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('defaultsettings.php' );
  24     require_once('latex.php');
  25
  26     $CFG->texfilterdir = 'filter/tex';
  27     $CFG->teximagedir  = 'filter/tex';
  28
  29     // check/initialise default configuration for filter (in defaultsettings.php)
  30     tex_defaultsettings();
  31
  32     $cmd    = '';               // Initialise these variables
  33     $status = '';
  34
  35     error_reporting(E_ALL);
  36
  37     $relativepath = get_file_argument('pix.php');
  38
  39     $args = explode('/', trim($relativepath, '/'));
  40
  41     if (count($args) == 1) {
  42         $image    = $args[0];
  43         $pathname = $CFG->dataroot.'/'.$CFG->teximagedir.'/'.$image;
  44     } else {
  45         error('No valid arguments supplied');
  46     }
  47
  48     if (!file_exists($pathname)) {
  49         $md5 = str_replace('.gif','',$image);
  50         if ($texcache = get_record('cache_filters', 'filter', 'tex', 'md5key', $md5)) {
  51             if (!file_exists($CFG->dataroot.'/'.$CFG->teximagedir)) {
  52                 make_upload_directory($CFG->teximagedir);
  53             }
  54
  55             // try and render with latex first
  56             $latex = new latex();
  57             $density = $CFG->filter_tex_density;
  58             $background = $CFG->filter_tex_latexbackground;
  59             $texexp = html_entity_decode( $texcache->rawtext );
  60             $latex_path = $latex->render( $texexp, $md5, 12, $density, $background );
  61             if ($latex_path) {
  62                 copy( $latex_path, $pathname );
  63                 $latex->clean_up( $md5 );
  64             }
  65             else {
  66                 // failing that, use mimetex
  67                 $texexp = $texcache->rawtext;
  68                 $texexp = str_replace('&lt;','<',$texexp);
  69                 $texexp = str_replace('&gt;','>',$texexp);
  70                 $texexp = preg_replace('!\r\n?!',' ',$texexp);
  71                 $texexp = '\Large ' . $texexp;
  72                 $texexp = escapeshellarg($texexp);
  73
  74                 if ((PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows")) {
  75                     $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex.exe";
  76                     $cmd = str_replace(' ','^ ',$cmd);
  77                     $cmd .= " ++ -e  \"$pathname\" -- $texexp";
  78                 } else if (is_executable("$CFG->dirroot/$CFG->texfilterdir/mimetex")) {   /// Use the custom binary
  79
  80                     $cmd = "$CFG->dirroot/$CFG->texfilterdir/mimetex -e $pathname -- $texexp";
  81
  82                 } else {                                                           /// Auto-detect the right TeX binary
  83                     switch (PHP_OS) {
  84
  85                         case "Linux":
  86                             $cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.linux\" -e \"$pathname\" -- $texexp";
  87                         break;
  88
  89                         case "Darwin":
  90                             $cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.darwin\" -e \"$pathname\" -- $texexp";
  91                         break;
  92
  93                         case "FreeBSD":
  94                             $cmd = "\"$CFG->dirroot/$CFG->texfilterdir/mimetex.freebsd\" -e \"$pathname\" $texexp";
  95                         break;
  96
  97                         default:      /// Nothing was found, so tell them how to fix it.
  98                             if (debugging()) {
  99                                 echo "Make sure you have an appropriate MimeTeX binary here:\n\n";
 100                                 echo "    $CFG->dirroot/$CFG->texfilterdir/mimetex\n\n";
 101                                 echo "and that it has the right permissions set on it as executable program.\n\n";
 102                                 echo "You can get the latest binaries for your ".PHP_OS." platform from: \n\n";
 103                                 echo "    http://moodle.org/download/mimetex/";
 104                             } else {
 105                                 echo "Mimetex executable was not found,\n";
 106                                 echo "Please turn on debug mode in site configuration to see more info here.";
 107                             }
 108                              die;
 109                         break;
 110                     }
 111                 }
 112                 system($cmd, $status);
 113             }
 114         }
 115     }
 116
 117     if (file_exists($pathname)) {
 118         send_file($pathname, $image);
 119     } else {
 120         if (debugging()) {
 121             echo "The shell command<br />$cmd<br />returned status = $status<br />\n";
 122             echo "Image not found!<br />";
 123             echo "Please try the <a href=\"$CFG->wwwroot/$CFG->texfilterdir/texdebug.php\">debugging script</a>";
 124         } else {
 125             echo "Image not found!<br />";
 126             echo "Please try the <a href=\"$CFG->wwwroot/$CFG->texfilterdir/texdebug.php\">debugging script</a><br />";
 127             echo "Please turn on debug mode in site configuration to see more info here.";
 128         }
 129     }
 130 ?>