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
7define('NO_DEBUG_DISPLAY', true);
8define('NO_MOODLE_COOKIES', true); // Because it interferes with caching
9
10    require_once('../../config.php');
11
12    if (!filter_is_enabled('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        $convertformat = get_config('filter_tex', 'convertformat');
36        if (strpos($image, '.png')) {
37            $convertformat = 'png';
38        }
39        $md5 = str_replace(".{$convertformat}", '', $image);
40        if ($texcache = $DB->get_record('cache_filters', array('filter'=>'tex', 'md5key'=>$md5))) {
41            if (!file_exists($CFG->dataroot.'/filter/tex')) {
42                make_upload_directory('filter/tex');
43            }
44
45            // try and render with latex first
46            $latex = new latex();
47            $density = get_config('filter_tex', 'density');
48            $background = get_config('filter_tex', 'latexbackground');
49            $texexp = $texcache->rawtext; // the entities are now decoded before inserting to DB
50            $lateximage = $latex->render($texexp, $image, 12, $density, $background);
51            if ($lateximage) {
52                copy($lateximage, $pathname);
53                $latex->clean_up($md5);
54
55            } else {
56                // failing that, use mimetex
57                $texexp = $texcache->rawtext;
58                $texexp = str_replace('&lt;', '<', $texexp);
59                $texexp = str_replace('&gt;', '>', $texexp);
60                $texexp = preg_replace('!\r\n?!', ' ', $texexp);
61                $texexp = '\Large '.$texexp;
62                $cmd = filter_tex_get_cmd($pathname, $texexp);
63                system($cmd, $status);
64            }
65        }
66    }
67
68    if (file_exists($pathname)) {
69        send_file($pathname, $image);
70    } else {
71        if (debugging()) {
72            echo "The shell command<br />$cmd<br />returned status = $status<br />\n";
73            echo "Image not found!<br />";
74            echo "Please try the <a href=\"$CFG->wwwroot/filter/tex/texdebug.php\">debugging script</a>";
75        } else {
76            echo "Image not found!<br />";
77            echo "Please try the <a href=\"$CFG->wwwroot/filter/tex/texdebug.php\">debugging script</a><br />";
78            echo "Please turn on debug mode in site configuration to see more info here.";
79        }
80    }
81