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Diffstat (limited to 'contrib/eqn2graph/eqn2graph.sh')
| -rw-r--r-- | contrib/eqn2graph/eqn2graph.sh | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/contrib/eqn2graph/eqn2graph.sh b/contrib/eqn2graph/eqn2graph.sh new file mode 100644 index 00000000..5f58cb58 --- /dev/null +++ b/contrib/eqn2graph/eqn2graph.sh @@ -0,0 +1,63 @@ +#!/bin/sh +# +# eqn2graph -- compile EQN equation descriptions to bitmap images +# +# by Eric S. Raymond <esr@thyrsus.com>, July 2002 +# +# In Unixland, the magic is in knowing what to string together... +# +# Take an eqn equation on stdin, emit cropped bitmap on stdout. +# The pic markup should *not* be wrapped in .EQ/.EN, this script will do that. +# A -U option on the command line enables gpic/groff "unsafe" mode. +# All other options are passed to convert (or whichever back end is selected +# by the format option). The default format is PNG. +# +# This is separate from pic2graph because pic processing has some weird +# clipping effect on the output, mangling equations that are very wide +# or deep. Besides, this rool can supply its own delimiters. +# + +# Requires the groff suite and the ImageMagick tools. Both are open source. +# This code is released to the public domain. +# +# Here are the assumptions behind the option processing: +# +# 1. None of the options of eqn(1) are relevant. +# +# 2. Only the -U option of groff(1) is relevant. +# +# 3. Many options of convert(1) are potentially relevant, (especially +# -density, -interlace, -transparency, -border, and -comment). +# +# Thus, we pass -U to groff(1), and everything else to convert(1). +# +# $Id: eqn2graph.sh,v 1.1.1.1 2002/07/07 22:14:56 wlemb Exp $ +# +groff_opts="" +convert_opts="" +format="png" + +while [ "$1" ] +do + case $1 in + -unsafe) groff_opts="-U";; + -format) format=$2; shift;; + *) convert_opts="$convert_opts $1" ;; + esac + shift; +done + +# Here goes: +# 1. Add .EQ/.EN. +# 2. Process through eqn(1) to emit troff markup. +# 3. Process through groff(1) to emit Postscript. +# 4. Use convert(1) to crop the Postscript and turn it into a bitmap. +tmp=/usr/tmp/eqn2graph-$$ +trap "rm ${tmp}.*" 0 2 15 +read equation +(echo ".EQ"; echo 'delim $$'; echo ".EN"; echo '$'"${equation}"'$') | \ + groff -e $groff_opts -Tps >${tmp}.ps \ + && convert -crop 0x0 $convert_opts ${tmp}.ps ${tmp}.${format} \ + && cat ${tmp}.${format} + +# End |