);
+ else {
+ old_fbase=mpx->cur_fbase; old_ftop=mpx->cur_ftop;
+ mpx->cur_fbase=(unsigned int)mpx->fbase[f];
+ mpx->cur_ftop=(unsigned int)mpx->ftop[f];
+ old_scale=mpx->dvi_scale;
+ mpx->dvi_scale=mpx->dvi_scale*mpx->font_scaled_size[f];
+ old_buf_ptr=mpx->buf_ptr;
+ mpx->buf_ptr=(unsigned int)start_cmd(f,c);
+ mpx_do_push(mpx);
+ mpx_do_dvi_commands(mpx);
+ mpx_do_pop(mpx);@/
+ mpx->buf_ptr=old_buf_ptr;
+ mpx->dvi_scale=old_scale;
+ mpx->cur_fbase=old_fbase;
+ mpx->cur_ftop=old_ftop;
+ }
+}
+
+@ Before we get into the details of |do_dvi_commands|, it is convenient to
+consider a simpler routine that computes the first parameter of each
+opcode.
+
+@d four_cases(A) (A): case (A)+1: case (A)+2: case (A)+3
+@d eight_cases(A) four_cases((A)): case four_cases((A)+4)
+@d sixteen_cases(A) eight_cases((A)): case eight_cases((A)+8)
+@d thirty_two_cases(A) sixteen_cases((A)): case sixteen_cases((A)+16)
+@d sixty_four_cases(A) thirty_two_cases((A)): case thirty_two_cases((A)+32)
+
+@<Declare a function called |first_par|@>=
+static web_integer mpx_first_par (MPX mpx, unsigned int o) {
+ switch (o) {
+ case sixty_four_cases(set_char_0):
+ case sixty_four_cases(set_char_0+64):
+ return (web_integer)(o-set_char_0);
+ break;
+ case set1: case put1: case fnt1: case xxx1: case fnt_def1:
+ return mpx_get_byte(mpx);
+ break;
+ case set1+1: case put1+1: case fnt1+1: case xxx1+1: case fnt_def1+1:
+ return mpx_get_two_bytes(mpx);
+ break;
+ case set1+2: case put1+2: case fnt1+2: case xxx1+2: case fnt_def1+2:
+ return mpx_get_three_bytes(mpx);
+ break;
+ case right1: case w1: case x1: case down1: case y1: case z1:
+ return mpx_signed_byte(mpx);
+ break;
+ case right1+1: case w1+1: case x1+1: case down1+1: case y1+1: case z1+1:
+ return mpx_signed_pair(mpx);
+ break;
+ case right1+2: case w1+2: case x1+2: case down1+2: case y1+2: case z1+2:
+ return mpx_signed_trio(mpx);
+ break;
+ case set1+3: case set_rule: case put1+3: case put_rule:
+ case right1+3: case w1+3: case x1+3: case down1+3: case y1+3: case z1+3:
+ case fnt1+3: case xxx1+3: case fnt_def1+3:
+ return mpx_signed_quad(mpx);
+ break;
+ case nop: case bop: case eop: case push: case pop: case pre: case post:
+ case post_post: case undefined_commands:
+ return 0;
+ break;
+ case w0: return mpx->w; break;
+ case x0: return mpx->x; break;
+ case y0: return mpx->y; break;
+ case z0: return mpx->z; break;
+ case sixty_four_cases(fnt_num_0):
+ return (web_integer)(o-fnt_num_0);
+ break;
+ }
+ return 0; /* compiler warning */
+}
+
+@ Here is the |do_dvi_commands| procedure.
+
+@c
+static void mpx_do_dvi_commands (MPX mpx) {
+ unsigned int o; /* operation code of the current command */
+ web_integer p,q; /* parameters of the current command */
+ web_integer cur_font; /* current internal font number */
+ if ( (mpx->cur_fbase<mpx->cur_ftop) && (mpx->buf_ptr<virtual_space) )
+ cur_font=mpx_select_font(mpx, mpx->font_num[mpx->cur_ftop-1]); /* select first local font */
+ else
+ cur_font=max_fnums+1; /* current font is undefined */
+ mpx->w=0; mpx->x=0; mpx->y=0; mpx->z=0; /* initialize the state variables */
+ while ( true ) {
+ @<Translate the next command in the \.{DVI} file; |return| if it was |eop|@>;
+ }
+}
+
+@ The multiway switch in |first_par|, above, was organized by the length
+of each command; the one in |do_dvi_commands| is organized by the semantics.
+
+@ @<Translate the next command...@>=
+{
+ o=(unsigned int)mpx_get_byte(mpx);
+ p=mpx_first_par(mpx, o);
+ if ( feof(mpx->dvi_file) )
+ bad_dvi("the DVI file ended prematurely");
+@.the DVI file ended prematurely@>
+ if ( o<set1+4 ) { /* |set_char_0| through |set_char_127|, |set1| through |set4| */
+ if ( cur_font>max_fnums ) {
+ if ( mpx->vf_reading )
+ mpx_abort(mpx,"no font selected for character %d in virtual font", p);
+ else
+ bad_dvi_two("no font selected for character %d",p);
+ }
+@.no font selected@>
+ mpx_set_virtual_char(mpx, cur_font,p);
+ mpx->h += @<Width of character |p| in font |cur_font|@>;
+ } else {
+ switch(o) {
+ case four_cases(put1):
+ mpx_set_virtual_char(mpx, cur_font, p);
+ break;
+ case set_rule:
+ q=(web_integer)trunc(mpx_signed_quad(mpx)*mpx->dvi_scale);
+ mpx_do_set_rule(mpx, (web_integer)trunc(p*mpx->dvi_scale),q);
+ mpx->h += q;
+ break;
+ case put_rule:
+ q=(web_integer)trunc(mpx_signed_quad(mpx)*mpx->dvi_scale);
+ mpx_do_set_rule(mpx, (web_integer)trunc(p*mpx->dvi_scale),q);
+ break;
+ @<Additional cases for translating \.{DVI} command |o| with
+ first parameter |p|@>@;
+ case undefined_commands:
+ bad_dvi_two("undefined command %d",o);
+@.undefined command@>
+ break;
+ } /* all cases have been enumerated */
+ }
+}
+
+@ @<Additional cases for translating \.{DVI} command |o|...@>=
+case four_cases(xxx1):
+ mpx_do_xxx(mpx, p);
+ break;
+case pre: case post: case post_post:
+ bad_dvi("preamble or postamble within a page!");
+@.preamble or postamble within a page@>
+ break;
+
+@ @<Additional cases for translating \.{DVI} command |o|...@>=
+case nop:
+ break;
+case bop:
+ bad_dvi("bop occurred before eop");
+@.bop occurred before eop@>
+ break;
+case eop:
+ return;
+ break;
+case push:
+ mpx_do_push(mpx);
+ break;
+case pop:
+ mpx_do_pop(mpx);
+ break;
+
+@ @<Additional cases for translating \.{DVI} command |o|...@>=
+case four_cases(right1):
+ mpx->h += trunc(p*mpx->dvi_scale);
+ break;
+case w0: case four_cases(w1):
+ mpx->w = (web_integer)trunc(p*mpx->dvi_scale); mpx->h += mpx->w;
+ break;
+case x0: case four_cases(x1):
+ mpx->x = (web_integer)trunc(p*mpx->dvi_scale); mpx->h += mpx->x;
+ break;
+case four_cases(down1):
+ mpx->v += trunc(p*mpx->dvi_scale);
+ break;
+case y0: case four_cases(y1):
+ mpx->y = (web_integer)trunc(p*mpx->dvi_scale); mpx->v += mpx->y;
+ break;
+case z0: case four_cases(z1):
+ mpx->z = (web_integer)trunc(p*mpx->dvi_scale); mpx->v += mpx->z;
+ break;
+
+@ @<Additional cases for translating \.{DVI} command |o|...@>=
+case sixty_four_cases(fnt_num_0): case four_cases(fnt1):
+ cur_font = mpx_select_font(mpx, p);
+ break;
+case four_cases(fnt_def1):
+ mpx_define_font(mpx, p);
+ break;
+
+@* The main program.
+Now we are ready to put it all together. This is where \.{DVItoMP} starts,
+and where it ends.
+
+@c
+static int mpx_dvitomp (MPX mpx, char *dviname) {
+ int k;
+ mpx->dviname = dviname;
+ mpx_open_dvi_file(mpx);
+ @<Process the preamble@>;
+ mpx_open_mpxfile(mpx);
+ if (mpx->banner!=NULL)
+ fprintf (mpx->mpxfile,"%s\n",mpx->banner);
+ while ( true ) {
+ @<Advance to the next |bop| command@>;
+ for (k=0;k<=10;k++)
+ (void)mpx_signed_quad(mpx);
+ @<Do initialization required before starting a new page@>;
+ mpx_start_picture(mpx);
+ mpx_do_dvi_commands(mpx);
+ if ( mpx->stk_siz!=0 )
+ bad_dvi("stack not empty at end of page");
+@.stack not empty...@>
+ mpx_stop_picture(mpx);
+ fprintf(mpx->mpxfile,"mpxbreak\n");
+ }
+ if(mpx->dvi_file)
+ mpx_fclose(mpx,mpx->dvi_file);
+ if ( mpx->history<=mpx_cksum_trouble )
+ return 0;
+ else
+ return mpx->history;
+}
+
+@ The main program needs a few global variables in order to do its work.
+
+@<Glob...@>=
+web_integer k;web_integer p; /* general purpose registers */
+web_integer numerator;web_integer denominator; /* stated conversion ratio */
+
+@ @<Process the preamble@>=
+{
+ int p;
+ p=mpx_get_byte(mpx); /* fetch the first byte */
+ if ( p!=pre )
+ bad_dvi("First byte isn""t start of preamble!");
+@.First byte isn't...@>
+ p=mpx_get_byte(mpx); /* fetch the identification byte */
+ if ( p!=id_byte )
+ mpx_warn(mpx,"identification in byte 1 should be %d!", id_byte);
+@.identification...should be n@>
+ @<Compute the conversion factor@>;
+ p=mpx_get_byte(mpx); /* fetch the length of the introductory comment */
+ while (p>0 ){
+ decr(p);
+ (void)mpx_get_byte(mpx);
+ }
+}
+
+@ The conversion factor |conv| is figured as follows: There are exactly
+|n/d| decimicrons per \.{DVI} unit, and 254000 decimicrons per inch,
+and |resolution| pixels per inch. Then we have to adjust this
+by the stated amount of magnification. No such adjustment is needed for
+|dvi_per_fix| since it is used to convert design sizes.
+
+@<Compute the conversion factor@>=
+mpx->numerator=mpx_signed_quad(mpx); mpx->denominator=mpx_signed_quad(mpx);
+if ( (mpx->numerator<=0)||(mpx->denominator<=0) )
+ bad_dvi("bad scale ratio in preamble");
+@.bad scale ratio@>
+mpx->mag=mpx_signed_quad(mpx)/1000.0;
+if ( mpx->mag<=0.0 )
+ bad_dvi("magnification isn't positive");
+@.magnification isn't positive@>
+mpx->conv=(mpx->numerator/254000.0)*(72.0/mpx->denominator)*mpx->mag;
+mpx->dvi_per_fix=(254000.0/mpx->numerator)*(mpx->denominator/72.27)/1048576.0;
+
+@ @<Advance to the next |bop| command@>=
+do {
+ int p;
+ k=mpx_get_byte(mpx);
+ if ( (k>=fnt_def1)&&(k<fnt_def1+4) ){
+ p=mpx_first_par(mpx, (unsigned int)k);
+ mpx_define_font(mpx, p); k=nop;
+ }
+} while (k==nop);
+if ( k==post )
+ break;
+if ( k!=bop )
+ bad_dvi("missing bop");
+@.missing bop@>
+
+
+@ Global filenames.
+
+@<Global...@>=
+char *dviname;
+
+@* Color support.
+These changes support \.{dvips}-style ``\.{color push NAME}'' and
+``\.{color pop}'' specials. We store a list of named colors, sorted by
+name, and decorate the relevant drawing commands with ``\.{withcolor
+(r,g,b)}'' specifiers while a color is defined.
+
+@ A constant bounding the size of the named-color array.
+
+@d max_named_colors 100 /* maximum number of distinct named colors */
+
+@ Then we declare a record for color types.
+
+@<Types...@>=
+typedef struct named_color_record {
+ char *name; /* color name */
+ char *value; /* text to pass to MetaPost */
+} named_color_record;
+
+@ Declare the named-color array itself.
+
+@<Globals@>=
+named_color_record named_colors[(max_named_colors+1)];
+ /* stores information about named colors, in sorted order by name */
+web_integer num_named_colors; /* number of elements of |named_colors| that are valid */
+
+@ This function, used only during initialization, defines a named color.
+
+@c
+static void mpx_def_named_color (MPX mpx, char *n, char *v) {
+ mpx->num_named_colors++;
+ assert(mpx->num_named_colors<max_named_colors);
+ mpx->named_colors[mpx->num_named_colors].name = n;
+ mpx->named_colors[mpx->num_named_colors].value = v;
+}
+
+@ @<Declarations@>=
+static void mpx_def_named_color (MPX mpx, char *n, char *v);
+
+@ During the initialization phase, we define values for all the named
+colors defined in \.{colordvi.tex}. CMYK-to-RGB conversion by GhostScript.
+
+This list has to be sorted alphabetically!
+
+@<Set initial values@>=
+mpx->num_named_colors = 0;
+mpx_def_named_color(mpx, "Apricot", "(1.0, 0.680006, 0.480006)");
+mpx_def_named_color(mpx, "Aquamarine", "(0.180006, 1.0, 0.7)");
+mpx_def_named_color(mpx, "Bittersweet", "(0.760012, 0.0100122, 0.0)");
+mpx_def_named_color(mpx, "Black", "(0.0, 0.0, 0.0)");
+mpx_def_named_color(mpx, "Blue", "(0.0, 0.0, 1.0)");
+mpx_def_named_color(mpx, "BlueGreen", "(0.15, 1.0, 0.669994)");
+mpx_def_named_color(mpx, "BlueViolet", "(0.1, 0.05, 0.960012)");
+mpx_def_named_color(mpx, "BrickRed", "(0.719994, 0.0, 0.0)");
+mpx_def_named_color(mpx, "Brown", "(0.4, 0.0, 0.0)");
+mpx_def_named_color(mpx, "BurntOrange", "(1.0, 0.489988, 0.0)");
+mpx_def_named_color(mpx, "CadetBlue", "(0.380006, 0.430006, 0.769994)");
+mpx_def_named_color(mpx, "CarnationPink", "(1.0, 0.369994, 1.0)");
+mpx_def_named_color(mpx, "Cerulean", "(0.0600122, 0.889988, 1.0)");
+mpx_def_named_color(mpx, "CornflowerBlue", "(0.35, 0.869994, 1.0)");
+mpx_def_named_color(mpx, "Cyan", "(0.0, 1.0, 1.0)");
+mpx_def_named_color(mpx, "Dandelion", "(1.0, 0.710012, 0.160012)");
+mpx_def_named_color(mpx, "DarkOrchid", "(0.6, 0.2, 0.8)");
+mpx_def_named_color(mpx, "Emerald", "(0.0, 1.0, 0.5)");
+mpx_def_named_color(mpx, "ForestGreen", "(0.0, 0.880006, 0.0)");
+mpx_def_named_color(mpx, "Fuchsia", "(0.45, 0.00998169, 0.919994)");
+mpx_def_named_color(mpx, "Goldenrod", "(1.0, 0.9, 0.160012)");
+mpx_def_named_color(mpx, "Gray", "(0.5, 0.5, 0.5)");
+mpx_def_named_color(mpx, "Green", "(0.0, 1.0, 0.0)");
+mpx_def_named_color(mpx, "GreenYellow", "(0.85, 1.0, 0.310012)");
+mpx_def_named_color(mpx, "JungleGreen", "(0.0100122, 1.0, 0.480006)");
+mpx_def_named_color(mpx, "Lavender", "(1.0, 0.519994, 1.0)");
+mpx_def_named_color(mpx, "LimeGreen", "(0.5, 1.0, 0.0)");
+mpx_def_named_color(mpx, "Magenta", "(1.0, 0.0, 1.0)");
+mpx_def_named_color(mpx, "Mahogany", "(0.65, 0.0, 0.0)");
+mpx_def_named_color(mpx, "Maroon", "(0.680006, 0.0, 0.0)");
+mpx_def_named_color(mpx, "Melon", "(1.0, 0.539988, 0.5)");
+mpx_def_named_color(mpx, "MidnightBlue", "(0.0, 0.439988, 0.569994)");
+mpx_def_named_color(mpx, "Mulberry", "(0.640018, 0.0800061, 0.980006)");
+mpx_def_named_color(mpx, "NavyBlue", "(0.0600122, 0.460012, 1.0)");
+mpx_def_named_color(mpx, "OliveGreen", "(0.0, 0.6, 0.0)");
+mpx_def_named_color(mpx, "Orange", "(1.0, 0.389988, 0.130006)");
+mpx_def_named_color(mpx, "OrangeRed", "(1.0, 0.0, 0.5)");
+mpx_def_named_color(mpx, "Orchid", "(0.680006, 0.360012, 1.0)");
+mpx_def_named_color(mpx, "Peach", "(1.0, 0.5, 0.3)");
+mpx_def_named_color(mpx, "Periwinkle", "(0.430006, 0.45, 1.0)");
+mpx_def_named_color(mpx, "PineGreen", "(0.0, 0.75, 0.160012)");
+mpx_def_named_color(mpx, "Plum", "(0.5, 0.0, 1.0)");
+mpx_def_named_color(mpx, "ProcessBlue", "(0.0399878, 1.0, 1.0)");
+mpx_def_named_color(mpx, "Purple", "(0.55, 0.139988, 1.0)");
+mpx_def_named_color(mpx, "RawSienna", "(0.55, 0.0, 0.0)");
+mpx_def_named_color(mpx, "Red", "(1.0, 0.0, 0.0)");
+mpx_def_named_color(mpx, "RedOrange", "(1.0, 0.230006, 0.130006)");
+mpx_def_named_color(mpx, "RedViolet", "(0.590018, 0.0, 0.660012)");
+mpx_def_named_color(mpx, "Rhodamine", "(1.0, 0.180006, 1.0)");
+mpx_def_named_color(mpx, "RoyalBlue", "(0.0, 0.5, 1.0)");
+mpx_def_named_color(mpx, "RoyalPurple", "(0.25, 0.1, 1.0)");
+mpx_def_named_color(mpx, "RubineRed", "(1.0, 0.0, 0.869994)");
+mpx_def_named_color(mpx, "Salmon", "(1.0, 0.469994, 0.619994)");
+mpx_def_named_color(mpx, "SeaGreen", "(0.310012, 1.0, 0.5)");
+mpx_def_named_color(mpx, "Sepia", "(0.3, 0.0, 0.0)");
+mpx_def_named_color(mpx, "SkyBlue", "(0.380006, 1.0, 0.880006)");
+mpx_def_named_color(mpx, "SpringGreen", "(0.739988, 1.0, 0.239988)");
+mpx_def_named_color(mpx, "Tan", "(0.860012, 0.580006, 0.439988)");
+mpx_def_named_color(mpx, "TealBlue", "(0.119994, 0.980006, 0.640018)");
+mpx_def_named_color(mpx, "Thistle", "(0.880006, 0.410012, 1.0)");
+mpx_def_named_color(mpx, "Turquoise", "(0.15, 1.0, 0.8)");
+mpx_def_named_color(mpx, "Violet", "(0.210012, 0.119994, 1.0)");
+mpx_def_named_color(mpx, "VioletRed", "(1.0, 0.189988, 1.0)");
+mpx_def_named_color(mpx, "White", "(1.0, 1.0, 1.0)");
+mpx_def_named_color(mpx, "WildStrawberry", "(1.0, 0.0399878, 0.610012)");
+mpx_def_named_color(mpx, "Yellow", "(1.0, 1.0, 0.0)");
+mpx_def_named_color(mpx, "YellowGreen", "(0.560012, 1.0, 0.260012)");
+mpx_def_named_color(mpx, "YellowOrange", "(1.0, 0.580006, 0.0)");
+
+@ Color commands get a separate warning procedure. |warn| sets |history :=
+mpx_warning_given|, which causes a nonzero exit status; but color errors are
+trivial and should leave the exit status zero.
+
+@d color_warn(A) mpx_warn(mpx,A)
+@d color_warn_two(A,B) mpx_warn(mpx,"%s%s",A,B)
+
+@ The |do_xxx| procedure handles DVI specials (defined with the |xxx1...xxx4| commands).
+
+@d XXX_BUF 256
+
+@<Declare procedures to handle color commands@>=
+static void mpx_do_xxx (MPX mpx, web_integer p)
+{
+ unsigned char buf[(XXX_BUF+1)]; /* FIXME: Fixed size buffer. */
+ web_integer l, r, m, k, len;
+ boolean found;
+ int bufsiz = XXX_BUF;
+ len = 0;
+ while ( ( p > 0) && (len < bufsiz) ) {
+ buf[len] = (unsigned char)mpx_get_byte(mpx);
+ decr(p); incr(len);
+ }
+ @<Check whether |buf| contains a color command; if not, |goto XXXX|@>
+ if ( p > 0 ) {
+ color_warn("long \"color\" special ignored");
+ goto XXXX;
+ }
+ if ( @<|buf| contains a color pop command@> ) {
+ @<Handle a color pop command@>
+ } else if ( @<|buf| contains a color push command@> ) {
+ @<Handle a color push command@>
+ } else {
+ color_warn("unknown \"color\" special ignored");
+ goto XXXX;
+ }
+XXXX:
+ for (k = 1;k<=p;k++) (void)mpx_get_byte(mpx);
+}
+
+@
+
+@<Check whether |buf| contains a color command; if not, |goto XXXX|@>=
+if ( (len <= 5)
+ || (buf[0] != 'c')
+ || (buf[1] != 'o')
+ || (buf[2] != 'l')
+ || (buf[3] != 'o')
+ || (buf[4] != 'r')
+ || (buf[5] != ' ')
+ ) goto XXXX;
+
+@ @<|buf| contains a color push command@>=
+(len >= 11) &&
+ (buf[6] == 'p') &&
+ (buf[7] == 'u') &&
+ (buf[8] == 's') &&
+ (buf[9] == 'h') &&
+ (buf[10] == ' ')
+
+@ @<|buf| contains a color pop command@>=
+(len == 9) &&
+(buf[6] == 'p') &&
+(buf[7] == 'o') &&
+(buf[8] == 'p')
+
+@ The \.{color push} and \.{pop} commands imply a color stack, so we need a
+global variable to hold that stack.
+
+@d max_color_stack_depth 10 /* maximum depth of saved color stack */
+
+@ Here's the actual stack variables.
+
+@<Globals@>=
+web_integer color_stack_depth; /* current depth of saved color stack */
+char *color_stack[(max_color_stack_depth+1)]; /* saved color stack */
+
+@ Initialize the stack to empty.
+
+@<Set initial values@>=
+mpx->color_stack_depth = 0;
+
+@ \.{color pop} just pops the stack.
+
+@<Handle a color pop command@>=
+mpx_finish_last_char(mpx);
+if (mpx->color_stack_depth > 0 ) {
+ free(mpx->color_stack[mpx->color_stack_depth]);
+ decr(mpx->color_stack_depth);
+} else {
+ color_warn("color stack underflow");
+}
+
+@ \.{color push} pushes a color onto the stack.
+
+@<Handle a color push command@>=
+mpx_finish_last_char(mpx);
+if ( mpx->color_stack_depth >= max_color_stack_depth )
+ mpx_abort(mpx,"color stack overflow");
+incr(mpx->color_stack_depth);
+/* I don't know how to do string operations in Pascal. */
+/* Skip over extra spaces after 'color push'. */
+l = 11;
+while ( (l < len - 1) && (buf[l] == ' ') ) incr(l);
+if ( @<|buf[l]| contains an rgb command@> ) {
+ @<Handle a color push rgb command@>
+} else if ( @<|buf[l]| contains a cmyk command@> ) {
+ @<Handle a color push cmyk command@>
+} else if ( @<|buf[l]| contains a gray command@> ) {
+ @<Handle a color push gray command@>
+} else {
+ @<Handle a named color push command@>
+}
+
+@ @<|buf[l]| contains an rgb command@>=
+(l + 4 < len)
+&& (buf[l] == 'r')
+&& (buf[l+1] == 'g')
+&& (buf[l+2] == 'b')
+&& (buf[l+3] == ' ')
+
+@ @<Handle a color push rgb command@>=
+l = l + 4;
+while ( (l < len) && (buf[l] == ' ') ) incr(l); /* Remove spaces at end of buf */
+while ( (len > l) && (buf[len - 1] == ' ') ) decr(len);
+mpx->color_stack[mpx->color_stack_depth]=xmalloc((size_t)(len-l+3),1);
+k = 0;
+@<Copy |buf[l]| to |color_stack[color_stack_depth][k]| in tuple form@>
+
+@ @<|buf[l]| contains a gray command@>=
+(l + 5 < len)
+&& (buf[l] == 'g')
+&& (buf[l+1] == 'r')
+&& (buf[l+2] == 'a')
+&& (buf[l+3] == 'y')
+&& (buf[l+4] == ' ')
+
+@ @<Handle a color push gray command@>=
+l = l + 5;
+while ( (l < len) && (buf[l] == ' ') ) incr(l); /* Remove spaces at end of buf */
+while ( (len > l) && (buf[len - 1] == ' ') ) decr(len);
+mpx->color_stack[mpx->color_stack_depth]=xmalloc((size_t)(len-l+9),1);
+strcpy(mpx->color_stack[mpx->color_stack_depth],"white*");
+k = 6;
+@<Copy |buf[l]| to |color_stack[color_stack_depth][k]| in tuple form@>
+
+@ @<|buf[l]| contains a cmyk command@>=
+(l + 5 < len)
+&& (buf[l] == 'c')
+&& (buf[l+1] == 'm')
+&& (buf[l+2] == 'y')
+&& (buf[l+3] == 'k')
+&& (buf[l+4] == ' ')
+
+@ @<Handle a color push cmyk command@>=
+l = l + 5;
+while ( (l < len) && (buf[l] == ' ') ) incr(l);
+/* Remove spaces at end of buf */
+while ( (len > l) && (buf[len - 1] == ' ') ) decr(len);
+mpx->color_stack[mpx->color_stack_depth]=xmalloc((size_t)(len-l+7),1);
+strcpy(mpx->color_stack[mpx->color_stack_depth],"cmyk");
+k = 4;
+@<Copy |buf[l]| to |color_stack[color_stack_depth][k]| in tuple form@>
+
+@ @<Copy |buf[l]| to |color_stack[color_stack_depth][k]| in tuple form@>=
+mpx->color_stack[mpx->color_stack_depth][k] = '(';
+incr(k);
+while ( l < len ) {
+ if ( buf[l] == ' ' ) {
+ mpx->color_stack[mpx->color_stack_depth][k] = ',';
+ while ( (l < len) && (buf[l] == ' ') ) incr(l);
+ incr(k);
+ } else {
+ mpx->color_stack[mpx->color_stack_depth][k] = (char)buf[l];
+ incr(l);
+ incr(k);
+ }
+}
+mpx->color_stack[mpx->color_stack_depth][k] = ')';
+mpx->color_stack[mpx->color_stack_depth][k+1] = 0;
+
+@ Binary-search the |named_colors| array, then push the found color onto
+the stack.
+
+@<Handle a named color push command@>=
+for (k = l;k<=len - 1;k++) {
+ buf[k - l] = xchr(buf[k]);
+}
+buf[len - l] = 0;
+len = len - l;
+l = 1; r = mpx->num_named_colors;
+found = false;
+while ( (l <= r) && ! found ) {
+ m = (l + r) / 2; k = strcmp((char *)(buf), mpx->named_colors[m].name);
+ if ( k == 0 ) {
+ mpx->color_stack[mpx->color_stack_depth]=xstrdup(mpx->named_colors[m].value);
+ found = true;
+ } else if ( k < 0 ) {
+ r = m - 1;
+ } else {
+ l = m + 1;
+ }
+}
+if (! found ) {
+ color_warn_two("non-hardcoded color \"%s\" in \"color push\" command", buf);
+ mpx->color_stack[mpx->color_stack_depth]=xstrdup((char *)(buf));
+}
+
+@ Last but not least, this code snippet prints a \.{withcolor} specifier
+for the top of the color stack, if the stack is nonempty.
+
+@<Print a \.{withcolor} specifier if appropriate@>=
+if ( mpx->color_stack_depth > 0 ) {
+ fprintf(mpx->mpxfile," withcolor %s\n",mpx->color_stack[mpx->color_stack_depth]);
+}
+
+
+@* \[4] Dmp.
+
+This program reads device-independent troff output files,
+and converts them into a symbolic form understood by MetaPost. Some
+of the code was borrowed from DVItoMP. It understands all the D? graphics
+functions that dpost does but it ignores `x X' device control functions
+such as `x X SetColor:...', `x X BeginPath:', and `x X DrawPath:...'.
+
+The output file is a sequence of MetaPost picture expressions, one for every
+page in the input file. It makes no difference where the input file comes
+from, but it is intended to process the result of running eqn and troff on
+the output of MPtoTR. Such a file contains one page for every btex...etex
+block in the original input. This program then creates a corresponding
+sequence of MetaPost picture expressions for use as an auxiliary input file.
+Since MetaPost expects such files to have the extension .mpx, the output
+is sometimes called an `mpx' file.
+
+@d SHIFTS 100 /* maximum number of characters with special shifts */
+@d MAXCHARS 256 /* character codes fall in the range 0..MAXCHARS-1 */
+
+@d is_specchar(c) (!mpx->gflag && (c)<=2) /* does charcode c identify a special char? */
+@d LWscale 0.03 /* line width for graphics as a fraction of pointsize */
+@d YCORR 12.0 /* V coordinate of reference point in (big) points */
+
+@<Globals@>=
+int next_specfnt[(max_fnums+1)]; /* used to link special fonts together */
+int shiftchar[SHIFTS]; /* charcode of character to shift, else -1 */
+float shifth[SHIFTS];
+float shiftv[SHIFTS]; /* shift vals/fontsize (y is upward) */
+int shiftptr; /* number of entries in shift tables */
+int shiftbase[(max_fnums+1)]; /* initial index into shifth,shiftv,shiftchar */
+int specfnt; /* int. num. of first special font (or FCOUNT) */
+int *specf_tail ; /* tail of specfnt list |(*specf_tail==FCOUNT)| */
+float cursize; /* current type size in (big) points */
+unsigned int curfont; /* internal number for current font */
+float Xslant; /* degrees additional slant for all fonts */
+float Xheight; /* yscale fonts to this height if nonzero */
+float sizescale; /* groff font size scaling factor */
+int gflag; /* non-zero if using groff fonts */
+float unit; /* (big) points per troff unit (0 when unset) */
+
+@ @<Set initial...@>=
+mpx->shiftptr = 0;
+mpx->specfnt = (max_fnums+1);
+mpx->specf_tail = &(mpx->specfnt);
+mpx->unit = 0.0;
+mpx->lnno = 0; /* this is a reset */
+mpx->gflag = 0;
+mpx->h = 0; mpx->v = 0;
+
+@ @(mpxout.h@>=
+typedef char *(*mpx_file_finder)(MPX, const char *, const char *, int);
+enum mpx_filetype {
+ mpx_tfm_format, /* |kpse_tfm_format| */
+ mpx_vf_format, /* |kpse_vf_format| */
+ mpx_trfontmap_format, /* |kpse_mpsupport_format| */
+ mpx_trcharadj_format, /* |kpse_mpsupport_format| */
+ mpx_desc_format, /* |kpse_troff_font_format| */
+ mpx_fontdesc_format, /* |kpse_troff_font_format| */
+ mpx_specchar_format /* |kpse_mpsupport_format| */
+};
+
+@ @<Globals@>=
+mpx_file_finder find_file;
+
+@ @<Declarations@>=
+static char *mpx_find_file (MPX mpx, const char *nam, const char *mode, int ftype);
+
+@ @c
+static char *mpx_find_file (MPX mpx, const char *nam, const char *mode, int ftype) {
+ (void) mpx;
+ if (mode[0] != 'r' || (! access (nam,R_OK)) || ftype) {
+ return strdup(nam);
+ }
+ return NULL;
+}
+
+@ @<Set initial...@>=
+mpx->find_file = mpx_find_file;
+
+@ @<Declarations@>=
+static FILE *mpx_fsearch(MPX mpx, char *nam, int format);
+
+@ @c
+static FILE *mpx_fsearch(MPX mpx, char *nam, int format) {
+ FILE *f = NULL;
+ char *fname = (mpx->find_file)(mpx, nam, "r", format);
+ if (fname) {
+ f = fopen(fname, "rb");
+ mpx_report(mpx,"%p = fopen(%s,\"rb\")",f, fname);
+ }
+ return f;
+}
+
+@ Hash tables (or rather: AVL lists)
+
+@ @<Types...@>=
+typedef struct {
+ char *name;
+ int num;
+} avl_entry;
+
+@ @c
+static int mpx_comp_name (void *p, const void *pa, const void *pb) {
+ (void)p;
+ return strcmp (((const avl_entry *) pa)->name,
+ ((const avl_entry *) pb)->name);
+}
+static void *destroy_avl_entry (void *pa) {
+ avl_entry *p;
+ p = (avl_entry *) pa;
+ free (p->name);
+ free (p);
+ return NULL;
+}
+static void *copy_avl_entry (const void *pa) { /* never used */
+ avl_entry *p, *q;
+ p = (avl_entry *) pa;
+ q = malloc(sizeof(avl_entry));
+ if (q!=NULL) {
+ q->name = strdup(p->name);
+ q->num = p->num;
+ }
+ return (void *)q;
+}
+
+
+@ @c
+static avl_tree mpx_avl_create (MPX mpx) {
+ avl_tree t;
+ t = avl_create(mpx_comp_name,
+ copy_avl_entry,
+ destroy_avl_entry,
+ malloc, free, NULL);
+ if (t==NULL)
+ mpx_abort(mpx, "Memory allocation failure");
+ return t;
+}
+
+@ The only two operations on AVL lists are finding already existing
+items, or interning new items. Finding is handled by explicit |avl_find|
+calls where needed, but it is wise to have a wrapper around |avl_probe|
+to check for memory errors.
+
+@c
+static avl_entry * mpx_avl_probe(MPX mpx, avl_tree tab, avl_entry *p) {
+ avl_entry *r = (avl_entry *)avl_probe(tab,p);
+ if (r==NULL)
+ mpx_abort(mpx,"Memory allocation failure");
+ return r;
+
+}
+
+
+@ Scanning Numbers
+
+The standard functions atoi(), atof(), and sscanf() provide ways of reading
+numbers from strings but they give no indication of how much of the string
+is consumed. These homemade versions don't parse scientific notation.
+
+@<Globals@>=
+char *arg_tail; /* char after the number just gotten; NULL on failure */
+
+@ @c
+static int mpx_get_int(MPX mpx, char *s) {
+ register int i, d, neg;
+ if (s == NULL)
+ goto BAD;
+ for (neg = 0;; s++) {
+ if (*s == '-')
+ neg = !neg;
+ else if (*s != ' ' && *s != '\t')
+ break;
+ }
+ if (i = *s - '0', 0 > i || i > 9)
+ goto BAD;
+ while (d = *++s - '0', 0 <= d && d <= 9)
+ i = 10 * i + d;
+ mpx->arg_tail = s;
+ return neg ? -i : i;
+ BAD:
+ mpx->arg_tail = NULL;
+ return 0;
+}
+
+@ GROFF font description files use octal character codes
+|groff_font(5)|: The code can be any web_integer. If it starts with
+a 0 it will be interpreted as octal; if it starts with 0x
+or 0X it will be intepreted as hexadecimal.
+
+@c
+static int mpx_get_int_map(MPX mpx, char *s) {
+ register int i;
+ if (s == NULL)
+ goto BAD;
+ i = strtol(s, &(mpx->arg_tail), 0);
+ if (s == mpx->arg_tail)
+ goto BAD;
+ return i;
+BAD:
+ mpx->arg_tail = NULL;
+ return 0;
+}
+
+@ Troff output files contain few if any non-web_integers, but this program is
+prepared to read floats whenever they seem reasonable; i.e., when the
+number is not being used for character positioning. (For non-PostScript
+applications h and v are usually in pixels and should be web_integers.)
+
+@c
+static float mpx_get_float(MPX mpx, char *s) {
+ register int d, neg, digits;
+ register float x, y;
+ digits = 0;
+ neg = 0; x=0.0;
+ if (s != NULL) {
+ for (neg = 0;; s++) {
+ if (*s == '-')
+ neg = !neg;
+ else if (*s != ' ' && *s != '\t')
+ break;
+ }
+ x = 0.0;
+ while (d = *s - '0', 0 <= d && d <= 9) {
+ x = 10.0 * x + d;
+ digits++;
+ s++;
+ }
+ if (*s == '.') {
+ y = 1.0;
+ while (d = *++s - '0', 0 <= d && d <= 9) {
+ y /= 10.0;
+ x += y * d;
+ digits++;
+ }
+ }
+ }
+ if (digits == 0) {
+ mpx->arg_tail = NULL;
+ return 0.0;
+ }
+ mpx->arg_tail = s;
+ return neg ? -x : x;
+}
+
+@ GROFF font description files have metrics field
+of comma-separated web_integers. Traditional troff
+have a float in this position. The value is not
+used anyway - thus just skip the value,
+ eat all non-space chars.
+
+@c
+static float mpx_get_float_map(MPX mpx, char *s) {
+ if (s != NULL) {
+ while (isspace(*s))
+ s++;
+ while (!isspace(*s) && *s)
+ s++;
+ }
+ mpx->arg_tail = s;
+ return 0;
+}
+
+
+@ Reading Initialization Files
+
+Read the database file, reserve internal font numbers and set
+the |font_name| entries. Each line in the database file contains
+|<troff-name>\t,PostScript-name>\t<TeX-name>|
+or just
+|<troff-name>\t,PostScript-name>|
+if the \TeX\ name matches the PostScript name. (|\t| means one or more tabs.)
+
+@<Globals@>=
+avl_tree trfonts;
+
+@ @c
+static void mpx_read_fmap(MPX mpx, char *dbase) {
+ FILE *fin;
+ avl_entry *tmp;
+ char *nam; /* a font name being read */
+ char *buf;
+ mpx->nfonts = 0;
+ fin = mpx_fsearch(mpx,dbase, mpx_trfontmap_format);
+ if (fin==NULL)
+ mpx_abort(mpx,"Cannot find %s", dbase);
+
+ mpx->trfonts = mpx_avl_create (mpx);
+ while ((buf = mpx_getline(mpx,fin)) != NULL) {
+ if (mpx->nfonts == (max_fnums+1))
+ mpx_abort(mpx,"Need to increase max_fnums");
+ nam = buf;
+ while (*buf && *buf != '\t')
+ buf++;
+ tmp = xmalloc(sizeof(avl_entry),1);
+ tmp->name = nam;
+ tmp->num = (int)mpx->nfonts++;
+ (void)mpx_avl_probe (mpx,mpx->trfonts, tmp) ;
+ if (*buf) {
+ *buf = 0; buf++;
+ do buf++; while (*buf == '\t');
+ while (*buf && *buf != '\t'); buf++; /* skip over psname */
+ do buf++; while (*buf == '\t');
+ if (*buf)
+ nam = buf;
+ while (*buf); buf++;
+ }
+ mpx->font_name[tmp->num] = xstrdup(nam);
+ mpx->font_num[tmp->num] = -1; /* indicate font is not mounted */
+ mpx->nfonts++;
+ }
+ mpx_fclose(mpx,fin);
+}
+
+
+@ Some characters need their coordinates shifted in order to agree with
+troff's view of the world. Logically, this information belongs in the
+font description files but it actually resides in a PostScript prolog
+that the troff output processor dpost reads. Since that file is in
+PostScript and subject to change, we read the same information from
+a small auxiliary file that gives shift amounts relative to the font
+size with y upward.
+
+GROFF NOTE:
+The PostScript prologue in GNU groff's font directory does not
+contain any character shift information, so the following function
+becomes redundant. Simply keeping an empty "trchars.adj" file
+around will do fine without requiring any changes to this program.
+
+@c
+static void mpx_read_char_adj(MPX mpx, char *adjfile) {
+ FILE *fin;
+ char buf[200];
+ avl_entry tmp, *p;
+ unsigned int i;
+
+ fin = mpx_fsearch(mpx,adjfile, mpx_trcharadj_format);
+ if (fin==NULL)
+ mpx_abort(mpx,"Cannot find %s", adjfile);
+
+ for (i = 0; i < mpx->nfonts; i++)
+ mpx->shiftbase[i] = 0;
+ while (fgets(buf, 200, fin) != NULL) {
+ if (mpx->shiftptr == SHIFTS - 1)
+ mpx_abort(mpx,"Need to increase SHIFTS");
+ if (buf[0] != ' ' && buf[0] != '\t') {
+ for (i = 0; buf[i] != '\0'; i++)
+ if (buf[i] == '\n')
+ buf[i] = '\0';
+ mpx->shiftchar[mpx->shiftptr++] = -1;
+ tmp.name = buf;
+ p = (avl_entry *)avl_find (&tmp, mpx->trfonts);
+ if (p==NULL)
+ mpx_abort(mpx,"%s refers to unknown font %s", adjfile, buf);
+ mpx->shiftbase[p->num] = mpx->shiftptr;
+
+ } else {
+ mpx->shiftchar[mpx->shiftptr] = mpx_get_int(mpx,buf);
+ mpx->shifth[mpx->shiftptr] = mpx_get_float(mpx,mpx->arg_tail);
+ mpx->shiftv[mpx->shiftptr] = -mpx_get_float(mpx,mpx->arg_tail);
+ if (mpx->arg_tail == NULL)
+ mpx_abort(mpx,"Bad shift entry : \"%s\"", buf);
+ mpx->shiftptr++;
+ }
+ }
+ mpx->shiftchar[mpx->shiftptr++] = -1;
+ mpx_fclose(mpx,fin);
+}
+
+@ Read the DESC file of the troff device to gather information
+ about sizescale and whether running under groff.
+
+Ignore all commands not specially handled. This relieves
+of collecting commands without arguments here and also
+makes the program more robust in case of future DESC
+extensions.
+
+@c
+static void mpx_read_desc(MPX mpx) {
+ const char *const k1[] = {
+ "res", "hor", "vert", "unitwidth", "paperwidth",
+ "paperlength", "biggestfont", "spare2", "encoding",
+ NULL
+ };
+ const char *const g1[] = {
+ "family", "paperheight", "postpro", "prepro",
+ "print", "image_generator", "broken",
+ NULL
+ };
+ char cmd[200];
+ FILE *fp;
+ int i, n;
+
+ fp = mpx_fsearch(mpx,"DESC", mpx_desc_format);
+ if (fp==NULL)
+ mpx_abort(mpx,"Cannot find DESC");
+ while (fscanf(fp, "%199s", cmd) != EOF) {
+ if (*cmd == '#') {
+ while ((i = getc(fp)) != EOF && i != '\n');
+ continue;
+ }
+ if (strcmp(cmd, "fonts") == 0) {
+ if (fscanf(fp, "%d", &n) != 1)
+ return;
+ for (i = 0; i < n; i++)
+ if (fscanf(fp, "%*s") == EOF)
+ return;
+ } else if (strcmp(cmd, "sizes") == 0) {
+ while (fscanf(fp, "%d", &n) == 1 && n != 0);
+ } else if (strcmp(cmd, "styles") == 0 ||
+ strcmp(cmd, "papersize") == 0) {
+ mpx->gflag++;
+ while ((i = getc(fp)) != EOF && i != '\n');
+ } else if (strcmp(cmd, "sizescale") == 0) {
+ if (fscanf(fp, "%d", &n) == 1)
+ mpx->sizescale = (float)n;
+ mpx->gflag++;
+ } else if (strcmp(cmd, "charset") == 0) {
+ return;
+ } else {
+ for (i = 0; k1[i]; i++)
+ if (strcmp(cmd, k1[i]) == 0) {
+ if (fscanf(fp, "%*s") == EOF)
+ return;
+ break;
+ }
+ if (k1[i] == 0)
+ for (i = 0; g1[i]; i++)
+ if (strcmp(cmd, g1[i]) == 0) {
+ if (fscanf(fp, "%*s") == EOF)
+ return;
+ mpx->gflag = 1;
+ break;
+ }
+ }
+ }
+}
+
+
+@ Given one line from the character description file for the font with
+internal number f, save the appropriate data in the charcodes[f] table.
+A return value of zero indicates a syntax error.
+
+GROFF:
+GNU groff uses an extended font description file format documented
+in |groff_font(5)|. In order to allow parsing of groff's font files,
+this function needs to be rewritten as follows:
+
+\item{1.}The `metrics' field parsed by |mpx_get_float(lin);| may include
+ a comma-separated list of up to six decimal web_integers rather
+ than just a single floating-point number.
+
+\item{2.}The `charcode' field parsed by |lastcode = mpx_get_int(arg_tail);|
+ may be given either in decimal, octal, or hexadecimal format.
+
+@ @<Globals@>=
+avl_tree charcodes[(max_fnums+1)]; /* hash tables for translating char names */
+
+@ @c
+static int mpx_scan_desc_line(MPX mpx, int f, char *lin) {
+ static int lastcode;
+ avl_entry *tmp;
+ char *s, *t;
+ t = lin;
+ while (*lin != ' ' && *lin != '\t' && *lin != '\0')
+ lin++;
+ s = xmalloc((size_t)(lin-t+1),1);
+ strncpy(s,t,(size_t)(lin-t));
+ while (*lin == ' ' || *lin == '\t')
+ lin++;
+ if (*lin == '"') {
+ if (lastcode < MAXCHARS) {
+ tmp = xmalloc(sizeof(avl_entry),1);
+ tmp->name = s ;
+ tmp->num = lastcode;
+ (void)mpx_avl_probe (mpx, mpx->charcodes[f],tmp);
+ }
+ } else {
+ (void) mpx_get_float_map(mpx,lin);
+ (void) mpx_get_int(mpx,mpx->arg_tail);
+ lastcode = mpx_get_int_map(mpx,mpx->arg_tail);
+ if (mpx->arg_tail == NULL)
+ return 0;
+ if (lastcode < MAXCHARS) {
+ tmp = xmalloc(sizeof(avl_entry),1);
+ tmp->name = s ;
+ tmp->num = lastcode;
+ (void)mpx_avl_probe (mpx, mpx->charcodes[f],tmp);
+ }
+ }
+ return 1;
+}
+
+@ Read the font description file for the font with the given troff name
+and update the data structures. The result is the internal font number.
+
+@c
+static int mpx_read_fontdesc(MPX mpx, char *nam) { /* troff name */
+ char buf[200];
+ avl_entry tmp, *p;
+ FILE *fin; /* input file */
+ int f; /* internal font number */
+
+ if (mpx->unit == 0.0)
+ mpx_abort(mpx, "Resolution is not set soon enough");
+ tmp.name = nam;
+ p = (avl_entry *)avl_find (&tmp,mpx->trfonts);
+ if (p == NULL)
+ mpx_abort(mpx, "Font was not in map file");
+ f = p->num;
+ fin = mpx_fsearch(mpx, nam, mpx_fontdesc_format);
+ if (fin==NULL)
+ mpx_abort(mpx,"Cannot find %s", nam);
+ for (;;) {
+ if (fgets(buf, 200, fin) == NULL)
+ mpx_abort(mpx, "Description file for %s ends unexpectedly", nam);
+ if (strncmp(buf, "special", 7) == 0) {
+ *(mpx->specf_tail) = f;
+ mpx->next_specfnt[f] = (max_fnums+1);
+ mpx->specf_tail = &(mpx->next_specfnt[f]);
+ } else if (strncmp(buf, "charset", 7) == 0)
+ break;
+ }
+ mpx->charcodes[f] = mpx_avl_create (mpx);
+ while (fgets(buf, 200, fin) != NULL)
+ if (mpx_scan_desc_line(mpx, f, buf) == 0)
+ mpx_abort(mpx, "%s has a bad line in its description file: %s", nam, buf);
+ mpx_fclose(mpx,fin);
+ return f;
+}
+
+@ Page and Character Output
+
+@<Globals@>=
+boolean graphics_used; /* nonzero if any graphics seen on this page */
+float dmp_str_h1;
+float dmp_str_v; /* corrected start pos for current out string */
+float dmp_str_h2; /* where the current output string ends */
+float str_size; /* point size for this text string */
+
+
+@ Print any transformations required by the current Xslant and Xheight settings.
+
+@<Declarations@>=
+static void mpx_slant_and_ht(MPX mpx);
+
+@ @c
+static void mpx_slant_and_ht(MPX mpx) {
+ int i = 0;
+ if (mpx->Xslant != 0.0) {
+ fprintf(mpx->mpxfile, " slanted%.5f", mpx->Xslant);
+ i++;
+ }
+ if (mpx->Xheight != mpx->cursize && mpx->Xheight != 0.0 && mpx->cursize != 0.0) {
+ fprintf(mpx->mpxfile, " yscaled%.4f", mpx->Xheight / mpx->cursize);
+ i++;
+ }
+ if (i > 0)
+ fprintf(mpx->mpxfile, "\n ");
+}
+
+
+@ Output character number c in the font with internal number f.
+
+@c
+static void mpx_set_num_char(MPX mpx, int f, int c) {
+ float hh, vv; /* corrected versions of h, v */
+ int i;
+
+ hh = (float)mpx->h;
+ vv = (float)mpx->v;
+ for (i = mpx->shiftbase[f]; mpx->shiftchar[i] >= 0; i++)
+ if (mpx->shiftchar[i] == c) {
+ hh += (mpx->cursize / mpx->unit) * mpx->shifth[i];
+ vv += (mpx->cursize / mpx->unit) * mpx->shiftv[i];
+ break;
+ }
+ if (hh - mpx->dmp_str_h2 >= 1.0 || mpx->dmp_str_h2 - hh >= 1.0 ||
+ vv - mpx->dmp_str_v >= 1.0 || mpx->dmp_str_v - vv >= 1.0 ||
+ f != mpx->str_f || mpx->cursize != mpx->str_size) {
+ if (mpx->str_f >= 0)
+ mpx_finish_last_char(mpx);
+ else if (!mpx->fonts_used)
+ mpx_prepare_font_use(mpx); /* first font usage on this page */
+ if (!mpx->font_used[f])
+ mpx_first_use(mpx,f); /* first use of font f on this page */
+ fprintf(mpx->mpxfile, "_s((");
+ mpx->print_col = 3;
+ mpx->str_f = f;
+ mpx->dmp_str_v = vv;
+ mpx->dmp_str_h1 = hh;
+ mpx->str_size = mpx->cursize;
+ }
+ mpx_print_char(mpx, (unsigned char)c);
+ mpx->dmp_str_h2 = hh + char_width(f,c);
+}
+
+@ Output a string.
