texk 1

git-svn-id: svn://tug.org/texlive/trunk@1485 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 1090 insertions, 0 deletions

diff --git a/Build/source/texk/xdvik/psgs.c b/Build/source/texk/xdvik/psgs.c
new file mode 100644
index 00000000000..e0d902848a4
--- /dev/null
+++ b/Build/source/texk/xdvik/psgs.c
@@ -0,0 +1,1090 @@
+/*========================================================================*\
+
+Copyright (c) 1994-2004  Paul Vojta
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to
+deal in the Software without restriction, including without limitation the
+rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+PAUL VOJTA OR ANY OTHER AUTHOR OF THIS SOFTWARE BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+\*========================================================================*/
+
+#ifdef PS_GS	/* entire file */
+
+
+#include <setjmp.h>
+#include <X11/Xatom.h>
+#include <sys/time.h>	/* for timeval */
+
+#include <signal.h>
+
+/* Condition for retrying a write */
+#include <errno.h>
+
+#include "xdvi-config.h"
+#include "xdvi.h"
+#include "psgs.h"
+
+#include "kpathsea/c-pathmx.h"
+#include "dvi-init.h"
+#include "dvi-draw.h"
+#include "events.h"
+#include "statusline.h"
+#include "special.h"
+#include "util.h"
+
+
+#ifdef	X_NOT_STDC_ENV
+extern	int	errno;
+#endif
+
+#ifdef	EWOULDBLOCK
+# ifdef	EAGAIN
+#  define AGAIN_CONDITION	(errno == EWOULDBLOCK || errno == EAGAIN)
+# else
+#  define AGAIN_CONDITION	(errno == EWOULDBLOCK)
+# endif
+#else
+# ifdef	EAGAIN
+#  define AGAIN_CONDITION	(errno == EAGAIN)
+# endif
+#endif
+
+#if HAVE_POLL
+# include <poll.h>
+# define XIO_IN POLLIN
+# define XIO_OUT POLLOUT
+#else
+# define XIO_IN 1
+# define XIO_OUT 2
+#endif
+
+#ifdef MOTIF
+# include <Xm/Xm.h>
+#endif
+
+extern const char psheader[];
+extern unsigned psheaderlen;
+
+Boolean gs_postpone_prescan = False;
+
+/* global procedures (besides initGS) */
+
+static void toggle_gs(int flag);
+static void destroy_gs(void);
+static void interrupt_gs(void);
+static void endpage_gs(void);
+static void drawbegin_gs(int, int, const char *);
+static void drawbegin_gs_box(int, int, const char *);
+void drawraw_gs(const char *);
+static void drawfile_gs(const char *, FILE *);
+static void drawend_gs(const char *);
+static void beginheader_gs(void);
+static void endheader_gs(void);
+static void newdoc_gs(void);
+
+static struct psprocs gs_procs = {
+    /* toggle */ toggle_gs,
+    /* destroy */ destroy_gs,
+    /* interrupt */ interrupt_gs,
+    /* endpage */ endpage_gs,
+    /* drawbegin */ drawbegin_gs,
+    /* drawraw */ drawraw_gs,
+    /* drawfile */ drawfile_gs,
+    /* drawend */ drawend_gs,
+    /* beginheader */ beginheader_gs,
+    /* endheader */ endheader_gs,
+    /* newdoc */ newdoc_gs
+};
+
+static int std_io[2];
+Pixmap bpixmap;
+
+#define	GS_fd	(std_io[0])
+
+		/* some arguments are filled in later */
+static char arg4[] = "-dDEVICEWIDTH=xxxxxxxxxx";
+static char arg5[] = "-dDEVICEHEIGHT=xxxxxxxxxx";
+
+static const char *argv[] = {
+    NULL, NULL, "-dNOPAUSE", "-q", arg4, arg5,
+    "-dDEVICEXRESOLUTION=72",
+    "-dDEVICEYRESOLUTION=72",
+    "-dNOSAFER", "-dNOEPS", NULL, NULL, NULL, NULL, NULL, NULL
+};
+
+static unsigned int GS_page_w;	/* how big our current page is */
+static unsigned int GS_page_h;
+static Boolean GS_alpha;	/* remember if we are using the alpha driver */
+static unsigned long GS_mag;	/* magnification currently in use */
+static int GS_shrink;		/* shrink factor currently in use */
+static Boolean GS_active;	/* if we've started a page yet */
+static int GS_pending;		/* number of ack's we're expecting */
