#!/usr/local/bin/perl

# Title:	extract-figures.pl
# Version:	3
# Synopsis:	extracts TeX figures from Texinfo files, makes JPEG files
# Author:	Geoffrey S. Knauth <gknauth@bbn.com>
# Created:	20-May-1996
# Note:		See brief documentation at bottom.
#
# Copyright (C) 1996  Geoffrey S. Knauth
# Distribution under the terms of the GNU General Public License (see bottom).

$in_tex = false;
$in_tex_code = false;
while (<>) {
    chop;
    $line = $_;
    if (/^\@tex/) {
	$in_tex = true;
    }
    if ($in_tex eq true && /^%\s+texpiece\s+(\S+)\s+(\d+)/) {
	$in_tex_code = true;
	$name = $1;
	$magstep = $2;
	$tex_name = $name . ".tex";
	print "----- writing $tex_name\n";
	open (TEX, ">$tex_name");
	print TEX "% $tex_name\n";
	print TEX
	  "% This file was automatically generated by `extract-figures.pl'.\n";
	print TEX "\\nopagenumbers\n\n";
	next;
    }
    if ($in_tex_code eq true && /^\@end tex/) {
	$in_tex_code = $in_tex = false;
	print TEX "\n\\bye\n";
	close TEX;
	&do_command ("tex $name.tex");
	&do_command ("rm $name.tex");
	&do_command ("dvips -E -x $magstep -o $name.eps $name.dvi");
	&do_command ("rm $name.dvi");
	&do_command ("convert -monochrome $name.eps $name.jpg");
    }
    if ($in_tex_code eq true) {
	print TEX $_, "\n";
    }
}
exit 0;

sub do_command {
    local ($command) = $_[0];
    print "$command\n";
    system ($command);
}

__END__
		       HOW TO USE THIS PROGRAM

   Note: I am not currently using this program.  But it was useful at
one point, so I'm making it available to you.  I used the program to
embed TeX code for tables in Texinfo source.  I did it like this:

	...texinfo stuff
	@ignore
	% texpiece NAME1 1000
	...TeX code to generate NAME1.tex,
	...leading to NAME1.eps at magstep 1000
	@end ignore
	...more texinfo stuff
	@ignore
	% texpiece NAME2 1440
	...TeX code to generate NAME2.tex,
	...leading to NAME2.eps at magstep 1440
	@end ignore
	...more textinfo stuff

   I used `texi2html' and C-c C-t C-b (in Emacs Texinfo mode) to make
HTML pages and info files, respectively, from Texinfo source.
`extract-figures.pl' helped me create Encapsulated Postscript Files,
which I then turned into GIF/JPEG files with `convert' so that my web
pages could reference the images.

   The reason I stopped using this program is that my colleague Andy
Lee correctly pointed out that since my graphics were just tables, I
should produce HTML tables to speed downloads and improve appearances.
I then wrote `gentable.pl' and `expand-tables.pl'.

		     LICENSE TO USE THIS SOFTWARE

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

	Free Software Foundation
	59 Temple Place - Suite 330
	Boston, MA  02111-1307
	Voice:  +1-617-542-5942
	Fax:    +1-617-542-2652
	<ftp://prep.ai.mit.edu:/pub/gnu/COPYING>