+
+@c
+static void mpx_set_string(MPX mpx, char *cname) {
+ float hh; /* corrected version of h, current horisontal position */
+
+ if (!*cname)
+ return;
+ hh = (float)mpx->h;
+ mpx_set_num_char(mpx,(int)mpx->curfont, *cname);
+ hh += char_width(mpx->curfont,(int)*cname);
+ while (*++cname) {
+ mpx_print_char(mpx,(unsigned char)*cname);
+ hh += char_width(mpx->curfont,(int)*cname);
+ }
+ mpx->h = (web_integer)floor(hh+0.5);
+ mpx_finish_last_char(mpx);
+}
+
+@ Special Characters
+
+Given the troff name of a special character, this routine finds its
+definition and copies it to the MPX file. It also finds the name of
+the vardef macro and returns that name. The name should be C.<something>.
+
+@
+TH: A bit of trickery is added here for case-insensitive
+file systems. This aliasing allows the CHARLIB directory
+to exist on DVDs, for example.
+It is a hack, I know. I've stuck to names on TeXLive.
+
+@d test_redo_search do {
+ if (deff==NULL)
+ deff = mpx_fsearch(mpx, cname, mpx_specchar_format);
+ } while (0)
+
+@c
+static char *mpx_copy_spec_char(MPX mpx, char *cname) {
+ FILE *deff;
+ int c;
+ char *s, *t;
+ char specintro[] = "vardef "; /* MetaPost name follows this */
+ unsigned k = 0; /* how much of specintro so far */
+ if (strcmp(cname, "ao") == 0) {
+ deff = mpx_fsearch(mpx, "ao.x", mpx_specchar_format);
+ test_redo_search;
+ } else if (strcmp(cname, "lh") == 0) {
+ deff = mpx_fsearch(mpx, "lh.x", mpx_specchar_format);
+ test_redo_search;
+ } else if (strcmp(cname, "~=") == 0) {
+ deff = mpx_fsearch(mpx, "twiddle", mpx_specchar_format);
+ test_redo_search;
+ } else {
+ deff = mpx_fsearch(mpx, cname, mpx_specchar_format);
+ }
+ if (deff==NULL)
+ mpx_abort(mpx, "No vardef in charlib/%s", cname);
+
+ while (k < (unsigned)strlen(specintro)) {
+ if ((c = getc(deff)) == EOF)
+ mpx_abort(mpx, "No vardef in charlib/%s", cname);
+ putc(c, mpx->mpxfile);
+ if (c == specintro[k])
+ k++;
+ else
+ k = 0;
+ }
+ s = xmalloc(mpx->bufsize,1);
+ t = s ;
+ while ((c = getc(deff)) != '(') {
+ if (c == EOF)
+ mpx_abort(mpx, "vardef in charlib/%s has no arguments", cname);
+ putc(c, mpx->mpxfile);
+ *t++ = c;
+ }
+ putc(c, mpx->mpxfile);
+ *t++ = '\0';
+ while ((c = getc(deff)) != EOF);
+ putc(c, mpx->mpxfile);
+ return s;
+}
+
+
+@ When given a character name instead of a number, we need to check if
+it is a special character and download the definition if necessary.
+If the character is not in the current font we have to search the special
+fonts.
+
+@<Globals@>=
+avl_tree spec_tab;
+
+@ The |spec_tab| avl table combines character names with macro names.
+
+@<Types...@>=
+typedef struct {
+ char *name;
+ char *mac;
+} spec_entry;
+
+@ @c
+static void mpx_set_char(MPX mpx, char *cname) {
+ int f, c;
+ avl_entry tmp, *p;
+ spec_entry *sp;
+
+ if (*cname == ' ' || *cname == '\t')
+ return;
+ f = (int)mpx->curfont;
+ tmp.name = cname;
+ p = avl_find(&tmp, mpx->charcodes[f]);
+ if (p==NULL) {
+ for (f = mpx->specfnt; f != (max_fnums+1); f = mpx->next_specfnt[f]) {
+ p = avl_find(&tmp, mpx->charcodes[f]);
+ if (p!=NULL)
+ goto OUT_LABEL;
+ }
+ mpx_abort(mpx, "There is no character %s", cname);
+ }
+OUT_LABEL:
+ c = p->num;
+ if (!is_specchar(c)) {
+ mpx_set_num_char(mpx, f, c);
+ } else {
+ if (mpx->str_f >= 0)
+ mpx_finish_last_char(mpx);
+ if (!mpx->fonts_used)
+ mpx_prepare_font_use(mpx);
+ if (!mpx->font_used[f])
+ mpx_first_use(mpx, f);
+ if (mpx->spec_tab)
+ mpx->spec_tab = mpx_avl_create (mpx);
+ sp = xmalloc(sizeof(spec_entry),1);
+ sp->name = cname;
+ sp->mac = NULL;
+ sp = (spec_entry *)avl_probe(mpx->spec_tab,sp);
+ if (sp==NULL)
+ mpx_abort(mpx,"Memory allocation failure");
+ if (sp->mac == NULL) {
+ sp->mac = mpx_copy_spec_char(mpx, cname); /* this won't be NULL */
+ }
+ fprintf(mpx->mpxfile, "_s(%s(n%d)", sp->mac, mpx->font_num[f]);
+ mpx_slant_and_ht(mpx);
+ fprintf(mpx->mpxfile, ",%.5f,%.4f,%.4f);\n",
+ (mpx->cursize/mpx->font_design_size[f])*1.00375,
+ (double)(mpx->h*mpx->unit), YCORR-mpx->v*mpx->unit);
+ }
+}
+
+@ Font Definitions
+
+Mount the font with troff name nam at external font number n and read any
+necessary font files.
+
+@c
+static void mpx_do_font_def(MPX mpx, int n, char *nam) {
+ int f;
+ unsigned k;
+ avl_entry tmp, *p;
+ tmp.name = nam;
+ p = (avl_entry *) avl_find (&tmp, mpx->trfonts);
+ if (p==NULL)
+ mpx_abort(mpx, "Font %s was not in map file", nam);
+ f = p->num;
+ if ( mpx->info_base[f]==max_widths ) {
+ mpx_read_fontdesc(mpx, nam);
+ mpx->cur_name = xstrdup(mpx->font_name[f]);
+ if (! mpx_open_tfm_file(mpx) )
+ font_abort("No TFM file found for ",f);
+@.no TFM file found@>
+ mpx_in_TFM(mpx, f);
+ }
+ for (k = 0; k < mpx->nfonts; k++)
+ if (mpx->font_num[k] == n)
+ mpx->font_num[k] = -1;
+ mpx->font_num[f] = n;
+ @<Do any other initialization required for the new font |f|@>;
+}
+
+
+
+@ Time on `makepath pencircle'
+
+Given the control points of a cubic Bernstein polynomial, evaluate it at t.
+
+@d Speed ((float) (PI/4.0))
+
+@c
+static float mpx_b_eval(const float *xx, float t) {
+ float zz[4];
+ register int i, j;
+ for (i = 0; i <= 3; i++)
+ zz[i] = xx[i];
+ for (i = 3; i > 0; i--)
+ for (j = 0; j < i; j++)
+ zz[j] += t * (zz[j + 1] - zz[j]);
+ return zz[0];
+}
+
+
+@ Find the direction angle at time t on the path `makepath pencircle'.
+The tables below give the Bezier control points for MetaPost's cubic
+approximation to the first octant of a unit circle.
+
+@c
+static const float xx[] = { 1.0, 1.0, 0.8946431597, 0.7071067812 };
+static const float yy[] = { 0.0, 0.2652164899, 0.5195704026, 0.7071067812 };
+
+@ @c
+static float mpx_circangle(float t) {
+ float ti;
+ ti = floor(t);
+ t -= ti;
+ return (float) atan(mpx_b_eval(yy, t) /
+ mpx_b_eval(xx, t)) + ti * Speed;
+}
+
+
+@ Find the spline parameter where `makepath pencircle' comes closest to
+ (cos(a)/2,sin(a)/2).
+
+@c
+static float mpx_circtime(float a) {
+ int i;
+ float t;
+ t = a / Speed;
+ for (i = 2; --i >= 0;)
+ t += (a - mpx_circangle(t)) / Speed;
+ return t;
+}
+
+
+
+@ Troff Graphics
+
+@<Globals@>=
+float gx;
+float gy; /* current point for graphics (init. (h,YCORR/mpx->unit-v) */
+
+@ @c
+static void mpx_prepare_graphics(MPX mpx) {
+
+ fprintf(mpx->mpxfile, "vardef _D(expr _d)expr _q =\n");
+ fprintf(mpx->mpxfile,
+ " addto _p doublepath _q withpen pencircle scaled _d; enddef;\n");
+ mpx->graphics_used = true;
+}
+
+
+@ This function prints the current position (gx,gy). Then if it can read dh dv
+from string s, it increments (gx,gy) and prints "--". By returning the rest
+of the string s or NULL if nothing could be read from s, it provides the
+argument for the next iteration.
+
+@c
+static char *mpx_do_line(MPX mpx, char *s) {
+ float dh, dv;
+
+ fprintf(mpx->mpxfile, "(%.3f,%.3f)", mpx->gx * mpx->unit, mpx->gy * mpx->unit);
+ dh = mpx_get_float(mpx, s);
+ dv = mpx_get_float(mpx, mpx->arg_tail);
+ if (mpx->arg_tail == NULL)
+ return NULL;
+ mpx->gx += dh;
+ mpx->gy -= dv;
+ fprintf(mpx->mpxfile, "--\n");
+ return mpx->arg_tail;
+}
+
+
+@ Function |spline_seg()| reads two pairs of (dh,dv) increments and prints the
+corresponding quadratic B-spline segment, leaving the ending point to be
+printed next time. The return value is the string with the first (dh,dv)
+pair lopped off. If only one pair of increments is found, we prepare to
+terminate the iteration by printing last time's ending point and returning
+NULL.
+
+@c
+static char * mpx_spline_seg(MPX mpx, char *s) {
+ float dh1, dv1, dh2, dv2;
+
+ dh1 = mpx_get_float(mpx, s);
+ dv1 = mpx_get_float(mpx, mpx->arg_tail);
+ if (mpx->arg_tail == NULL)
+ mpx_abort(mpx, "Missing spline increments");
+ s = mpx->arg_tail;
+ fprintf(mpx->mpxfile, "(%.3f,%.3f)", (mpx->gx + .5 * dh1) * mpx->unit,
+ (mpx->gy - .5 * dv1) * mpx->unit);
+ mpx->gx += dh1;
+ mpx->gy -= dv1;
+ dh2 = mpx_get_float(mpx, s);
+ dv2 = mpx_get_float(mpx, mpx->arg_tail);
+ if (mpx->arg_tail == NULL)
+ return NULL;
+ fprintf(mpx->mpxfile, "..\ncontrols (%.3f,%.3f) and (%.3f,%.3f)..\n",
+ (mpx->gx - dh1 / 6.0) * mpx->unit, (mpx->gy + dv1 / 6.0) * mpx->unit,
+ (mpx->gx + dh2 / 6.0) * mpx->unit, (mpx->gy - dv2 / 6.0) * mpx->unit);
+ return s;
+}
+
+
+@ Draw an ellipse with the given major and minor axes.
+
+@c
+static void mpx_do_ellipse(MPX mpx, float a, float b) {
+
+ fprintf(mpx->mpxfile, "makepath(pencircle xscaled %.3f\n yscaled %.3f",
+ a * mpx->unit, b * mpx->unit);
+ fprintf(mpx->mpxfile, " shifted (%.3f,%.3f));\n", (mpx->gx + .5 * a) * mpx->unit,
+ mpx->gy * mpx->unit);
+ mpx->gx += a;
+}
+
+
+@ Draw a counter-clockwise arc centered at (cx,cy) with initial and final radii
+ (ax,ay) and (bx,by) respectively.
+
+@c
+static
+void mpx_do_arc(MPX mpx, float cx, float cy, float ax, float ay, float bx, float by) {
+ float t1, t2;
+
+ t1 = mpx_circtime(atan2(ay, ax));
+ t2 = mpx_circtime(atan2(by, bx));
+ if (t2 < t1)
+ t2 += 8.0;
+ fprintf(mpx->mpxfile, "subpath (%.5f,%.5f) of\n", t1, t2);
+ fprintf(mpx->mpxfile,
+ " makepath(pencircle scaled %.3f shifted (%.3f,%.3f));\n",
+ 2.0 * sqrt(ax * ax + ay * ay) * mpx->unit, cx * mpx->unit, cy * mpx->unit);
+ mpx->gx = cx + bx;
+ mpx->gy = cy + by;
+}
+
+
+
+@ String s is everything following the initial `D' in a troff graphics command.
+
+@c
+static void mpx_do_graphic(MPX mpx, char *s) {
+ float h1, v1, h2, v2;
+
+ mpx_finish_last_char(mpx);
+ /* GROFF uses Fd to set fill color for solid drawing objects to the
+ default, so just ignore that.
+ */
+ if (s[0] == 'F' && s[1] == 'd')
+ return;
+ mpx->gx = (float) mpx->h;
+ mpx->gy = YCORR / mpx->unit - ((float) mpx->v);
+ if (!mpx->graphics_used)
+ mpx_prepare_graphics(mpx);
+ fprintf(mpx->mpxfile, "D(%.4f) ", LWscale * mpx->cursize);
+ switch (*s++) {
+ case 'c':
+ h1 = mpx_get_float(mpx,s);
+ if (mpx->arg_tail == NULL)
+ mpx_abort(mpx,"Bad argument in %s", s-2);
+ mpx_do_ellipse(mpx,h1, h1);
+ break;
+ case 'e':
+ h1 = mpx_get_float(mpx,s);
+ v1 = mpx_get_float(mpx,mpx->arg_tail);
+ if (mpx->arg_tail == NULL)
+ mpx_abort(mpx,"Bad argument in %s", s - 2);
+ mpx_do_ellipse(mpx,h1, v1);
+ break;
+ case 'A':
+ fprintf(mpx->mpxfile, "reverse ");
+ /* fall through */
+ case 'a':
+ h1 = mpx_get_float(mpx,s);
+ v1 = mpx_get_float(mpx,mpx->arg_tail);
+ h2 = mpx_get_float(mpx,mpx->arg_tail);
+ v2 = mpx_get_float(mpx,mpx->arg_tail);
+ if (mpx->arg_tail == NULL)
+ mpx_abort(mpx,"Bad argument in %s", s - 2);
+ mpx_do_arc(mpx,mpx->gx + h1, mpx->gy - v1, -h1, v1, h2, -v2);
+ break;
+ case 'l':
+ case 'p':
+ while (s != NULL)
+ s = mpx_do_line(mpx,s);
+ fprintf(mpx->mpxfile, ";\n");
+ break;
+ case 'q':
+ do
+ s = mpx_spline_seg(mpx,s);
+ while (s != NULL);
+ fprintf(mpx->mpxfile, ";\n");
+ break;
+ case '~':
+ fprintf(mpx->mpxfile, "(%.3f,%.3f)--", mpx->gx * mpx->unit, mpx->gy * mpx->unit);
+ do
+ s = mpx_spline_seg(mpx,s);
+ while (s != NULL);
+ fprintf(mpx->mpxfile, "--(%.3f,%.3f);\n", mpx->gx * mpx->unit, mpx->gy * mpx->unit);
+ break;
+ default:
+ mpx_abort(mpx,"Unknown drawing function %s", s - 2);
+ }
+ mpx->h = (int) floor(mpx->gx + .5);
+ mpx->v = (int) floor(YCORR / mpx->unit + .5 - mpx->gy);
+}
+
+
+
+@ Interpreting Troff Output
+
+@c
+static void mpx_change_font(MPX mpx, int f) {
+ for (mpx->curfont = 0; mpx->curfont < mpx->nfonts; mpx->curfont++)
+ if (mpx->font_num[mpx->curfont] == f)
+ return;
+ mpx_abort(mpx,"Bad font setting");
+}
+
+
+@ String s0 is everything following the initial `x' in a troff device control
+ command. A zero result indicates a stop command.
+
+@c
+static int mpx_do_x_cmd(MPX mpx, char *s0)
+{
+ float x;
+ int n;
+ char *s;
+
+ s = s0;
+ while (*s == ' ' || *s == '\t')
+ s++;
+ switch (*s++) {
+ case 'r':
+ if (mpx->unit != 0.0)
+ mpx_abort(mpx,"Attempt to reset resolution");
+ while (*s != ' ' && *s != '\t')
+ s++;
+ mpx->unit = mpx_get_float(mpx,s);
+ if (mpx->unit <= 0.0)
+ mpx_abort(mpx,"Bad resolution: x %s", s0);
+ mpx->unit = 72.0 / mpx->unit;
+ break;
+ case 'f':
+ while (*s != ' ' && *s != '\t')
+ s++;
+ n = mpx_get_int(mpx,s);
+ if (mpx->arg_tail == NULL)
+ mpx_abort(mpx,"Bad font def: x %s", s0);
+ s = mpx->arg_tail;
+ while (*s == ' ' || *s == '\t')
+ s++;
+ mpx_do_font_def(mpx,n, s);
+ break;
+ case 's':
+ return 0;
+ case 'H':
+ while (*s != ' ' && *s != '\t')
+ s++;
+ mpx->Xheight = mpx_get_float(mpx,s);
+ /* GROFF troff output is scaled |groff_out(5)|:
+ The argument to the s command is in scaled
+ points (units of points/n, where n is the argument
+ to the sizescale command in the DESC file.) The
+ argument to the x Height command is also in scaled points.
+ sizescale for groff devps is 1000
+ */
+ if (mpx->sizescale != 0.0) {
+ if (mpx->unit != 0.0)
+ mpx->Xheight *= mpx->unit; /* ??? */
+ else
+ mpx->Xheight /= mpx->sizescale;
+ }
+ if (mpx->Xheight == mpx->cursize)
+ mpx->Xheight = 0.0;
+ break;
+ case 'S':
+ while (*s != ' ' && *s != '\t')
+ s++;
+ mpx->Xslant = mpx_get_float(mpx,s) * (PI / 180.0);
+ x = cos(mpx->Xslant);
+ if (-1e-4 < x && x < 1e-4)
+ mpx_abort(mpx,"Excessive slant");
+ mpx->Xslant = sin(mpx->Xslant) / x;
+ break;
+ default:
+ /* do nothing */ ;
+ }
+ return 1;
+}
+
+
+@ This routine reads commands from the troff output file up to and including
+the next `p' or `x s' command. It also calls |set_num_char()| and |set_char()|
+to generate output when appropriate. A zero result indicates that there
+are no more pages to do.
+
+GROFF:
+GNU groff uses an extended device-independent output file format
+documented in |groff_out(5)|. In order to allow parsing of groff's
+output files, this function either needs to be extended to support
+the new command codes, or else the use of the "t" and "u" commands
+must be disabled by removing the line "tcommand" from the DESC file
+in the \$(prefix)/lib/groff/devps directory.
+
+@c
+static int mpx_do_page (MPX mpx, FILE *trf) {
+ char *buf;
+ char a, *c, *cc;
+
+ mpx->h = mpx->v = 0;
+ while ((buf = mpx_getline(mpx, trf)) != NULL) {
+ mpx->lnno++;
+ c = buf;
+ while (*c != '\0') {
+ switch (*c) {
+ case ' ':
+ case '\t':
+ case 'w':
+ c++;
+ break;
+ case 's':
+ mpx->cursize = mpx_get_float(mpx,c + 1);
+ /* GROFF troff output is scaled
+ |groff_out(5)|: The argument to the s command is in scaled
+ points (units of points/n, where n is the argument
+ to the sizescale command in the DESC file.) The
+ argument to the x Height command is also in scaled
+ points.
+ sizescale for groff devps is 1000
+ */
+ if (mpx->sizescale != 0.0) {
+ if (mpx->unit != 0.0)
+ mpx->cursize *= mpx->unit; /* ??? */
+ else
+ mpx->cursize /= mpx->sizescale;
+ }
+ goto iarg;
+ case 'f':
+ mpx_change_font(mpx, mpx_get_int(mpx,c + 1));
+ goto iarg;
+ case 'c':
+ if (c[1] == '\0')
+ mpx_abort(mpx, "Bad c command in troff output");
+ cc = c + 2;
+ goto set;
+ case 'C':
+ cc = c;
+ do
+ cc++;
+ while (*cc != ' ' && *cc != '\t' && *cc != '\0');
+ goto set;
+ case 'N':
+ mpx_set_num_char(mpx, (int)mpx->curfont, mpx_get_int(mpx,c + 1));
+ goto iarg;
+ case 'H':
+ mpx->h = mpx_get_int(mpx, c + 1);
+ goto iarg;
+ case 'V':
+ mpx->v = mpx_get_int(mpx, c + 1);
+ goto iarg;
+ case 'h':
+ mpx->h += mpx_get_int(mpx, c + 1);
+ goto iarg;
+ case 'v':
+ mpx->v += mpx_get_int(mpx, c + 1);
+ goto iarg;
+ case '0':
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7':
+ case '8':
+ case '9':
+ if (c[1] < '0' || c[1] > '9' || c[2] == '\0')
+ mpx_abort(mpx, "Bad nnc command in troff output");
+ mpx->h += 10 * (c[0] - '0') + c[1] - '0';
+ c++;
+ cc = c + 2;
+ goto set;
+ case 'p':
+ return 1;
+ case 'n':
+ (void) mpx_get_int(mpx, c + 1);
+ (void) mpx_get_int(mpx, mpx->arg_tail);
+ goto iarg;
+ case 'D':
+ mpx_do_graphic(mpx, c + 1);
+ goto eoln;
+ case 'x':
+ if (!mpx_do_x_cmd(mpx, c + 1))
+ return 0;
+ goto eoln;
+ case '#':
+ goto eoln;
+ case 'F':
+ /* GROFF uses this command to report filename */
+ goto eoln;
+ case 'm':
+ /* GROFF uses this command to control color */
+ goto eoln;
+ case 'u':
+ /* GROFF uses this command to output a word with additional
+ white space between characters, not implemented
+ */
+ mpx_abort(mpx, "Bad command in troff output\n"
+ "change the DESC file for your GROFF PostScript device, remove tcommand");
+ case 't':
+ /* GROFF uses this command to output a word */
+ cc = c;
+ do
+ cc++;
+ while (*cc != ' ' && *cc != '\t' && *cc != '\0');
+ a = *cc;
+ *cc = '\0';
+ mpx_set_string(mpx, ++c);
+ c = cc;
+ *c = a;
+ continue;
+ default:
+ mpx_abort(mpx, "Bad command in troff output");
+ }
+ continue;
+ set:
+ a = *cc;
+ *cc = '\0';
+ mpx_set_char(mpx, ++c);
+ c = cc;
+ *c = a;
+ continue;
+ iarg:
+ c = mpx->arg_tail;
+ }
+ eoln: /* do nothing */ ;
+ }
+ return 0;
+}
+
+
+@ Main Dmp Program
+
+@d dbname "trfonts.map" /* file for table of troff \& TFM font names */
+@d adjname "trchars.adj" /* file for character shift amounts */
+
+@c
+static int mpx_dmp(MPX mpx, char *infile) {
+ int more;
+ FILE *trf = mpx_xfopen(mpx,infile, "r");
+ mpx_open_mpxfile(mpx);
+ if (mpx->banner != NULL)
+ fprintf (mpx->mpxfile,"%s\n",mpx->banner);
+ mpx_read_desc(mpx);
+ mpx_read_fmap(mpx,dbname);
+ if (!mpx->gflag)
+ mpx_read_char_adj(mpx,adjname);
+ if (mpx_do_page(mpx, trf)) {
+ do {
+ @<Do initialization required before starting a new page@>;
+ mpx_start_picture(mpx);
+ more = mpx_do_page(mpx,trf);
+ mpx_stop_picture(mpx);
+ fprintf(mpx->mpxfile, "mpxbreak\n");
+ } while (more);
+ }
+ mpx_fclose(mpx,trf);
+ mpx_fclose(mpx,mpx->mpxfile);
+ if ( mpx->history<=mpx_cksum_trouble )
+ return 0;
+ else
+ return mpx->history;
+}
+
+
+@* \[5] Makempx.
+
+
+Make an MPX file from the labels in a MetaPost source file,
+using mpto and either dvitomp (TeX) or dmp (troff).
+
+Started from a shell script initially based on John Hobby's original
+version, that was then translated to C by Akira Kakuto (Aug 1997,
+Aug 2001), and updated and largely rewritten by Taco Hoekwater (Nov 2006).
+
+
+Differences between the script and this C version:
+
+The script trapped HUP, INT, QUIT and TERM for cleaning up
+temporary files. This is a refinement, and not portable.
+
+The script put its own directory in front of the
+executable search PATH. This is not portable either, and
+it seems a safe bet that normal users do not have 'mpto',
+'dvitomp', or 'dmp' commands in their path.
+
+The command-line '-troff' now also accepts an optional argument.
+
+The troff infile for error diagnostics is renamed "mpxerr.i",
+not plain "mpxerr".
+
+The original script deleted mpx*.* in the cleanup process.
+
+That is a bit harder in C, because it requires reading the contents
+of the current directory. The current program assumes that
+opendir(), readdir() and closedir() are known everywhere where
+the function getcwd() exists (except on WIN32, where it uses
+|_findfirst| \& co).
+
+If this assumption is false, you can define |NO_GETCWD|, and makempx
+will revert to trying to delete only a few known extensions
+
+There is a -debug switch, preventing the removal of tmp files
+
+@d TMPNAME_EXT(a,b) { strcpy(a,tmpname); strcat(a,b); }
+
+@c
+
+#define TEXERR "mpxerr.tex"
+#define DVIERR "mpxerr.dvi"
+#define TROFF_INERR "mpxerr.i"
+#define TROFF_OUTERR "mpxerr.t"
+
+@ @c
+static void mpx_rename (MPX mpx, char *a, char *b) {
+ mpx_report(mpx,"renaming %s to %s",a,b);
+ rename(a,b);
+}
+
+@ @<Globals@>=
+char tex[15] ;
+int debug ;
+char *progname;
+
+@ Cleaning up
+@c
+static void mpx_default_erasetmp(MPX mpx) {
+ char *wrk;
+ char *p;
+ if (mpx->mode==mpx_tex_mode) {
+ wrk = xstrdup(mpx->tex);
+ p = strrchr(wrk, '.');
+ *p = '\0'; strcat(wrk, ".aux"); remove(wrk);
+ *p = '\0'; strcat(wrk, ".pdf"); remove(wrk);
+ *p = '\0'; strcat(wrk, ".toc"); remove(wrk);
+ *p = '\0'; strcat(wrk, ".idx"); remove(wrk);
+ *p = '\0'; strcat(wrk, ".ent"); remove(wrk);
+ *p = '\0'; strcat(wrk, ".out"); remove(wrk);
+ *p = '\0'; strcat(wrk, ".nav"); remove(wrk);
+ *p = '\0'; strcat(wrk, ".snm"); remove(wrk);
+ *p = '\0'; strcat(wrk, ".tui"); remove(wrk);
+ free(wrk);
+ }
+}
+
+@ @<Declarations@>=
+static void mpx_erasetmp(MPX mpx);
+
+@ @c
+static void mpx_cleandir(MPX mpx, char *cur_path) {
+ char *wrk, *p;
+#ifdef _WIN32
+ struct _finddata_t c_file;
+ long hFile;
+#else
+ struct dirent *entry;
+ DIR *d;
+#endif
+ wrk = xstrdup(mpx->tex);
+ p = strrchr(wrk, '.');
+ *p = '\0'; /* now wrk is identical to tmpname */
+
+#ifdef _WIN32
+ strcat(cur_path,"/*");
+ if ((hFile = _findfirst (cur_path, &c_file)) == -1L) {
+ mpx_default_erasetmp(mpx);
+ } else {
+ if (strstr(c_file.name,wrk)==c_file.name)
+ remove(c_file.name);
+ while (_findnext (hFile, &c_file) != -1L) {
+ if (strstr(c_file.name,wrk)==c_file.name)
+ remove(c_file.name);
+ }
+ _findclose (hFile); /* no more entries => close directory */
+ }
+#else
+ if ((d = opendir(cur_path)) == NULL) {
+ mpx_default_erasetmp(mpx);
+ } else {
+ while ((entry = readdir (d)) != NULL) {
+ if (strstr(entry->d_name,wrk)==entry->d_name)
+ remove(entry->d_name);
+ }
+ closedir(d);
+ }
+#endif
+ free(wrk);
+}
+
+
+@ It is important that |mpx_erasetmp| remains silent.
+If it find trouble, it should just ignore it.
+
+The string |cur_path| is a little bit larger than needed, because that
+allows the win32 code in |cleandir| to add the slash and asterisk for
+globbing without having to reallocate the variable first.
+
+@c
+#ifdef WIN32
+#define GETCWD _getcwd
+#else
+#define GETCWD getcwd
+#endif
+static void mpx_erasetmp(MPX mpx) {
+ char cur_path[1024];
+ if (mpx->debug)
+ return;
+ if (mpx->tex[0] != '\0') {
+ remove(mpx->tex);
+ if(GETCWD(cur_path,1020) == NULL) {
+ mpx_default_erasetmp(mpx); /* don't know where we are */
+ } else {
+ mpx_cleandir(mpx,cur_path);
+ }
+ }
+}
+
+
+@* Running the external typesetters.
+
+First, here is a helper for messaging.
+
+@c
+static char *mpx_print_command (MPX mpx, int cmdlength, char **cmdline) {
+ char *s, *t;
+ int i,l;
+ (void)mpx;
+ l = 0;
+ for (i = 0; i < cmdlength ; i++) {
+ l += strlen(cmdline[i])+1;
+ }
+ s = xmalloc((size_t)l,1); t=s;
+ for (i = 0; i < cmdlength ; i++) {
+ if (i>0) *t++ = ' ';
+ t = strcpy(t,cmdline[i]);
+ t += strlen(cmdline[i]);
+ }
+ return s;
+}
+
+@ This function unifies the external program calling across Posix-like and Win32
+systems.
+
+@c
+static int do_spawn (MPX mpx, char *cmd, char **options) {
+#ifndef WIN32
+ int retcode = -1;
+ pid_t child;
+ child = fork();
+ if (child < 0)
+ mpx_abort(mpx, "fork failed: %s", strerror(errno));
+ if (child == 0) {
+ if(execvp(cmd, options))
+ mpx_abort(mpx, "exec failed: %s", strerror(errno));
+ } else {
+ if (wait(&retcode)==child) {
+ retcode = (WIFEXITED(retcode) ? WEXITSTATUS(retcode) : -1);
+ } else {
+ mpx_abort(mpx, "wait failed: %s", strerror(errno));
+ }
+ }
+ return retcode;
+#else
+ (void)mpx;
+ return spawnvp(P_WAIT, cmd, (const char **)options);
+#endif
+}
+
+@ @c
+#ifdef WIN32
+#define nuldev "nul"
+#else
+#define nuldev "/dev/null"
+#endif
+static int mpx_run_command(MPX mpx, char *inname, char *outname, int count, char **cmdl) {
+ char *s;
+ int retcode;
+ int sav_o, sav_i; /* for I/O redirection */
+ FILE *fr, *fw; /* read and write streams for the command */
+
+ if (count < 1 || cmdl == NULL || cmdl[0] == NULL)
+ return -1; /* return non-zero by default, signalling an error */
+
+ s = mpx_print_command(mpx,count, cmdl);
+ mpx_report(mpx,"running command %s", s);
+ free(s);
+
+ fr = mpx_xfopen(mpx,(inname ? inname : nuldev), "r");
+ fw = mpx_xfopen(mpx,(outname ? outname : nuldev), "wb");
+ @<Save and redirect the standard I/O@>;
+ retcode = do_spawn(mpx,cmdl[0], cmdl);
+ @<Restore the standard I/O@>;
+ mpx_fclose(mpx,fr);
+ mpx_fclose(mpx,fw);
+ return retcode;
+}
+
+@ @ Running Troff is more likely than not a series of pipes that
+feed input to each other. Makempx does all of this itself by using
+temporary files inbetween. That means we have to juggle about with
+|stdin| and |stdout|.
+
+This is the only non-ansi C bit of makempx.
+@^system dependencies@>
+
+@<Save and redirect the standard I/O@>=
+#ifdef WIN32
+#define DUP _dup
+#define DUPP _dup2
+#else
+#define DUP dup
+#define DUPP dup2
+#endif
+sav_i = DUP(fileno(stdin));
+sav_o = DUP(fileno(stdout));
+DUPP(fileno(fr), fileno(stdin));
+DUPP(fileno(fw), fileno(stdout))
+
+@ @<Restore the standard I/O@>=
+DUPP(sav_i, fileno(stdin));
+close(sav_i);
+DUPP(sav_o, fileno(stdout));
+close(sav_o)
+
+@ The allocation of the array pointed to by |cmdline_addr| is of
+course much larger than is really needed, but it will still only be a
+few hunderd bytes at the most, and this ensures that the separate
+parts of the |maincmd| will all fit.
+
+@d split_command(a,b) mpx_do_split_command(mpx,a,&b,' ')
+@d split_pipes(a,b) mpx_do_split_command(mpx,a,&b,'|')
+
+@c
+static int
+mpx_do_split_command(MPX mpx, char *maincmd, char ***cmdline_addr, char target) {
+ char *piece;
+ char *cmd;
+ char **cmdline;
+ size_t i;
+ int ret = 0;
+ int in_string = 0;
+ if (strlen(maincmd) == 0)
+ return 0;
+ i = sizeof(char *)*(strlen(maincmd)+1);
+ cmdline = xmalloc(i,1);
+ memset(cmdline,0,i);
+ *cmdline_addr = cmdline;
+
+ i = 0;
+ while (maincmd[i] == ' ')
+ i++;
+ cmd = xstrdup(maincmd);
+ piece = cmd;
+ for (; i <= strlen(maincmd); i++) {
+ if (in_string == 1) {
+ if (cmd[i] == '"') {
+ in_string = 0;
+ }
+ } else if (in_string == 2) {
+ if (cmd[i] == '\'') {
+ in_string = 0;
+ }
+ } else {
+ if (cmd[i] == '"') {
+ in_string = 1;
+ } else if (cmd[i] == '\'') {
+ in_string = 2;
+ } else if (cmd[i] == target) {
+ cmd[i] = 0;
+ cmdline[ret++] = piece;
+ while (i < strlen(maincmd) && cmd[(i + 1)] == ' ')
+ i++;
+ piece = cmd + i + 1;
+ }
+ }
+ }
+ if (*piece) {
+ cmdline[ret++] = piece;
+ }
+ return ret;
+}
+
+@ @<Globals@>=
+char *maincmd; /* TeX command name */
+
+@ @c
+static void mpx_command_cleanup (MPX mpx, char **cmdline) {
+ (void)mpx;
+ xfree(cmdline[0]);
+ xfree(cmdline);
+}
+
+
+
+@ @c
+static void mpx_command_error (MPX mpx, int cmdlength, char **cmdline) {
+ char *s = mpx_print_command(mpx, cmdlength, cmdline);
+ mpx_command_cleanup(mpx, cmdline);
+ mpx_abort(mpx, "Command failed: %s; see mpxerr.log", s);
+}
+
+
+
+@ @(mpxout.h@>=
+typedef struct mpx_options {
+ int mode;
+ char *cmd;
+ char *mptexpre;
+ char *mpname;
+ char *mpxname;
+ char *banner;
+ int debug;
+ mpx_file_finder find_file;
+} mpx_options;
+int mpx_makempx (mpx_options *mpxopt) ;
+int mpx_run_dvitomp (mpx_options *mpxopt) ;
+
+
+@
+
+@d ERRLOG "mpxerr.log"
+@d MPXLOG "makempx.log"
+
+@c
+int mpx_makempx (mpx_options *mpxopt) {
+ MPX mpx;
+ char **cmdline, **cmdbits;
+ char infile[15];
+ int retcode, i ;
+ char tmpname[] = "mpXXXXXX";
+ int cmdlength = 1;
+ int cmdbitlength = 1;
+ if (!mpxopt->debug) {
+ @<Check if mp file is newer than mpxfile, exit if not@>;
+ }
+ mpx = malloc(sizeof(struct mpx_data));
+ if (mpx==NULL || mpxopt->cmd==NULL || mpxopt->mpname==NULL || mpxopt->mpxname==NULL)
+ return mpx_fatal_error;
+ mpx_initialize(mpx);
+ if (mpxopt->banner!=NULL)
+ mpx->banner = mpxopt->banner;
+ mpx->mode = mpxopt->mode;
+ mpx->debug = mpxopt->debug;
+ if (mpxopt->find_file!=NULL)
+ mpx->find_file = mpxopt->find_file;
+ if (mpxopt->cmd!=NULL)
+ mpx->maincmd = xstrdup(mpxopt->cmd); /* valgrind says this leaks */
+ mpx->mpname = xstrdup(mpxopt->mpname);
+ mpx->mpxname = xstrdup(mpxopt->mpxname);
+ @<Install and test the non-local jump buffer@>;
+
+ if (mpx->debug) {
+ mpx->errfile = stderr;
+ } else {
+ mpx->errfile = mpx_xfopen(mpx,MPXLOG, "wb");
+ }
+ mpx->progname = "makempx";
+ @<Initialize the |tmpname| variable@>;
+ if (mpxopt->mptexpre == NULL)
+ mpxopt->mptexpre = xstrdup("mptexpre.tex");
+ @<Run |mpto| on the mp file@>;
+ if (mpxopt->cmd==NULL)
+ goto DONE;
+ if (mpx->mode == mpx_tex_mode) {
+ @<Run |TeX| and set up |infile| or abort@>;
+ if (mpx_dvitomp(mpx, infile)) {
+ mpx_rename(mpx, infile,DVIERR);
+ if (!mpx->debug)
+ remove(mpx->mpxname);
+ mpx_abort(mpx, "Dvi conversion failed: %s %s\n",
+ DVIERR, mpx->mpxname);
+ }
+ } else if (mpx->mode == mpx_troff_mode) {
+ @<Run |Troff| and set up |infile| or abort@>;
+ if (mpx_dmp(mpx, infile)) {
+ mpx_rename(mpx,infile, TROFF_OUTERR);
+ mpx_rename(mpx,mpx->tex, TROFF_INERR);
+ if (!mpx->debug)
+ remove(mpx->mpxname);
+ mpx_abort(mpx, "Troff conversion failed: %s %s\n",
+ TROFF_OUTERR, mpx->mpxname);
+ }
+ }
+ mpx_fclose(mpx,mpx->mpxfile);
+ if (!mpx->debug)
+ mpx_fclose(mpx,mpx->errfile);
+ if (!mpx->debug) {
+ remove(MPXLOG);
+ remove(ERRLOG);
+ remove(infile);
+ }
+ mpx_erasetmp(mpx);
+ DONE:
+ retcode = mpx->history;
+ mpx_xfree(mpx->buf);
+ mpx_xfree(mpx->maincmd);
+ for (i = 0; i < (int)mpx->nfonts; i++)
+ mpx_xfree(mpx->font_name[i]);
+ free(mpx);
+ if (retcode == mpx_cksum_trouble)
+ retcode = 0;
+ return retcode;
+}
+int mpx_run_dvitomp (mpx_options *mpxopt) {
+ MPX mpx;
+ int retcode, i ;
+ mpx = malloc(sizeof(struct mpx_data));
+ if (mpx==NULL || mpxopt->mpname==NULL || mpxopt->mpxname==NULL)
+ return mpx_fatal_error;
+ mpx_initialize(mpx);
+ if (mpxopt->banner!=NULL)
+ mpx->banner = mpxopt->banner;
+ mpx->mode = mpxopt->mode;
+ mpx->debug = mpxopt->debug;
+ if (mpxopt->find_file!=NULL)
+ mpx->find_file = mpxopt->find_file;
+ mpx->mpname = xstrdup(mpxopt->mpname);
+ mpx->mpxname = xstrdup(mpxopt->mpxname);
+ @<Install and test the non-local jump buffer@>;
+ if (mpx->debug) {
+ mpx->errfile = stderr;
+ } else {
+ mpx->errfile = mpx_xfopen(mpx,MPXLOG, "wb");
+ }
+ mpx->progname = "dvitomp";
+ if (mpx_dvitomp(mpx, mpx->mpname)) {
+ if (!mpx->debug)
+ remove(mpx->mpxname);
+ mpx_abort(mpx, "Dvi conversion failed: %s %s\n",
+ DVIERR, mpx->mpxname);
+ }
+ mpx_fclose(mpx,mpx->mpxfile);
+ if (!mpx->debug)
+ mpx_fclose(mpx,mpx->errfile);
+ if (!mpx->debug) {
+ remove(MPXLOG);
+ remove(ERRLOG);
+ }
+ mpx_erasetmp(mpx);
+ retcode = mpx->history;
+ mpx_xfree(mpx->buf);
+ for (i = 0; i < (int)mpx->nfonts; i++)
+ mpx_xfree(mpx->font_name[i]);
+ free(mpx);
+ if (retcode == mpx_cksum_trouble)
+ retcode = 0;
+ return retcode;
+}
+
+
+@ \TeX\ has to operate on an actual input file, so we have to append
+that to the command line.
+
+@<Run |TeX| and set ...@>=
+{
+ char log[15];
+ mpx->maincmd = xrealloc(mpx->maincmd,strlen(mpx->maincmd)+strlen(mpx->tex)+2,1);
+ strcat(mpx->maincmd, " ");
+ strcat(mpx->maincmd, mpx->tex);
+ cmdlength = split_command(mpx->maincmd, cmdline);
+
+ retcode = mpx_run_command(mpx, NULL, NULL, cmdlength, cmdline);
+
+ TMPNAME_EXT(log, ".log");
+ if (!retcode) {
+ TMPNAME_EXT(infile, ".dvi");
+ remove(log);
+ } else {
+ mpx_rename(mpx,mpx->tex, TEXERR);
+ mpx_rename(mpx,log, ERRLOG);
+ mpx_command_error(mpx, cmdlength, cmdline);
+ }
+ mpx_command_cleanup(mpx, cmdline);
+}
+
+@ @<Run |Troff| and set ...@>=
+{
+ char *cur_in, *cur_out;
+ char tmp_a[15], tmp_b[15];
+ TMPNAME_EXT(tmp_a, ".t");
+ TMPNAME_EXT(tmp_b, ".tmp");
+ cur_in = mpx->tex;
+ cur_out = tmp_a;
+
+ /* split the command in bits */
+ cmdbitlength = split_pipes(mpx->maincmd, cmdbits);
+
+ for (i = 0; i < cmdbitlength; i++) {
+ if (cmdline!=NULL) free(cmdline);
+ cmdlength = split_command(cmdbits[i], cmdline);
+ retcode = mpx_run_command(mpx, cur_in, cur_out, cmdlength, cmdline);
+
+ if (retcode) {
+ mpx_rename(mpx,mpx->tex, TROFF_INERR);
+ mpx_command_error(mpx, cmdlength, cmdline);
+ }
+ if (i < cmdbitlength - 1) {
+ if (i % 2 == 0) {
+ cur_in = tmp_a;
+ cur_out = tmp_b;
+ } else {
+ cur_in = tmp_b;
+ cur_out = tmp_a;
+ }
+ strcpy(infile,cur_in);
+ }
+ }
+ if (tmp_a!=infile) { remove(tmp_a); }
+ if (tmp_b!=infile) { remove(tmp_b); }
+}
+
+@ If MPX file is up-to-date or if MP file does not exist, do nothing.
+
+@<Check if mp file is newer than mpxfile, exit if not@>=
+if (mpx_newer(mpxopt->mpname, mpxopt->mpxname))
+ return 0
+
+
+@ The splint comment is here because this use of |sprintf()| is definately safe
+
+@<Initialize the |tmpname| variable@>=
+@= /*@@-bufferoverflowhigh@@*/ @>
+#ifdef HAVE_MKSTEMP
+ i = mkstemp(tmpname);
+ if (i == -1) {
+ sprintf(tmpname, "mp%06d", (int)(time(NULL) % 1000000));
+ } else {
+ close(i);
+ remove(tmpname);
+ }
+#else
+#ifdef HAVE_MKTEMP
+ {
+ char *tmpstring = mktemp(tmpname);
+ if ((tmpstring == NULL) || strlen(tmpname) == 0) {
+ sprintf(tmpname, "mp%06d", (int)(time(NULL) % 1000000));
+ } else {
+ /* this should not really be needed, but better
+ safe than sorry. */
+ if (tmpstring != tmpname) {
+ i = strlen(tmpstring);
+ if (i > 8) i = 8;
+ strncpy(tmpname, tmpstring, i);
+ }
+ }
+ }
+#else
+ sprintf(tmpname, "mp%06d", (int)(time(NULL) % 1000000));
+#endif
+#endif
+@= /*@@+bufferoverflowhigh@@*/ @>
diff --git a/Build/source/texk/web2c/mplibdir/psout.w b/Build/source/texk/web2c/mplibdir/psout.w
new file mode 100644
index 00000000000..90bc96a9aa3
--- /dev/null
+++ b/Build/source/texk/web2c/mplibdir/psout.w
@@ -0,0 +1,6246 @@
+% $Id: psout.w 878 2009-03-22 08:22:33Z taco $
+%
+% Copyright 2008 Taco Hoekwater.
+%
+% This program is free software: you can redistribute it and/or modify
+% it under the terms of the GNU Lesser General Public License as published by
+% the Free Software Foundation, either version 3 of the License, or
+% (at your option) any later version.
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+% GNU Lesser General Public License for more details.
+%
+% You should have received a copy of the GNU Lesser General Public License
+% along with this program. If not, see <http://www.gnu.org/licenses/>.
+%
+% TeX is a trademark of the American Mathematical Society.
+% METAFONT is a trademark of Addison-Wesley Publishing Company.
+% PostScript is a trademark of Adobe Systems Incorporated.
+
+% Here is TeX material that gets inserted after \input webmac
+\def\hang{\hangindent 3em\noindent\ignorespaces}
+\def\textindent#1{\hangindent2.5em\noindent\hbox to2.5em{\hss#1 }\ignorespaces}
+\def\PASCAL{Pascal}
+\def\ps{PostScript}
+\def\ph{\hbox{Pascal-H}}
+\def\psqrt#1{\sqrt{\mathstrut#1}}
+\def\k{_{k+1}}
+\def\pct!{{\char`\%}} % percent sign in ordinary text
+\font\tenlogo=logo10 % font used for the METAFONT logo
+\font\logos=logosl10
+\def\MF{{\tenlogo META}\-{\tenlogo FONT}}
+\def\MP{{\tenlogo META}\-{\tenlogo POST}}
+\def\<#1>{$\langle#1\rangle$}
+\def\section{\mathhexbox278}
+\let\swap=\leftrightarrow
+\def\round{\mathop{\rm round}\nolimits}
+\mathchardef\vbv="026A % synonym for `\|'
+\def\vb{\relax\ifmmode\vbv\else$\vbv$\fi}
+\def\[#1]{} % from pascal web
+\def\(#1){} % this is used to make section names sort themselves better
+\def\9#1{} % this is used for sort keys in the index via @@:sort key}{entry@@>
+
+\let\?=\relax % we want to be able to \write a \?
+
+\def\title{MetaPost \ps\ output}
+\def\topofcontents{\hsize 5.5in
+ \vglue -30pt plus 1fil minus 1.5in
+ \def\?##1]{\hbox to 1in{\hfil##1.\ }}
+ }
+\def\botofcontents{\vskip 0pt plus 1fil minus 1.5in}
+\pdfoutput=1
+\pageno=3
+
+@
+@d true 1
+@d false 0
+@d null_font 0
+@d null 0
+@d unity 0200000 /* $2^{16}$, represents 1.00000 */
+@d el_gordo 017777777777 /* $2^{31}-1$, the largest value that \MP\ likes */
+@d incr(A) (A)=(A)+1 /* increase a variable by unity */
+@d decr(A) (A)=(A)-1 /* decrease a variable by unity */
+@d negate(A) (A)=-(A) /* change the sign of a variable */
+@d odd(A) ((A)%2==1)
+@d half(A) ((A)/2)
+@d print_err(A) mp_print_err(mp,(A))
+@d max_quarterword 0x3FFF /* largest allowable value in a |quarterword| */
+
+@c
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <assert.h>
+#include "avl.h"
+#include "mplib.h"
+#include "mplibps.h" /* external header */
+#include "mpmp.h" /* internal header */
+#include "mppsout.h" /* internal header */
+@h
+@<Declarations@>
+@<Static variables in the outer block@>
+
+@ There is a small bit of code from the backend that bleads through
+to the frontend because I do not know how to set up the includes
+properly. That is the |typedef struct psout_data_struct * psout_data|.
+
+@ @(mppsout.h@>=
+#include "avl.h"
+@<Types...@>
+typedef struct psout_data_struct {
+ @<Globals@>
+} psout_data_struct ;
+@<Exported function headers@>
+
+@
+@c
+void *avl_probe (avl_tree t, void *p) {
+ int ret = avl_ins(p, t, false);
+ if (ret < 0)
+ return NULL;
+ else
+ return avl_find(p, t);
+}
+
+@ @<Exported...@>=
+void *avl_probe (avl_tree t, void *p) ;
+
+
+@ @c
+static boolean mp_isdigit (int a) {
+ return (a>='0'&&a<='9');
+}
+static int mp_tolower (int a) {
+ if (a>='A' && a <='Z')
+ return a - 'A' + 'a';
+ return a;
+}
+static int mp_strcasecmp (const char *s1, const char *s2) {
+ int r;
+ char *ss1, *ss2, *c;
+ ss1 = mp_strdup(s1);
+ c = ss1;
+ while (*c != '\0') {
+ *c = mp_tolower(*c); c++;
+ }
+ ss2 = mp_strdup(s2);
+ c = ss2;
+ while (*c != '\0') {
+ *c = mp_tolower(*c); c++;
+ }
+ r = strcmp(ss1,ss2);
+ free (ss1); free(ss2);
+ return r;
+}
+
+@ @<Exported function headers@>=
+void mp_ps_backend_initialize (MP mp) ;
+void mp_ps_backend_free (MP mp) ;
+
+@
+@c void mp_ps_backend_initialize (MP mp) {
+ mp->ps = mp_xmalloc(mp,1,sizeof(psout_data_struct));
+ @<Set initial values@>;
+}
+void mp_ps_backend_free (MP mp) {
+ @<Dealloc variables@>;
+ enc_free(mp);
+ t1_free(mp);
+ fm_free(mp);
+ mp_xfree(mp->ps);
+ mp->ps = NULL;
+}
+
+@ Writing to ps files
+
+@<Globals@>=
+integer ps_offset;
+ /* the number of characters on the current \ps\ file line */
+
+@ @<Set initial values@>=
+mp->ps->ps_offset = 0;
+
+@
+
+@d wps(A) (mp->write_ascii_file)(mp,mp->output_file,(A))
+@d wps_chr(A) do {
+ char ss[2];
+ ss[0]=(A); ss[1]=0;
+ (mp->write_ascii_file)(mp,mp->output_file,(char *)ss);
+} while (0)
+@d wps_cr (mp->write_ascii_file)(mp,mp->output_file,"\n")
+@d wps_ln(A) { wterm_cr; (mp->write_ascii_file)(mp,mp->output_file,(A)); }
+
+@c
+static void mp_ps_print_ln (MP mp) { /* prints an end-of-line */
+ wps_cr;
+ mp->ps->ps_offset=0;
+}
+
+@ @c
+static void mp_ps_print_char (MP mp, int s) { /* prints a single character */
+ if ( s==13 ) {
+ wps_cr; mp->ps->ps_offset=0;
+ } else {
+ wps_chr(s); incr(mp->ps->ps_offset);
+ }
+}
+
+@ @c
+static void mp_ps_do_print (MP mp, const char *ss, size_t len) { /* prints string |s| */
+ size_t j = 0;
+ while ( j<len ){
+ mp_ps_print_char(mp, ss[j]); incr(j);
+ }
+}
+
+@ Deciding where to break the ps output line.
