filter/tex/pix.php

   1 <?PHP // $Id$
   2       // This function fetches math. images from the data directory
   3       // If not, it obtains the corresponding TeX expression from the cache_tex db table
   4       // and uses mimeTeX to create the image file
   5
   6     $nomoodlecookie = true;     // Because it interferes with caching
   7
   8     require_once('../../config.php');
   9
  10     if (empty($CFG->textfilters)) {
  11         error ('Filter not enabled!');
  12     } else {
  13         $filters = explode(',', $CFG->textfilters);
  14         if (array_search('filter/tex', $filters) === FALSE) {
  15             error ('Filter not enabled!');
  16         }
  17     }
  18
  19     // disable moodle specific debug messages
  20     disable_debugging();
  21
  22     require_once($CFG->libdir.'/filelib.php');
  23     require_once($CFG->dirroot.'/filter/tex/lib.php');
  24     require_once($CFG->dirroot.'/filter/tex/latex.php');
  25
  26     $cmd    = '';               // Initialise these variables
  27     $status = '';
  28
  29     $relativepath = get_file_argument('pix.php');
  30
  31     $args = explode('/', trim($relativepath, '/'));
  32
  33     if (count($args) == 1) {
  34         $image    = $args[0];
  35         $pathname = $CFG->dataroot.'/filter/tex/'.$image;
  36     } else {
  37         error('No valid arguments supplied');
  38     }
  39
  40     if (!file_exists($pathname)) {
  41         $md5 = str_replace(".{$CFG->filter_tex_convertformat}",'',$image);
  42         if ($texcache = get_record('cache_filters', 'filter', 'tex', 'md5key', $md5)) {
  43             if (!file_exists($CFG->dataroot.'/filter/tex')) {
  44                 make_upload_directory('filter/tex');
  45             }
  46
  47             // try and render with latex first
  48             $latex = new latex();
  49             $density = $CFG->filter_tex_density;
  50             $background = $CFG->filter_tex_latexbackground;
  51             $texexp = html_entity_decode($texcache->rawtext);
  52             $latex_path = $latex->render($texexp, $md5, 12, $density, $background);
  53             if ($latex_path) {
  54                 copy($latex_path, $pathname);
  55                 $latex->clean_up($md5);
  56
  57             } else {
  58                 // failing that, use mimetex
  59                 $texexp = $texcache->rawtext;
  60                 $texexp = str_replace('&lt;', '<', $texexp);
  61                 $texexp = str_replace('&gt;', '>', $texexp);
  62                 $texexp = preg_replace('!\r\n?!', ' ', $texexp);
  63                 $texexp = '\Large '.$texexp;
  64                 $cmd = tex_filter_get_cmd($pathname, $texexp);
  65                 system($cmd, $status);
  66             }
  67         }
  68     }
  69
  70     if (file_exists($pathname)) {
  71         send_file($pathname, $image);
  72     } else {
  73         if (debugging()) {
  74             echo "The shell command<br />$cmd<br />returned status = $status<br />\n";
  75             echo "Image not found!<br />";
  76             echo "Please try the <a href=\"$CFG->wwwroot/filter/tex/texdebug.php\">debugging script</a>";
  77         } else {
  78             echo "Image not found!<br />";
  79             echo "Please try the <a href=\"$CFG->wwwroot/filter/tex/texdebug.php\">debugging script</a><br />";
  80             echo "Please turn on debug mode in site configuration to see more info here.";
  81         }
  82     }
  83 ?>