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Diffstat (limited to 'IkiWiki/Plugin/teximg.pm')
| -rw-r--r-- | IkiWiki/Plugin/teximg.pm | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/IkiWiki/Plugin/teximg.pm b/IkiWiki/Plugin/teximg.pm new file mode 100644 index 000000000..1993249eb --- /dev/null +++ b/IkiWiki/Plugin/teximg.pm @@ -0,0 +1,183 @@ +#!/usr/bin/perl +# Licensed under GPL v2 or greater +# (c) 2007 Patrick Winnertz <patrick.winnertz@skolelinux.org> + +package IkiWiki::Plugin::teximg; +use warnings; +use strict; +use Digest::MD5 qw(md5_hex); +use File::Temp qw(tempdir); +use URI::Escape qw(uri_escape); +use IkiWiki 2.00; + +sub import { #{{{ + hook(type => "preprocess", id => "teximg", call => \&preprocess); +} #}}} + +sub preprocess (@) { #{{{ + my %params = @_; + + my $height = $params{height}; + if (! defined $height || ! length $height) { + $height = 12; + } + else { + $height =~ s#(\d+)#$1#; + } + + my $code = $params{code}; + if (! defined $code && ! length $code) { + return "[[teximg ".gettext("missing tex code"). "]]"; + } + + if (check($code)) { + return create($code, check_height($height), \%params); + } + else { + return "[[teximg ".gettext("code includes disallowed latex commands"). "]]"; + } +} #}}} + +sub check_height ($) { #{{{ + # Since latex doesn't support unlimited scaling this function + # returns the closest supported size. + my $height =shift; + + my @allowed=(8,9,10,11,12,14,17,20); + + my $ret; + my $fit; + foreach my $val (@allowed) { + my $f = abs($val - $height); + if (! defined($fit) || $f < $fit ) { + $ret=$val; + $fit=$f; + } + } + return $ret; +} #}}} + +sub create ($$$) { #{{{ + # This function calls the image generating function and returns + # the <img .. /> for the generated image. + my $code = shift; + my $height = shift; + my $params = shift; + + if (! defined($height) and not length($height) ) { + $height = 12; + } + + my $digest = md5_hex($code, $height); + + my $teximgdir = "/teximag"; + my $imglink = "$teximgdir/$digest.png"; + my $imglog = "$teximgdir/$digest.log"; + will_render($params->{destpage}, $imglink); + will_render($params->{destpage}, $imglog); + + my $imgurl; + my $logurl; + if (! $params->{preview}) { + $imgurl = urlto($imglink, $params->{destpage}); + $logurl = urlto($imglog, $params->{destpage}); + } + else { + $imgurl="$config{url}/$teximgdir/$digest.png"; + $logurl="$config{url}/$teximgdir/$digest.log"; + } + + if (-e "$config{destdir}/$imglink" || + gen_image($code, $height, $digest, $teximgdir)) { + return qq{<img src="$imgurl" alt="} + .(exists $params{alt} ? $params{alt} : uri_escape($code)) + .qq{" class="teximg" />}; + } + else { + return qq{[[teximg <a href="$logurl">}.gettext("failed to generate image from code")."</a>]]"; + } +} #}}} + +sub gen_image ($$$$) { #{{{ + # Actually creates the image. + my $code = shift; + my $height = shift; + my $digest = shift; + my $imagedir = shift; + + #TODO This should move into the setup file. + my $tex = '\documentclass['.$height.'pt]{scrartcl}'; + $tex .= '\usepackage[version=3]{mhchem}'; + $tex .= '\usepackage{amsmath}'; + $tex .= '\usepackage{amsfonts}'; + $tex .= '\usepackage{amssymb}'; + $tex .= '\pagestyle{empty}'; + $tex .= '\begin{document}'; + $tex .= '$$'.$code.'$$'; + $tex .= '\end{document}'; + + my $tmp = eval { create_tmp_dir($digest) }; + if (! $@ && + writefile("$digest.tex", $tmp, $tex) && + system("cd $tmp; latex --interaction=nonstopmode $tmp/$digest.tex > /dev/null") == 0 && + system("dvips -E $tmp/$digest.dvi -o $tmp/$digest.ps 2> $tmp/$digest.log") == 0 && + # ensure destination directory exists + writefile("$imagedir/$digest.png", $config{destdir}, "") && + system("convert -density 120 -trim -transparent \"#FFFFFF\" $tmp/$digest.ps $config{destdir}/$imagedir/$digest.png > $tmp/$digest.log") == 0) { + return 1; + } + else { + # store failure log + my $log; + { + open(my $f, '<', "$tmp/$digest.log"); + local $/=undef; + $log = <$f>; + close($f); + } + writefile("$digest.log", "$config{destdir}/$imagedir", $log); + + return 0; + } +} #}}} + +sub create_tmp_dir ($) { #{{{ + # Create a temp directory, it will be removed when ikiwiki exits. + my $base = shift; + + my $template = $base.".XXXXXXXXXX"; + my $tmpdir = tempdir($template, TMPDIR => 1, CLEANUP => 1); + return $tmpdir; +} #}}} + +sub check ($) { #{{{ + # Check if the code is ok + my $code = shift; + + my @badthings = ( + qr/\$\$/, + qr/\\include/, + qr/\\includegraphic/, + qr/\\usepackage/, + qr/\\newcommand/, + qr/\\renewcommand/, + qr/\\def/, + qr/\\input/, + qr/\\open/, + qr/\\loop/, + qr/\\errorstopmode/, + qr/\\scrollmode/, + qr/\\batchmode/, + qr/\\read/, + qr/\\write/, + ); + + foreach my $thing (@badthings) { + if ($code =~ m/$thing/ ) { + return 0; + } + } + return 1; +} #}}} + +1 |