+
+@d ps_room(A) if (mp->ps->ps_offset>0 && (mp->ps->ps_offset+(int)(A))>mp->max_print_line ) {
+ mp_ps_print_ln(mp); /* optional line break */
+}
+
+@c
+static void mp_ps_print (MP mp, const char *ss) {
+ ps_room(strlen(ss));
+ mp_ps_do_print(mp, ss, strlen(ss));
+}
+
+@ The procedure |print_nl| is like |print|, but it makes sure that the
+string appears at the beginning of a new line.
+
+@c
+static void mp_ps_print_nl (MP mp, const char *s) { /* prints string |s| at beginning of line */
+ if ( mp->ps->ps_offset>0 ) mp_ps_print_ln(mp);
+ mp_ps_print(mp, s);
+}
+
+@ An array of digits in the range |0..9| is printed by |print_the_digs|.
+
+@c
+static void mp_ps_print_the_digs (MP mp, int k) {
+ /* prints |dig[k-1]|$\,\ldots\,$|dig[0]| */
+ while ( k-->0 ){
+ mp_ps_print_char(mp, '0'+mp->dig[k]);
+ }
+}
+
+@ The following procedure, which prints out the decimal representation of a
+given integer |n|, has been written carefully so that it works properly
+if |n=0| or if |(-n)| would cause overflow. It does not apply |mod| or |div|
+to negative arguments, since such operations are not implemented consistently
+by all \PASCAL\ compilers.
+
+@c
+static void mp_ps_print_int (MP mp,integer n) { /* prints an integer in decimal form */
+ integer m; /* used to negate |n| in possibly dangerous cases */
+ int k = 0; /* index to current digit; we assume that $|n|<10^{23}$ */
+ if ( n<0 ) {
+ mp_ps_print_char(mp, '-');
+ if ( n>-100000000 ) {
+ negate(n);
+ } else {
+ m=-1-n; n=m / 10; m=(m % 10)+1; k=1;
+ if ( m<10 ) {
+ mp->dig[0]=(unsigned char)m;
+ } else {
+ mp->dig[0]=0; incr(n);
+ }
+ }
+ }
+ do {
+ mp->dig[k]=(unsigned char)(n % 10); n=n / 10; incr(k);
+ } while (n!=0);
+ mp_ps_print_the_digs(mp, k);
+}
+
+@ \MP\ also makes use of a trivial procedure to print two digits. The
+following subroutine is usually called with a parameter in the range |0<=n<=99|.
+
+@c
+static void mp_ps_print_dd (MP mp,integer n) { /* prints two least significant digits */
+ n=abs(n) % 100;
+ mp_ps_print_char(mp, '0'+(n / 10));
+ mp_ps_print_char(mp, '0'+(n % 10));
+}
+
+@ Conversely, here is a procedure analogous to |print_int|. If the output
+of this procedure is subsequently read by \MP\ and converted by the
+|round_decimals| routine above, it turns out that the original value will
+be reproduced exactly. A decimal point is printed only if the value is
+not an integer. If there is more than one way to print the result with
+the optimum number of digits following the decimal point, the closest
+possible value is given.
+
+The invariant relation in the \&{repeat} loop is that a sequence of
+decimal digits yet to be printed will yield the original number if and only if
+they form a fraction~$f$ in the range $s-\delta\L10\cdot2^{16}f<s$.
+We can stop if and only if $f=0$ satisfies this condition; the loop will
+terminate before $s$ can possibly become zero.
+
+@c
+static void mp_ps_print_scaled (MP mp,scaled s) {
+ scaled delta; /* amount of allowable inaccuracy */
+ if ( s<0 ) {
+ mp_ps_print_char(mp, '-');
+ negate(s); /* print the sign, if negative */
+ }
+ mp_ps_print_int(mp, s / unity); /* print the integer part */
+ s=10*(s % unity)+5;
+ if ( s!=5 ) {
+ delta=10;
+ mp_ps_print_char(mp, '.');
+ do {
+ if ( delta>unity )
+ s=s+0100000-(delta / 2); /* round the final digit */
+ mp_ps_print_char(mp, '0'+(s / unity));
+ s=10*(s % unity);
+ delta=delta*10;
+ } while (s>delta);
+ }
+}
+
+
+@* \[44a] Dealing with font encodings.
+
+First, here are a few helpers for parsing files
+
+@d check_buf(size, buf_size)
+ if ((unsigned)(size) > (unsigned)(buf_size)) {
+ char S[128];
+ mp_snprintf(S,128,"buffer overflow: (%u,%u) at file %s, line %d",
+ (unsigned)(size),(unsigned)(buf_size), __FILE__, __LINE__ );
+ mp_fatal_error(mp,S);
+ }
+
+@d append_char_to_buf(c, p, buf, buf_size) do {
+ if (c == 9)
+ c = 32;
+ if (c == 13 || c == EOF)
+ c = 10;
+ if (c != ' ' || (p > buf && p[-1] != 32)) {
+ check_buf(p - buf + 1, (buf_size));
+ *p++ = c;
+ }
+} while (0)
+
+@d append_eol(p, buf, buf_size) do {
+ check_buf(p - buf + 2, (buf_size));
+ if (p - buf > 1 && p[-1] != 10)
+ *p++ = 10;
+ if (p - buf > 2 && p[-2] == 32) {
+ p[-2] = 10;
+ p--;
+ }
+ *p = 0;
+} while (0)
+
+@d remove_eol(p, buf) do {
+ p = strend(buf) - 1;
+ if (*p == 10)
+ *p = 0;
+} while (0)
+
+@d skip(p, c) if (*p == c) p++
+@d strend(s) strchr(s, 0)
+@d str_prefix(s1, s2) (strncmp((s1), (s2), strlen(s2)) == 0)
+
+
+@ @<Types...@>=
+typedef struct {
+ boolean loaded; /* the encoding has been loaded? */
+ char *file_name; /* encoding file name */
+ char *enc_name; /* encoding true name */
+ integer objnum; /* object number */
+ char **glyph_names;
+ integer tounicode; /* object number of associated ToUnicode entry */
+} enc_entry;
+
+
+@
+
+@d ENC_STANDARD 0
+@d ENC_BUILTIN 1
+
+@<Glob...@>=
+#define ENC_BUF_SIZE 0x1000
+char enc_line[ENC_BUF_SIZE];
+void * enc_file;
+
+@
+@d enc_eof() (mp->eof_file)(mp,mp->ps->enc_file)
+@d enc_close() (mp->close_file)(mp,mp->ps->enc_file)
+
+@c
+static int enc_getchar(MP mp) {
+ size_t len = 1;
+ unsigned char abyte=0;
+ void *byte_ptr = &abyte;
+ (mp->read_binary_file)(mp,mp->ps->enc_file,&byte_ptr,&len);
+ return abyte;
+}
+
+@ @c
+static boolean mp_enc_open (MP mp, char *n) {
+ mp->ps->enc_file=(mp->open_file)(mp,n, "r", mp_filetype_encoding);
+ if (mp->ps->enc_file!=NULL)
+ return true;
+ else
+ return false;
+}
+static void mp_enc_getline (MP mp) {
+ char *p;
+ int c;
+RESTART:
+ if (enc_eof ()) {
+ print_err("unexpected end of file");
+ mp_error(mp);
+ }
+ p = mp->ps->enc_line;
+ do {
+ c = enc_getchar (mp);
+ append_char_to_buf (c, p, mp->ps->enc_line, ENC_BUF_SIZE);
+ } while (c != 10);
+ append_eol (p, mp->ps->enc_line, ENC_BUF_SIZE);
+ if (p - mp->ps->enc_line < 2 || *mp->ps->enc_line == '%')
+ goto RESTART;
+}
+static void mp_load_enc (MP mp, char *enc_name,
+ char **enc_encname, char **glyph_names){
+ char buf[ENC_BUF_SIZE], *p, *r;
+ int names_count;
+ char *myname;
+ unsigned save_selector = mp->selector;
+ if (!mp_enc_open (mp,enc_name)) {
+ mp_print (mp,"cannot open encoding file for reading");
+ return;
+ }
+ mp_normalize_selector(mp);
+ mp_print (mp,"{");
+ mp_print (mp, enc_name);
+ mp_enc_getline (mp);
+ if (*mp->ps->enc_line != '/' || (r = strchr (mp->ps->enc_line, '[')) == NULL) {
+ remove_eol (r, mp->ps->enc_line);
+ print_err ("invalid encoding vector (a name or `[' missing): `");
+ mp_print(mp,mp->ps->enc_line);
+ mp_print(mp,"'");
+ mp_error(mp);
+ }
+ while (*(r-1)==' ') r--; /* strip trailing spaces from encoding name */
+ myname = mp_xmalloc(mp,r-mp->ps->enc_line,1);
+ memcpy(myname,mp->ps->enc_line+1,(r-mp->ps->enc_line)-1);
+ *(myname+(r-mp->ps->enc_line-1))=0;
+ *enc_encname = myname;
+ while (*r!='[') r++;
+ r++; /* skip '[' */
+ names_count = 0;
+ skip (r, ' ');
+ for (;;) {
+ while (*r == '/') {
+ for (p = buf, r++;
+ *r != ' ' && *r != 10 && *r != ']' && *r != '/'; *p++ = *r++);
+ *p = 0;
+ skip (r, ' ');
+ if (names_count > 256) {
+ print_err ("encoding vector contains more than 256 names");
+ mp_error(mp);
+ }
+ if (mp_xstrcmp (buf, notdef) != 0)
+ glyph_names[names_count] = mp_xstrdup (mp,buf);
+ names_count++;
+ }
+ if (*r != 10 && *r != '%') {
+ if (str_prefix (r, "] def"))
+ goto DONE;
+ else {
+ remove_eol (r, mp->ps->enc_line);
+ print_err
+ ("invalid encoding vector: a name or `] def' expected: `");
+ mp_print(mp,mp->ps->enc_line);
+ mp_print(mp,"'");
+ mp_error(mp);
+ }
+ }
+ mp_enc_getline (mp);
+ r = mp->ps->enc_line;
+ }
+DONE:
+ enc_close ();
+ mp_print (mp,"}");
+ mp->selector = save_selector;
+}
+static void mp_read_enc (MP mp, enc_entry * e) {
+ if (e->loaded)
+ return;
+ e->enc_name = NULL;
+ mp_load_enc (mp,e->file_name, &e->enc_name, e->glyph_names);
+ e->loaded = true;
+}
+
+@ |write_enc| is used to write either external encoding (given in map file) or
+ internal encoding (read from the font file);
+ the 2nd argument is a pointer to the encoding entry;
+
+@c
+static void mp_write_enc (MP mp, enc_entry * e) {
+ int i;
+ size_t s, foffset;
+ char **g;
+ if (e->objnum != 0) /* the encoding has been written already */
+ return;
+ e->objnum = 1;
+ g = e->glyph_names;
+
+ mp_ps_print(mp,"\n%%%%BeginResource: encoding ");
+ mp_ps_print(mp, e->enc_name);
+ mp_ps_print_nl(mp, "/");
+ mp_ps_print(mp, e->enc_name);
+ mp_ps_print(mp, " [ ");
+ mp_ps_print_ln (mp);
+ foffset = strlen(e->file_name)+3;
+ for (i = 0; i < 256; i++) {
+ s = strlen(g[i]);
+ if (s+1+foffset>=80) {
+ mp_ps_print_ln (mp);
+ foffset = 0;
+ }
+ foffset += s+2;
+ mp_ps_print_char(mp,'/');
+ mp_ps_print(mp, g[i]);
+ mp_ps_print_char(mp,' ');
+ }
+ if (foffset>75)
+ mp_ps_print_ln (mp);
+ mp_ps_print_nl (mp,"] def\n");
+ mp_ps_print(mp,"%%%%EndResource");
+}
+
+
+@ All encoding entries go into AVL tree for fast search by name.
+
+@<Glob...@>=
+avl_tree enc_tree;
+
+@
+
+@<Static variables in the outer block@>=
+static const char notdef[] = ".notdef";
+
+@ @<Set initial...@>=
+mp->ps->enc_tree = NULL;
+
+@ @c
+static int comp_enc_entry (void *p, const void *pa, const void *pb) {
+ (void)p;
+ return strcmp (((const enc_entry *) pa)->file_name,
+ ((const enc_entry *) pb)->file_name);
+}
+static void *destroy_enc_entry (void *pa) {
+ enc_entry *p;
+ int i;
+ p = (enc_entry *) pa;
+ mp_xfree (p->file_name);
+ if (p->glyph_names != NULL)
+ for (i = 0; i < 256; i++)
+ if (p->glyph_names[i] != notdef)
+ mp_xfree (p->glyph_names[i]);
+ mp_xfree (p->glyph_names);
+ mp_xfree (p);
+}
+static void *copy_enc_entry (const void *pa) {
+ enc_entry *p, *q;
+ int i;
+ p = (enc_entry *) pa;
+ q = malloc (sizeof (enc_entry));
+ if (q!=NULL) {
+ q->loaded = p->loaded;
+ q->file_name = strdup (p->file_name);
+ q->objnum = p->objnum;
+ q->tounicode = p->tounicode;
+ q->glyph_names = malloc (256 * sizeof (char *));
+ if (p->glyph_names == NULL)
+ return NULL;
+ for (i = 0; i < 256; i++) {
+ if (p->glyph_names[i]!=NULL)
+ q->glyph_names[i] = strdup(p->glyph_names[i]);
+ else
+ q->glyph_names[i] = NULL;
+ }
+ }
+ return (void *)q;
+}
+
+static enc_entry * mp_add_enc (MP mp, char *s) {
+ int i;
+ enc_entry tmp, *p;
+ void **aa;
+ if (mp->ps->enc_tree == NULL) {
+ mp->ps->enc_tree = avl_create (comp_enc_entry,
+ copy_enc_entry,
+ destroy_enc_entry,
+ malloc, free, NULL);
+ }
+ tmp.file_name = s;
+ p = (enc_entry *) avl_find (&tmp, mp->ps->enc_tree);
+ if (p != NULL) /* encoding already registered */
+ return p;
+ p = mp_xmalloc (mp,1,sizeof (enc_entry));
+ p->loaded = false;
+ p->file_name = mp_xstrdup (mp,s);
+ p->objnum = 0;
+ p->tounicode = 0;
+ p->glyph_names = mp_xmalloc (mp,256,sizeof (char *));
+ for (i = 0; i < 256; i++)
+ p->glyph_names[i] = (char *) notdef;
+ aa = avl_probe (mp->ps->enc_tree, p);
+ return p;
+}
+
+@ cleaning up...
+
+
+@ @<Declarations@>=
+static void enc_free (MP mp);
+
+@ @c static void enc_free (MP mp) {
+ if (mp->ps->enc_tree != NULL)
+ avl_destroy (mp->ps->enc_tree);
+}
+
+@ @<Declarations@>=
+static void mp_reload_encodings (MP mp) ;
+static void mp_font_encodings (MP mp, font_number lastfnum, boolean encodings_only) ;
+
+@ @c void mp_reload_encodings (MP mp) {
+ font_number f;
+ enc_entry *e;
+ fm_entry *fm_cur;
+ font_number lastfnum = mp->last_fnum;
+ for (f=null_font+1;f<=lastfnum;f++) {
+ if (mp->font_enc_name[f]!=NULL ) {
+ mp_xfree(mp->font_enc_name[f]);
+ mp->font_enc_name[f]=NULL;
+ }
+ if (mp_has_fm_entry (mp,f,&fm_cur)) {
+ if (fm_cur != NULL && fm_cur->ps_name != NULL &&is_reencoded (fm_cur)) {
+ e = fm_cur->encoding;
+ mp_read_enc (mp,e);
+ }
+ }
+ }
+}
+static void mp_font_encodings (MP mp, font_number lastfnum, boolean encodings_only) {
+ font_number f;
+ enc_entry *e;
+ fm_entry *fm;
+ for (f=null_font+1;f<=lastfnum;f++) {
+ if (mp_has_font_size(mp,f) && mp_has_fm_entry (mp,f, &fm)) {
+ if (fm != NULL && (fm->ps_name != NULL)) {
+ if (is_reencoded (fm)) {
+ if (encodings_only || (!is_subsetted (fm))) {
+ e = fm->encoding;
+ mp_write_enc (mp, e);
+ /* clear for next run */
+ e->objnum = 0;
+ }
+ }
+ }
+ }
+ }
+}
+
+@* \[44b] Parsing font map files.
+
+@d FM_BUF_SIZE 1024
+
+@<Glob...@>=
+void * fm_file;
+
+@
+@d fm_close() (mp->close_file)(mp,mp->ps->fm_file)
+@d fm_eof() (mp->eof_file)(mp,mp->ps->fm_file)
+
+@c
+static int fm_getchar(MP mp) {
+ size_t len = 1;
+ unsigned char abyte=0;
+ void *byte_ptr = &abyte;
+ (mp->read_binary_file)(mp,mp->ps->fm_file,&byte_ptr,&len);
+ if (len==0)
+ return EOF;
+ return abyte;
+}
+
+
+@ @<Types...@>=
+enum _mode { FM_DUPIGNORE, FM_REPLACE, FM_DELETE };
+enum _ltype { MAPFILE, MAPLINE };
+enum _tfmavail { TFM_UNCHECKED, TFM_FOUND, TFM_NOTFOUND };
+typedef struct mitem {
+ int mode; /* |FM_DUPIGNORE| or |FM_REPLACE| or |FM_DELETE| */
+ int type; /* map file or map line */
+ char *map_line; /* pointer to map file name or map line */
+ int lineno; /* line number in map file */
+} mapitem;
+
+@ @<Glob...@>=
+mapitem *mitem;
+fm_entry *fm_cur;
+fm_entry *loaded_tfm_found;
+fm_entry *avail_tfm_found;
+fm_entry *non_tfm_found;
+fm_entry *not_avail_tfm_found;
+
+@ @<Set initial...@>=
+mp->ps->mitem = NULL;
+
+@ @<Declarations@>=
+static const char nontfm[] = "<nontfm>";
+
+@
+@d read_field(r, q, buf) do {
+ q = buf;
+ while (*r != ' ' && *r != '\0')
+ *q++ = *r++;
+ *q = '\0';
+ skip (r, ' ');
+} while (0)
+
+@d set_field(F) do {
+ if (q > buf)
+ fm->F = mp_xstrdup(mp,buf);
+ if (*r == '\0')
+ goto DONE;
+} while (0)
+
+@d cmp_return(a, b)
+ if (a > b)
+ return 1;
+ if (a < b)
+ return -1
+
+@d do_strdup(a) (a==NULL ? NULL : strdup(a))
+
+@c
+static fm_entry *new_fm_entry (MP mp) {
+ fm_entry *fm;
+ fm = mp_xmalloc (mp,1,sizeof(fm_entry));
+ fm->tfm_name = NULL;
+ fm->ps_name = NULL;
+ fm->flags = 4;
+ fm->ff_name = NULL;
+ fm->subset_tag = NULL;
+ fm->encoding = NULL;
+ fm->tfm_num = null_font;
+ fm->tfm_avail = TFM_UNCHECKED;
+ fm->type = 0;
+ fm->slant = 0;
+ fm->extend = 0;
+ fm->ff_objnum = 0;
+ fm->fn_objnum = 0;
+ fm->fd_objnum = 0;
+ fm->charset = NULL;
+ fm->all_glyphs = false;
+ fm->links = 0;
+ fm->pid = -1;
+ fm->eid = -1;
+ return fm;
+}
+
+static void *copy_fm_entry (const void *p) {
+ fm_entry *fm, *fp;
+ fp = (fm_entry *)p;
+ fm = malloc (sizeof(fm_entry));
+ if (fm==NULL)
+ return NULL;
+ memcpy(fm, fp, sizeof(fm_entry));
+ fm->tfm_name = do_strdup(fp->tfm_name);
+ fm->ps_name = do_strdup(fp->ps_name);
+ fm->ff_name = do_strdup(fp->ff_name);
+ fm->subset_tag = do_strdup(fp->subset_tag);
+ fm->charset = do_strdup(fp->charset);
+ return (void *)fm;
+}
+
+
+static void * delete_fm_entry (void *p) {
+ fm_entry *fm = (fm_entry *)p;
+ mp_xfree (fm->tfm_name);
+ mp_xfree (fm->ps_name);
+ mp_xfree (fm->ff_name);
+ mp_xfree (fm->subset_tag);
+ mp_xfree (fm->charset);
+ mp_xfree (fm);
+}
+
+static ff_entry *new_ff_entry (MP mp) {
+ ff_entry *ff;
+ ff = mp_xmalloc (mp,1,sizeof(ff_entry));
+ ff->ff_name = NULL;
+ ff->ff_path = NULL;
+ return ff;
+}
+
+static void *copy_ff_entry (const void *p) {
+ ff_entry *ff, *fp;
+ fp = (ff_entry *)p;
+ ff = (ff_entry *)malloc (sizeof(ff_entry));
+ if (ff == NULL)
+ return NULL;
+ ff->ff_name = do_strdup(fp->ff_name);
+ ff->ff_path = do_strdup(fp->ff_path);
+ return ff;
+}
+
+static void * delete_ff_entry (void *p) {
+ ff_entry *ff = (ff_entry *)p;
+ mp_xfree (ff->ff_name);
+ mp_xfree (ff->ff_path);
+ mp_xfree (ff);
+}
+
+static char *mk_base_tfm (MP mp, char *tfmname, int *i) {
+ static char buf[SMALL_BUF_SIZE];
+ char *p = tfmname, *r = strend (p) - 1, *q = r;
+ while (q > p && mp_isdigit (*q))
+ --q;
+ if (!(q > p) || q == r || (*q != '+' && *q != '-'))
+ return NULL;
+ check_buf (q - p + 1, SMALL_BUF_SIZE);
+ strncpy (buf, p, (size_t) (q - p));
+ buf[q - p] = '\0';
+ *i = atoi (q);
+ return buf;
+}
+
+@ @<Declarations@>=
+static boolean mp_has_fm_entry (MP mp,font_number f, fm_entry **fm);
+
+@ @c
+boolean mp_has_fm_entry (MP mp,font_number f, fm_entry **fm) {
+ fm_entry *res = NULL;
+ res = mp_fm_lookup (mp, f);
+ if (fm != NULL) {
+ *fm =res;
+ }
+ return (res != NULL);
+}
+
+@ @<Glob...@>=
+avl_tree tfm_tree;
+avl_tree ps_tree;
+avl_tree ff_tree;
+
+@ @<Set initial...@>=
+mp->ps->tfm_tree = NULL;
+mp->ps->ps_tree = NULL;
+mp->ps->ff_tree = NULL;
+
+@ AVL sort |fm_entry| into |tfm_tree| by |tfm_name |
+
+@c
+static int comp_fm_entry_tfm (void *p, const void *pa, const void *pb) {
+ (void)p;
+ return strcmp (((const fm_entry *) pa)->tfm_name,
+ ((const fm_entry *) pb)->tfm_name);
+}
+
+@ AVL sort |fm_entry| into |ps_tree| by |ps_name|, |slant|, and |extend|
+
+@c static int comp_fm_entry_ps (void *p, const void *pa, const void *pb) {
+ int i;
+ const fm_entry *p1 = (const fm_entry *) pa;
+ const fm_entry *p2 = (const fm_entry *) pb;
+ (void)p;
+ assert (p1->ps_name != NULL && p2->ps_name != NULL);
+ if ((i = strcmp (p1->ps_name, p2->ps_name)))
+ return i;
+ cmp_return (p1->slant, p2->slant);
+ cmp_return (p1->extend, p2->extend);
+ if (p1->tfm_name != NULL && p2->tfm_name != NULL &&
+ (i = strcmp (p1->tfm_name, p2->tfm_name)))
+ return i;
+ return 0;
+}
+
+@ AVL sort |ff_entry| into |ff_tree| by |ff_name|
+
+@c static int comp_ff_entry (void *p, const void *pa, const void *pb) {
+ (void)p;
+ return strcmp (((const ff_entry *) pa)->ff_name,
+ ((const ff_entry *) pb)->ff_name);
+}
+
+@ @c static void create_avl_trees (MP mp) {
+ if (mp->ps->tfm_tree == NULL) {
+ mp->ps->tfm_tree = avl_create (comp_fm_entry_tfm,
+ copy_fm_entry,
+ delete_fm_entry,
+ malloc, free, NULL);
+ assert (mp->ps->tfm_tree != NULL);
+ }
+ if (mp->ps->ps_tree == NULL) {
+ mp->ps->ps_tree = avl_create (comp_fm_entry_ps,
+ copy_fm_entry,
+ delete_fm_entry,
+ malloc, free, NULL);
+ assert (mp->ps->ps_tree != NULL);
+ }
+ if (mp->ps->ff_tree == NULL) {
+ mp->ps->ff_tree = avl_create (comp_ff_entry,
+ copy_ff_entry,
+ delete_ff_entry,
+ malloc, free, NULL);
+ assert (mp->ps->ff_tree != NULL);
+ }
+}
+
+@ The function |avl_do_entry| is not completely symmetrical with regards
+to |tfm_name| and |ps_name handling|, e. g. a duplicate |tfm_name| gives a
+|goto exit|, and no |ps_name| link is tried. This is to keep it compatible
+with the original version.
+
+@d LINK_TFM 0x01
+@d LINK_PS 0x02
+@d set_tfmlink(fm) ((fm)->links |= LINK_TFM)
+@d set_pslink(fm) ((fm)->links |= LINK_PS)
+@d unset_tfmlink(fm) ((fm)->links &= ~LINK_TFM)
+@d unset_pslink(fm) ((fm)->links &= ~LINK_PS)
+@d has_tfmlink(fm) ((fm)->links & LINK_TFM)
+@d has_pslink(fm) ((fm)->links & LINK_PS)
+
+@c
+static int avl_do_entry (MP mp, fm_entry * fp, int mode) {
+ fm_entry *p;
+ void *a;
+ void **aa;
+ char s[128];
+
+ /* handle |tfm_name| link */
+
+ if (strcmp (fp->tfm_name, nontfm)) {
+ p = (fm_entry *) avl_find (fp, mp->ps->tfm_tree);
+ if (p != NULL) {
+ if (mode == FM_DUPIGNORE) {
+ mp_snprintf(s,128,"fontmap entry for `%s' already exists, duplicates ignored",
+ fp->tfm_name);
+ mp_warn(mp,s);
+ goto exit;
+ } else { /* mode == |FM_REPLACE| / |FM_DELETE| */
+ if (mp_has_font_size(mp,p->tfm_num)) {
+ mp_snprintf(s,128,
+ "fontmap entry for `%s' has been used, replace/delete not allowed",
+ fp->tfm_name);
+ mp_warn(mp,s);
+ goto exit;
+ }
+ (void) avl_del (p,mp->ps->tfm_tree,&a);
+ assert (a != NULL);
+ unset_tfmlink (p);
+ if (!has_pslink (p))
+ delete_fm_entry (p);
+ }
+ }
+ if (mode != FM_DELETE) {
+ aa = avl_probe (mp->ps->tfm_tree, fp);
+ assert (aa != NULL);
+ set_tfmlink (fp);
+ }
+ }
+
+ /* handle |ps_name| link */
+
+ if (fp->ps_name != NULL) {
+ assert (fp->tfm_name != NULL);
+ p = (fm_entry *) avl_find (fp, mp->ps->ps_tree);
+ if (p != NULL) {
+ if (mode == FM_DUPIGNORE) {
+ mp_snprintf(s,128,
+ "ps_name entry for `%s' already exists, duplicates ignored",
+ fp->ps_name);
+ mp_warn(mp,s);
+ goto exit;
+ } else { /* mode == |FM_REPLACE| / |FM_DELETE| */
+ if (mp_has_font_size(mp,p->tfm_num)) {
+ /* REPLACE/DELETE not allowed */
+ mp_snprintf(s,128,
+ "fontmap entry for `%s' has been used, replace/delete not allowed",
+ p->tfm_name);
+ mp_warn(mp,s);
+ goto exit;
+ }
+ (void)avl_del (p,mp->ps->ps_tree,&a);
+ assert (a != NULL);
+ unset_pslink (p);
+ if (!has_tfmlink (p))
+ delete_fm_entry (p);
+ }
+ }
+ if (mode != FM_DELETE) {
+ aa = avl_probe (mp->ps->ps_tree, fp);
+ assert (aa != NULL);
+ set_pslink (fp);
+ }
+ }
+ exit:
+ if (!has_tfmlink (fp) && !has_pslink (fp)) /* e. g. after |FM_DELETE| */
+ return 1; /* deallocation of |fm_entry| structure required */
+ else
+ return 0;
+}
+
+@ consistency check for map entry, with warn flag
+
+@c
+static int check_fm_entry (MP mp, fm_entry * fm, boolean warn) {
+ int a = 0;
+ char s[128];
+ assert (fm != NULL);
+ if (fm->ps_name != NULL) {
+ if (is_basefont (fm)) {
+ if (is_fontfile (fm) && !is_included (fm)) {
+ if (warn) {
+ mp_snprintf(s,128, "invalid entry for `%s': "
+ "font file must be included or omitted for base fonts",
+ fm->tfm_name);
+ mp_warn(mp,s);
+ }
+ a += 1;
+ }
+ } else { /* not a base font */
+ /* if no font file given, drop this entry */
+ /* |if (!is_fontfile (fm)) {
+ if (warn) {
+ mp_snprintf(s,128,
+ "invalid entry for `%s': font file missing",
+ fm->tfm_name);
+ mp_warn(mp,s);
+ }
+ a += 2;
+ }|
+ */
+ }
+ }
+ if (is_truetype (fm) && is_reencoded (fm) && !is_subsetted (fm)) {
+ if (warn) {
+ mp_snprintf(s,128,
+ "invalid entry for `%s': only subsetted TrueType font can be reencoded",
+ fm->tfm_name);
+ mp_warn(mp,s);
+ }
+ a += 4;
+ }
+ if ((fm->slant != 0 || fm->extend != 0) &&
+ (is_truetype (fm))) {
+ if (warn) {
+ mp_snprintf(s,128,
+ "invalid entry for `%s': "
+ "SlantFont/ExtendFont can be used only with embedded T1 fonts",
+ fm->tfm_name);
+ mp_warn(mp,s);
+ }
+ a += 8;
+ }
+ if (abs (fm->slant) > 1000) {
+ if (warn) {
+ mp_snprintf(s,128,
+ "invalid entry for `%s': too big value of SlantFont (%d/1000.0)",
+ fm->tfm_name, (int)fm->slant);
+ mp_warn(mp,s);
+ }
+ a += 16;
+ }
+ if (abs (fm->extend) > 2000) {
+ if (warn) {
+ mp_snprintf(s,128,
+ "invalid entry for `%s': too big value of ExtendFont (%d/1000.0)",
+ fm->tfm_name, (int)fm->extend);
+ mp_warn(mp,s);
+ }
+ a += 32;
+ }
+ if (fm->pid != -1 &&
+ !(is_truetype (fm) && is_included (fm) &&
+ is_subsetted (fm) && !is_reencoded (fm))) {
+ if (warn) {
+ mp_snprintf(s,128,
+ "invalid entry for `%s': "
+ "PidEid can be used only with subsetted non-reencoded TrueType fonts",
+ fm->tfm_name);
+ mp_warn(mp,s);
+ }
+ a += 64;
+ }
+ return a;
+}
+
+@ returns true if s is one of the 14 std. font names; speed-trimmed.
+
+@c static boolean check_basefont (char *s) {
+ static const char *basefont_names[] = {
+ "Courier", /* 0:7 */
+ "Courier-Bold", /* 1:12 */
+ "Courier-Oblique", /* 2:15 */
+ "Courier-BoldOblique", /* 3:19 */
+ "Helvetica", /* 4:9 */
+ "Helvetica-Bold", /* 5:14 */
+ "Helvetica-Oblique", /* 6:17 */
+ "Helvetica-BoldOblique", /* 7:21 */
+ "Symbol", /* 8:6 */
+ "Times-Roman", /* 9:11 */
+ "Times-Bold", /* 10:10 */
+ "Times-Italic", /* 11:12 */
+ "Times-BoldItalic", /* 12:16 */
+ "ZapfDingbats" /* 13:12 */
+ };
+ static const int Index[] =
+ { -1, -1, -1, -1, -1, -1, 8, 0, -1, 4, 10, 9, -1, -1, 5, 2, 12, 6,
+ -1, 3, -1, 7
+ };
+ const size_t n = strlen (s);
+ int k = -1;
+ if (n > 21)
+ return false;
+ if (n == 12) { /* three names have length 12 */
+ switch (*s) {
+ case 'C':
+ k = 1; /* Courier-Bold */
+ break;
+ case 'T':
+ k = 11; /* Times-Italic */
+ break;
+ case 'Z':
+ k = 13; /* ZapfDingbats */
+ break;
+ default:
+ return false;
+ }
+ } else
+ k = Index[n];
+ if (k > -1 && !strcmp (basefont_names[k], s))
+ return true;
+ return false;
+}
+
+@
+@d is_cfg_comment(c) (c == 10 || c == '*' || c == '#' || c == ';' || c == '%')
+
+@c static void fm_scan_line (MP mp) {
+ int a, b, c, j, u = 0, v = 0;
+ float d;
+ fm_entry *fm;
+ char fm_line[FM_BUF_SIZE], buf[FM_BUF_SIZE];
+ char *p, *q, *r, *s;
+ char warn_s[128];
+ switch (mp->ps->mitem->type) {
+ case MAPFILE:
+ p = fm_line;
+ do {
+ c = fm_getchar (mp);
+ append_char_to_buf (c, p, fm_line, FM_BUF_SIZE);
+ } while (c != 10);
+ *(--p) = '\0';
+ r = fm_line;
+ break;
+ case MAPLINE:
+ r = mp->ps->mitem->map_line;
+ break;
+ default:
+ assert (0);
+ }
+ if (*r == '\0' || is_cfg_comment (*r))
+ return;
+ fm = new_fm_entry (mp);
+ read_field (r, q, buf);
+ set_field (tfm_name);
+ p = r;
+ read_field (r, q, buf);
+ if (*buf != '<' && *buf != '"')
+ set_field (ps_name);
+ else
+ r = p; /* unget the field */
+ if (mp_isdigit (*r)) { /* font flags given */
+ fm->flags = atoi (r);
+ while (mp_isdigit (*r))
+ r++;
+ }
+ while (1) { /* loop through "specials", encoding, font file */
+ skip (r, ' ');
+ switch (*r) {
+ case '\0':
+ goto DONE;
+ case '"': /* opening quote */
+ r++;
+ u = v = 0;
+ do {
+ skip (r, ' ');
+ if (sscanf (r, "%f %n", &d, &j) > 0) {
+ s = r + j; /* jump behind number, eat also blanks, if any */
+ if (*(s - 1) == 'E' || *(s - 1) == 'e')
+ s--; /* e. g. 0.5ExtendFont: \%f = 0.5E */
+ if (str_prefix (s, "SlantFont")) {
+ d *= 1000.0; /* correct rounding also for neg. numbers */
+ fm->slant = (short int) (d > 0 ? d + 0.5 : d - 0.5);
+ r = s + strlen ("SlantFont");
+ } else if (str_prefix (s, "ExtendFont")) {
+ d *= 1000.0;
+ fm->extend = (short int) (d > 0 ? d + 0.5 : d - 0.5);
+ if (fm->extend == 1000)
+ fm->extend = 0;
+ r = s + strlen ("ExtendFont");
+ } else { /* unknown name */
+ for (r = s;
+ *r != ' ' && *r != '"' && *r != '\0';
+ r++); /* jump over name */
+ c = *r; /* remember char for temporary end of string */
+ *r = '\0';
+ mp_snprintf(warn_s,128,
+ "invalid entry for `%s': unknown name `%s' ignored",
+ fm->tfm_name, s);
+ mp_warn(mp,warn_s);
+ *r = c;
+ }
+ } else
+ for (; *r != ' ' && *r != '"' && *r != '\0'; r++);
+ }
+ while (*r == ' ');
+ if (*r == '"') /* closing quote */
+ r++;
+ else {
+ mp_snprintf(warn_s,128,
+ "invalid entry for `%s': closing quote missing",
+ fm->tfm_name);
+ mp_warn(mp,warn_s);
+ goto bad_line;
+ }
+ break;
+ case 'P': /* handle cases for subfonts like 'PidEid=3,1' */
+ if (sscanf (r, "PidEid=%i, %i %n", &a, &b, &c) >= 2) {
+ fm->pid = (short int)a;
+ fm->eid = (short int)b;
+ r += c;
+ break;
+ } /* fallthrough */
+ default: /* encoding or font file specification */
+ a = b = 0;
+ if (*r == '<') {
+ a = *r++;
+ if (*r == '<' || *r == '[')
+ b = *r++;
+ }
+ read_field (r, q, buf);
+ /* encoding, formats: '8r.enc' or '<8r.enc' or '<[8r.enc' */
+ if (strlen (buf) > 4 && mp_strcasecmp (strend (buf) - 4, ".enc") == 0) {
+ fm->encoding = mp_add_enc (mp, buf);
+ u = v = 0; /* u, v used if intervening blank: "<< foo" */
+ } else if (strlen (buf) > 0) { /* file name given */
+ /* font file, formats:
+ * subsetting: '<cmr10.pfa'
+ * no subsetting: '<<cmr10.pfa'
+ * no embedding: 'cmr10.pfa'
+ */
+ if (a == '<' || u == '<') {
+ set_included (fm);
+ if ((a == '<' && b == 0) || (a == 0 && v == 0))
+ set_subsetted (fm);
+ /* otherwise b == '<' (or '[') => no subsetting */
+ }
+ set_field (ff_name);
+ u = v = 0;
+ } else {
+ u = a;
+ v = b;
+ }
+ }
+ }
+ DONE:
+ if (fm->ps_name != NULL && check_basefont (fm->ps_name))
+ set_basefont (fm);
+ if (is_fontfile (fm)
+ && mp_strcasecmp (strend (fm_fontfile (fm)) - 4, ".ttf") == 0)
+ set_truetype (fm);
+ if (check_fm_entry (mp,fm, true) != 0)
+ goto bad_line;
+ /*
+ Until here the map line has been completely scanned without errors;
+ fm points to a valid, freshly filled-out |fm_entry| structure.
+ Now follows the actual work of registering/deleting.
+ */
+ if (avl_do_entry (mp, fm, mp->ps->mitem->mode) == 0) /* if success */
+ return;
+ bad_line:
+ delete_fm_entry (fm);
+}
+
+@
+@c static void fm_read_info (MP mp) {
+ char *n;
+ char s[256];
+ if (mp->ps->tfm_tree == NULL)
+ create_avl_trees (mp);
+ if (mp->ps->mitem->map_line == NULL) /* nothing to do */
+ return;
+ mp->ps->mitem->lineno = 1;
+ switch (mp->ps->mitem->type) {
+ case MAPFILE:
+ n = mp->ps->mitem->map_line;
+ mp->ps->fm_file = (mp->open_file)(mp, n, "r", mp_filetype_fontmap);
+ if (!mp->ps->fm_file) {
+ mp_snprintf(s,256,"cannot open font map file %s",n);
+ mp_warn(mp,s);
+ } else {
+ unsigned save_selector = mp->selector;
+ mp_normalize_selector(mp);
+ mp_print (mp, "{");
+ mp_print (mp, n);
+ while (!fm_eof ()) {
+ fm_scan_line (mp);
+ mp->ps->mitem->lineno++;
+ }
+ fm_close ();
+ mp_print (mp,"}");
+ mp->selector = save_selector;
+ mp->ps->fm_file = NULL;
+ }
+ mp_xfree(n);
+ break;
+ case MAPLINE:
+ fm_scan_line (mp);
+ break;
+ default:
+ assert (0);
+ }
+ mp->ps->mitem->map_line = NULL; /* done with this line */
+ return;
+}
+
+@ @c static void init_fm (fm_entry * fm, font_number f) {
+ if (fm->tfm_num == null_font ) {
+ fm->tfm_num = f;
+ fm->tfm_avail = TFM_FOUND;
+ }
+}
+
+@ @<Exported function ...@>=
+fm_entry * mp_fm_lookup (MP mp, font_number f);
+
+@ @c
+fm_entry * mp_fm_lookup (MP mp, font_number f) {
+ char *tfm;
+ fm_entry *fm;
+ fm_entry tmp;
+ int e;
+ if (mp->ps->tfm_tree == NULL)
+ fm_read_info (mp); /* only to read default map file */
+ tfm = mp->font_name[f];
+ assert (strcmp (tfm, nontfm));
+ /* Look up for full <tfmname>[+-]<expand> */
+ tmp.tfm_name = tfm;
+ fm = (fm_entry *) avl_find (&tmp, mp->ps->tfm_tree);
+ if (fm != NULL) {
+ init_fm (fm, f);
+ return (fm_entry *) fm;
+ }
+ tfm = mk_base_tfm (mp, mp->font_name[f], &e);
+ if (tfm == NULL) /* not an expanded font, nothing to do */
+ return NULL;
+
+ tmp.tfm_name = tfm;
+ fm = (fm_entry *) avl_find (&tmp, mp->ps->tfm_tree);
+ if (fm != NULL) { /* found an entry with the base tfm name, e.g. cmr10 */
+ return (fm_entry *) fm; /* font expansion uses the base font */
+ }
+ return NULL;
+}
+
+@ Early check whether a font file exists. Used e. g. for replacing fonts
+ of embedded PDF files: Without font file, the font within the embedded
+ PDF-file is used. Search tree |ff_tree| is used in 1st instance, as it
+ may be faster than the |kpse_find_file()|, and |kpse_find_file()| is called
+ only once per font file name + expansion parameter. This might help
+ keeping speed, if many PDF pages with same fonts are to be embedded.
+
+ The |ff_tree| contains only font files, which are actually needed,
+ so this tree typically is much smaller than the |tfm_tree| or |ps_tree|.
+
+@c
+static ff_entry *check_ff_exist (MP mp, fm_entry * fm) {
+ ff_entry *ff;
+ ff_entry tmp;
+ void **aa;
+
+ assert (fm->ff_name != NULL);
+ tmp.ff_name = fm->ff_name;
+ ff = (ff_entry *) avl_find (&tmp, mp->ps->ff_tree);
+ if (ff == NULL) { /* not yet in database */
+ ff = new_ff_entry (mp);
+ ff->ff_name = mp_xstrdup (mp,fm->ff_name);
+ ff->ff_path = mp_xstrdup (mp,fm->ff_name);
+ aa = avl_probe (mp->ps->ff_tree, ff);
+ assert (aa != NULL);
+ }
+ return ff;
+}
+
+@ Process map file given by its name or map line contents. Items not
+beginning with [+-=] flush default map file, if it has not yet been
+read. Leading blanks and blanks immediately following [+-=] are ignored.
+
+
+@c static void mp_process_map_item (MP mp, char *s, int type) {
+ char *p;
+ int mode;
+ if (*s == ' ')
+ s++; /* ignore leading blank */
+ switch (*s) {
+ case '+': /* +mapfile.map, +mapline */
+ mode = FM_DUPIGNORE; /* insert entry, if it is not duplicate */
+ s++;
+ break;
+ case '=': /* =mapfile.map, =mapline */
+ mode = FM_REPLACE; /* try to replace earlier entry */
+ s++;
+ break;
+ case '-': /* -mapfile.map, -mapline */
+ mode = FM_DELETE; /* try to delete entry */
+ s++;
+ break;
+ default:
+ mode = FM_DUPIGNORE; /* like +, but also: */
+ mp_xfree(mp->ps->mitem->map_line);
+ mp->ps->mitem->map_line = NULL; /* flush default map file name */
+ }
+ if (*s == ' ')
+ s++; /* ignore blank after [+-=] */
+ p = s; /* map item starts here */
+ switch (type) {
+ case MAPFILE: /* remove blank at end */
+ while (*p != '\0' && *p != ' ')
+ p++;
+ *p = '\0';
+ break;
+ case MAPLINE: /* blank at end allowed */
+ break;
+ default:
+ assert (0);
+ }
+ if (mp->ps->mitem->map_line != NULL) /* read default map file first */
+ fm_read_info (mp);
+ if (*s != '\0') { /* only if real item to process */
+ mp->ps->mitem->mode = mode;
+ mp->ps->mitem->type = type;
+ mp->ps->mitem->map_line = s;
+ fm_read_info (mp);
+ }
+}
+
+@ @<Exported function headers@>=
+void mp_map_file (MP mp, str_number t);
+void mp_map_line (MP mp, str_number t);
+void mp_init_map_file (MP mp, int is_troff);
+
+@ @c
+void mp_map_file (MP mp, str_number t) {
+ char *s = mp_xstrdup(mp,mp_str (mp,t));
+ mp_process_map_item (mp, s, MAPFILE);
+}
+void mp_map_line (MP mp, str_number t) {
+ char *s = mp_xstrdup(mp,mp_str (mp,t));
+ mp_process_map_item (mp, s, MAPLINE);
+}
+
+@
+@c void mp_init_map_file (MP mp, int is_troff) {
+ char *r;
+ mp->ps->mitem = mp_xmalloc (mp,1,sizeof(mapitem));
+ mp->ps->mitem->mode = FM_DUPIGNORE;
+ mp->ps->mitem->type = MAPFILE;
+ mp->ps->mitem->map_line = NULL;
+ r = (mp->find_file)(mp,"mpost.map", "r", mp_filetype_fontmap);
+ if (r != NULL) {
+ mp_xfree(r);
+ mp->ps->mitem->map_line = mp_xstrdup (mp,"mpost.map");
+ } else {
+ if (is_troff) {
+ mp->ps->mitem->map_line = mp_xstrdup (mp,"troff.map");
+ } else {
+ mp->ps->mitem->map_line = mp_xstrdup (mp,"pdftex.map");
+ }
+ }
+}
+
+@ @<Dealloc variables@>=
+if (mp->ps->mitem!=NULL) {
+ mp_xfree(mp->ps->mitem->map_line);
+ mp_xfree(mp->ps->mitem);
+}
+
+@ cleaning up...
+
+@c
+static void destroy_fm_entry_tfm (void *pa, void *pb) {
+ fm_entry *fm;
+ (void)pb;
+ fm = (fm_entry *) pa;
+ if (!has_pslink (fm))
+ delete_fm_entry (fm);
+ else
+ unset_tfmlink (fm);
+}
+static void destroy_fm_entry_ps (void *pa, void *pb) {
+ fm_entry *fm;
+ (void)pb;
+ fm = (fm_entry *) pa;
+ if (!has_tfmlink (fm))
+ delete_fm_entry (fm);
+ else
+ unset_pslink (fm);
+}
+static void destroy_ff_entry (void *pa, void *pb) {
+ ff_entry *ff;
+ (void)pb;
+ ff = (ff_entry *) pa;
+ delete_ff_entry (ff);
+}
+
+@ @<Declarations@>=
+static void fm_free (MP mp);
+
+@ @c
+static void fm_free (MP mp) {
+ if (mp->ps->tfm_tree != NULL)
+ avl_destroy (mp->ps->tfm_tree);
+ if (mp->ps->ps_tree != NULL)
+ avl_destroy (mp->ps->ps_tree);
+ if (mp->ps->ff_tree != NULL)
+ avl_destroy (mp->ps->ff_tree);
+}
+
+@ The file |ps_tab_file| gives a table of \TeX\ font names and corresponding
+PostScript names for fonts that do not have to be downloaded, i.e., fonts that
+can be used when |internal[prologues]>0|. Each line consists of a \TeX\ name,
+one or more spaces, a PostScript name, and possibly a space and some other junk.
+This routine reads the table, updates |font_ps_name| entries starting after
+|last_ps_fnum|, and sets |last_ps_fnum:=last_fnum|.
+
+@d ps_tab_name "psfonts.map" /* locates font name translation table */
+
+@<Exported function ...@>=
+void mp_read_psname_table (MP mp) ;
+
+@ @c
+void mp_read_psname_table (MP mp) {
+ font_number k;
+ if (mp->ps->mitem == NULL) {
+ mp->ps->mitem = mp_xmalloc (mp,1,sizeof(mapitem));
+ mp->ps->mitem->mode = FM_DUPIGNORE;
+ mp->ps->mitem->type = MAPFILE;
+ mp->ps->mitem->map_line = NULL;
+ }
+ mp->ps->mitem->map_line = mp_xstrdup (mp,ps_tab_name);
+ fm_read_info (mp);
+ for (k=mp->last_ps_fnum+1;k<=mp->last_fnum;k++) {
+ if (mp_has_fm_entry(mp, k, NULL)) {
+ mp->font_ps_name[k] = mp_fm_font_name(mp,k);
+ }
+ }
+ mp->last_ps_fnum=mp->last_fnum;
+}
+
+
+@ The traditional function is a lot shorter now.
+
+
+
+@* \[44c] Helper functions for Type1 fonts.