+static char GS_outb[257];	/* circular output buffer */
+static char *GS_outb_in;	/* next position in output buffer */
+static char *GS_outb_out;	/* next byte to come out of buffer */
+#define	GS_outb_limit	(GS_outb + sizeof GS_outb)	/* last+1 byte */
+static int GS_write_ack;	/* flag to set when done writing */
+static Boolean GS_in_header;	/* if we're sending a header */
+static Boolean GS_in_doc;	/* if we've sent header information */
+static int GS_ev_mask;		/* events for which we'll stop */
+static int GS_die_ack = 0;	/* flags to set when GS dies */
+static Boolean GS_timer_set;	/* if there's a timer set */
+static Boolean GS_old;		/* if we're using gs 2.xx */
+
+#define	GS_MASK_NORMAL	EV_GE_NEWPAGE
+#define	GS_MASK_HEADER	EV_GE_PS_TOGGLE
+#define	GS_MASK_INIT	(EV_GE_TERM | EV_PS_TOGGLE)
+
+static Atom gs_atom;
+static Atom gs_colors_atom;
+
+#define	Landscape	90
+
+#define	LINELEN	81
+static char line[LINELEN + 1];
+static char *linepos = line;
+static char ackstr[] = "\347\310\376";
+static char oldstr[] = "\347\310\375";
+
+static void gs_died(int, struct xchild *);
+
+static char *read_from_gs(int);
+static void write_to_gs(int);
+
+static	struct xio	gs_xio		= {NULL, 0, XIO_IN,
+#if HAVE_POLL
+    NULL,
+#endif
+    read_from_gs, write_to_gs
+};
+
+static struct xchild gs_child = { NULL, 0, True, NULL, NULL, NULL, gs_died };
+#define	GS_pid		(gs_child.pid)
+
+/* It seems that XtTimers don't work reliably with xdvi's event treatment;
+   so use custom timers for the time being. Search for TIMER_PROBLEM_FIXED
+   to locate the relevant code parts.
+*/
+
+#if TIMER_PROBLEM_FIXED
+static XtIntervalId gs_timeout_id = 0;
+static void gs_timer_proc(XtPointer client_data, XtIntervalId * id);
+static	struct xtimer	gs_timer	= {NULL, {0, 0}, gs_timer_proc};
+#else
+static void gs_alarm(struct xtimer *timer);
+static struct xtimer gs_timer = {NULL, {0, 0}, XTM_DEFAULT, gs_alarm
+#if XDVI_XT_TIMER_HACK
+				    , NULL, NULL
+#endif
+};
+#endif
+
+
+static void
+showto(char *q)
+{
+    char *p = line;
+    char *p1;
+
+    while (p < q) {
+	p1 = memchr(p, '\n', q - p);
+	if (p1 == NULL)
+	    p1 = q;
+	*p1 = '\0';
+	printf("gs: %s\n", p);
+	p = p1 + 1;
+    }
+}
+
+static char *
+read_from_gs(int fd)
+{
+    int bytes;
+    char *line_end = NULL;
+    char *p;
+
+    for (;;) {
+
+	bytes = read(fd, linepos, line + LINELEN - linepos);
+	if (bytes < 0) {
+	    if (AGAIN_CONDITION)
+		break;
+	    perror("xdvik: read_from_gs");
+	    break;
+	}
+	line_end = linepos + bytes;
+
+	if (bytes == 0) {
+	    if (GS_pid != 0)
+		XDVI_WARNING((stderr, "Read_from_gs returned 0 bytes"));
+	    break;
+	}
+
+	/* Check for ack strings */
+	for (p = line; p < line_end - 2; ++p) {
+	    p = memchr(p, '\347', line_end - p - 2);
+	    if (p == NULL) break;
+	    if (memcmp(p, ackstr, 3) == 0) {
+		--GS_pending;
+		if (GS_pending == 0)
+		    globals.ev.flags |= EV_ACK;
+		if (globals.debug & DBG_PS)
+		    printf("Got GS ack; %d pending.\n", GS_pending);
+	    } else if (memcmp(p, oldstr, 3) == 0) {
+		if (globals.debug & DBG_PS)
+		    puts("Using old GS version.");
+		GS_old = True;
+	    } else
+		continue;
+
+	    showto(p);
+	    p += 3;
+	    memmove(line, p, line_end - p);
+	    line_end -= p - line;
+	    linepos = p = line;
+	    --p;
+	}
+	*line_end = '\0';
+	p = rindex(linepos, '\n');
+	if (p != NULL) {
+	    ++p;
+	    showto(p);
+	    memmove(line, p, line_end - p);
+	    line_end -= p - line;
+	}
+	linepos = line_end;
+	/*
+	 * Normally we'd hold text until a newline character, but the
+	 * buffer is full.  So we flush it, being careful not to cut up an
+	 * ack string.
