diff options
author | Taco Hoekwater <taco@elvenkind.com> | 2010-04-04 13:55:46 +0000 |
---|---|---|
committer | Taco Hoekwater <taco@elvenkind.com> | 2010-04-04 13:55:46 +0000 |
commit | f372862c42d234710b6057449b46818e63181c90 (patch) | |
tree | a9ebec66dd31ac37aed442502ebd1b9fe76245ec /Build/source/texk/web2c/luatexdir/dvi | |
parent | 2dad291ab056f30816e0aea61970f38033c2f6a5 (diff) |
import luatex 0.60.0 (with small local changes, see luatexdir/ChangeLog)
and do an autoreconf
git-svn-id: svn://tug.org/texlive/trunk@17680 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Build/source/texk/web2c/luatexdir/dvi')
-rw-r--r-- | Build/source/texk/web2c/luatexdir/dvi/dvigen.h | 193 | ||||
-rw-r--r-- | Build/source/texk/web2c/luatexdir/dvi/dvigen.w | 1420 |
2 files changed, 1613 insertions, 0 deletions
diff --git a/Build/source/texk/web2c/luatexdir/dvi/dvigen.h b/Build/source/texk/web2c/luatexdir/dvi/dvigen.h new file mode 100644 index 00000000000..29989a3e10c --- /dev/null +++ b/Build/source/texk/web2c/luatexdir/dvi/dvigen.h @@ -0,0 +1,193 @@ +/* dvigen.h + + Copyright 2009 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 General Public License as published by the Free + Software Foundation; either version 2 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 General Public License along + with LuaTeX; if not, see <http://www.gnu.org/licenses/>. */ + +/* $Id: dvigen.h 3404 2010-01-28 11:17:10Z taco $ */ + +#ifndef DVIGEN_H +# define DVIGEN_H + +extern int total_pages; +extern scaled max_v; +extern scaled max_h; +extern int max_push; +extern int last_bop; +extern int dead_cycles; +extern boolean doing_leaders; +extern int c, f; +extern int oval, ocmd; +extern halfword g; +extern int lq, lr; +extern int cur_s; + +typedef int dvi_index; /* an index into the output buffer */ + +extern int dvi_buf_size; +extern eight_bits *dvi_buf; /* 0 is unused */ +extern dvi_index half_buf; +extern dvi_index dvi_limit; +extern dvi_index dvi_ptr; +extern int dvi_offset; +extern int dvi_gone; + +/* +To put a byte in the buffer without paying the cost of invoking a procedure +each time, we use the macro |dvi_out|. +*/ + +# define dvi_out(A) do { \ + dvi_buf[dvi_ptr++]=(eight_bits)(A); \ + if (dvi_ptr==dvi_limit) dvi_swap(); \ + } while (0) + +extern void dvi_swap(void); +extern void dvi_four(int x); +extern void dvi_push(void); +extern void dvi_pop(int l); +extern void out_cmd(void); +extern void dvi_font_def(internal_font_number f); + +# define dvi_set(A,B) do { \ + oval=A; ocmd=set1; out_cmd(); dvi.h += (B); \ + } while (0) + +# define dvi_put(A) do { \ + oval=A; ocmd=put1; out_cmd(); \ + } while (0) + +# define location(A) varmem[(A)+1].cint + +extern halfword down_ptr, right_ptr; /* heads of the down and right stacks */ + +/* +The |vinfo| fields in the entries of the down stack or the right stack +have six possible settings: |y_here| or |z_here| mean that the \.{DVI} +command refers to |y| or |z|, respectively (or to |w| or |x|, in the +case of horizontal motion); |yz_OK| means that the \.{DVI} command is +\\{down} (or \\{right}) but can be changed to either |y| or |z| (or +to either |w| or |x|); |y_OK| means that it is \\{down} and can be changed +to |y| but not |z|; |z_OK| is similar; and |d_fixed| means it must stay +\\{down}. + +The four settings |yz_OK|, |y_OK|, |z_OK|, |d_fixed| would not need to +be distinguished from each other if we were simply solving the +digit-subscripting problem mentioned above. But in \TeX's case there is +a complication because of the nested structure of |push| and |pop| +commands. Suppose we add parentheses to the digit-subscripting problem, +redefining hits so that $\delta_y\ldots \delta_y$ is a hit if all $y$'s between +the $\delta$'s are enclosed in properly nested parentheses, and if the +parenthesis level of the right-hand $\delta_y$ is deeper than or equal to +that of the left-hand one. Thus, `(' and `)' correspond to `|push|' +and `|pop|'. Now if we want to assign a subscript to the final 1 in the +sequence +$$2_y\,7_d\,1_d\,(\,8_z\,2_y\,8_z\,)\,1$$ +we cannot change the previous $1_d$ to $1_y$, since that would invalidate +the $2_y\ldots2_y$ hit. But we can change it to $1_z$, scoring a hit +since the intervening $8_z$'s are enclosed in parentheses. +*/ + +typedef enum { + y_here = 1, /* |vinfo| when the movement entry points to a |y| command */ + z_here = 2, /* |vinfo| when the movement entry points to a |z| command */ + yz_OK = 3, /* |vinfo| corresponding to an unconstrained \\{down} command */ + y_OK = 4, /* |vinfo| corresponding to a \\{down} that can't become a |z| */ + z_OK = 5, /* |vinfo| corresponding to a \\{down} that can't become a |y| */ + d_fixed = 6, /* |vinfo| corresponding to a \\{down} that can't change */ +} movement_codes; + +/* As we search through the stack, we are in one of three states, + |y_seen|, |z_seen|, or |none_seen|, depending on whether we have + encountered |y_here| or |z_here| nodes. These states are encoded as + multiples of 6, so that they can be added to the |info| fields for quick + decision-making. */ + +# define none_seen 0 /* no |y_here| or |z_here| nodes have been encountered yet */ +# define y_seen 6 /* we have seen |y_here| but not |z_here| */ +# define z_seen 12 /* we have seen |z_here| but not |y_here| */ + +extern void movement(scaled w, eight_bits o); +extern void prune_movements(int l); + +/* +The actual distances by which we want to move might be computed as the +sum of several separate movements. For example, there might be several +glue nodes in succession, or we might want to move right by the width of +some box plus some amount of glue. More importantly, the baselineskip +distances are computed in terms of glue together with the depth and +height of adjacent boxes, and we want the \.{DVI} file to lump these +three quantities together into a single motion. + +Therefore, \TeX\ maintains two pairs of global variables: |dvi.h| and |dvi.v| +are the |h| and |v| coordinates corresponding to the commands actually +output to the \.{DVI} file, while |cur.h| and |cur.v| are the coordinates +corresponding to the current state of the output routines. Coordinate +changes will accumulate in |cur.h| and |cur.v| without being reflected +in the output, until such a change becomes necessary or desirable; we +can call the |movement| procedure whenever we want to make |dvi.h=pos.h| +or |dvi.v=pos.v|. + +The current font reflected in the \.{DVI} output is called |dvi_f|; +there is no need for a `\\{cur\_f}' variable. + +The depth of nesting of |hlist_out| and |vlist_out| is called |cur_s|; +this is essentially the depth of |push| commands in the \.{DVI} output. +*/ + +# define synch_h(p) do { \ + if (p.h != dvi.h) { \ + movement(p.h - dvi.h, right1); \ + dvi.h = p.h; \ + } \ + } while (0) + +# define synch_v(p) do { \ + if (p.v != dvi.v) { \ + movement(dvi.v - p.v, down1); \ + dvi.v = p.v; \ + } \ + } while (0) + +# define synch_dvi_with_pos(p) do {synch_h(p); synch_v(p); } while (0) + +# define billion 1000000000.0 + +# define vet_glue(A) do { glue_temp=A; \ + if (glue_temp>billion) \ + glue_temp=billion; \ + else if (glue_temp<-billion) \ + glue_temp=-billion; \ + } while (0) + +extern scaled_whd rule; +extern scaledpos dvi; +extern scaledpos cur_page_size; /* width and height of page being shipped */ + +extern void expand_macros_in_tokenlist(halfword p); +extern void write_out(halfword p); +extern void dvi_special(PDF pdf, halfword p); + +extern void ensure_dvi_header_written(PDF pdf); +extern void finish_dvi_file(PDF pdf, int version, int revision); + +extern void dvi_place_glyph(PDF pdf, internal_font_number f, int c); +extern void dvi_place_rule(PDF pdf, halfword q, scaledpos size); + +extern void dvi_begin_page(PDF pdf); +extern void dvi_end_page(PDF pdf); + +#endif diff --git a/Build/source/texk/web2c/luatexdir/dvi/dvigen.w b/Build/source/texk/web2c/luatexdir/dvi/dvigen.w new file mode 100644 index 