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 public $imagepath = 'images/tex';
40 public $latexbin = '/usr/bin/latex';
41 public $dvipsbin = '/usr/bin/dvips';
42 public $pstoimgbin = '/usr/bin/pstoimg';
44 function getDescription()
46 return _("Convert Tex mathematicals expressions to cached PNG files. This is for small text.");
49 function getDefaultArguments()
51 return array('text' => "$$(a + b)^2 = a^2 + 2 ab + b^2$$");
54 function parseArgStr($argstr)
56 // modified from WikiPlugin.php
61 $qq_p = '" ( (?:[^"\\\\]|\\\\.)* ) "';
62 //"<--kludge for brain-dead syntax coloring
63 $q_p = "' ( (?:[^'\\\\]|\\\\.)* ) '";
64 $gt_p = "_\\( $opt_ws $qq_p $opt_ws \\)";
65 $argspec_p = "($arg_p) $opt_ws ($op_p) $opt_ws (?: $qq_p|$q_p|$gt_p|($word_p))";
70 while (preg_match("/^$opt_ws $argspec_p $opt_ws/x", $argstr, $m)) {
71 @ list(, $arg, $op, $qq_val, $q_val, $gt_val, $word_val) = $m;
72 $argstr = substr($argstr, strlen($m[0]));
74 // Remove quotes from string values.
76 // we don't remove backslashes in tex formulas
77 // $val = stripslashes($qq_val);
80 $val = stripslashes($q_val); elseif ($gt_val)
81 $val = _(stripslashes($gt_val)); else
87 // NOTE: This does work for multiple args. Use the
88 // separator character defined in your webserver
89 // configuration, usually & or & (See
90 // http://www.htmlhelp.com/faq/cgifaq.4.html)
91 // e.g. <plugin RecentChanges days||=1 show_all||=0 show_minor||=0>
92 // url: RecentChanges?days=1&show_all=1&show_minor=0
94 $defaults[$arg] = $val;
99 $this->handle_plugin_args_cruft($argstr, $args);
102 return array($args, $defaults);
105 function createTexFile($texfile, $text)
107 // this is the small latex file
108 // which contains only the mathematical
110 $fp = fopen($texfile, 'w');
111 $str = "\documentclass{article}\n";
112 $str .= "\usepackage{amsfonts}\n";
113 $str .= "\usepackage{amssymb}\n";
114 // Here tou can add some package in order
115 // to produce more sophisticated output
116 $str .= "\pagestyle{empty}\n";
117 $str .= "\begin{document}\n";
118 $str .= $text . "\n";
119 $str .= "\end{document}";
125 function createPngFile($imagepath, $imagename)
127 // to create dvi file from the latex file
128 $commandes = $this->latexbin . " temp.tex;";
129 exec("cd $imagepath;$commandes");
130 // to create png file from the dvi file
131 // there is no option but it is possible
132 // to add one (scale for example)
133 if (file_exists("$imagepath/temp.dvi")) {
134 $commandes = $this->dvipsbin . " temp.dvi -o temp.ps;";
135 $commandes .= $this->pstoimgbin . " -type png -margins 0,0 ";
136 $commandes .= "-crop a -geometry 600x300 ";
137 $commandes .= "-aaliastext -color 1 -scale 1.5 ";
138 $commandes .= "temp.ps -o " . $imagename;
139 exec("cd $imagepath;$commandes");
140 unlink("$imagepath/temp.dvi");
141 unlink("$imagepath/temp.ps");
143 echo _(" (syntax error for latex) ");
144 // to clean the directory
145 unlink("$imagepath/temp.tex");
146 unlink("$imagepath/temp.aux");
147 unlink("$imagepath/temp.log");
151 function isMathExp(&$text)
153 // this function returns
154 // 0 : text is too long or not a mathematical expression
155 // 1 : text is $xxxxxx$ hence in line
156 // 2 : text is $$xxxx$$ hence centered
157 $last = strlen($text) - 1;
159 $text = "Too long !";
161 } elseif ($last <= 1 || strpos($text, '$') != 0) {
163 } elseif (strpos($text, '$', 1) == $last)
164 return 1; elseif ($last > 3 &&
165 strpos($text, '$', 1) == 1 &&
166 strpos($text, '$', 2) == $last - 1
172 function tex2png($text)
174 // the name of the png cached file
175 $imagename = md5($text) . ".png";
176 $url = $this->imagepath . "/$imagename";
178 if (!file_exists($url)) {
179 if (is_writable($this->imagepath)) {
180 $texfile = $this->imagepath . "/temp.tex";
181 $this->createTexFile($texfile, $text);
182 $this->createPngFile($this->imagepath, $imagename);
184 $error_html = _("TeX imagepath not writable.");
185 trigger_error($error_html, E_USER_NOTICE);
189 // there is always something in the html page
190 // even if the tex directory doesn't exist
191 // or mathematical expression is wrong
192 switch ($this->isMathExp($text)) {
193 case 0: // not a mathematical expression
194 $html = HTML::tt(array('class' => 'tex',
195 'style' => 'color:red;'), $text);
197 case 1: // an inlined mathematical expression
198 $html = HTML::img(array('class' => 'tex',
202 case 2: // mathematical expression on separate line
203 $html = HTML::img(array('class' => 'tex',
206 $html = HTML::div(array('align' => 'center'), $html);
215 function run($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);
230 return HTML::p($error_html);
239 // c-hanging-comment-ender-p: nil
240 // indent-tabs-mode: nil