+	 */
+	if (linepos >= line + LINELEN) {
+	    p = line + LINELEN;
+	    if ((*--p != '\347' && *--p != '\347' && *--p != '\347')
+		    || (memcmp(p, ackstr, line + LINELEN - p) != 0
+			&& memcmp(p, oldstr, line + LINELEN - p) != 0))
+		p = line + LINELEN;
+	    *p = '\0';
+	    printf("gs: %s\n", line);
+	    *p = '\347';
+	    linepos = line;
+	    while (p < line + LINELEN)
+		*linepos++ = *p++;
+	}
+    }
+    return line_end; /* dummy */
+}
+
+static void
+write_to_gs(int fd)
+{
+    char *send_end;
+    int	bytes;
+
+    UNUSED(fd);
+    
+    for (;;) {
+	send_end = GS_outb_in;
+	if (send_end < GS_outb_out)
+	    send_end = GS_outb_limit;
+	bytes = write(GS_fd, GS_outb_out, send_end - GS_outb_out);
+
+	if (bytes < 0) {
+	    if (AGAIN_CONDITION)
+		break;
+	    perror("xdvik: write_to_gs");
+	    break;
+	}
+
+	GS_outb_out += bytes;
+	if (GS_outb_out == GS_outb_limit)
+	    GS_outb_out = GS_outb;
+	if (GS_outb_out == GS_outb_in) {	/* if buffer is empty */
+	    gs_xio.xio_events = XIO_IN;
+#if HAVE_POLL
+	    if (gs_xio.pfd != NULL)	/* write_to_gs is called directly */
+		gs_xio.pfd->events = XIO_IN;
+#endif
+	    break;
+	}
+    }
+    globals.ev.flags |= GS_write_ack;
+    GS_write_ack = 0;
+}
+
+/*
+ *	Main routine for writing to the GS interpreter.
+ */
+
+static void
+gs_send(const char *cp, size_t len)
+{
+    const char *cp_end = cp + len;
+    char *send_end;
+    size_t bytes;
+    char *old_out;
+    Boolean interrupting;
+
+    if (GS_pid == 0 || (globals.ev.flags & GS_ev_mask))
+	return;
+
+    /*
+     * Because cp might reside on the stack, don't return until we've
+     * copied all of it to our circular output buffer.
+     * Note that GS_outb_out == GS_outb_in means that the buffer is empty.
+     */
+
+    GS_timer_set = interrupting = False;
+    for (;;) {
+	send_end = GS_outb_out;
+	if (send_end == GS_outb)
+	    send_end = GS_outb_limit;
+	--send_end;
+	if (send_end < GS_outb_in)
+	    send_end = GS_outb_limit;
+	bytes = send_end - GS_outb_in;
+	if (bytes > 0) {
+	    if (bytes >= (unsigned)(cp_end - cp))
+		bytes = cp_end - cp;
+	    memcpy(GS_outb_in, cp, bytes);
+	    cp += bytes;
+	    GS_outb_in += bytes;
+	    if (GS_outb_in == GS_outb_limit)
+		GS_outb_in = GS_outb;
+	    if (cp < cp_end)
+		continue;
+	}
+
+	/* The buffer is now full --or-- we've run out of data */
+	old_out = GS_outb_out;
+	if (!(gs_xio.xio_events & XIO_OUT)) {	/* restart output */
+	    gs_xio.xio_events = XIO_IN | XIO_OUT;
+#if HAVE_POLL
+	    if (gs_xio.pfd != NULL)
+		gs_xio.pfd->events = POLLIN | POLLOUT;
+#endif
+	    write_to_gs(GS_fd);
+	    if (GS_outb_out != old_out) {
+		if (cp == cp_end)
+		    break;
+		else
+		    continue;
+	    }
+	}
+
+	if (cp == cp_end)
+	    break;
+
+	GS_die_ack = GS_write_ack = EV_ACK;
+	for (;;) {	/* loop because there may be stray ACKs */
+	    if (!interrupting) {
+		(void) read_events(GS_ev_mask | EV_ACK);
+		globals.ev.flags &= ~EV_ACK;
+
+		if (GS_pid == 0) {	/* if GS died */
+		    GS_die_ack = 0;
+		    return;
+		}
+		
+		if (GS_outb_out != old_out)	/* if more room in buffer */
+		    break;
+
+		if (globals.ev.flags & GS_ev_mask) {	/* if a serious event */
+		    if (globals.debug & DBG_PS)
+			puts("Setting timeout in gs_send()");
+
+		    set_timer(&gs_timer, resource.gs_timeout);
+		    GS_timer_set = interrupting = True;
+		}
+	    }
+	    else {
+		(void) read_events(EV_GE_TERM | EV_PS_TOGGLE | EV_ACK);
+		globals.ev.flags &= ~EV_ACK;
+
+		if (GS_outb_out != old_out)	/* if more room in buffer */
+		    break;
+
+		if (GS_timer_set)	/* if timer still set */
+		    cancel_timer(&gs_timer);
+
+		destroy_gs();
+		GS_die_ack = 0;
+		return;
+	    }
+	}
+    }
+
+    if (GS_timer_set)	/* if timer still set */
+	cancel_timer(&gs_timer);
+
+    GS_die_ack = GS_write_ack = 0;
+}
+
+static void
+#if TIMER_PROBLEM_FIXED
+gs_timer_proc(XtPointer client_data, XtIntervalId * id)
+#else
+gs_alarm(struct xtimer *timer)
+#endif
+{
+    UNUSED(timer);
+    
+    if (globals.debug & DBG_PS)
+	puts("GS timeout expired");
+
+    globals.ev.flags |= EV_ACK;
+    GS_timer_set = False;
+#if TIMER_PROBLEM_FIXED
+    gs_timeout_id = 0;
+#endif
+}
+
+/*
+ *	Wait for acknowledgement from GS.