00000000000..240d589fee1 --- /dev/null +++ b/Build/source/texk/web2c/luatexdir/dvi/dvigen.w @@ -0,0 +1,1420 @@ +%dvigen.w + +%Copyright 2009-2010 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 General Public License as published by the Free +%Software Foundation; either version 2 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 General Public License along +%with LuaTeX; if not, see <http://www.gnu.org/licenses/>. + +\def\MF{MetaFont} +\def\MP{MetaPost} +\def\PASCAL{Pascal} +\def\[#1]{#1} +\pdfoutput=1 +\pdfmapline{cmtex10 < cmtex10.pfb} +\pdfmapfile{pdftex.map} + +\title{: generation of DVI output} + +@ Initial identification of this file, and the needed headers. +@c +static const char _svn_version[] = + "$Id: dvigen.w 3535 2010-03-21 17:02:05Z oneiros $" + "$URL: http://foundry.supelec.fr/svn/luatex/tags/beta-0.60.0/source/texk/web2c/luatexdir/dvi/dvigen.w $"; + +#include "ptexlib.h" + +@ Here is the start of the actual C file. +@c +#undef write_dvi + +#define mode cur_list.mode_field /* current mode */ + +#define pdf_output int_par(pdf_output_code) +#define mag int_par(mag_code) +#define tracing_output int_par(tracing_output_code) +#define tracing_stats int_par(tracing_stats_code) +#define tracing_online int_par(tracing_online_code) +#define page_direction int_par(page_direction_code) +#define page_width dimen_par(page_width_code) +#define page_height dimen_par(page_height_code) +#define page_left_offset dimen_par(page_left_offset_code) +#define page_right_offset dimen_par(page_right_offset_code) +#define page_top_offset dimen_par(page_top_offset_code) +#define page_bottom_offset dimen_par(page_bottom_offset_code) +#define h_offset dimen_par(h_offset_code) +#define v_offset dimen_par(v_offset_code) + +#define count(A) eqtb[count_base+(A)].cint + +@ The most important output produced by a run of \TeX\ is the ``device +independent'' (\.{DVI}) file that specifies where characters and rules +are to appear on printed pages. The form of these files was designed by +David R. Fuchs in 1979. Almost any reasonable typesetting device can be +@^Fuchs, David Raymond@> +@:DVI_files}{\.{DVI} files@> +driven by a program that takes \.{DVI} files as input, and dozens of such +\.{DVI}-to-whatever programs have been written. Thus, it is possible to +print the output of \TeX\ on many different kinds of equipment, using \TeX\ +as a device-independent ``front end.'' + +A \.{DVI} file is a stream of 8-bit bytes, which may be regarded as a +series of commands in a machine-like language. The first byte of each command +is the operation code, and this code is followed by zero or more bytes +that provide parameters to the command. The parameters themselves may consist +of several consecutive bytes; for example, the `|set_rule|' command has two +parameters, each of which is four bytes long. Parameters are usually +regarded as nonnegative integers; but four-byte-long parameters, +and shorter parameters that denote distances, can be +either positive or negative. Such parameters are given in two's complement +notation. For example, a two-byte-long distance parameter has a value between +$-2^{15}$ and $2^{15}-1$. As in \.{TFM} files, numbers that occupy +more than one byte position appear in BigEndian order. + +A \.{DVI} file consists of a ``preamble,'' followed by a sequence of one +or more ``pages,'' followed by a ``postamble.'' The preamble is simply a +|pre| command, with its parameters that define the dimensions used in the +file; this must come first. Each ``page'' consists of a |bop| command, +followed by any number of other commands that tell where characters are to +be placed on a physical page, followed by an |eop| command. The pages +appear in the order that \TeX\ generated them. If we ignore |nop| commands +and \\{fnt\_def} commands (which are allowed between any two commands in +the file), each |eop| command is immediately followed by a |bop| command, +or by a |post| command; in the latter case, there are no more pages in the +file, and the remaining bytes form the postamble. Further details about +the postamble will be explained later. + +Some parameters in \.{DVI} commands are ``pointers.'' These are four-byte +quantities that give the location number of some other byte in the file; +the first byte is number~0, then comes number~1, and so on. For example, +one of the parameters of a |bop| command points to the previous |bop|; +this makes it feasible to read the pages in backwards order, in case the +results are being directed to a device that stacks its output face up. +Suppose the preamble of a \.{DVI} file occupies bytes 0 to 99. Now if the +first page occupies bytes 100 to 999, say, and if the second +page occupies bytes 1000 to 1999, then the |bop| that starts in byte 1000 +points to 100 and the |bop| that starts in byte 2000 points to 1000. (The +very first |bop|, i.e., the one starting in byte 100, has a pointer of~$-1$.) + +@ The \.{DVI} format is intended to be both compact and easily interpreted +by a machine. Compactness is achieved by making most of the information +implicit instead of explicit. When a \.{DVI}-reading program reads the +commands for a page, it keeps track of several quantities: (a)~The current +font |f| is an integer; this value is changed only +by \\{fnt} and \\{fnt\_num} commands. (b)~The current position on the page +is given by two numbers called the horizontal and vertical coordinates, +|h| and |v|. Both coordinates are zero at the upper left corner of the page; +moving to the right corresponds to increasing the horizontal coordinate, and +moving down corresponds to increasing the vertical coordinate. Thus, the +coordinates are essentially Cartesian, except that vertical directions are +flipped; the Cartesian version of |(h,v)| would be |(h,-v)|. (c)~The +current spacing amounts are given by four numbers |w|, |x|, |y|, and |z|, +where |w| and~|x| are used for horizontal spacing and where |y| and~|z| +are used for vertical spacing. (d)~There is a stack containing +|(h,v,w,x,y,z)| values; the \.{DVI} commands |push| and |pop| are used to +change the current level of operation. Note that the current font~|f| is +not pushed and popped; the stack contains only information about +positioning. + +The values of |h|, |v|, |w|, |x|, |y|, and |z| are signed integers having up +to 32 bits, including the sign. Since they represent physical distances, +there is a small unit of measurement such that increasing |h| by~1 means +moving a certain tiny distance to the right. The actual unit of +measurement is variable, as explained below; \TeX\ sets things up so that +its \.{DVI} output is in sp units, i.e., scaled points, in agreement with +all the |scaled| dimensions in \TeX's data structures. + +@ Here is a list of all the commands that may appear in a \.