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+%
+% This file is part of the Omega project, which
+% is based in the web2c distribution of TeX.
+%
+% Copyright (c) 1994--2000 John Plaice and Yannis Haralambous
+% applies only to the changes to the original tftopl.web.
+%
+% This program by D. E. Knuth is not copyrighted and can be used freely.
+% Version 0 was implemented in January 1982.
+% In February 1982 a new restriction on ligature steps was added.
+% In June 1982 the routines were divided into smaller pieces for IBM people,
+% and the result was designated "Version 1" in September 1982.
+% Slight changes were made in October, 1982, for version 0.6 of TeX.
+% Version 2 (July 1983) was released with TeX version 0.999.
+% Version 2.1 (September 1983) changed TEXINFO to FONTDIMEN.
+% Version 2.2 (February 1984) simplified decimal fraction output.
+% Version 2.3 (May 1984) fixed a bug when lh=17.
+% Version 2.4 (July 1984) fixed a bug involving unused ligature code.
+% Version 2.5 (September 1985) updated the standard codingscheme names.
+% Version 3 (October 1989) introduced new ligature capabilities.
+% Version 3.1 (November 1989) renamed z[] to lig_z[] for better portability.
+% Version 3.2 (February 2008) added a newline after a warning message.
+% Version 3.3 (January 2014) added a space to an error message (Breitenlohner),
+% and tests nl>lig_size not 4*lig_size (C. M. Connelly, Melissa O'Neill).
+
+% Version 1.0 of OFM2OPL (December 1995) allows one to read OFM files.
+% Version 1.11 (February 2000).
+% Version 1.12 (September 2009) various bug fixes by Peter Breitenlohner.
+% Version 1.13 (January 2014) more bug fixes.
+
+% Here is TeX material that gets inserted after \input webmac
+\def\hang{\hangindent 3em\indent\ignorespaces}
+\font\ninerm=cmr9
+\let\mc=\ninerm % medium caps for names like SAIL
+\def\PASCAL{Pascal}
+
+\def\(#1){} % this is used to make section names sort themselves better
+\def\9#1{} % this is used for sort keys in the index
+
+\def\title{OFM2OPL}
+\def\contentspagenumber{201}
+\def\topofcontents{\null
+ \titlefalse % include headline on the contents page
+ \def\rheader{\mainfont\hfil \contentspagenumber}
+ \vfill
+ \centerline{\titlefont The {\ttitlefont OFM2OPL} processor}
+ \vskip 15pt
+ \centerline{(Version 1.13, January 2014)}
+ \vfill}
+\def\botofcontents{\vfill
+ \centerline{\hsize 5in\baselineskip9pt
+ \vbox{\ninerm\noindent
+ The preparation of the original report
+ by D. E. Knuth
+ was supported in part by the National Science
+ Foundation under grants IST-8201926 and MCS-8300984,
+ and by the System Development Foundation. `\TeX' is a
+ trademark of the American Mathematical Society.}}}
+\pageno=\contentspagenumber \advance\pageno by 1
+
+@* Introduction.
+The \.{OFM2OPL} utility program converts $\Omega$ and \TeX\ font
+metric (``\.{TFM}'' and ``\.{OFM}'') files into equivalent
+property-list (``\.{PL}'' and ``\.{OPL}'') files. It also
+makes a thorough check of the given \.{TFM} or \.{OFM} file,
+using essentially the same algorithm as \TeX\ or $\Omega$. Thus
+if \TeX\ or $\Omega$ complains that a \.{TFM} or an \.{OFM}
+file is ``bad,'' this program will pinpoint the source or sources of
+badness. A \.{PL} or \.{OPL} file output by this program can be edited
+with a normal text editor, and the result can be converted back to \.{TFM}
+or \.{OFM} format using the companion program \.{OPL2OFM}.
+
+The first \.{TFtoPL} program was designed by Leo Guibas in the summer of
+1978. Contributions by Frank Liang, Doug Wyatt, and Lyle Ramshaw
+also had a significant effect on the evolution of the present code.
+
+Extensions for an enhanced ligature mechanism were added by
+D. E. Knuth in 1989.
+
+Extensions to handle extended font metric files (``\.{OFM}'') were
+added by John Plaice in December 1995 and January 1996, resulting in
+the new program \.{OFM2OPL}. In the following documentation, all
+unchanged references to the \.{TFtoPL} program and to \.{TFM} and
+\.{PL} files also apply to the \.{OFM2OPL} program and to \.{OFM}
+and \.{OPL} files.
+
+The |banner| string defined here should be changed whenever \.{OFM2OPL}
+gets modified.
+
+@d banner=='This is OFM2OPL, Version 1.13' {printed when the program starts}
+
+@ This program is written entirely in standard \PASCAL, except that
+it occasionally has lower case letters in strings that are output.
+Such letters can be converted to upper case if necessary. The input is read
+from |tfm_file|, and the output is written on |pl_file|; error messages and
+other remarks are written on the |output| file, which the user may
+choose to assign to the terminal if the system permits it.
+@^system dependencies@>
+
+The term |print| is used instead of |write| when this program writes on
+the |output| file, so that all such output can be easily deflected.
+
+@d print(#)==write(#)
+@d print_ln(#)==write_ln(#)
+
+@p program OFM2OPL(@!tfm_file,@!pl_file,@!output);
+label @<Labels in the outer block@>@/
+const @<Constants in the outer block@>@/
+type @<Types in the outer block@>@/
+var @<Globals in the outer block@>@/
+procedure initialize; {this procedure gets things started properly}
+ begin print_ln(banner);@/
+ @<Set initial values@>@/
+ end;
+
+@ If the program has to stop prematurely, it goes to the
+`|final_end|'.
+
+@d final_end=9999 {label for the end of it all}
+
+@<Labels...@>=final_end;
+
+@ The following parameters can be changed at compile time to extend or
+reduce \.{TFtoPL}'s capacity.
+
+@d char_max=@"FFFF
+@d xchar_max=char_max+1
+@d xxchar_max=xchar_max+1
+@d xxxchar_max=xxchar_max+1
+
+@<Constants...@>=
+@!tfm_size=2000000; {maximum length of |tfm| data, in bytes}
+@!lig_size=800000; {maximum length of |lig_kern| program, in words}
+@!hash_size=130003; {preferably a prime number, a bit larger than the number
+ of character pairs in lig/kern steps}
+@!hash_mult=16007; {another prime}
+@!max_char=char_max; {the largest character number in a font}
+@!xmax_char=xchar_max; {|max_char|+1}
+@!xxmax_char=xxchar_max;{|max_char|+2}
+@!xmax_label=80001;{must be greater than |max_lig_steps|}
+
+@ Here are some macros for common programming idioms.
+
+@d incr(#) == #:=#+1 {increase a variable by unity}
+@d decr(#) == #:=#-1 {decrease a variable by unity}
+@d do_nothing == {empty statement}
+
+@* Font metric data.
+The following description of \.{TFM} files is not sufficient for
+\.{OFM} files. The additional documentation necessary for the
+\.{OFM} files can be found in another file, such as the $\Omega$
+change files.
+
+The idea behind \.{TFM} files is that typesetting routines like \TeX\
+need a compact way to store the relevant information about several
+dozen fonts, and computer centers need a compact way to store the
+relevant information about several hundred fonts. \.{TFM} files are
+compact, and most of the information they contain is highly relevant,
+so they provide a solution to the problem.
+
+The information in a \.{TFM} file appears in a sequence of 8-bit bytes.
+Since the number of bytes is always a multiple of 4, we could
+also regard the file as a sequence of 32-bit words; but \TeX\ uses the
+byte interpretation, and so does \.{TFtoPL}. Note that the bytes
+are considered to be unsigned numbers.
+
+@<Glob...@>=
+@!tfm_file:packed file of 0..255;
+
+@ On some systems you may have to do something special to read a
+packed file of bytes. For example, the following code didn't work
+when it was first tried at Stanford, because packed files have to be
+opened with a special switch setting on the \PASCAL\ that was used.
+@^system dependencies@>
+
+@<Set init...@>=
+reset(tfm_file);
+
+@ The first 24 bytes (6 words) of a \.{TFM} file contain twelve 16-bit
+integers that give the lengths of the various subsequent portions
+of the file. These twelve integers are, in order:
+$$\vbox{\halign{\hfil#&$\null=\null$#\hfil\cr
+|@!lf|&length of the entire file, in words;\cr
+|@!lh|&length of the header data, in words;\cr
+|@!bc|&smallest character code in the font;\cr
+|@!ec|&largest character code in the font;\cr
+|@!nw|&number of words in the width table;\cr
+|@!nh|&number of words in the height table;\cr
+|@!nd|&number of words in the depth table;\cr
+|@!ni|&number of words in the italic correction table;\cr
+|@!nl|&number of words in the lig/kern table;\cr
+|@!nk|&number of words in the kern table;\cr
+|@!ne|&number of words in the extensible character table;\cr
+|@!np|&number of font parameter words.\cr}}$$
+They are all nonnegative and less than $2^{15}$. We must have |bc-1<=ec<=255|,
+|ne<=256|, and
+$$\hbox{|lf=6+lh+(ec-bc+1)+nw+nh+nd+ni+nl+nk+ne+np|.}$$
+Note that a font may contain as many as 256 characters (if |bc=0| and |ec=255|),
+and as few as 0 characters (if |bc=ec+1|).
+
+Incidentally, when two or more 8-bit bytes are combined to form an integer of
+16 or more bits, the most significant bytes appear first in the file.
+This is called BigEndian order.
+
+@<Glob...@>=
+@!ofm_level,
+@!nco,@!ncw,@!npc,@!nki,@!nwi,@!nkf,@!nwf,@!nkr,@!nwr,@!nkg,@!nwg,@!nkp,@!nwp,
+@!nkm,@!nwm,@!real_lf,@!nlw,@!neew,
+@!lf,@!lh,@!bc,@!ec,@!nw,@!nh,@!nd,@!ni,@!nl,@!nk,@!ne,@!np,@!font_dir:integer;
+ {subfile sizes}
+@!ofm_on:boolean;
+
+@ @<Set init...@>=
+ofm_on:=false; ofm_level:=-1; lf:=0; lh:=0;
+nco:=0; ncw:=0; npc:=0; bc:=0; ec:=0; nw:=0; nh:=0; nd:=0; ni:=0;
+nl:=0; nk:=0; ne:=0; np:=0;
+nki:=0; nwi:=0; nkf:=0; nwf:=0;
+nkm:=0; nwm:=0; real_lf:=0;
+nkr:=0; nwr:=0; nkg:=0; nwg:=0;
+nkp:=0; nwp:=0; font_dir:=0;
+
+@ The rest of the \.{TFM} file may be regarded as a sequence of ten data
+arrays having the informal specification
+$$\def\arr$[#1]#2${\&{array} $[#1]$ \&{of} #2}
+\vbox{\halign{\hfil\\{#}&$\,:\,$\arr#\hfil\cr
+header&|[0..lh-1]stuff|\cr
+char\_info&|[bc..ec]char_info_word|\cr
+width&|[0..nw-1]fix_word|\cr
+height&|[0..nh-1]fix_word|\cr
+depth&|[0..nd-1]fix_word|\cr
+italic&|[0..ni-1]fix_word|\cr
+lig\_kern&|[0..nl-1]lig_kern_command|\cr
+kern&|[0..nk-1]fix_word|\cr
+exten&|[0..ne-1]extensible_recipe|\cr
+param&|[1..np]fix_word|\cr}}$$
+The most important data type used here is a |@!fix_word|, which is
+a 32-bit representation of a binary fraction. A |fix_word| is a signed
+quantity, with the two's complement of the entire word used to represent
+negation. Of the 32 bits in a |fix_word|, exactly 12 are to the left of the
+binary point; thus, the largest |fix_word| value is $2048-2^{-20}$, and
+the smallest is $-2048$. We will see below, however, that all but one of
+the |fix_word| values will lie between $-16$ and $+16$.
+
+@ The first data array is a block of header information, which contains
+general facts about the font. The header must contain at least two words,
+and for \.{TFM} files to be used with Xerox printing software it must
+contain at least 18 words, allocated as described below. When different
+kinds of devices need to be interfaced, it may be necessary to add further
+words to the header block.