+ */
+
+static	void
+waitack(void)
+{
+    if (GS_pending == 0) {
+	globals.ev.flags &= ~EV_ACK;
+	return;
+    }
+
+    GS_die_ack = EV_ACK;
+    
+    for (;;) {	/* loop because there might be stray ACKs. */
+/*  	fprintf(stderr, "looping for stray ACKs, page %d\n", current_page); */
+	(void) read_events(EV_GE_ACK);
+	globals.ev.flags &= ~EV_ACK;
+
+	if (GS_pending == 0) {
+	    GS_die_ack = 0;
+	    return;
+	}
+	if (globals.ev.flags & EV_GE_ACK)
+	    break;
+    }
+
+    if (globals.debug & DBG_PS)
+	puts("Setting timeout in waitack()");
+
+#if TIMER_PROBLEM_FIXED
+    if (gs_timeout_id)
+	XtRemoveTimeOut(gs_timeout_id);
+    gs_timeout_id = XtAppAddTimeOut(app, resource.gs_timeout,
+				    gs_timer_proc, (XtPointer) NULL);
+#else
+    set_timer(&gs_timer, resource.gs_timeout);
+#endif
+    GS_timer_set = True;
+
+    (void) read_events(EV_GE_TERM | EV_PS_TOGGLE | EV_ACK);
+    globals.ev.flags &= ~EV_ACK;
+
+    if (GS_timer_set) {
+#if TIMER_PROBLEM_FIXED
+	XtRemoveTimeOut(gs_timeout_id);
+	gs_timeout_id = 0;
+#else
+	cancel_timer(&gs_timer);
+#endif
+    }
+    GS_die_ack = 0;
+
+    if (GS_pending > 0)
+	destroy_gs();
+}
+
+
+/*
+ *	Fork a process to run ghostscript.  This is done using the
+ *	x11 device (which needs to be compiled in).  Normally the x11
+ *	device uses ClientMessage events to communicate with the calling
+ *	program, but we don't do this.  The reason for using the ClientMessage
+ *	events is that otherwise ghostview doesn't know when a non-conforming
+ *	postscript program calls showpage.   That doesn't affect us here,
+ *	since in fact we disable showpage.
+ *
+ *	SAFER mode is handled by providing both the -dNOSAFER and -dSAFER
+ *	options. Ghostscript versions 7.04 and earlier ignore -dNOSAFER and use
+ *	-dSAFER; the code in strsafe is ignored since .locksafe is not present.
+ *	In versions 7.04 and higher, -dNOSAFER overrides -dSAFER; SAFER mode is
+ *	optionally turned on by sending the strsafe string.  It is possible in some
+ *	versions of gs prior to 7.04 to use -dDELAYSAFER instead of -dNOSAFER, but
+ *	there's no point in doing that since .locksafe is not defined in those
+ *	versions.  I don't know where 7.03 fits in on all of this (but it works with
+ *	that version as well).
+ */
+
+Boolean
+initGS(void)
+{
+    char buf[100];
+    static Boolean did_putenv = False;
+    /*
+     * This string reads chunks (delimited by %%xdvimark).
+     * The first character of a chunk tells whether a given chunk
+     * is to be done within save/restore or not.
+     * The `H' at the end tells it that the first group is a
+     * header; i.e., no save/restore.
+     * `execute' is unique to ghostscript.