{DVI} file. Each +command is specified by its symbolic name (e.g., |bop|), its opcode byte +(e.g., 139), and its parameters (if any). The parameters are followed +by a bracketed number telling how many bytes they occupy; for example, +`|p[4]|' means that parameter |p| is four bytes long. + +\yskip\hang|set_char_0| 0. Typeset character number~0 from font~|f| +such that the reference point of the character is at |(h,v)|. Then +increase |h| by the width of that character. Note that a character may +have zero or negative width, so one cannot be sure that |h| will advance +after this command; but |h| usually does increase. + +\yskip\hang\\{set\_char\_1} through \\{set\_char\_127} (opcodes 1 to 127). +Do the operations of |set_char_0|; but use the character whose number +matches the opcode, instead of character~0. + +\yskip\hang|set1| 128 |c[1]|. Same as |set_char_0|, except that character +number~|c| is typeset. \TeX82 uses this command for characters in the +range |128<=c<256|. + +\yskip\hang|@!set2| 129 |c[2]|. Same as |set1|, except that |c|~is two +bytes long, so it is in the range |0<=c<65536|. \TeX82 never uses this +command, but it should come in handy for extensions of \TeX\ that deal +with oriental languages. +@^oriental characters@>@^Chinese characters@>@^Japanese characters@> + +\yskip\hang|@!set3| 130 |c[3]|. Same as |set1|, except that |c|~is three +bytes long, so it can be as large as $2^{24}-1$. Not even the Chinese +language has this many characters, but this command might prove useful +in some yet unforeseen extension. + +\yskip\hang|@!set4| 131 |c[4]|. Same as |set1|, except that |c|~is four +bytes long. Imagine that. + +\yskip\hang|set_rule| 132 |a[4]| |b[4]|. Typeset a solid black rectangle +of height~|a| and width~|b|, with its bottom left corner at |(h,v)|. Then +set |h:=h+b|. If either |a<=0| or |b<=0|, nothing should be typeset. Note +that if |b<0|, the value of |h| will decrease even though nothing else happens. +See below for details about how to typeset rules so that consistency with +\MF\ is guaranteed. + +\yskip\hang|@!put1| 133 |c[1]|. Typeset character number~|c| from font~|f| +such that the reference point of the character is at |(h,v)|. (The `put' +commands are exactly like the `set' commands, except that they simply put out a +character or a rule without moving the reference point afterwards.) + +\yskip\hang|@!put2| 134 |c[2]|. Same as |set2|, except that |h| is not changed. + +\yskip\hang|@!put3| 135 |c[3]|. Same as |set3|, except that |h| is not changed. + +\yskip\hang|@!put4| 136 |c[4]|. Same as |set4|, except that |h| is not changed. + +\yskip\hang|put_rule| 137 |a[4]| |b[4]|. Same as |set_rule|, except that +|h| is not changed. + +\yskip\hang|nop| 138. No operation, do nothing. Any number of |nop|'s +may occur between \.{DVI} commands, but a |nop| cannot be inserted between +a command and its parameters or between two parameters. + +\yskip\hang|bop| 139 $c_0[4]$ $c_1[4]$ $\ldots$ $c_9[4]$ $p[4]$. Beginning +of a page: Set |(h,v,w,x,y,z):=(0,0,0,0,0,0)| and set the stack empty. Set +the current font |f| to an undefined value. The ten $c_i$ parameters hold +the values of \.{\\count0} $\ldots$ \.{\\count9} in \TeX\ at the time +\.{\\shipout} was invoked for this page; they can be used to identify +pages, if a user wants to print only part of a \.{DVI} file. The parameter +|p| points to the previous |bop| in the file; the first +|bop| has $p=-1$. + +\yskip\hang|eop| 140. End of page: Print what you have read since the +previous |bop|. At this point the stack should be empty. (The \.{DVI}-reading +programs that drive most output devices will have kept a buffer of the +material that appears on the page that has just ended. This material is +largely, but not entirely, in order by |v| coordinate and (for fixed |v|) by +|h|~coordinate; so it usually needs to be sorted into some order that is +appropriate for the device in question.) + +\yskip\hang|push| 141. Push the current values of |(h,v,w,x,y,z)| onto the +top of the stack; do not change any of these values. Note that |f| is +not pushed. + +\yskip\hang|pop| 142. Pop the top six values off of the stack and assign +them respectively to |(h,v,w,x,y,z)|. The number of pops should never +exceed the number of pushes, since it would be highly embarrassing if the +stack were empty at the time of a |pop| command. + +\yskip\hang|right1| 143 |b[1]|. Set |h:=h+b|, i.e., move right |b| units. +The parameter is a signed number in two's complement notation, |-128<=b<128|; +if |b<0|, the reference point moves left. + +\yskip\hang|right2| 144 |b[2]|. Same as |right1|, except that |b| is a +two-byte quantity in the range |-32768<=b<32768|. + +\yskip\hang|right3| 145 |b[3]|. Same as |right1|, except that |b| is a +three-byte quantity in the range |@t$-2^{23}$@><=b<@t$2^{23}$@>|. + +\yskip\hang|right4| 146 |b[4]|. Same as |right1|, except that |b| is a +four-byte quantity in the range |@t$-2^{31}$@><=b<@t$2^{31}$@>|. + +\yskip\hang|w0| 147. Set |h:=h+w|; i.e., move right |w| units. With luck, +this parameterless command will usually suffice, because the same kind of motion +will occur several times in succession; the following commands explain how +|w| gets particular values. + +\yskip\hang|w1| 148 |b[1]|. Set |w:=b| and |h:=h+b|. The value of |b| is a +signed quantity in two's complement notation, |-128<=b<128|. This command +changes the current |w|~spacing and moves right by |b|. + +\yskip\hang|@!w2| 149 |b[2]|. Same as |w1|, but |b| is two bytes long, +|-32768<=b<32768|. + +\yskip\hang|@!w3| 150 |b[3]|. Same as |w1|, but |b| is three bytes long, +|@t$-2^{23}$@><=b<@t$2^{23}$@>|. + +\yskip\hang|@!w4| 151 |b[4]|. Same as |w1|, but |b| is four bytes long, +|@t$-2^{31}$@><=b<@t$2^{31}$@>|. + +\yskip\hang|x0| 152. Set |h:=h+x|; i.e., move right |x| units. The `|x|' +commands are like the `|w|' commands except that they involve |x| instead +of |w|. + +\yskip\hang|x1| 153 |b[1]|. Set |x:=b| and |h:=h+b|. The value of |b| is a +signed quantity in two's complement notation, |-128<=b<128|. This command +changes the current |x|~spacing and moves right by |b|. + +\yskip\hang|@!x2| 154 |b[2]|. Same as |x1|, but |b| is two bytes long, +|-32768<=b<32768|. + +\yskip\hang|@!x3| 155 |b[3]|. Same as |x1|, but |b| is three bytes long, +|@t$-2^{23}$@><=b<@t$2^{23}$@>|. + +\yskip\hang|@!x4| 156 |b[4]|. Same as |x1|, but |b| is four bytes long, +|@t$-2^{31}$@><=b<@t$2^{31}$@>|. + +\yskip\hang|down1| 157 |a[1]|. Set |v:=v+a|, i.e., move down |a| units. +The parameter is a signed number in two's complement notation, |-128<=a<128|; +if |a<0|, the reference point moves up. + +\yskip\hang|@!down2| 158 |a[2]|. Same as |down1|, except that |a| is a +two-byte quantity in the range |-32768<=a<32768|. + +\yskip\hang|@!down3| 159 |a[3]|. Same as |down1|, except that |a| is a +three-byte quantity in the range |@t$-2^{23}$@><=a<@t$2^{23}$@>|. + +\yskip\hang|@!down4| 160 |a[4]|. Same as |down1|, except that |a| is a +four-byte quantity in the range |@t$-2^{31}$@><=a<@t$2^{31}$@>|. + +\yskip\hang|y0| 161. Set |v:=v+y|; i.e., move down |y| units. With luck, +this parameterless command will usually suffice, because the same kind of motion +will occur several times in succession; the following commands explain how +|y| gets particular values. + +\yskip\hang|y1| 162 |a[1]|. Set |y:=a| and |v:=v+a|. The value of |a| is a +signed quantity in two's complement notation, |-128<=a<128|. This command +changes the current |y|~spacing and moves down by |a|. + +\yskip\hang|@!y2| 163 |a[2]|. Same as |y1|, but |a| is two bytes long, +|-32768<=a<32768|. + +\yskip\hang|@!y3| 164 |a[3]|. Same as |y1|, but |a| is three bytes long, +|@t$-2^{23}$@><=a<@t$2^{23}$@>|. + +\yskip\hang|@!y4| 165 |a[4]|. Same as |y1|, but |a| is four bytes long, +|@t$-2^{31}$@><=a<@t$2^{31}$@>|. + +\yskip\hang|z0| 166. Set |v:=v+z|; i.e., move down |z| units. The `|z|' commands +are like the `|y|' commands except that they involve |z| instead of |y|. + +\yskip\hang|z1| 167 |a[1]|. Set |z:=a| and |v:=v+a|. The value of |a| is a +signed quantity in two's complement notation, |-128<=a<128|. This command +changes the current |z|~spacing and moves down by |a|. + +\yskip\hang|@!z2| 168 |a[2]|. Same as |z1|, but |a| is two bytes long, +|-32768<=a<32768|. + +\yskip\hang|@!z3| 169 |a[3]|. Same as |z1|, but |a| is three bytes long, +|@t$-2^{23}$@><=a<@t$2^{23}$@>|. + +\yskip\hang|@!z4| 170 |a[4]|. Same as |z1|, but |a| is four bytes long, +|@t$-2^{31}$@><=a<@t$2^{31}$@>|. + +\yskip\hang|fnt_num_0| 171. Set |f:=0|. Font 0 must previously have been +defined by a \\{fnt\_def} instruction, as explained below. + +\yskip\hang\\{fnt\_num\_1} through \\{fnt\_num\_63} (opcodes 172 to 234). Set +|f:=1|, \dots, \hbox{|f:=63|}, respectively. + +\yskip\hang|fnt1| 235 |k[1]|. Set |f:=k|. \TeX82 uses this command for font +numbers in the range |64<=k<256|. + +\yskip\hang|@!fnt2| 236 |k[2]|. Same as |fnt1|, except that |k|~is two +bytes long, so it is in the range |0<=k<65536|. \TeX82 never generates this +command, but large font numbers may prove useful for specifications of +color or texture, or they may be used for special fonts that have fixed +numbers in some external coding scheme. + +\yskip\hang|@!fnt3| 237 |k[3]|. Same as |fnt1|, except that |k|~is three +bytes long, so it can be as large as $2^{24}-1$. + +\yskip\hang|@!fnt4| 238 |k[4]|. Same as |fnt1|, except that |k|~is four +bytes long; this is for the really big font numbers (and for the negative ones). + +\yskip\hang|xxx1| 239 |k[1]| |x[k]|. This command is undefined in +general; it functions as a $(k+2)$-byte |nop| unless special \.