contrib/pic2graph/pic2graph.sh

   1 #!/bin/sh
   2 #
   3 # pic2graph -- compile PIC image descriptions to bitmap images
   4 #
   5 # by Eric S. Raymond <esr@thyrsus.com>, July 2002
   6
   7 # In Unixland, the magic is in knowing what to string together...
   8 #
   9 # Take a pic/eqn diagram on stdin, emit cropped bitmap on stdout.
  10 # The pic markup should *not* be wrapped in .PS/.PE, this script will do that.
  11 # An -unsafe 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).  An -eqn option changes the eqn delimiters.
  14 # All other options are passed to convert(1).  The default format in PNG.
  15 #
  16 # Requires the groff suite and the ImageMagick tools.  Both are open source.
  17 # This code is released to the public domain.
  18 #
  19 # Here are the assumptions behind the option processing:
  20 #
  21 # 1. Only the -U option of gpic(1) is relevant.  -C doesn't matter because
  22 #    we're generating our own .PS/.PE, -[ntcz] are irrelevant because we're
  23 #    generating Postscript.
  24 #
  25 # 2. Ditto for groff(1), though it's a longer and more tedious demonstration.
  26 #
  27 # 3. Many options of convert(1) are potentially relevant (especially
  28 #    -density, -interlace, -transparency, -border, and -comment).
  29 #
  30 # Thus, we pass -U to gpic and groff, and everything else to convert(1).
  31 #
  32 # We don't have complete option coverage on eqn because this is primarily
  33 # intended as a pic translator; we can live with eqn defaults.
  34 #
  35 # $Id$
  36 #
  37 groffpic_opts=""
  38 gs_opts=""
  39 convert_opts=""
  40 format="png"
  41 eqndelim='$$'
  42
  43 while [ "$1" ]
  44 do
  45     case $1 in
  46     -unsafe)
  47         groffpic_opts="-U";;
  48     -format)
  49         format=$2
  50         shift;;
  51     -eqn)
  52         eqndelim=$2
  53         shift;;
  54     -v | --version)
  55         echo "GNU pic2graph (groff) version @VERSION@"
  56         exit 0;;
  57     --help)
  58         echo "usage: pic2graph [ option ...] < in > out"
  59         exit 0;;
  60     *)
  61         convert_opts="$convert_opts $1";;
  62     esac
  63     shift
  64 done
  65
  66 if [ "$eqndelim" ]
  67 then
  68     eqndelim="delim $eqndelim"
  69 fi
  70
  71 # Here goes:
  72 # 1. Wrap the input in dummy .PS/PE macros (and add possibly null .EQ/.EN)
  73 # 2. Process through eqn and pic to emit troff markup.
  74 # 3. Process through groff to emit Postscript.
  75 # 4. Use convert(1) to crop the PostScript and turn it into a bitmap.
  76 tmp=/usr/tmp/pic2graph-$$
  77 trap "rm ${tmp}.*" 0 2 15
  78 (echo ".EQ"; echo $eqndelim; echo ".EN"; echo ".PS"; cat; echo ".PE") | \
  79        groff -e -p $groffpic_opts -Tps >${tmp}.ps \
  80        && convert -crop 0x0 $convert_opts ${tmp}.ps ${tmp}.${format} \
  81        && cat ${tmp}.${format}
  82
  83 # End