+
+@<Types...@>=
+typedef char char_entry;
+typedef unsigned char Byte;
+typedef Byte Bytef;
+
+@ @<Glob...@>=
+char_entry *char_ptr, *char_array;
+size_t char_limit;
+char *job_id_string;
+
+@ @<Set initial...@>=
+mp->ps->char_array = NULL;
+mp->ps->job_id_string = NULL;
+
+@
+@d SMALL_ARRAY_SIZE 256
+@d Z_NULL 0
+
+@c
+void mp_set_job_id (MP mp) {
+ char *name_string, *format_string, *s;
+ size_t slen;
+ if (mp->ps->job_id_string != NULL)
+ return;
+ if ( mp->job_name==NULL )
+ mp->job_name = mp_xstrdup(mp,"mpout");
+ name_string = mp_xstrdup (mp,mp->job_name);
+ format_string = mp_xstrdup (mp,mp->mem_ident);
+ slen = SMALL_BUF_SIZE +
+ strlen (name_string) +
+ strlen (format_string);
+ s = mp_xmalloc (mp,slen, sizeof (char));
+ @= /*@@-bufferoverflowhigh@@*/ @>
+ sprintf (s,"%.4u/%.2u/%.2u %.2u:%.2u %s %s",
+ ((unsigned)mp->internal[mp_year]>>16),
+ ((unsigned)mp->internal[mp_month]>>16),
+ ((unsigned)mp->internal[mp_day]>>16),
+ ((unsigned)mp->internal[mp_time]>>16) / 60,
+ ((unsigned)mp->internal[mp_time]>>16) % 60,
+ name_string, format_string);
+ @= /*@@=bufferoverflowhigh@@*/ @>
+ mp->ps->job_id_string = mp_xstrdup (mp,s);
+ mp_xfree (s);
+ mp_xfree (name_string);
+ mp_xfree (format_string);
+}
+static void fnstr_append (MP mp, const char *s) {
+ size_t l = strlen (s) + 1;
+ alloc_array (char, l, SMALL_ARRAY_SIZE);
+ strcat (mp->ps->char_ptr, s);
+ mp->ps->char_ptr = strend (mp->ps->char_ptr);
+}
+
+@ @<Exported function headers@>=
+void mp_set_job_id (MP mp) ;
+
+@ @<Dealloc variables@>=
+mp_xfree(mp->ps->job_id_string);
+
+@ this is not really a true crc32, but it should be just enough to keep
+ subsets prefixes somewhat disjunct
+
+@c
+static unsigned long crc32 (unsigned long oldcrc, const Byte *buf, size_t len) {
+ unsigned long ret = 0;
+ size_t i;
+ if (oldcrc==0)
+ ret = (unsigned long)((23<<24)+(45<<16)+(67<<8)+89);
+ else
+ for (i=0;i<len;i++)
+ ret = (ret<<2)+buf[i];
+ return ret;
+}
+static boolean mp_char_marked (MP mp,font_number f, eight_bits c) {
+ integer b; /* |char_base[f]| */
+ b=mp->char_base[f];
+ if ( (c>=mp->font_bc[f])&&(c<=mp->font_ec[f])&&(mp->font_info[b+c].qqqq.b3!=0) )
+ return true;
+ else
+ return false;
+}
+
+static void make_subset_tag (MP mp, fm_entry * fm_cur, char **glyph_names, font_number tex_font)
+{
+ char tag[7];
+ unsigned long crc;
+ int i;
+ size_t l ;
+ if (mp->ps->job_id_string ==NULL)
+ mp_fatal_error(mp, "no job id!");
+ l = strlen (mp->ps->job_id_string) + 1;
+
+ alloc_array (char, l, SMALL_ARRAY_SIZE);
+ strcpy (mp->ps->char_array, mp->ps->job_id_string);
+ mp->ps->char_ptr = strend (mp->ps->char_array);
+ if (fm_cur->tfm_name != NULL) {
+ fnstr_append (mp," TFM name: ");
+ fnstr_append (mp,fm_cur->tfm_name);
+ }
+ fnstr_append (mp," PS name: ");
+ if (fm_cur->ps_name != NULL)
+ fnstr_append (mp,fm_cur->ps_name);
+ fnstr_append (mp," Encoding: ");
+ if (fm_cur->encoding != NULL && (fm_cur->encoding)->file_name != NULL)
+ fnstr_append (mp,(fm_cur->encoding)->file_name);
+ else
+ fnstr_append (mp,"built-in");
+ fnstr_append (mp," CharSet: ");
+ for (i = 0; i < 256; i++)
+ if (mp_char_marked (mp,tex_font, (eight_bits)i) && glyph_names[i] != notdef) {
+ if (glyph_names[i]!=NULL) {
+ fnstr_append (mp,"/");
+ fnstr_append (mp,glyph_names[i]);
+ }
+ }
+ if (fm_cur->charset != NULL) {
+ fnstr_append (mp," Extra CharSet: ");
+ fnstr_append (mp, fm_cur->charset);
+ }
+ crc = crc32 (0L, Z_NULL, 0);
+ crc = crc32 (crc, (Bytef *) mp->ps->char_array, strlen (mp->ps->char_array));
+ /* we need to fit a 32-bit number into a string of 6 uppercase chars long;
+ * there are 26 uppercase chars ==> each char represents a number in range
+ * |0..25|. The maximal number that can be represented by the tag is
+ * $26^6 - 1$, which is a number between $2^28$ and $2^29$. Thus the bits |29..31|
+ * of the CRC must be dropped out.
+ */
+ for (i = 0; i < 6; i++) {
+ tag[i] = 'A' + crc % 26;
+ crc /= 26;
+ }
+ tag[6] = 0;
+ fm_cur->subset_tag = mp_xstrdup (mp,tag);
+}
+
+
+
+@
+@d external_enc() (fm_cur->encoding)->glyph_names
+@d is_used_char(c) mp_char_marked (mp, tex_font, (eight_bits)c)
+@d end_last_eexec_line()
+ mp->ps->hexline_length = HEXLINE_WIDTH;
+ end_hexline(mp);
+ mp->ps->t1_eexec_encrypt = false
+@d t1_log(s) mp_print(mp,(char *)s)
+@d t1_putchar(c) wps_chr(c)
+@d embed_all_glyphs(tex_font) false
+@d t1_char(c) c
+@d extra_charset() mp->ps->dvips_extra_charset
+@d update_subset_tag()
+@d fixedcontent true
+
+@<Glob...@>=
+#define PRINTF_BUF_SIZE 1024
+char *dvips_extra_charset;
+char *cur_enc_name;
+unsigned char *grid;
+char *ext_glyph_names[256];
+char print_buf[PRINTF_BUF_SIZE];
+int t1_byte_waiting;
+
+@ @<Set initial ...@>=
+mp->ps->dvips_extra_charset=NULL;
+mp->ps->t1_byte_waiting=0;
+
+@
+@d t1_ungetchar(A) mp->ps->t1_byte_waiting=(int)(A)
+@d t1_eof() (mp->eof_file)(mp,mp->ps->t1_file)
+@d t1_close() (mp->close_file)(mp,mp->ps->t1_file)
+@d valid_code(c) (c >= 0 && c < 256)
+
+@c
+static int t1_getchar (MP mp) {
+ size_t len = 1;
+ unsigned char abyte=0;
+ void *byte_ptr = &abyte;
+ if (mp->ps->t1_byte_waiting) {
+ abyte = mp->ps->t1_byte_waiting;
+ mp->ps->t1_byte_waiting = 0;
+ } else {
+ (mp->read_binary_file)(mp,mp->ps->t1_file,&byte_ptr,&len);
+ }
+ return (int)abyte;
+}
+
+@ @<Static variables in the outer block@>=
+static const char *standard_glyph_names[256] =
+ { notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef,
+ notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef,
+ notdef, notdef, notdef, notdef, notdef, notdef,
+ notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef,
+ "space", "exclam", "quotedbl", "numbersign",
+ "dollar", "percent", "ampersand", "quoteright", "parenleft",
+ "parenright", "asterisk", "plus", "comma", "hyphen", "period",
+ "slash", "zero", "one", "two", "three", "four", "five", "six", "seven",
+ "eight", "nine", "colon", "semicolon", "less",
+ "equal", "greater", "question", "at", "A", "B", "C", "D", "E", "F",
+ "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q",
+ "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "bracketleft",
+ "backslash", "bracketright", "asciicircum", "underscore",
+ "quoteleft", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k",
+ "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v",
+ "w", "x", "y", "z", "braceleft", "bar", "braceright", "asciitilde",
+ notdef, notdef, notdef, notdef, notdef, notdef, notdef,
+ notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef,
+ notdef, notdef, notdef, notdef, notdef, notdef,
+ notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef,
+ notdef, notdef, notdef, "exclamdown", "cent",
+ "sterling", "fraction", "yen", "florin", "section", "currency",
+ "quotesingle", "quotedblleft", "guillemotleft",
+ "guilsinglleft", "guilsinglright", "fi", "fl", notdef, "endash",
+ "dagger", "daggerdbl", "periodcentered", notdef,
+ "paragraph", "bullet", "quotesinglbase", "quotedblbase",
+ "quotedblright", "guillemotright", "ellipsis", "perthousand",
+ notdef, "questiondown", notdef, "grave", "acute", "circumflex",
+ "tilde", "macron", "breve", "dotaccent", "dieresis", notdef,
+ "ring", "cedilla", notdef, "hungarumlaut", "ogonek", "caron", "emdash",
+ notdef, notdef, notdef, notdef, notdef, notdef,
+ notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef, notdef,
+ notdef, "AE", notdef, "ordfeminine", notdef, notdef,
+ notdef, notdef, "Lslash", "Oslash", "OE", "ordmasculine", notdef,
+ notdef, notdef, notdef, notdef, "ae", notdef, notdef,
+ notdef, "dotlessi", notdef, notdef, "lslash", "oslash", "oe",
+ "germandbls", notdef, notdef, notdef, notdef };
+static const char charstringname[] = "/CharStrings";
+
+@ @<Glob...@>=
+char **t1_glyph_names;
+char *t1_builtin_glyph_names[256];
+char charsetstr[0x4000];
+boolean read_encoding_only;
+int t1_encoding;
+
+@ @c
+#define T1_BUF_SIZE 0x10
+
+#define CS_HSTEM 1
+#define CS_VSTEM 3
+#define CS_VMOVETO 4
+#define CS_RLINETO 5
+#define CS_HLINETO 6
+#define CS_VLINETO 7
+#define CS_RRCURVETO 8
+#define CS_CLOSEPATH 9
+#define CS_CALLSUBR 10
+#define CS_RETURN 11
+#define CS_ESCAPE 12
+#define CS_HSBW 13
+#define CS_ENDCHAR 14
+#define CS_RMOVETO 21
+#define CS_HMOVETO 22
+#define CS_VHCURVETO 30
+#define CS_HVCURVETO 31
+#define CS_1BYTE_MAX (CS_HVCURVETO + 1)
+
+#define CS_DOTSECTION CS_1BYTE_MAX + 0
+#define CS_VSTEM3 CS_1BYTE_MAX + 1
+#define CS_HSTEM3 CS_1BYTE_MAX + 2
+#define CS_SEAC CS_1BYTE_MAX + 6
+#define CS_SBW CS_1BYTE_MAX + 7
+#define CS_DIV CS_1BYTE_MAX + 12
+#define CS_CALLOTHERSUBR CS_1BYTE_MAX + 16
+#define CS_POP CS_1BYTE_MAX + 17
+#define CS_SETCURRENTPOINT CS_1BYTE_MAX + 33
+#define CS_2BYTE_MAX (CS_SETCURRENTPOINT + 1)
+#define CS_MAX CS_2BYTE_MAX
+
+@ @<Types...@>=
+typedef unsigned char byte;
+typedef struct {
+ byte nargs; /* number of arguments */
+ boolean bottom; /* take arguments from bottom of stack? */
+ boolean clear; /* clear stack? */
+ boolean valid;
+} cc_entry; /* CharString Command */
+typedef struct {
+ char *glyph_name; /* glyph name (or notdef for Subrs entry) */
+ byte *data;
+ unsigned short len; /* length of the whole string */
+ unsigned short cslen; /* length of the encoded part of the string */
+ boolean is_used;
+ boolean valid;
+} cs_entry;
+
+@
+@d t1_c1 52845
+@d t1_c2 22719
+
+@<Glob...@>=
+unsigned short t1_dr, t1_er;
+unsigned short t1_cslen;
+short t1_lenIV;
+
+@ @<Types...@>=
+typedef char t1_line_entry;
+typedef char t1_buf_entry;
+
+@ @<Glob...@>=
+t1_line_entry *t1_line_ptr, *t1_line_array;
+size_t t1_line_limit;
+t1_buf_entry *t1_buf_ptr, *t1_buf_array;
+size_t t1_buf_limit;
+int cs_start;
+cs_entry *cs_tab, *cs_ptr, *cs_notdef;
+char *cs_dict_start, *cs_dict_end;
+int cs_count, cs_size, cs_size_pos;
+cs_entry *subr_tab;
+char *subr_array_start, *subr_array_end;
+int subr_max, subr_size, subr_size_pos;
+
+@ @<Set initial...@>=
+mp->ps->t1_line_array = NULL;
+mp->ps->t1_buf_array = NULL;
+
+@
+ This list contains the begin/end tokens commonly used in the
+ /Subrs array of a Type 1 font.
+
+@<Static variables in the outer block@>=
+static const char *cs_token_pairs_list[][2] = {
+ {" RD", "NP"},
+ {" -|", "|"},
+ {" RD", "noaccess put"},
+ {" -|", "noaccess put"},
+ {NULL, NULL}
+};
+
+@ @<Glob...@>=
+const char **cs_token_pair;
+boolean t1_pfa, t1_cs, t1_scan, t1_eexec_encrypt, t1_synthetic;
+int t1_in_eexec; /* 0 before eexec-encrypted, 1 during, 2 after */
+int t1_block_length;
+int last_hexbyte;
+void *t1_file;
+int hexline_length;
+
+@
+@d HEXLINE_WIDTH 64
+
+@<Set initial ...@>=
+mp->ps->hexline_length = 0;
+
+@
+@d t1_prefix(s) str_prefix(mp->ps->t1_line_array, s)
+@d t1_buf_prefix(s) str_prefix(mp->ps->t1_buf_array, s)
+@d t1_suffix(s) str_suffix(mp->ps->t1_line_array, mp->ps->t1_line_ptr, s)
+@d t1_buf_suffix(s) str_suffix(mp->ps->t1_buf_array, mp->ps->t1_buf_ptr, s)
+@d t1_charstrings() strstr(mp->ps->t1_line_array, charstringname)
+@d t1_subrs() t1_prefix("/Subrs")
+@d t1_end_eexec() t1_suffix("mark currentfile closefile")
+@d t1_cleartomark() t1_prefix("cleartomark")
+
+@c
+static void end_hexline (MP mp) {
+ if (mp->ps->hexline_length >= HEXLINE_WIDTH) {
+ wps_cr;
+ mp->ps->hexline_length = 0;
+ }
+}
+static void t1_check_pfa (MP mp) {
+ const int c = t1_getchar (mp);
+ mp->ps->t1_pfa = (c != 128) ? true : false;
+ t1_ungetchar (c);
+}
+static int t1_getbyte (MP mp)
+{
+ int c = t1_getchar (mp);
+ if (mp->ps->t1_pfa)
+ return c;
+ if (mp->ps->t1_block_length == 0) {
+ if (c != 128)
+ mp_fatal_error (mp, "invalid marker");
+ c = t1_getchar (mp);
+ if (c == 3) {
+ while (!t1_eof ())
+ (void)t1_getchar (mp);
+ return EOF;
+ }
+ mp->ps->t1_block_length = t1_getchar (mp) & 0xff;
+ mp->ps->t1_block_length |= (unsigned)(t1_getchar (mp) & 0xff) << 8;
+ mp->ps->t1_block_length |= (unsigned)(t1_getchar (mp) & 0xff) << 16;
+ mp->ps->t1_block_length |= (unsigned)(t1_getchar (mp) & 0xff) << 24;
+ c = t1_getchar (mp);
+ }
+ mp->ps->t1_block_length--;
+ return c;
+}
+static int hexval (int c) {
+ if (c >= 'A' && c <= 'F')
+ return c - 'A' + 10;
+ else if (c >= 'a' && c <= 'f')
+ return c - 'a' + 10;
+ else if (c >= '0' && c <= '9')
+ return c - '0';
+ else
+ return -1;
+}
+static byte edecrypt (MP mp, byte cipher) {
+ byte plain;
+ if (mp->ps->t1_pfa) {
+ while (cipher == 10 || cipher == 13)
+ cipher = (byte)t1_getbyte (mp);
+ mp->ps->last_hexbyte = cipher = (byte)(((byte)hexval (cipher) << 4) +
+ hexval (t1_getbyte (mp)));
+ }
+ plain = (cipher ^ (mp->ps->t1_dr >> 8));
+ mp->ps->t1_dr = (cipher + mp->ps->t1_dr) * t1_c1 + t1_c2;
+ return plain;
+}
+static byte cdecrypt (byte cipher, unsigned short *cr)
+{
+ const byte plain = (cipher ^ (*cr >> 8));
+ *cr = (cipher + *cr) * t1_c1 + t1_c2;
+ return plain;
+}
+static byte eencrypt (MP mp, byte plain)
+{
+ const byte cipher = (plain ^ (mp->ps->t1_er >> 8));
+ mp->ps->t1_er = (cipher + mp->ps->t1_er) * t1_c1 + t1_c2;
+ return cipher;
+}
+
+static byte cencrypt (byte plain, unsigned short *cr)
+{
+ const byte cipher = (plain ^ (*cr >> 8));
+ *cr = (cipher + *cr) * t1_c1 + t1_c2;
+ return cipher;
+}
+
+static char *eol (char *s) {
+ char *p = strend (s);
+ if (p!=NULL && p - s > 1 && p[-1] != 10) {
+ *p++ = 10;
+ *p = 0;
+ }
+ return p;
+}
+static float t1_scan_num (MP mp, char *p, char **r)
+{
+ float f;
+ char s[128];
+ skip (p, ' ');
+ if (sscanf (p, "%g", &f) != 1) {
+ remove_eol (p, mp->ps->t1_line_array);
+ mp_snprintf(s,128, "a number expected: `%s'", mp->ps->t1_line_array);
+ mp_fatal_error(mp,s);
+ }
+ if (r != NULL) {
+ for (; mp_isdigit (*p) || *p == '.' ||
+ *p == 'e' || *p == 'E' || *p == '+' || *p == '-'; p++);
+ *r = p;
+ }
+ return f;
+}
+
+static boolean str_suffix (const char *begin_buf, const char *end_buf,
+ const char *s)
+{
+ const char *s1 = end_buf - 1, *s2 = strend (s) - 1;
+ if (*s1 == 10)
+ s1--;
+ while (s1 >= begin_buf && s2 >= s) {
+ if (*s1-- != *s2--)
+ return false;
+ }
+ return s2 < s;
+}
+
+@
+
+@d alloc_array(T, n, s) do {
+ if (mp->ps->T##_array == NULL) {
+ mp->ps->T##_limit = (s);
+ if ((size_t)(n) > mp->ps->T##_limit)
+ mp->ps->T##_limit = (size_t)(n);
+ mp->ps->T##_array = mp_xmalloc (mp,mp->ps->T##_limit,sizeof(T##_entry));
+ mp->ps->T##_ptr = mp->ps->T##_array;
+ }
+ else if ((size_t)(mp->ps->T##_ptr - mp->ps->T##_array + (n)) > mp->ps->T##_limit) {
+ size_t last_ptr_index;
+ last_ptr_index = (size_t)(mp->ps->T##_ptr - mp->ps->T##_array);
+ mp->ps->T##_limit *= 2;
+ if ((size_t)(mp->ps->T##_ptr - mp->ps->T##_array + (n)) > mp->ps->T##_limit)
+ mp->ps->T##_limit = (size_t)(mp->ps->T##_ptr - mp->ps->T##_array + (n));
+ mp->ps->T##_array = mp_xrealloc(mp,mp->ps->T##_array,mp->ps->T##_limit, sizeof(T##_entry));
+ mp->ps->T##_ptr = mp->ps->T##_array + last_ptr_index;
+ }
+} while (0)
+
+@d out_eexec_char(A) t1_outhex(mp,(A))
+
+@c
+static void t1_outhex (MP mp, byte b)
+{
+ static const char *hexdigits = "0123456789ABCDEF";
+ t1_putchar (hexdigits[b / 16]);
+ t1_putchar (hexdigits[b % 16]);
+ mp->ps->hexline_length += 2;
+ end_hexline (mp);
+}
+static void t1_getline (MP mp) {
+ int c, l, eexec_scan;
+ char *p;
+ static const char eexec_str[] = "currentfile eexec";
+ static int eexec_len = 17; /* |strlen(eexec_str)| */
+ RESTART:
+ if (t1_eof ())
+ mp_fatal_error (mp,"unexpected end of file");
+ mp->ps->t1_line_ptr = mp->ps->t1_line_array;
+ alloc_array (t1_line, 1, T1_BUF_SIZE);
+ mp->ps->t1_cslen = 0;
+ eexec_scan = 0;
+ c = t1_getbyte (mp);
+ if (c == EOF)
+ goto EXIT;
+ while (!t1_eof ()) {
+ if (mp->ps->t1_in_eexec == 1)
+ c = edecrypt (mp,(byte)c);
+ alloc_array (t1_line, 1, T1_BUF_SIZE);
+ append_char_to_buf (c, mp->ps->t1_line_ptr, mp->ps->t1_line_array, mp->ps->t1_line_limit);
+ if (mp->ps->t1_in_eexec == 0 && eexec_scan >= 0 && eexec_scan < eexec_len) {
+ if (mp->ps->t1_line_array[eexec_scan] == eexec_str[eexec_scan])
+ eexec_scan++;
+ else
+ eexec_scan = -1;
+ }
+ if (c == 10 || (mp->ps->t1_pfa && eexec_scan == eexec_len && c == 32))
+ break;
+ if (mp->ps->t1_cs && mp->ps->t1_cslen == 0 &&
+ (mp->ps->t1_line_ptr - mp->ps->t1_line_array > 4) &&
+ (t1_suffix (" RD ") || t1_suffix (" -| "))) {
+ p = mp->ps->t1_line_ptr - 5;
+ while (*p != ' ')
+ p--;
+ l = (int)t1_scan_num (mp, p + 1, 0);
+ mp->ps->t1_cslen = (unsigned short)l;
+ mp->ps->cs_start = mp->ps->t1_line_ptr - mp->ps->t1_line_array;
+ /* |mp->ps->cs_start| is an index now */
+ alloc_array (t1_line, l, T1_BUF_SIZE);
+ while (l-- > 0) {
+ *mp->ps->t1_line_ptr = (t1_line_entry)edecrypt (mp,(byte)t1_getbyte (mp));
+ mp->ps->t1_line_ptr++;
+ }
+ }
+ c = t1_getbyte (mp);
+ }
+ alloc_array (t1_line, 2, T1_BUF_SIZE); /* |append_eol| can append 2 chars */
+ append_eol (mp->ps->t1_line_ptr, mp->ps->t1_line_array, mp->ps->t1_line_limit);
+ if (mp->ps->t1_line_ptr - mp->ps->t1_line_array < 2)
+ goto RESTART;
+ if (eexec_scan == eexec_len)
+ mp->ps->t1_in_eexec = 1;
+ EXIT:
+ /* ensure that |mp->ps->t1_buf_array| has as much room as |t1_line_array| */
+ mp->ps->t1_buf_ptr = mp->ps->t1_buf_array;
+ alloc_array (t1_buf, mp->ps->t1_line_limit, mp->ps->t1_line_limit);
+}
+
+static void t1_putline (MP mp)
+{
+ char *p = mp->ps->t1_line_array;
+ if (mp->ps->t1_line_ptr - mp->ps->t1_line_array <= 1)
+ return;
+ if (mp->ps->t1_eexec_encrypt) {
+ while (p < mp->ps->t1_line_ptr)
+ out_eexec_char (eencrypt (mp,(byte)*p++));
+ } else {
+ while (p < mp->ps->t1_line_ptr)
+ t1_putchar (*p++);
+ }
+}
+
+static void t1_puts (MP mp, const char *s)
+{
+ if (s != mp->ps->t1_line_array)
+ strcpy (mp->ps->t1_line_array, s);
+ mp->ps->t1_line_ptr = strend (mp->ps->t1_line_array);
+ t1_putline (mp);
+}
+
+static void t1_init_params (MP mp, const char *open_name_prefix,
+ char *cur_file_name) {
+ if ((open_name_prefix != NULL) && strlen(open_name_prefix)) {
+ t1_log (open_name_prefix);
+ t1_log (cur_file_name);
+ }
+ mp->ps->t1_lenIV = 4;
+ mp->ps->t1_dr = 55665;
+ mp->ps->t1_er = 55665;
+ mp->ps->t1_in_eexec = 0;
+ mp->ps->t1_cs = false;
+ mp->ps->t1_scan = true;
+ mp->ps->t1_synthetic = false;
+ mp->ps->t1_eexec_encrypt = false;
+ mp->ps->t1_block_length = 0;
+ t1_check_pfa (mp);
+}
+static void t1_close_font_file (MP mp, const char *close_name_suffix) {
+ if ((close_name_suffix != NULL) && strlen(close_name_suffix)) {
+ t1_log (close_name_suffix);
+ }
+ t1_close ();
+}
+
+static void t1_check_block_len (MP mp, boolean decrypt) {
+ int l, c;
+ char s[128];
+ if (mp->ps->t1_block_length == 0)
+ return;
+ c = t1_getbyte (mp);
+ if (decrypt)
+ c = edecrypt (mp,(byte)c);
+ l = mp->ps->t1_block_length;
+ if (!(l == 0 && (c == 10 || c == 13))) {
+ mp_snprintf(s,128,"%i bytes more than expected were ignored", l+ 1);
+ mp_warn(mp,s);
+ while (l-- > 0)
+ (void)t1_getbyte (mp);
+ }
+}
+static void t1_start_eexec (MP mp, fm_entry *fm_cur) {
+ int i;
+ if (!mp->ps->t1_pfa)
+ t1_check_block_len (mp, false);
+ for (mp->ps->t1_line_ptr = mp->ps->t1_line_array, i = 0; i < 4; i++) {
+ (void)edecrypt (mp, (byte)t1_getbyte (mp));
+ *mp->ps->t1_line_ptr++ = 0;
+ }
+ mp->ps->t1_eexec_encrypt = true;
+ if (!mp->ps->read_encoding_only)
+ if (is_included (fm_cur))
+ t1_putline (mp); /* to put the first four bytes */
+}
+static void t1_stop_eexec (MP mp) {
+ int c;
+ end_last_eexec_line ();
+ if (!mp->ps->t1_pfa)
+ t1_check_block_len (mp,true);
+ else {
+ c = edecrypt (mp, (byte)t1_getbyte (mp));
+ if (!(c == 10 || c == 13)) {
+ if (mp->ps->last_hexbyte == 0)
+ t1_puts (mp,"00");
+ else
+ mp_warn (mp,"unexpected data after eexec");
+ }
+ }
+ mp->ps->t1_cs = false;
+ mp->ps->t1_in_eexec = 2;
+}
+static void t1_modify_fm (MP mp) {
+ mp->ps->t1_line_ptr = eol (mp->ps->t1_line_array);
+}
+
+static void t1_modify_italic (MP mp) {
+ mp->ps->t1_line_ptr = eol (mp->ps->t1_line_array);
+}
+
+@ @<Types...@>=
+typedef struct {
+ const char *pdfname;
+ const char *t1name;
+ float value;
+ boolean valid;
+} key_entry;
+
+@
+@d FONT_KEYS_NUM 11
+
+@<Declarations@>=
+static key_entry font_keys[FONT_KEYS_NUM] = {
+ {"Ascent", "Ascender", 0, false},
+ {"CapHeight", "CapHeight", 0, false},
+ {"Descent", "Descender", 0, false},
+ {"FontName", "FontName", 0, false},
+ {"ItalicAngle", "ItalicAngle", 0, false},
+ {"StemV", "StdVW", 0, false},
+ {"XHeight", "XHeight", 0, false},
+ {"FontBBox", "FontBBox", 0, false},
+ {"", "", 0, false},
+ {"", "", 0, false},
+ {"", "", 0, false}
+};
+
+
+@
+@d ASCENT_CODE 0
+@d CAPHEIGHT_CODE 1
+@d DESCENT_CODE 2
+@d FONTNAME_CODE 3
+@d ITALIC_ANGLE_CODE 4
+@d STEMV_CODE 5
+@d XHEIGHT_CODE 6
+@d FONTBBOX1_CODE 7
+@d FONTBBOX2_CODE 8
+@d FONTBBOX3_CODE 9
+@d FONTBBOX4_CODE 10
+@d MAX_KEY_CODE (FONTBBOX1_CODE + 1)
+
+@c
+static void t1_scan_keys (MP mp, font_number tex_font,fm_entry *fm_cur) {
+ int i, k;
+ char *p, *r;
+ key_entry *key;
+ if (fm_extend (fm_cur) != 0 || fm_slant (fm_cur) != 0) {
+ if (t1_prefix ("/FontMatrix")) {
+ t1_modify_fm (mp);
+ return;
+ }
+ if (t1_prefix ("/ItalicAngle")) {
+ t1_modify_italic (mp);
+ return;
+ }
+ }
+ if (t1_prefix ("/FontType")) {
+ p = mp->ps->t1_line_array + strlen ("FontType") + 1;
+ if ((i = (int)t1_scan_num (mp,p, 0)) != 1) {
+ char s[128];
+ mp_snprintf(s,125,"Type%d fonts unsupported by metapost", i);
+ mp_fatal_error(mp,s);
+ }
+ return;
+ }
+ for (key = font_keys; key - font_keys < MAX_KEY_CODE; key++)
+ if (str_prefix (mp->ps->t1_line_array + 1, key->t1name))
+ break;
+ if (key - font_keys == MAX_KEY_CODE)
+ return;
+ key->valid = true;
+ p = mp->ps->t1_line_array + strlen (key->t1name) + 1;
+ skip (p, ' ');
+ if ((k = key - font_keys) == FONTNAME_CODE) {
+ if (*p != '/') {
+ char s[128];
+ remove_eol (p, mp->ps->t1_line_array);
+ mp_snprintf(s,128,"a name expected: `%s'", mp->ps->t1_line_array);
+ mp_fatal_error(mp,s);
+ }
+ r = ++p; /* skip the slash */
+ if (is_included (fm_cur)) {
+ /* save the fontname */
+ strncpy (mp->ps->fontname_buf, p, FONTNAME_BUF_SIZE);
+ for (i=0; mp->ps->fontname_buf[i] != 10; i++);
+ mp->ps->fontname_buf[i]=0;
+
+ if(is_subsetted (fm_cur)) {
+ if (fm_cur->encoding!=NULL && fm_cur->encoding->glyph_names!=NULL)
+ make_subset_tag (mp,fm_cur, fm_cur->encoding->glyph_names, tex_font);
+ else
+ make_subset_tag (mp,fm_cur, mp->ps->t1_builtin_glyph_names, tex_font);
+
+ alloc_array (t1_line, (r-mp->ps->t1_line_array+6+1+strlen(mp->ps->fontname_buf)+1),
+ T1_BUF_SIZE);
+ strncpy (r, fm_cur->subset_tag , 6);
+ *(r+6) = '-';
+ strncpy (r+7, mp->ps->fontname_buf, strlen(mp->ps->fontname_buf)+1);
+ mp->ps->t1_line_ptr = eol (r);
+ } else {
+ /* |for (q = p; *q != ' ' && *q != 10; *q++);|*/
+ /*|*q = 0;|*/
+ mp->ps->t1_line_ptr = eol (r);
+ }
+ }
+ return;
+ }
+ if ((k == STEMV_CODE || k == FONTBBOX1_CODE)
+ && (*p == '[' || *p == '{'))
+ p++;
+ if (k == FONTBBOX1_CODE) {
+ for (i = 0; i < 4; i++) {
+ key[i].value = t1_scan_num (mp, p, &r);
+ p = r;
+ }
+ return;
+ }
+ key->value = t1_scan_num (mp, p, 0);
+}
+static void t1_scan_param (MP mp, font_number tex_font,fm_entry *fm_cur)
+{
+ static const char *lenIV = "/lenIV";
+ if (!mp->ps->t1_scan || *mp->ps->t1_line_array != '/')
+ return;
+ if (t1_prefix (lenIV)) {
+ mp->ps->t1_lenIV = (short int)t1_scan_num (mp,mp->ps->t1_line_array + strlen (lenIV), 0);
+ return;
+ }
+ t1_scan_keys (mp, tex_font,fm_cur);
+}
+static void copy_glyph_names (MP mp, char **glyph_names, int a, int b) {
+ if (glyph_names[b] != notdef) {
+ mp_xfree (glyph_names[b]);
+ glyph_names[b] = (char *) notdef;
+ }
+ if (glyph_names[a] != notdef) {
+ glyph_names[b] = mp_xstrdup (mp,glyph_names[a]);
+ }
+}
+static void t1_builtin_enc (MP mp) {
+ int i, a, b, c, counter = 0;
+ char *r, *p;
+ /*
+ * At this moment "/Encoding" is the prefix of |mp->ps->t1_line_array|
+ */
+ if (t1_suffix ("def")) { /* predefined encoding */
+ (void)sscanf (mp->ps->t1_line_array + strlen ("/Encoding"), "%256s", mp->ps->t1_buf_array);
+ if (strcmp (mp->ps->t1_buf_array, "StandardEncoding") == 0) {
+ for (i = 0; i < 256; i++)
+ if (standard_glyph_names[i] == notdef)
+ mp->ps->t1_builtin_glyph_names[i] = (char *) notdef;
+ else
+ mp->ps->t1_builtin_glyph_names[i] =
+ mp_xstrdup (mp,standard_glyph_names[i]);
+ mp->ps->t1_encoding = ENC_STANDARD;
+ } else {
+ char s[128];
+ mp_snprintf(s,128, "cannot subset font (unknown predefined encoding `%s')",
+ mp->ps->t1_buf_array);
+ mp_fatal_error(mp,s);
+ }
+ return;
+ } else
+ mp->ps->t1_encoding = ENC_BUILTIN;
+ /*
+ * At this moment "/Encoding" is the prefix of |mp->ps->t1_line_array|, and the encoding is
+ * not a predefined encoding
+ *
+ * We have two possible forms of Encoding vector. The first case is
+ *
+ * /Encoding [/a /b /c...] readonly def
+ *
+ * and the second case can look like
+ *
+ * /Encoding 256 array 0 1 255 {1 index exch /.notdef put} for
+ * dup 0 /x put
+ * dup 1 /y put
+ * ...
+ * readonly def
+ */
+ for (i = 0; i < 256; i++)
+ mp->ps->t1_builtin_glyph_names[i] = (char *) notdef;
+ if (t1_prefix ("/Encoding [") || t1_prefix ("/Encoding[")) { /* the first case */
+ r = strchr (mp->ps->t1_line_array, '[') + 1;
+ skip (r, ' ');
+ for (;;) {
+ while (*r == '/') {
+ for (p = mp->ps->t1_buf_array, r++;
+ *r != 32 && *r != 10 && *r != ']' && *r != '/';
+ *p++ = *r++);
+ *p = 0;
+ skip (r, ' ');
+ if (counter > 255) {
+ mp_fatal_error
+ (mp, "encoding vector contains more than 256 names");
+ }
+ if (strcmp (mp->ps->t1_buf_array, notdef) != 0)
+ mp->ps->t1_builtin_glyph_names[counter] = mp_xstrdup (mp,mp->ps->t1_buf_array);
+ counter++;
+ }
+ if (*r != 10 && *r != '%') {
+ if (str_prefix (r, "] def")
+ || str_prefix (r, "] readonly def"))
+ break;
+ else {
+ char s[128];
+ remove_eol (r, mp->ps->t1_line_array);
+ mp_snprintf(s,128,"a name or `] def' or `] readonly def' expected: `%s'",
+ mp->ps->t1_line_array);
+ mp_fatal_error(mp,s);
+ }
+ }
+ t1_getline (mp);
+ r = mp->ps->t1_line_array;
+ }
+ } else { /* the second case */
+ p = strchr (mp->ps->t1_line_array, 10);
+ for (;p!=NULL;) {
+ if (*p == 10) {
+ t1_getline (mp);
+ p = mp->ps->t1_line_array;
+ }
+ /*
+ check for `dup <index> <glyph> put'
+ */
+ if (sscanf (p, "dup %i%256s put", &i, mp->ps->t1_buf_array) == 2 &&
+ *mp->ps->t1_buf_array == '/' && valid_code (i)) {
+ if (strcmp (mp->ps->t1_buf_array + 1, notdef) != 0)
+ mp->ps->t1_builtin_glyph_names[i] =
+ mp_xstrdup (mp,mp->ps->t1_buf_array + 1);
+ p = strstr (p, " put") + strlen (" put");
+ skip (p, ' ');
+ }
+ /*
+ check for `dup dup <to> exch <from> get put'
+ */
+ else if (sscanf (p, "dup dup %i exch %i get put", &b, &a) == 2
+ && valid_code (a) && valid_code (b)) {
+ copy_glyph_names (mp,mp->ps->t1_builtin_glyph_names, a, b);
+ p = strstr (p, " get put") + strlen (" get put");
+ skip (p, ' ');
+ }
+ /*
+ check for `dup dup <from> <size> getinterval <to> exch putinterval'
+ */
+ else if (sscanf
+ (p, "dup dup %i %i getinterval %i exch putinterval",
+ &a, &c, &b) == 3 && valid_code (a) && valid_code (b)
+ && valid_code (c)) {
+ for (i = 0; i < c; i++)
+ copy_glyph_names (mp,mp->ps->t1_builtin_glyph_names, a + i, b + i);
+ p = strstr (p, " putinterval") + strlen (" putinterval");
+ skip (p, ' ');
+ }
+ /*
+ check for `def' or `readonly def'
+ */
+ else if ((p == mp->ps->t1_line_array || (p > mp->ps->t1_line_array && p[-1] == ' '))
+ && strcmp (p, "def\n") == 0)
+ return;
+ /*
+ skip an unrecognizable word
+ */
+ else {
+ while (*p != ' ' && *p != 10)
+ p++;
+ skip (p, ' ');
+ }
+ }
+ }
+}
+
+static void t1_check_end (MP mp) {
+ if (t1_eof ())
+ return;
+ t1_getline (mp);
+ if (t1_prefix ("{restore}"))
+ t1_putline (mp);
+}
+
+@ @<Types...@>=
+typedef struct {
+ char *ff_name; /* base name of font file */
+ char *ff_path; /* full path to font file */
+} ff_entry;
+
+@ @c
+static boolean t1_open_fontfile (MP mp, fm_entry *fm_cur,const char *open_name_prefix) {
+ ff_entry *ff;
+ ff = check_ff_exist (mp, fm_cur);
+ mp->ps->t1_file = NULL;
+ if (ff->ff_path != NULL) {
+ mp->ps->t1_file = (mp->open_file)(mp,ff->ff_path, "r", mp_filetype_font);
+ }
+ if (mp->ps->t1_file == NULL) {
+ mp_warn (mp, "cannot open Type 1 font file for reading");
+ return false;
+ }
+ t1_init_params (mp,open_name_prefix,fm_cur->ff_name);
+ mp->ps->fontfile_found = true;
+ return true;
+}
+
+static void t1_scan_only (MP mp, font_number tex_font, fm_entry *fm_cur) {
+ do {
+ t1_getline (mp);
+ t1_scan_param (mp,tex_font, fm_cur);
+ }
+ while (mp->ps->t1_in_eexec == 0);
+ t1_start_eexec (mp,fm_cur);
+ do {
+ t1_getline (mp);
+ t1_scan_param (mp,tex_font, fm_cur);
+ }
+ while (!(t1_charstrings () || t1_subrs ()));
+}
+
+static void t1_include (MP mp, font_number tex_font, fm_entry *fm_cur) {
+ do {
+ t1_getline (mp);
+ t1_scan_param (mp,tex_font, fm_cur);
+ t1_putline (mp);
+ }
+ while (mp->ps->t1_in_eexec == 0);
+ t1_start_eexec (mp,fm_cur);
+ do {
+ t1_getline (mp);
+ t1_scan_param (mp,tex_font, fm_cur);
+ t1_putline (mp);
+ }
+ while (!(t1_charstrings () || t1_subrs ()));
+ mp->ps->t1_cs = true;
+ do {
+ t1_getline (mp);
+ t1_putline (mp);
+ }
+ while (!t1_end_eexec ());
+ t1_stop_eexec (mp);
+ if (fixedcontent) { /* copy 512 zeros (not needed for PDF) */
+ do {
+ t1_getline (mp);
+ t1_putline (mp);
+ }
+ while (!t1_cleartomark ());
+ t1_check_end (mp); /* write "{restore}if" if found */
+ }
+}
+
+@
+@d check_subr(SUBR) if (SUBR >= mp->ps->subr_size || SUBR < 0) {
+ char s[128];
+ mp_snprintf(s,128,"Subrs array: entry index out of range (%i)",SUBR);
+ mp_fatal_error(mp,s);
+ }
+
+@c
+static const char **check_cs_token_pair (MP mp) {
+ const char **p = (const char **) cs_token_pairs_list;
+ for (; p[0] != NULL; ++p)
+ if (t1_buf_prefix (p[0]) && t1_buf_suffix (p[1]))
+ return p;
+ return NULL;
+}
+
+static void cs_store (MP mp, boolean is_subr) {
+ char *p;
+ cs_entry *ptr;
+ int subr;
+ for (p = mp->ps->t1_line_array, mp->ps->t1_buf_ptr = mp->ps->t1_buf_array; *p != ' ';
+ *mp->ps->t1_buf_ptr++ = *p++);
+ *mp->ps->t1_buf_ptr = 0;
+ if (is_subr) {
+ subr = (int)t1_scan_num (mp, p + 1, 0);
+ check_subr (subr);
+ ptr = mp->ps->subr_tab + subr;
+ } else {
+ ptr = mp->ps->cs_ptr++;
+ if (mp->ps->cs_ptr - mp->ps->cs_tab > mp->ps->cs_size) {
+ char s[128];
+ mp_snprintf(s,128,"CharStrings dict: more entries than dict size (%i)",mp->ps->cs_size);
+ mp_fatal_error(mp,s);
+ }
+ if (strcmp (mp->ps->t1_buf_array + 1, notdef) == 0) /* skip the slash */
+ ptr->glyph_name = (char *) notdef;
+ else
+ ptr->glyph_name = mp_xstrdup (mp,mp->ps->t1_buf_array + 1);
+ }
+ /* copy " RD " + cs data to |mp->ps->t1_buf_array| */
+ memcpy (mp->ps->t1_buf_array, mp->ps->t1_line_array + mp->ps->cs_start - 4,
+ (size_t) (mp->ps->t1_cslen + 4));
+ /* copy the end of cs data to |mp->ps->t1_buf_array| */
+ for (p = mp->ps->t1_line_array + mp->ps->cs_start + mp->ps->t1_cslen, mp->ps->t1_buf_ptr =
+ mp->ps->t1_buf_array + mp->ps->t1_cslen + 4; *p != 10; *mp->ps->t1_buf_ptr++ = *p++);
+ *mp->ps->t1_buf_ptr++ = 10;
+ if (is_subr && mp->ps->cs_token_pair == NULL)
+ mp->ps->cs_token_pair = check_cs_token_pair (mp);
+ ptr->len = (unsigned short)(mp->ps->t1_buf_ptr - mp->ps->t1_buf_array);
+ ptr->cslen = mp->ps->t1_cslen;
+ ptr->data = mp_xmalloc (mp, (size_t)ptr->len , sizeof (byte));
+ memcpy (ptr->data, mp->ps->t1_buf_array, (size_t)ptr->len);
+ ptr->valid = true;
+}
+
+#define store_subr(mp) cs_store(mp,true)
+#define store_cs(mp) cs_store(mp,false)
+
+#define CC_STACK_SIZE 24
+
+static double cc_stack[CC_STACK_SIZE], *stack_ptr = cc_stack;
+static cc_entry cc_tab[CS_MAX];
+static boolean is_cc_init = false;
+
+
+#define cc_pop(N) \
+ if (stack_ptr - cc_stack < (N)) \
+ stack_error(N); \
+ stack_ptr -= N
+
+#define stack_error(N) { \
+ char s[256]; \
+ mp_snprintf(s,255,"CharString: invalid access (%i) to stack (%i entries)", \
+ (int) N, (int)(stack_ptr - cc_stack)); \
+ mp_warn(mp,s); \
+ goto cs_error; \
+}
+
+
+#define cc_get(N) ((N) < 0 ? *(stack_ptr + (N)) : *(cc_stack + (N)))
+
+#define cc_push(V) *stack_ptr++ = (double)(V)
+#define cc_clear() stack_ptr = cc_stack
+
+#define set_cc(N, B, A, C) \
+ cc_tab[N].nargs = A; \
+ cc_tab[N].bottom = B; \
+ cc_tab[N].clear = C; \
+ cc_tab[N].valid = true
+
+static void cc_init (void) {
+ int i;
+ if (is_cc_init)
+ return;
+ for (i = 0; i < CS_MAX; i++)
+ cc_tab[i].valid = false;
+ set_cc (CS_HSTEM, true, 2, true);
+ set_cc (CS_VSTEM, true, 2, true);
+ set_cc (CS_VMOVETO, true, 1, true);
+ set_cc (CS_RLINETO, true, 2, true);
+ set_cc (CS_HLINETO, true, 1, true);
+ set_cc (CS_VLINETO, true, 1, true);
+ set_cc (CS_RRCURVETO, true, 6, true);
+ set_cc (CS_CLOSEPATH, false, 0, true);
+ set_cc (CS_CALLSUBR, false, 1, false);
+ set_cc (CS_RETURN, false, 0, false);
+ /*
+ |set_cc(CS_ESCAPE, false, 0, false);|
+ */
+ set_cc (CS_HSBW, true, 2, true);
+ set_cc (CS_ENDCHAR, false, 0, true);
+ set_cc (CS_RMOVETO, true, 2, true);
+ set_cc (CS_HMOVETO, true, 1, true);
+ set_cc (CS_VHCURVETO, true, 4, true);
+ set_cc (CS_HVCURVETO, true, 4, true);
+ set_cc (CS_DOTSECTION, false, 0, true);
+ set_cc (CS_VSTEM3, true, 6, true);
+ set_cc (CS_HSTEM3, true, 6, true);
+ set_cc (CS_SEAC, true, 5, true);
+ set_cc (CS_SBW, true, 4, true);
+ set_cc (CS_DIV, false, 2, false);
+ set_cc (CS_CALLOTHERSUBR, false, 0, false);
+ set_cc (CS_POP, false, 0, false);
+ set_cc (CS_SETCURRENTPOINT, true, 2, true);
+ is_cc_init = true;
+}
+
+@
+
+@d cs_getchar(mp) cdecrypt(*data++, &cr)
+
+@d mark_subr(mp,n) cs_mark(mp,0, n)
+@d mark_cs(mp,s) cs_mark(mp,s, 0)
+@d SMALL_BUF_SIZE 256
+
+@c
+static void cs_warn (MP mp, const char *cs_name, int subr, const char *fmt, ...) {
+ char buf[SMALL_BUF_SIZE];
+ char s[300];
+ va_list args;
+ va_start (args, fmt);
+ @= /*@@-bufferoverflowhigh@@*/ @>
+ (void)vsprintf (buf, fmt, args);
+ @= /*@@=bufferoverflowhigh@@*/ @>
+ va_end (args);
+ if (cs_name == NULL) {
+ mp_snprintf(s,299,"Subr (%i): %s", (int) subr, buf);
+ } else {
+ mp_snprintf(s,299,"CharString (/%s): %s", cs_name, buf);
+ }
+ mp_warn(mp,s);
+}
+
+static void cs_mark (MP mp, const char *cs_name, int subr)
+{
+ byte *data;
+ int i, b, cs_len;
+ integer a, a1, a2;
+ unsigned short cr;
+ static integer lastargOtherSubr3 = 3; /* the argument of last call to
+ OtherSubrs[3] */
+ cs_entry *ptr;
+ cc_entry *cc;
+ if (cs_name == NULL) {
+ check_subr (subr);
+ ptr = mp->ps->subr_tab + subr;
+ if (!ptr->valid)
+ return;
+ } else {
+ if (mp->ps->cs_notdef != NULL &&
+ (cs_name == notdef || strcmp (cs_name, notdef) == 0))
+ ptr = mp->ps->cs_notdef;
+ else {
+ for (ptr = mp->ps->cs_tab; ptr < mp->ps->cs_ptr; ptr++)