+
+\yskip\hang|header[0]| is a 32-bit check sum that \TeX\ will copy into the
+\.{DVI} output file whenever it uses the font. Later on when the \.{DVI}
+file is printed, possibly on another computer, the actual font that gets
+used is supposed to have a check sum that agrees with the one in the
+\.{TFM} file used by \TeX. In this way, users will be warned about
+potential incompatibilities. (However, if the check sum is zero in either
+the font file or the \.{TFM} file, no check is made.) The actual relation
+between this check sum and the rest of the \.{TFM} file is not important;
+the check sum is simply an identification number with the property that
+incompatible fonts almost always have distinct check sums.
+@^check sum@>
+
+\yskip\hang|header[1]| is a |fix_word| containing the design size of the
+font, in units of \TeX\ points (7227 \TeX\ points = 254 cm). This number
+must be at least 1.0; it is fairly arbitrary, but usually the design size
+is 10.0 for a ``10 point'' font, i.e., a font that was designed to look
+best at a 10-point size, whatever that really means. When a \TeX\ user
+asks for a font `\.{at} $\delta$ \.{pt}', the effect is to override the
+design size and replace it by $\delta$, and to multiply the $x$ and~$y$
+coordinates of the points in the font image by a factor of $\delta$
+divided by the design size. {\sl All other dimensions in the\/\ \.{TFM}
+file are |fix_word|\kern-1pt\ numbers in design-size units.} Thus, for example,
+the value of |param[6]|, one \.{em} or \.{\\quad}, is often the |fix_word|
+value $2^{20}=1.0$, since many fonts have a design size equal to one em.
+The other dimensions must be less than 16 design-size units in absolute
+value; thus, |header[1]| and |param[1]| are the only |fix_word| entries in
+the whole \.{TFM} file whose first byte might be something besides 0 or
+255. @^design size@>
+
+\yskip\hang|header[2..11]|, if present, contains 40 bytes that identify
+the character coding scheme. The first byte, which must be between 0 and
+39, is the number of subsequent ASCII bytes actually relevant in this
+string, which is intended to specify what character-code-to-symbol
+convention is present in the font. Examples are \.{ASCII} for standard
+ASCII, \.{TeX text} for fonts like \.{cmr10} and \.{cmti9}, \.{TeX math
+extension} for \.{cmex10}, \.{XEROX text} for Xerox fonts, \.{GRAPHIC} for
+special-purpose non-alphabetic fonts, \.{UNSPECIFIED} for the default case
+when there is no information. Parentheses should not appear in this name.
+(Such a string is said to be in {\mc BCPL} format.)
+@^coding scheme@>
+
+\yskip\hang|header[12..16]|, if present, contains 20 bytes that name the
+font family (e.g., \.{CMR} or \.{HELVETICA}), in {\mc BCPL} format.
+This field is also known as the ``font identifier.''
+@^family name@>
+@^font identifier@>
+
+\yskip\hang|header[17]|, if present, contains a first byte called the
+|seven_bit_safe_flag|, then two bytes that are ignored, and a fourth byte
+called the |face|. If the value of the fourth byte is less than 18, it has
+the following interpretation as a ``weight, slope, and expansion'': Add 0
+or 2 or 4 (for medium or bold or light) to 0 or 1 (for roman or italic) to
+0 or 6 or 12 (for regular or condensed or extended). For example, 13 is
+0+1+12, so it represents medium italic extended. A three-letter code
+(e.g., \.{MIE}) can be used for such |face| data.
+
+\yskip\hang|header[18..@twhatever@>]| might also be present; the individual
+words are simply called |header[18]|, |header[19]|, etc., at the moment.
+
+@ Next comes the |char_info| array, which contains one |char_info_word|
+per character. Each |char_info_word| contains six fields packed into
+four bytes as follows.
+
+\yskip\hang first byte: |width_index| (8 bits)\par
+\hang second byte: |height_index| (4 bits) times 16, plus |depth_index|
+ (4~bits)\par
+\hang third byte: |italic_index| (6 bits) times 4, plus |tag|
+ (2~bits)\par
+\hang fourth byte: |remainder| (8 bits)\par
+\yskip\noindent
+The actual width of a character is |width[width_index]|, in design-size
+units; this is a device for compressing information, since many characters
+have the same width. Since it is quite common for many characters
+to have the same height, depth, or italic correction, the \.{TFM} format
+imposes a limit of 16 different heights, 16 different depths, and
+64 different italic corrections.
+
+Incidentally, the relation |width[0]=height[0]=depth[0]=italic[0]=0|
+should always hold, so that an index of zero implies a value of zero.
+The |width_index| should never be zero unless the character does
+not exist in the font, since a character is valid if and only if it lies
+between |bc| and |ec| and has a nonzero |width_index|.
+
+@ The |tag| field in a |char_info_word| has four values that explain how to
+interpret the |remainder| field.
+
+\yskip\hang|tag=0| (|no_tag|) means that |remainder| is unused.\par
+\hang|tag=1| (|lig_tag|) means that this character has a ligature/kerning
+program starting at |lig_kern[remainder]|.\par
+\hang|tag=2| (|list_tag|) means that this character is part of a chain of
+characters of ascending sizes, and not the largest in the chain. The
+|remainder| field gives the character code of the next larger character.\par
+\hang|tag=3| (|ext_tag|) means that this character code represents an
+extensible character, i.e., a character that is built up of smaller pieces
+so that it can be made arbitrarily large. The pieces are specified in
+|exten[remainder]|.\par
+
+@d no_tag=0 {vanilla character}
+@d lig_tag=1 {character has a ligature/kerning program}
+@d list_tag=2 {character has a successor in a charlist}
+@d ext_tag=3 {character is extensible}
+
+@ The |lig_kern| array contains instructions in a simple programming language
+that explains what to do for special letter pairs. Each word is a
+|lig_kern_command| of four bytes.
+
+\yskip\hang first byte: |skip_byte|, indicates that this is the final program
+ step if the byte is 128 or more, otherwise the next step is obtained by
+ skipping this number of intervening steps.\par
+\hang second byte: |next_char|, ``if |next_char| follows the current character,
+ then perform the operation and stop, otherwise continue.''\par
+\hang third byte: |op_byte|, indicates a ligature step if less than~128,
+ a kern step otherwise.\par
+\hang fourth byte: |remainder|.\par
+\yskip\noindent
+In a kern step, an
+additional space equal to |kern[256*(op_byte-128)+remainder]| is inserted
+between the current character and |next_char|. This amount is
+often negative, so that the characters are brought closer together
+by kerning; but it might be positive.
+
+There are eight kinds of ligature steps, having |op_byte| codes $4a+2b+c$ where
+$0\le a\le b+c$ and $0\le b,c\le1$. The character whose code is
+|remainder| is inserted between the current character and |next_char|;
+then the current character is deleted if $b=0$, and |next_char| is
+deleted if $c=0$; then we pass over $a$~characters to reach the next
+current character (which may have a ligature/kerning program of its own).
+
+Notice that if $a=0$ and $b=1$, the current character is unchanged; if
+$a=b$ and $c=1$, the current character is changed but the next character is
+unchanged. \.{TFtoPL} will check to see that infinite loops are avoided.
+
+If the very first instruction of the |lig_kern| array has |skip_byte=255|,
+the |next_char| byte is the so-called right boundary character of this font;
+the value of |next_char| need not lie between |bc| and~|ec|.
+If the very last instruction of the |lig_kern| array has |skip_byte=255|,
+there is a special ligature/kerning program for a left boundary character,
+beginning at location |256*op_byte+remainder|.
+The interpretation is that \TeX\ puts implicit boundary characters
+before and after each consecutive string of characters from the same font.
+These implicit characters do not appear in the output, but they can affect
+ligatures and kerning.
+
+If the very first instruction of a character's |lig_kern| program has
+|skip_byte>128|, the program actually begins in location
+|256*op_byte+remainder|. This feature allows access to large |lig_kern|
+arrays, because the first instruction must otherwise
+appear in a location |<=255|.
+
+Any instruction with |skip_byte>128| in the |lig_kern| array must have
+|256*op_byte+remainder<nl|. If such an instruction is encountered during
+normal program execution, it denotes an unconditional halt; no ligature
+command is performed.
+
+@d stop_flag=128 {value indicating `\.{STOP}' in a lig/kern program}
+@d kern_flag=128 {op code for a kern step}
+
+@ Extensible characters are specified by an |extensible_recipe|,
+which consists of four bytes called |top|, |mid|,
+|bot|, and |rep| (in this order). These bytes are the character codes
+of individual pieces used to build up a large symbol.
+If |top|, |mid|, or |bot| are zero,
+they are not present in the built-up result. For example, an extensible
+vertical line is like an extensible bracket, except that the top and
+bottom pieces are missing.
+
+
+@ The final portion of a \.{TFM} file is the |param| array, which is another
+sequence of |fix_word| values.
+
+\yskip\hang|param[1]=@!slant| is the amount of italic slant, which is used
+to help position accents. For example, |slant=.25| means that when you go
+up one unit, you also go .25 units to the right. The |slant| is a pure
+number; it's the only |fix_word| other than the design size itself that is
+not scaled by the design size.
+
+\hang|param[2]=space| is the normal spacing between words in text.
+Note that character |" "| in the font need not have anything to do with
+blank spaces.
+
+\hang|param[3]=space_stretch| is the amount of glue stretching between words.
+
+\hang|param[4]=space_shrink| is the amount of glue shrinking between words.
+
+\hang|param[5]=x_height| is the height of letters for which accents don't
+have to be raised or lowered.
+
+\hang|param[6]=quad| is the size of one em in the font.
+
+\hang|param[7]=extra_space| is the amount added to |param[2]| at the
+ends of sentences.
+
+When the character coding scheme is \.{TeX math symbols}, the font is
+supposed to have 15 additional parameters called |num1|, |num2|, |num3|,
+|denom1|, |denom2|, |sup1|, |sup2|, |sup3|, |sub1|, |sub2|, |supdrop|,
+|subdrop|, |delim1|, |delim2|, and |axis_height|, respectively. When the
+character coding scheme is \.{TeX math extension}, the font is supposed to
+have six additional parameters called |default_rule_thickness| and
+|big_op_spacing1| through |big_op_spacing5|.
+
+@ So that is what \.{TFM} files hold. The next question is, ``What about
+\.{PL} files?'' A complete answer to that question appears in the
+documentation of the companion program, \.{PLtoTF}, so it will not
+be repeated here. Suffice it to say that a \.{PL} file is an ordinary
+\PASCAL\ text file, and that the output of \.{TFtoPL} uses only a
+subset of the possible constructions that might appear in a \.{PL} file.
+Furthermore, hardly anybody really wants to look at the formal
+definition of \.{PL} format, because it is almost self-explanatory when
+you see an example or two.
+
+@<Glob...@>=
+@!pl_file:text;
+
+@ @<Set init...@>=
+rewrite(pl_file);
+
+@* Unpacked representation.
+The first thing \.{TFtoPL} does is read the entire |tfm_file| into an array of
+bytes, |tfm[0..(4*lf-1)]|.
+
+@<Types...@>=
+@!byte=0..255; {unsigned eight-bit quantity}
+@!index=0..tfm_size; {address of a byte in |tfm|}
+@!char_type=0..char_max;
+@!xchar_type=0..xchar_max;
+@!xxchar_type=0..xxchar_max;
+@!xxxchar_type=0..xxxchar_max;
+
+@ @<Glob...@>=
+@!tfm:array [-1000..tfm_size] of byte; {the input data all goes here}
+ {the negative addresses avoid range checks for invalid characters}
+@!top_char,@!top_width,@!top_height,@!top_depth,@!top_italic:integer;
+@!start_ptr,@!check_sum,@!design_size,@!scheme,@!family,@!random_word:integer;
+@!header_length,@!char_ptr,@!copies,@!j:integer;
+
+@ The input may, of course, be all screwed up and not a \.{TFM} file
+at all. So we begin cautiously.
