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 along
19 * with PhpWiki; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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';
49 function getDescription()
51 return _("Convert Tex mathematicals expressions to cached png files." .
52 " This is for small text");
55 function getDefaultArguments()
57 return array('text' => "$$(a + b)^2 = a^2 + 2 ab + b^2$$");
60 function parseArgStr($argstr)
62 // modified from WikiPlugin.php
67 $qq_p = '" ( (?:[^"\\\\]|\\\\.)* ) "';
68 //"<--kludge for brain-dead syntax coloring
69 $q_p = "' ( (?:[^'\\\\]|\\\\.)* ) '";
70 $gt_p = "_\\( $opt_ws $qq_p $opt_ws \\)";
71 $argspec_p = "($arg_p) $opt_ws ($op_p) $opt_ws (?: $qq_p|$q_p|$gt_p|($word_p))";
76 while (preg_match("/^$opt_ws $argspec_p $opt_ws/x", $argstr, $m)) {
77 @ list(, $arg, $op, $qq_val, $q_val, $gt_val, $word_val) = $m;
78 $argstr = substr($argstr, strlen($m[0]));
80 // Remove quotes from string values.
82 // we don't remove backslashes in tex formulas
83 // $val = stripslashes($qq_val);
86 $val = stripslashes($q_val); elseif ($gt_val)
87 $val = _(stripslashes($gt_val)); else
93 // NOTE: This does work for multiple args. Use the
94 // separator character defined in your webserver
95 // configuration, usually & or & (See
96 // http://www.htmlhelp.com/faq/cgifaq.4.html)
97 // e.g. <plugin RecentChanges days||=1 show_all||=0 show_minor||=0>
98 // url: RecentChanges?days=1&show_all=1&show_minor=0
100 $defaults[$arg] = $val;
105 $this->handle_plugin_args_cruft($argstr, $args);
108 return array($args, $defaults);
111 function createTexFile($texfile, $text)
113 // this is the small latex file
114 // which contains only the mathematical
116 $fp = fopen($texfile, 'w');
117 $str = "\documentclass{article}\n";
118 $str .= "\usepackage{amsfonts}\n";
119 $str .= "\usepackage{amssymb}\n";
120 // Here tou can add some package in order
121 // to produce more sophisticated output
122 $str .= "\pagestyle{empty}\n";
123 $str .= "\begin{document}\n";
124 $str .= $text . "\n";
125 $str .= "\end{document}";
131 function createPngFile($imagepath, $imagename)
133 // to create dvi file from the latex file
134 $commandes = $this->latexbin . " temp.tex;";
135 exec("cd $imagepath;$commandes");
136 // to create png file from the dvi file
137 // there is no option but it is possible
138 // to add one (scale for example)
139 if (file_exists("$imagepath/temp.dvi")) {
140 $commandes = $this->dvipsbin . " temp.dvi -o temp.ps;";
141 $commandes .= $this->pstoimgbin . " -type png -margins 0,0 ";
142 $commandes .= "-crop a -geometry 600x300 ";
143 $commandes .= "-aaliastext -color 1 -scale 1.5 ";
144 $commandes .= "temp.ps -o " . $imagename;
145 exec("cd $imagepath;$commandes");
146 unlink("$imagepath/temp.dvi");
147 unlink("$imagepath/temp.ps");
149 echo _(" (syntax error for latex) ");
150 // to clean the directory
151 unlink("$imagepath/temp.tex");
152 unlink("$imagepath/temp.aux");
153 unlink("$imagepath/temp.log");
157 function isMathExp(&$text)
159 // this function returns
160 // 0 : text is too long or not a mathematical expression
161 // 1 : text is $xxxxxx$ hence in line
162 // 2 : text is $$xxxx$$ hence centered
163 $last = strlen($text) - 1;
165 $text = "Too long !";
167 } elseif ($last <= 1 || strpos($text, '$') != 0) {
169 } elseif (strpos($text, '$', 1) == $last)
170 return 1; elseif ($last > 3 &&
171 strpos($text, '$', 1) == 1 &&
172 strpos($text, '$', 2) == $last - 1
178 function tex2png($text)
180 // the name of the png cached file
181 $imagename = md5($text) . ".png";
182 $url = $this->imagepath . "/$imagename";
184 if (!file_exists($url)) {
185 if (is_writable($this->imagepath)) {
186 $texfile = $this->imagepath . "/temp.tex";
187 $this->createTexFile($texfile, $text);
188 $this->createPngFile($this->imagepath, $imagename);
190 $error_html = _("TeX imagepath not writable.");
191 trigger_error($error_html, E_USER_NOTICE);
195 // there is always something in the html page
196 // even if the tex directory doesn't exist
197 // or mathematical expression is wrong
198 switch ($this->isMathExp($text)) {
199 case 0: // not a mathematical expression
200 $html = HTML::tt(array('class' => 'tex',
201 'style' => 'color:red;'), $text);
203 case 1: // an inlined mathematical expression
204 $html = HTML::img(array('class' => 'tex',
208 case 2: // mathematical expression on separate line
209 $html = HTML::img(array('class' => 'tex',
212 $html = HTML::div(array('align' => 'center'), $html);
221 function run($dbi, $argstr, &$request, $basepage)
224 if ((function_exists('ImageTypes') and (ImageTypes() & IMG_PNG))
225 or function_exists("ImagePNG")
227 // we have gd & png so go ahead.
228 extract($this->getArgs($argstr, $request));
229 return $this->tex2png($text);
231 // we don't have png and/or gd.
232 $error_html = _("Sorry, this version of PHP cannot create PNG image files.");
233 $link = "http://www.php.net/manual/pl/ref.image.php";
234 $error_html .= sprintf(_("See %s"), $link) . ".";
235 trigger_error($error_html, E_USER_NOTICE);
247 // c-hanging-comment-ender-p: nil
248 // indent-tabs-mode: nil