3 # eqn2graph -- compile EQN equation descriptions to bitmap images
5 # by Eric S. Raymond <esr@thyrsus.com>, July 2002
7 # In Unixland, the magic is in knowing what to string together...
9 # Take an eqn equation on stdin, emit cropped bitmap on stdout.
10 # The pic markup should *not* be wrapped in .EQ/.EN, this script will do that.
11 # A -U option on the command line enables gpic/groff "unsafe" mode.
12 # A -format FOO option changes the image output format to any format
13 # supported by convert(1). All other options are passed to convert(1).
14 # The default format is PNG.
16 # This is separate from pic2graph because pic processing has some weird
17 # clipping effect on the output, mangling equations that are very wide
18 # or deep. Besides, this tool can supply its own delimiters.
21 # Requires the groff suite and the ImageMagick tools. Both are open source.
22 # This code is released to the public domain.
24 # Here are the assumptions behind the option processing:
26 # 1. None of the options of eqn(1) are relevant.
28 # 2. Only the -U option of groff(1) is relevant.
30 # 3. Many options of convert(1) are potentially relevant, (especially
31 # -density, -interlace, -transparency, -border, and -comment).
33 # Thus, we pass -U to groff(1), and everything else to convert(1).
35 # $Id: eqn2graph.sh,v 1.2 2002/07/17 04:55:46 wlemb Exp $
50 echo "GNU eqn2graph (groff) version @VERSION@"
53 echo "usage: eqn2graph [ option ...] < in > out"
56 convert_opts="$convert_opts $1";;
63 # 2. Process through eqn(1) to emit troff markup.
64 # 3. Process through groff(1) to emit Postscript.
65 # 4. Use convert(1) to crop the Postscript and turn it into a bitmap.
66 tmp=/usr/tmp/eqn2graph-$$
67 trap "rm ${tmp}.*" 0 2 15
69 (echo ".EQ"; echo 'delim $$'; echo ".EN"; echo '$'"${equation}"'$') | \
70 groff -e $groff_opts -Tps >${tmp}.ps \
71 && convert -crop 0x0 $convert_opts ${tmp}.ps ${tmp}.${format} \
72 && cat ${tmp}.${format}