{DVI}-reading +programs are being used. \TeX82 generates |xxx1| when a short enough +\.{\\special} appears, setting |k| to the number of bytes being sent. It +is recommended that |x| be a string having the form of a keyword followed +by possible parameters relevant to that keyword. + +\yskip\hang|@!xxx2| 240 |k[2]| |x[k]|. Like |xxx1|, but |0<=k<65536|. + +\yskip\hang|@!xxx3| 241 |k[3]| |x[k]|. Like |xxx1|, but |0<=k<@t$2^{24}$@>|. + +\yskip\hang|xxx4| 242 |k[4]| |x[k]|. Like |xxx1|, but |k| can be ridiculously +large. \TeX82 uses |xxx4| when sending a string of length 256 or more. + +\yskip\hang|fnt_def1| 243 |k[1]| |c[4]| |s[4]| |d[4]| |a[1]| |l[1]| |n[a+l]|. +Define font |k|, where |0<=k<256|; font definitions will be explained shortly. + +\yskip\hang|@!fnt_def2| 244 |k[2]| |c[4]| |s[4]| |d[4]| |a[1]| |l[1]| |n[a+l]|. +Define font |k|, where |0<=k<65536|. + +\yskip\hang|@!fnt_def3| 245 |k[3]| |c[4]| |s[4]| |d[4]| |a[1]| |l[1]| |n[a+l]|. +Define font |k|, where |0<=k<@t$2^{24}$@>|. + +\yskip\hang|@!fnt_def4| 246 |k[4]| |c[4]| |s[4]| |d[4]| |a[1]| |l[1]| |n[a+l]|. +Define font |k|, where |@t$-2^{31}$@><=k<@t$2^{31}$@>|. + +\yskip\hang|pre| 247 |i[1]| |num[4]| |den[4]| |mag[4]| |k[1]| |x[k]|. +Beginning of the preamble; this must come at the very beginning of the +file. Parameters |i|, |num|, |den|, |mag|, |k|, and |x| are explained below. + +\yskip\hang|post| 248. Beginning of the postamble, see below. + +\yskip\hang|post_post| 249. Ending of the postamble, see below. + +\yskip\noindent Commands 250--255 are undefined at the present time. + +@c +#define set_char_0 0 /* typeset character 0 and move right */ +#define set1 128 /* typeset a character and move right */ +#define set_rule 132 /* typeset a rule and move right */ +#define put1 133 /* typeset a character without moving */ +#define put_rule 137 /* typeset a rule */ +#define nop 138 /* no operation */ +#define bop 139 /* beginning of page */ +#define eop 140 /* ending of page */ +#define push 141 /* save the current positions */ +#define pop 142 /* restore previous positions */ +#define right1 143 /* move right */ +#define right4 146 /* move right, 4 bytes */ +#define w0 147 /* move right by |w| */ +#define w1 148 /* move right and set |w| */ +#define x0 152 /* move right by |x| */ +#define x1 153 /* move right and set |x| */ +#define down1 157 /* move down */ +#define down4 160 /* move down, 4 bytes */ +#define y0 161 /* move down by |y| */ +#define y1 162 /* move down and set |y| */ +#define z0 166 /* move down by |z| */ +#define z1 167 /* move down and set |z| */ +#define fnt_num_0 171 /* set current font to 0 */ +#define fnt1 235 /* set current font */ +#define xxx1 239 /* extension to \.{DVI} primitives */ +#define xxx4 242 /* potentially long extension to \.{DVI} primitives */ +#define fnt_def1 243 /* define the meaning of a font number */ +#define pre 247 /* preamble */ +#define post 248 /* postamble beginning */ +#define post_post 249 /* postamble ending */ + +@ The preamble contains basic information about the file as a whole. As +stated above, there are six parameters: +$$\hbox{|@!i[1]| |@!num[4]| |@!den[4]| |@!mag[4]| |@!k[1]| |@!x[k]|.}$$ +The |i| byte identifies \.{DVI} format; currently this byte is always set +to~2. (The value |i=3| is currently used for an extended format that +allows a mixture of right-to-left and left-to-right typesetting. +Some day we will set |i=4|, when \.{DVI} format makes another +incompatible change---perhaps in the year 2048.) + +The next two parameters, |num| and |den|, are positive integers that define +the units of measurement; they are the numerator and denominator of a +fraction by which all dimensions in the \.{DVI} file could be multiplied +in order to get lengths in units of $10^{-7}$ meters. Since $\rm 7227{pt} = +254{cm}$, and since \TeX\ works with scaled points where there are $2^{16}$ +sp in a point, \TeX\ sets +$|num|/|den|=(254\cdot10^5)/(7227\cdot2^{16})=25400000/473628672$. +@^sp@> + +The |mag| parameter is what \TeX\ calls \.{\\mag}, i.e., 1000 times the +desired magnification. The actual fraction by which dimensions are +multiplied is therefore $|mag|\cdot|num|/1000|den|$. Note that if a \TeX\ +source document does not call for any `\.{true}' dimensions, and if you +change it only by specifying a different \.{\\mag} setting, the \.{DVI} +file that \TeX\ creates will be completely unchanged except for the value +of |mag| in the preamble and postamble. (Fancy \.{DVI}-reading programs allow +users to override the |mag|~setting when a \.{DVI} file is being printed.) + +Finally, |k| and |x| allow the \.{DVI} writer to include a comment, which is not +interpreted further. The length of comment |x| is |k|, where |0<=k<256|. + + +@c +#define id_byte 2 /* identifies the kind of \.{DVI} files described here */ + +@ Font definitions for a given font number |k| contain further parameters +$$\hbox{|c[4]| |s[4]| |d[4]| |a[1]| |l[1]| |n[a+l]|.}$$ +The four-byte value |c| is the check sum that \TeX\ found in the \.{TFM} +file for this font; |c| should match the check sum of the font found by +programs that read this \.{DVI} file. +@^check sum@> + +Parameter |s| contains a fixed-point scale factor that is applied to +the character widths in font |k|; font dimensions in \.{TFM} files and +other font files are relative to this quantity, which is called the +``at size'' elsewhere in this documentation. The value of |s| is +always positive and less than $2^{27}$. It is given in the same units +as the other \.{DVI} dimensions, i.e., in sp when \TeX82 has made the +file. Parameter |d| is similar to |s|; it is the ``design size,'' and +(like~|s|) it is given in \.{DVI} units. Thus, font |k| is to be used +at $|mag|\cdot s/1000d$ times its normal size. + +The remaining part of a font definition gives the external name of the font, +which is an ASCII string of length |a+l|. The number |a| is the length +of the ``area'' or directory, and |l| is the length of the font name itself; +the standard local system font area is supposed to be used when |a=0|. +The |n| field contains the area in its first |a| bytes. + +Font definitions must appear before the first use of a particular font number. +Once font |k| is defined, it must not be defined again; however, we +shall see below that font definitions appear in the postamble as well as +in the pages, so in this sense each font number is defined exactly twice, +if at all. Like |nop| commands, font definitions can +appear before the first |bop|, or between an |eop| and a |bop|. + +@ Sometimes it is desirable to make horizontal or vertical rules line up +precisely with certain features in characters of a font. It is possible to +guarantee the correct matching between \.{DVI} output and the characters +generated by \MF\ by adhering to the following principles: (1)~The \MF\ +characters should be positioned so that a bottom edge or left edge that is +supposed to line up with the bottom or left edge of a rule appears at the +reference point, i.e., in row~0 and column~0 of the \MF\ raster. This +ensures that the position of the rule will not be rounded differently when +the pixel size is not a perfect multiple of the units of measurement in +the \.{DVI} file. (2)~A typeset rule of height $a>0$ and width $b>0$ +should be equivalent to a \MF-generated character having black pixels in +precisely those raster positions whose \MF\ coordinates satisfy +|0<=x<@t$\alpha$@>b| and |0<=y<@t$\alpha$@>a|, where $\alpha$ is the number +of pixels per \.