+
+@d abort(#)==begin print_ln(#);
+ print_ln('Sorry, but I can''t go on; are you sure this is a OFM?');
+ goto final_end;
+ end
+
+@<Read the whole input file@>=
+read(tfm_file,tfm[0]);
+if tfm[0]>127 then abort('The first byte of the input file exceeds 127!');
+@.The first byte...@>
+if eof(tfm_file) then abort('The input file is only one byte long!');
+@.The input...one byte long@>
+read(tfm_file,tfm[1]); lf:=tfm[0]*@'400+tfm[1];
+if lf=0 then
+ begin for i:=2 to 7 do
+ begin if eof(tfm_file) then
+ abort('The input file is too short to designate its length!');
+ read(tfm_file, tfm[i]);
+ end;
+ ofm_on := true; ofm_level := tfm[2]*@"100+tfm[3];
+ if ofm_level>1 then
+ abort('OFMLEVEL ',ofm_level:1,' not supported, must be 0 or 1!');
+@.OFMLEVEL...must be 0 or 1@>
+ if tfm[4]>127 then abort('The fifth byte of the input file exceeds 127!');
+@.The fifth byte...@>
+ lf := tfm[4]*@"1000000 + tfm[5]*@"10000 + tfm[6]*@"100 + tfm[7];
+ end
+else begin ofm_on := false;
+ end;
+case ofm_level of
+-1: begin start_ptr:=2; check_sum:=24; end;
+ 0: begin start_ptr:=8; check_sum:=56; end;
+ 1: begin start_ptr:=8; check_sum:=116; end;
+end;
+design_size:=check_sum+4;
+scheme:=design_size+4;
+family:=scheme+40;
+random_word:=family+20;
+if lf=0 then
+ abort('The file claims to have length zero, but that''s impossible!');
+@.The file claims...@>
+if 4*lf-1>tfm_size then abort('The file is bigger than I can handle!');
+@.The file is bigger...@>
+for tfm_ptr:=start_ptr to 4*lf-1 do
+ begin if eof(tfm_file) then
+ abort('The file has fewer bytes than it claims!');
+@.The file has fewer bytes...@>
+ read(tfm_file,tfm[tfm_ptr]);
+ end;
+if not eof(tfm_file) then
+ begin print_ln('There''s some extra junk at the end of the OFM file,');
+@.There's some extra junk...@>
+ print_ln('but I''ll proceed as if it weren''t there.');
+ end
+
+@ After the file has been read successfully, we look at the subfile sizes
+to see if they check out.
+
+@d eval_two_bytes(#)==begin if tfm[tfm_ptr]>127 then
+ abort('One of the subfile sizes is negative!');
+@.One of the subfile sizes...@>
+ #:=tfm[tfm_ptr]*@'400+tfm[tfm_ptr+1];
+ tfm_ptr:=tfm_ptr+2;
+ end
+@d eval_four_bytes(#)==begin if tfm[tfm_ptr]>127 then
+ abort('One of the subfile sizes is negative!');
+@.One of the subfile sizes...@>
+ #:=tfm[tfm_ptr]*@"1000000+tfm[tfm_ptr+1]*@"10000+
+ tfm[tfm_ptr+2]*@"100+tfm[tfm_ptr+3];
+ tfm_ptr:=tfm_ptr+4;
+ end
+
+@<Set subfile sizes |lh|, |bc|, \dots, |np|@>=
+begin
+if not ofm_on then begin
+ tfm_ptr:=2;
+ eval_two_bytes(lh);
+ eval_two_bytes(bc);
+ eval_two_bytes(ec);
+ eval_two_bytes(nw);
+ eval_two_bytes(nh);
+ eval_two_bytes(nd);
+ eval_two_bytes(ni);
+ eval_two_bytes(nl);
+ eval_two_bytes(nk);
+ eval_two_bytes(ne);
+ eval_two_bytes(np);
+ ncw:=(ec-bc+1);
+ nlw:=nl;
+ neew:=ne;
+ header_length:=6;
+ top_char:=255;
+ top_width:=255;
+ top_height:=15;
+ top_depth:=15;
+ top_italic:=63;
+ end
+else begin
+ tfm_ptr:=8;
+ eval_four_bytes(lh);
+ eval_four_bytes(bc);
+ eval_four_bytes(ec);
+ eval_four_bytes(nw);
+ eval_four_bytes(nh);
+ eval_four_bytes(nd);
+ eval_four_bytes(ni);
+ eval_four_bytes(nl);
+ eval_four_bytes(nk);
+ eval_four_bytes(ne);
+ eval_four_bytes(np);
+ eval_four_bytes(font_dir);
+ nlw:=2*nl;
+ neew:=2*ne;
+ top_char:=char_max;
+ top_width:=char_max;
+ top_height:=255;
+ top_depth:=255;
+ top_italic:=255;
+ if ofm_level=0 then begin
+ header_length:=14;
+ ncw:=2*(ec-bc+1);
+ end
+ else begin
+ header_length:=29;
+ eval_four_bytes(nco);
+ eval_four_bytes(ncw);
+ eval_four_bytes(npc);
+ eval_four_bytes(nki); {Kinds of font ivalues}
+ eval_four_bytes(nwi); {Words of font ivalues}
+ eval_four_bytes(nkf); {Kinds of font fvalues}
+ eval_four_bytes(nwf); {Words of font fvalues}
+ eval_four_bytes(nkm); {Kinds of font mvalues}
+ eval_four_bytes(nwm); {Words of font mvalues}
+ eval_four_bytes(nkr); {Kinds of font rules}
+ eval_four_bytes(nwr); {Words of font rules}
+ eval_four_bytes(nkg); {Kinds of font glues}
+ eval_four_bytes(nwg); {Words of font glues}
+ eval_four_bytes(nkp); {Kinds of font penalties}
+ eval_four_bytes(nwp); {Words of font penalties}
+ end;
+ end;
+if lf<>(header_length+lh+ncw+nw+nh+nd+ni+nlw+nk+neew+np+
+ nki+nwi+nkf+nwf+nkm+nwm+nkr+nwr+nkg+nwg+nkp+nwp) then
+ abort('Subfile sizes don''t add up to the stated total!');
+@.Subfile sizes don't add up...@>
+if lh<2 then abort('The header length is only ',lh:1,'!');
+@.The header length...@>
+if nl>lig_size then
+ abort('The lig/kern program is longer than I can handle!');
+@.The lig/kern program...@>
+if (bc>ec+1)or(ec>top_char) then abort('The character code range ',
+@.The character code range...@>
+ bc:1,'..',ec:1,' is illegal!');
+if ec>max_char then
+ abort('Character ',ec:1,'is too large. Ask a wizard to enlarge me.');
+if (nw=0)or(nh=0)or(nd=0)or(ni=0) then
+ abort('Incomplete subfiles for character dimensions!');
+@.Incomplete subfiles...@>
+if ne>(top_char+1) then abort('There are ',ne:1,' extensible recipes!');
+@.There are ... recipes@>
+end
+
+@ Once the input data successfully passes these basic checks,
+\.{TFtoPL} believes that it is a \.{TFM} file, and the conversion
+to \.{PL} format will take place. Access to the various subfiles
+is facilitated by computing the following base addresses. For example,
+the |char_info| for character |c| in a \.{TFM} file will start in location
+|4*(char_base+c)| of the |tfm| array.
+
+@<Globals...@>=
+@!ivalues_start,@!fvalues_start,@!mvalues_start,
+@!rules_start,@!glues_start,@!penalties_start:
+integer;
+@!ivalues_base,@!fvalues_base,@!mvalues_base,
+@!rules_base,@!glues_base,@!penalties_base:
+integer;
+@!char_base,@!width_base,@!height_base,@!depth_base,@!italic_base: integer;
+@!lig_kern_base,@!kern_base,@!exten_base,@!param_base:integer;
+ {base addresses for the subfiles}
+@!char_start:array [0..max_char] of integer;
+@!bytes_per_entry:integer;
+
+@ @<Compute the base addresses@>=
+begin
+ivalues_start:=header_length+lh;
+fvalues_start:=ivalues_start+nki;
+mvalues_start:=fvalues_start+nkf;
+rules_start:=mvalues_start+nkm;
+glues_start:=rules_start+nkr;
+penalties_start:=glues_start+nkg;
+ivalues_base:=penalties_start+nkp;
+fvalues_base:=ivalues_base+nwi;
+mvalues_base:=fvalues_base+nwf;
+rules_base:=mvalues_base+nwm;
+glues_base:=rules_base+nwr;
+penalties_base:=glues_base+nwg;
+char_base:=penalties_base+nwp;
+bytes_per_entry:=(12 + 2*npc) div 4 * 4;
+if not ofm_on then begin
+ for i:=bc to ec do begin
+ char_start[i]:=4*char_base+4*(i-bc);
+ end;
+ end
+else if ofm_level=0 then begin
+ for i:=bc to ec do begin
+ char_start[i]:=4*char_base+8*(i-bc);
+ end;
+ end
+else begin
+ char_ptr:=4*char_base;
+ i:=bc;
+ while i<=ec do begin
+ copies:=1+256*tfm[char_ptr+8]+tfm[char_ptr+9];
+ for j:=1 to copies do begin
+ char_start[i]:=char_ptr;
+ i:=i+1;
+ end;
+ char_ptr:=char_ptr + bytes_per_entry;
+ end;
+ if char_ptr<>(4*(char_base+ncw)) then
+ abort('Length of char info table does not correspond to specification');
+ end;
+width_base:=char_base+ncw;
+height_base:=width_base+nw;
+depth_base:=height_base+nh;
+italic_base:=depth_base+nd;
+lig_kern_base:=italic_base+ni;
+kern_base:=lig_kern_base+nlw;
+exten_base:=kern_base+nk;
+param_base:=exten_base+neew-1;
+end
+
+@ Of course we want to define macros that suppress the detail of how the
+font information is actually encoded. Each word will be referred to by
+the |tfm| index of its first byte. For example, if |c| is a character
+code between |bc| and |ec|, then |tfm[char_info(c)]| will be the
+first byte of its |char_info|, i.e., the |width_index|; furthermore
+|width(c)| will point to the |fix_word| for |c|'s width.
