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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 | <?php/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- *//*# ***** BEGIN LICENSE BLOCK *****# This file is part of Plume Framework, a simple PHP Application Framework.# Copyright (C) 2001-2007 Loic d'Anterroches and contributors.## Plume Framework is free software; you can redistribute it and/or modify# it under the terms of the GNU Lesser General Public License as published by# the Free Software Foundation; either version 2.1 of the License, or# (at your option) any later version.## Plume Framework is distributed in the hope that it will be useful,# but WITHOUT ANY WARRANTY; without even the implied warranty of# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the# GNU Lesser General Public License for more details.## You should have received a copy of the GNU Lesser General Public License# along with this program; if not, write to the Free Software# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA## ***** END LICENSE BLOCK ***** *//** * Given a shunk of a latex equation code, render it and return a * corresponding image file. * * Based on code by: * Benjamin Zeiss * Copyright (C) 2003 Benjamin Zeiss <zeiss@math.uni-goettingen.de> * Kjell Magne Fauske * * Example usage: * * $latex = new Pluf_Text_Latex_Equation(); * if (true === $latex->render('e = mc^2')) { * $png_file = $latex->output_file; * $png_full_path = $latex->output_path; * } else { * $error = $latex->error_code; * $msg = $latex->error_msg; * } * * Note that the class is not using exception to return the errors, * that way you can easily grab the error and depending on the error * code/message generate a special .png file to display. */class Pluf_Text_Latex_Equation { public $tmp_dir = '/tmp'; public $output_dir = '/tmp'; public $encoding = 'utf-8'; public $fragment = ''; public $latex_path = '/usr/bin/latex'; public $dvipng_path = '/usr/bin/dvipng'; public $resolution = '120'; public $bg_color = 'ffffff'; public $debug = false; /** * Black listing of tags. * * this most certainly needs to be extended. in the long term it * is planned to use a positive list for more security. this is * hopefully enough for now. i'd be glad to receive more bad tags * ! */ public $tags_blacklist = array( 'include', 'def', 'command', 'loop', 'repeat', 'open', 'toks', 'output', 'input', 'catcode', 'name', '^^', '\\every', '\\errhelp', '\\errorstopmode', '\\scrollmode', '\\nonstopmode', '\\batchmode', '\\read', '\\write', 'csname', '\\newhelp', '\\uppercase', '\\lowercase', '\\relax', '\\aftergroup', '\\afterassignment', '\\expandafter', '\\noexpand', '\\special'); public $error_code = 0; public $error_msg = ''; /* var $_latex_path = "/usr/local/bin/latex"; var $_dvips_path = "/usr/local/bin/dvips"; var $_convert_path = "/usr/local/bin/convert"; var $_identify_path="/usr/local/bin/identify"; var $_formula_density = 100; // originally 110 var $_xsize_limit = 700; var $_ysize_limit = 1000; var $_string_length_limit = 1000; var $_font_size = 10; var $_latexclass = "article"; //install extarticle class if you wish to have smaller font sizes var $_tmp_filename; var $_image_format = "png"; //change to png if you prefer ); var $_errorcode = 0; var $_errorextra = ''; */ /** * Initializes the class * * @param string Output directory (null) * @param string Temp directory (null) */ public function __construct($output_dir=null, $tmp_dir=null) { if (!is_null($output_dir)) { $this->output_dir = $output_dir; } if (!is_null($tmp_dir)) { $this->tmp_dir = $tmp_dir; } } /** * Tries to match the LaTeX Formula given as argument against the * formula cache. If the picture has not been rendered before, it'll * try to render the formula and drop it in the picture cache directory. * * @param string formula in LaTeX format * @returns the webserver based URL to a picture which contains the * requested LaTeX formula. If anything fails, the resultvalue is false. */ function getFormulaURL($latex_formula) { // circumvent certain security functions of web-software which // is pretty pointless right here $latex_formula = preg_replace("/>/i", ">", $latex_formula); $latex_formula = preg_replace("/</i", "<", $latex_formula); $formula_hash = md5($latex_formula.$this->_font_size); $filename = $formula_hash.".".$this->_image_format; $full_path_filename = $this->getPicturePath()."/".$filename; if (is_file($full_path_filename)) { return $this->getPicturePathHTTPD()."/".$filename; } else { // security filter: reject too long formulas if (strlen($latex_formula) > $this->_string_length_limit) { $this->_errorcode = 1; return false; } // security filter: try to match against LaTeX-Tags Blacklist for ($i=0;$i<sizeof($this->_latex_tags_blacklist);$i++) { if (stristr($latex_formula,$this->_latex_tags_blacklist[$i])) { $this->_errorcode = 2; return false; } } // security checks assume correct formula, let's render it if ($this->renderLatex($latex_formula)) { return $this->getPicturePathHTTPD()."