{DVI} unit. +@:METAFONT}{\MF@> +@^alignment of rules with characters@> +@^rules aligning with characters@> + +@ The last page in a \.{DVI} file is followed by `|post|'; this command +introduces the postamble, which summarizes important facts that \TeX\ has +accumulated about the file, making it possible to print subsets of the data +with reasonable efficiency. The postamble has the form +$$\vbox{\halign{\hbox{#\hfil}\cr + |post| |p[4]| |num[4]| |den[4]| |mag[4]| |l[4]| |u[4]| |s[2]| |t[2]|\cr + $\langle\,$font definitions$\,\rangle$\cr + |post_post| |q[4]| |i[1]| 223's$[{\G}4]$\cr}}$$ +Here |p| is a pointer to the final |bop| in the file. The next three +parameters, |num|, |den|, and |mag|, are duplicates of the quantities that +appeared in the preamble. + +Parameters |l| and |u| give respectively the height-plus-depth of the tallest +page and the width of the widest page, in the same units as other dimensions +of the file. These numbers might be used by a \.{DVI}-reading program to +position individual ``pages'' on large sheets of film or paper; however, +the standard convention for output on normal size paper is to position each +page so that the upper left-hand corner is exactly one inch from the left +and the top. Experience has shown that it is unwise to design \.{DVI}-to-printer +software that attempts cleverly to center the output; a fixed position of +the upper left corner is easiest for users to understand and to work with. +Therefore |l| and~|u| are often ignored. + +Parameter |s| is the maximum stack depth (i.e., the largest excess of +|push| commands over |pop| commands) needed to process this file. Then +comes |t|, the total number of pages (|bop| commands) present. + +The postamble continues with font definitions, which are any number of +\\{fnt\_def} commands as described above, possibly interspersed with |nop| +commands. Each font number that is used in the \.{DVI} file must be defined +exactly twice: Once before it is first selected by a \\{fnt} command, and once +in the postamble. + +@ The last part of the postamble, following the |post_post| byte that +signifies the end of the font definitions, contains |q|, a pointer to the +|post| command that started the postamble. An identification byte, |i|, +comes next; this currently equals~2, as in the preamble. + +The |i| byte is followed by four or more bytes that are all equal to +the decimal number 223 (i.e., '337 in octal). \TeX\ puts out four to seven of +these trailing bytes, until the total length of the file is a multiple of +four bytes, since this works out best on machines that pack four bytes per +word; but any number of 223's is allowed, as long as there are at least four +of them. In effect, 223 is a sort of signature that is added at the very end. +@^Fuchs, David Raymond@> + +This curious way to finish off a \.{DVI} file makes it feasible for +\.{DVI}-reading programs to find the postamble first, on most computers, +even though \TeX\ wants to write the postamble last. Most operating +systems permit random access to individual words or bytes of a file, so +the \.{DVI} reader can start at the end and skip backwards over the 223's +until finding the identification byte. Then it can back up four bytes, read +|q|, and move to byte |q| of the file. This byte should, of course, +contain the value 248 (|post|); now the postamble can be read, so the +\.{DVI} reader can discover all the information needed for typesetting the +pages. Note that it is also possible to skip through the \.{DVI} file at +reasonably high speed to locate a particular page, if that proves +desirable. This saves a lot of time, since \.{DVI} files used in production +jobs tend to be large. + +Unfortunately, however, standard \PASCAL\ does not include the ability to +@^system dependencies@> +access a random position in a file, or even to determine the length of a file. +Almost all systems nowadays provide the necessary capabilities, so \.{DVI} +format has been designed to work most efficiently with modern operating systems. +But if \.{DVI} files have to be processed under the restrictions of standard +\PASCAL, one can simply read them from front to back, since the necessary +header information is present in the preamble and in the font definitions. +(The |l| and |u| and |s| and |t| parameters, which appear only in the +postamble, are ``frills'' that are handy but not absolutely necessary.) + + +@* \[32] Shipping pages out. +After considering \TeX's eyes and stomach, we come now to the bowels. +@^bowels@> + +The |ship_out| procedure is given a pointer to a box; its mission is +to describe that box in \.{DVI} form, outputting a ``page'' to |dvi_file|. +The \.{DVI} coordinates $(h,v)=(0,0)$ should correspond to the upper left +corner of the box being shipped. + +Since boxes can be inside of boxes inside of boxes, the main work of +|ship_out| is done by two mutually recursive routines, |hlist_out| +and |vlist_out|, which traverse the hlists and vlists inside of horizontal +and vertical boxes. + +As individual pages are being processed, we need to accumulate +information about the entire set of pages, since such statistics must be +reported in the postamble. The global variables |total_pages|, |max_v|, +|max_h|, |max_push|, and |last_bop| are used to record this information. + +The variable |doing_leaders| is |true| while leaders are being output. +The variable |dead_cycles| contains the number of times an output routine +has been initiated since the last |ship_out|. + +A few additional global variables are also defined here for use in +|vlist_out| and |hlist_out|. They could have been local variables, but +that would waste stack space when boxes are deeply nested, since the +values of these variables are not needed during recursive calls. +@^recursion@> + +@c +int total_pages = 0; /* the number of pages that have been shipped out */ +scaled max_v = 0; /* maximum height-plus-depth of pages shipped so far */ +scaled max_h = 0; /* maximum width of pages shipped so far */ +int max_push = 0; /* deepest nesting of |push| commands encountered so far */ +int last_bop = -1; /* location of previous |bop| in the \.{DVI} output */ +int dead_cycles = 0; /* recent outputs that didn't ship anything out */ +boolean doing_leaders = false; /* are we inside a leader box? */ +int c, f; /* character and font in current |char_node| */ +int oval, ocmd; /* used by |out_cmd| for generating |set|, |fnt| and |fnt_def| commands */ +pointer g; /* current glue specification */ +int lq, lr; /* quantities used in calculations for leaders */ +int cur_s = -1; /* current depth of output box nesting, initially $-1$ */ + +@ The \.{DVI} bytes are output to a buffer instead of being written directly +to the output file. This makes it possible to reduce the overhead of +subroutine calls, thereby measurably speeding up the computation, since +output of \.{DVI} bytes is part of \TeX's inner loop. And it has another +advantage as well, since we can change instructions in the buffer in order to +make the output more compact. For example, a `|down2|' command can be +changed to a `|y2|', thereby making a subsequent `|y0|' command possible, +saving two bytes. + +The output buffer is divided into two parts of equal size; the bytes found +in |dvi_buf[0..half_buf-1]| constitute the first half, and those in +|dvi_buf[half_buf..dvi_buf_size-1]| constitute the second. The global +variable |dvi_ptr| points to the position that will receive the next +output byte. When |dvi_ptr| reaches |dvi_limit|, which is always equal +to one of the two values |half_buf| or |dvi_buf_size|, the half buffer that +is about to be invaded next is sent to the output and |dvi_limit| is +changed to its other value. Thus, there is always at least a half buffer's +worth of information present, except at the very beginning of the job. + +Bytes of the \.