+     */
+
+    static const char strsafe[] =
+	"{ << /PermitFileReading [ (*) ] /PermitFileWriting [ ] /PermitFileControl [ ] "
+	">> setuserparams .locksafe "
+	"} stopped pop\n";
+    static const char str1[] =
+	"/xdvi$run {$error /newerror false put {currentfile cvx execute} stopped pop} "
+	"def "
+	"/xdvi$ack (\347\310\376) def "
+	"/xdvi$dslen countdictstack def "
+	"{currentfile read pop 72 eq "
+	"{xdvi$run} "
+	"{/xdvi$sav save def xdvi$run "
+	"clear countdictstack xdvi$dslen sub {end} repeat xdvi$sav restore} "
+	"ifelse "
+	"{(%%xdvimark) currentfile =string {readline} stopped "
+	"{clear} {pop eq {exit} if} ifelse }loop "
+	"flushpage xdvi$ack print flush "
+	"}loop\nH";
+    
+    static const char str2[] =
+	"[0 1 1 0 0 0] concat\n"
+	"revision 300 lt{(\347\310\375) print flush}if\n"
+	"stop\n%%xdvimark\n";
+    
+    /*
+      * If we're prescanning *before* setting up the widgets (to get the
+      * page size, for example), then postpone starting up ghostscript.
+      */
+    if (mane.win == (Window)0) {
+	if (globals.debug & DBG_PS)
+	    puts("Hit PS header in early prescan; postponing.");
+	psp = no_ps_procs;
+	gs_postpone_prescan = True;
+	return True;
+    }
+    
+    if (globals.debug & DBG_PS)
+	puts("Running initGS ...");
+    
+    gs_atom = XInternAtom(DISP, "GHOSTVIEW", False);
+    /* send bpixmap, orientation, bbox (in pixels), and h & v resolution */
+    sprintf(buf, "%ld %d 0 0 %u %u 72 72",
+	    bpixmap,		/* bpixmap */
+	    Landscape,	/* orientation */
+	    GS_page_h = globals.page.h, GS_page_w = globals.page.w);
+
+    XChangeProperty(DISP, mane.win, gs_atom, XA_STRING, 8,
+		    PropModeReplace, (unsigned char *)buf, strlen(buf));
+    GS_alpha = resource.gs_alpha;
+
+    gs_colors_atom = XInternAtom(DISP, "GHOSTVIEW_COLORS", False);
+    sprintf(buf, "%s %ld %ld", resource.gs_palette,
+	    color_data[0].pixel, color_data[1].pixel);
+    
+    XChangeProperty(DISP, mane.win, gs_colors_atom, XA_STRING, 8,
+		    PropModeReplace, (unsigned char *)buf, strlen(buf));
+
+    if (!did_putenv) {
+	sprintf(buf, "%ld", mane.win);
+	xputenv("GHOSTVIEW", buf);
+	did_putenv = True;
+    }
+
+    XSync(DISP, False);	/* update the window */
+
+    if (xpipe(std_io) != 0) {
+	perror("[xdvik] pipe");
+	return False;
+    }
+    fflush(stderr);	/* to avoid double flushing */
+    GS_pid = vfork();
+    if (GS_pid == 0) {	/* child */
+	const char **argvp = argv + 10;
+
+	argv[1] = resource.gs_alpha ? "-sDEVICE=x11alpha" : "-sDEVICE=x11";
+	sprintf(arg4 + 14, "%u", GS_page_w);
+	sprintf(arg5 + 15, "%u", GS_page_h);
+	if (resource.gs_safer)
+	    *argvp++ = "-dSAFER";
+
+#if 0
+	if (resource.gs_alpha) {
+	    *argvp++ = "-dGraphicsAlphaBits=4";
+	    *argvp++ = "-dTextAlphaBits=4";
+	    *argvp++ = "-dMaxBitmap=0";
+	}
+#endif
+	
+	*argvp = "-";
+	(void) close(std_io[0]);
+	(void) dup2(std_io[1], 0);
+	(void) dup2(std_io[1], 1);
+	(void) dup2(std_io[1], 2);
+	(void) close(std_io[1]);
+
+	(void)execvp(argv[0] = resource.gs_path, (char *const *)argv);
+	/*TODO: use fork_process here?? */
+	XDVI_ERROR((stderr, "Execvp of %s failed: %s", argv[0], strerror(errno)));
+	_exit(EXIT_FAILURE);
+    }
+
+    (void)close(std_io[1]);
+
+    if (GS_pid == -1) {	/* error */
+	GS_pid = 0;
+	perror("[xdvik] vfork");
+	(void)close(GS_fd);
+
+	return False;
+    }
+
