4 * Copyright (C) Copyright 2004 Pierrick Meignen
6 * This file is part of PhpWiki.
8 * PhpWiki is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * PhpWiki is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with PhpWiki; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 * This is a simple version of the original TexToPng plugin which uses
25 * the powerful plugincached mechanism.
26 * TeX2png uses its own much simplier static cache in images/tex.
28 * @author: Pierrick Meignen
29 * TODO: use url helpers, windows fixes
30 * use a better imagepath
34 // LaTeX2HTML ftp://ftp.dante.de/tex-archive/support/latex2html
36 class WikiPlugin_TeX2png
39 var $imagepath = 'images/tex';
40 var $latexbin = '/usr/bin/latex';
41 var $dvipsbin = '/usr/bin/dvips';
42 var $pstoimgbin = '/usr/bin/pstoimg';
48 function getDescription () {
49 return _("Convert Tex mathematicals expressions to cached png files." .
50 " This is for small text");
53 function getDefaultArguments() {
54 return array('text' => "$$(a + b)^2 = a^2 + 2 ab + b^2$$");
57 function parseArgStr($argstr) {
58 // modified from WikiPlugin.php
63 $qq_p = '" ( (?:[^"\\\\]|\\\\.)* ) "';
64 //"<--kludge for brain-dead syntax coloring
65 $q_p = "' ( (?:[^'\\\\]|\\\\.)* ) '";
66 $gt_p = "_\\( $opt_ws $qq_p $opt_ws \\)";
67 $argspec_p = "($arg_p) $opt_ws ($op_p) $opt_ws (?: $qq_p|$q_p|$gt_p|($word_p))";
72 while (preg_match("/^$opt_ws $argspec_p $opt_ws/x", $argstr, $m)) {
73 @ list(,$arg,$op,$qq_val,$q_val,$gt_val,$word_val) = $m;
74 $argstr = substr($argstr, strlen($m[0]));
76 // Remove quotes from string values.
78 // we don't remove backslashes in tex formulas
79 // $val = stripslashes($qq_val);
82 $val = stripslashes($q_val);
84 $val = _(stripslashes($gt_val));
92 // NOTE: This does work for multiple args. Use the
93 // separator character defined in your webserver
94 // configuration, usually & or & (See
95 // http://www.htmlhelp.com/faq/cgifaq.4.html)
96 // e.g. <plugin RecentChanges days||=1 show_all||=0 show_minor||=0>
97 // url: RecentChanges?days=1&show_all=1&show_minor=0
99 $defaults[$arg] = $val;
104 $this->handle_plugin_args_cruft($argstr, $args);
107 return array($args, $defaults);
110 function createTexFile($texfile, $text) {
111 // this is the small latex file
112 // which contains only the mathematical
114 $fp = fopen($texfile, 'w');
115 $str = "\documentclass{article}\n";
116 $str .= "\usepackage{amsfonts}\n";
117 $str .= "\usepackage{amssymb}\n";
118 // Here tou can add some package in order
119 // to produce more sophisticated output
120 $str .= "\pagestyle{empty}\n";
121 $str .= "\begin{document}\n";
122 $str .= $text . "\n";
123 $str .= "\end{document}";
129 function createPngFile($imagepath, $imagename) {
130 // to create dvi file from the latex file
131 $commandes = $this->latexbin . " temp.tex;";
132 exec("cd $imagepath;$commandes");
133 // to create png file from the dvi file
134 // there is no option but it is possible
135 // to add one (scale for example)
136 if (file_exists("$imagepath/temp.dvi")){
137 $commandes = $this->dvipsbin . " temp.dvi -o temp.ps;";
138 $commandes .= $this->pstoimgbin . " -type png -margins 0,0 ";
139 $commandes .= "-crop a -geometry 600x300 ";
140 $commandes .= "-aaliastext -color 1 -scale 1.5 ";
141 $commandes .= "temp.ps -o " . $imagename;
142 exec("cd $imagepath;$commandes");
143 unlink("$imagepath/temp.dvi");
144 unlink("$imagepath/temp.ps");
146 echo _(" (syntax error for latex) ");
147 // to clean the directory
148 unlink("$imagepath/temp.tex");
149 unlink("$imagepath/temp.aux");
150 unlink("$imagepath/temp.log");
154 function isMathExp(&$text) {
155 // this function returns
156 // 0 : text is too long or not a mathematical expression
157 // 1 : text is $xxxxxx$ hence in line
158 // 2 : text is $$xxxx$$ hence centered
159 $last = strlen($text) - 1;
161 $text = "Too long !";
163 } elseif($last <= 1 || strpos($text, '$') != 0){
165 } elseif(strpos($text, '$', 1) == $last)
168 strpos($text, '$', 1) == 1 &&
169 strpos($text, '$', 2) == $last - 1)
174 function tex2png($text) {
175 // the name of the png cached file
176 $imagename = md5($text) . ".png";
177 $url = $this->imagepath . "/$imagename";
179 if(!file_exists($url)){
180 if(is_writable($this->imagepath)){
181 $texfile = $this->imagepath . "/temp.tex";
182 $this->createTexFile($texfile, $text);
183 $this->createPngFile($this->imagepath, $imagename);
185 $error_html = _("TeX imagepath not writable.");
186 trigger_error($error_html, E_USER_NOTICE);
190 // there is always something in the html page
191 // even if the tex directory doesn't exist
192 // or mathematical expression is wrong
193 switch($this->isMathExp($text)) {
194 case 0: // not a mathematical expression
195 $html = HTML::tt(array('class'=>'tex',
196 'style'=>'color:red;'), $text);
198 case 1: // an inlined mathematical expression
199 $html = HTML::img(array('class'=>'tex',
203 case 2: // mathematical expression on separate line
204 $html = HTML::img(array('class'=>'tex',
207 $html = HTML::div(array('align' => 'center'), $html);
216 function run($dbi, $argstr, &$request, $basepage) {
218 if ((function_exists('ImageTypes') and (ImageTypes() & IMG_PNG))
219 or function_exists("ImagePNG"))
221 // we have gd & png so go ahead.
222 extract($this->getArgs($argstr, $request));
223 return $this->tex2png($text);
225 // we don't have png and/or gd.
226 $error_html = _("Sorry, this version of PHP cannot create PNG image files.");
227 $link = "http://www.php.net/manual/pl/ref.image.php";
228 $error_html .= sprintf(_("See %s"), $link) .".";
229 trigger_error($error_html, E_USER_NOTICE);
239 // c-hanging-comment-ender-p: nil
240 // indent-tabs-mode: nil