{DVI} file are numbered sequentially starting with 0; +the next byte to be generated will be number |dvi_offset+dvi_ptr|. +A byte is present in the buffer only if its number is |>=dvi_gone|. + +Some systems may find it more efficient to make |dvi_buf| a |packed| +array, since output of four bytes at once may be facilitated. +@^system dependencies@> + + +@ Initially the buffer is all in one piece; we will output half of it only +after it first fills up. + +@c +int dvi_buf_size = 800; /* size of the output buffer; must be a multiple of 8 */ +eight_bits *dvi_buf; /* buffer for \.{DVI} output */ +dvi_index half_buf = 0; /* half of |dvi_buf_size| */ +dvi_index dvi_limit = 0; /* end of the current half buffer */ +dvi_index dvi_ptr = 0; /* the next available buffer address */ +int dvi_offset = 0; /* |dvi_buf_size| times the number of times the output buffer has been fully emptied */ +int dvi_gone = 0; /* the number of bytes already output to |dvi_file| */ + +@ The actual output of |dvi_buf[a..b]| to |dvi_file| is performed by calling +|write_dvi(a,b)|. For best results, this procedure should be optimized to +run as fast as possible on each particular system, since it is part of +\TeX's inner loop. It is safe to assume that |a| and |b+1| will both be +multiples of 4 when |write_dvi(a,b)| is called; therefore it is possible on +many machines to use efficient methods to pack four bytes per word and to +output an array of words with one system call. +@^system dependencies@> +@^inner loop@> +@^defecation@> + +@c +void write_dvi(dvi_index a, dvi_index b) +{ + dvi_index k; + for (k = a; k <= b; k++) + fputc(dvi_buf[k], static_pdf->file); +} + +/* outputs half of the buffer */ +void dvi_swap(void) +{ + if (dvi_limit == dvi_buf_size) { + write_dvi(0, half_buf - 1); + dvi_limit = half_buf; + dvi_offset = dvi_offset + dvi_buf_size; + dvi_ptr = 0; + } else { + write_dvi(half_buf, dvi_buf_size - 1); + dvi_limit = dvi_buf_size; + } + dvi_gone = dvi_gone + half_buf; +} + +@ The |dvi_four| procedure outputs four bytes in two's complement notation, +without risking arithmetic overflow. + +@c +void dvi_four(int x) +{ + if (x >= 0) { + dvi_out(x / 0100000000); + } else { + x = x + 010000000000; + x = x + 010000000000; + dvi_out((x / 0100000000) + 128); + } + x = x % 0100000000; + dvi_out(x / 0200000); + x = x % 0200000; + dvi_out(x / 0400); + dvi_out(x % 0400); +} + +@ +A mild optimization of the output is performed by the |dvi_pop| +routine, which issues a |pop| unless it is possible to cancel a +`|push| |pop|' pair. The parameter to |dvi_pop| is the byte address +following the old |push| that matches the new |pop|. + + +@c +void dvi_push(void) +{ + dvi_out(push); +} + +void dvi_pop(int l) +{ + if ((l == dvi_offset + dvi_ptr) && (dvi_ptr > 0)) + decr(dvi_ptr); + else + dvi_out(pop); +} + +@ Here's a procedure that outputs a font definition. $\Omega$ allows +more than 256 different fonts per job, so the right font definition +command must be selected. + +@c +void out_cmd(void) +{ + if ((oval < 0x100) && (oval >= 0)) { + if ((ocmd != set1) || (oval > 127)) { + if ((ocmd == fnt1) && (oval < 64)) + oval += fnt_num_0; + else + dvi_out(ocmd); + } + } else { + if ((oval < 0x10000) && (oval >= 0)) { + dvi_out(ocmd + 1); + } else { + if ((oval < 0x1000000) && (oval >= 0)) { + dvi_out(ocmd + 2); + } else { + dvi_out(ocmd + 3); + if (oval >= 0) { + dvi_out(oval / 0x1000000); + } else { + oval += 0x40000000; + oval += 0x40000000; + dvi_out((oval / 0x1000000) + 128); + oval = oval % 0x1000000; + } + dvi_out(oval / 0x10000); + oval = oval % 0x10000; + } + dvi_out(oval / 0x10000); + oval = oval % 0x10000; + } + dvi_out(oval / 0x100); + oval = oval % 0x100; + } + dvi_out(oval); +} + +void dvi_font_def(internal_font_number f) +{ + char *fa; + oval = f - 1; + ocmd = fnt_def1; + out_cmd(); + dvi_out(font_check_0(f)); + dvi_out(font_check_1(f)); + dvi_out(font_check_2(f)); + dvi_out(font_check_3(f)); + dvi_four(font_size(f)); + dvi_four(font_dsize(f)); + dvi_out(0); /* |font_area(f)| is unused */ + dvi_out(strlen(font_name(f))); + /* Output the font name whose internal number is |f| */ + fa = font_name(f); + while (*fa != '\0') { + dvi_out(*fa++); + } +} + +@ Versions of \TeX\ intended for small computers might well choose to omit +the ideas in the next few parts of this program, since it is not really +necessary to optimize the \.{DVI} code by making use of the |w0|, |x0|, +|y0|, and |z0| commands. Furthermore, the algorithm that we are about to +describe does not pretend to give an optimum reduction in the length +of the \.{DVI} code; after all, speed is more important than compactness. +But the method is surprisingly effective, and it takes comparatively little +time. + +We can best understand the basic idea by first considering a simpler problem +that has the same essential characteristics. Given a sequence of digits, +say $3\,1\,4\,1\,5\,9\,2\,6\,5\,3\,5\,8\,9$, we want to assign subscripts +$d$, $y$, or $z$ to each digit so as to maximize the number of ``$y$-hits'' +and ``$z$-hits''; a $y$-hit is an instance of two appearances of the same +digit with the subscript $y$, where no $y$'s intervene between the two +appearances, and a $z$-hit is defined similarly. For example, the sequence +above could be decorated with subscripts as follows: +$$3_z\,1_y\,4_d\,1_y\,5_y\,9_d\,2_d\,6_d\,5_y\,3_z\,5_y\,8_d\,9_d.$$ +There are three $y$-hits ($1_y\ldots1_y$ and $5_y\ldots5_y\ldots5_y$) and +one $z$-hit ($3_z\ldots3_z$); there are no $d$-hits, since the two appearances +of $9_d$ have $d$'s between them, but we don't count $d$-hits so it doesn't +matter how many there are. These subscripts are analogous to the \.{DVI} +commands called \\{down}, $y$, and $z$, and the digits are analogous to +different amounts of vertical motion; a $y$-hit or $z$-hit corresponds to +the opportunity to use the one-byte commands |y0| or |z0| in a \.{DVI} file. + +\TeX's method of assigning subscripts works like this: Append a new digit, +say $\delta$, to the right of the sequence. Now look back through the +sequence until one of the following things happens: (a)~You see +$\delta_y$ or $\delta_z$, and this was the first time you encountered a +$y$ or $z$ subscript, respectively. Then assign $y$ or $z$ to the new +$\delta$; you have scored a hit. (b)~You see $\delta_d$, and no $y$ +subscripts have been encountered so far during this search. Then change +the previous $\delta_d$ to $\delta_y$ (this corresponds to changing a +command in the output buffer), and assign $y$ to the new $\delta$; it's +another hit. (c)~You see $\delta_d$, and a $y$ subscript has been seen +but not a $z$. Change the previous $\delta_d$ to $\delta_z$ and assign +$z$ to the new $\delta$. (d)~You encounter both $y$ and $z$ subscripts +before encountering a suitable $\delta$, or you scan all the way to the +front of the sequence. Assign $d$ to the new $\delta$; this assignment may +be changed later. + +The subscripts $3_z\,1_y\,4_d\ldots\,$ in the example above were, in fact, +produced by this procedure, as the reader can verify. (Go ahead and try it.) + +@ In order to implement such an idea, \TeX\ maintains a stack of pointers +to the \\{down}, $y$, and $z$ commands that have been generated for the +current page. And there is a similar stack for \\{right}, |w|, and |x| +commands. These stacks are called the down stack and right stack, and their +top elements are maintained in the variables |down_ptr| and |right_ptr|. + +Each entry in these stacks contains four fields: The |width| field is +the amount of motion down or to the right; the |location| field is the +byte number of the \.{DVI} command in question (including the appropriate +|dvi_offset|); the |vlink| field points to the next item below this one +on the stack; and the |vinfo| field encodes the options for possible change +in the \.