+    prep_fd(GS_fd, True);	/* Set file descriptor for non-blocking I/O */
+
+    gs_child.name = xstrdup("gs");
+    gs_child.io = &gs_xio;
+    set_chld(&gs_child);
+
+    psp = gs_procs;
+    GS_active = False;
+    GS_in_header = True;
+    GS_pending = 1;
+    GS_mag = GS_shrink = -1;
+    gs_xio.fd = GS_fd;
+    gs_xio.xio_events = XIO_IN;
+    GS_write_ack = 0;
+    GS_outb_in = GS_outb_out = GS_outb;
+    set_io(&gs_xio);
+    GS_ev_mask = GS_MASK_INIT;
+    (void) signal(SIGPIPE, SIG_IGN);
+    
+    if (resource.gs_safer)
+	gs_send(strsafe, (sizeof strsafe) - 1);
+    gs_send(str1, (sizeof str1) - 1);
+    gs_send(psheader, psheaderlen);
+    gs_send(str2, (sizeof str2) - 1);
+    waitack();
+    GS_in_header = False;
+    GS_ev_mask = GS_MASK_NORMAL;
+
+    if (GS_pid == 0) {	/* if something happened */
+	destroy_gs();
+	return False;
+    }
+    if (resource.postscript == 0)
+	toggle_gs(0);	/* if we got a 'v' already */
+    else {
+	scanned_page = scanned_page_ps = scanned_page_reset;
+	globals.ev.flags |= EV_NEWPAGE;	/* ||| redraw the page */
+	longjmp(globals.ev.canit, 1);
+    }
+    return True;
+}
+
+static void
+toggle_gs(int flag)	/* this routine is callable from within read_events().  */
+{
+    if (globals.debug & DBG_PS)
+	fprintf(stdout, "Toggling GS to %d", flag);
+
+    switch (flag) {
+    case 0:
+	psp.drawbegin = drawbegin_none;
+	break;
+    case 1:
+	psp.drawbegin = drawbegin_gs;
+	break;
+    default:
+	psp.drawbegin = drawbegin_gs_box;
+	break;
+    }
+}
+
+void
+gs_resume_prescan()
+{
+    if (globals.debug & DBG_PS)
+	puts("Resuming prescan");
+    
+    gs_postpone_prescan = False;
+    if (!initGS())	/* this may not return */
+	psp = no_ps_procs;
+}
+
+static void
+gs_died(int status, struct xchild *child)
+{
+    UNUSED(status);
+    if (globals.debug & DBG_PS)
+	fprintf(stderr, "process %s died\n", child->name);
+    GS_pid = 0;
+    (child->io->read_proc)(child->io->fd);
+    if (linepos > line) {
+	*linepos = '\0';
+	printf("%s: %s\n", child->name, line);
+	linepos = line;
+    }
+    clear_io(child->io);
+    (void)close(child->io->fd);
+
+    scanned_page = scanned_page_ps = scanned_page_reset;
+    GS_active = GS_in_doc = False;
+    GS_pending = 0;
+    globals.ev.flags |= GS_die_ack;
+}
+
+static	void
+destroy_gs(void)
+{
+    if (globals.debug & DBG_PS)
+	puts("Destroying GS process");
+    if (GS_pid != 0) {
+	if (kill(GS_pid, SIGKILL) < 0 && errno != ESRCH)
+	    perror("xdvik: destroy_gs");
+	GS_pid = 0;
+	clear_chld(&gs_child);
+	read_from_gs(GS_fd);
+	if (linepos > line) {
+	    *linepos = '\0';
+	    printf("gs: %s\n", line);
+	    linepos = line;
+	}
+	clear_io(&gs_xio);
+	(void) close(GS_fd);
+
+	scanned_page = scanned_page_ps = scanned_page_reset;
+    }
+    GS_active = GS_in_doc = False;
+    GS_pending = 0;
+}
+
+static void
+deactivate(void)
+{
+    static const char str[] = " stop\n%%xdvimark\n";
+    int	saved_mask;
+
+    saved_mask = GS_ev_mask;
+    GS_ev_mask = 0;
+    gs_send(str, (sizeof str) - 1);
+    GS_ev_mask = saved_mask;
+
+    GS_active = False;
+}
+
+static void
+interrupt_gs(void)
+{
+    if (globals.debug & DBG_PS)
+	puts("Running interrupt_gs()");
+    /*
+      FIXME: added this special case, since otherwise EV_ACK might not get
+      reset at all, and hang xdvi forever when scrolling quickly through
+      a file that should be reloaded.