+ if (strcmp (ptr->glyph_name, cs_name) == 0)
+ break;
+ if (ptr == mp->ps->cs_ptr) {
+ char s[128];
+ mp_snprintf (s,128,"glyph `%s' undefined", cs_name);
+ mp_warn(mp,s);
+ return;
+ }
+ if (ptr->glyph_name == notdef)
+ mp->ps->cs_notdef = ptr;
+ }
+ }
+ /* only marked CharString entries and invalid entries can be skipped;
+ valid marked subrs must be parsed to keep the stack in sync */
+ if (!ptr->valid || (ptr->is_used && cs_name != NULL))
+ return;
+ ptr->is_used = true;
+ cr = 4330;
+ cs_len = (int)ptr->cslen;
+ data = ptr->data + 4;
+ for (i = 0; i < mp->ps->t1_lenIV; i++, cs_len--)
+ (void)cs_getchar (mp);
+ while (cs_len > 0) {
+ --cs_len;
+ b = cs_getchar (mp);
+ if (b >= 32) {
+ if (b <= 246)
+ a = b - 139;
+ else if (b <= 250) {
+ --cs_len;
+ a = (int)((unsigned)(b - 247) << 8) + 108 + cs_getchar (mp);
+ } else if (b <= 254) {
+ --cs_len;
+ a = -(int)((unsigned)(b - 251) << 8) - 108 - cs_getchar (mp);
+ } else {
+ cs_len -= 4;
+ a = (cs_getchar (mp) & 0xff) << 24;
+ a |= (cs_getchar (mp) & 0xff) << 16;
+ a |= (cs_getchar (mp) & 0xff) << 8;
+ a |= (cs_getchar (mp) & 0xff) << 0;
+ if (sizeof (integer) > 4 && (a & 0x80000000))
+ a |= ~0x7FFFFFFF;
+ }
+ cc_push (a);
+ } else {
+ if (b == CS_ESCAPE) {
+ b = cs_getchar (mp) + CS_1BYTE_MAX;
+ cs_len--;
+ }
+ if (b >= CS_MAX) {
+ cs_warn (mp,cs_name, subr, "command value out of range: %i",
+ (int) b);
+ goto cs_error;
+ }
+ cc = cc_tab + b;
+ if (!cc->valid) {
+ cs_warn (mp,cs_name, subr, "command not valid: %i", (int) b);
+ goto cs_error;
+ }
+ if (cc->bottom) {
+ if (stack_ptr - cc_stack < cc->nargs)
+ cs_warn (mp,cs_name, subr,
+ "less arguments on stack (%i) than required (%i)",
+ (int) (stack_ptr - cc_stack), (int) cc->nargs);
+ else if (stack_ptr - cc_stack > cc->nargs)
+ cs_warn (mp,cs_name, subr,
+ "more arguments on stack (%i) than required (%i)",
+ (int) (stack_ptr - cc_stack), (int) cc->nargs);
+ }
+ switch (cc - cc_tab) {
+ case CS_CALLSUBR:
+ a1 = (integer)cc_get (-1);
+ cc_pop (1);
+ mark_subr (mp,a1);
+ if (!mp->ps->subr_tab[a1].valid) {
+ cs_warn (mp,cs_name, subr, "cannot call subr (%i)", (int) a1);
+ goto cs_error;
+ }
+ break;
+ case CS_DIV:
+ cc_pop (2);
+ cc_push (0);
+ break;
+ case CS_CALLOTHERSUBR:
+ a1 = (integer)cc_get (-1);
+ if (a1 == 3)
+ lastargOtherSubr3 = (integer)cc_get (-3);
+ a1 = (integer)cc_get (-2) + 2;
+ cc_pop (a1);
+ break;
+ case CS_POP:
+ cc_push (lastargOtherSubr3);
+ /* the only case when we care about the value being pushed onto
+ stack is when POP follows CALLOTHERSUBR (changing hints by
+ OtherSubrs[3])
+ */
+ break;
+ case CS_SEAC:
+ a1 = (integer)cc_get (3);
+ a2 = (integer)cc_get (4);
+ cc_clear ();
+ mark_cs (mp,standard_glyph_names[a1]);
+ mark_cs (mp,standard_glyph_names[a2]);
+ break;
+ default:
+ if (cc->clear)
+ cc_clear ();
+ }
+ }
+ }
+ return;
+ cs_error: /* an error occured during parsing */
+ cc_clear ();
+ ptr->valid = false;
+ ptr->is_used = false;
+}
+
+static void t1_subset_ascii_part (MP mp, font_number tex_font, fm_entry *fm_cur)
+{
+ int i, j;
+ t1_getline (mp);
+ while (!t1_prefix ("/Encoding")) {
+ t1_scan_param (mp,tex_font, fm_cur);
+ t1_putline (mp);
+ t1_getline (mp);
+ }
+ t1_builtin_enc (mp);
+ if (is_reencoded (fm_cur))
+ mp->ps->t1_glyph_names = external_enc ();
+ else
+ mp->ps->t1_glyph_names = mp->ps->t1_builtin_glyph_names;
+ /*
+ |if (is_included (fm_cur) && is_subsetted (fm_cur)) {
+ make_subset_tag (fm_cur, t1_glyph_names, tex_font);
+ update_subset_tag ();
+ }|
+ */
+ if ((!is_subsetted (fm_cur)) && mp->ps->t1_encoding == ENC_STANDARD)
+ t1_puts (mp,"/Encoding StandardEncoding def\n");
+ else {
+ t1_puts
+ (mp,"/Encoding 256 array\n0 1 255 {1 index exch /.notdef put} for\n");
+ for (i = 0, j = 0; i < 256; i++) {
+ if (is_used_char (i) && mp->ps->t1_glyph_names[i] != notdef) {
+ j++;
+ mp_snprintf (mp->ps->t1_line_array, (int)mp->ps->t1_line_limit,
+ "dup %i /%s put\n", (int) t1_char (i),
+ mp->ps->t1_glyph_names[i]);
+ t1_puts(mp,mp->ps->t1_line_array);
+ }
+ }
+ /* We didn't mark anything for the Encoding array. */
+ /* We add "dup 0 /.notdef put" for compatibility */
+ /* with Acrobat 5.0. */
+ if (j == 0)
+ t1_puts (mp,"dup 0 /.notdef put\n");
+ t1_puts (mp,"readonly def\n");
+ }
+ do {
+ t1_getline (mp);
+ t1_scan_param (mp,tex_font, fm_cur);
+ if (!t1_prefix ("/UniqueID")) /* ignore UniqueID for subsetted fonts */
+ t1_putline (mp);
+ }
+ while (mp->ps->t1_in_eexec == 0);
+}
+
+#define t1_subr_flush(mp) t1_flush_cs(mp,true)
+#define t1_cs_flush(mp) t1_flush_cs(mp,false)
+
+static void cs_init (MP mp) {
+ mp->ps->cs_ptr = mp->ps->cs_tab = NULL;
+ mp->ps->cs_dict_start = mp->ps->cs_dict_end = NULL;
+ mp->ps->cs_count = mp->ps->cs_size = mp->ps->cs_size_pos = 0;
+ mp->ps->cs_token_pair = NULL;
+ mp->ps->subr_tab = NULL;
+ mp->ps->subr_array_start = mp->ps->subr_array_end = NULL;
+ mp->ps->subr_max = mp->ps->subr_size = mp->ps->subr_size_pos = 0;
+}
+
+static void init_cs_entry ( cs_entry * cs) {
+ cs->data = NULL;
+ cs->glyph_name = NULL;
+ cs->len = 0;
+ cs->cslen = 0;
+ cs->is_used = false;
+ cs->valid = false;
+}
+
+static void t1_mark_glyphs (MP mp, font_number tex_font);
+
+static void t1_read_subrs (MP mp, font_number tex_font, fm_entry *fm_cur, int read_only)
+{
+ int i, s;
+ cs_entry *ptr;
+ t1_getline (mp);
+ while (!(t1_charstrings () || t1_subrs ())) {
+ t1_scan_param (mp,tex_font, fm_cur);
+ if (!read_only)
+ t1_putline (mp);
+ t1_getline (mp);
+ }
+ FOUND:
+ mp->ps->t1_cs = true;
+ mp->ps->t1_scan = false;
+ if (!t1_subrs ())
+ return;
+ mp->ps->subr_size_pos = (int)(strlen ("/Subrs") + 1);
+ /* |subr_size_pos| points to the number indicating dict size after "/Subrs" */
+ mp->ps->subr_size = (int)t1_scan_num (mp,mp->ps->t1_line_array + mp->ps->subr_size_pos, 0);
+ if (mp->ps->subr_size == 0) {
+ while (!t1_charstrings ())
+ t1_getline (mp);
+ return;
+ }
+ /* |subr_tab = xtalloc (subr_size, cs_entry);| */
+ mp->ps->subr_tab = (cs_entry *)mp_xmalloc (mp,(size_t)mp->ps->subr_size, sizeof (cs_entry));
+ for (ptr = mp->ps->subr_tab; ptr - mp->ps->subr_tab < mp->ps->subr_size; ptr++)
+ init_cs_entry (ptr);
+ mp->ps->subr_array_start = mp_xstrdup (mp,mp->ps->t1_line_array);
+ t1_getline (mp);
+ while (mp->ps->t1_cslen) {
+ store_subr (mp);
+ t1_getline (mp);
+ }
+ /* mark the first four entries without parsing */
+ for (i = 0; i < mp->ps->subr_size && i < 4; i++)
+ mp->ps->subr_tab[i].is_used = true;
+ /* the end of the Subrs array might have more than one line so we need to
+ concatnate them to |subr_array_end|. Unfortunately some fonts don't have
+ the Subrs array followed by the CharStrings dict immediately (synthetic
+ fonts). If we cannot find CharStrings in next |POST_SUBRS_SCAN| lines then
+ we will treat the font as synthetic and ignore everything until next
+ Subrs is found
+ */
+#define POST_SUBRS_SCAN 5
+ s = 0;
+ *mp->ps->t1_buf_array = 0;
+ for (i = 0; i < POST_SUBRS_SCAN; i++) {
+ if (t1_charstrings ())
+ break;
+ s += mp->ps->t1_line_ptr - mp->ps->t1_line_array;
+ alloc_array (t1_buf, s, T1_BUF_SIZE);
+ strcat (mp->ps->t1_buf_array, mp->ps->t1_line_array);
+ t1_getline (mp);
+ }
+ mp->ps->subr_array_end = mp_xstrdup (mp,mp->ps->t1_buf_array);
+ if (i == POST_SUBRS_SCAN) { /* CharStrings not found;
+ suppose synthetic font */
+ for (ptr = mp->ps->subr_tab; ptr - mp->ps->subr_tab < mp->ps->subr_size; ptr++)
+ if (ptr->valid)
+ mp_xfree (ptr->data);
+ mp_xfree (mp->ps->subr_tab);
+ mp_xfree (mp->ps->subr_array_start);
+ mp_xfree (mp->ps->subr_array_end);
+ cs_init (mp);
+ mp->ps->t1_cs = false;
+ mp->ps->t1_synthetic = true;
+ while (!(t1_charstrings () || t1_subrs ()))
+ t1_getline (mp);
+ goto FOUND;
+ }
+}
+
+@ @c
+static void t1_flush_cs (MP mp, boolean is_subr)
+{
+ char *p;
+ byte *r, *return_cs = NULL;
+ cs_entry *tab, *end_tab, *ptr;
+ char *start_line, *line_end;
+ int count, size_pos;
+ unsigned short cr, cs_len = 0; /* to avoid warning about uninitialized use of |cs_len| */
+ if (is_subr) {
+ start_line = mp->ps->subr_array_start;
+ line_end = mp->ps->subr_array_end;
+ size_pos = mp->ps->subr_size_pos;
+ tab = mp->ps->subr_tab;
+ count = mp->ps->subr_max + 1;
+ end_tab = mp->ps->subr_tab + count;
+ } else {
+ start_line = mp->ps->cs_dict_start;
+ line_end = mp->ps->cs_dict_end;
+ size_pos = mp->ps->cs_size_pos;
+ tab = mp->ps->cs_tab;
+ end_tab = mp->ps->cs_ptr;
+ count = mp->ps->cs_count;
+ }
+ mp->ps->t1_line_ptr = mp->ps->t1_line_array;
+ for (p = start_line; p - start_line < size_pos;)
+ *mp->ps->t1_line_ptr++ = *p++;
+ while (mp_isdigit (*p))
+ p++;
+ mp_snprintf (mp->ps->t1_line_ptr, (int)mp->ps->t1_line_limit, "%u", (unsigned)count);
+ strcat (mp->ps->t1_line_ptr, p);
+ mp->ps->t1_line_ptr = eol (mp->ps->t1_line_array);
+ t1_putline (mp);
+
+ /* create |return_cs| to replace unsused subr's */
+ if (is_subr) {
+ cr = 4330;
+ cs_len = 0;
+ return_cs = mp_xmalloc (mp, (size_t)(mp->ps->t1_lenIV + 1) , sizeof(byte));
+ if ( mp->ps->t1_lenIV >= 0) {
+ for (cs_len = 0, r = return_cs;
+ cs_len<(unsigned short)mp->ps->t1_lenIV; cs_len++, r++)
+ *r = cencrypt (0x00, &cr);
+ *r = cencrypt (CS_RETURN, &cr);
+ } else {
+ *return_cs = CS_RETURN;
+ }
+ cs_len++;
+ }
+
+ for (ptr = tab; ptr < end_tab; ptr++) {
+ if (ptr->is_used) {
+ if (is_subr)
+ mp_snprintf (mp->ps->t1_line_array, (int)mp->ps->t1_line_limit,
+ "dup %i %u", (int) (ptr - tab), ptr->cslen);
+ else
+ mp_snprintf (mp->ps->t1_line_array, (int)mp->ps->t1_line_limit,
+ "/%s %u", ptr->glyph_name, ptr->cslen);
+ p = strend (mp->ps->t1_line_array);
+ memcpy (p, ptr->data, (size_t)ptr->len);
+ mp->ps->t1_line_ptr = p + ptr->len;
+ t1_putline (mp);
+ } else {
+ /* replace unsused subr's by |return_cs| */
+ if (is_subr) {
+ mp_snprintf (mp->ps->t1_line_array, (int)mp->ps->t1_line_limit,
+ "dup %i %u%s ", (int) (ptr - tab),
+ cs_len, mp->ps->cs_token_pair[0]);
+ p = strend (mp->ps->t1_line_array);
+ memcpy (p, return_cs, (size_t)cs_len);
+ mp->ps->t1_line_ptr = p + cs_len;
+ t1_putline (mp);
+ mp_snprintf (mp->ps->t1_line_array, (int)mp->ps->t1_line_limit,
+ " %s", mp->ps->cs_token_pair[1]);
+ mp->ps->t1_line_ptr = eol (mp->ps->t1_line_array);
+ t1_putline (mp);
+ }
+ }
+ mp_xfree (ptr->data);
+ if (ptr->glyph_name != notdef)
+ mp_xfree (ptr->glyph_name);
+ }
+ mp_snprintf (mp->ps->t1_line_array, (int)mp->ps->t1_line_limit, "%s", line_end);
+ mp->ps->t1_line_ptr = eol (mp->ps->t1_line_array);
+ t1_putline (mp);
+ if (is_subr)
+ mp_xfree (return_cs);
+ mp_xfree (tab);
+ mp_xfree (start_line);
+ mp_xfree (line_end);
+}
+
+static void t1_mark_glyphs (MP mp, font_number tex_font)
+{
+ int i;
+ char *charset = extra_charset ();
+ char *g, *s, *r;
+ cs_entry *ptr;
+ if (mp->ps->t1_synthetic || embed_all_glyphs (tex_font)) { /* mark everything */
+ if (mp->ps->cs_tab != NULL)
+ for (ptr = mp->ps->cs_tab; ptr < mp->ps->cs_ptr; ptr++)
+ if (ptr->valid)
+ ptr->is_used = true;
+ if (mp->ps->subr_tab != NULL) {
+ for (ptr = mp->ps->subr_tab; ptr - mp->ps->subr_tab < mp->ps->subr_size; ptr++)
+ if (ptr->valid)
+ ptr->is_used = true;
+ mp->ps->subr_max = mp->ps->subr_size - 1;
+ }
+ return;
+ }
+ mark_cs (mp,notdef);
+ for (i = 0; i < 256; i++)
+ if (is_used_char (i)) {
+ if (mp->ps->t1_glyph_names[i] == notdef) {
+ char S[128];
+ mp_snprintf(S,128, "character %i is mapped to %s", i, notdef);
+ mp_warn(mp,S);
+ } else
+ mark_cs (mp,mp->ps->t1_glyph_names[i]);
+ }
+ if (charset == NULL)
+ goto SET_SUBR_MAX;
+ g = s = charset + 1; /* skip the first '/' */
+ r = strend (g);
+ while (g < r) {
+ while (*s != '/' && s < r)
+ s++;
+ *s = 0; /* terminate g by rewriting '/' to 0 */
+ mark_cs (mp,g);
+ g = s + 1;
+ }
+ SET_SUBR_MAX:
+ if (mp->ps->subr_tab != NULL)
+ for (mp->ps->subr_max = -1, ptr = mp->ps->subr_tab;
+ ptr - mp->ps->subr_tab < mp->ps->subr_size;
+ ptr++)
+ if (ptr->is_used && ptr - mp->ps->subr_tab > mp->ps->subr_max)
+ mp->ps->subr_max = ptr - mp->ps->subr_tab;
+}
+
+static void t1_do_subset_charstrings (MP mp, font_number tex_font)
+{
+ cs_entry *ptr;
+ mp->ps->cs_size_pos =
+ strstr (mp->ps->t1_line_array, charstringname) + strlen (charstringname)
+ - mp->ps->t1_line_array + 1;
+ /* |cs_size_pos| points to the number indicating
+ dict size after "/CharStrings" */
+ mp->ps->cs_size = (int)t1_scan_num (mp,mp->ps->t1_line_array + mp->ps->cs_size_pos, 0);
+ mp->ps->cs_ptr = mp->ps->cs_tab = mp_xmalloc (mp,(size_t)mp->ps->cs_size, sizeof(cs_entry));
+ for (ptr = mp->ps->cs_tab; ptr - mp->ps->cs_tab < mp->ps->cs_size; ptr++)
+ init_cs_entry (ptr);
+ mp->ps->cs_notdef = NULL;
+ mp->ps->cs_dict_start = mp_xstrdup (mp,mp->ps->t1_line_array);
+ t1_getline (mp);
+ while (mp->ps->t1_cslen) {
+ store_cs (mp);
+ t1_getline (mp);
+ }
+ mp->ps->cs_dict_end = mp_xstrdup (mp,mp->ps->t1_line_array);
+ t1_mark_glyphs (mp,tex_font);
+}
+
+static void t1_subset_charstrings (MP mp, font_number tex_font)
+{
+ cs_entry *ptr;
+ t1_do_subset_charstrings (mp, tex_font);
+ if (mp->ps->subr_tab != NULL) {
+ if (mp->ps->cs_token_pair == NULL)
+ mp_fatal_error
+ (mp, "This Type 1 font uses mismatched subroutine begin/end token pairs.");
+ t1_subr_flush (mp);
+ }
+ for (mp->ps->cs_count = 0, ptr = mp->ps->cs_tab; ptr < mp->ps->cs_ptr; ptr++)
+ if (ptr->is_used)
+ mp->ps->cs_count++;
+ t1_cs_flush (mp);
+}
+
+static void t1_subset_end (MP mp)
+{
+ if (mp->ps->t1_synthetic) { /* copy to "dup /FontName get exch definefont pop" */
+ while (!strstr (mp->ps->t1_line_array, "definefont")) {
+ t1_getline (mp);
+ t1_putline (mp);
+ }
+ while (!t1_end_eexec ())
+ t1_getline (mp); /* ignore the rest */
+ t1_putline (mp); /* write "mark currentfile closefile" */
+ } else
+ while (!t1_end_eexec ()) { /* copy to "mark currentfile closefile" */
+ t1_getline (mp);
+ t1_putline (mp);
+ }
+ t1_stop_eexec (mp);
+ if (fixedcontent) { /* copy 512 zeros (not needed for PDF) */
+ while (!t1_cleartomark ()) {
+ t1_getline (mp);
+ t1_putline (mp);
+ }
+ if (!mp->ps->t1_synthetic) /* don't check "{restore}if" for synthetic fonts */
+ t1_check_end (mp); /* write "{restore}if" if found */
+ }
+}
+
+static int t1_updatefm (MP mp, font_number f, fm_entry *fm)
+{
+ char *s, *p;
+ mp->ps->read_encoding_only = true;
+ if (!t1_open_fontfile (mp,fm,NULL)) {
+ return 0;
+ }
+ t1_scan_only (mp,f, fm);
+ s = mp_xstrdup(mp,mp->ps->fontname_buf);
+ p = s;
+ while (*p != ' ' && *p != 0)
+ p++;
+ *p=0;
+ fm->ps_name = s;
+ t1_close_font_file (mp,"");
+ return 1;
+}
+
+
+static void writet1 (MP mp, font_number tex_font, fm_entry *fm_cur) {
+ unsigned save_selector = mp->selector;
+ mp_normalize_selector(mp);
+ mp->ps->read_encoding_only = false;
+ if (!is_included (fm_cur)) { /* scan parameters from font file */
+ if (!t1_open_fontfile (mp,fm_cur,"{"))
+ return;
+ t1_scan_only (mp,tex_font, fm_cur);
+ t1_close_font_file (mp,"}");
+ return;
+ }
+ if (!is_subsetted (fm_cur)) { /* include entire font */
+ if (!t1_open_fontfile (mp,fm_cur,"<<"))
+ return;
+ t1_include (mp,tex_font,fm_cur);
+ t1_close_font_file (mp,">>");
+ return;
+ }
+ /* partial downloading */
+ if (!t1_open_fontfile (mp,fm_cur,"<"))
+ return;
+ t1_subset_ascii_part (mp,tex_font,fm_cur);
+ t1_start_eexec (mp,fm_cur);
+ cc_init ();
+ cs_init (mp);
+ t1_read_subrs (mp,tex_font, fm_cur, false);
+ t1_subset_charstrings (mp,tex_font);
+ t1_subset_end (mp);
+ t1_close_font_file (mp,">");
+ mp->selector = save_selector;
+}
+
+@ @<Declarations@>=
+static void t1_free (MP mp);
+
+@ @c
+static void t1_free (MP mp) {
+ mp_xfree (mp->ps->t1_line_array);
+ mp_xfree (mp->ps->t1_buf_array);
+}
+
+@* Embedding Charstrings.
+
+The SVG backend uses some routines that use an ascii representation of
+a type1 font. First, here is the type associated with it:
+
+@<Types ...@>=
+typedef struct mp_ps_font {
+ int font_num; /* just to put something in */
+ char **t1_glyph_names;
+ cs_entry *cs_tab;
+ cs_entry *cs_ptr;
+ cs_entry *subr_tab;
+ int t1_lenIV;
+ int slant;
+ int extend;
+ @<Variables for the charstring parser@>
+} mp_ps_font;
+
+@ The parser creates a structure and fills it.
+
+@c
+
+mp_ps_font *mp_ps_font_parse (MP mp, int tex_font) {
+ mp_ps_font *f;
+ fm_entry *fm_cur;
+ char msg[128];
+ (void)mp_has_fm_entry (mp, tex_font, &fm_cur);
+ if (fm_cur == NULL) {
+ mp_snprintf(msg,128,"fontmap entry for `%s' not found", mp->font_name[tex_font]);
+ mp_warn(mp,msg);
+ return NULL;
+ }
+ if (is_truetype(fm_cur) ||
+ (fm_cur->ps_name == NULL && fm_cur->ff_name == NULL) ||
+ (!is_included(fm_cur))) {
+ mp_snprintf(msg,128,"font `%s' cannot be embedded", mp->font_name[tex_font]);
+ mp_warn(mp,msg);
+ return NULL;
+ }
+ if (!t1_open_fontfile (mp,fm_cur,"<")) { /* message handled there */
+ return NULL;
+ }
+ f = mp_xmalloc(mp, 1, sizeof(struct mp_ps_font));
+ f->font_num = tex_font;
+ f->t1_glyph_names = NULL;
+ f->cs_tab = NULL;
+ f->cs_ptr = NULL;
+ f->subr_tab = NULL;
+ f->orig_x = f->orig_y = 0.0;
+ f->slant = (int)fm_cur->slant;
+ f->extend = (int)fm_cur->extend;
+ t1_getline (mp);
+ while (!t1_prefix ("/Encoding")) {
+ t1_scan_param (mp,tex_font, fm_cur);
+ t1_getline (mp);
+ }
+ t1_builtin_enc (mp);
+ if (is_reencoded (fm_cur)) {
+ mp_read_enc (mp, fm_cur->encoding);;
+ f->t1_glyph_names = external_enc ();
+ } else {
+ f->t1_glyph_names = mp->ps->t1_builtin_glyph_names;
+ }
+ do {
+ t1_getline (mp);
+ t1_scan_param (mp,tex_font, fm_cur);
+ } while (mp->ps->t1_in_eexec == 0);
+
+ /* t1_start_eexec (mp,fm_cur); */
+ cc_init ();
+ cs_init (mp);
+ /* the boolean is needed to make sure that |t1_read_subrs|
+ doesn't output stuff */
+ t1_read_subrs (mp,tex_font, fm_cur, true);
+ mp->ps->t1_synthetic = true ;
+ t1_do_subset_charstrings (mp, tex_font);
+ f->cs_tab = mp->ps->cs_tab;
+ mp->ps->cs_tab = NULL;
+ f->cs_ptr = mp->ps->cs_ptr;
+ mp->ps->cs_ptr = NULL;
+ f->subr_tab = mp->ps->subr_tab;
+ mp->ps->subr_tab = NULL;
+ f->t1_lenIV = mp->ps->t1_lenIV;
+ t1_close_font_file (mp,">");
+ return f;
+}
+
+@ @<Exported function headers@>=
+mp_ps_font *mp_ps_font_parse (MP mp, int tex_font);
+
+@ Freeing the structure
+
+@c
+void mp_ps_font_free (MP mp, mp_ps_font *f) {
+ (void)mp;
+ mp_xfree(f);
+}
+
+@ @<Exported function headers@>=
+void mp_ps_font_free (MP mp, mp_ps_font *f);
+
+
+@ Parsing Charstrings.
+
+@<Variables for the charstring parser@>=
+double cur_x, cur_y; /* current point */
+double orig_x, orig_y; /* origin (for seac) */
+mp_edge_object *h; /* the whole picture */
+mp_graphic_object *p; /* the current subpath in the picture */
+mp_knot *pp; /* the last known knot in the subpath */
+
+
+@ @c
+mp_edge_object *mp_ps_font_charstring (MP mp, mp_ps_font *f, int c) {
+ mp_edge_object *h = NULL;
+ f->h = NULL; f->p = NULL; f->pp = NULL; /* just in case */
+ f->cur_x = f->cur_y = 0.0;
+ f->orig_x = f->orig_y = 0.0;
+ if (cs_parse(mp,f,f->t1_glyph_names[c], 0)) {
+ h = f->h;
+ } else {
+ if (f->h != NULL) {
+ finish_subpath();
+ mp_gr_toss_objects(f->h);
+ }
+ }
+ f->h = NULL; f->p = NULL; f->pp = NULL;
+ return h;
+}
+
+
+
+@ @<Exported function headers@>=
+mp_edge_object *mp_ps_font_charstring (MP mp, mp_ps_font *f, int c);
+
+
+@
+@<Declarations@>=
+boolean cs_parse (MP mp, mp_ps_font *f, const char *cs_name, int subr);
+
+@
+@d scaled_from_double(a) (scaled)((a)*65536.0)
+@d double_from_scaled(a) (double)((a)/65536.0)
+
+@d start_subpath(f,dx,dy) do {
+ assert(f->pp == NULL);
+ assert(f->p == NULL);
+ f->pp = mp_xmalloc(mp, 1, sizeof (mp_knot));
+ f->pp->left_type = mp_endpoint;
+ f->pp->right_type = mp_open;
+ f->pp->x_coord = scaled_from_double(f->cur_x + dx);
+ f->pp->y_coord = scaled_from_double(f->cur_y + dy);
+ f->pp->left_x = f->pp->right_x = f->pp->x_coord;
+ f->pp->left_y = f->pp->right_y = f->pp->y_coord;
+ f->pp->next = NULL;
+ f->cur_x += dx;
+ f->cur_y += dy;
+ f->p = mp_new_graphic_object(mp,mp_fill_code);
+ gr_path_p((mp_fill_object *)f->p) = f->pp;
+} while (0)
+
+@d finish_subpath() do {
+ if (f->p != NULL) {
+ if (f->h->body == NULL) {
+ f->h->body = f->p;
+ } else {
+ mp_graphic_object *q = f->h->body;
+ while (gr_link(q) != NULL)
+ q = gr_link(q);
+ q->next = f->p;
+ }
+ }
+ f->p = NULL;
+ f->pp = NULL;
+} while (0)
+
+@d add_line_segment(f,dx,dy) do {
+ assert(f->pp != NULL);
+ n = mp_xmalloc(mp,1, sizeof (mp_knot));
+ n->left_type = mp_open;
+ n->right_type = mp_endpoint;
+ n->next = gr_path_p((mp_fill_object *)f->p); /* loop */
+ n->x_coord = scaled_from_double(f->cur_x + dx);
+ n->y_coord = scaled_from_double(f->cur_y + dy);
+ n->right_x = n->x_coord;
+ n->right_y = n->y_coord;
+ n->left_x = n->x_coord;
+ n->left_y = n->y_coord;
+ f->pp->right_type = mp_open;
+ f->pp->next = n;
+ f->pp = n;
+ f->cur_x += dx;
+ f->cur_y += dy;
+} while (0)
+
+@d add_curve_segment(f,dx1,dy1,dx2,dy2,dx3,dy3) do {
+ n = mp_xmalloc(mp, 1, sizeof (mp_knot));
+ n->left_type = mp_open;
+ n->right_type = mp_endpoint;
+ n->next = gr_path_p((mp_fill_object *)f->p); /* loop */
+ n->x_coord = scaled_from_double(f->cur_x + dx1 + dx2 + dx3);
+ n->y_coord = scaled_from_double(f->cur_y + dy1 + dy2 + dy3);
+ n->right_x = n->x_coord;
+ n->right_y = n->y_coord;
+ n->left_x = scaled_from_double(f->cur_x + dx1 + dx2);
+ n->left_y = scaled_from_double(f->cur_y + dy1 + dy2);
+ f->pp->right_x = scaled_from_double(f->cur_x + dx1);
+ f->pp->right_y = scaled_from_double(f->cur_y + dy1);
+ f->pp->right_type = mp_open;
+ f->pp->next = n;
+ f->pp = n;
+ f->cur_x += dx1 + dx2 + dx3;
+ f->cur_y += dy1 + dy2 + dy3;
+} while (0)
+
+@d cs_no_debug(A) cs_do_debug(mp,f,A,#A)
+@d cs_debug(A)
+
+@c
+
+void cs_do_debug (MP mp, mp_ps_font *f, int i, char *s) {
+ int n = cc_tab[i].nargs;
+ (void)mp; /* for -Wall */
+ (void)f; /* for -Wall */
+ while (n>0) {
+ fprintf (stdout,"%d ", (int)cc_get((-n)));
+ n--;
+ }
+ fprintf (stdout,"%s\n", s);
+}
+
+boolean cs_parse (MP mp, mp_ps_font *f, const char *cs_name, int subr)
+{
+ byte *data;
+ int i, b, cs_len;
+ integer a, a1, a2;
+ unsigned short cr;
+ static integer lastargOtherSubr3 = 3;
+
+ cs_entry *ptr;
+ cc_entry *cc;
+ mp_knot *n;
+
+ if (cs_name == NULL) {
+ ptr = f->subr_tab + subr;
+ } else {
+ i = 0;
+ for (ptr = f->cs_tab; ptr < f->cs_ptr; ptr++, i++) {
+ if (strcmp (ptr->glyph_name, cs_name) == 0)
+ break;
+ }
+ ptr = f->cs_tab+i; /* this is the right charstring */
+ }
+
+ data = ptr->data + 4;
+ cr = 4330;
+ cs_len = (int)ptr->cslen;
+ for (i = 0; i < f->t1_lenIV; i++, cs_len--)
+ (void)cs_getchar (mp);
+
+ while (cs_len > 0) {
+ --cs_len;
+ b = cs_getchar(mp);
+ if (b >= 32) {
+ if (b <= 246)
+ a = b - 139;
+ else if (b <= 250) {
+ --cs_len;
+ a = (int)((unsigned)(b - 247) << 8) + 108 + cs_getchar (mp);
+ } else if (b <= 254) {
+ --cs_len;
+ a = -(int)((unsigned)(b - 251) << 8) - 108 - cs_getchar (mp);
+ } else {
+ cs_len -= 4;
+ a = (cs_getchar (mp) & 0xff) << 24;
+ a |= (cs_getchar (mp) & 0xff) << 16;
+ a |= (cs_getchar (mp) & 0xff) << 8;
+ a |= (cs_getchar (mp) & 0xff) << 0;
+ if (sizeof (integer) > 4 && (a & 0x80000000))
+ a |= ~0x7FFFFFFF;
+ }
+ cc_push (a);
+ } else {
+ if (b == CS_ESCAPE) {
+ b = cs_getchar (mp) + CS_1BYTE_MAX;
+ cs_len--;
+ }
+ if (b >= CS_MAX) {
+ cs_warn (mp,cs_name, subr, "command value out of range: %i",
+ (int) b);
+ goto cs_error;
+ }
+ cc = cc_tab + b;
+ if (!cc->valid) {
+ cs_warn (mp,cs_name, subr, "command not valid: %i", (int) b);
+ goto cs_error;
+ }
+ if (cc->bottom) {
+ if (stack_ptr - cc_stack < cc->nargs)
+ cs_warn (mp,cs_name, subr,
+ "less arguments on stack (%i) than required (%i)",
+ (int) (stack_ptr - cc_stack), (int) cc->nargs);
+ else if (stack_ptr - cc_stack > cc->nargs)
+ cs_warn (mp,cs_name, subr,
+ "more arguments on stack (%i) than required (%i)",
+ (int) (stack_ptr - cc_stack), (int) cc->nargs);
+ }
+ switch (cc - cc_tab) {
+ case CS_CLOSEPATH: /* - CLOSEPATH |- */
+ cs_debug(CS_CLOSEPATH);
+ finish_subpath();
+ cc_clear ();
+ break;
+ case CS_HLINETO: /* |- dx HLINETO |- */
+ cs_debug(CS_HLINETO);
+ add_line_segment(f,cc_get(-1),0);
+ cc_clear ();
+ break;
+ case CS_HVCURVETO: /* |- dx1 dx2 dy2 dy3 HVCURVETO |- */
+ cs_debug(CS_HVCURVETO);
+ add_curve_segment(f,cc_get(-4),0,cc_get(-3),cc_get(-2),0,cc_get(-1));
+ cc_clear ();
+ break;
+ case CS_RLINETO: /* |- dx dy RLINETO |- */
+ cs_debug(CS_RLINETO);
+ add_line_segment(f,cc_get(-2),cc_get(-1));
+ cc_clear ();
+ break;
+ case CS_RRCURVETO: /* |- dx1 dy1 dx2 dy2 dx3 dy3 RRCURVETO |- */
+ cs_debug(CS_RRCURVETO);
+ add_curve_segment(f,cc_get(-6),cc_get(-5),cc_get(-4),cc_get(-3),cc_get(-2),cc_get(-1));
+ cc_clear ();
+ break;
+ case CS_VHCURVETO: /* |- dy1 dx2 dy2 dx3 VHCURVETO |- */
+ cs_debug(CS_VHCURVETO);
+ add_curve_segment(f,0, cc_get(-4),cc_get(-3),cc_get(-2),cc_get(-1),0);
+ cc_clear ();
+ break;
+ case CS_VLINETO: /* |- dy VLINETO |- */
+ cs_debug(CS_VLINETO);
+ add_line_segment(f,0,cc_get(-1));
+ cc_clear ();
+ break;
+ case CS_HMOVETO: /* |- dx HMOVETO |- */
+ cs_debug(CS_HMOVETO);
+ finish_subpath();
+ start_subpath(f,cc_get(-1),0);
+ cc_clear ();
+ break;
+ case CS_RMOVETO: /* |- dx dy RMOVETO |- */
+ cs_debug(CS_RMOVETO);
+ finish_subpath();
+ start_subpath(f,cc_get(-2),cc_get(-1));
+ cc_clear ();
+ break;
+ case CS_VMOVETO: /* |- dy VMOVETO |- */
+ cs_debug(CS_VMOVETO);
+ finish_subpath();
+ start_subpath(f,0,cc_get(-1));
+ cc_clear ();
+ break;
+ /* hinting commands */
+ case CS_DOTSECTION: /* - DOTSECTION |- */
+ cs_debug(CS_DOTSECTION);
+ cc_clear ();
+ break;
+ case CS_HSTEM: /* |- y dy HSTEM |- */
+ cs_debug(CS_HSTEM);
+ cc_clear ();
+ break;
+ case CS_HSTEM3: /* |- y0 dy0 y1 dy1 y2 dy2 HSTEM3 |- */
+ cs_debug(CS_HSTEM3);
+ cc_clear ();
+ break;
+ case CS_VSTEM: /* |- x dx VSTEM |- */
+ cs_debug(CS_VSTEM);
+ cc_clear ();
+ break;
+ case CS_VSTEM3: /* |- x0 dx0 x1 dx1 x2 dx2 VSTEM3 |- */
+ cs_debug(CS_VSTEM3);
+ cc_clear ();
+ break;
+ /* start and close commands */
+ case CS_SEAC: /* |- asb adx ady bchar achar SEAC |- */
+ cs_debug(CS_SEAC);
+ { double adx, ady;
+ adx = cc_get (1);
+ ady = cc_get (2);
+ a1 = (integer)cc_get (3);
+ a2 = (integer)cc_get (4);
+ cc_clear ();
+ (void)cs_parse(mp,f,standard_glyph_names[a1],0); /* base */
+ f->orig_x += adx;
+ f->orig_y += ady;
+ (void)cs_parse(mp,f,standard_glyph_names[a2],0);
+ }
+ break;
+ case CS_ENDCHAR: /* - ENDCHAR |- */
+ cs_debug(CS_ENDCHAR);
+ cc_clear ();
+ return true;
+ break;
+ case CS_HSBW: /* |- sbx wx HSBW |- */
+ cs_debug(CS_HSBW);
+ f->h = mp_xmalloc(mp, 1,sizeof(mp_edge_object));
+ f->h->body = NULL; f->h->next = NULL;
+ f->h->parent = mp;
+ f->h->filename = NULL;
+ f->h->minx = f->h->miny = f->h->maxx = f->h->maxy = 0;
+ f->cur_x = cc_get(-2) + f->orig_x;
+ f->cur_y = 0.0 + f->orig_y;
+ f->orig_x = f->cur_x;
+ f->orig_y = f->cur_y;
+ cc_clear ();
+ break;
+ case CS_SBW: /* |- sbx sby wx wy SBW |- */
+ cs_debug(CS_SBW);
+ f->h = mp_xmalloc(mp, 1,sizeof(mp_edge_object));
+ f->h->body = NULL; f->h->next = NULL;
+ f->h->parent = mp;
+ f->h->filename = NULL;
+ f->h->minx = f->h->miny = f->h->maxx = f->h->maxy = 0;
+ f->cur_x = cc_get(-4) + f->orig_x;
+ f->cur_y = cc_get(-3) + f->orig_y;
+ f->orig_x = f->cur_x;
+ f->orig_y = f->cur_y;
+ cc_clear ();
+ break;
+ /* arithmetic */
+ case CS_DIV: /* num1 num2 DIV quotient */
+ cs_debug(CS_DIV);
+ { double num,den,res;
+ num = cc_get (-2);
+ den = cc_get (-1);
+ res = num/den;
+ cc_pop (2);
+ cc_push (res);
+ break;
+ }
+ /* subrs */
+ case CS_CALLSUBR: /* subr CALLSUBR - */
+ cs_debug(CS_CALLSUBR);
+ a1 = (integer)cc_get (-1);
+ cc_pop (1);
+ (void)cs_parse(mp,f,NULL,a1);
+ break;
+ case CS_RETURN: /* - RETURN - */
+ cs_debug(CS_RETURN);
+ return true;
+ break;
+ case CS_CALLOTHERSUBR: /* arg1 ... argn n othersubr CALLOTHERSUBR - */
+ a1 = (integer)cc_get (-1);
+ if (a1 == 3)
+ lastargOtherSubr3 = (integer)cc_get (-3);
+ a1 = (integer)cc_get(-2) + 2;
+ cc_pop (a1);
+ break;
+ case CS_POP: /* - POP number */
+ cc_push (lastargOtherSubr3);
+ break;
+ case CS_SETCURRENTPOINT: /* |- x y SETCURRENTPOINT |- */
+ cs_debug(CS_SETCURRENTPOINT);
+ f->cur_x = cc_get(-2);
+ f->cur_y = cc_get(-1);
+ f->pp = NULL;
+ cc_clear ();
+ break;
+ default:
+ if (cc->clear)
+ cc_clear ();
+ }
+ }
+ }
+ return true;
+cs_error: /* an error occured during parsing */
+ cc_clear ();
+ ptr->valid = false;
+ ptr->is_used = false;
+ return false;
+}
+
+@* \[44d] Embedding fonts.
+
+@ The |tfm_num| is officially of type |font_number|, but that
+type does not exist yet at this point in the output order.
+
+@<Types...@>=
+typedef struct {
+ char *tfm_name; /* TFM file name */
+ char *ps_name; /* PostScript name */
+ integer flags; /* font flags */
+ char *ff_name; /* font file name */
+ char *subset_tag; /* pseudoUniqueTag for subsetted font */
+ enc_entry *encoding; /* pointer to corresponding encoding */
+ unsigned int tfm_num; /* number of the TFM refering this entry */
+ unsigned short type; /* font type (T1/TTF/...) */
+ short slant; /* SlantFont */
+ short extend; /* ExtendFont */
+ integer ff_objnum; /* FontFile object number */
+ integer fn_objnum; /* FontName/BaseName object number */
+ integer fd_objnum; /* FontDescriptor object number */
+ char *charset; /* string containing used glyphs */
+ boolean all_glyphs; /* embed all glyphs? */
+ unsigned short links; /* link flags from |tfm_tree| and |ps_tree| */
+ short tfm_avail; /* flags whether a tfm is available */
+ short pid; /* Pid for truetype fonts */
+ short eid; /* Eid for truetype fonts */
+} fm_entry;
+
+
+@
+@<Glob...@>=
+#define FONTNAME_BUF_SIZE 128
+boolean fontfile_found;
+boolean is_otf_font;
+char fontname_buf[FONTNAME_BUF_SIZE];
+
+@
+@d F_INCLUDED 0x01
+@d F_SUBSETTED 0x02
+@d F_TRUETYPE 0x04
+@d F_BASEFONT 0x08
+
+@d set_included(fm) ((fm)->type |= F_INCLUDED)
+@d set_subsetted(fm) ((fm)->type |= F_SUBSETTED)
+@d set_truetype(fm) ((fm)->type |= F_TRUETYPE)
+@d set_basefont(fm) ((fm)->type |= F_BASEFONT)
+
+@d is_included(fm) ((fm)->type & F_INCLUDED)
+@d is_subsetted(fm) ((fm)->type & F_SUBSETTED)
+@d is_truetype(fm) ((fm)->type & F_TRUETYPE)
+@d is_basefont(fm) ((fm)->type & F_BASEFONT)
+@d is_reencoded(fm) ((fm)->encoding != NULL)
+@d is_fontfile(fm) (fm_fontfile(fm) != NULL)
+@d is_t1fontfile(fm) (is_fontfile(fm) && !is_truetype(fm))
+
+@d fm_slant(fm) (fm)->slant
+@d fm_extend(fm) (fm)->extend
+@d fm_fontfile(fm) (fm)->ff_name
+
+@<Declarations@>=
+static boolean mp_font_is_reencoded (MP mp, font_number f);
+static boolean mp_font_is_included (MP mp, font_number f);
+static boolean mp_font_is_subsetted (MP mp, font_number f);
+
+@ @c
+boolean mp_font_is_reencoded (MP mp, font_number f) {
+ fm_entry *fm;
+ if (mp_has_font_size(mp,f) && mp_has_fm_entry (mp, f, &fm)) {
+ if (fm != NULL
+ && (fm->ps_name != NULL)
+ && is_reencoded (fm))
+ return true;
+ }
+ return false;
+}
+boolean mp_font_is_included (MP mp, font_number f) {
+ fm_entry *fm;
+ if (mp_has_font_size(mp,f) && mp_has_fm_entry (mp, f, &fm)) {
+ if (fm != NULL
+ && (fm->ps_name != NULL && fm->ff_name != NULL)
+ && is_included (fm))
+ return true;
+ }
+ return false;
+}
+boolean mp_font_is_subsetted (MP mp, font_number f) {
+ fm_entry *fm;
+ if (mp_has_font_size(mp,f) && mp_has_fm_entry (mp, f,&fm)) {
+ if (fm != NULL
+ && (fm->ps_name != NULL && fm->ff_name != NULL)
+ && is_included (fm) && is_subsetted (fm))
+ return true;
+ }
+ return false;
+}
+
+@ @<Declarations@>=
+static char * mp_fm_encoding_name (MP mp, font_number f);
+static char * mp_fm_font_name (MP mp, font_number f);
+static char * mp_fm_font_subset_name (MP mp, font_number f);
+
+@
+@c char * mp_fm_encoding_name (MP mp, font_number f) {
+ enc_entry *e;
+ fm_entry *fm;
+ if (mp_has_fm_entry (mp, f, &fm)) {
+ if (fm != NULL && (fm->ps_name != NULL)) {
+ if (is_reencoded (fm)) {
+ e = fm->encoding;
+ if (e->enc_name!=NULL)
+ return mp_xstrdup(mp,e->enc_name);
+ } else {
+ return NULL;
+ }
+ }
+ }
+ print_err ("fontmap encoding problems for font ");
+ mp_print(mp,mp->font_name[f]);
+ mp_error(mp);
+ return NULL;
+}
+char * mp_fm_font_name (MP mp, font_number f) {
+ fm_entry *fm;
+ if (mp_has_fm_entry (mp, f,&fm)) {
+ if (fm != NULL && (fm->ps_name != NULL)) {
+ if (mp_font_is_included(mp, f) && !mp->font_ps_name_fixed[f]) {
+ /* find the real fontname, and update |ps_name| and |subset_tag| if needed */
+ if (t1_updatefm(mp,f,fm)) {
+ mp->font_ps_name_fixed[f] = true;
+ } else {
+ print_err ("font loading problems for font ");
+ mp_print(mp,mp->font_name[f]);
+ mp_error(mp);
+ }
+ }
+ return mp_xstrdup(mp,fm->ps_name);
+ }
+ }
+ print_err ("fontmap name problems for font ");
+ mp_print(mp,mp->font_name[f]);
+ mp_error(mp);
+ return NULL;
+}
+
+static char * mp_fm_font_subset_name (MP mp, font_number f) {
+ fm_entry *fm;
+ if (mp_has_fm_entry (mp, f, &fm)) {
+ if (fm != NULL && (fm->ps_name != NULL)) {
+ if (is_subsetted(fm)) {
+ char *s = mp_xmalloc(mp,strlen(fm->ps_name)+8,1);
+ mp_snprintf(s,(int)strlen(fm->ps_name)+8,"%s-%s",fm->subset_tag,fm->ps_name);
+ return s;
+ } else {
+ return mp_xstrdup(mp,fm->ps_name);
+ }
+ }
+ }
+ print_err ("fontmap name problems for font ");
+ mp_print(mp,mp->font_name[f]);
+ mp_error(mp);
+ return NULL;
+}
+
+@ @<Declarations@>=
+static integer mp_fm_font_slant (MP mp, font_number f);
+static integer mp_fm_font_extend (MP mp, font_number f);
+
+@
+@c static integer mp_fm_font_slant (MP mp, font_number f) {
+ fm_entry *fm;
+ if (mp_has_fm_entry (mp, f, &fm)) {
+ if (fm != NULL && (fm->ps_name != NULL)) {
+ return fm->slant;
+ }
+ }
+ return 0;
+}
+static integer mp_fm_font_extend (MP mp, font_number f) {
+ fm_entry *fm;
+ if (mp_has_fm_entry (mp, f, &fm)) {
+ if (fm != NULL && (fm->ps_name != NULL)) {
+ return fm->extend;
+ }
+ }
+ return 0;
+}
+
+@ @<Declarations@>=
+static boolean mp_do_ps_font (MP mp, font_number f);
+
+@ @c static boolean mp_do_ps_font (MP mp, font_number f) {
+ fm_entry *fm_cur;
+ (void)mp_has_fm_entry (mp, f, &fm_cur); /* for side effects */
+ if (fm_cur == NULL)
+ return true;
+ if (is_truetype(fm_cur) ||
+ (fm_cur->ps_name == NULL && fm_cur->ff_name == NULL)) {
+ return false;
+ }
+ if (is_included(fm_cur)) {
+ mp_ps_print_nl(mp,"%%BeginResource: font ");
+ if (is_subsetted(fm_cur)) {
+ mp_ps_print(mp, fm_cur->subset_tag);
+ mp_ps_print_char(mp,'-');
+ }
+ mp_ps_print(mp, fm_cur->ps_name);
+ mp_ps_print_ln(mp);
+ writet1 (mp,f,fm_cur);
+ mp_ps_print_nl(mp,"%%EndResource");
+ mp_ps_print_ln(mp);
+ }
+ return true;
+}
+
+@ Included subset fonts do not need and encoding vector, make
+sure we skip that case.