+
+@d char_info(#)==char_start[#]
+@d nonexistent(#)==((#<bc)or(#>ec)or(width_index(#)=0))
+@d width(#)==4*(width_base+width_index(#))
+@d height(#)==4*(height_base+height_index(#))
+@d depth(#)==4*(depth_base+depth_index(#))
+@d italic(#)==4*(italic_base+italic_index(#))
+@d kern(#)==4*(kern_base+#) {here \#\ is an index, not a character}
+@d param(#)==4*(param_base+#) {likewise}
+
+@p function width_index(c:char_type):integer;
+begin if not ofm_on then
+ width_index:=tfm[char_info(c)]
+else
+ width_index:=256*tfm[char_info(c)]+tfm[char_info(c)+1];
+end;
+
+function height_index(c:char_type):integer;
+begin if not ofm_on then
+ height_index:=tfm[char_info(c)+1] div 16
+else
+ height_index:=tfm[char_info(c)+2];
+end;
+
+function depth_index(c:char_type):integer;
+begin if not ofm_on then
+ depth_index:=tfm[char_info(c)+1] mod 16
+else
+ depth_index:=tfm[char_info(c)+3];
+end;
+
+function italic_index(c:char_type):integer;
+begin if not ofm_on then
+ italic_index:=tfm[char_info(c)+2] div 4
+else
+ italic_index:=tfm[char_info(c)+4];
+end;
+
+function tag(c:char_type):integer;
+begin if not ofm_on then
+ tag:=tfm[char_info(c)+2] mod 4
+else
+ tag:=tfm[char_info(c)+5] mod 4;
+end;
+
+procedure set_no_tag(c:char_type);
+begin if not ofm_on then
+ tfm[char_info(c)+2] := (tfm[char_info(c)+2] div 64)*64 + no_tag
+else
+ tfm[char_info(c)+5] := (tfm[char_info(c)+5] div 64)*64 + no_tag;
+end;
+
+procedure check_unused(c:char_type);
+var @!x:integer;
+begin if ofm_level=1 then x:=tfm[char_info(c)+5] div 8
+else x:=tfm[char_info(c)+5] div 4;
+if x<>0 then begin
+ if ofm_level=1 then x:=tfm[char_info(c)+5] mod 8
+ else x:=tfm[char_info(c)+5] mod 4;
+ tfm[char_info(c)+5]:=x;
+ perfect:=false; if chars_on_line>0 then print_ln(' ');
+ chars_on_line:=0; print_ln('Ignoring non-zero unused char info bits');
+@.Ignoring non-zero unused...@>
+ end;
+end;
+
+function ctag(c:char_type):boolean;
+begin if not (ofm_level=1) then
+ ctag:=false
+else
+ ctag:=tfm[char_info(c)+5] div 4 mod 2;
+end;
+
+procedure set_no_ctag(c:char_type);
+begin if not (ofm_level=1) then
+ tfm[char_info(c)+5] :=
+ tfm[char_info(c)+5] div 8 * 8 + tfm[char_info(c)+5] mod 4;
+end;
+
+function no_repeats(c:char_type):integer;
+begin if ofm_level<=0 then
+ no_repeats:=0
+else
+ no_repeats:=256*tfm[char_info(c)+8]+tfm[char_info(c)+9];
+end;
+
+function char_param(c:char_type; i:integer):integer;
+begin
+ char_param:=256*tfm[char_info(c)+2*i+10]+tfm[char_info(c)+2*i+11];
+end;
+
+function rremainder(c:char_type):integer;
+begin if not ofm_on then
+ rremainder:=tfm[char_info(c)+3]
+else
+ rremainder:=256*tfm[char_info(c)+6]+tfm[char_info(c)+7];
+end;
+
+function lig_step(c:char_type):integer;
+begin if not ofm_on then
+ lig_step:=4*(lig_kern_base+c)
+else
+ lig_step:=4*(lig_kern_base+2*c);
+end;
+
+function exten(c:char_type):integer;
+begin if not ofm_on then
+ exten:=4*(exten_base+rremainder(c))
+else
+ exten:=4*(exten_base+2*rremainder(c));
+end;
+
+function l_skip_byte(c:integer):integer;
+begin if not ofm_on then
+ l_skip_byte:=tfm[c]
+else
+ l_skip_byte:=256*tfm[c]+tfm[c+1];
+end;
+
+procedure set_l_skip_byte(c:integer; newc:integer);
+begin if not ofm_on then
+ tfm[c]:=newc
+else begin
+ tfm[c]:=newc div 256;
+ tfm[c+1]:=newc mod 256
+ end
+end;
+
+function l_next_char(c:integer):integer;
+begin if not ofm_on then
+ l_next_char:=tfm[c+1]
+else
+ l_next_char:=256*tfm[c+2]+tfm[c+3];
+end;
+
+procedure set_l_next_char(c:integer; newc:char_type);
+begin if not ofm_on then
+ tfm[c+1]:=newc
+else begin
+ tfm[c+2]:=newc div 256;
+ tfm[c+3]:=newc mod 256
+ end
+end;
+
+function l_op_byte(c:integer):integer;
+begin if not ofm_on then
+ l_op_byte:=tfm[c+2]
+else
+ l_op_byte:=256*tfm[c+4]+tfm[c+5];
+end;
+
+procedure set_l_op_byte(c:integer; newc:integer);
+begin if not ofm_on then
+ tfm[c+2]:=newc
+else begin
+ tfm[c+2]:=newc div 256;
+ tfm[c+3]:=newc mod 256
+ end
+end;
+
+function l_remainder(c:integer):integer;
+begin if not ofm_on then
+ l_remainder:=tfm[c+3]
+else
+ l_remainder:=256*tfm[c+6]+tfm[c+7];
+end;
+
+procedure set_l_remainder(c:integer; newc:char_type);
+begin if not ofm_on then
+ tfm[c+3]:=newc
+else begin
+ tfm[c+6]:=newc div 256;
+ tfm[c+7]:=newc mod 256
+ end
+end;
+
+@ One of the things we would like to do is take cognizance of fonts whose
+character coding scheme is \.{TeX math symbols} or \.{TeX math extension};
+we will set the |font_type| variable to one of the three choices
+|vanilla|, |mathsy|, or |mathex|.
+
+@d vanilla=0 {not a special scheme}
+@d mathsy=1 {\.{TeX math symbols} scheme}
+@d mathex=2 {\.{TeX math extension} scheme}
+
+@<Glob...@>=
+@!font_type:vanilla..mathex; {is this font special?}
+
+@* Basic output subroutines.
+Let us now define some procedures that will reduce the rest of \.{TFtoPL}'s
+work to a triviality.
+
+First of all, it is convenient to have an abbreviation for output to the
+\.{PL} file:
+
+@d out(#)==write(pl_file,#)
+
+@ In order to stick to standard \PASCAL, we use three strings called
+|ASCII_04|, |ASCII_10|, and |ASCII_14|, in terms of which we can do the
+appropriate conversion of ASCII codes. Three other little strings are
+used to produce |face| codes like \.{MIE}.
+
+@<Glob...@>=
+@!ASCII_04,@!ASCII_10,@!ASCII_14: packed array [1..32] of char;
+ {strings for output in the user's external character set}
+@!MBL_string,@!RI_string,@!RCE_string:packed array [1..3] of char;
+ {handy string constants for |face| codes}
+@!HEX: packed array [1..16] of char;
+
+@ @<Set init...@>=
+ASCII_04:=' !"#$%&''()*+,-./0123456789:;<=>?';@/
+ASCII_10:='@@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_';@/
+ASCII_14:='`abcdefghijklmnopqrstuvwxyz{|}~ ';@/
+MBL_string:='MBL'; RI_string:='RI '; RCE_string:='RCE';
+HEX:='0123456789ABCDEF';@/
+
+@ The array |dig| will hold a sequence of digits to be output.
+
+@<Glob...@>=
+@!dig:array[0..32] of integer;
+
+@ Here, in fact, are two procedures that output |dig[j-1]|$\,\ldots\,$|dig[0]|,
+given $j>0$.
+
+@p procedure out_digs(j:integer); {outputs |j| digits}
+begin repeat decr(j); out(HEX[1+dig[j]]);
+until j=0;
+end;
+@#
+procedure print_digs(j:integer); {prints |j| digits}
+begin repeat decr(j); print(HEX[1+dig[j]]);
+until j=0;
+end;
+
+@ The |print_number| procedure indicates how |print_digs| can be used.
+This procedure can print in octal, decimal or hex notation.
+
+@d print_hex(#)==print_number(#,16)
+@d print_octal(#)==print_number(#,8)
+@d print_decimal(#)==print_number(#,10)
+
+@p procedure print_number(c:integer; form:integer); {prints value of |c|}
+var j:0..32; {index into |dig|}
+begin
+j:=0;
+if (c<0) then begin
+ print_ln('Internal error: print_number (negative value)');
+ c:=0;
+ end;
+if form=8 then
+ print('''') {an apostrophe indicates the octal notation}
+else if form=16 then
+ print('"') { a double apostrophe indicates the hexadecimal notation}
+else if form<>10 then begin
+ print_ln('Internal error: print_number (form)');
+ form:=16;
+ end;
+while (c>0) or (j=0) do begin
+ dig[j]:=c mod form; c:=c div form;
+ j:=j+1;
+ end;
+print_digs(j);
+end;
+
+@ A \.{PL} file has nested parentheses, and we want to format the output
+so that its structure is clear. The |level| variable keeps track of the
+depth of nesting.
+
+@<Glob...@>=
+@!level:0..5;
+
+@ @<Set init...@>=
+level:=0;
+
+@ Three simple procedures suffice to produce the desired structure in the
+output.
+
+@p procedure out_ln; {finishes one line, indents the next}
+var l:0..5;
+begin write_ln(pl_file);
+for l:=1 to level do out(' ');
+end;
+@#
+procedure left; {outputs a left parenthesis}
+begin incr(level); out('(');
+end;
+@#
+procedure right; {outputs a right parenthesis and finishes a line}
+begin decr(level); out(')'); out_ln;
+end;
+
+@ The value associated with a property can be output in a variety of
+ways. For example, we might want to output a {\mc BCPL} string that
+begins in |tfm[k]|:
+
+@p procedure out_BCPL(@!k:index); {outputs a string, preceded by a blank space}
+var l:0..39; {the number of bytes remaining}
+begin out(' '); l:=tfm[k];
+while l>0 do
+ begin incr(k); decr(l);
+ case tfm[k] div @'40 of
+ 1: out(ASCII_04[1+(tfm[k] mod @'40)]);
+ 2: out(ASCII_10[1+(tfm[k] mod @'40)]);
+ 3: out(ASCII_14[1+(tfm[k] mod @'40)]);
+ end;
+ end;
+end;
+
+@ The property value might also be a sequence of |l| bytes, beginning
+in |tfm[k]|, that we would like to output in hex notation.
+The following procedure assumes that |l<=4|, but larger values of |l|
+could be handled easily by enlarging the |dig| array and increasing
+the upper bounds on |b| and |j|.
+
+@d out_octal_number(#)==out_number(#,8)
+@d out_decimal_number(#)==out_number(#,10)
+@d out_hex_number(#)==out_number(#,16)
+@d out_dec(#)==out_decimal_number(#)
+@d out_hex_char(#)==out_hex_number(#)
+
+@p procedure out_number(c:integer; form:integer); {outputs value of |c|}
+var j:0..32; {index into |dig|}
+begin
+j:=0;
+if (c<0) then begin
+ print_ln('Internal error: print_number (negative value)');
+ c:=0;
+ end;
+if form=8 then
+ out(' O ')
+else if form=10 then
+ out(' D ')
+else if form=16 then
+ out(' H ')
+else begin
+ print_ln('Internal error: print_number (form)');
+ form:=16;
+ out(' H ')
+ end;
+while (c>0) or (j=0) do begin
+ dig[j]:=c mod form; c:=c div form;
+ j:=j+1;
+ end;
+out_digs(j);
+end;
+@#
+procedure out_hex(@!k,@!l:index);
+ {outputs |l| bytes in hex}
+var a:0..@"7FFFFFFF; {accumulator for bits not yet output}
+@!b:0..32; {the number of significant bits in |a|}
+@!j:0..11; {the number of digits of output}
+begin
+out(' H ');
+a:=0; b:=0; j:=0;
+while l>0 do @<Reduce \(1)|l| by one, preserving the invariants@>;
+while (a>0)or(j=0) do begin
+ dig[j]:=a mod 16; a:=a div 16; incr(j);
+ end;
+out_digs(j);
+end;
+
+@ @<Reduce \(1)|l|...@>=
+begin decr(l);
+if tfm[k+l]<>0 then begin
+ while b>3 do begin
+ dig[j]:=a mod 16; a:=a div 16; b:=b-4; incr(j);
+ end;
+ case b of
+ 0: a:=tfm[k+l];
+ 1:a:=a+2*tfm[k+l];
+ 2:a:=a+4*tfm[k+l];
+ 3:a:=a+8*tfm[k+l];
+ end;
+ end;
+b:=b+8;
+end
+
+@ The property value may be a character, which is output in hex
+unless it is a letter or a digit. This procedure is the only place
+where a lowercase letter will be output to the \.{PL} file.
+@^system dependencies@>
+
+@p procedure out_char(@!c:integer); {outputs a character}
+begin if font_type>vanilla then
+ out_hex_char(c)
+else if (c>="0")and(c<="9") then
+ out(' C ',c-"0":1)
+else if (c>="A")and(c<="Z") then
+ out(' C ',ASCII_10[c-"A"+2])
+else if (c>="a")and(c<="z") then
+ out(' C ',ASCII_14[c-"a"+2])
+else out_hex_char(c);
+end;
+
+@ The property value might be a ``face'' byte, which is output in the
+curious code mentioned earlier, provided that it is less than 18.
+
+@p procedure out_face(@!k:index); {outputs a |face|}
+var s:0..1; {the slope}
+@!b:0..8; {the weight and expansion}
+begin if tfm[k]>=18 then out_hex(k,1)
+else begin out(' F '); {specify face-code format}
+ s:=tfm[k] mod 2; b:=tfm[k] div 2;
+ out(MBL_string[1+(b mod 3)]);
+ out(RI_string[1+s]);
+ out(RCE_string[1+(b div 3)]);
+ end;
+end;
+
+@ And finally, the value might be a |fix_word|, which is output in
+decimal notation with just enough decimal places for \.{PLtoTF}
+to recover every bit of the given |fix_word|.
+
+All of the numbers involved in the intermediate calculations of
+this procedure will be nonnegative and less than $10\cdot2^{24}$.