+    */
+    if (GS_pending == 0) {
+/*  	fprintf(stderr, "+++++++++ 1st case; waitack: %d\n", globals.ev.flags & EV_ACK); */
+	globals.ev.flags &= ~EV_ACK;
+	return;
+    }
+    else if (GS_pending < 0) {
+/*  	fprintf(stderr, "GS_pending: %d; waitack: %d\n", GS_pending, globals.ev.flags & EV_ACK); */
+	return;	/* nothing to do */
+    }
+
+    /*
+     * ||| what I'd really like to do here is cause gs to execute
+     * the interrupt routine in errordict.  But so far (gs 2.6.1)
+     * that has not been implemented in ghostscript.
+     */
+
+    if (GS_active)
+	deactivate();
+    waitack();
+}
+
+static void
+endpage_gs(void)
+{
+    if (globals.debug & DBG_PS)
+	puts("Running endpage_gs()");
+    if (GS_active) {
+	deactivate();
+	waitack();
+    }
+}
+
+/*
+ *	Checks that the GS interpreter is running correctly.
+ */
+
+static void
+checkgs(Boolean in_header)
+{
+    char buf[150];
+
+    /* For gs 2, we pretty much have to start over to enlarge the window. */
+    if ((GS_old && (globals.page.w > GS_page_w || globals.page.h > GS_page_h))
+	|| GS_alpha != resource.gs_alpha)
+	destroy_gs();
+
+    if (GS_pid == 0)
+	(void)initGS();
+
+    if (!GS_active) {
+	/* check whether page_w or page_h have increased */
+	if (globals.page.w > GS_page_w || globals.page.h > GS_page_h) {
+	    if (globals.ev.flags & GS_ev_mask)
+		longjmp(globals.ev.canit, 1);
+	    ++GS_pending;
+	    sprintf(buf,
+		    "H mark /HWSize [%d %d] /ImagingBBox [0 0 %d %d] "
+		    "currentdevice putdeviceprops pop\n"
+		    "initgraphics [0 1 1 0 0 0] concat stop\n"
+		    "%%%%xdvimark\n",
+		    GS_page_w = globals.page.w,
+		    GS_page_h = globals.page.h,
+		    globals.page.h,
+		    globals.page.w);
+	    gs_send(buf, strlen(buf));
+	    if (!in_header) {
+		globals.ev.flags |= EV_NEWPAGE;	/* ||| redraw the page */
+		longjmp(globals.ev.canit, 1);
+	    }
+	}
+
+	if (magnification != GS_mag) {
+	    if (globals.ev.flags & GS_ev_mask)
+		longjmp(globals.ev.canit, 1);
+	    ++GS_pending;
+	    sprintf(buf,
+		    "H TeXDict begin /DVImag %ld 1000 div def end stop\n"
+		    "%%%%xdvimark\n",
+		    GS_mag = magnification);
+	    gs_send(buf, strlen(buf));
+	}
+
+	if (mane.shrinkfactor != GS_shrink) {
+	    if (globals.ev.flags & GS_ev_mask)
+		longjmp(globals.ev.canit, 1);
+	    ++GS_pending;
+	    sprintf(buf,
+		    "H TeXDict begin %d %d div dup /Resolution X /VResolution X end stop\n"
+		    "%%%%xdvimark\n",
+		    resource.pixels_per_inch,
+		    GS_shrink = mane.shrinkfactor);
+	    gs_send(buf, strlen(buf));
+	}
+    }
+}
+
+static void
+drawbegin_gs(int xul, int yul, const char *cp)
+{
+    char buf[32];
+    static const char str[] = " TeXDict begin\n";
+    
+    checkgs(False);
+
+    if (!GS_active) {
+	if (globals.ev.flags & GS_ev_mask)
+	    longjmp(globals.ev.canit, 1);
+	++GS_pending;
+	gs_send(str, (sizeof str) - 1);
+	GS_active = True;
+    }
+
+    /* This allows the X side to clear the page */
+    XSync(DISP, False);
+
+    sprintf(buf, "%d %d moveto\n", xul, yul);
+    gs_send(buf, strlen(buf));
+/*     gs_send(clear_bg, strlen(clear_bg)); */
+    if (globals.debug & DBG_PS)
+	printf("drawbegin at %d,%d:  sending `%s'\n", xul, yul, cp);
+
+    /*
+     * added SU 2000/12/18:
+     * Try to detect some simple PS rotating commands, and warn about them.
+     * There are surely more than that ...