+
+@<Declarations@>=
+static void mp_list_used_resources (MP mp, int prologues, int procset);
+
+@ @c static void mp_list_used_resources (MP mp, int prologues, int procset) {
+ font_number f; /* fonts used in a text node or as loop counters */
+ int ff; /* a loop counter */
+ int ldf; /* the last \.{DocumentFont} listed (otherwise |null_font|) */
+ boolean firstitem;
+ if ( procset>0 )
+ mp_ps_print_nl(mp, "%%DocumentResources: procset mpost");
+ else
+ mp_ps_print_nl(mp, "%%DocumentResources: procset mpost-minimal");
+ ldf=null_font;
+ firstitem=true;
+ for (f=null_font+1;f<=mp->last_fnum;f++) {
+ if ( (mp_has_font_size(mp,f))&&(mp_font_is_reencoded(mp,f)) ) {
+ for (ff=ldf;ff>=null_font;ff--) {
+ if ( mp_has_font_size(mp,(font_number)ff) )
+ if ( mp_xstrcmp(mp->font_enc_name[f],mp->font_enc_name[ff])==0 )
+ goto FOUND;
+ }
+ if ( mp_font_is_subsetted(mp,f) )
+ goto FOUND;
+ if ( mp->ps->ps_offset+1+strlen(mp->font_enc_name[f])>
+ (size_t)mp->max_print_line )
+ mp_ps_print_nl(mp, "%%+ encoding");
+ if ( firstitem ) {
+ firstitem=false;
+ mp_ps_print_nl(mp, "%%+ encoding");
+ }
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print(mp, mp->font_enc_name[f]);
+ ldf=(int)f;
+ }
+ FOUND:
+ ;
+ }
+ ldf=null_font;
+ firstitem=true;
+ for (f=null_font+1;f<=mp->last_fnum;f++) {
+ if ( mp_has_font_size(mp,f) ) {
+ for (ff=ldf;ff>=null_font;ff--) {
+ if ( mp_has_font_size(mp,(font_number)ff) )
+ if ( mp_xstrcmp(mp->font_name[f],mp->font_name[ff])==0 )
+ goto FOUND2;
+ }
+ if ( mp->ps->ps_offset+1+strlen(mp->font_ps_name[f])>
+ (size_t)mp->max_print_line )
+ mp_ps_print_nl(mp, "%%+ font");
+ if ( firstitem ) {
+ firstitem=false;
+ mp_ps_print_nl(mp, "%%+ font");
+ }
+ mp_ps_print_char(mp, ' ');
+ if ( (prologues==3)&&
+ (mp_font_is_subsetted(mp,f)) )
+ mp_ps_print(mp, mp_fm_font_subset_name(mp,f));
+ else
+ mp_ps_print(mp, mp->font_ps_name[f]);
+ ldf=(int)f;
+ }
+ FOUND2:
+ ;
+ }
+ mp_ps_print_ln(mp);
+}
+
+@ @<Declarations@>=
+static void mp_list_supplied_resources (MP mp, int prologues, int procset);
+
+@ @c static void mp_list_supplied_resources (MP mp, int prologues, int procset) {
+ font_number f; /* fonts used in a text node or as loop counters */
+ int ff; /* a loop counter */
+ int ldf; /* the last \.{DocumentFont} listed (otherwise |null_font|) */
+ boolean firstitem;
+ if ( procset>0 )
+ mp_ps_print_nl(mp, "%%DocumentSuppliedResources: procset mpost");
+ else
+ mp_ps_print_nl(mp, "%%DocumentSuppliedResources: procset mpost-minimal");
+ ldf=null_font;
+ firstitem=true;
+ for (f=null_font+1;f<=mp->last_fnum;f++) {
+ if ( (mp_has_font_size(mp,f))&&(mp_font_is_reencoded(mp,f)) ) {
+ for (ff=ldf;ff>= null_font;ff++) {
+ if ( mp_has_font_size(mp,(font_number)ff) )
+ if ( mp_xstrcmp(mp->font_enc_name[f],mp->font_enc_name[ff])==0 )
+ goto FOUND;
+ }
+ if ( (prologues==3)&&(mp_font_is_subsetted(mp,f)))
+ goto FOUND;
+ if ( mp->ps->ps_offset+1+strlen(mp->font_enc_name[f])>(size_t)mp->max_print_line )
+ mp_ps_print_nl(mp, "%%+ encoding");
+ if ( firstitem ) {
+ firstitem=false;
+ mp_ps_print_nl(mp, "%%+ encoding");
+ }
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print(mp, mp->font_enc_name[f]);
+ ldf=(int)f;
+ }
+ FOUND:
+ ;
+ }
+ ldf=null_font;
+ firstitem=true;
+ if (prologues==3) {
+ for (f=null_font+1;f<=mp->last_fnum;f++) {
+ if ( mp_has_font_size(mp,f) ) {
+ for (ff=ldf;ff>= null_font;ff--) {
+ if ( mp_has_font_size(mp,(font_number)ff) )
+ if ( mp_xstrcmp(mp->font_name[f],mp->font_name[ff])==0 )
+ goto FOUND2;
+ }
+ if ( ! mp_font_is_included(mp,f) )
+ goto FOUND2;
+ if ( mp->ps->ps_offset+1+strlen(mp->font_ps_name[f])>(size_t)mp->max_print_line )
+ mp_ps_print_nl(mp, "%%+ font");
+ if ( firstitem ) {
+ firstitem=false;
+ mp_ps_print_nl(mp, "%%+ font");
+ }
+ mp_ps_print_char(mp, ' ');
+ if ( mp_font_is_subsetted(mp,f) )
+ mp_ps_print(mp, mp_fm_font_subset_name(mp,f));
+ else
+ mp_ps_print(mp, mp->font_ps_name[f]);
+ ldf=(int)f;
+ }
+ FOUND2:
+ ;
+ }
+ mp_ps_print_ln(mp);
+ }
+}
+
+@ @<Declarations...@>=
+static void mp_list_needed_resources (MP mp, int prologues);
+
+@ @c static void mp_list_needed_resources (MP mp, int prologues) {
+ font_number f; /* fonts used in a text node or as loop counters */
+ int ff; /* a loop counter */
+ int ldf; /* the last \.{DocumentFont} listed (otherwise |null_font|) */
+ boolean firstitem;
+ ldf=null_font;
+ firstitem=true;
+ for (f=null_font+1;f<=mp->last_fnum;f++ ) {
+ if ( mp_has_font_size(mp,f)) {
+ for (ff=ldf;ff>=null_font;ff--) {
+ if ( mp_has_font_size(mp,(font_number)ff) )
+ if ( mp_xstrcmp(mp->font_name[f],mp->font_name[ff])==0 )
+ goto FOUND;
+ };
+ if ((prologues==3)&&(mp_font_is_included(mp,f)) )
+ goto FOUND;
+ if ( mp->ps->ps_offset+1+strlen(mp->font_ps_name[f])>(size_t)mp->max_print_line )
+ mp_ps_print_nl(mp, "%%+ font");
+ if ( firstitem ) {
+ firstitem=false;
+ mp_ps_print_nl(mp, "%%DocumentNeededResources: font");
+ }
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print(mp, mp->font_ps_name[f]);
+ ldf=(int)f;
+ }
+ FOUND:
+ ;
+ }
+ if ( ! firstitem ) {
+ mp_ps_print_ln(mp);
+ ldf=null_font;
+ firstitem=true;
+ for (f=null_font+1;f<= mp->last_fnum;f++) {
+ if ( mp_has_font_size(mp,f) ) {
+ for (ff=ldf;ff>=null_font;ff-- ) {
+ if ( mp_has_font_size(mp,(font_number)ff) )
+ if ( mp_xstrcmp(mp->font_name[f],mp->font_name[ff])==0 )
+ goto FOUND2;
+ }
+ if ((prologues==3)&&(mp_font_is_included(mp,f)) )
+ goto FOUND2;
+ mp_ps_print(mp, "%%IncludeResource: font ");
+ mp_ps_print(mp, mp->font_ps_name[f]);
+ mp_ps_print_ln(mp);
+ ldf=(int)f;
+ }
+ FOUND2:
+ ;
+ }
+ }
+}
+
+@ @<Declarations@>=
+static void mp_write_font_definition (MP mp, font_number f, int prologues);
+
+@
+
+@d applied_reencoding(A) ((mp_font_is_reencoded(mp,(A)))&&
+ ((! mp_font_is_subsetted(mp,(A)))||(prologues==2)))
+
+@c static void mp_write_font_definition(MP mp, font_number f, int prologues) {
+ if ( (applied_reencoding(f))||(mp_fm_font_slant(mp,f)!=0)||
+ (mp_fm_font_extend(mp,f)!=0)||
+ (mp_xstrcmp(mp->font_name[f],"psyrgo")==0)||
+ (mp_xstrcmp(mp->font_name[f],"zpzdr-reversed")==0) ) {
+ if ( (mp_font_is_subsetted(mp,f))&&
+ (mp_font_is_included(mp,f))&&(prologues==3))
+ mp_ps_name_out(mp, mp_fm_font_subset_name(mp,f),true);
+ else
+ mp_ps_name_out(mp, mp->font_ps_name[f],true);
+ mp_ps_print(mp, " fcp");
+ mp_ps_print_ln(mp);
+ if ( applied_reencoding(f) ) {
+ mp_ps_print(mp, "/Encoding ");
+ mp_ps_print(mp, mp->font_enc_name[f]);
+ mp_ps_print(mp, " def ");
+ };
+ if ( mp_fm_font_slant(mp,f)!=0 ) {
+ mp_ps_print_int(mp, mp_fm_font_slant(mp,f));
+ mp_ps_print(mp, " SlantFont ");
+ };
+ if ( mp_fm_font_extend(mp,f)!=0 ) {
+ mp_ps_print_int(mp, mp_fm_font_extend(mp,f));
+ mp_ps_print(mp, " ExtendFont ");
+ };
+ if ( mp_xstrcmp(mp->font_name[f],"psyrgo")==0 ) {
+ mp_ps_print(mp, " 890 ScaleFont ");
+ mp_ps_print(mp, " 277 SlantFont ");
+ };
+ if ( mp_xstrcmp(mp->font_name[f],"zpzdr-reversed")==0 ) {
+ mp_ps_print(mp, " FontMatrix [-1 0 0 1 0 0] matrix concatmatrix /FontMatrix exch def ");
+ mp_ps_print(mp, "/Metrics 2 dict dup begin ");
+ mp_ps_print(mp, "/space[0 -278]def ");
+ mp_ps_print(mp, "/a12[-904 -939]def ");
+ mp_ps_print(mp, "end def ");
+ };
+ mp_ps_print(mp, "currentdict end");
+ mp_ps_print_ln(mp);
+ mp_ps_print_defined_name(mp,f,prologues);
+ mp_ps_print(mp, " exch definefont pop");
+ mp_ps_print_ln(mp);
+ }
+}
+
+@ @<Declarations@>=
+static void mp_ps_print_defined_name (MP mp, font_number f, int prologues);
+
+@
+@c static void mp_ps_print_defined_name(MP mp, font_number f, int prologues) {
+ mp_ps_print(mp, " /");
+ if ((mp_font_is_subsetted(mp,f))&&
+ (mp_font_is_included(mp,f))&&(prologues==3))
+ mp_ps_print(mp, mp_fm_font_subset_name(mp,f));
+ else
+ mp_ps_print(mp, mp->font_ps_name[f]);
+ if ( mp_xstrcmp(mp->font_name[f],"psyrgo")==0 )
+ mp_ps_print(mp, "-Slanted");
+ if ( mp_xstrcmp(mp->font_name[f],"zpzdr-reversed")==0 )
+ mp_ps_print(mp, "-Reverse");
+ if ( applied_reencoding(f) ) {
+ mp_ps_print(mp, "-");
+ mp_ps_print(mp, mp->font_enc_name[f]);
+ }
+ if ( mp_fm_font_slant(mp,f)!=0 ) {
+ mp_ps_print(mp, "-Slant_"); mp_ps_print_int(mp, mp_fm_font_slant(mp,f)) ;
+ }
+ if ( mp_fm_font_extend(mp,f)!=0 ) {
+ mp_ps_print(mp, "-Extend_"); mp_ps_print_int(mp, mp_fm_font_extend(mp,f));
+ }
+}
+
+@ @<Include encodings and fonts for edge structure~|h|@>=
+mp_font_encodings(mp,mp->last_fnum,(prologues==2));
+@<Embed fonts that are available@>
+
+@ @<Embed fonts that are available@>=
+{
+next_size=0;
+@<Make |cur_fsize| a copy of the |font_sizes| array@>;
+do {
+ done_fonts=true;
+ for (f=null_font+1;f<=mp->last_fnum;f++) {
+ if ( cur_fsize[f]!=null ) {
+ if (prologues==3 ) {
+ if ( ! mp_do_ps_font(mp,f) ) {
+ if ( mp_has_fm_entry(mp,f, NULL) ) {
+ print_err("Font embedding failed");
+ mp_error(mp);
+ }
+ }
+ }
+ cur_fsize[f]=link(cur_fsize[f]);
+ if ( cur_fsize[f]!=null ) { mp_unmark_font(mp, f); done_fonts=false; }
+ }
+ }
+ if ( ! done_fonts )
+ @<Increment |next_size| and apply |mark_string_chars| to all text nodes with
+ that size index@>;
+} while (! done_fonts);
+}
+
+@ @<Increment |next_size| and apply |mark_string_chars| to all text nodes...@>=
+{
+ next_size++;
+ mp_apply_mark_string_chars(mp, h, next_size);
+}
+
+@ We also need to keep track of which characters are used in text nodes
+in the edge structure that is being shipped out. This is done by procedures
+that use the left-over |b3| field in the |char_info| words; i.e.,
+|char_info(f)(c).b3| gives the status of character |c| in font |f|.
+
+@<Types...@>=
+enum mp_char_mark_state {mp_unused=0, mp_used};
+
+@ @<Declarations@>=
+static void mp_mark_string_chars (MP mp,font_number f, char *s, size_t l) ;
+
+@ @c
+void mp_mark_string_chars (MP mp,font_number f, char *s, size_t l) {
+ integer b; /* |char_base[f]| */
+ int bc,ec; /* only characters between these bounds are marked */
+ char *k; /* an index into string |s| */
+ b=mp->char_base[f];
+ bc=(int)mp->font_bc[f];
+ ec=(int)mp->font_ec[f];
+ k=s;
+ while (l-->0){
+ if ( (*k>=bc)&&(*k<=ec) )
+ mp->font_info[b+*k].qqqq.b3=mp_used;
+ k++;
+ }
+}
+
+
+@ @<Declarations@>=
+static void mp_unmark_font (MP mp,font_number f) ;
+
+@ @c
+void mp_unmark_font (MP mp,font_number f) {
+ int k; /* an index into |font_info| */
+ for (k= mp->char_base[f]+mp->font_bc[f];
+ k<=mp->char_base[f]+mp->font_ec[f];
+ k++)
+ mp->font_info[k].qqqq.b3=mp_unused;
+}
+
+
+@ @<Declarations@>=
+static void mp_print_improved_prologue (MP mp, mp_edge_object *h, int p1, int procset) ;
+
+@ @c
+void mp_print_improved_prologue (MP mp, mp_edge_object *h, int prologues, int procset) {
+ quarterword next_size; /* the size index for fonts being listed */
+ pointer *cur_fsize; /* current positions in |font_sizes| */
+ boolean done_fonts; /* have we finished listing the fonts in the header? */
+ font_number f; /* a font number for loops */
+ cur_fsize = mp_xmalloc(mp,(size_t)(mp->font_max+1),sizeof(pointer));
+ mp_list_used_resources(mp, prologues, procset);
+ mp_list_supplied_resources(mp, prologues, procset);
+ mp_list_needed_resources(mp, prologues);
+ mp_ps_print_nl(mp, "%%EndComments");
+ mp_ps_print_nl(mp, "%%BeginProlog");
+ if ( procset>0 )
+ mp_ps_print_nl(mp, "%%BeginResource: procset mpost");
+ else
+ mp_ps_print_nl(mp, "%%BeginResource: procset mpost-minimal");
+ mp_ps_print_nl(mp, "/bd{bind def}bind def"
+ "/fshow {exch findfont exch scalefont setfont show}bd");
+ if ( procset>0 ) @<Print the procset@>;
+ mp_ps_print_nl(mp, "/fcp{findfont dup length dict begin"
+ "{1 index/FID ne{def}{pop pop}ifelse}forall}bd");
+ mp_ps_print_nl(mp, "/fmc{FontMatrix dup length array copy dup dup}bd"
+ "/fmd{/FontMatrix exch def}bd");
+ mp_ps_print_nl(mp, "/Amul{4 -1 roll exch mul 1000 div}bd"
+ "/ExtendFont{fmc 0 get Amul 0 exch put fmd}bd");
+ mp_ps_print_nl(mp, "/ScaleFont{dup fmc 0 get"
+ " Amul 0 exch put dup dup 3 get Amul 3 exch put fmd}bd");
+ mp_ps_print_nl(mp, "/SlantFont{fmc 2 get dup 0 eq{pop 1}if"
+ " Amul FontMatrix 0 get mul 2 exch put fmd}bd");
+ mp_ps_print_nl(mp, "%%EndResource");
+ @<Include encodings and fonts for edge structure~|h|@>;
+ mp_ps_print_nl(mp, "%%EndProlog");
+ mp_ps_print_nl(mp, "%%BeginSetup");
+ mp_ps_print_ln(mp);
+ for (f=null_font+1;f<=mp->last_fnum;f++) {
+ if ( mp_has_font_size(mp,f) ) {
+ if ( mp_has_fm_entry(mp,f,NULL) ) {
+ mp_write_font_definition(mp,f, prologues);
+ mp_ps_name_out(mp, mp->font_name[f],true);
+ mp_ps_print_defined_name(mp,f, prologues);
+ mp_ps_print(mp, " def");
+ } else {
+ char s[256];
+ mp_snprintf(s,256,"font %s cannot be found in any fontmapfile!", mp->font_name[f]);
+ mp_warn(mp,s);
+ mp_ps_name_out(mp, mp->font_name[f],true);
+ mp_ps_name_out(mp, mp->font_name[f],true);
+ mp_ps_print(mp, " def");
+ }
+ mp_ps_print_ln(mp);
+ }
+ }
+ mp_ps_print_nl(mp, "%%EndSetup");
+ mp_ps_print_nl(mp, "%%Page: 1 1");
+ mp_ps_print_ln(mp);
+ mp_xfree(cur_fsize);
+}
+
+@ @<Declarations@>=
+static font_number mp_print_font_comments (MP mp , mp_edge_object *h, int prologues);
+
+
+@
+@c
+static font_number mp_print_font_comments (MP mp , mp_edge_object *h, int prologues) {
+ quarterword next_size; /* the size index for fonts being listed */
+ pointer *cur_fsize; /* current positions in |font_sizes| */
+ int ff; /* a loop counter */
+ boolean done_fonts; /* have we finished listing the fonts in the header? */
+ font_number f; /* a font number for loops */
+ scaled ds; /* design size and scale factor for a text node */
+ int ldf=0; /* the last \.{DocumentFont} listed (otherwise |null_font|) */
+ cur_fsize = mp_xmalloc(mp,(size_t)(mp->font_max+1),sizeof(pointer));
+ if ( prologues>0 ) {
+ @<Give a \.{DocumentFonts} comment listing all fonts with non-null
+ |font_sizes| and eliminate duplicates@>;
+ } else {
+ next_size=0;
+ @<Make |cur_fsize| a copy of the |font_sizes| array@>;
+ do { done_fonts=true;
+ for (f=null_font+1;f<=mp->last_fnum;f++) {
+ if ( cur_fsize[f]!=null ) {
+ @<Print the \.{\%*Font} comment for font |f| and advance |cur_fsize[f]|@>;
+ }
+ if ( cur_fsize[f]!=null ) { mp_unmark_font(mp, f); done_fonts=false; };
+ }
+ if ( ! done_fonts ) {
+ @<Increment |next_size| and apply |mark_string_chars| to all text nodes with
+ that size index@>;
+ }
+ } while (! done_fonts);
+ }
+ mp_xfree(cur_fsize);
+ return (font_number)ldf;
+}
+
+@ @<Make |cur_fsize| a copy of the |font_sizes| array@>=
+for (f=null_font+1;f<= mp->last_fnum;f++)
+ cur_fsize[f]=mp->font_sizes[f]
+
+@ It's not a good idea to make any assumptions about the |font_ps_name| entries,
+so we carefully remove duplicates. There is no harm in using a slow, brute-force
+search.
+
+@<Give a \.{DocumentFonts} comment listing all fonts with non-null...@>=
+{
+ ldf=null_font;
+ for (f=null_font+1;f<= mp->last_fnum;f++) {
+ if ( mp->font_sizes[f]!=null ) {
+ if ( ldf==null_font )
+ mp_ps_print_nl(mp, "%%DocumentFonts:");
+ for (ff=ldf;ff>=null_font;ff--) {
+ if ( mp->font_sizes[ff]!=null )
+ if ( mp_xstrcmp(mp->font_ps_name[f],mp->font_ps_name[ff])==0 )
+ goto FOUND;
+ }
+ if ( mp->ps->ps_offset+1+strlen(mp->font_ps_name[f])>(size_t)mp->max_print_line )
+ mp_ps_print_nl(mp, "%%+");
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print(mp, mp->font_ps_name[f]);
+ ldf=(int)f;
+ FOUND:
+ ;
+ }
+ }
+}
+
+@ @c
+static void mp_hex_digit_out (MP mp,quarterword d) {
+ if ( d<10 ) mp_ps_print_char(mp, d+'0');
+ else mp_ps_print_char(mp, d+'a'-10);
+}
+
+@ We output the marks as a hexadecimal bit string starting at |c| or
+|font_bc[f]|, whichever is greater. If the output has to be truncated
+to avoid exceeding |emergency_line_length| the return value says where to
+start scanning next time.
+
+@<Declarations@>=
+static halfword mp_ps_marks_out (MP mp,font_number f, eight_bits c);
+
+@
+@d emergency_line_length 255
+ /* \ps\ output lines can be this long in unusual circumstances */
+
+@c
+static halfword mp_ps_marks_out (MP mp,font_number f, eight_bits c) {
+ eight_bits bc,ec; /* only encode characters between these bounds */
+ integer lim; /* the maximum number of marks to encode before truncating */
+ int p; /* |font_info| index for the current character */
+ int d; /* used to construct a hexadecimal digit */
+ unsigned b; /* used to construct a hexadecimal digit */
+ lim=4*(emergency_line_length-mp->ps->ps_offset-4);
+ bc=mp->font_bc[f];
+ ec=mp->font_ec[f];
+ if ( c>bc ) bc=c;
+ @<Restrict the range |bc..ec| so that it contains no unused characters
+ at either end and has length at most |lim|@>;
+ @<Print the initial label indicating that the bitmap starts at |bc|@>;
+ @<Print a hexadecimal encoding of the marks for characters |bc..ec|@>;
+ while ( (ec<mp->font_ec[f])&&(mp->font_info[p].qqqq.b3==mp_unused) ) {
+ p++; ec++;
+ }
+ return (ec+1);
+}
+
+@ We could save time by setting the return value before the loop that
+decrements |ec|, but there is no point in being so tricky.
+
+@<Restrict the range |bc..ec| so that it contains no unused characters...@>=
+p=mp->char_base[f]+bc;
+while ( (mp->font_info[p].qqqq.b3==mp_unused)&&(bc<ec) ) {
+ p++; bc++;
+}
+if ( ec>=(eight_bits)(bc+lim)) ec=(eight_bits)(bc+lim-1);
+p=mp->char_base[f]+ec;
+while ( (mp->font_info[p].qqqq.b3==mp_unused)&&(bc<ec) ) {
+ p--; ec--;
+}
+
+@ @<Print the initial label indicating that the bitmap starts at |bc|@>=
+mp_ps_print_char(mp, ' ');
+mp_hex_digit_out(mp, (quarterword)bc / 16);
+mp_hex_digit_out(mp, (quarterword)bc % 16);
+mp_ps_print_char(mp, ':')
+
+@
+
+@<Print a hexadecimal encoding of the marks for characters |bc..ec|@>=
+b=8; d=0;
+for (p=mp->char_base[f]+bc;p<=mp->char_base[f]+ec;p++) {
+ if ( b==0 ) {
+ mp_hex_digit_out(mp, (quarterword)d);
+ d=0; b=8;
+ }
+ if ( mp->font_info[p].qqqq.b3!=mp_unused ) d=d+b;
+ b=b>>1;
+}
+mp_hex_digit_out(mp, (quarterword)d)
+
+
+@ Here is a simple function that determines whether there are any marked
+characters in font~|f| with character code at least~|c|.
+
+@<Declarations@>=
+static boolean mp_check_ps_marks (MP mp,font_number f, integer c) ;
+
+@ @c
+static boolean mp_check_ps_marks (MP mp,font_number f, integer c) {
+ int p; /* |font_info| index for the current character */
+ for (p=mp->char_base[f]+c;p<=mp->char_base[f]+mp->font_ec[f];p++) {
+ if ( mp->font_info[p].qqqq.b3==mp_used )
+ return true;
+ }
+ return false;
+}
+
+
+@ If the file name is so long that it can't be printed without exceeding
+|emergency_line_length| then there will be missing items in the \.{\%*Font:}
+line. We might have to repeat line in order to get the character usage
+information to fit within |emergency_line_length|.
+
+TODO: these two defines are also defined in mp.w!
+
+@d link(A) mp->mem[(A)].hh.rh /* the |link| field of a memory word */
+@d sc_factor(A) mp->mem[(A)+1].cint /* the scale factor stored in a font size node */
+
+@<Print the \.{\%*Font} comment for font |f| and advance |cur_fsize[f]|@>=
+{ integer t=0;
+ while ( mp_check_ps_marks(mp, f,t) ) {
+ mp_ps_print_nl(mp, "%*Font: ");
+ if ( mp->ps->ps_offset+strlen(mp->font_name[f])+12>emergency_line_length )
+ break;
+ mp_ps_print(mp, mp->font_name[f]);
+ mp_ps_print_char(mp, ' ');
+ ds=(mp->font_dsize[f] + 8) / 16;
+ mp_ps_print_scaled(mp, mp_take_scaled(mp, ds,sc_factor(cur_fsize[f])));
+ if ( mp->ps->ps_offset+12>emergency_line_length ) break;
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, ds);
+ if ( mp->ps->ps_offset+5>emergency_line_length ) break;
+ t=mp_ps_marks_out(mp, f, (eight_bits)t);
+ }
+ cur_fsize[f]=link(cur_fsize[f]);
+}
+
+@ @<Print the procset@>=
+{
+ mp_ps_print_nl(mp, "/hlw{0 dtransform exch truncate exch idtransform pop setlinewidth}bd");
+ mp_ps_print_nl(mp, "/vlw{0 exch dtransform truncate idtransform setlinewidth pop}bd");
+ mp_ps_print_nl(mp, "/l{lineto}bd/r{rlineto}bd/c{curveto}bd/m{moveto}bd"
+ "/p{closepath}bd/n{newpath}bd");
+ mp_ps_print_nl(mp, "/C{setcmykcolor}bd/G{setgray}bd/R{setrgbcolor}bd"
+ "/lj{setlinejoin}bd/ml{setmiterlimit}bd");
+ mp_ps_print_nl(mp, "/lc{setlinecap}bd/S{stroke}bd/F{fill}bd/q{gsave}bd"
+ "/Q{grestore}bd/s{scale}bd/t{concat}bd");
+ mp_ps_print_nl(mp, "/sd{setdash}bd/rd{[] 0 setdash}bd/P{showpage}bd/B{q F Q}bd/W{clip}bd");
+}
+
+
+@ The prologue defines \.{fshow} and corrects for the fact that \.{fshow}
+arguments use |font_name| instead of |font_ps_name|. Downloaded bitmap fonts
+might not have reasonable |font_ps_name| entries, but we just charge ahead
+anyway. The user should not make \&{prologues} positive if this will cause
+trouble.
+@:prologues_}{\&{prologues} primitive@>
+
+@<Declarations@>=
+static void mp_print_prologue (MP mp, mp_edge_object *h, int prologues, int procset);
+
+@ @c
+void mp_print_prologue (MP mp, mp_edge_object *h, int prologues, int procset) {
+ font_number f;
+ font_number ldf ;
+ ldf = mp_print_font_comments (mp, h, prologues);
+ mp_ps_print_ln(mp);
+ if ( (prologues==1) && (mp->last_ps_fnum<mp->last_fnum) )
+ mp_read_psname_table(mp);
+ mp_ps_print(mp, "%%BeginProlog"); mp_ps_print_ln(mp);
+ if ( (prologues>0)||(procset>0) ) {
+ if ( ldf!=null_font ) {
+ if ( prologues>0 ) {
+ for (f=null_font+1;f<=mp->last_fnum;f++) {
+ if ( mp_has_font_size(mp,f) ) {
+ mp_ps_name_out(mp, mp->font_name[f],true);
+ mp_ps_name_out(mp, mp->font_ps_name[f],true);
+ mp_ps_print(mp, " def");
+ mp_ps_print_ln(mp);
+ }
+ }
+ if ( procset==0 ) {
+ mp_ps_print(mp, "/fshow {exch findfont exch scalefont setfont show}bind def");
+ mp_ps_print_ln(mp);
+ }
+ }
+ }
+ if (procset>0 ) {
+ mp_ps_print_nl(mp, "%%BeginResource: procset mpost");
+ if ( (prologues>0)&&(ldf!=null_font) )
+ mp_ps_print_nl(mp,
+ "/bd{bind def}bind def/fshow {exch findfont exch scalefont setfont show}bd");
+ else
+ mp_ps_print_nl(mp, "/bd{bind def}bind def");
+ @<Print the procset@>;
+ mp_ps_print_nl(mp, "%%EndResource");
+ mp_ps_print_ln(mp);
+ }
+ }
+ mp_ps_print(mp, "%%EndProlog");
+ mp_ps_print_nl(mp, "%%Page: 1 1"); mp_ps_print_ln(mp);
+}
+
+@ \MP\ used to have one single routine to print to both `write' files
+and the PostScript output. Web2c redefines ``Character |k| cannot be
+printed'', and that resulted in some bugs where 8-bit characters were
+written to the PostScript file (reported by Wlodek Bzyl).
+
+Also, Hans Hagen requested spaces to be output as "\\040" instead of
+a plain space, since that makes it easier to parse the result file
+for postprocessing.
+
+@<Character |k| is not allowed in PostScript output@>=
+ (k<=' ')||(k>'~')
+
+@ We often need to print a pair of coordinates.
+
+@c
+void mp_ps_pair_out (MP mp,scaled x, scaled y) {
+ ps_room(26);
+ mp_ps_print_scaled(mp, x); mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, y); mp_ps_print_char(mp, ' ');
+}
+
+@ @<Declarations@>=
+static void mp_ps_pair_out (MP mp,scaled x, scaled y) ;
+
+@ @c
+void mp_ps_print_cmd (MP mp, const char *l, const char *s) {
+ if ( mp->internal[mp_procset]>0 ) { ps_room(strlen(s)); mp_ps_print(mp,s); }
+ else { ps_room(strlen(l)); mp_ps_print(mp, l); };
+}
+
+@ @<Declarations@>=
+static void mp_ps_print_cmd (MP mp, const char *l, const char *s) ;
+
+@ @c
+void mp_ps_string_out (MP mp, const char *s, size_t l) {
+ ASCII_code k; /* bits to be converted to octal */
+ mp_ps_print(mp, "(");
+ while (l-->0) {
+ k=(ASCII_code)*s++;
+ if ( mp->ps->ps_offset+5>mp->max_print_line ) {
+ mp_ps_print_char(mp, '\\');
+ mp_ps_print_ln(mp);
+ }
+ if ( (@<Character |k| is not allowed in PostScript output@>) ) {
+ mp_ps_print_char(mp, '\\');
+ mp_ps_print_char(mp, '0'+(k / 64));
+ mp_ps_print_char(mp, '0'+((k / 8) % 8));
+ mp_ps_print_char(mp, '0'+(k % 8));
+ } else {
+ if ( (k=='(')||(k==')')||(k=='\\') )
+ mp_ps_print_char(mp, '\\');
+ mp_ps_print_char(mp, k);
+ }
+ }
+ mp_ps_print_char(mp, ')');
+}
+
+@ @<Declarations@>=
+static void mp_ps_string_out (MP mp, const char *s, size_t l) ;
+
+@ This is a define because the function does not use its |mp| argument.
+
+@d mp_is_ps_name(M,A) mp_do_is_ps_name(A)
+
+@c
+static boolean mp_do_is_ps_name (char *s) {
+ ASCII_code k; /* the character being checked */
+ while ((k=(ASCII_code)*s++)) {
+ if ( (k<=' ')||(k>'~') ) return false;
+ if ( (k=='(')||(k==')')||(k=='<')||(k=='>')||
+ (k=='{')||(k=='}')||(k=='/')||(k=='%') ) return false;
+ }
+ return true;
+}
+
+@ @<Declarations@>=
+static void mp_ps_name_out (MP mp, char *s, boolean lit) ;
+
+@ @c
+void mp_ps_name_out (MP mp, char *s, boolean lit) {
+ ps_room(strlen(s)+2);
+ mp_ps_print_char(mp, ' ');
+ if ( mp_is_ps_name(mp, s) ) {
+ if ( lit ) mp_ps_print_char(mp, '/');
+ mp_ps_print(mp, s);
+ } else {
+ mp_ps_string_out(mp, s, strlen(s));
+ if ( ! lit ) mp_ps_print(mp, "cvx ");
+ mp_ps_print(mp, "cvn");
+ }
+}
+
+
+@ These special comments described in the {\sl PostScript Language Reference
+Manual}, 2nd.~edition are understood by some \ps-reading programs.
+We can't normally output ``conforming'' \ps\ because
+the structuring conventions don't allow us to say ``Please make sure the
+following characters are downloaded and define the \.{fshow} macro to access
+them.''
+
+The exact bounding box is written out if |mp_prologues<0|, although this
+is not standard \ps, since it allows \TeX\ to calculate the box dimensions
+accurately. (Overfull boxes are avoided if an illustration is made to
+match a given \.{\char`\\hsize}.)
+
+@<Declarations@>=
+static void mp_print_initial_comment(MP mp,mp_edge_object *hh, int prologues);
+
+@ @c
+void mp_print_initial_comment(MP mp,mp_edge_object *hh, int prologues) {
+ scaled t;
+ char *s;
+ mp_ps_print(mp, "%!PS");
+ if ( prologues>0 )
+ mp_ps_print(mp, "-Adobe-3.0 EPSF-3.0");
+ mp_ps_print_nl(mp, "%%BoundingBox: ");
+ if ( hh->minx>hh->maxx) {
+ mp_ps_print(mp, "0 0 0 0");
+ } else if ( prologues<0 ) {
+ mp_ps_pair_out(mp, hh->minx,hh->miny);
+ mp_ps_pair_out(mp, hh->maxx,hh->maxy);
+ } else {
+ mp_ps_pair_out(mp, mp_floor_scaled(mp, hh->minx),mp_floor_scaled(mp, hh->miny));
+ mp_ps_pair_out(mp, -mp_floor_scaled(mp, -hh->maxx),-mp_floor_scaled(mp, -hh->maxy));
+ }
+ mp_ps_print_nl(mp, "%%HiResBoundingBox: ");
+ if ( hh->minx>hh->maxx ) {
+ mp_ps_print(mp, "0 0 0 0");
+ } else {
+ mp_ps_pair_out(mp, hh->minx,hh->miny);
+ mp_ps_pair_out(mp, hh->maxx,hh->maxy);
+ }
+ mp_ps_print_nl(mp, "%%Creator: MetaPost ");
+ s = mp_metapost_version();
+ mp_ps_print(mp, s);
+ mp_xfree(s);
+ mp_ps_print_nl(mp, "%%CreationDate: ");
+ mp_ps_print_int(mp, mp_round_unscaled(mp, mp->internal[mp_year]));
+ mp_ps_print_char(mp, '.');
+ mp_ps_print_dd(mp, mp_round_unscaled(mp, mp->internal[mp_month]));
+ mp_ps_print_char(mp, '.');
+ mp_ps_print_dd(mp, mp_round_unscaled(mp, mp->internal[mp_day]));
+ mp_ps_print_char(mp, ':');
+ t=mp_round_unscaled(mp, mp->internal[mp_time]);
+ mp_ps_print_dd(mp, t / 60);
+ mp_ps_print_dd(mp, t % 60);
+ mp_ps_print_nl(mp, "%%Pages: 1");
+}
+
+@ The most important output procedure is the one that gives the \ps\ version of
+a \MP\ path.
+
+@(mplibps.h@>=
+typedef struct mp_knot {
+ unsigned short left_type;
+ unsigned short right_type;
+ signed int x_coord;
+ signed int y_coord;
+ signed int left_x;
+ signed int left_y;
+ signed int right_x;
+ signed int right_y;
+ struct mp_knot * next;
+ unsigned char originator;
+} mp_knot;
+
+@ @<Types...@>=
+#define gr_left_type(A) (A)->left_type
+#define gr_right_type(A) (A)->right_type
+#define gr_x_coord(A) (A)->x_coord
+#define gr_y_coord(A) (A)->y_coord
+#define gr_left_x(A) (A)->left_x
+#define gr_left_y(A) (A)->left_y
+#define gr_right_x(A) (A)->right_x
+#define gr_right_y(A) (A)->right_y
+#define gr_next_knot(A) (A)->next
+#define gr_originator(A) (A)->originator
+
+@ If we want to duplicate a knot node, we can say |copy_knot|:
+
+@c
+static mp_knot *mp_gr_copy_knot (MP mp, mp_knot *p) {
+ mp_knot *q; /* the copy */
+ q = mp_xmalloc(mp, 1, sizeof (mp_knot));
+ memcpy(q,p,sizeof (mp_knot));
+ gr_next_knot(q)=NULL;
+ return q;
+}
+
+@ The |copy_path| routine makes a clone of a given path.
+
+@c
+static mp_knot *mp_gr_copy_path (MP mp, mp_knot *p) {
+ mp_knot *q, *pp, *qq; /* for list manipulation */
+ if (p==NULL)
+ return NULL;
+ q=mp_gr_copy_knot(mp, p);
+ qq=q;
+ pp=gr_next_knot(p);
+ while ( pp!=p ) {
+ gr_next_knot(qq)=mp_gr_copy_knot(mp, pp);
+ qq=gr_next_knot(qq);
+ pp=gr_next_knot(pp);
+ }
+ gr_next_knot(qq)=q;
+ return q;
+}
+
+@ Similarly, there's a way to copy the {\sl reverse\/} of a path. This procedure
+returns a pointer to the first node of the copy, if the path is a cycle,
+but to the final node of a non-cyclic copy. The global
+variable |path_tail| will point to the final node of the original path;
+this trick makes it easier to implement `\&{doublepath}'.
+
+All node types are assumed to be |endpoint| or |explicit| only.
+
+This function is currenly unused.
+
+@c
+mp_knot * mp_gr_htap_ypoc (MP mp, mp_knot *p) {
+ mp_knot *q, *pp, *qq, *rr; /* for list manipulation */
+ q=mp_xmalloc(mp, 1, sizeof (mp_knot)); /* this will correspond to |p| */
+ qq=q; pp=p;
+ while (1) {
+ gr_right_type(qq)=gr_left_type(pp);
+ gr_left_type(qq)=gr_right_type(pp);
+ gr_x_coord(qq)=gr_x_coord(pp);
+ gr_y_coord(qq)=gr_y_coord(pp);
+ gr_right_x(qq)=gr_left_x(pp);
+ gr_right_y(qq)=gr_left_y(pp);
+ gr_left_x(qq)=gr_right_x(pp);
+ gr_left_y(qq)=gr_right_y(pp);
+ gr_originator(qq)=gr_originator(pp);
+ if ( gr_next_knot(pp)==p ) {
+ gr_next_knot(q)=qq;
+ /* |mp->path_tail=pp;| */ /* ? */
+ return q;
+ }
+ rr=mp_xmalloc(mp, 1, sizeof (mp_knot));
+ gr_next_knot(rr)=qq;
+ qq=rr;
+ pp=gr_next_knot(pp);
+ }
+}
+
+@ When a cyclic list of knot nodes is no longer needed, it can be recycled by
+calling the following subroutine.
+
+@<Declarations@>=
+static void mp_do_gr_toss_knot_list (mp_knot *p) ;
+
+@
+@d mp_gr_toss_knot_list(B,A) mp_do_gr_toss_knot_list(A)
+
+@c
+void mp_do_gr_toss_knot_list (mp_knot * p) {
+ mp_knot *q; /* the node being freed */
+ mp_knot *r; /* the next node */
+ if (p==NULL)
+ return;
+ q=p;
+ do {
+ r=gr_next_knot(q);
+ mp_xfree(q); q=r;
+ } while (q!=p);
+}
+
+
+
+@ @c
+static void mp_gr_ps_path_out (MP mp, mp_knot *h) {
+ mp_knot *p, *q; /* for scanning the path */
+ scaled d; /* a temporary value */
+ boolean curved; /* |true| unless the cubic is almost straight */
+ ps_room(40);
+ mp_ps_print_cmd(mp, "newpath ","n ");
+ mp_ps_pair_out(mp, gr_x_coord(h),gr_y_coord(h));
+ mp_ps_print_cmd(mp, "moveto","m");
+ p=h;
+ do {
+ if ( gr_right_type(p)==mp_endpoint ) {
+ if ( p==h ) mp_ps_print_cmd(mp, " 0 0 rlineto"," 0 0 r");
+ return;
+ }
+ q=gr_next_knot(p);
+ @<Start a new line and print the \ps\ commands for the curve from
+ |p| to~|q|@>;
+ p=q;
+ } while (p!=h);
+ mp_ps_print_cmd(mp, " closepath"," p");
+}
+
+@ @<Start a new line and print the \ps\ commands for the curve from...@>=
+curved=true;
+@<Set |curved:=false| if the cubic from |p| to |q| is almost straight@>;
+mp_ps_print_ln(mp);
+if ( curved ){
+ mp_ps_pair_out(mp, gr_right_x(p),gr_right_y(p));
+ mp_ps_pair_out(mp, gr_left_x(q),gr_left_y(q));
+ mp_ps_pair_out(mp, gr_x_coord(q),gr_y_coord(q));
+ mp_ps_print_cmd(mp, "curveto","c");
+} else if ( q!=h ){
+ mp_ps_pair_out(mp, gr_x_coord(q),gr_y_coord(q));
+ mp_ps_print_cmd(mp, "lineto","l");
+}
+
+@ Two types of straight lines come up often in \MP\ paths:
+cubics with zero initial and final velocity as created by |make_path| or
+|make_envelope|, and cubics with control points uniformly spaced on a line
+as created by |make_choices|.
+
+@d bend_tolerance 131 /* allow rounding error of $2\cdot10^{-3}$ */
+
+@<Set |curved:=false| if the cubic from |p| to |q| is almost straight@>=
+if ( gr_right_x(p)==gr_x_coord(p) )
+ if ( gr_right_y(p)==gr_y_coord(p) )
+ if ( gr_left_x(q)==gr_x_coord(q) )
+ if ( gr_left_y(q)==gr_y_coord(q) ) curved=false;
+d=gr_left_x(q)-gr_right_x(p);
+if ( abs(gr_right_x(p)-gr_x_coord(p)-d)<=bend_tolerance )
+ if ( abs(gr_x_coord(q)-gr_left_x(q)-d)<=bend_tolerance )
+ { d=gr_left_y(q)-gr_right_y(p);
+ if ( abs(gr_right_y(p)-gr_y_coord(p)-d)<=bend_tolerance )
+ if ( abs(gr_y_coord(q)-gr_left_y(q)-d)<=bend_tolerance ) curved=false;
+ }
+
+@ The colored objects use a struct with anonymous fields to express the color parts:
+
+@(mplibps.h@>=
+typedef struct {
+ int a_val, b_val, c_val, d_val;
+} mp_color;
+
+@ The exported form of a dash pattern is simpler than the internal
+format, it is closely modelled to the PostScript model. The array of
+dashes is ended by a single negative value, because this is not
+allowed in PostScript.
+
+@(mplibps.h@>=
+typedef struct {
+ int offset;
+ int *array;
+} mp_dash_object ;
+
+
+@
+@d mp_gr_toss_dashes(A,B) mp_do_gr_toss_dashes(B)
+
+@<Declarations@>=
+static void mp_do_gr_toss_dashes(mp_dash_object *dl);
+
+@ @c
+void mp_do_gr_toss_dashes(mp_dash_object *dl) {
+ if (dl==NULL)
+ return;
+ mp_xfree(dl->array);
+ mp_xfree(dl);
+}
+
+
+@ @c
+static mp_dash_object *mp_gr_copy_dashes(MP mp, mp_dash_object *dl) {
+ mp_dash_object *q = NULL;
+ (void)mp;
+ if (dl==NULL)
+ return NULL;
+ q = mp_xmalloc(mp, 1, sizeof (mp_dash_object));
+ memcpy (q,dl,sizeof(mp_dash_object));
+ if (dl->array != NULL) {
+ size_t i = 0;
+ while (*(dl->array+i) != -1) i++;
+ q->array = mp_xmalloc(mp, i, sizeof (scaled));
+ memcpy(q->array,dl->array, (i*sizeof(scaled)));
+ }
+ return q;
+}
+
+
+@ Now for outputting the actual graphic objects. First, set up some
+structures and access macros.
+
+@d gr_has_color(A) (gr_type((A))<mp_start_clip_code)
+
+@<Types...@>=
+#define gr_type(A) (A)->type
+#define gr_link(A) (A)->next
+#define gr_color_model(A) (A)->color_model
+#define gr_red_val(A) (A)->color.a_val
+#define gr_green_val(A) (A)->color.b_val
+#define gr_blue_val(A) (A)->color.c_val
+#define gr_cyan_val(A) (A)->color.a_val
+#define gr_magenta_val(A) (A)->color.b_val
+#define gr_yellow_val(A) (A)->color.c_val
+#define gr_black_val(A) (A)->color.d_val
+#define gr_grey_val(A) (A)->color.a_val
+#define gr_path_p(A) (A)->path_p
+#define gr_htap_p(A) ((mp_fill_object *)A)->htap_p
+#define gr_pen_p(A) (A)->pen_p
+#define gr_ljoin_val(A) (A)->ljoin
+#define gr_lcap_val(A) ((mp_stroked_object *)A)->lcap
+#define gr_miterlim_val(A) (A)->miterlim
+#define gr_pre_script(A) (A)->pre_script
+#define gr_post_script(A) (A)->post_script
+#define gr_dash_p(A) ((mp_stroked_object *)A)->dash_p
+#define gr_size_index(A) ((mp_text_object *)A)->size_index
+#define gr_text_p(A) ((mp_text_object *)A)->text_p
+#define gr_text_l(A) ((mp_text_object *)A)->text_l
+#define gr_font_n(A) ((mp_text_object *)A)->font_n
+#define gr_font_name(A) ((mp_text_object *)A)->font_name
+#define gr_font_dsize(A) ((mp_text_object *)A)->font_dsize
+#define gr_width_val(A) ((mp_text_object *)A)->width
+#define gr_height_val(A) ((mp_text_object *)A)->height
+#define gr_depth_val(A) ((mp_text_object *)A)->depth
+#define gr_tx_val(A) ((mp_text_object *)A)->tx
+#define gr_ty_val(A) ((mp_text_object *)A)->ty
+#define gr_txx_val(A) ((mp_text_object *)A)->txx
+#define gr_txy_val(A) ((mp_text_object *)A)->txy
+#define gr_tyx_val(A) ((mp_text_object *)A)->tyx
+#define gr_tyy_val(A) ((mp_text_object *)A)->tyy
+
+@ @(mplibps.h@>=
+#define GRAPHIC_BODY \
+ int type; \
+ struct mp_graphic_object * next
+
+typedef struct mp_graphic_object {
+ GRAPHIC_BODY;
+} mp_graphic_object;
+
+typedef struct mp_text_object {
+ GRAPHIC_BODY;
+ char *pre_script;
+ char *post_script;
+ mp_color color;
+ unsigned char color_model;
+ unsigned char size_index;
+ char *text_p;
+ size_t text_l;
+ char *font_name ;
+ unsigned int font_dsize ;
+ unsigned int font_n ;
+ int width ;
+ int height ;
+ int depth ;
+ int tx ;
+ int ty ;
+ int txx ;
+ int txy ;
+ int tyx ;
+ int tyy ;
+} mp_text_object;
+
+typedef struct mp_fill_object {
+ GRAPHIC_BODY;
+ char *pre_script;
+ char *post_script;
+ mp_color color;
+ unsigned char color_model;
+ unsigned char ljoin ;
+ mp_knot * path_p;
+ mp_knot * htap_p;
+ mp_knot * pen_p;
+ int miterlim ;
+} mp_fill_object;
+
+typedef struct mp_stroked_object {
+ GRAPHIC_BODY;
+ char *pre_script;
+ char *post_script;
+ mp_color color;
+ unsigned char color_model;
+ unsigned char ljoin ;
+ unsigned char lcap ;
+ mp_knot * path_p;
+ mp_knot * pen_p;
+ int miterlim ;
+ mp_dash_object *dash_p;
+} mp_stroked_object;
+
+typedef struct mp_clip_object {
+ GRAPHIC_BODY;
+ mp_knot * path_p;
+} mp_clip_object;
+
+typedef struct mp_bounds_object {
+ GRAPHIC_BODY;
+ mp_knot * path_p;
+} mp_bounds_object;
+
+typedef struct mp_special_object {
+ GRAPHIC_BODY;
+ char *pre_script;
+} mp_special_object ;
+
+typedef struct mp_edge_object {
+ struct mp_graphic_object * body;
+ struct mp_edge_object * next;
+ char * filename;
+ MP parent;
+ int minx, miny, maxx, maxy;
+ int width, height, depth, ital_corr;
+ int charcode;
+} mp_edge_object;
+
+@ @<Exported function headers@>=
+mp_graphic_object *mp_new_graphic_object(MP mp, int type);
+
+@ @c
+mp_graphic_object *mp_new_graphic_object (MP mp, int type) {
+ mp_graphic_object *p;
+ size_t size ;
+ switch (type) {
+ case mp_fill_code: size = sizeof(mp_fill_object); break;
+ case mp_stroked_code: size = sizeof(mp_stroked_object); break;
+ case mp_text_code: size = sizeof(mp_text_object); break;
+ case mp_start_clip_code: size = sizeof(mp_clip_object); break;
+ case mp_start_bounds_code: size = sizeof(mp_bounds_object); break;
+ case mp_special_code: size = sizeof(mp_special_object); break;
+ default: size = sizeof(mp_graphic_object); break;
+ }
+ p = (mp_graphic_object *)mp_xmalloc(mp,1,size);
+ memset(p,0,size);
+ gr_type(p) = type;
+ return p;
+}
+
+@ We need to keep track of several parameters from the \ps\ graphics state.
+@^graphics state@>
+This allows us to be sure that \ps\ has the correct values when they are
+needed without wasting time and space setting them unnecessarily.
+
+@d gs_red mp->ps->gs_state->red_field
+@d gs_green mp->ps->gs_state->green_field
+@d gs_blue mp->ps->gs_state->blue_field
+@d gs_black mp->ps->gs_state->black_field
+@d gs_colormodel mp->ps->gs_state->colormodel_field
+@d gs_ljoin mp->ps->gs_state->ljoin_field
+@d gs_lcap mp->ps->gs_state->lcap_field
+@d gs_adj_wx mp->ps->gs_state->adj_wx_field
+@d gs_miterlim mp->ps->gs_state->miterlim_field
+@d gs_dash_p mp->ps->gs_state->dash_p_field
+@d gs_dash_init_done mp->ps->gs_state->dash_done_field
+@d gs_previous mp->ps->gs_state->previous_field
+@d gs_width mp->ps->gs_state->width_field
+
+@<Types...@>=
+typedef struct _gs_state {
+ scaled red_field ;
+ scaled green_field ;
+ scaled blue_field ;
+ scaled black_field ;
+ /* color from the last \&{setcmykcolor} or \&{setrgbcolor} or \&{setgray} command */
+ quarterword colormodel_field ;
+ /* the current colormodel */
+ quarterword ljoin_field ;
+ quarterword lcap_field ;
+ /* values from the last \&{setlinejoin} and \&{setlinecap} commands */
+ quarterword adj_wx_field ;
+ /* what resolution-dependent adjustment applies to the width */
+ scaled miterlim_field ;
+ /* the value from the last \&{setmiterlimit} command */
+ mp_dash_object * dash_p_field ;
+ /* edge structure for last \&{setdash} command */
+ boolean dash_done_field ; /* to test for initial \&{setdash} */
+ struct _gs_state * previous_field ;
+ /* backlink to the previous |_gs_state| structure */
+ scaled width_field ;
+ /* width setting or $-1$ if no \&{setlinewidth} command so far */
+} _gs_state;
+
+
+@ @<Glob...@>=
+struct _gs_state * gs_state;
+
+@ @<Set init...@>=
+mp->ps->gs_state=NULL;
+
+@ @<Dealloc variables@>=
+mp_xfree(mp->ps->gs_state);
+
+@ To avoid making undue assumptions about the initial graphics state, these
+parameters are given special values that are guaranteed not to match anything
+in the edge structure being shipped out. On the other hand, the initial color
+should be black so that the translation of an all-black picture will have no
+\&{setcolor} commands. (These would be undesirable in a font application.)
+Hence we use |c=0| when initializing the graphics state and we use |c<0|
+to recover from a situation where we have lost track of the graphics state.
+
+@d mp_void (null+1) /* a null pointer different from |null| */
+
+@c static void mp_gs_unknown_graphics_state (MP mp,scaled c) {
+ struct _gs_state *p; /* to shift graphic states around */
+ if ( (c==0)||(c==-1) ) {
+ if ( mp->ps->gs_state==NULL ) {
+ mp->ps->gs_state = mp_xmalloc(mp,1,sizeof(struct _gs_state));
+ gs_previous=NULL;
+ } else {
+ while ( gs_previous!=NULL ) {
+ p = gs_previous;
+ mp_xfree(mp->ps->gs_state);
+ mp->ps->gs_state=p;
+ }
+ }
+ gs_red=c; gs_green=c; gs_blue=c; gs_black=c;
+ gs_colormodel=mp_uninitialized_model;
+ gs_ljoin=3;
+ gs_lcap=3;
+ gs_miterlim=0;
+ gs_dash_p=NULL;
+ gs_dash_init_done=false;
+ gs_width=-1;
+ } else if ( c==1 ) {
+ p= mp->ps->gs_state;
+ mp->ps->gs_state = mp_xmalloc(mp,1,sizeof(struct _gs_state));
+ memcpy(mp->ps->gs_state,p,sizeof(struct _gs_state));
+ gs_previous = p;
+ } else if ( c==2 ) {
+ p = gs_previous;
+ mp_xfree(mp->ps->gs_state);
+ mp->ps->gs_state=p;
+ }
+}
+
+
+@ When it is time to output a graphical object, |fix_graphics_state| ensures
+that \ps's idea of the graphics state agrees with what is stored in the object.
