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';
49 function getDescription()
51 return _("Convert Tex mathematicals expressions to cached PNG files. This is for small text.");
54 function getDefaultArguments()
56 return array('text' => "$$(a + b)^2 = a^2 + 2 ab + b^2$$");
59 function parseArgStr($argstr)
61 // modified from WikiPlugin.php
66 $qq_p = '" ( (?:[^"\\\\]|\\\\.)* ) "';
67 //"<--kludge for brain-dead syntax coloring
68 $q_p = "' ( (?:[^'\\\\]|\\\\.)* ) '";
69 $gt_p = "_\\( $opt_ws $qq_p $opt_ws \\)";
70 $argspec_p = "($arg_p) $opt_ws ($op_p) $opt_ws (?: $qq_p|$q_p|$gt_p|($word_p))";
75 while (preg_match("/^$opt_ws $argspec_p $opt_ws/x", $argstr, $m)) {
76 @ list(, $arg, $op, $qq_val, $q_val, $gt_val, $word_val) = $m;
77 $argstr = substr($argstr, strlen($m[0]));
79 // Remove quotes from string values.
81 // we don't remove backslashes in tex formulas
82 // $val = stripslashes($qq_val);
85 $val = stripslashes($q_val); elseif ($gt_val)
86 $val = _(stripslashes($gt_val)); else
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)
112 // this is the small latex file
113 // which contains only the mathematical
115 $fp = fopen($texfile, 'w');
116 $str = "\documentclass{article}\n";
117 $str .= "\usepackage{amsfonts}\n";
118 $str .= "\usepackage{amssymb}\n";
119 // Here tou can add some package in order
120 // to produce more sophisticated output
121 $str .= "\pagestyle{empty}\n";
122 $str .= "\begin{document}\n";
123 $str .= $text . "\n";
124 $str .= "\end{document}";
130 function createPngFile($imagepath, $imagename)
132 // to create dvi file from the latex file
133 $commandes = $this->latexbin . " temp.tex;";
134 exec("cd $imagepath;$commandes");
135 // to create png file from the dvi file
136 // there is no option but it is possible
137 // to add one (scale for example)
138 if (file_exists("$imagepath/temp.dvi")) {
139 $commandes = $this->dvipsbin . " temp.dvi -o temp.ps;";
140 $commandes .= $this->pstoimgbin . " -type png -margins 0,0 ";
141 $commandes .= "-crop a -geometry 600x300 ";
142 $commandes .= "-aaliastext -color 1 -scale 1.5 ";
143 $commandes .= "temp.ps -o " . $imagename;
144 exec("cd $imagepath;$commandes");
145 unlink("$imagepath/temp.dvi");
146 unlink("$imagepath/temp.ps");
148 echo _(" (syntax error for latex) ");
149 // to clean the directory
150 unlink("$imagepath/temp.tex");
151 unlink("$imagepath/temp.aux");
152 unlink("$imagepath/temp.log");
156 function isMathExp(&$text)
158 // this function returns
159 // 0 : text is too long or not a mathematical expression
160 // 1 : text is $xxxxxx$ hence in line
161 // 2 : text is $$xxxx$$ hence centered
162 $last = strlen($text) - 1;
164 $text = "Too long !";
166 } elseif ($last <= 1 || strpos($text, '$') != 0) {
168 } elseif (strpos($text, '$', 1) == $last)
169 return 1; elseif ($last > 3 &&
170 strpos($text, '$', 1) == 1 &&
171 strpos($text, '$', 2) == $last - 1
177 function tex2png($text)
179 // the name of the png cached file
180 $imagename = md5($text) . ".png";
181 $url = $this->imagepath . "/$imagename";
183 if (!file_exists($url)) {
184 if (is_writable($this->imagepath)) {
185 $texfile = $this->imagepath . "/temp.tex";
186 $this->createTexFile($texfile, $text);
187 $this->createPngFile($this->imagepath, $imagename);
189 $error_html = _("TeX imagepath not writable.");
190 trigger_error($error_html, E_USER_NOTICE);
194 // there is always something in the html page
195 // even if the tex directory doesn't exist
196 // or mathematical expression is wrong
197 switch ($this->isMathExp($text)) {
198 case 0: // not a mathematical expression
199 $html = HTML::tt(array('class' => 'tex',
200 'style' => 'color:red;'), $text);
202 case 1: // an inlined mathematical expression
203 $html = HTML::img(array('class' => 'tex',
207 case 2: // mathematical expression on separate line
208 $html = HTML::img(array('class' => 'tex',
211 $html = HTML::div(array('align' => 'center'), $html);
220 function run($dbi, $argstr, &$request, $basepage)
223 if ((function_exists('ImageTypes') and (ImageTypes() & IMG_PNG))
224 or function_exists("ImagePNG")
226 // we have gd & png so go ahead.
227 extract($this->getArgs($argstr, $request));
228 return $this->tex2png($text);
230 // we don't have png and/or gd.
231 $error_html = _("Sorry, this version of PHP cannot create PNG image files.");
232 $link = "http://www.php.net/manual/pl/ref.image.php";
233 $error_html .= sprintf(_("See %s"), $link) . ".";
234 trigger_error($error_html, E_USER_NOTICE);
235 return HTML::p($error_html);
244 // c-hanging-comment-ender-p: nil
245 // indent-tabs-mode: nil