+     */
+    if (strstr(cp, "rotate") != NULL	/* used by graphics.sty */
+	|| strstr(cp, "RotBegin") != NULL	/* used by pstricks */
+	) {
+	statusline_print(STATUS_SHORT,
+			 "Warning: PS code on page %d may contain rotation, "
+			 "which is not supported by xdvi", current_page + 1);
+    }
+
+    gs_send(cp, strlen(cp));
+}
+
+static void
+drawbegin_gs_box(int xul, int yul, const char *cp)
+{
+    drawbegin_gs(xul, yul, cp);
+}
+
+
+void
+drawraw_gs(const char *cp)
+{
+    if (!GS_active)
+	return;
+    if (globals.debug & DBG_PS)
+	printf("raw ps sent to context: %s\n", cp);
+    gs_send(cp, strlen(cp));
+    gs_send("\n", 1);
+}
+
+static void
+drawfile_gs(const char *cp, FILE *f)
+{
+    char canonical_path[MAXPATHLEN + 1];
+    char *ret;
+
+    fclose(f);	/* don't need it */
+
+    if (!GS_active)
+	return;
+
+    if (globals.debug & DBG_PS)
+	printf("original path: |%s|\n", cp);
+/*     drawraw_gs("newpath 0 0 moveto 0 1000 rlineto 1000 0 rlineto 0 -1000 rlineto closepath 1 setgray fill"); */
+#if 0
+    /* if expand_symlinks or remove_dots from kpathsea were public,
+       we could use the following: */
+    ret = remove_dots(expand_symlinks(cp));
+#endif
+
+    ret = REALPATH(cp, canonical_path);
+    if (ret == NULL)
+	XDVI_WARNING((stderr, "Couldn't canonicalize path \"%s\": %s. Sending to gs unchanged.",
+		      cp, strerror(errno)));
+    else
+	cp = canonical_path;
+
+    if (globals.debug & DBG_PS)
+	printf("expanded path: |%s|\n", cp);
+
+    gs_send("(", 1);
+    gs_send(cp, strlen(cp));
+    gs_send(")run\n", 5);
+/*     { */
+/* 	char *clear_bg = "newpath 0 0 moveto 0 1000 rlineto 1000 0 rlineto 0 -1000 rlineto closepath .4 setgray fill\n"; */
+/* 	gs_send(clear_bg, strlen(clear_bg)); */
+/*     } */
+}
+
+static void
+drawend_gs(const char *cp)
+{
+    if (!GS_active)
+	return;
+    if (globals.debug & DBG_PS)
+	printf("end ps: %s\n", cp);
+    gs_send(cp, strlen(cp));
+    gs_send("\n", 1);
+    save_bbox();
+}
+
+static void
+beginheader_gs(void)
+{
+    static const char str[] = "Hsave /xdvi$doc exch def\n";
+
+    if (globals.debug & DBG_PS)
+	puts("Running beginheader_gs()");
+
+    checkgs(True);
+
+    if (GS_active) {
+	if (!GS_in_header)
+	    XDVI_FATAL((stderr, "Internal error in beginheader_gs()."));
+	return;
+    }
+
+    if (globals.ev.flags & GS_ev_mask) {
+/* 	fprintf(stderr, "longjmp!"); */
+	longjmp(globals.ev.canit, 1);
+    }
+
+    GS_in_header = True;
+    GS_ev_mask = GS_MASK_HEADER;
+    ++GS_pending;
+    if (GS_in_doc)
+	gs_send("H", 1);
+    else {
+	gs_send(str, (sizeof str) - 1);
+	GS_in_doc = True;
+    }
+    GS_active = True;
+}
+
+static void
+endheader_gs(void)
+{
+    if (globals.debug & DBG_PS)
+	puts("Running endheader_gs()");
+
+    if (GS_active) {
+	deactivate();
+	waitack();
+	GS_in_header = False;
+	GS_ev_mask = GS_MASK_NORMAL;
+    }
+}
+
+static void
+newdoc_gs(void)
+{
+    static const char str[] = "Hxdvi$doc restore stop\n%%xdvimark\n";
+
+    if (globals.debug & DBG_PS)
+	puts("Running newdoc_gs()");
+
+    if (GS_in_doc) {
+	++GS_pending;
+	gs_send(str, (sizeof str) - 1);
+	GS_mag = GS_shrink = -1;
+	GS_in_doc = False;
+
+	if (!GS_old) GS_page_w = GS_page_h = 0;
+    }
+}
+
+void erasepage_gs(void)
+{
+    /* In buffered mode, gs has no way of knowing that the screen has been 
+       erased. Clear the gs window buffer with an erasepage command. */ 
+    
+    if (resource.gs_alpha && GS_pid > 0 && !GS_active) {
+	if (globals.debug & DBG_PS)
+	    puts("erasing page!");
+	beginheader_gs();
+	drawraw_gs("erasepage");
+	endheader_gs();
+    }
+}
+
+#else
+/* silence `empty compilation unit' warnings */
+static void bar(void); static void foo() { bar(); } static void bar(void) { foo(); }
+#endif /* PS_GS */