+
+@<Declarations@>=
+static void mp_gr_fix_graphics_state (MP mp, mp_graphic_object *p) ;
+
+@ @c
+void mp_gr_fix_graphics_state (MP mp, mp_graphic_object *p) {
+ /* get ready to output graphical object |p| */
+ mp_knot *pp, *path_p; /* for list manipulation */
+ mp_dash_object *hh;
+ scaled wx,wy,ww; /* dimensions of pen bounding box */
+ quarterword adj_wx; /* whether pixel rounding should be based on |wx| or |wy| */
+ integer tx,ty; /* temporaries for computing |adj_wx| */
+ if ( gr_has_color(p) )
+ @<Make sure \ps\ will use the right color for object~|p|@>;
+ if ( (gr_type(p)==mp_fill_code)||(gr_type(p)==mp_stroked_code) ) {
+ if (gr_type(p)==mp_fill_code) {
+ pp = gr_pen_p((mp_fill_object *)p);
+ path_p = gr_path_p((mp_fill_object *)p);
+ } else {
+ pp = gr_pen_p((mp_stroked_object *)p);
+ path_p = gr_path_p((mp_stroked_object *)p);
+ }
+ if ( pp!=NULL )
+ if ( pen_is_elliptical(pp) ) {
+ @<Generate \ps\ code that sets the stroke width to the
+ appropriate rounded value@>;
+ @<Make sure \ps\ will use the right dash pattern for |dash_p(p)|@>;
+ @<Decide whether the line cap parameter matters and set it if necessary@>;
+ @<Set the other numeric parameters as needed for object~|p|@>;
+ }
+ }
+ if ( mp->ps->ps_offset>0 ) mp_ps_print_ln(mp);
+}
+
+@ @<Decide whether the line cap parameter matters and set it if necessary@>=
+if ( gr_type(p)==mp_stroked_code ) {
+ mp_stroked_object *ts = (mp_stroked_object *)p;
+ if ( (gr_left_type(gr_path_p(ts))==mp_endpoint)||(gr_dash_p(ts)!=NULL) )
+ if ( gs_lcap!=(quarterword)gr_lcap_val(ts) ) {
+ ps_room(13);
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_char(mp, '0'+gr_lcap_val(ts));
+ mp_ps_print_cmd(mp, " setlinecap"," lc");
+ gs_lcap=(quarterword)gr_lcap_val(ts);
+ }
+}
+
+@
+@d set_ljoin_miterlim(p)
+ if ( gs_ljoin!=(quarterword)gr_ljoin_val(p) ) {
+ ps_room(14);
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_char(mp, '0'+gr_ljoin_val(p));
+ mp_ps_print_cmd(mp, " setlinejoin"," lj");
+ gs_ljoin=(quarterword)gr_ljoin_val(p);
+ }
+ if ( gs_miterlim!=gr_miterlim_val(p) ) {
+ ps_room(27);
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, gr_miterlim_val(p));
+ mp_ps_print_cmd(mp, " setmiterlimit"," ml");
+ gs_miterlim=gr_miterlim_val(p);
+ }
+
+@<Set the other numeric parameters as needed for object~|p|@>=
+if ( gr_type(p)==mp_stroked_code ) {
+ mp_stroked_object *ts = (mp_stroked_object *)p;
+ set_ljoin_miterlim(ts);
+} else {
+ mp_fill_object *ts = (mp_fill_object *)p;
+ set_ljoin_miterlim(ts);
+}
+
+@
+@d set_color_objects(pq)
+ object_color_model = pq->color_model;
+ object_color_a = pq->color.a_val;
+ object_color_b = pq->color.b_val;
+ object_color_c = pq->color.c_val;
+ object_color_d = pq->color.d_val;
+
+@<Make sure \ps\ will use the right color for object~|p|@>=
+{
+ int object_color_model;
+ int object_color_a, object_color_b, object_color_c, object_color_d ;
+ if (gr_type(p) == mp_fill_code) {
+ mp_fill_object *pq = (mp_fill_object *)p;
+ set_color_objects(pq);
+ } else if (gr_type(p) == mp_stroked_code) {
+ mp_stroked_object *pq = (mp_stroked_object *)p;
+ set_color_objects(pq);
+ } else {
+ mp_text_object *pq = (mp_text_object *)p;
+ set_color_objects(pq);
+ }
+
+ if ( object_color_model==mp_rgb_model) {
+ if ( (gs_colormodel!=mp_rgb_model)||(gs_red!=object_color_a)||
+ (gs_green!=object_color_b)||(gs_blue!=object_color_c) ) {
+ gs_red = object_color_a;
+ gs_green = object_color_b;
+ gs_blue = object_color_c;
+ gs_black = -1;
+ gs_colormodel=mp_rgb_model;
+ { ps_room(36);
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, gs_red); mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, gs_green); mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, gs_blue);
+ mp_ps_print_cmd(mp, " setrgbcolor", " R");
+ }
+ }
+ } else if ( object_color_model==mp_cmyk_model) {
+ if ( (gs_red!=object_color_a)||(gs_green!=object_color_b)||
+ (gs_blue!=object_color_c)||(gs_black!=object_color_d)||
+ (gs_colormodel!=mp_cmyk_model) ) {
+ gs_red = object_color_a;
+ gs_green = object_color_b;
+ gs_blue = object_color_c;
+ gs_black = object_color_d;
+ gs_colormodel=mp_cmyk_model;
+ { ps_room(45);
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, gs_red);
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, gs_green);
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, gs_blue);
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, gs_black);
+ mp_ps_print_cmd(mp, " setcmykcolor"," C");
+ }
+ }
+ } else if ( object_color_model==mp_grey_model ) {
+ if ( (gs_red!=object_color_a)||(gs_colormodel!=mp_grey_model) ) {
+ gs_red = object_color_a;
+ gs_green = -1;
+ gs_blue = -1;
+ gs_black = -1;
+ gs_colormodel=mp_grey_model;
+ { ps_room(16);
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, gs_red);
+ mp_ps_print_cmd(mp, " setgray"," G");
+ }
+ }
+ } else if ( object_color_model==mp_no_model ) {
+ gs_colormodel=mp_no_model;
+ }
+}
+
+@ In order to get consistent widths for horizontal and vertical pen strokes, we
+want \ps\ to use an integer number of pixels for the \&{setwidth} parameter.
+@:setwidth}{\&{setwidth}command@>
+We set |gs_width| to the ideal horizontal or vertical stroke width and then
+generate \ps\ code that computes the rounded value. For non-circular pens, the
+pen shape will be rescaled so that horizontal or vertical parts of the stroke
+have the computed width.
+
+Rounding the width to whole pixels is not likely to improve the appearance of
+diagonal or curved strokes, but we do it anyway for consistency. The
+\&{truncate} command generated here tends to make all the strokes a little
+@:truncate}{\&{truncate} command@>
+thinner, but this is appropriate for \ps's scan-conversion rules. Even with
+truncation, an ideal with of $w$~pixels gets mapped into $\lfloor w\rfloor+1$.
+It would be better to have $\lceil w\rceil$ but that is ridiculously expensive
+to compute in \ps.
+
+@<Generate \ps\ code that sets the stroke width...@>=
+@<Set |wx| and |wy| to the width and height of the bounding box for
+ |pen_p(p)|@>;
+@<Use |pen_p(p)| and |path_p(p)| to decide whether |wx| or |wy| is more
+ important and set |adj_wx| and |ww| accordingly@>;
+if ( (ww!=gs_width) || (adj_wx!=gs_adj_wx) ) {
+ if ( adj_wx != 0 ) {
+ ps_room(13);
+ mp_ps_print_char(mp, ' '); mp_ps_print_scaled(mp, ww);
+ mp_ps_print_cmd(mp,
+ " 0 dtransform exch truncate exch idtransform pop setlinewidth"," hlw");
+ } else {
+ if ( mp->internal[mp_procset]>0 ) {
+ ps_room(13);
+ mp_ps_print_char(mp, ' ');
+ mp_ps_print_scaled(mp, ww);
+ mp_ps_print(mp, " vlw");
+ } else {
+ ps_room(15);
+ mp_ps_print(mp, " 0 "); mp_ps_print_scaled(mp, ww);
+ mp_ps_print(mp, " dtransform truncate idtransform setlinewidth pop");
+ }
+ }
+ gs_width = ww;
+ gs_adj_wx = adj_wx;
+}
+
+@ @<Set |wx| and |wy| to the width and height of the bounding box for...@>=
+if ( (gr_right_x(pp)==gr_x_coord(pp)) && (gr_left_y(pp)==gr_y_coord(pp)) ) {
+ wx = abs(gr_left_x(pp) - gr_x_coord(pp));
+ wy = abs(gr_right_y(pp) - gr_y_coord(pp));
+} else {
+ wx = mp_pyth_add(mp, gr_left_x(pp)-gr_x_coord(pp), gr_right_x(pp)-gr_x_coord(pp));
+ wy = mp_pyth_add(mp, gr_left_y(pp)-gr_y_coord(pp), gr_right_y(pp)-gr_y_coord(pp));
+}
+
+@ The path is considered ``essentially horizontal'' if its range of
+$y$~coordinates is less than the $y$~range |wy| for the pen. ``Essentially
+vertical'' paths are detected similarly. This code ensures that no component
+of the pen transformation is more that |aspect_bound*(ww+1)|.
+
+@d aspect_bound 10 /* ``less important'' of |wx|, |wy| cannot exceed the other by
+ more than this factor */
+
+@d do_x_loc 1
+@d do_y_loc 2
+
+@<Use |pen_p(p)| and |path_p(p)| to decide whether |wx| or |wy| is more...@>=
+tx=1; ty=1;
+if ( mp_gr_coord_rangeOK(path_p, do_y_loc, wy) ) tx=aspect_bound;
+else if ( mp_gr_coord_rangeOK(path_p, do_x_loc, wx) ) ty=aspect_bound;
+if ( wy / ty>=wx / tx ) { ww=wy; adj_wx=0; }
+else { ww=wx; adj_wx=1; }
+
+@ This routine quickly tests if path |h| is ``essentially horizontal'' or
+``essentially vertical,'' where |zoff| is |x_loc(0)| or |y_loc(0)| and |dz| is
+allowable range for $x$ or~$y$. We do not need and cannot afford a full
+bounding-box computation.
+
+@<Declarations@>=
+static boolean mp_gr_coord_rangeOK (mp_knot *h,
+ quarterword zoff, scaled dz);
+
+@ @c
+boolean mp_gr_coord_rangeOK (mp_knot *h,
+ quarterword zoff, scaled dz) {
+ mp_knot *p; /* for scanning the path form |h| */
+ scaled zlo,zhi; /* coordinate range so far */
+ scaled z; /* coordinate currently being tested */
+ if (zoff==do_x_loc) {
+ zlo=gr_x_coord(h);
+ zhi=zlo;
+ p=h;
+ while ( gr_right_type(p)!=mp_endpoint ) {
+ z=gr_right_x(p);
+ @<Make |zlo..zhi| include |z| and |return false| if |zhi-zlo>dz|@>;
+ p=gr_next_knot(p); z=gr_left_x(p);
+ @<Make |zlo..zhi| include |z| and |return false| if |zhi-zlo>dz|@>;
+ z=gr_x_coord(p);
+ @<Make |zlo..zhi| include |z| and |return false| if |zhi-zlo>dz|@>;
+ if ( p==h ) break;
+ }
+ } else {
+ zlo=gr_y_coord(h);
+ zhi=zlo;
+ p=h;
+ while ( gr_right_type(p)!=mp_endpoint ) {
+ z=gr_right_y(p);
+ @<Make |zlo..zhi| include |z| and |return false| if |zhi-zlo>dz|@>;
+ p=gr_next_knot(p); z=gr_left_y(p);
+ @<Make |zlo..zhi| include |z| and |return false| if |zhi-zlo>dz|@>;
+ z=gr_y_coord(p);
+ @<Make |zlo..zhi| include |z| and |return false| if |zhi-zlo>dz|@>;
+ if ( p==h ) break;
+ }
+ }
+ return true;
+}
+
+@ @<Make |zlo..zhi| include |z| and |return false| if |zhi-zlo>dz|@>=
+if ( z<zlo ) zlo=z;
+else if ( z>zhi ) zhi=z;
+if ( zhi-zlo>dz ) return false
+
+@ Filling with an elliptical pen is implemented via a combination of \&{stroke}
+and \&{fill} commands and a nontrivial dash pattern would interfere with this.
+@:stroke}{\&{stroke} command@>
+@:fill}{\&{fill} command@>
+Note that we don't use |delete_edge_ref| because |gs_dash_p| is not counted as
+a reference.
+
+@<Make sure \ps\ will use the right dash pattern for |dash_p(p)|@>=
+if ( gr_type(p)==mp_fill_code || gr_dash_p(p) == NULL) {
+ hh=NULL;
+} else {
+ hh=gr_dash_p(p);
+}
+if ( hh==NULL ) {
+ if ( gs_dash_p!=NULL || gs_dash_init_done == false) {
+ mp_ps_print_cmd(mp, " [] 0 setdash"," rd");
+ gs_dash_p=NULL;
+ gs_dash_init_done=true;
+ }
+} else if ( ! mp_gr_same_dashes(gs_dash_p,hh) ) {
+ @<Set the dash pattern from |dash_list(hh)| scaled by |scf|@>;
+}
+
+@ The original code had a check here to ensure that the result from
+|mp_take_scaled| did not go out of bounds.
+
+@<Set the dash pattern from |dash_list(hh)| scaled by |scf|@>=
+{ gs_dash_p=hh;
+ if ( (gr_dash_p(p)==NULL) || (hh==NULL) || (hh->array==NULL)) {
+ mp_ps_print_cmd(mp, " [] 0 setdash"," rd");
+ } else {
+ int i;
+ ps_room(28);
+ mp_ps_print(mp, " [");
+ for (i=0; *(hh->array+i) != -1;i++) {
+ ps_room(13);
+ mp_ps_print_scaled(mp, *(hh->array+i));
+ mp_ps_print_char(mp, ' ') ;
+ }
+ ps_room(22);
+ mp_ps_print(mp, "] ");
+ mp_ps_print_scaled(mp, hh->offset);
+ mp_ps_print_cmd(mp, " setdash"," sd");
+ }
+}
+
+@ @<Declarations@>=
+static boolean mp_gr_same_dashes (mp_dash_object *h, mp_dash_object *hh) ;
+
+@ This function test if |h| and |hh| represent the same dash pattern.
+
+@c
+boolean mp_gr_same_dashes (mp_dash_object *h, mp_dash_object *hh) {
+ boolean ret=false;
+ int i = 0;
+ if ( h==hh ) ret=true;
+ else if ( (h==NULL)||(hh==NULL) ) ret=false;
+ else if ( h->offset!=hh->offset ) ret=false;
+ else if ( h->array == hh->array ) ret=true;
+ else if ( h->array == NULL || hh->array == NULL) ret=false;
+ else { @<Compare |dash_list(h)| and |dash_list(hh)|@>; }
+ return ret;
+}
+
+@ @<Compare |dash_list(h)| and |dash_list(hh)|@>=
+{
+ while (*(h->array+i)!=-1 &&
+ *(hh->array+i)!=-1 &&
+ *(h->array+i) == *(hh->array+i)) i++;
+ if (i>0) {
+ if (*(h->array+i)==-1 && *(hh->array+i) == -1)
+ ret=true;
+ }
+}
+
+@ When stroking a path with an elliptical pen, it is necessary to transform
+the coordinate system so that a unit circular pen will have the desired shape.
+To keep this transformation local, we enclose it in a
+$$\&{gsave}\ldots\&{grestore}$$
+block. Any translation component must be applied to the path being stroked
+while the rest of the transformation must apply only to the pen.
+If |fill_also=true|, the path is to be filled as well as stroked so we must
+insert commands to do this after giving the path.
+
+@<Declarations@>=
+static void mp_gr_stroke_ellipse (MP mp, mp_graphic_object *h, boolean fill_also) ;
+
+@
+@c void mp_gr_stroke_ellipse (MP mp, mp_graphic_object *h, boolean fill_also) {
+ /* generate an elliptical pen stroke from object |h| */
+ scaled txx,txy,tyx,tyy; /* transformation parameters */
+ mp_knot *p; /* the pen to stroke with */
+ scaled d1,det; /* for tweaking transformation parameters */
+ integer s; /* also for tweaking transformation paramters */
+ boolean transformed; /* keeps track of whether gsave/grestore are needed */
+ transformed=false;
+ @<Use |pen_p(h)| to set the transformation parameters and give the initial
+ translation@>;
+ @<Tweak the transformation parameters so the transformation is nonsingular@>;
+ if (gr_type(h)==mp_fill_code) {
+ mp_gr_ps_path_out(mp, gr_path_p((mp_fill_object *)h));
+ } else {
+ mp_gr_ps_path_out(mp, gr_path_p((mp_stroked_object *)h));
+ }
+ if ( mp->internal[mp_procset]==0 ) {
+ if ( fill_also ) mp_ps_print_nl(mp, "gsave fill grestore");
+ @<Issue \ps\ commands to transform the coordinate system@>;
+ mp_ps_print(mp, " stroke");
+ if ( transformed ) mp_ps_print(mp, " grestore");
+ } else {
+ if ( fill_also ) mp_ps_print_nl(mp, "B"); else mp_ps_print_ln(mp);
+ if ( (txy!=0)||(tyx!=0) ) {
+ mp_ps_print(mp, " [");
+ mp_ps_pair_out(mp, txx,tyx);
+ mp_ps_pair_out(mp, txy,tyy);
+ mp_ps_print(mp, "0 0] t");
+ } else if ((txx!=unity)||(tyy!=unity) ) {
+ mp_ps_pair_out(mp,txx,tyy);
+ mp_ps_print(mp, " s");
+ };
+ mp_ps_print(mp, " S");
+ if ( transformed ) mp_ps_print(mp, " Q");
+ }
+ mp_ps_print_ln(mp);
+}
+
+@ @<Use |pen_p(h)| to set the transformation parameters and give the...@>=
+if (gr_type(h)==mp_fill_code) {
+ p=gr_pen_p((mp_fill_object *)h);
+} else {
+ p=gr_pen_p((mp_stroked_object *)h);
+}
+txx=gr_left_x(p);
+tyx=gr_left_y(p);
+txy=gr_right_x(p);
+tyy=gr_right_y(p);
+if ( (gr_x_coord(p)!=0)||(gr_y_coord(p)!=0) ) {
+ mp_ps_print_nl(mp, "");
+ mp_ps_print_cmd(mp, "gsave ","q ");
+ mp_ps_pair_out(mp, gr_x_coord(p), gr_y_coord(p));
+ mp_ps_print(mp, "translate ");
+ txx-=gr_x_coord(p);
+ tyx-=gr_y_coord(p);
+ txy-=gr_x_coord(p);
+ tyy-=gr_y_coord(p);
+ transformed=true;
+} else {
+ mp_ps_print_nl(mp, "");
+}
+@<Adjust the transformation to account for |gs_width| and output the
+ initial \&{gsave} if |transformed| should be |true|@>
+
+@ @<Adjust the transformation to account for |gs_width| and output the...@>=
+if ( gs_width!=unity ) {
+ if ( gs_width==0 ) {
+ txx=unity; tyy=unity;
+ } else {
+ txx=mp_make_scaled(mp, txx,gs_width);
+ txy=mp_make_scaled(mp, txy,gs_width);
+ tyx=mp_make_scaled(mp, tyx,gs_width);
+ tyy=mp_make_scaled(mp, tyy,gs_width);
+ };
+}
+if ( (txy!=0)||(tyx!=0)||(txx!=unity)||(tyy!=unity) ) {
+ if ( (! transformed) ){
+ mp_ps_print_cmd(mp, "gsave ","q ");
+ transformed=true;
+ }
+}
+
+@ @<Issue \ps\ commands to transform the coordinate system@>=
+if ( (txy!=0)||(tyx!=0) ){
+ mp_ps_print_ln(mp);
+ mp_ps_print_char(mp, '[');
+ mp_ps_pair_out(mp, txx,tyx);
+ mp_ps_pair_out(mp, txy,tyy);
+ mp_ps_print(mp, "0 0] concat");
+} else if ( (txx!=unity)||(tyy!=unity) ){
+ mp_ps_print_ln(mp);
+ mp_ps_pair_out(mp, txx,tyy);
+ mp_ps_print(mp, "scale");
+}
+
+@ The \ps\ interpreter will probably abort if it encounters a singular
+transformation matrix. The determinant must be large enough to ensure that
+the printed representation will be nonsingular. Since the printed
+representation is always within $2^{-17}$ of the internal |scaled| value, the
+total error is at most $4T_{\rm max}2^{-17}$, where $T_{\rm max}$ is a bound on
+the magnitudes of |txx/65536|, |txy/65536|, etc.
+
+The |aspect_bound*(gs_width+1)| bound on the components of the pen
+transformation allows $T_{\rm max}$ to be at most |2*aspect_bound|.
+
+@<Tweak the transformation parameters so the transformation is nonsingular@>=
+det=mp_take_scaled(mp, txx,tyy) - mp_take_scaled(mp, txy,tyx);
+d1=4*aspect_bound+1;
+if ( abs(det)<d1 ) {
+ if ( det>=0 ) { d1=d1-det; s=1; }
+ else { d1=-d1-det; s=-1; };
+ d1=d1*unity;
+ if ( abs(txx)+abs(tyy)>=abs(txy)+abs(tyy) ) {
+ if ( abs(txx)>abs(tyy) ) tyy=tyy+(d1+s*abs(txx)) / txx;
+ else txx=txx+(d1+s*abs(tyy)) / tyy;
+ } else {
+ if ( abs(txy)>abs(tyx) ) tyx=tyx+(d1+s*abs(txy)) / txy;
+ else txy=txy+(d1+s*abs(tyx)) / tyx;
+ }
+}
+
+@ Here is a simple routine that just fills a cycle.
+
+@<Declarations@>=
+static void mp_gr_ps_fill_out (MP mp, mp_knot *p);
+
+@ @c
+void mp_gr_ps_fill_out (MP mp, mp_knot *p) { /* fill cyclic path~|p| */
+ mp_gr_ps_path_out(mp, p);
+ mp_ps_print_cmd(mp, " fill"," F");
+ mp_ps_print_ln(mp);
+}
+
+@ A text node may specify an arbitrary transformation but the usual case
+involves only shifting, scaling, and occasionally rotation. The purpose
+of |choose_scale| is to select a scale factor so that the remaining
+transformation is as ``nice'' as possible. The definition of ``nice''
+is somewhat arbitrary but shifting and $90^\circ$ rotation are especially
+nice because they work out well for bitmap fonts. The code here selects
+a scale factor equal to $1/\sqrt2$ times the Frobenius norm of the
+non-shifting part of the transformation matrix. It is careful to avoid
+additions that might cause undetected overflow.
+
+@<Declarations@>=
+static scaled mp_gr_choose_scale (MP mp, mp_graphic_object *p) ;
+
+@ @c scaled mp_gr_choose_scale (MP mp, mp_graphic_object *p) {
+ /* |p| should point to a text node */
+ scaled a,b,c,d,ad,bc; /* temporary values */
+ a=gr_txx_val(p);
+ b=gr_txy_val(p);
+ c=gr_tyx_val(p);
+ d=gr_tyy_val(p);
+ if ( a<0 ) negate(a);
+ if ( b<0 ) negate(b);
+ if ( c<0 ) negate(c);
+ if ( d<0 ) negate(d);
+ ad=half(a-d);
+ bc=half(b-c);
+ return mp_pyth_add(mp, mp_pyth_add(mp, d+ad,ad), mp_pyth_add(mp, c+bc,bc));
+}
+
+@ The potential overflow here is caused by the fact the returned value
+has to fit in a |name_type|, which is a quarterword.
+
+@d fscale_tolerance 65 /* that's $.001\times2^{16}$ */
+
+@<Declarations@>=
+static quarterword mp_size_index (MP mp, font_number f, scaled s) ;
+
+@ @c
+quarterword mp_size_index (MP mp, font_number f, scaled s) {
+ pointer p,q; /* the previous and current font size nodes */
+ quarterword i; /* the size index for |q| */
+ q=mp->font_sizes[f];
+ i=0;
+ while ( q!=null ) {
+ if ( abs(s-sc_factor(q))<=fscale_tolerance )
+ return i;
+ else
+ { p=q; q=link(q); incr(i); };
+ if ( i==max_quarterword )
+ mp_overflow(mp, "sizes per font",max_quarterword);
+@:MetaPost capacity exceeded sizes per font}{\quad sizes per font@>
+ }
+ q=mp_get_node(mp, font_size_size);
+ sc_factor(q)=s;
+ if ( i==0 ) mp->font_sizes[f]=q; else link(p)=q;
+ return i;
+}
+
+@ @<Declarations@>=
+static scaled mp_indexed_size (MP mp,font_number f, quarterword j);
+
+@ @c
+scaled mp_indexed_size (MP mp,font_number f, quarterword j) {
+ pointer p; /* a font size node */
+ quarterword i; /* the size index for |p| */
+ p=mp->font_sizes[f];
+ i=0;
+ if ( p==null ) mp_confusion(mp, "size");
+ while ( (i!=j) ) {
+ incr(i); p=link(p);
+ if ( p==null ) mp_confusion(mp, "size");
+ }
+ return sc_factor(p);
+}
+
+@ @<Declarations@>=
+static void mp_clear_sizes (MP mp) ;
+
+@ @c void mp_clear_sizes (MP mp) {
+ font_number f; /* the font whose size list is being cleared */
+ pointer p; /* current font size nodes */
+ for (f=null_font+1;f<=mp->last_fnum;f++) {
+ while ( mp->font_sizes[f]!=null ) {
+ p=mp->font_sizes[f];
+ mp->font_sizes[f]=link(p);
+ mp_free_node(mp, p,font_size_size);
+ }
+ }
+}
+
+@ A text node may specify an arbitrary transformation but the usual case
+involves only shifting, scaling, and occasionally rotation. The purpose
+of |choose_scale| is to select a scale factor so that the remaining
+transformation is as ``nice'' as possible. The definition of ``nice''
+is somewhat arbitrary but shifting and $90^\circ$ rotation are especially
+nice because they work out well for bitmap fonts. The code here selects
+a scale factor equal to $1/\sqrt2$ times the Frobenius norm of the
+non-shifting part of the transformation matrix. It is careful to avoid
+additions that might cause undetected overflow.
+
+
+@ @c static scaled mp_choose_scale (MP mp, mp_graphic_object *p) {
+ /* |p| should point to a text node */
+ scaled a,b,c,d,ad,bc; /* temporary values */
+ a=gr_txx_val(p);
+ b=gr_txy_val(p);
+ c=gr_tyx_val(p);
+ d=gr_tyy_val(p);
+ if ( (a<0) ) negate(a);
+ if ( (b<0) ) negate(b);
+ if ( (c<0) ) negate(c);
+ if ( (d<0) ) negate(d);
+ ad=half(a-d);
+ bc=half(b-c);
+ return mp_pyth_add(mp, mp_pyth_add(mp, d+ad,ad), mp_pyth_add(mp, c+bc,bc));
+}
+
+@ There may be many sizes of one font and we need to keep track of the
+characters used for each size. This is done by keeping a linked list of
+sizes for each font with a counter in each text node giving the appropriate
+position in the size list for its font.
+
+@d font_size_size 2 /* size of a font size node */
+
+
+@ @<Declarations@>=
+static void mp_apply_mark_string_chars(MP mp, mp_edge_object *h, int next_size);
+
+@ @c
+void mp_apply_mark_string_chars(MP mp, mp_edge_object *h, int next_size) {
+ mp_graphic_object * p;
+ p=h->body;
+ while ( p!= NULL ) {
+ if ( gr_type(p)==mp_text_code ) {
+ if ( gr_font_n(p)!=null_font ) {
+ if ( gr_size_index(p)==(unsigned char)next_size )
+ mp_mark_string_chars(mp, gr_font_n(p),gr_text_p(p),gr_text_l(p));
+ }
+ }
+ p=gr_link(p);
+ }
+}
+
+@ @<Unmark all marked characters@>=
+for (f=null_font+1;f<=mp->last_fnum;f++) {
+ if ( mp->font_sizes[f]!=null ) {
+ mp_unmark_font(mp, f);
+ mp->font_sizes[f]=null;
+ }
+}
+
+@ @<Scan all the text nodes and mark the used ...@>=
+p=hh->body;
+while ( p!=null ) {
+ if ( gr_type(p)==mp_text_code ) {
+ f = gr_font_n(p);
+ if (f!=null_font ) {
+ switch (prologues) {
+ case 2:
+ case 3:
+ mp->font_sizes[f] = mp_void;
+ mp_mark_string_chars(mp, f, gr_text_p(p),gr_text_l(p));
+ if (mp_has_fm_entry(mp,f,NULL) ) {
+ if (mp->font_enc_name[f]==NULL )
+ mp->font_enc_name[f] = mp_fm_encoding_name(mp,f);
+ mp->font_ps_name[f] = mp_fm_font_name(mp,f);
+ }
+ break;
+ case 1:
+ mp->font_sizes[f]=mp_void;
+ break;
+ default:
+ gr_size_index(p)=(unsigned char)mp_size_index(mp, f,mp_choose_scale(mp, p));
+ if ( gr_size_index(p)==0 )
+ mp_mark_string_chars(mp, f, gr_text_p(p),gr_text_l(p));
+ }
+ }
+ }
+ p=gr_link(p);
+}
+
+
+@
+@d pen_is_elliptical(A) ((A)==gr_next_knot((A)))
+
+@<Exported function ...@>=
+int mp_gr_ship_out (mp_edge_object *hh, int prologues, int procset, int standalone) ;
+
+@ @c
+int mp_gr_ship_out (mp_edge_object *hh, int qprologues, int qprocset,int standalone) {
+ mp_graphic_object *p;
+ scaled ds,scf; /* design size and scale factor for a text node */
+ font_number f; /* for loops over fonts while (un)marking characters */
+ boolean transformed; /* is the coordinate system being transformed? */
+ int prologues, procset;
+ MP mp = hh->parent;
+ if (standalone) {
+ mp->jump_buf = malloc(sizeof(jmp_buf));
+ if (mp->jump_buf == NULL || setjmp(*(mp->jump_buf)))
+ return 0;
+ }
+ if (mp->history >= mp_fatal_error_stop ) return 1;
+ if (qprologues<0)
+ prologues = (int)((unsigned)mp->internal[mp_prologues]>>16);
+ else
+ prologues=qprologues;
+ if (qprocset<0)
+ procset = (int)((unsigned)mp->internal[mp_procset]>>16);
+ else
+ procset=qprocset;
+ mp_open_output_file(mp);
+ mp_print_initial_comment(mp, hh, prologues);
+ p = hh->body;
+ @<Unmark all marked characters@>;
+ if ( prologues==2 || prologues==3 ) {
+ mp_reload_encodings(mp);
+ }
+ @<Scan all the text nodes and mark the used characters@>;
+ if ( prologues==2 || prologues==3 ) {
+ mp_print_improved_prologue(mp, hh, prologues, procset);
+ } else {
+ mp_print_prologue(mp, hh, prologues, procset);
+ }
+ mp_gs_unknown_graphics_state(mp, 0);
+ p = hh->body;
+ while ( p!=NULL ) {
+ if ( gr_has_color(p) ) {
+ @<Write |pre_script| of |p|@>;
+ }
+ mp_gr_fix_graphics_state(mp, p);
+ switch (gr_type(p)) {
+ case mp_fill_code:
+ if ( gr_pen_p((mp_fill_object *)p)==NULL ) {
+ mp_gr_ps_fill_out(mp, gr_path_p((mp_fill_object *)p));
+ } else if ( pen_is_elliptical(gr_pen_p((mp_fill_object *)p)) ) {
+ mp_gr_stroke_ellipse(mp, p,true);
+ } else {
+ mp_gr_ps_fill_out(mp, gr_path_p((mp_fill_object *)p));
+ mp_gr_ps_fill_out(mp, gr_htap_p(p));
+ }
+ if ( gr_post_script((mp_fill_object *)p)!=NULL ) {
+ mp_ps_print_nl (mp, gr_post_script((mp_fill_object *)p));
+ mp_ps_print_ln(mp);
+ }
+ break;
+ case mp_stroked_code:
+ if ( pen_is_elliptical(gr_pen_p((mp_stroked_object *)p)) )
+ mp_gr_stroke_ellipse(mp, p,false);
+ else {
+ mp_gr_ps_fill_out(mp, gr_path_p((mp_stroked_object *)p));
+ }
+ if ( gr_post_script((mp_stroked_object *)p)!=NULL ) {
+ mp_ps_print_nl (mp, gr_post_script((mp_stroked_object *)p));
+ mp_ps_print_ln(mp);
+ }
+ break;
+ case mp_text_code:
+ if ( (gr_font_n(p)!=null_font) && (gr_text_l(p)>0) ) {
+ if ( prologues>0 )
+ scf=mp_gr_choose_scale(mp, p);
+ else
+ scf=mp_indexed_size(mp, gr_font_n(p), (quarterword)gr_size_index(p));
+ @<Shift or transform as necessary before outputting text node~|p| at scale
+ factor~|scf|; set |transformed:=true| if the original transformation must
+ be restored@>;
+ mp_ps_string_out(mp, gr_text_p(p),gr_text_l(p));
+ mp_ps_name_out(mp, mp->font_name[gr_font_n(p)],false);
+ @<Print the size information and \ps\ commands for text node~|p|@>;
+ mp_ps_print_ln(mp);
+ }
+ if ( gr_post_script((mp_text_object *)p)!=NULL ) {
+ mp_ps_print_nl (mp, gr_post_script((mp_text_object *)p)); mp_ps_print_ln(mp);
+ }
+ break;
+ case mp_start_clip_code:
+ mp_ps_print_nl(mp, ""); mp_ps_print_cmd(mp, "gsave ","q ");
+ mp_gr_ps_path_out(mp, gr_path_p((mp_clip_object *)p));
+ mp_ps_print_cmd(mp, " clip"," W");
+ mp_ps_print_ln(mp);
+ if ( mp->internal[mp_restore_clip_color]>0 )
+ mp_gs_unknown_graphics_state(mp, 1);
+ break;
+ case mp_stop_clip_code:
+ mp_ps_print_nl(mp, ""); mp_ps_print_cmd(mp, "grestore","Q");
+ mp_ps_print_ln(mp);
+ if ( mp->internal[mp_restore_clip_color]>0 )
+ mp_gs_unknown_graphics_state(mp, 2);
+ else
+ mp_gs_unknown_graphics_state(mp, -1);
+ break;
+ case mp_start_bounds_code:
+ case mp_stop_bounds_code:
+ break;
+ case mp_special_code:
+ {
+ mp_special_object *ps = (mp_special_object *)p;
+ mp_ps_print_nl (mp, gr_pre_script(ps));
+ mp_ps_print_ln (mp);
+ }
+ break;
+ } /* all cases are enumerated */
+ p=gr_link(p);
+ }
+ mp_ps_print_cmd(mp, "showpage","P"); mp_ps_print_ln(mp);
+ mp_ps_print(mp, "%%EOF"); mp_ps_print_ln(mp);
+ (mp->close_file)(mp,mp->output_file);
+ if ( prologues<=0 )
+ mp_clear_sizes(mp);
+ return 1;
+}
+
+@ @(mplibps.h@>=
+int mp_ps_ship_out (mp_edge_object *hh, int prologues, int procset) ;
+
+@ @c
+int mp_ps_ship_out (mp_edge_object *hh, int prologues, int procset) {
+ return mp_gr_ship_out (hh, prologues, procset, (int)true);
+}
+
+
+
+
+
+@
+@d do_write_prescript(a,b) {
+ if ( (gr_pre_script((b *)a))!=NULL ) {
+ mp_ps_print_nl (mp, gr_pre_script((b *)a));
+ mp_ps_print_ln(mp);
+ }
+}
+
+@<Write |pre_script| of |p|@>=
+{
+ if (gr_type(p)==mp_fill_code) { do_write_prescript(p,mp_fill_object); }
+ else if (gr_type(p)==mp_stroked_code) { do_write_prescript(p,mp_stroked_object); }
+ else if (gr_type(p)==mp_text_code) { do_write_prescript(p,mp_text_object); }
+}
+
+@ @<Print the size information and \ps\ commands for text node~|p|@>=
+ps_room(18);
+mp_ps_print_char(mp, ' ');
+ds=(mp->font_dsize[gr_font_n(p)]+8) / 16;
+mp_ps_print_scaled(mp, mp_take_scaled(mp, ds,scf));
+mp_ps_print(mp, " fshow");
+if ( transformed )
+ mp_ps_print_cmd(mp, " grestore"," Q")
+
+
+
+@ @<Shift or transform as necessary before outputting text node~|p| at...@>=
+transformed=(gr_txx_val(p)!=scf)||(gr_tyy_val(p)!=scf)||
+ (gr_txy_val(p)!=0)||(gr_tyx_val(p)!=0);
+if ( transformed ) {
+ mp_ps_print_cmd(mp, "gsave [", "q [");
+ mp_ps_pair_out(mp, mp_make_scaled(mp, gr_txx_val(p),scf),
+ mp_make_scaled(mp, gr_tyx_val(p),scf));
+ mp_ps_pair_out(mp, mp_make_scaled(mp, gr_txy_val(p),scf),
+ mp_make_scaled(mp, gr_tyy_val(p),scf));
+ mp_ps_pair_out(mp, gr_tx_val(p),gr_ty_val(p));
+ mp_ps_print_cmd(mp, "] concat 0 0 moveto","] t 0 0 m");
+} else {
+ mp_ps_pair_out(mp, gr_tx_val(p),gr_ty_val(p));
+ mp_ps_print_cmd(mp, "moveto","m");
+}
+mp_ps_print_ln(mp)
+
+@ @(mplibps.h@>=
+void mp_gr_toss_objects ( mp_edge_object *hh) ;
+void mp_gr_toss_object (mp_graphic_object *p) ;
+
+@ @c
+void mp_gr_toss_object (mp_graphic_object *p) {
+ mp_fill_object *tf;
+ mp_stroked_object *ts;
+ mp_text_object *tt;
+ switch (gr_type(p)) {
+ case mp_fill_code:
+ tf = (mp_fill_object *)p;
+ mp_xfree(gr_pre_script(tf));
+ mp_xfree(gr_post_script(tf));
+ mp_gr_toss_knot_list(mp,gr_pen_p(tf));
+ mp_gr_toss_knot_list(mp,gr_path_p(tf));
+ mp_gr_toss_knot_list(mp,gr_htap_p(p));
+ break;
+ case mp_stroked_code:
+ ts = (mp_stroked_object *)p;
+ mp_xfree(gr_pre_script(ts));
+ mp_xfree(gr_post_script(ts));
+ mp_gr_toss_knot_list(mp,gr_pen_p(ts));
+ mp_gr_toss_knot_list(mp,gr_path_p(ts));
+ if (gr_dash_p(p)!=NULL)
+ mp_gr_toss_dashes (mp,gr_dash_p(p));
+ break;
+ case mp_text_code:
+ tt = (mp_text_object *)p;
+ mp_xfree(gr_pre_script(tt));
+ mp_xfree(gr_post_script(tt));
+ mp_xfree(gr_text_p(p));
+ mp_xfree(gr_font_name(p));
+ break;
+ case mp_start_clip_code:
+ mp_gr_toss_knot_list(mp,gr_path_p((mp_clip_object *)p));
+ break;
+ case mp_start_bounds_code:
+ mp_gr_toss_knot_list(mp,gr_path_p((mp_bounds_object *)p));
+ break;
+ case mp_stop_clip_code:
+ case mp_stop_bounds_code:
+ break;
+ case mp_special_code:
+ mp_xfree(gr_pre_script((mp_special_object *)p));
+ break;
+ } /* all cases are enumerated */
+ mp_xfree(p);
+}
+
+
+@ @c
+void mp_gr_toss_objects (mp_edge_object *hh) {
+ mp_graphic_object *p, *q;
+ p = hh->body;
+ while ( p!=NULL ) {
+ q = gr_link(p);
+ mp_gr_toss_object(p);
+ p=q;
+ }
+ mp_xfree(hh->filename);
+ mp_xfree(hh);
+}
+
+@ @(mplibps.h@>=
+mp_graphic_object *mp_gr_copy_object (MP mp, mp_graphic_object *p) ;
+
+@ @c
+mp_graphic_object *
+mp_gr_copy_object (MP mp, mp_graphic_object *p) {
+ mp_fill_object *tf;
+ mp_stroked_object *ts;
+ mp_text_object *tt;
+ mp_clip_object *tc;
+ mp_bounds_object *tb;
+ mp_special_object *tp;
+ mp_graphic_object *q = NULL;
+ switch (gr_type(p)) {
+ case mp_fill_code:
+ tf = (mp_fill_object *)mp_new_graphic_object(mp, mp_fill_code);
+ gr_pre_script(tf) = mp_xstrdup(mp, gr_pre_script((mp_fill_object *)p));
+ gr_post_script(tf) = mp_xstrdup(mp, gr_post_script((mp_fill_object *)p));
+ gr_path_p(tf) = mp_gr_copy_path(mp,gr_path_p((mp_fill_object *)p));
+ gr_htap_p(tf) = mp_gr_copy_path(mp,gr_htap_p(p));
+ gr_pen_p(tf) = mp_gr_copy_path(mp,gr_pen_p((mp_fill_object *)p));
+ q = (mp_graphic_object *)tf;
+ break;
+ case mp_stroked_code:
+ ts = (mp_stroked_object *)mp_new_graphic_object(mp, mp_stroked_code);
+ gr_pre_script(ts) = mp_xstrdup(mp, gr_pre_script((mp_stroked_object *)p));
+ gr_post_script(ts) = mp_xstrdup(mp, gr_post_script((mp_stroked_object *)p));
+ gr_path_p(ts) = mp_gr_copy_path(mp,gr_path_p((mp_stroked_object *)p));
+ gr_pen_p(ts) = mp_gr_copy_path(mp,gr_pen_p((mp_stroked_object *)p));
+ gr_dash_p(ts) = mp_gr_copy_dashes(mp,gr_dash_p(p));
+ q = (mp_graphic_object *)ts;
+ break;
+ case mp_text_code:
+ tt = (mp_text_object *)mp_new_graphic_object(mp, mp_text_code);
+ gr_pre_script(tt) = mp_xstrdup(mp, gr_pre_script((mp_text_object *)p));
+ gr_post_script(tt) = mp_xstrdup(mp, gr_post_script((mp_text_object *)p));
+ gr_text_p(tt) = mp_xstrldup(mp, gr_text_p(p), gr_text_l(p));
+ gr_text_l(tt) = gr_text_l(p);
+ gr_font_name(tt) = mp_xstrdup(mp, gr_font_name(p));
+ q = (mp_graphic_object *)tt;
+ break;
+ case mp_start_clip_code:
+ tc = (mp_clip_object *)mp_new_graphic_object(mp, mp_start_clip_code);
+ gr_path_p(tc) = mp_gr_copy_path(mp,gr_path_p((mp_clip_object *)p));
+ q = (mp_graphic_object *)tc;
+ break;
+ case mp_start_bounds_code:
+ tb = (mp_bounds_object *)mp_new_graphic_object(mp, mp_start_bounds_code);
+ gr_path_p(tb) = mp_gr_copy_path(mp,gr_path_p((mp_bounds_object *)p));
+ q = (mp_graphic_object *)tb;
+ break;
+ case mp_special_code:
+ tp = (mp_special_object *)mp_new_graphic_object(mp, mp_special_code);
+ gr_pre_script(tp) = mp_xstrdup(mp, gr_pre_script((mp_special_object *)p));
+ q = (mp_graphic_object *)tp;
+ break;
+ case mp_stop_clip_code:
+ q = mp_new_graphic_object(mp, mp_stop_clip_code);
+ break;
+ case mp_stop_bounds_code:
+ q = mp_new_graphic_object(mp, mp_stop_bounds_code);
+ break;
+ } /* all cases are enumerated */
+ return q;
+}
+
diff --git a/Build/source/texk/web2c/mplibdir/svgout.w b/Build/source/texk/web2c/mplibdir/svgout.w
new file mode 100644
index 00000000000..22072530ac0
--- /dev/null
+++ b/Build/source/texk/web2c/mplibdir/svgout.w
@@ -0,0 +1,1314 @@
+% $Id: svgout.w 657 2008-10-08 09:48:49Z taco $
+%
+% Copyright 2008 Taco Hoekwater.
+%
+% This program is free software: you can redistribute it and/or modify
+% it under the terms of the GNU Lesser General Public License as published by
+% the Free Software Foundation, either version 3 of the License, or
+% (at your option) any later version.
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+% GNU Lesser General Public License for more details.
+%
+% You should have received a copy of the GNU Lesser General Public License
+% along with this program. If not, see <http://www.gnu.org/licenses/>.
+%
+% TeX is a trademark of the American Mathematical Society.
+% METAFONT is a trademark of Addison-Wesley Publishing Company.
+% PostScript is a trademark of Adobe Systems Incorporated.
+
+% Here is TeX material that gets inserted after \input webmac
+
+\font\tenlogo=logo10 % font used for the METAFONT logo
+\font\logos=logosl10
+\def\MF{{\tenlogo META}\-{\tenlogo FONT}}
+\def\MP{{\tenlogo META}\-{\tenlogo POST}}
+\def\<#1>{$\langle#1\rangle$}
+\def\section{\mathhexbox278}
+\def\[#1]{} % from pascal web
+\def\(#1){} % this is used to make section names sort themselves better
+\def\9#1{} % this is used for sort keys in the index via @@:sort key}{entry@@>
+
+\def\title{MetaPost SVG output}
+\def\topofcontents{\hsize 5.5in
+ \vglue -30pt plus 1fil minus 1.5in
+ \def\?##1]{\hbox to 1in{\hfil##1.\ }}
+ }
+\def\botofcontents{\vskip 0pt plus 1fil minus 1.5in}
+\pdfoutput=1
+\pageno=3
+
+@
+@d true 1
+@d false 0
+@d null_font 0
+@d null 0
+@d unity 0200000 /* $2^{16}$, represents 1.00000 */
+@d incr(A) (A)=(A)+1 /* increase a variable by unity */
+@d decr(A) (A)=(A)-1 /* decrease a variable by unity */
+@d negate(A) (A)=-(A) /* change the sign of a variable */
+
+@c
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "mplib.h"
+#include "mplibps.h" /* external header */
+#include "mpmp.h" /* internal header */
+#include "mppsout.h" /* internal header */
+#include "mpsvgout.h" /* internal header */
+@h
+@<Types in the outer block@>
+@<Declarations@>
+
+@ There is a small bit of code from the backend that bleads through
+to the frontend because I do not know how to set up the includes
+properly. That is |typedef struct svgout_data_struct * svgout_data|.
+
+@ @(mpsvgout.h@>=
+typedef struct svgout_data_struct {
+ @<Globals@>
+} svgout_data_struct ;
+@<Exported function headers@>
+
+@ @<Exported function headers@>=
+void mp_svg_backend_initialize (MP mp) ;
+void mp_svg_backend_free (MP mp) ;
+
+@ @c
+void mp_svg_backend_initialize (MP mp) {
+ mp->svg = mp_xmalloc(mp,1,sizeof(svgout_data_struct));
+ @<Set initial values@>;
+}
+void mp_svg_backend_free (MP mp) {
+ mp_xfree(mp->svg->buf);
+ mp_xfree(mp->svg);
+ mp->svg = NULL;
+}
+
+@ Writing to SVG files
+
+This variable holds the number of characters on the current SVG file
+line. It could also be a boolean because right now the only interesting
+thing it does is keep track of whether or not we are start-of-line.
+
+@<Globals@>=
+integer file_offset;
+
+@ @<Set initial values@>=
+mp->svg->file_offset = 0;
+
+@ Print a newline.
+
+@c
+static void mp_svg_print_ln (MP mp) {
+ (mp->write_ascii_file)(mp,mp->output_file,"\n");
+ mp->svg->file_offset=0;
+}
+
+@ Print a single character.
+
+@c
+static void mp_svg_print_char (MP mp, int s) {
+ char ss[2];
+ ss[0]=s; ss[1]=0;
+ (mp->write_ascii_file)(mp,mp->output_file,(char *)ss);
+ mp->svg->file_offset ++;
+}
+
+@ Print a string.
+
+In PostScript, this used to be done in terms of |mp_svg_print_char|,
+but that is very expensive (in other words: slow). It should be ok
+to print whole strings here because line length of an XML file should
+not be an issue to any respectable XML processing tool.
+
+@c
+static void mp_svg_print (MP mp, const char *ss) {
+ (mp->write_ascii_file)(mp,mp->output_file,(char *)ss);
+ mp->svg->file_offset += strlen(ss);
+}
+
+
+@ The procedure |print_nl| is like |print|, but it makes sure that the
+string appears at the beginning of a new line.
+
+@c
+static void mp_svg_print_nl (MP mp, const char *s) {
+ if ( mp->svg->file_offset>0 )
+ mp_svg_print_ln(mp);
+ mp_svg_print(mp, s);
+}
+
+
+@ Many of the printing routines use a print buffer to store partial
+strings in before feeding the attribute value to |mp_svg_attribute|.
+
+@<Globals...@>=
+char *buf;
+int loc;
+int bufsize;
+
+@ Start with a modest size of 256. the buffer will grow automatically
+when needed.
+
+@<Set initial values@>=
+mp->svg->loc = 0;
+mp->svg->bufsize = 256;
+mp->svg->buf = mp_xmalloc(mp,mp->svg->bufsize,1);
+memset(mp->svg->buf,0,256);
+
+
+@ How to append a character or a string of characters to
+the end of the buffer.
+
+@d append_char(A) do {
+ if (mp->svg->loc==(mp->svg->bufsize-1)) {
+ char *buffer;
+ unsigned l;
+ l = (unsigned)(mp->svg->bufsize+(mp->svg->bufsize>>4));
+ if (l>(0x3FFFFFF)) {
+ mp_confusion(mp,"svg buffer size");
+ }
+ buffer = mp_xmalloc(mp,l,1);
+ memset (buffer,0,l);
+ memcpy(buffer,mp->svg->buf,mp->svg->bufsize);
+ mp_xfree(mp->svg->buf);
+ mp->svg->buf = buffer ;
+ mp->svg->bufsize = l;
+ }
+ mp->svg->buf[mp->svg->loc++] = (A);
+} while (0)
+
+@d append_string(A) do {
+ char *ss = (A);
+ while (*ss != '\0') { append_char(*ss); ss++ ;}
+} while (0)
+
+@ This function resets the buffer in preparation of the next string.
+The |memset| is an easy way to make sure that the old string is
+forgotten completely and that the new string will be zero-terminated.
+
+@c
+static void mp_svg_reset_buf(MP mp) {
+ mp->svg->loc = 0;
+ memset (mp->svg->buf,0,mp->svg->bufsize);
+}
+
+@ Printing the buffer is a matter of printing its string, then
+it is reset.
+
+@c
+static void mp_svg_print_buf (MP mp) {
+ mp_svg_print(mp, (char *)mp->svg->buf);
+ mp_svg_reset_buf(mp);
+}
+
+@ The following procedure, which stores the decimal representation of
+a given integer |n| in the buffer, has been written carefully so that
+it works properly if |n=0| or if |(-n)| would cause overflow.
