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: pic2graph.sh,v 1.7 2005/05/18 07:03:07 wl Exp $
36#
37groffpic_opts=""
38gs_opts=""
39convert_opts=""
40format="png"
41eqndelim='$$'
42
43while [ "$1" ]
44do
45    case $1 in
46    -unsafe)
47	groffpic_opts="-U";;
48    -format)
49	format=$2
50	shift;;
51    -eqn)
52	eqndelim=$2
53	shift;;
54    -v | --version)
55	echo "GNU pic2graph (groff) version @VERSION@"
56	exit 0;;
57    --help)
58	echo "usage: pic2graph [ option ...] < in > out"
59	exit 0;;
60    *)
61	convert_opts="$convert_opts $1";;
62    esac
63    shift
64done
65
66if [ "$eqndelim" ]
67then
68    eqndelim="delim $eqndelim"
69fi
70
71# create temporary directory
72tmp=
73for d in "$GROFF_TMPDIR" "$TMPDIR" "$TMP" "$TEMP" /tmp; do
74    test -z "$d" && continue
75
76    tmp=`(umask 077 && mktemp -d -q "$d/pic2graph-XXXXXX") 2> /dev/null` \
77    && test -n "$tmp" && test -d "$tmp" \
78    && break
79
80    tmp=$d/pic2graph$$-$RANDOM
81    (umask 077 && mkdir $tmp) 2> /dev/null \
82    && break
83done;
84if test -z "$tmp"; then
85    echo "$0: cannot create temporary directory" >&2
86    { (exit 1); exit 1; }
87fi
88
89trap 'exit_status=$?; rm -rf $tmp && exit $exit_status' 0 2 15 
90
91# Here goes:
92# 1. Wrap the input in dummy .PS/PE macros (and add possibly null .EQ/.EN)
93# 2. Process through eqn and pic to emit troff markup.
94# 3. Process through groff to emit Postscript.
95# 4. Use convert(1) to crop the PostScript and turn it into a bitmap.
96(echo ".EQ"; echo $eqndelim; echo ".EN"; echo ".PS"; cat; echo ".PE") | \
97    groff -e -p $groffpic_opts -Tps -P-pletter > $tmp/pic2graph.ps \
98    && convert -trim -crop 0x0 $convert_opts $tmp/pic2graph.ps $tmp/pic2graph.$format \
99    && cat $tmp/pic2graph.$format
100
101# End
102