+
+@p procedure out_fix(@!k:index); {outputs a |fix_word|}
+var a:0..@'7777; {accumulator for the integer part}
+@!f:integer; {accumulator for the fraction part}
+@!j:0..12; {index into |dig|}
+@!delta:integer; {amount if allowable inaccuracy}
+begin out(' R '); {specify real format}
+a:=(tfm[k]*16)+(tfm[k+1] div 16);
+f:=((tfm[k+1] mod 16)*@'400+tfm[k+2])*@'400+tfm[k+3];
+if a>@'3777 then @<Reduce \(2)negative to positive@>;
+@<Output the integer part, |a|, in decimal notation@>;
+@<Output the fraction part, $|f|/2^{20}$, in decimal notation@>;
+end;
+
+@ The following code outputs at least one digit even if |a=0|.
+
+@<Output the integer...@>=
+begin j:=0;
+repeat dig[j]:=a mod 10; a:=a div 10; incr(j);
+until a=0;
+out_digs(j);
+end
+
+@ And the following code outputs at least one digit to the right
+of the decimal point.
+
+@<Output the fraction...@>=
+begin out('.'); f:=10*f+5; delta:=10;
+repeat if delta>@'4000000 then f:=f+@'2000000-(delta div 2);
+out(f div @'4000000:1); f:=10*(f mod @'4000000); delta:=delta*10;
+until f<=delta;
+end;
+
+@ @<Reduce \(2)negative to positive@>=
+begin out('-'); a:=@'10000-a;
+if f>0 then
+ begin f:=@'4000000-f; decr(a);
+ end;
+end
+
+@* Doing it.
+\TeX\ checks the information of a \.{TFM} file for validity as the
+file is being read in, so that no further checks will be needed when
+typesetting is going on. And when it finds something wrong, it justs
+calls the file ``bad,'' without identifying the nature of the problem,
+since \.{TFM} files are supposed to be good almost all of the time.
+
+Of course, a bad file shows up every now and again, and that's where
+\.{TFtoPL} comes in. This program wants to catch at least as many errors as
+\TeX\ does, and to give informative error messages besides.
+All of the errors are corrected, so that the \.{PL} output will
+be correct (unless, of course, the \.{TFM} file was so loused up
+that no attempt is being made to fathom it).
+
+@ Just before each character is processed, its code is printed in hex
+notation. Up to eight such codes appear on a line; so we have a variable
+to keep track of how many are currently there. We also keep track of
+whether or not any errors have had to be corrected.
+
+@<Glob...@>=
+@!chars_on_line:0..9; {the number of characters printed on the current line}
+@!perfect:boolean; {was the file free of errors?}
+
+@ @<Set init...@>=
+chars_on_line:=0;@/
+perfect:=true; {innocent until proved guilty}
+
+@ Error messages are given with the help of the |bad| and |range_error|
+and |bad_char| macros:
+
+@d bad(#)==begin perfect:=false; if chars_on_line>0 then print_ln(' ');
+ chars_on_line:=0; print_ln('Bad OFM file: ',#);
+ end
+@.Bad OFM file@>
+@d range_error(#)==begin perfect:=false; print_ln(' ');
+ print(#,' index for character ');
+ print_hex(c); print_ln(' is too large;');
+ print_ln('so I reset it to zero.');
+ end
+@d bad_char_tail(#)==print_hex(#); print_ln('.');
+ end
+@d bad_char(#)==begin perfect:=false; if chars_on_line>0 then print_ln(' ');
+ chars_on_line:=0; print('Bad OFM file: ',#,' nonexistent character ');
+ bad_char_tail
+@d correct_bad_char_tail(#)==#(k,0)
+ end
+@d correct_bad_char_middle(#)==print_hex(#(k)); print_ln('.');
+ correct_bad_char_tail
+@d correct_bad_char(#)== begin perfect:=false;
+ if chars_on_line>0 then print_ln(' ');
+ chars_on_line:=0; print('Bad OFM file: ',#,' nonexistent character ');
+ correct_bad_char_middle
+
+@<Glob...@>=
+@!i:integer; {an index to words of a subfile}
+@!c:xchar_type; {a random character}
+@!d:0..3; {byte number in a word}
+@!k:index; {a random index}
+@!r:0..max_char; {a random two-byte value}
+@!count:0..127; {for when we need to enumerate a small set}
+
+@ There are a lot of simple things to do, and they have to be done one
+at a time, so we might as well get down to business. The first things
+that \.{TFtoPL} will put into the \.{PL} file appear in the header part.
+
+@<Do the header@>=
+begin
+case ofm_level of
+0: begin out('(OFMLEVEL H 0)'); out_ln; end;
+1: begin out('(OFMLEVEL H 1)'); out_ln; end;
+end;
+if ofm_on then
+ begin left;
+ if font_dir<=7 then out('FONTDIR')
+ else out('NFONTDIR');
+ case font_dir mod 8 of
+ 0: out(' TL');
+ 1: out(' LT');
+ 2: out(' TR');
+ 3: out(' LB');
+ 4: out(' BL');
+ 5: out(' RT');
+ 6: out(' BR');
+ 7: out(' RB');
+ end;
+ right
+ end;
+font_type:=vanilla;
+if lh>=12 then begin
+ @<Set the true |font_type|@>;
+ if lh>=17 then begin
+ @<Output the family name@>;
+ if lh>=18 then @<Output the rest of the header@>;
+ end;
+ @<Output the character coding scheme@>;
+ end;
+@<Output the design size@>;
+@<Output the check sum@>;
+@<Output the |seven_bit_safe_flag|@>;
+end
+
+@ @<Output the check sum@>=
+left; out('CHECKSUM'); out_hex(check_sum,4);
+right
+
+@ Incorrect design sizes are changed to 10 points.
+
+@d bad_design(#)==begin bad('Design size ',#,'!');
+@.Design size wrong@>
+ print_ln('I''ve set it to 10 points.');
+ out(' D 10');
+ end
+
+@ @<Output the design size@>=
+left; out('DESIGNSIZE');
+if tfm[design_size]>127 then bad_design('negative')
+else if (tfm[design_size]=0)and(tfm[design_size+1]<16) then
+ bad_design('too small')
+else out_fix(design_size);
+right;
+out('(COMMENT DESIGNSIZE IS IN POINTS)'); out_ln;
+out('(COMMENT OTHER SIZES ARE MULTIPLES OF DESIGNSIZE)'); out_ln
+@.DESIGNSIZE IS IN POINTS@>
+
+@ Since we have to check two different {\mc BCPL} strings for validity,
+we might as well write a subroutine to make the check.
+
+@p procedure check_BCPL(@!k,@!l:index); {checks a string of length |<l|}
+var j:index; {runs through the string}
+@!c:integer; {character being checked}
+begin if tfm[k]>=l then
+ begin bad('String is too long; I''ve shortened it drastically.');
+@.String is too long...@>
+ tfm[k]:=1;
+ end;
+for j:=k+1 to k+tfm[k] do
+ begin c:=tfm[j];
+ if (c="(")or(c=")") then
+ begin bad('Parenthesis in string has been changed to slash.');
+@.Parenthesis...changed to slash@>
+ tfm[j]:="/";
+ end
+ else if (c<" ")or(c>"~") then
+ begin bad('Nonstandard ASCII code has been blotted out.');
+@.Nonstandard ASCII code...@>
+ tfm[j]:="?";
+ end
+ else if (c>="a")and(c<="z") then tfm[j]:=c+"A"-"a"; {upper-casify letters}
+ end;
+end;
+
+@ The |font_type| starts out |vanilla|; possibly we need to reset it.
+
+@<Set the true |font_type|@>=
+begin check_BCPL(scheme,40);
+if (tfm[scheme]>=11)and@|(tfm[scheme+1]="T")and@|
+ (tfm[scheme+2]="E")and@|(tfm[scheme+3]="X")and@|
+ (tfm[scheme+4]=" ")and@|(tfm[scheme+5]="M")and@|
+ (tfm[scheme+6]="A")and@|(tfm[scheme+7]="T")and@|
+ (tfm[scheme+8]="H")and@|(tfm[scheme+9]=" ") then
+ begin if (tfm[scheme+10]="S")and(tfm[scheme+11]="Y") then font_type:=mathsy
+ else if (tfm[scheme+10]="E")and(tfm[scheme+11]="X") then font_type:=mathex;
+ end;
+end
+
+@ @<Output the character coding scheme@>=
+left; out('CODINGSCHEME');
+out_BCPL(scheme);
+right
+
+@ @<Output the family name@>=
+left; out('FAMILY');
+check_BCPL(family,20);
+out_BCPL(family);
+right
+
+@ @<Output the rest of the header@>=
+begin left; out('FACE'); out_face(random_word+3); right;
+for i:=18 to lh-1 do
+ begin left; out('HEADER D ',i:1);
+ out_hex(check_sum+4*i,@,4); right;
+ end;
+end
+
+@ This program does not check to see if the |seven_bit_safe_flag| has the
+correct setting, i.e., if it really reflects the seven-bit-safety of
+the \.{TFM} file; the stated value is merely put into the \.{PL} file.
+The \.{PLtoTF} program will store a correct value and give a warning
+message if a file falsely claims to be safe.
+
+\.{OFM} files are assumed to be seven-bit-unsafe.
+
+@<Output the |seven_bit_safe_flag|@>=
+if ofm_on then
+ begin left; out('SEVENBITSAFEFLAG FALSE'); right;
+ end
+else if (lh>17) and (tfm[random_word]>127) then
+ begin left; out('SEVENBITSAFEFLAG TRUE'); right;
+ end
+
+@ The next thing to take care of is the list of parameters.
+
+@<Do the parameters@>=
+if np>0 then
+ begin left; out('FONTDIMEN'); out_ln;
+ for i:=1 to np do @<Check and output the $i$th parameter@>;
+ right;
+ end;
+@<Check to see if |np| is complete for this font type@>;
+
+@ @<Check to see if |np|...@>=
+if (font_type=mathsy)and(np<>22) then
+ print_ln('Unusual number of fontdimen parameters for a math symbols font (',
+@.Unusual number of fontdimen...@>
+ np:1,' not 22).')
+else if (font_type=mathex)and(np<>13) then
+ print_ln('Unusual number of fontdimen parameters for an extension font (',
+ np:1,' not 13).')