{DVI} command. + +@c +#define location(A) varmem[(A)+1].cint /* \.{DVI} byte number for a movement command */ + +halfword down_ptr = null, right_ptr = null; /* heads of the down and right stacks */ + +@ Here is a subroutine that produces a \.{DVI} command for some specified +downward or rightward motion. It has two parameters: |w| is the amount +of motion, and |o| is either |down1| or |right1|. We use the fact that +the command codes have convenient arithmetic properties: |y1-down1=w1-right1| +and |z1-down1=x1-right1|. + +@c +void movement(scaled w, eight_bits o) +{ + small_number mstate; /* have we seen a |y| or |z|? */ + halfword p, q; /* current and top nodes on the stack */ + int k; /* index into |dvi_buf|, modulo |dvi_buf_size| */ + if (false) { /* TODO: HUH? */ + q = new_node(movement_node, 0); /* new node for the top of the stack */ + width(q) = w; + location(q) = dvi_offset + dvi_ptr; + if (o == down1) { + vlink(q) = down_ptr; + down_ptr = q; + } else { + vlink(q) = right_ptr; + right_ptr = q; + } + /* Look at the other stack entries until deciding what sort of \.{DVI} command + to generate; |goto found| if node |p| is a ``hit'' */ + p = vlink(q); + mstate = none_seen; + while (p != null) { + if (width(p) == w) { + /* Consider a node with matching width;|goto found| if it's a hit */ + /* We might find a valid hit in a |y| or |z| byte that is already gone + from the buffer. But we can't change bytes that are gone forever; ``the + moving finger writes, $\ldots\,\,$.'' */ + + switch (mstate + vinfo(p)) { + case none_seen + yz_OK: + case none_seen + y_OK: + case z_seen + yz_OK: + case z_seen + y_OK: + if (location(p) < dvi_gone) { + goto NOT_FOUND; + } else { + /* Change buffered instruction to |y| or |w| and |goto found| */ + k = location(p) - dvi_offset; + if (k < 0) + k = k + dvi_buf_size; + dvi_buf[k] = (eight_bits) (dvi_buf[k] + y1 - down1); + vinfo(p) = y_here; + goto FOUND; + } + break; + case none_seen + z_OK: + case y_seen + yz_OK: + case y_seen + z_OK: + if (location(p) < dvi_gone) { + goto NOT_FOUND; + } else { + /* Change buffered instruction to |z| or |x| and |goto found| */ + k = location(p) - dvi_offset; + if (k < 0) + k = k + dvi_buf_size; + dvi_buf[k] = (eight_bits) (dvi_buf[k] + z1 - down1); + vinfo(p) = z_here; + goto FOUND; + } + break; + case none_seen + y_here: + case none_seen + z_here: + case y_seen + z_here: + case z_seen + y_here: + goto FOUND; + break; + default: + break; + } + } else { + switch (mstate + vinfo(p)) { + case none_seen + y_here: + mstate = y_seen; + break; + case none_seen + z_here: + mstate = z_seen; + break; + case y_seen + z_here: + case z_seen + y_here: + goto NOT_FOUND; + break; + default: + break; + } + } + p = vlink(p); + } + } + NOT_FOUND: + /* Generate a |down| or |right| command for |w| and |return| */ + if (abs(w) >= 040000000) { + dvi_out(o + 3); /* |down4| or |right4| */ + dvi_four(w); + return; + } + if (abs(w) >= 0100000) { + dvi_out(o + 2); /* |down3| or |right3| */ + if (w < 0) + w = w + 0100000000; + dvi_out(w / 0200000); + w = w % 0200000; + goto TWO; + } + if (abs(w) >= 0200) { + dvi_out(o + 1); /* |down2| or |right2| */ + if (w < 0) + w = w + 0200000; + goto TWO; + } + dvi_out(o); /* |down1| or |right1| */ + if (w < 0) + w = w + 0400; + goto ONE; + TWO: + dvi_out(w / 0400); + ONE: + dvi_out(w % 0400); + return; + FOUND: + /* Generate a |y0| or |z0| command in order to reuse a previous appearance of~|w| */ + /* The program below removes movement nodes that are introduced after a |push|, + before it outputs the corresponding |pop|. */ + /* + When the |movement| procedure gets to the label |found|, the value of + |vinfo(p)| will be either |y_here| or |z_here|. If it is, say, |y_here|, + the procedure generates a |y0| command (or a |w0| command), and marks + all |vinfo| fields between |q| and |p| so that |y| is not OK in that range. + */ + vinfo(q) = vinfo(p); + if (vinfo(q) == y_here) { + dvi_out(o + y0 - down1); /* |y0| or |w0| */ + while (vlink(q) != p) { + q = vlink(q); + switch (vinfo(q)) { + case yz_OK: + vinfo(q) = z_OK; + break; + case y_OK: + vinfo(q) = d_fixed; + break; + default: + break; + } + } + } else { + dvi_out(o + z0 - down1); /* |z0| or |x0| */ + while (vlink(q) != p) { + q = vlink(q); + switch (vinfo(q)) { + case yz_OK: + vinfo(q) = y_OK; + break; + case z_OK: + vinfo(q) = d_fixed; + break; + default: + break; + } + } + } +} + +@ In case you are wondering when all the movement nodes are removed from +\TeX's memory, the answer is that they are recycled just before +|hlist_out| and |vlist_out| finish outputting a box. This restores the +down and right stacks to the state they were in before the box was output, +except that some |vinfo|'s may have become more restrictive. + + +@c +/* delete movement nodes with |location>=l| */ +void prune_movements(int l) +{ + pointer p; /* node being deleted */ + while (down_ptr != null) { + if (location(down_ptr) < l) + break; + p = down_ptr; + down_ptr = vlink(p); + flush_node(p); + } + while (right_ptr != null) { + if (location(right_ptr) < l) + return; + p = right_ptr; + right_ptr = vlink(p); + flush_node(p); + } +} + +scaledpos dvi; /* a \.{DVI} position in page coordinates, in sync with DVI file */ + +scaledpos cur_page_size; + +@ When |hlist_out| is called, its duty is to output the box represented +by the |hlist_node| pointed to by |temp_ptr|. The reference point of that +box has coordinates |(cur.h,cur.v)|. + +Similarly, when |vlist_out| is called, its duty is to output the box represented +by the |vlist_node| pointed to by |temp_ptr|. The reference point of that +box has coordinates |(cur.h,cur.v)|. +@^recursion@> + +@ The recursive procedures |hlist_out| and |vlist_out| each have a local variable +|save_dvi| to hold the value of |dvi| just before +entering a new level of recursion. In effect, the value of |save_dvi| +on \TeX's run-time stack corresponds to the values of |h| and |v| +that a \.{DVI}-reading program will push onto its coordinate stack. + +@c +void dvi_place_rule(PDF pdf, halfword q, scaledpos size) +{ + (void) q; + synch_dvi_with_pos(pdf->posstruct->pos); + if (textdir_is_L(pdf->posstruct->dir)) { + dvi_out(set_rule); /* movement optimization for |dir_*L*| */ + dvi.h += size.h; + } else + dvi_out(put_rule); + dvi_four(size.v); + dvi_four(size.h); +} + +void dvi_place_glyph(PDF pdf, internal_font_number f, int c) +{ + scaled_whd ci; + synch_dvi_with_pos(pdf->posstruct->pos); + if (f != pdf->f_cur) { + /* Change font |f_cur| to |f| */ + if (!font_used(f)) { + dvi_font_def(f); + set_font_used(f, true); + } + oval = f - 1; + ocmd = fnt1; + out_cmd(); + pdf->f_cur = f; + } + if (textdir_is_L(pdf->posstruct->dir)) { + ci = get_charinfo_whd(f, c); + dvi_set(c, ci.wd); /* movement optimization for |dir_*L*| */ + } else + dvi_put(c); +} + +void dvi_special(PDF pdf, halfword p) +{ + int old_setting; /* holds print |selector| */ + unsigned k; /* index into |cur_string| */ + synch_dvi_with_pos(pdf->posstruct->pos); + old_setting = selector; + selector = new_string; + show_token_list(token_link(write_tokens(p)), null, -1); + selector = old_setting; + if (cur_length < 256) { + dvi_out(xxx1); + dvi_out(cur_length); + } else { + dvi_out(xxx4); + dvi_four((int) cur_length); + } + for (k = 0; k < cur_length; k++) + dvi_out(cur_string[k]); + cur_length = 0; /* erase the string */ +} + +@ The final line of this routine is slightly subtle; at least, the author +didn't think about it until getting burnt! There is a used-up token list +@^Knuth, Donald Ervin@> +on the stack, namely the one that contained |end_write_token|. (We +insert this artificial `\.