+
+@c
+static void mp_svg_store_int (MP mp,integer n) {
+ integer m; /* used to negate |n| in possibly dangerous cases */
+ int k = 0; /* index to current digit; we assume that $|n|<10^{23}$ */
+ if ( n<0 ) {
+ append_char('-');
+ if ( n>-100000000 ) {
+ negate(n);
+ } else {
+ m=-1-n; n=m / 10; m=(m % 10)+1; k=1;
+ if ( m<10 ) {
+ mp->dig[0]=(unsigned char)m;
+ } else {
+ mp->dig[0]=0; incr(n);
+ }
+ }
+ }
+ do {
+ mp->dig[k]=(unsigned char)(n % 10); n=n / 10; incr(k);
+ } while (n!=0);
+ /* print the digits */
+ while ( k-->0 ){
+ append_char('0'+mp->dig[k]);
+ }
+}
+
+@ \MP\ also makes use of a trivial procedure to output two digits. The
+following subroutine is usually called with a parameter in the range |0<=n<=99|,
+but the assignments makes sure that only the two least significant digits
+are printed, just in case.
+
+@c
+static void mp_svg_store_dd (MP mp,integer n) {
+ n=abs(n) % 100;
+ append_char('0'+(n / 10));
+ append_char('0'+(n % 10));
+}
+
+@ Conversely, here is a procedure analogous to |mp_svg_store_int|.
+A decimal point is printed only if the value is not an integer. If
+there is more than one way to print the result with the optimum
+number of digits following the decimal point, the closest possible
+value is given.
+
+The invariant relation in the \&{do while} loop is that a sequence of
+decimal digits yet to be printed will yield the original number if and only if
+they form a fraction~$f$ in the range $s-\delta\L10\cdot2^{16}f<s$.
+We can stop if and only if $f=0$ satisfies this condition; the loop will
+terminate before $s$ can possibly become zero.
+
+@c
+static void mp_svg_store_scaled (MP mp,scaled s) {
+ scaled delta; /* amount of allowable inaccuracy */
+ if ( s<0 ) {
+ append_char('-');
+ negate(s); /* print the sign, if negative */
+ }
+ mp_svg_store_int(mp, s / unity); /* print the integer part */
+ s=10*(s % unity)+5;
+ if ( s!=5 ) {
+ delta=10;
+ append_char('.');
+ do {
+ if ( delta>unity )
+ s=s+0100000-(delta / 2); /* round the final digit */
+ append_char('0'+(s / unity));
+ s=10*(s % unity);
+ delta=delta*10;
+ } while (s>delta);
+ }
+}
+
+
+@ Output XML tags.
+
+In order to create a nicely indented output file, the current tag
+nesting level needs to be remembered.
+
+@<Globals...@>=
+int level;
+
+@ @<Set initial values@>=
+mp->svg->level = 0;
+
+@ Output an XML start tag.
+
+Because start tags may carry attributes, this happens in two steps.
+The close function is trivial of course, but it looks nicer in the source.
+
+@d mp_svg_starttag(A,B) { mp_svg_open_starttag (A,B); mp_svg_close_starttag(A); }
+
+@c
+static void mp_svg_open_starttag (MP mp, char *s) {
+ int l = mp->svg->level * 2;
+ mp_svg_print_ln(mp);
+ while (l-->0) {
+ append_char(' ');
+ }
+ append_char('<');
+ append_string(s);
+ mp_svg_print_buf(mp);
+ mp->svg->level++;
+}
+static void mp_svg_close_starttag (MP mp) {
+ mp_svg_print_char(mp,'>');
+}
+
+@ Output an XML end tag.
+
+If the |indent| is true, then the end tag will appear on the next line
+of the SVG file, correctly indented for the current XML nesting
+level. If it is false, the end tag will appear immediatelu after the
+preceding output.
+
+@c
+static void mp_svg_endtag (MP mp, char *s, boolean indent) {
+ mp->svg->level--;
+ if (indent) {
+ int l = mp->svg->level * 2;
+ mp_svg_print_ln(mp);
+ while (l-->0) {
+ append_char(' ');
+ }
+ }
+ append_string("</");
+ append_string(s);
+ append_char('>');
+ mp_svg_print_buf(mp);
+}
+
+@ Attribute. Can't play with the buffer here becase it is likely
+that that is the |v| argument.
+
+@c
+static void mp_svg_attribute (MP mp, char *s, char *v) {
+ mp_svg_print_char(mp, ' ');
+ mp_svg_print(mp, s);
+ mp_svg_print(mp,"=\"");
+ mp_svg_print(mp, v);
+ mp_svg_print_char(mp,'"');
+}
+
+@ This is a test to filter out characters that are illegal in XML.
+
+@<Character |k| is illegal in SVG output@>=
+ (k<=0x8)||(k==0xB)||(k==0xC)||(k>=0xE && k<=0x1F)||
+ (k>=0x7F && k<=0x84)||(k>=0x86 && k<=0x9F)
+
+
+@ This is test is used to switch between direct representation of characters
+and character references. Just in case the input string is UTF-8, allow everything
+except the characters that have to be quoted for XML well-formedness.
+
+@<Character |k| is not allowed in SVG output@>=
+ (k=='&')||(k=='>')||(k=='<')
+
+@ We often need to print a pair of coordinates.
+
+Because of bugs in svg rendering software, it is necessary to
+change the point coordinates so that there are all in the "positive"
+quadrant of the SVG field. This means an shift and a vertical flip.
+
+The two correction values are calculated by the function that writes
+the initial |<svg>| tag, and are stored in two globals:
+
+@<Globals@>=
+integer dx;
+integer dy;
+
+@ @c
+void mp_svg_pair_out (MP mp,scaled x, scaled y) {
+ mp_svg_store_scaled(mp, (x+mp->svg->dx));
+ append_char(' ');
+ mp_svg_store_scaled(mp, (-(y+mp->svg->dy)));
+}
+
+@ @c
+void mp_svg_font_pair_out (MP mp,scaled x, scaled y) {
+ mp_svg_store_scaled(mp, (x));
+ append_char(' ');
+ mp_svg_store_scaled(mp, -(y));
+}
+
+@ When stroking a path with an elliptical pen, it is necessary to distort
+the path such that a circular pen can be used to stroke the path. The path
+itself is wrapped in another transformation to restore the points to their
+correct location (but now with a modified pen stroke).
+
+Because all the points in the path need fixing, it makes sense to
+have a specific helper to write such distorted pairs of coordinates out.
+
+@d scaled_from_double(a) (scaled)((a)*65536.0)
+@d double_from_scaled(a) (double)((a)/65536.0)
+
+@c
+void mp_svg_trans_pair_out (MP mp, mp_pen_info *pen, scaled x, scaled y) {
+ double sx,sy, rx,ry, px, py, retval, divider;
+ sx = double_from_scaled(pen->sx);
+ sy = double_from_scaled(pen->sy);
+ rx = double_from_scaled(pen->rx);
+ ry = double_from_scaled(pen->ry);
+ px = double_from_scaled((x+mp->svg->dx));
+ py = double_from_scaled((-(y+mp->svg->dy)));
+ divider = (sx*sy - rx*ry);
+ retval = (sy*px-ry*py)/divider;
+ mp_svg_store_scaled(mp, scaled_from_double(retval));
+ append_char(' ');
+ retval = (sx*py-rx*px)/divider;
+ mp_svg_store_scaled(mp, scaled_from_double(retval));
+}
+
+
+
+@ @<Declarations@>=
+static void mp_svg_pair_out (MP mp,scaled x, scaled y) ;
+
+@
+@<Declarations@>=
+static void mp_svg_print_initial_comment(MP mp,mp_edge_object *hh);
+
+@ @c
+void mp_svg_print_initial_comment(MP mp,mp_edge_object *hh) {
+ scaled t, tx, ty;
+ mp_svg_print(mp, "<?xml version=\"1.0\"?>");
+ @<Print the MetaPost version and time @>;
+ mp_svg_open_starttag(mp,"svg");
+ mp_svg_attribute(mp,"version", "1.1");
+ mp_svg_attribute(mp,"xmlns", "http://www.w3.org/2000/svg");
+ mp_svg_attribute(mp, "xmlns:xlink", "http://www.w3.org/1999/xlink");
+ if ( hh->minx>hh->maxx) {
+ tx = 0;
+ ty = 0;
+ mp->svg->dx = 0;
+ mp->svg->dy = 0;
+ } else {
+ tx = (hh->minx<0 ? -hh->minx : 0) + hh->maxx;
+ ty = (hh->miny<0 ? -hh->miny : 0) + hh->maxy;
+ mp->svg->dx = (hh->minx<0 ? -hh->minx : 0);
+ mp->svg->dy = (hh->miny<0 ? -hh->miny : 0) - ty;
+ }
+ mp_svg_store_scaled(mp, tx);
+ mp_svg_attribute(mp,"width", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ mp_svg_store_scaled(mp, ty);
+ mp_svg_attribute(mp,"height", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ append_string("0 0 "); mp_svg_store_scaled(mp,tx);
+ append_char(' '); mp_svg_store_scaled(mp,ty);
+ mp_svg_attribute(mp,"viewBox", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ mp_svg_close_starttag(mp);
+ mp_svg_print_nl(mp,"<!-- Original BoundingBox: ");
+ mp_svg_store_scaled(mp, hh->minx); append_char(' ');
+ mp_svg_store_scaled(mp, hh->miny); append_char(' ');
+ mp_svg_store_scaled(mp, hh->maxx); append_char(' ');
+ mp_svg_store_scaled(mp, hh->maxy);
+ mp_svg_print_buf(mp);
+ mp_svg_print(mp," -->");
+}
+
+@ @<Print the MetaPost version and time @>=
+{
+ char *s;
+ mp_svg_print_nl(mp, "<!-- Created by MetaPost ");
+ s = mp_metapost_version();
+ mp_svg_print(mp, s);
+ mp_xfree(s);
+ mp_svg_print(mp, " on ");
+ mp_svg_store_int(mp, mp_round_unscaled(mp, mp->internal[mp_year]));
+ append_char('.');
+ mp_svg_store_dd(mp, mp_round_unscaled(mp, mp->internal[mp_month]));
+ append_char('.');
+ mp_svg_store_dd(mp, mp_round_unscaled(mp, mp->internal[mp_day]));
+ append_char(':');
+ t=mp_round_unscaled(mp, mp->internal[mp_time]);
+ mp_svg_store_dd(mp, t / 60);
+ mp_svg_store_dd(mp, t % 60);
+ mp_svg_print_buf(mp);
+ mp_svg_print(mp, " -->");
+}
+
+
+@ Outputting a color specification.
+
+@d set_color_objects(pq)
+ object_color_model = pq->color_model;
+ object_color_a = pq->color.a_val;
+ object_color_b = pq->color.b_val;
+ object_color_c = pq->color.c_val;
+ object_color_d = pq->color.d_val;
+
+@c
+static void mp_svg_color_out (MP mp, mp_graphic_object *p) {
+ int object_color_model;
+ int object_color_a, object_color_b, object_color_c, object_color_d ;
+ if (gr_type(p) == mp_fill_code) {
+ mp_fill_object *pq = (mp_fill_object *)p;
+ set_color_objects(pq);
+ } else if (gr_type(p) == mp_stroked_code) {
+ mp_stroked_object *pq = (mp_stroked_object *)p;
+ set_color_objects(pq);
+ } else {
+ mp_text_object *pq = (mp_text_object *)p;
+ set_color_objects(pq);
+ }
+ if ( object_color_model==mp_no_model ) {
+ append_string("black");
+ } else {
+ if ( object_color_model==mp_grey_model ) {
+ object_color_b = object_color_a;
+ object_color_c = object_color_a;
+ } else if ( object_color_model==mp_cmyk_model) {
+ int c,m,y,k;
+ c = object_color_a;
+ m = object_color_b;
+ y = object_color_c;
+ k = object_color_d;
+ object_color_a = unity - (c+k>unity ? unity : c+k);
+ object_color_b = unity - (m+k>unity ? unity : m+k);
+ object_color_c = unity - (y+k>unity ? unity : y+k);
+ }
+ append_string("rgb(");
+ mp_svg_store_scaled(mp, (object_color_a * 100));
+ append_char('%');
+ append_char(',');
+ mp_svg_store_scaled(mp, (object_color_b * 100));
+ append_char('%');
+ append_char(',');
+ mp_svg_store_scaled(mp, (object_color_c * 100));
+ append_char('%');
+ append_char(')');
+ }
+}
+
+@ @<Declarations@>=
+static void mp_svg_color_out (MP mp, mp_graphic_object *p);
+
+@ This is the information that comes from a pen
+
+@<Types...@>=
+typedef struct mp_pen_info {
+ scaled tx, ty;
+ scaled sx, rx, ry, sy;
+ scaled ww;
+} mp_pen_info;
+
+
+@ (Re)discover the characteristics of an elliptical pen
+
+@<Declarations@>=
+mp_pen_info *mp_svg_pen_info(MP mp, mp_knot *pp, mp_knot *p);
+
+@ The next two constants come from the original web source.
+Together with the two helper functions, they will tell whether
+the |x| or the |y| direction of the path is the most important
+
+@d aspect_bound 10
+@d aspect_default 1
+
+@c
+static scaled coord_range_x (mp_knot *h, scaled dz) {
+ scaled z;
+ scaled zlo = 0, zhi = 0;
+ mp_knot *f = h;
+ while (h != NULL) {
+ z = gr_x_coord(h);
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ z = gr_right_x(h);
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ z = gr_left_x(h);
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ h = gr_next_knot(h);
+ if (h==f)
+ break;
+ }
+ return (zhi - zlo <= dz ? aspect_bound : aspect_default);
+}
+static scaled coord_range_y (mp_knot *h, scaled dz) {
+ scaled z;
+ scaled zlo = 0, zhi = 0;
+ mp_knot *f = h;
+ while (h != NULL) {
+ z = gr_y_coord(h);
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ z = gr_right_y(h);
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ z = gr_left_y(h);
+ if (z < zlo) zlo = z; else if (z > zhi) zhi = z;
+ h = gr_next_knot(h);
+ if (h==f)
+ break;
+ }
+ return (zhi - zlo <= dz ? aspect_bound : aspect_default);
+}
+
+@
+@c
+mp_pen_info *mp_svg_pen_info(MP mp, mp_knot *pp, mp_knot *p) {
+ scaled wx, wy; /* temporary pen widths, in either direction */
+ struct mp_pen_info *pen; /* return structure */
+ if (p == NULL)
+ return NULL;
+ pen = mp_xmalloc(mp, 1, sizeof(mp_pen_info));
+ pen->rx = unity;
+ pen->ry = unity;
+ pen->ww = unity;
+ if ((gr_right_x(p) == gr_x_coord(p))
+ &&
+ (gr_left_y(p) == gr_y_coord(p))) {
+ wx = abs(gr_left_x(p) - gr_x_coord(p));
+ wy = abs(gr_right_y(p) - gr_y_coord(p));
+ } else {
+ wx = mp_pyth_add(mp, gr_left_x(p)-gr_x_coord(p),
+ gr_right_x(p)-gr_x_coord(p));
+ wy = mp_pyth_add(mp, gr_left_y(p)-gr_y_coord(p),
+ gr_right_y(p)-gr_y_coord(p));
+ }
+ if ((wy/coord_range_x(pp, wx)) >= (wx/coord_range_y(pp, wy)))
+ pen->ww = wy;
+ else
+ pen->ww = wx;
+ pen->tx = gr_x_coord(p);
+ pen->ty = gr_y_coord(p);
+ pen->sx = gr_left_x(p) - pen->tx;
+ pen->rx = gr_left_y(p) - pen->ty;
+ pen->ry = gr_right_x(p) - pen->tx;
+ pen->sy = gr_right_y(p) - pen->ty;
+ if (pen->ww != unity) {
+ if (pen->ww == 0) {
+ pen->sx = unity;
+ pen->sy = unity;
+ } else {
+ pen->rx = mp_make_scaled(mp, pen->rx, pen->ww);
+ pen->ry = mp_make_scaled(mp, pen->ry, pen->ww);
+ pen->sx = mp_make_scaled(mp, pen->sx, pen->ww);
+ pen->sy = mp_make_scaled(mp, pen->sy, pen->ww);
+ }
+ }
+ return pen;
+}
+
+@ Two types of straight lines come up often in \MP\ paths:
+cubics with zero initial and final velocity as created by |make_path| or
+|make_envelope|, and cubics with control points uniformly spaced on a line
+as created by |make_choices|.
+
+@<Declarations@>=
+static boolean mp_is_curved(mp_knot *p, mp_knot *q) ;
+
+
+@
+@d bend_tolerance 131 /* allow rounding error of $2\cdot10^{-3}$ */
+
+@c
+boolean mp_is_curved(mp_knot *p, mp_knot *q) {
+ scaled d; /* a temporary value */
+ if ( gr_right_x(p)==gr_x_coord(p) )
+ if ( gr_right_y(p)==gr_y_coord(p) )
+ if ( gr_left_x(q)==gr_x_coord(q) )
+ if ( gr_left_y(q)==gr_y_coord(q) )
+ return false;
+ d=gr_left_x(q)-gr_right_x(p);
+ if ( abs(gr_right_x(p)-gr_x_coord(p)-d)<=bend_tolerance )
+ if ( abs(gr_x_coord(q)-gr_left_x(q)-d)<=bend_tolerance ) {
+ d=gr_left_y(q)-gr_right_y(p);
+ if ( abs(gr_right_y(p)-gr_y_coord(p)-d)<=bend_tolerance )
+ if ( abs(gr_y_coord(q)-gr_left_y(q)-d)<=bend_tolerance )
+ return false;
+ }
+ return true;
+}
+
+
+@ @c
+static void mp_svg_path_out (MP mp, mp_knot *h) {
+ mp_knot *p, *q; /* for scanning the path */
+ append_char('M');
+ mp_svg_pair_out(mp, gr_x_coord(h),gr_y_coord(h));
+ p=h;
+ do {
+ if ( gr_right_type(p)==mp_endpoint ) {
+ if ( p==h ) {
+ append_string("l0 0");
+ }
+ return;
+ }
+ q=gr_next_knot(p);
+ if (mp_is_curved(p, q)){
+ append_char('C');
+ mp_svg_pair_out(mp, gr_right_x(p),gr_right_y(p));
+ append_char(',');
+ mp_svg_pair_out(mp, gr_left_x(q),gr_left_y(q));
+ append_char(',');
+ mp_svg_pair_out(mp, gr_x_coord(q),gr_y_coord(q));
+ } else if ( q!=h ){
+ append_char('L');
+ mp_svg_pair_out(mp, gr_x_coord(q),gr_y_coord(q));
+ }
+ p=q;
+ } while (p!=h);
+ append_char('Z');
+ append_char(0);
+}
+
+@ @c
+static void mp_svg_path_trans_out (MP mp, mp_knot *h, mp_pen_info *pen) {
+ mp_knot *p, *q; /* for scanning the path */
+ append_char('M');
+ mp_svg_trans_pair_out(mp, pen, gr_x_coord(h),gr_y_coord(h));
+ p=h;
+ do {
+ if ( gr_right_type(p)==mp_endpoint ) {
+ if ( p==h ) {
+ append_string("l0 0");
+ }
+ return;
+ }
+ q=gr_next_knot(p);
+ if (mp_is_curved(p, q)){
+ append_char('C');
+ mp_svg_trans_pair_out(mp, pen, gr_right_x(p),gr_right_y(p));
+ append_char(',');
+ mp_svg_trans_pair_out(mp, pen,gr_left_x(q),gr_left_y(q));
+ append_char(',');
+ mp_svg_trans_pair_out(mp, pen,gr_x_coord(q),gr_y_coord(q));
+ } else if ( q!=h ){
+ append_char('L');
+ mp_svg_print(mp, "L ");
+ mp_svg_trans_pair_out(mp, pen,gr_x_coord(q),gr_y_coord(q));
+ }
+ p=q;
+ } while (p!=h);
+ append_char('Z');
+ append_char(0);
+}
+
+
+@ @c
+static void mp_svg_font_path_out (MP mp, mp_knot *h) {
+ mp_knot *p, *q; /* for scanning the path */
+ append_char('M');
+ mp_svg_font_pair_out(mp, gr_x_coord(h),gr_y_coord(h));
+ p=h;
+ do {
+ if ( gr_right_type(p)==mp_endpoint ) {
+ if ( p==h ) {
+ append_char('l');
+ mp_svg_font_pair_out(mp, 0, 0);
+ }
+ return;
+ }
+ q=gr_next_knot(p);
+ if (mp_is_curved(p, q)){
+ append_char('C');
+ mp_svg_font_pair_out(mp, gr_right_x(p),gr_right_y(p));
+ append_char(',');
+ mp_svg_font_pair_out(mp, gr_left_x(q),gr_left_y(q));
+ append_char(',');
+ mp_svg_font_pair_out(mp, gr_x_coord(q),gr_y_coord(q));
+ } else if ( q!=h ){
+ append_char('L');
+ mp_svg_font_pair_out(mp, gr_x_coord(q),gr_y_coord(q));
+ }
+ p=q;
+ } while (p!=h);
+ append_char(0);
+}
+
+@ If |prologues:=3|, any glyphs in labels will be converted into paths.
+
+@d do_mark(A,B) do {
+ if (mp_chars == NULL) {
+ mp_chars = mp_xmalloc(mp, mp->font_max, sizeof(int *));
+ memset(mp_chars, 0, (mp->font_max * sizeof(int *)));
+ }
+ if (mp_chars[(A)] == NULL) {
+ int *glfs = mp_xmalloc(mp, 256, sizeof(int));
+ memset(glfs, 0, (256 * sizeof(int)));
+ mp_chars[(A)] = glfs;
+ }
+ mp_chars[(A)][(int)(B)] = 1;
+} while (0)
+
+@c
+void mp_svg_print_glyph_defs (MP mp, mp_edge_object *h) {
+ mp_graphic_object *p; /* object index */
+ int k, l; /* general purpose indices */
+ int **mp_chars = NULL; /* a twodimensional array of used glyphs */
+ mp_ps_font *f = NULL;
+ mp_edge_object *ch;
+ p = h->body;
+ while ( p!=NULL ) {
+ l = gr_text_l(p);
+ if ((gr_type(p) == mp_text_code) &&
+ (gr_font_n(p)!=null_font) &&
+ (l>0) ) {
+ char *s = gr_text_p(p);
+ while (l-->0) {
+ do_mark(gr_font_n(p), *s);
+ s++;
+ }
+ }
+ p=gr_link(p);
+ }
+ if (mp_chars != NULL) {
+ mp_svg_starttag(mp,"defs");
+ for (k=0;k<(int)mp->font_max;k++) {
+ if (mp_chars[k] != NULL ) {
+ double scale; /* the next gives rounding errors */
+ scaled ds,dx,sk;
+ ds =(mp->font_dsize[k]+8) / 16;
+ scale = (1/1000.0) * double_from_scaled(ds);
+ ds = scaled_from_double(scale);
+ dx = ds;
+ sk = 0;
+ for (l=0;l<256;l++) {
+ if (mp_chars[k][l] == 1) {
+ if (f == NULL) {
+ f = mp_ps_font_parse(mp, k);
+ if (f->extend != 0) {
+ dx = scaled_from_double(((double)f->extend / 1000.0) * scale);
+ }
+ if (f->slant != 0) {
+ sk = scaled_from_double(((double)f->slant / 1000.0) * 90);
+ }
+ }
+ mp_svg_open_starttag(mp,"g");
+ append_string("scale(");
+ mp_svg_store_scaled(mp,dx);
+ append_char(',');
+ mp_svg_store_scaled(mp,ds);
+ append_char(')');
+ if (sk!=0) {
+ append_string(" skewX(");
+ mp_svg_store_scaled(mp,-sk);
+ append_char(')');
+ }
+ mp_svg_attribute(mp, "transform", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+
+ append_string("GLYPH");
+ append_string(mp->font_name[k]);
+ append_char('_');
+ mp_svg_store_int(mp,l);
+ mp_svg_attribute(mp, "id", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ mp_svg_close_starttag(mp);
+ if (f != NULL) {
+ ch = mp_ps_font_charstring(mp,f,l);
+ if (ch != NULL) {
+ p = ch->body;
+ mp_svg_open_starttag(mp,"path");
+ mp_svg_attribute(mp, "style", "fill-rule: evenodd;");
+ while (p!=NULL) {
+ mp_svg_font_path_out(mp, gr_path_p((mp_fill_object *)p));
+ p = gr_link(p);
+ }
+ mp_svg_attribute(mp, "d", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ mp_svg_close_starttag(mp);
+ mp_svg_endtag(mp,"path",false);
+ }
+ mp_gr_toss_objects(ch);
+ }
+ mp_svg_endtag(mp,"g",true);
+ }
+ }
+ if (f!=NULL) { mp_ps_font_free(mp, f); f = NULL; }
+ }
+ }
+ mp_svg_endtag(mp,"defs", true);
+
+ /* cleanup */
+ for (k=0;k<(int)mp->font_max;k++) {
+ mp_xfree(mp_chars[k]);
+ }
+ mp_xfree(mp_chars);
+ }
+}
+
+
+@ Now for outputting the actual graphic objects.
+
+@<Declarations@>=
+static void mp_svg_text_out (MP mp, mp_text_object *p, int prologues) ;
+
+@ @c
+void mp_svg_text_out (MP mp, mp_text_object *p, int prologues) {
+ char *s, *fname;
+ int k; /* a character */
+ int l; /* string length */
+ boolean transformed ;
+ scaled ds; /* design size and scale factor for a text node */
+ fname = mp->font_ps_name[gr_font_n(p)];
+ s = gr_text_p(p);
+ l = gr_text_l(p);
+ transformed=(gr_txx_val(p)!=unity)||(gr_tyy_val(p)!=unity)||
+ (gr_txy_val(p)!=0)||(gr_tyx_val(p)!=0);
+ mp_svg_open_starttag(mp, "g");
+ if ( transformed ) {
+ append_string("matrix(");
+ mp_svg_store_scaled(mp,gr_txx_val(p)); append_char(',');
+ mp_svg_store_scaled(mp,-gr_tyx_val(p)); append_char(',');
+ mp_svg_store_scaled(mp,-gr_txy_val(p)); append_char(',');
+ mp_svg_store_scaled(mp,gr_tyy_val(p)); append_char(',');
+ } else {
+ append_string("translate(");
+ }
+ mp_svg_pair_out(mp,gr_tx_val(p),gr_ty_val(p));
+ append_char(')');
+
+ mp_svg_attribute(mp, "transform", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+
+ append_string("fill: ");
+ mp_svg_color_out(mp,(mp_graphic_object *)p);
+ append_char(';');
+ mp_svg_attribute(mp, "style", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+
+ mp_svg_close_starttag(mp);
+
+ if (prologues == 3 ) {
+
+ scaled charwd;
+ double wd = 0.0; /* this is in PS design units */
+ while (l-->0) {
+ k=(int)*s++;
+ mp_svg_open_starttag(mp, "use");
+ append_string("#GLYPH");
+ append_string(mp->font_name[gr_font_n(p)]);
+ append_char('_');
+ mp_svg_store_int(mp,k);
+ mp_svg_attribute(mp,"xlink:href", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ charwd = scaled_from_double((wd/100));
+ if (charwd!=0) {
+ mp_svg_store_scaled(mp,charwd);
+ mp_svg_attribute(mp,"x", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ }
+ wd += mp_get_char_dimension (mp, mp->font_name[gr_font_n(p)], k, 'w');
+ mp_svg_close_starttag(mp);
+ mp_svg_endtag(mp, "use", false);
+ }
+ } else {
+ mp_svg_open_starttag(mp, "text");
+ ds=(mp->font_dsize[gr_font_n(p)]+8) / 16;
+ mp_svg_store_scaled(mp,ds);
+ mp_svg_attribute(mp, "font-size", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ mp_svg_close_starttag(mp);
+
+ while (l-->0) {
+ k=(int)*s++;
+ if (@<Character |k| is illegal in SVG output@>) {
+ char S[100];
+ mp_snprintf(S,99,"The character %d cannot be output in SVG "
+ "unless prologues:=3;",k);
+ mp_warn(mp,S);
+ } else if ( (@<Character |k| is not allowed in SVG output@>) ) {
+ append_string("&#");
+ mp_svg_store_int(mp,k);
+ append_char(';');
+ } else {
+ append_char(k);
+ }
+ }
+ mp_svg_print_buf(mp);
+ mp_svg_endtag(mp, "text", false);
+ }
+ mp_svg_endtag(mp, "g", true);
+}
+
+@ When stroking a path with an elliptical pen, it is necessary to transform
+the coordinate system so that a unit circular pen will have the desired shape.
+To keep this transformation local, we enclose it in a $$\&{<g>}\ldots\&{</g>}$$
+block. Any translation component must be applied to the path being stroked
+while the rest of the transformation must apply only to the pen.
+If |fill_also=true|, the path is to be filled as well as stroked so we must
+insert commands to do this after giving the path.
+
+@<Declarations@>=
+static void mp_svg_stroke_out (MP mp, mp_graphic_object *h,
+ mp_pen_info *pen, boolean fill_also) ;
+
+
+@ @c
+void mp_svg_stroke_out (MP mp, mp_graphic_object *h,
+ mp_pen_info *pen, boolean fill_also) {
+ boolean transformed = false;
+ if (pen != NULL) {
+ transformed = true;
+ if ((pen->sx==unity) &&
+ (pen->rx==0) &&
+ (pen->ry==0) &&
+ (pen->sy==unity) &&
+ (pen->tx==0) &&
+ (pen->ty==0)) {
+ transformed = false;
+ }
+ }
+ if (transformed) {
+ mp_svg_open_starttag(mp, "g");
+ append_string("matrix(");
+ mp_svg_store_scaled(mp,pen->sx); append_char(',');
+ mp_svg_store_scaled(mp,pen->rx); append_char(',');
+ mp_svg_store_scaled(mp,pen->ry); append_char(',');
+ mp_svg_store_scaled(mp,pen->sy); append_char(',');
+ mp_svg_store_scaled(mp,pen->tx); append_char(',');
+ mp_svg_store_scaled(mp,pen->ty);
+ append_char(')');
+ mp_svg_attribute(mp, "transform", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ mp_svg_close_starttag(mp);
+ }
+ mp_svg_open_starttag(mp, "path");
+
+ if (false) {
+ if (transformed)
+ mp_svg_path_trans_out(mp, gr_path_p((mp_fill_object *)h), pen);
+ else
+ mp_svg_path_out(mp, gr_path_p((mp_fill_object *)h));
+ mp_svg_attribute(mp, "d", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ append_string("fill: ");
+ mp_svg_color_out(mp,h);
+ append_string("; stroke: none;");
+ mp_svg_attribute(mp, "style", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ } else {
+ if (transformed)
+ mp_svg_path_trans_out(mp, gr_path_p((mp_stroked_object *)h), pen);
+ else
+ mp_svg_path_out(mp, gr_path_p((mp_stroked_object *)h));
+ mp_svg_attribute(mp, "d", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ append_string("stroke:");
+ mp_svg_color_out(mp,h);
+ append_string("; stroke-width: ");
+ if (pen != NULL) {
+ mp_svg_store_scaled(mp, pen->ww);
+ } else {
+ append_char('0');
+ }
+ append_char(';');
+ if (gr_lcap_val(h)!=0) {
+ append_string("stroke-linecap: ");
+ switch (gr_lcap_val(h)) {
+ case 1: append_string("round"); break;
+ case 2: append_string("square"); break;
+ default: append_string("butt"); break;
+ }
+ append_char(';');
+ }
+ if (gr_type(h)!=mp_fill_code) {
+ mp_dash_object *hh;
+ hh =gr_dash_p(h);
+ if (hh != NULL && hh->array != NULL) {
+ int i;
+ append_string("stroke-dasharray: ");
+ /* svg doesn't accept offsets */
+ for (i=0; *(hh->array+i) != -1;i++) {
+ mp_svg_store_scaled(mp, *(hh->array+i));
+ append_char(' ') ;
+ }
+ append_char(';');
+ }
+
+ if (gr_ljoin_val((mp_stroked_object *)h)!=0) {
+ append_string ("stroke-linejoin: ");
+ switch (gr_ljoin_val((mp_stroked_object *)h)) {
+ case 1: append_string("round"); break;
+ case 2: append_string("bevel"); break;
+ default: append_string("miter"); break;
+ }
+ append_char(';');
+ }
+
+ if (gr_miterlim_val((mp_stroked_object *)h) != 4*unity) {
+ append_string("stroke-miterlimit: ");
+ mp_svg_store_scaled(mp, gr_miterlim_val((mp_stroked_object *)h));
+ append_char(';');
+ }
+ }
+
+ append_string("fill: ");
+ if (fill_also) {
+ mp_svg_color_out(mp,h);
+ } else {
+ append_string("none");
+ }
+ append_char(';');
+ mp_svg_attribute(mp, "style", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ }
+ mp_svg_close_starttag(mp);
+ mp_svg_endtag(mp, "path", false);
+ if (transformed) {
+ mp_svg_endtag(mp, "g", true);
+ }
+}
+
+@ Here is a simple routine that just fills a cycle.
+
+@<Declarations@>=
+static void mp_svg_fill_out (MP mp, mp_knot *p, mp_graphic_object *h);
+
+@ @c
+void mp_svg_fill_out (MP mp, mp_knot *p, mp_graphic_object *h) {
+ mp_svg_open_starttag(mp, "path");
+ mp_svg_path_out(mp, p);
+ mp_svg_attribute(mp, "d", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ append_string("fill: ");
+ mp_svg_color_out(mp,h);
+ append_string(";stroke: none;");
+ mp_svg_attribute(mp, "style", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ mp_svg_close_starttag(mp); /* path */
+ mp_svg_endtag(mp, "path", false);
+}
+
+@ Clipping paths use IDs, so an extra global is needed:
+
+@<Globals...@>=
+int clipid;
+
+@
+@<Set initial values@>=
+mp->svg->clipid = 0;
+
+@ @<Declarations@>=
+static void mp_svg_clip_out (MP mp, mp_clip_object *p);
+
+@ @c
+void mp_svg_clip_out (MP mp, mp_clip_object *p) {
+ mp->svg->clipid++;
+ mp_svg_starttag(mp, "g");
+ mp_svg_starttag(mp, "defs");
+ mp_svg_open_starttag(mp, "clipPath");
+
+ append_string("CLIP");
+ mp_svg_store_int(mp, mp->svg->clipid);
+ mp_svg_attribute(mp, "id", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+
+ mp_svg_close_starttag(mp);
+ mp_svg_open_starttag(mp, "path");
+ mp_svg_path_out(mp, gr_path_p(p));
+ mp_svg_attribute(mp,"d", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+ mp_svg_attribute(mp, "style", "fill: black; stroke: none;");
+ mp_svg_close_starttag(mp); /* path */
+ mp_svg_endtag(mp, "path", false);
+ mp_svg_endtag(mp, "clipPath", true);
+ mp_svg_endtag(mp, "defs", true);
+ mp_svg_open_starttag(mp, "g");
+
+ append_string("url(#CLIP");
+ mp_svg_store_int(mp, mp->svg->clipid);
+ append_string(");");
+ mp_svg_attribute(mp, "clip-path", mp->svg->buf);
+ mp_svg_reset_buf(mp);
+
+ mp_svg_close_starttag(mp);
+}
+
+
+
+@ The main output function
+
+@d gr_has_scripts(A) (gr_type((A))<mp_start_clip_code)
+@d pen_is_elliptical(A) ((A)==gr_next_knot((A)))
+
+@<Exported function ...@>=
+int mp_svg_gr_ship_out (mp_edge_object *hh, int prologues, int standalone) ;
+
+@ @c
+int mp_svg_gr_ship_out (mp_edge_object *hh, int qprologues, int standalone) {
+ mp_graphic_object *p;
+ mp_pen_info *pen = NULL;
+ MP mp = hh->parent;
+ if (standalone) {
+ mp->jump_buf = malloc(sizeof(jmp_buf));
+ if (mp->jump_buf == NULL || setjmp(*(mp->jump_buf)))
+ return 0;
+ }
+ if (mp->history >= mp_fatal_error_stop ) return 1;
+ mp_open_output_file(mp);
+ if ( (qprologues>=1) && (mp->last_ps_fnum<mp->last_fnum) )
+ mp_read_psname_table(mp);
+ mp_svg_print_initial_comment(mp, hh);
+ if (qprologues == 3) {
+ mp_svg_print_glyph_defs(mp, hh);
+ }
+ p = hh->body;
+ while ( p!=NULL ) {
+ if ( gr_has_scripts(p) ) {
+ @<Write |pre_script| of |p|@>;
+ }
+ switch (gr_type(p)) {
+ case mp_fill_code:
+ {
+ mp_fill_object *ph = (mp_fill_object *)p;
+ if ( gr_pen_p(ph)==NULL ) {
+ mp_svg_fill_out(mp, gr_path_p(ph), p);
+ } else if ( pen_is_elliptical(gr_pen_p(ph)) ) {
+ pen = mp_svg_pen_info(mp, gr_path_p(ph), gr_pen_p(ph));
+ mp_svg_stroke_out(mp, p, pen, true);
+ mp_xfree(pen);
+ } else {
+ mp_svg_fill_out(mp, gr_path_p(ph), p);
+ mp_svg_fill_out(mp, gr_htap_p(ph), p);
+ }
+ }
+ break;
+ case mp_stroked_code:
+ {
+ mp_stroked_object *ph = (mp_stroked_object *)p;
+ if ( pen_is_elliptical(gr_pen_p(ph))) {
+ pen = mp_svg_pen_info(mp, gr_path_p(ph), gr_pen_p(ph));
+ mp_svg_stroke_out(mp, p, pen, false);
+ mp_xfree(pen);
+ } else {
+ mp_svg_fill_out(mp, gr_path_p(ph), p);
+ }
+ }
+ break;
+ case mp_text_code:
+ if ( (gr_font_n(p)!=null_font) && (gr_text_l(p)>0) ) {
+ mp_svg_text_out(mp, (mp_text_object *)p, qprologues);
+ }
+ break;
+ case mp_start_clip_code:
+ mp_svg_clip_out(mp, (mp_clip_object *)p);
+ break;
+ case mp_stop_clip_code:
+ mp_svg_endtag(mp, "g", true);
+ mp_svg_endtag(mp, "g", true);
+ break;
+ case mp_start_bounds_code:
+ case mp_stop_bounds_code:
+ break;
+ case mp_special_code:
+ {
+ mp_special_object *ps = (mp_special_object *)p;
+ mp_svg_print_nl (mp, gr_pre_script(ps));
+ mp_svg_print_ln (mp);
+ }
+ break;
+ } /* all cases are enumerated */
+ if ( gr_has_scripts(p) ) {
+ @<Write |post_script| of |p|@>;
+ }
+ p=gr_link(p);
+ }
+ mp_svg_endtag(mp, "svg", true);
+ mp_svg_print_ln(mp);
+ (mp->close_file)(mp,mp->output_file);
+ return 1;
+}
+
+@ @(mplibsvg.h@>=
+int mp_svg_ship_out (mp_edge_object *hh, int prologues) ;
+
+@ @c
+int mp_svg_ship_out (mp_edge_object *hh, int prologues) {
+ return mp_svg_gr_ship_out (hh, prologues, (int)true);
+}
+
+@
+@d do_write_prescript(a,b) {
+ if ( (gr_pre_script((b *)a))!=NULL ) {
+ mp_svg_print_nl (mp, gr_pre_script((b *)a));
+ mp_svg_print_ln(mp);
+ }
+}
+
+@<Write |pre_script| of |p|@>=
+{
+ if (gr_type(p)==mp_fill_code) { do_write_prescript(p,mp_fill_object); }
+ else if (gr_type(p)==mp_stroked_code) { do_write_prescript(p,mp_stroked_object); }
+ else if (gr_type(p)==mp_text_code) { do_write_prescript(p,mp_text_object); }
+}
+
+
+@
+@d do_write_postscript(a,b) {
+ if ( (gr_post_script((b *)a))!=NULL ) {
+ mp_svg_print_nl (mp, gr_post_script((b *)a));
+ mp_svg_print_ln(mp);
+ }
+}
+
+@<Write |post_script| of |p|@>=
+{
+ if (gr_type(p)==mp_fill_code) { do_write_postscript(p,mp_fill_object); }
+ else if (gr_type(p)==mp_stroked_code) { do_write_postscript(p,mp_stroked_object); }
+ else if (gr_type(p)==mp_text_code) { do_write_postscript(p,mp_text_object); }
+}
diff --git a/Build/source/texk/web2c/mplibdir/tfmin.w b/Build/source/texk/web2c/mplibdir/tfmin.w
new file mode 100644
index 00000000000..d6361d767e7
--- /dev/null
+++ b/Build/source/texk/web2c/mplibdir/tfmin.w
@@ -0,0 +1,242 @@
+% $Id: mp.w 597 2008-07-03 15:35:34Z taco $
+%
+% Copyright 2008 Taco Hoekwater.
+%
+% This program is free software: you can redistribute it and/or modify
+% it under the terms of the GNU Lesser General Public License as published by
+% the Free Software Foundation, either version 3 of the License, or
+% (at your option) any later version.
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+% GNU Lesser General Public License for more details.
+%
+% You should have received a copy of the GNU Lesser General Public License
+% along with this program. If not, see <http://www.gnu.org/licenses/>.
+%
+% TeX is a trademark of the American Mathematical Society.
+% METAFONT is a trademark of Addison-Wesley Publishing Company.
+% PostScript is a trademark of Adobe Systems Incorporated.
+
+% Here is TeX material that gets inserted after \input webmac
+
+\font\tenlogo=logo10 % font used for the METAFONT logo
+\font\logos=logosl10
+\def\MF{{\tenlogo META}\-{\tenlogo FONT}}
+\def\MP{{\tenlogo META}\-{\tenlogo POST}}
+
+\def\title{Reading TEX metrics files}
+\pdfoutput=1
+
+@ Introduction.
+
+@ Needed headers and macros
+
+@d qi(A) (quarterword)(A) /* to store eight bits in a quarterword */
+@d null_font 0 /* the |font_number| for an empty font */
+@d false 0
+@d true 1
+@d hlp1(A) mp->help_line[0]=A; }
+@d hlp2(A,B) mp->help_line[1]=A; hlp1(B)
+@d hlp3(A,B,C) mp->help_line[2]=A; hlp2(B,C)
+@d help3 { mp->help_ptr=3; hlp3 /* use this with three help lines */
+
+@c
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "mplib.h"
+#include "mpmp.h" /* internal header */
+@h
+
+@ The |font_ps_name| for a built-in font should be what PostScript expects.
+A preliminary name is obtained here from the \.{TFM} name as given in the
+|fname| argument. This gets updated later from an external table if necessary.
+
+@c
+font_number mp_read_font_info (MP mp, char *fname) {
+ boolean file_opened; /* has |tfm_infile| been opened? */
+ font_number n; /* the number to return */
+ halfword lf,tfm_lh,bc,ec,nw,nh,nd; /* subfile size parameters */
+ size_t whd_size; /* words needed for heights, widths, and depths */
+ int i,ii; /* |font_info| indices */
+ int jj; /* counts bytes to be ignored */
+ scaled z; /* used to compute the design size */
+ fraction d; /* height, width, or depth as a fraction of design size times $2^{-8}$ */
+ int h_and_d; /* height and depth indices being unpacked */
+ int tfbyte = 0; /* a byte read from the file */
+ n=null_font;
+ @<Open |tfm_infile| for input@>;
+ @<Read data from |tfm_infile|; if there is no room, say so and |goto done|;
+ otherwise |goto bad_tfm| or |goto done| as appropriate@>;
+BAD_TFM:
+ @<Complain that the \.{TFM} file is bad@>;
+DONE:
+ if ( file_opened ) (mp->close_file)(mp,mp->tfm_infile);
+ if ( n!=null_font ) {
+ mp->font_ps_name[n]=mp_xstrdup(mp,fname);
+ mp->font_name[n]=mp_xstrdup(mp,fname);
+ }
+ return n;
+}
+
+@ \MP\ doesn't bother to check the entire \.{TFM} file for errors or explain
+precisely what is wrong if it does find a problem. Programs called \.{TFtoPL}
+@.TFtoPL@> @.PLtoTF@>
+and \.{PLtoTF} can be used to debug \.{TFM} files.
+
+@<Complain that the \.{TFM} file is bad@>=
+mp_print_err(mp,"Font ");
+mp_print(mp, fname);
+if ( file_opened ) mp_print(mp, " not usable: TFM file is bad");
+else mp_print(mp, " not usable: TFM file not found");
+help3("I wasn't able to read the size data for this font so this",
+ "`infont' operation won't produce anything. If the font name",
+ "is right, you might ask an expert to make a TFM file");
+if ( file_opened )
+ mp->help_line[0]="is right, try asking an expert to fix the TFM file";
+mp_error(mp)
+
+@ @<Read data from |tfm_infile|; if there is no room, say so...@>=
+@<Read the \.{TFM} size fields@>;
+@<Use the size fields to allocate space in |font_info|@>;
+@<Read the \.{TFM} header@>;
+@<Read the character data and the width, height, and depth tables and
+ |goto done|@>
+
+@ A bad \.{TFM} file can be shorter than it claims to be. The code given here
+might try to read past the end of the file if this happens. Changes will be
+needed if it causes a system error to refer to |tfm_infile^| or call
+|get_tfm_infile| when |eof(tfm_infile)| is true. For example, the definition
+@^system dependencies@>
+of |tfget| could be changed to
+``|begin get(tfm_infile); if eof(tfm_infile) then goto bad_tfm; end|.''
+
+@d tfget do {
+ size_t wanted=1;
+ unsigned char abyte=0;
+ void *tfbyte_ptr = &abyte;
+ (mp->read_binary_file)(mp,mp->tfm_infile, &tfbyte_ptr,&wanted);
+ if (wanted==0) goto BAD_TFM;
+ tfbyte = (int)abyte;
+} while (0)
+@d read_two(A) { (A)=tfbyte;
+ if ( (A)>127 ) goto BAD_TFM;
+ tfget; (A)=(A)*0400+tfbyte;
+}
+@d tf_ignore(A) { for (jj=(A);jj>=1;jj--) tfget; }
+
+@<Read the \.{TFM} size fields@>=
+tfget; read_two(lf);
+tfget; read_two(tfm_lh);
+tfget; read_two(bc);
+tfget; read_two(ec);
+if ( (bc>1+ec)||(ec>255) ) goto BAD_TFM;
+tfget; read_two(nw);
+tfget; read_two(nh);
+tfget; read_two(nd);
+whd_size=(size_t)((ec+1-bc)+nw+nh+nd);
+if ( lf<(int)(6+tfm_lh+whd_size) ) goto BAD_TFM;
+tf_ignore(10)
+
+@ Offsets are added to |char_base[n]| and |width_base[n]| so that is not
+necessary to apply the |so| and |qo| macros when looking up the width of a
+character in the string pool. In order to ensure nonnegative |char_base|
+values when |bc>0|, it may be necessary to reserve a few unused |font_info|
+elements.
+
+@<Use the size fields to allocate space in |font_info|@>=
+if ( mp->next_fmem<(size_t)bc)
+ mp->next_fmem=(size_t)bc; /* ensure nonnegative |char_base| */
+if (mp->last_fnum==mp->font_max)
+ mp_reallocate_fonts(mp,(mp->font_max+(mp->font_max/4)));
+while (mp->next_fmem+whd_size>=mp->font_mem_size) {
+ size_t l = mp->font_mem_size+(mp->font_mem_size/4);
+ memory_word *font_info;
+ font_info = mp_xmalloc (mp,(l+1),sizeof(memory_word));
+ memset (font_info,0,sizeof(memory_word)*(l+1));
+ memcpy (font_info,mp->font_info,sizeof(memory_word)*(mp->font_mem_size+1));
+ mp_xfree(mp->font_info);
+ mp->font_info = font_info;
+ mp->font_mem_size = l;
+}
+mp->last_fnum++;
+n=mp->last_fnum;
+mp->font_bc[n]=(eight_bits)bc;
+mp->font_ec[n]=(eight_bits)ec;
+mp->char_base[n]=(int)(mp->next_fmem-bc);
+mp->width_base[n]=(int)(mp->next_fmem+ec-bc+1);
+mp->height_base[n]=mp->width_base[n]+nw;
+mp->depth_base[n]=mp->height_base[n]+nh;
+mp->next_fmem=mp->next_fmem+whd_size;
+
+
+@ @<Read the \.{TFM} header@>=
+if ( tfm_lh<2 ) goto BAD_TFM;
+tf_ignore(4);
+tfget; read_two(z);
+tfget; z=z*0400+tfbyte;
+tfget; z=z*0400+tfbyte; /* now |z| is 16 times the design size */
+mp->font_dsize[n]=mp_take_fraction(mp, z,267432584);
+ /* times ${72\over72.27}2^{28}$ to convert from \TeX\ points */
+tf_ignore(4*(tfm_lh-2))
+
+@ @<Read the character data and the width, height, and depth tables...@>=
+ii=mp->width_base[n];
+i=mp->char_base[n]+bc;
+while ( i<ii ) {
+ tfget; mp->font_info[i].qqqq.b0=qi(tfbyte);
+ tfget; h_and_d=tfbyte;
+ mp->font_info[i].qqqq.b1=qi(h_and_d / 16);
+ mp->font_info[i].qqqq.b2=qi(h_and_d % 16);
+ tfget; tfget;
+ i++;
+}
+while ( i<(int)mp->next_fmem ) {
+ @<Read a four byte dimension, scale it by the design size, store it in
+ |font_info[i]|, and increment |i|@>;
+}
+goto DONE
+
+@ The raw dimension read into |d| should have magnitude at most $2^{24}$ when
+interpreted as an integer, and this includes a scale factor of $2^{20}$. Thus
+we can multiply it by sixteen and think of it as a |fraction| that has been
+divided by sixteen. This cancels the extra scale factor contained in
+|font_dsize[n|.
+
+@<Read a four byte dimension, scale it by the design size, store it in...@>=
+{
+tfget; d=tfbyte;
+if ( d>=0200 ) d=d-0400;
+tfget; d=d*0400+tfbyte;
+tfget; d=d*0400+tfbyte;
+tfget; d=d*0400+tfbyte;
+mp->font_info[i].cint=mp_take_fraction(mp, d*16,mp->font_dsize[n]);
+i++;
+}
+
+@ This function does no longer use the file name parser, because |fname| is
+a C string already.
+
+@<Open |tfm_infile| for input@>=
+file_opened=false;
+mp_ptr_scan_file(mp, fname);
+if ( strlen(mp->cur_area)==0 ) { mp_xfree(mp->cur_area); mp->cur_area=NULL; }
+if ( strlen(mp->cur_ext)==0 ) {
+ mp_xfree(mp->cur_ext);
+ mp->cur_ext=mp_xstrdup(mp,".tfm");
+}
+mp_pack_file_name(mp, mp->cur_name,mp->cur_area,mp->cur_ext);
+mp->tfm_infile = (mp->open_file)(mp, mp->name_of_file, "r",mp_filetype_metrics);
+if ( !mp->tfm_infile ) goto BAD_TFM;
+file_opened=true
+
+
+
+
+
+
+
+