+
+@ All |fix_word| values except the design size and the first parameter
+will be checked to make sure that they are less than 16.0 in magnitude,
+using the |check_fix| macro:
+
+@d check_fix_tail(#)==bad(#,' ',i:1,' is too big;');
+ print_ln('I have set it to zero.');
+ end
+@d check_fix(#)==if (tfm[#]>0)and(tfm[#]<255) then
+ begin tfm[#]:=0; tfm[(#)+1]:=0; tfm[(#)+2]:=0; tfm[(#)+3]:=0;
+ check_fix_tail
+
+@<Check and output the $i$th parameter@>=
+begin left;
+if i=1 then out('SLANT') {this parameter is not checked}
+else begin check_fix(param(i))('Parameter');@/
+@.Parameter n is too big@>
+ @<Output the name of parameter $i$@>;
+ end;
+out_fix(param(i)); right;
+end
+
+@ @<Output the name...@>=
+if i<=7 then case i of
+ 2:out('SPACE');@+3:out('STRETCH');@+4:out('SHRINK');
+ 5:out('XHEIGHT');@+6:out('QUAD');@+7:out('EXTRASPACE')@+end
+else if (i<=22)and(font_type=mathsy) then case i of
+ 8:out('NUM1');@+9:out('NUM2');@+10:out('NUM3');
+ 11:out('DENOM1');@+12:out('DENOM2');
+ 13:out('SUP1');@+14:out('SUP2');@+15:out('SUP3');
+ 16:out('SUB1');@+17:out('SUB2');
+ 18:out('SUPDROP');@+19:out('SUBDROP');
+ 20:out('DELIM1');@+21:out('DELIM2');
+ 22:out('AXISHEIGHT')@+end
+else if (i<=13)and(font_type=mathex) then
+ if i=8 then out('DEFAULTRULETHICKNESS')
+ else out('BIGOPSPACING',i-8:1)
+else out('PARAMETER D ',i:1)
+
+@ @<Glob...@>=
+@!start_counter,@!base_counter,@!number_entries:integer;
+@!value:integer;
+
+@ @<Do the ivalue parameters@>=
+if nki>0 then begin
+ start_counter:=ivalues_start*4;
+ base_counter:=ivalues_base*4;
+ for i:=0 to nki-1 do @<Check and output the $i$th ivalue table@>;
+ end;
+
+@ @<Check and output the $i$th ivalue table@>=
+begin
+left; out('FONTIVALUE'); out_hex_number(i); out_ln;
+number_entries:=256*tfm[start_counter+2]+tfm[start_counter+3];
+for j:=0 to number_entries-1 do begin
+ left; out('IVALUE'); out_hex_number(j); out_ln;
+ value:=256*tfm[base_counter+2]+tfm[base_counter+3];
+ left; out('IVALUEVAL'); out_hex_number(value); right;
+ right;
+ base_counter:=base_counter+4;
+ end;
+right;
+start_counter:=start_counter+4;
+end;
+
+@ @<Do the fvalue parameters@>=
+if nkf>0 then begin
+ start_counter:=fvalues_start*4;
+ base_counter:=fvalues_base*4;
+ for i:=0 to nkf-1 do @<Check and output the $i$th fvalue table@>;
+ end;
+
+@ @<Check and output the $i$th fvalue table@>=
+begin
+left; out('FONTFVALUE'); out_hex_number(i); out_ln;
+number_entries:=256*tfm[start_counter+2]+tfm[start_counter+3];
+for j:=0 to number_entries-1 do begin
+ left; out('FVALUE'); out_hex_number(j); out_ln;
+ left; out('FVALUEVAL'); out_fix(base_counter); right;
+ right;
+ base_counter:=base_counter+4;
+ end;
+right;
+start_counter:=start_counter+4;
+end;
+
+@ @<Do the mvalue parameters@>=
+if nkm>0 then begin
+ start_counter:=mvalues_start*4;
+ base_counter:=mvalues_base*4;
+ for i:=0 to nkm-1 do @<Check and output the $i$th mvalue table@>;
+ end;
+
+@ @<Check and output the $i$th mvalue table@>=
+begin
+left; out('FONTMVALUE'); out_hex_number(i); out_ln;
+number_entries:=256*tfm[start_counter+2]+tfm[start_counter+3];
+for j:=0 to number_entries-1 do begin
+ left; out('MVALUE'); out_hex_number(j); out_ln;
+ left; out('MVALUEVAL'); out_fix(base_counter); right;
+ right;
+ base_counter:=base_counter+4;
+ end;
+right;
+start_counter:=start_counter+4;
+end;
+
+@ @<Do the rule parameters@>=
+if nkr>0 then
+ begin start_counter:=rules_start*4;
+ base_counter:=rules_base*4;
+ for i:=0 to nkr-1 do @<Check and output the $i$th rule table@>;
+ end
+
+@ @<Check and output the $i$th rule table@>=
+begin left; out('FONTRULE'); out_hex_number(i); out_ln;
+number_entries:=256*tfm[start_counter+2]+tfm[start_counter+3];
+for j:=0 to number_entries-1 do
+ begin left; out('RULE'); out_hex_number(j); out_ln;
+ left; out('RULEWD'); out_fix(base_counter); right;
+ left; out('RULEHT'); out_fix(base_counter+4); right;
+ left; out('RULEDP'); out_fix(base_counter+8); right;
+ right;
+ base_counter:=base_counter+12;
+ end;
+right;
+start_counter:=start_counter+4;
+end;
+
+@ @<Do the glue parameters@>=
+if nkg>0 then
+ begin start_counter:=glues_start*4;
+ base_counter:=glues_base*4;
+ for i:=0 to nkg-1 do @<Check and output the $i$th glue table@>;
+ end;
+
+@ @<Glob...@>=
+@!glue_subtype,@!glue_argument_kind,@!glue_stretch_order,
+@!glue_shrink_order,@!glue_argument:integer;
+
+@ @<Check and output the $i$th glue table@>=
+begin left; out('FONTGLUE'); out_hex_number(i); out_ln;
+number_entries:=256*tfm[start_counter+2]+tfm[start_counter+3];
+for j:=0 to number_entries-1 do
+ begin left; out('GLUE'); out_hex_number(j); out_ln;
+ glue_subtype:=tfm[base_counter] div 16;
+ glue_argument_kind:=tfm[base_counter] mod 16;
+ glue_stretch_order:=tfm[base_counter+1] div 16;
+ glue_shrink_order:=tfm[base_counter+1] mod 16;
+ glue_argument:=tfm[base_counter+2]*256+tfm[base_counter+3];
+ left;
+ out('GLUETYPE');
+ case glue_subtype of
+ 0: out(' H 0');
+ 1: out(' H 1');
+ 2: out(' H 2');
+ 3: out(' H 3');
+ end;
+ right;
+ case glue_argument_kind of
+ 1: begin
+ left; out('GLUERULE'); out_hex_number(glue_argument); right;
+ end;
+ 2: begin
+ left; out('GLUECHAR'); out_hex_number(glue_argument); right;
+ end;
+ end;
+ left;
+ out('GLUESTRETCHORDER');
+ case glue_stretch_order of
+ 0: out(' H 0');
+ 1: out(' H 1');
+ 2: out(' H 2');
+ 3: out(' H 3');
+ 4: out(' H 4');
+ end;
+ right;
+ left;
+ out('GLUESHRINKORDER');
+ case glue_shrink_order of
+ 0: out(' H 0');
+ 1: out(' H 1');
+ 2: out(' H 2');
+ 3: out(' H 3');
+ 4: out(' H 4');
+ end;
+ right;
+ left; out('GLUEWD'); out_fix(base_counter+4); right;
+ left; out('GLUESTRETCH'); out_fix(base_counter+8); right;
+ left; out('GLUESHRINK'); out_fix(base_counter+12); right;
+ right;
+ base_counter:=base_counter+16;
+ end;
+right;
+start_counter:=start_counter+4;
+end;
+
+@ @<Do the penalty parameters@>=
+if nkp>0 then
+ begin start_counter:=penalties_start*4;
+ base_counter:=penalties_base*4;
+ for i:=0 to nkp-1 do @<Check and output the $i$th penalty table@>;
+ end;
+
+@ @<Check and output the $i$th penalty table@>=
+begin
+left; out('FONTPENALTY'); out_hex_number(i); out_ln;
+number_entries:=256*tfm[start_counter+2]+tfm[start_counter+3];
+for j:=0 to number_entries-1 do begin
+ left; out('PENALTY'); out_hex_number(j); out_ln;
+ value:=256*tfm[base_counter+2]+tfm[base_counter+3];
+ left; out('PENALTYVAL'); out_hex_number(value); right;
+ right;
+ base_counter:=base_counter+4;
+ end;
+right;
+start_counter:=start_counter+4;
+end;
+
+@ We need to check the range of all the remaining |fix_word| values,
+and to make sure that |width[0]=0|, etc.
+
+@d nonzero_fix(#)==(tfm[#]>0)or(tfm[#+1]>0)or(tfm[#+2]>0)or(tfm[#+3]>0)
+
+@<Check the |fix_word| entries@>=
+if nonzero_fix(4*width_base) then bad('width[0] should be zero.');
+@.should be zero@>
+if nonzero_fix(4*height_base) then bad('height[0] should be zero.');
+if nonzero_fix(4*depth_base) then bad('depth[0] should be zero.');
+if nonzero_fix(4*italic_base) then bad('italic[0] should be zero.');
+for i:=0 to nw-1 do check_fix(4*(width_base+i))('Width');
+@.Width n is too big@>
+for i:=0 to nh-1 do check_fix(4*(height_base+i))('Height');
+@.Height n is too big@>
+for i:=0 to nd-1 do check_fix(4*(depth_base+i))('Depth');
+@.Depth n is too big@>
+for i:=0 to ni-1 do check_fix(4*(italic_base+i))('Italic correction');
+@.Italic correction n is too big@>
+if nk>0 then for i:=0 to nk-1 do check_fix(kern(i))('Kern');
+@.Kern n is too big@>
+
+@ The ligature/kerning program comes next. Before we can put it out in
+\.{PL} format, we need to make a table of ``labels'' that will be inserted
+into the program. For each character |c| whose |tag| is |lig_tag| and
+whose starting address is |r|, we will store the pair |(c,r)| in the
+|label_table| array. If there's a boundary-char program starting at~|r|,
+we also store the pair |(256,r)|.
+This array is sorted by its second components, using the
+simple method of straight insertion.
+
+@<Glob...@>=
+@!label_table:array[xxxchar_type] of record
+@!cc:xchar_type;@!rr:0..lig_size;ischar:boolean;end;
+@!label_ptr:xxchar_type; {the largest entry in |label_table|}
+@!sort_ptr:xxchar_type; {index into |label_table|}
+@!boundary_char:xchar_type; {boundary character, or |xmax_char| if none}
+@!bchar_label:0..xmax_label; {beginning of boundary character program}
+
+@ @<Set init...@>=
+boundary_char:=xmax_char; bchar_label:=xmax_label;@/
+label_ptr:=0; label_table[0].rr:=0; {a sentinel appears at the bottom}
+
+@ We'll also identify and remove inaccessible program steps, using the
+|activity| array.
+
+@d unreachable=0 {a program step not known to be reachable}
+@d pass_through=1 {a program step passed through on initialization}
+@d accessible=2 {a program step that can be relevant}
+
+@<Glob...@>=
+@!activity:array[0..lig_size] of unreachable..accessible;
+@!ai,@!acti:0..lig_size; {indices into |activity|}
+
+@ @<Do the ligatures and kerns@>=
+if nl>0 then
+ begin for ai:=0 to nl-1 do activity[ai]:=unreachable;
+ @<Check for a boundary char@>;
+ end;
+@<Build the label table@>;
+if nl>0 then
+ begin left; out('LIGTABLE'); out_ln;@/
+ @<Compute the |activity| array@>;
+ @<Output and correct the ligature/kern program@>;
+ right;
+ @<Check for ligature cycles@>;
+ end
+
+@ We build the label table even when |nl=0|, because this catches errors
+that would not otherwise be detected.
+
+@<Build...@>=
+for c:=bc to ec do
+if (tag(c)=lig_tag) or (ctag(c)) then
+ begin r:=rremainder(c);
+ if (l_skip_byte(lig_step(r)) div 256)=0 then begin
+ if r<nl then begin
+ if l_skip_byte(lig_step(r))>stop_flag then begin
+ r:=256*l_op_byte(lig_step(r))+l_remainder(lig_step(r));
+ if r<nl then
+ if activity[rremainder(c)]=unreachable then
+ activity[rremainder(c)]:=pass_through;
+ end;
+ end;
+ end;
+ if r>=nl then
+ begin perfect:=false; print_ln(' ');
+ print('Ligature/kern starting index for character '); print_hex(c);
+ print_ln(' is too large;'); print_ln('so I removed it.'); set_no_tag(c);
+ set_no_ctag(c);
+@.Ligature/kern starting index...@>
+ end
+ else @<Insert |(c,r)| into |label_table|@>;
+ end;
+label_table[label_ptr+1].rr:=lig_size; {put ``infinite'' sentinel at the end}
+
+@ @<Insert |(c,r)|...@>=
+begin sort_ptr:=label_ptr; {there's a hole at position |sort_ptr+1|}
+while label_table[sort_ptr].rr>r do
+ begin label_table[sort_ptr+1]:=label_table[sort_ptr];
+ decr(sort_ptr); {move the hole}
+ end;
+label_table[sort_ptr+1].ischar:=not ctag(c);
+if ctag(c) then
+ label_table[sort_ptr+1].cc:=char_param(c,0)
+else
+ label_table[sort_ptr+1].cc:=c;
+label_table[sort_ptr+1].rr:=r; {fill the hole}
+incr(label_ptr); activity[r]:=accessible;
+end
+
+@ @<Check for a bound...@>=
+if l_skip_byte(lig_step(0))=255 then
+ begin left; out('BOUNDARYCHAR');
+ boundary_char:=l_next_char(lig_step(0)); out_char(boundary_char); right;
+ activity[0]:=pass_through;
+ end;
+if l_skip_byte(lig_step(nl-1))=255 then
+ begin r:=256*l_op_byte(lig_step(nl-1))+l_remainder(lig_step(nl-1));
+ if r>=nl then
+ begin perfect:=false; print_ln(' ');
+ print('Ligature/kern starting index for boundarychar is too large;');
+ print_ln('so I removed it.');
+@.Ligature/kern starting index...@>
+ end
+ else begin label_ptr:=1; label_table[1].cc:=xmax_char; label_table[1].rr:=r;
+ bchar_label:=r; activity[r]:=accessible;
+ end;
+ activity[nl-1]:=pass_through;
+ end
+
+@ @<Compute the |activity| array@>=
+for ai:=0 to (nl-1) do
+if (l_skip_byte(lig_step(ai)) div 256)=1 then
+ activity[ai]:=accessible
+else if activity[ai]=accessible then begin
+ r:=l_skip_byte(lig_step(ai));
+ if r<stop_flag then begin
+ r:=r+ai+1;
+ if r>=nl then begin
+ bad('Ligature/kern step ',ai:1,' skips too far;');
+@.Lig...skips too far@>
+ print_ln('I made it stop.'); set_l_skip_byte(lig_step(ai),stop_flag);
+ end
+ else activity[r]:=accessible;
+ end;
+ end
+
+@ We ignore |pass_through| items, which don't need to be mentioned in
+the \.{PL} file.