{\\endwrite}' to prevent runaways, as explained +above.) If it were not removed, and if there were numerous writes on a +single page, the stack would overflow. + +@c +/* TODO: keep track of this value */ +#define end_write_token cs_token_flag+end_write + +void expand_macros_in_tokenlist(halfword p) +{ + int old_mode; /* saved |mode| */ + pointer q, r; /* temporary variables for list manipulation */ + q = get_avail(); + token_info(q) = right_brace_token + '}'; + r = get_avail(); + token_link(q) = r; + token_info(r) = end_write_token; + begin_token_list(q, inserted); + begin_token_list(write_tokens(p), write_text); + q = get_avail(); + token_info(q) = left_brace_token + '{'; + begin_token_list(q, inserted); + /* now we're ready to scan + `\.\{$\langle\,$token list$\,\rangle$\.{\} \\endwrite}' */ + old_mode = mode; + mode = 0; + /* disable \.{\\prevdepth}, \.{\\spacefactor}, \.{\\lastskip}, \.{\\prevgraf} */ + cur_cs = write_loc; + q = scan_toks(false, true); /* expand macros, etc. */ + get_token(); + if (cur_tok != end_write_token) { + /* Recover from an unbalanced write command */ + const char *hlp[] = { + "On this page there's a \\write with fewer real {'s than }'s.", + "I can't handle that very well; good luck.", NULL + }; + tex_error("Unbalanced write command", hlp); + do { + get_token(); + } while (cur_tok != end_write_token); + } + mode = old_mode; + end_token_list(); /* conserve stack space */ +} + +void write_out(halfword p) +{ + int old_setting; /* holds print |selector| */ + int j; /* write stream number */ + boolean clobbered; /* system string is ok? */ + int ret; /* return value from |runsystem| */ + char *s, *ss; /* line to be written, as a C string */ + int callback_id; + int lua_retval; + expand_macros_in_tokenlist(p); + old_setting = selector; + j = write_stream(p); + if (j == 18) { + selector = new_string; + } else if (write_open[j]) { + selector = j; + } else { /* write to the terminal if file isn't open */ + if ((j == 17) && (selector == term_and_log)) + selector = log_only; + tprint_nl(""); + } + s = tokenlist_to_cstring(def_ref, false, NULL); + if (selector < no_print) { /* selector is a file */ + /* fix up the output buffer using callbacks */ + callback_id = callback_defined(process_output_buffer_callback); + if (callback_id > 0) { + lua_retval = run_callback(callback_id, "S->S", s, &ss); + if ((lua_retval == true) && (ss != NULL)) + s = ss; + } + } + tprint(s); + print_ln(); + flush_list(def_ref); + if (j == 18) { + cur_string[cur_length] = '\0'; /* Convert newline to null. */ + if (tracing_online <= 0) + selector = log_only; /* Show what we're doing in the log file. */ + else + selector = term_and_log; /* Show what we're doing. */ + /* If the log file isn't open yet, we can only send output to the terminal. + Calling |open_log_file| from here seems to result in bad data in the log. + */ + if (!log_opened) + selector = term_only; + tprint_nl("runsystem("); + tprint((char *) cur_string); + tprint(")..."); + if (shellenabledp) { + clobbered = false; + if (strlen((char *) cur_string) != cur_length) + clobbered = true; + /* minimal checking: NUL not allowed in argument string of |system|() */ + if (clobbered) { + tprint("clobbered"); + } else { + /* We have the command. See if we're allowed to execute it, + and report in the log. We don't check the actual exit status of + the command, or do anything with the output. */ + ret = runsystem((char *) cur_string); + if (ret == -1) + tprint("quotation error in system command"); + else if (ret == 0) + tprint("disabled (restricted)"); + else if (ret == 1) + tprint("executed"); + else if (ret == 2) + tprint("executed safely (allowed)"); + } + } else { + tprint("disabled"); /* |shellenabledp| false */ + } + print_char('.'); + tprint_nl(""); + print_ln(); + cur_length = 0; /* erase the string */ + } + selector = old_setting; +} + +@ Here's an example of how these conventions are used. Whenever it is time to +ship out a box of stuff, we shall use the macro |ensure_dvi_open|. + +@c +void ensure_dvi_header_written(PDF pdf) +{ + unsigned l; + unsigned s; /* index into |str_pool| */ + int old_setting; /* saved |selector| setting */ + assert(pdf->o_mode == OMODE_DVI); + assert(pdf->o_state == ST_FILE_OPEN); + + if (half_buf == 0) { + half_buf = dvi_buf_size / 2; + dvi_limit = dvi_buf_size; + } + + dvi_out(pre); + dvi_out(id_byte); /* output the preamble */ + dvi_four(25400000); + dvi_four(473628672); /* conversion ratio for sp */ + prepare_mag(); + dvi_four(mag); /* magnification factor is frozen */ + if (output_comment) { + l = (unsigned) strlen(output_comment); + dvi_out(l); + for (s = 0; s <= l - 1; s++) + dvi_out(output_comment[s]); + } else { /* the default code is unchanged */ + old_setting = selector; + selector = new_string; + tprint(" LuaTeX output "); + print_int(int_par(year_code)); + print_char('.'); + print_two(int_par(month_code)); + print_char('.'); + print_two(int_par(day_code)); + print_char(':'); + print_two(int_par(time_code) / 60); + print_two(int_par(time_code) % 60); + selector = old_setting; + dvi_out(cur_length); + for (s = 0; s < cur_length; s++) + dvi_out(cur_string[s]); + cur_length = 0; + } +} + +void dvi_begin_page(PDF pdf) +{ + int k; + int page_loc; /* location of the current |bop| */ + ensure_output_state(pdf, ST_HEADER_WRITTEN); + /* Initialize variables as |ship_out| begins */ + page_loc = dvi_offset + dvi_ptr; + dvi_out(bop); + for (k = 0; k <= 9; k++) + dvi_four(count(k)); + dvi_four(last_bop); + last_bop = page_loc; +} + +void dvi_end_page(PDF pdf) +{ + (void) pdf; + dvi_out(eop); + +#ifdef IPC + if (ipcon > 0) { + if (dvi_limit == half_buf) { + write_dvi(half_buf, dvi_buf_size - 1); + fflush(static_pdf->file); + dvi_gone = dvi_gone + half_buf; + } + if (dvi_ptr > 0) { + write_dvi(0, dvi_ptr - 1); + fflush(static_pdf->file); + dvi_offset = dvi_offset + dvi_ptr; + dvi_gone = dvi_gone + dvi_ptr; + } + dvi_ptr = 0; + dvi_limit = dvi_buf_size; + ipcpage(dvi_gone); + } +#endif /* IPC */ +} + +@ At the end of the program, we must finish things off by writing the +post\-amble. If |total_pages=0|, the \.{DVI} file was never opened. +If |total_pages>=65536|, the \.{DVI} file will lie. And if +|max_push>=65536|, the user deserves whatever chaos might ensue. + +@c +void finish_dvi_file(PDF pdf, int version, int revision) +{ + int k; + boolean res; + int callback_id = callback_defined(stop_run_callback); + (void) version; + (void) revision; + while (cur_s > -1) { + if (cur_s > 0) { + dvi_out(pop); + } else { + dvi_out(eop); + incr(total_pages); + } + decr(cur_s); + } + if (total_pages == 0) { + if (callback_id == 0) + tprint_nl("No pages of output."); + else if (callback_id > 0) + res = run_callback(callback_id, "->"); + } else { + dvi_out(post); /* beginning of the postamble */ + dvi_four(last_bop); + last_bop = dvi_offset + dvi_ptr - 5; /* |post| location */ + dvi_four(25400000); + dvi_four(473628672); /* conversion ratio for sp */ + prepare_mag(); + dvi_four(mag); /* magnification factor */ + dvi_four(max_v); + dvi_four(max_h); + dvi_out(max_push / 256); + dvi_out(max_push % 256); + dvi_out((total_pages / 256) % 256); + dvi_out(total_pages % 256); + /* Output the font definitions for all fonts that were used */ + k = max_font_id(); + while (k > 0) { + if (font_used(k)) { + dvi_font_def(k); + } + decr(k); + } + + dvi_out(post_post); + dvi_four(last_bop); + dvi_out(id_byte); +#ifndef IPC + k = 4 + ((dvi_buf_size - dvi_ptr) % 4); /* the number of 223's */ +#else + k = 7 - ((3 + dvi_offset + dvi_ptr) % 4); /* the number of 223's */ +#endif + + while (k > 0) { + dvi_out(223); + decr(k); + } + /* Empty the last bytes out of |dvi_buf| */ + /* Here is how we clean out the buffer when \TeX\ is all through; |dvi_ptr| + will be a multiple of~4. */ + if (dvi_limit == half_buf) + write_dvi(half_buf, dvi_buf_size - 1); + if (dvi_ptr > 0) + write_dvi(0, dvi_ptr - 1); + + if (callback_id == 0) { + tprint_nl("Output written on "); + tprint(pdf->file_name); + tprint(" ("); + print_int(total_pages); + tprint(" page"); + if (total_pages != 1) + print_char('s'); + tprint(", "); + print_int(dvi_offset + dvi_ptr); + tprint(" bytes)."); + } else if (callback_id > 0) { + res = run_callback(callback_id, "->"); + } + close_file(pdf->file); + } +} |