filter/tex/pix.php

   1 <?PHP
   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 // disable moodle specific debug messages and any errors in output
   7 define('NO_DEBUG_DISPLAY', true);
   8 define('NO_MOODLE_COOKIES', true); // Because it interferes with caching
   9
  10     require_once('../../config.php');
  11
  12     if (!filter_is_enabled('filter/tex')) {
  13         print_error('filternotenabled');
  14     }
  15
  16     require_once($CFG->libdir.'/filelib.php');
  17     require_once($CFG->dirroot.'/filter/tex/lib.php');
  18     require_once($CFG->dirroot.'/filter/tex/latex.php');
  19
  20     $cmd    = '';               // Initialise these variables
  21     $status = '';
  22
  23     $relativepath = get_file_argument();
  24
  25     $args = explode('/', trim($relativepath, '/'));
  26
  27     if (count($args) == 1) {
  28         $image    = $args[0];
  29         $pathname = $CFG->dataroot.'/filter/tex/'.$image;
  30     } else {
  31         print_error('invalidarguments', 'error');
  32     }
  33
  34     if (!file_exists($pathname)) {
  35         $md5 = str_replace(".{$CFG->filter_tex_convertformat}",'',$image);
  36         if ($texcache = $DB->get_record('cache_filters', array('filter'=>'tex', 'md5key'=>$md5))) {
  37             if (!file_exists($CFG->dataroot.'/filter/tex')) {
  38                 make_upload_directory('filter/tex');
  39             }
  40
  41             // try and render with latex first
  42             $latex = new latex();
  43             $density = $CFG->filter_tex_density;
  44             $background = $CFG->filter_tex_latexbackground;
  45             $texexp = html_entity_decode($texcache->rawtext);
  46             $latex_path = $latex->render($texexp, $md5, 12, $density, $background);
  47             if ($latex_path) {
  48                 copy($latex_path, $pathname);
  49                 $latex->clean_up($md5);
  50
  51             } else {
  52                 // failing that, use mimetex
  53                 $texexp = $texcache->rawtext;
  54                 $texexp = str_replace('&lt;', '<', $texexp);
  55                 $texexp = str_replace('&gt;', '>', $texexp);
  56                 $texexp = preg_replace('!\r\n?!', ' ', $texexp);
  57                 $texexp = '\Large '.$texexp;
  58                 $cmd = filter_tex_get_cmd($pathname, $texexp);
  59                 system($cmd, $status);
  60             }
  61         }
  62     }
  63
  64     if (file_exists($pathname)) {
  65         send_file($pathname, $image);
  66     } else {
  67         if (debugging()) {
  68             echo "The shell command<br />$cmd<br />returned status = $status<br />\n";
  69             echo "Image not found!<br />";
  70             echo "Please try the <a href=\"$CFG->wwwroot/filter/tex/texdebug.php\">debugging script</a>";
  71         } else {
  72             echo "Image not found!<br />";
  73             echo "Please try the <a href=\"$CFG->wwwroot/filter/tex/texdebug.php\">debugging script</a><br />";
  74             echo "Please turn on debug mode in site configuration to see more info here.";
  75         }
  76     }