+
+@<Output and correct the ligature...@>=
+sort_ptr:=1; {point to the next label that will be needed}
+for acti:=0 to nl-1 do if activity[acti]<>pass_through then
+ begin i:=acti; @<Take care of commenting out unreachable steps@>;
+ @<Output any labels for step $i$@>;
+ @<Output step $i$ of the ligature/kern program@>;
+ end;
+if level=2 then right {the final step was unreachable}
+
+@ @<Globals...@>=
+@!output_clabels:array[0..256] of boolean;
+@!clabel_runner:integer;
+
+@ @<Set init...@>=
+for clabel_runner:=0 to 256 do
+ output_clabels[clabel_runner]:=false;
+
+@ @<Output any labels...@>=
+while i=label_table[sort_ptr].rr do begin
+ if label_table[sort_ptr].cc<>xmax_char and not label_table[sort_ptr].ischar then begin
+ if not output_clabels[label_table[sort_ptr].cc] then begin
+ output_clabels[label_table[sort_ptr].cc]:=true;
+ left;
+ out('CLABEL');
+ out_char(label_table[sort_ptr].cc);
+ right;
+ end
+ end
+ else begin
+ left;
+ out('LABEL');
+ if label_table[sort_ptr].cc=xmax_char then out(' BOUNDARYCHAR')
+ else out_char(label_table[sort_ptr].cc);
+ right;
+ end;
+ incr(sort_ptr);
+ end
+
+@ @<Take care of commenting out...@>=
+if activity[i]=unreachable then
+ begin if level=1 then
+ begin left; out('COMMENT THIS PART OF THE PROGRAM IS NEVER USED!'); out_ln;
+ end
+ end
+else if level=2 then right
+
+@ @<Output step $i$...@>=
+begin k:=lig_step(i);
+if (l_skip_byte(k) div 256)=1 then begin
+ case l_op_byte(k) of
+ 17: begin
+ left; out('CPEN');
+ out_hex_number(l_next_char(k));
+ out_hex_number(l_remainder(k));
+ right;
+ end;
+ 18: begin
+ left; out('CGLUE');
+ out_hex_number(l_next_char(k));
+ out_hex_number(l_remainder(k));
+ right;
+ end;
+ 19: begin
+ left; out('CPENGLUE');
+ out_hex_number(l_next_char(k));
+ out_hex_number(l_remainder(k) div 256);
+ out_hex_number(l_remainder(k) mod 256);
+ right;
+ end;
+ 20: begin
+ left; out('CKRN');
+ out_hex_number(l_next_char(k));
+ r:=l_remainder(k);
+ if r>=nk then begin
+ bad('Kern index too large.');
+@.Kern index too large@>
+ out(' R 0.0');
+ end
+ else out_fix(kern(r));
+ right;
+ end;
+ end;
+ end
+else if l_skip_byte(k)>stop_flag then begin
+ if (256*l_op_byte(k)+l_remainder(k))>=nl then
+ bad('Ligature unconditional stop command address is too big.');
+@.Ligature unconditional stop...@>
+ end
+else if l_op_byte(k)>=kern_flag then @<Output a kern step@>
+else @<Output a ligature step@>;
+if (l_skip_byte(k) mod 256)>0 then
+ if level=1 then @<Output either \.{SKIP} or \.{STOP}@>;
+end
+
+@ The \.{SKIP} command is a bit tricky, because we will be omitting all
+inaccessible commands.
+
+@<Output either...@>=
+begin if (l_skip_byte(k) mod 256)>=stop_flag then out('(STOP)')
+else begin count:=0;
+ for ai:=i+1 to (i+(l_skip_byte(k) mod 256)) do
+ if activity[ai]=accessible then incr(count);
+ out('(SKIP D ',count:1,')'); {possibly $count=0$, so who cares}
+ end;
+out_ln;
+end
+
+@ @<Output a kern step@>=
+begin if nonexistent(l_next_char(k)) then
+ if l_next_char(k)<>boundary_char then
+ correct_bad_char('Kern step for')(l_next_char)(set_l_next_char);
+@.Kern step for nonexistent...@>
+left; out('KRN'); out_char(l_next_char(k));
+r:=256*(l_op_byte(k)-kern_flag)+l_remainder(k);
+if r>=nk then
+ begin bad('Kern index too large.');
+@.Kern index too large@>
+ out(' R 0.0');
+ end
+else out_fix(kern(r));
+right;
+end
+
+@ @<Output a ligature step@>=
+begin if nonexistent(l_next_char(k)) then
+ if l_next_char(k)<>boundary_char then
+ correct_bad_char('Ligature step for')(l_next_char)(set_l_next_char);
+@.Ligature step for nonexistent...@>
+if nonexistent(l_remainder(k)) then
+ correct_bad_char('Ligature step produces the')(l_remainder)(set_l_remainder);
+@.Ligature step produces...@>
+left; r:=l_op_byte(k);
+if (r=4)or((r>7)and(r<>11)) then
+ begin print_ln('Ligature step with nonstandard code changed to LIG');
+ r:=0; set_l_op_byte(k,0);
+ end;
+if r mod 4>1 then out('/');
+out('LIG');
+if odd(r) then out('/');
+while r>3 do
+ begin out('>'); r:=r-4;
+ end;
+out_char(l_next_char(k)); out_char(l_remainder(k)); right;
+end
+
+@ The last thing on \.{TFtoPL}'s agenda is to go through the
+list of |char_info| and spew out the information about each individual
+character.
+
+@<Do the characters@>=
+sort_ptr:=0; {this will suppress `\.{STOP}' lines in ligature comments}
+c:=bc;
+while (c<=ec) do
+ begin if width_index(c)>0 then
+ begin if chars_on_line>=8 then
+ begin print_ln(' '); chars_on_line:=1;
+ end
+ else begin if chars_on_line>0 then print(' ');
+ incr(chars_on_line);
+ end;
+ if no_repeats(c)>0 then begin
+ print_hex(c); print('-'); print_hex(c+no_repeats(c)); incr(chars_on_line);
+ left; out('CHARREPEAT'); out_char(c); out_char(no_repeats(c)); out_ln;
+ end
+ else begin
+ print_hex(c); {progress report}
+ left; out('CHARACTER'); out_char(c); out_ln;
+ end;
+ if ofm_on then check_unused(c);
+ @<Output the character's width@>;
+ if height_index(c)>0 then @<Output the character's height@>;
+ if depth_index(c)>0 then @<Output the character's depth@>;
+ if italic_index(c)>0 then @<Output the italic correction@>;
+ case tag(c) of
+ no_tag: do_nothing;
+ lig_tag: @<Output the applicable part of the ligature/kern
+ program as a comment@>;
+ list_tag: @<Output the character link unless there is a problem@>;
+ ext_tag: @<Output an extensible character recipe@>;
+ end; {there are no other cases}
+ for i:=0 to npc-1 do begin
+ if char_param(c,i)<>0 then begin
+ left;
+ if i<nki then begin
+ out('CHARIVALUE'); out_hex_number(i);
+ end
+ else if i<(nki+nkf) then begin
+ out('CHARFVALUE'); out_hex_number(i-nki);
+ end
+ else if i<(nki+nkf+nkm) then begin
+ out('CHARMVALUE'); out_hex_number(i-nki-nkf);
+ end
+ else if i<(nki+nkf+nkm+nkr) then begin
+ out('CHARRULE'); out_hex_number(i-nki-nkf-nkm);
+ end
+ else if i<(nki+nkf+nkm+nkr+nkg) then begin
+ out('CHARGLUE'); out_hex_number(i-nki-nkf-nkm-nkr);
+ end
+ else if i<(nki+nkf+nkm+nkr+nkg+nkp) then begin
+ out('CHARPENALTY'); out_hex_number(i-nki-nkf-nkm-nkr-nkg);
+ end;
+ out_hex_number(char_param(c,i));
+ right;
+ end;
+ end;
+ right;
+ end;
+ c:=c+1+no_repeats(c);
+ end
+
+@ @<Output the character's width@>=
+if width_index(c)>=nw then range_error('Width')
+@.Width index for char...@>
+else begin left; out('CHARWD'); out_fix(width(c)); right;
+ end
+
+@ @<Output the character's height@>=
+if height_index(c)>=nh then range_error('Height')
+@.Height index for char...@>
+else begin left; out('CHARHT'); out_fix(height(c)); right;
+ end
+
+@ @<Output the character's depth@>=
+if depth_index(c)>=nd then range_error('Depth')
+@.Depth index for char@>
+else begin left; out('CHARDP'); out_fix(depth(c)); right;
+ end
+
+@ @<Output the italic correction@>=
+if italic_index(c)>=ni then range_error('Italic correction')
+@.Italic correction index for char...@>
+else begin left; out('CHARIC'); out_fix(italic(c)); right;
+ end
+
+@ @<Output the applicable part of the ligature...@>=
+begin left; out('COMMENT'); out_ln;@/
+i:=rremainder(c); r:=lig_step(i);
+if (l_skip_byte(r) mod 256)>stop_flag then i:=256*l_op_byte(r)+l_remainder(r);
+repeat @<Output step...@>;
+if (l_skip_byte(k) mod 256)>=stop_flag then i:=nl
+else i:=i+1+(l_skip_byte(k) mod 256);
+until i>=nl;
+right;
+end
+
+@ We want to make sure that there is no cycle of characters linked together
+by |list_tag| entries, since \TeX\ doesn't want to risk endless loops.
+If such a cycle exists, the routine here detects it when processing
+the largest character code in the cycle.
+
+@<Output the character link unless there is a problem@>=
+begin r:=rremainder(c);
+if nonexistent(r) then
+ begin bad_char('Character list link to')(r); set_no_tag(c);
+@.Character list link...@>
+ end
+else begin while (r<c)and(tag(r)=list_tag) do r:=rremainder(r);
+ if r=c then
+ begin bad('Cycle in a character list!');
+@.Cycle in a character list@>
+ print('Character '); print_hex(c);
+ print_ln(' now ends the list.');
+ set_no_tag(c);
+ end
+ else begin left; out('NEXTLARGER'); out_char(rremainder(c));
+ right;
+ end;
+ end;
+end
+
+@ @<Output an extensible character recipe@>=
+if rremainder(c)>=ne then
+ begin range_error('Extensible'); set_no_tag(c);
+@.Extensible index for char@>
+ end
+else begin left; out('VARCHAR'); out_ln;
+ @<Output the extensible pieces that exist@>;
+ right;
+ end
+
+@ @<Glob...@>=
+@!exten_char:integer;
+
+@ @<Output the extensible pieces that...@>=
+for d:=0 to 3 do begin
+ if not ofm_on then begin
+ k:=exten(c)+d;
+ exten_char:=tfm[k];
+ end
+ else begin
+ k:=exten(c)+2*d;
+ exten_char:=256*tfm[k]+tfm[k+1];
+ end;
+ if (d=3)or(exten_char>0) then begin
+ left;
+ case d of
+ 0:out('TOP');@+1:out('MID');@+2:out('BOT');@+3:out('REP')@+end;
+ if nonexistent(exten_char) then out_char(c)
+ else out_char(exten_char);
+ right;
+ end
+ end
+
+@ Some of the extensible recipes may not actually be used, but \TeX\ will
+complain about them anyway if they refer to nonexistent characters.
+Therefore \.{TFtoPL} must check them too.