/".$filename; } else { // uncomment if required //$this->_errorcode = 3; return false; } } } /** * Get the Latex preamble. * * You can overwrite this function if you want. * * @return string Latex preamble. */ function getPreamble() { return '\documentclass{article}'."\n" .'\usepackage{amsmath}'."\n" .'\usepackage{amsthm}'."\n" .'\usepackage{amssymb}'."\n" .'\usepackage{bm}'."\n" .'% \newcommand{\mx}[1]{\mathbf{\bm{#1}}} % Matrix command'."\n" .'% \newcommand{\vc}[1]{\mathbf{\bm{#1}}} % Vector command'."\n" .'% \newcommand{\T}{\text{T}} % Transpose'."\n" .'\pagestyle{empty}'."\n" .'\begin{document}'."\n"; } /** * Renders a LaTeX formula by the using the following method: * - write the formula into a wrapped tex-file in a temporary directory * and change to it * - Create a DVI file using latex (tetex) * - Convert DVI file to png or gif using dvipng * - Save the resulting image to the picture cache directory using an * md5 hash as filename. Already rendered formulas can be found directly * this way. * * @param string LaTeX formula * @param bool Render an inline formulat (false) * @return true if the picture has been successfully saved to the picture * cache directory */ function render($latex_formula, $inline=false) { $this->output_file = ''; $this->output_path = ''; $this->error_code = 0; $this->error_msg = ''; $output_file = $this->getOutputFile($latex_formula, $inline); if (file_exists($this->output_dir.'/'.$output_file)) { $this->output_file = $output_file; $this->output_path = $this->output_dir.'/'.$output_file; return true; } if (!$this->isCleanLatex($latex_formula)) { // error code and message set by the method return false; } if ($inline) { $body = sprintf("$%s$ \n \\newpage \n", $latex_formula); } else { $body = sprintf("\\[\n%s \n\\] \n \\newpage \n", $latex_formula); } $latex_document = $this->getPreamble().$body; $latex_document .= '\end{document}'; $current_dir = getcwd(); chdir($this->tmp_dir); // create temporary latex file $tmp_filename = md5($latex_formula.rand()); $fp = fopen($this->tmp_dir.'/'.$tmp_filename.'.tex', 'a+'); fputs($fp, $latex_document); fclose($fp); // create temporary dvi file $command = $this->latex_path.' --interaction=nonstopmode '.$tmp_filename.'.tex'; exec($command); if (!is_file($tmp_filename.'.dvi')) { $this->clean($tmp_filename); chdir($current_dir); $this->error_code = 4; $this->error_msg = __('Unable to generate the dvi file.'); return false; } // convert dvi file to png using dvipng $bg = 'rgb '; $_r = sprintf('%01.2f', hexdec(substr($this->bg_color, 0, 2))/255); $_g = sprintf('%01.2f', hexdec(substr($this->bg_color, 2, 2))/255); $_b = sprintf('%01.2f', hexdec(substr($this->bg_color, 4, 2))/255); $command = $this->dvipng_path.' -q -T tight -D '.$this->resolution.' -z 9 -pp -1 -bg "rgb '.$_r.' '.$_g.' '.$_b.'" -bg transparent ' .'-o %s.png %s.dvi'; $command = sprintf($command, $tmp_filename, $tmp_filename); exec($command); if (!is_file($tmp_filename.'.png')) { $this->clean($tmp_filename); chdir($current_dir); $this->error_code = 5; $this->error_msg = __('Unable to generate the png file.'); return false; } $output_file = $this->getOutputFile($latex_formula, $inline); $output_path = $this->output_dir.'/'.$output_file; if (false == rename($tmp_filename.'.png', $output_path) or !is_file($output_path)) { $this->clean($tmp_filename); chdir($current_dir); $this->error_code = 6; $this->error_msg = __('Unable to move the png file.'); return false; } $this->clean($tmp_filename); $this->output_file = $output_file; $this->output_path = $output_path; chdir($current_dir); return true; } /** * Cleans the temporary directory */ public function clean($tmp_filename) { if ($this->debug) return; $current_dir = getcwd(); chdir($this->tmp_dir); $exts = array('tex', 'aux', 'log', 'dvi', 'png'); foreach ($exts as $ext) { if (file_exists($tmp_filename.'.'.$ext)) { @unlink($tmp_filename.'.'.$ext); } } chdir($current_dir); } /** * Check if the latex code is clean. * * @param string Latex code. * @return bool Is Clean. */ public function isCleanLatex($latex) { foreach ($this->tags_blacklist as $tag) { if (false !== stristr($latex, $tag)) { $this->error_code = 2; $this->error_msg = sprintf(__('The LaTeX tag "%s" is not acceptable.'), $tag); return false; } } return true; } /** * Get the output file based on the latex fragment. * * @param string Latex. * @param bool Is the equation an inline equation (false). * @param string Output file with extension without directory. */ public function getOutputFile($latex, $inline=false) { $inline = ($inline) ? 'inline' : 'normal'; return md5($this->bg_color.'###'.$inline.'###'.$this->resolution.'###'.$latex).'.png'; }} |