+
+@<Check the extensible recipes@>=
+if ne>0 then
+ for c:=0 to ne-1 do
+ for d:=0 to 3 do begin
+ if not ofm_on then begin
+ k:=4*(exten_base+c)+d;
+ exten_char:=tfm[k];
+ end
+ else begin
+ k:=4*(exten_base+c)+2*d;
+ exten_char:=256*tfm[k]+tfm[k+1];
+ end;
+ if (exten_char>0)or(d=3) then begin
+ if nonexistent(exten_char) then begin
+ bad_char('Extensible recipe involves the')(exten_char);
+@.Extensible recipe involves...@>
+ if d<3 then begin
+ if not ofm_on then begin
+ tfm[k]:=0;
+ end
+ else begin
+ tfm[k]:=0;
+ tfm[k+1]:=0;
+ end;
+ end;
+ end;
+ end;
+ end
+
+@* Checking for ligature loops.
+We have programmed almost everything but the most interesting calculation of
+all, which has been saved for last as a special treat. \TeX's extended ligature
+mechanism allows unwary users to specify sequences of ligature replacements
+that never terminate. For example, the pair of commands
+$$\.{(/LIG $x$ $y$) (/LIG $y$ $x$)}$$
+alternately replaces character $x$ by character $y$ and vice versa. A similar
+loop occurs if \.{(LIG/ $z$ $y$)} occurs in the program for $x$ and
+ \.{(LIG/ $z$ $x$)} occurs in the program for $y$.
+
+More complicated loops are also possible. For example, suppose the ligature
+programs for $x$ and $y$ are
+$$\vcenter{\halign{#\hfil\cr
+\.{(LABEL $x$)(/LIG/ $z$ $w$)(/LIG/> $w$ $y$)} \dots,\cr
+\.{(LABEL $y$)(LIG $w$ $x$)} \dots;\cr}}$$
+then the adjacent characters $xz$ change to $xwz$, $xywz$, $xxz$, $xxwz$,
+\dots, ad infinitum.
+
+@ To detect such loops, \.{TFtoPL} attempts to evaluate the function
+$f(x,y)$ for all character pairs $x$ and~$y$, where $f$ is defined as
+follows: If the current character is $x$ and the next character is
+$y$, we say the ``cursor'' is between $x$ and $y$; when the cursor
+first moves past $y$, the character immediately to its left is
+$f(x,y)$. This function is defined if and only if no infinite loop is
+generated when the cursor is between $x$ and~$y$.
+
+The function $f(x,y)$ can be defined recursively. It turns out that all pairs
+$(x,y)$ belong to one of five classes. The simplest class has $f(x,y)=y$; this
+happens if there's no ligature between $x$ and $y$, or in the cases
+\.{LIG/>} and \.{/LIG/>>}. Another simple class arises when there's a
+\.{LIG} or \.{/LIG>} between $x$ and~$y$, generating the character~$z$;
+then $f(x,y)=z$. Otherwise we always have $f(x,y)$ equal to
+either $f(x,z)$ or $f(z,y)$ or $f(f(x,z),y)$, where $z$ is the inserted
+ligature character.
+
+The first two of these classes can be merged; we can also consider
+$(x,y)$ to belong to the simple class when $f(x,y)$ has been evaluated.
+For technical reasons we allow $x$ to be 256 (for the boundary character
+at the left) or 257 (in cases when an error has been detected).
+
+For each pair $(x,y)$ having a ligature program step, we store
+$(x,y)$ in a hash table from which the values $z$ and $class$ can be read.
+
+@d simple=0 {$f(x,y)=z$}
+@d left_z=1 {$f(x,y)=f(z,y)$}
+@d right_z=2 {$f(x,y)=f(x,z)$}
+@d both_z=3 {$f(x,y)=f(f(x,z),y)$}
+@d pending=4 {$f(x,y)$ is being evaluated}
+
+@<Glob...@>=
+@!hash:array[0..hash_size] of integer64;
+@!class:array[0..hash_size] of simple..pending;
+@!lig_z:array[0..hash_size] of xxchar_type;
+@!hash_ptr:0..hash_size; {the number of nonzero entries in |hash|}
+@!hash_list:array[0..hash_size] of 0..hash_size; {list of those nonzero entries}
+@!h,@!hh:0..hash_size; {indices into the hash table}
+@!x_lig_cycle,@!y_lig_cycle:integer; {problematic ligature pair}
+
+@ @<Check for ligature cycles@>=
+hash_ptr:=0; y_lig_cycle:=xmax_char;
+for hh:=0 to hash_size do hash[hh]:=0; {clear the hash table}
+for c:=bc to ec do if tag(c)=lig_tag then
+ begin i:=rremainder(c);
+ if (l_skip_byte(lig_step(i)) mod 256)>stop_flag then
+ i:=256*l_op_byte(lig_step(i))+l_remainder(lig_step(i));
+ @<Enter data for character $c$ starting at location |i| in the hash table@>;
+ end;
+if bchar_label<nl then
+ begin c:=xmax_char; i:=bchar_label;
+ @<Enter data for character $c$ starting at location |i| in the hash table@>;
+ end;
+if hash_ptr=hash_size then
+ begin print_ln('Sorry, I haven''t room for so many ligature/kern pairs!');
+@.Sorry, I haven't room...@>
+ goto final_end;
+ end;
+for hh:=1 to hash_ptr do
+ begin r:=hash_list[hh];
+ if class[r]>simple then {make sure $f$ is defined}
+ r:=f(r,(hash[r]-1)div xmax_char,(hash[r]-1)mod xmax_char);
+ end;
+if y_lig_cycle<xmax_char then
+ begin print('Infinite ligature loop starting with ');
+@.Infinite ligature loop...@>
+ if x_lig_cycle=xmax_char then print('boundary')@+else print_hex(x_lig_cycle);
+ print(' and '); print_hex(y_lig_cycle); print_ln('!');
+ out('(INFINITE LIGATURE LOOP MUST BE BROKEN!)'); out_ln; perfect:=false;
+ end
+
+@ @<Enter data for character $c$...@>=
+repeat hash_input; k:=l_skip_byte(lig_step(i));
+if k>=stop_flag then i:=nl
+else i:=i+1+k;
+until i>=nl
+
+@ We use an ``ordered hash table'' with linear probing, because such a table
+is efficient when the lookup of a random key tends to be unsuccessful.
+
+@p procedure hash_input; {enter data for character |c| and command |i|}
+label 30; {go here for a quick exit}
+var @!cc:simple..both_z; {class of data being entered}
+@!zz:char_type; {function value or ligature character being entered}
+@!y:char_type; {the character after the cursor}
+@!key:integer64; {value to be stored in |hash|}
+@!t64:integer64; {temporary register for swapping}
+@!t:integer; {temporary register for swapping}
+begin if hash_ptr=hash_size then goto 30;
+@<Compute the command parameters |y|, |cc|, and |zz|@>;
+key:=int64cast(xmax_char)*c+y+1; h:=(hash_mult*key) mod hash_size;
+while hash[h]>0 do
+ begin if hash[h]<=key then
+ begin if hash[h]=key then goto 30; {unused ligature command}
+ t64:=hash[h]; hash[h]:=key; key:=t64; {do ordered-hash-table insertion}
+ t:=class[h]; class[h]:=cc; cc:=t; {namely, do a swap}
+ t:=lig_z[h]; lig_z[h]:=zz; zz:=t;
+ end;
+ if h>0 then decr(h)@+else h:=hash_size;
+ end;
+hash[h]:=key; class[h]:=cc; lig_z[h]:=zz;
+incr(hash_ptr); hash_list[hash_ptr]:=h;
+30:end;
+
+@ We must store kern commands as well as ligature commands, because the former
+might make the latter inapplicable.
+
+@<Compute the command param...@>=
+k:=lig_step(i); y:=l_next_char(k); t:=l_op_byte(k);
+cc:=simple; zz:=l_remainder(k);
+if t>=kern_flag then zz:=y
+else begin case t of
+ 0,6:do_nothing; {\.{LIG},\.{/LIG>}}
+ 5,11:zz:=y; {\.{LIG/>}, \.{/LIG/>>}}
+ 1,7:cc:=left_z; {\.{LIG/}, \.{/LIG/>}}
+ 2:cc:=right_z; {\.{/LIG}}
+ 3:cc:=both_z; {\.{/LIG/}}
+ end; {there are no other cases}
+ end
+
+@ Evaluation of $f(x,y)$ is handled by two mutually recursive procedures.
+Kind of a neat algorithm, generalizing a depth-first search.
+
+@p function f(@!h,@!x,@!y:index):index; forward;@t\2@>
+ {compute $f$ for arguments known to be in |hash[h]|}
+function eval(@!x,@!y:index):index; {compute $f(x,y)$ with hashtable lookup}
+var @!key:integer64; {value sought in hash table}
+begin key:=int64cast(xmax_char)*x+y+1; h:=(hash_mult*key) mod hash_size;
+while hash[h]>key do
+ if h>0 then decr(h)@+else h:=hash_size;
+if hash[h]<key then eval:=y {not in ordered hash table}
+else eval:=f(h,x,y);
+end;
+
+@ Pascal's beastly convention for |forward| declarations prevents us from
+saying |function f(h,x,y:index):index| here.
+
+@p function f;
+begin case class[h] of
+simple: do_nothing;
+left_z: begin class[h]:=pending; lig_z[h]:=eval(lig_z[h],y); class[h]:=simple;
+ end;
+right_z: begin class[h]:=pending; lig_z[h]:=eval(x,lig_z[h]); class[h]:=simple;
+ end;
+both_z: begin class[h]:=pending; lig_z[h]:=eval(eval(x,lig_z[h]),y);
+ class[h]:=simple;
+ end;
+pending: begin x_lig_cycle:=x; y_lig_cycle:=y; lig_z[h]:=xxmax_char; class[h]:=simple;
+ end; {the value |xxmax_char| will break all cycles, since it's not in |hash|}
+end; {there are no other cases}
+f:=lig_z[h];
+end;
+
+@* The main program.
+The routines sketched out so far need to be packaged into separate procedures,
+on some systems, since some \PASCAL\ compilers place a strict limit on the
+size of a routine. The packaging is done here in an attempt to avoid some
+system-dependent changes.
+
+First comes the |organize| procedure, which reads the input data and
+gets ready for subsequent events. If something goes wrong, the routine
+returns |false|.
+
+@p function organize:boolean;
+label final_end, 30;
+var tfm_ptr:index; {an index into |tfm|}
+begin @<Read the whole input file@>;@/
+@<Set subfile sizes |lh|, |bc|, \dots, |np|@>;@/
+@<Compute the base addresses@>;@/
+organize:=true; goto 30;
+final_end: organize:=false;
+30: end;
+
+@ Next we do the simple things.
+
+@p procedure do_simple_things;
+var i:integer; {an index to words of a subfile}
+begin @<Do the header@>;@/
+@<Do the parameters@>;@/
+@<Do the ivalue parameters@>;@/
+@<Do the fvalue parameters@>;@/
+@<Do the mvalue parameters@>;@/
+@<Do the rule parameters@>;@/
+@<Do the glue parameters@>;@/
+@<Do the penalty parameters@>;@/
+@<Check the |fix_word| entries@>@/
+end;
+
+@ And then there's a routine for individual characters.
+
+@p procedure do_characters;
+var @!c:integer; {character being done}
+@!k:index; {a random index}
+@!ai:0..lig_size; {index into |activity|}
+begin @<Do the characters@>;@/
+end;
+
+@ Here is where \.{TFtoPL} begins and ends.
+@p begin initialize;@/
+if not organize then goto final_end;
+do_simple_things;@/
+@<Do the ligatures and kerns@>;
+@<Check the extensible recipes@>;
+do_characters; print_ln('.');@/
+if level<>0 then print_ln('This program isn''t working!');
+@.This program isn't working@>
+if not perfect then
+ begin out('(COMMENT THE OFM FILE WAS BAD, SO THE DATA HAS BEEN CHANGED!)');
+@.THE OFM FILE WAS BAD...@>
+ write_ln(pl_file);
+ end;
+final_end:end.
+
+@* System-dependent changes.
+This section should be replaced, if necessary, by changes to the program
+that are necessary to make \.{TFtoPL} work at a particular installation.
+It is usually best to design your change file so that all changes to
+previous sections preserve the section numbering; then everybody's version
+will be consistent with the printed program. More extensive changes,
+which introduce new sections, can be inserted here; then only the index
+itself will get a new section number.
+@^system dependencies@>
+
+@* Index.
+Pointers to error messages appear here together with the section numbers
+where each ident\-i\-fier is used.