pr2/translate/LatexRenderModule.php5

<?php

class LatexRenderModule {

 var $LATEX_PATH = "/usr/bin/latex";
 var $DVIPS_PATH = "/usr/bin/dvips";
 var $CONVERT_PATH = "/usr/bin/convert";

 var $TMP_DIR =
   "/var/tmp/texcache/tmp";
 var $CACHE_DIR =
   "/var/tmp/texcache/cache";

 var $URL_PATH = "/pr2/components/texCache.php5?fileName=";



    function wrap($thunk) {

    $newThunk = <<<EOS
\documentclass[10pt]{article}

        % add additional packages here
        \usepackage{amsmath}
        \usepackage{amsfonts}
        \usepackage{amssymb}
        \usepackage{pst-plot}
        \usepackage{color}

        \pagestyle{empty}
        \begin{document}
        $thunk
        \end{document}
EOS;



      return $newThunk;
    }


 function transform($text) {
    $thunk = $text;
    $hash = md5($thunk);

    $full_name = $this->CACHE_DIR . "/" .
                 $hash . ".png";
    $url = SPath::getRelPath("Common") . $this->URL_PATH . $hash;

    if (!is_file($full_name)) {
      $this->render_latex($thunk, $hash);
      //$this->cleanup($hash);
    }

    $text = "<img src=\"$url\" alt=\"tex\" class=\"latex StdXML3\" >";


  return $text;
 }
 function render_latex($thunk, $hash) {
    //we need to decode html entities that might have special meaning to LaTeX
    $thunk = html_entity_decode($thunk);
    $thunk = $this->wrap($thunk);
      $current_dir = getcwd();
     // $success = chdir($this->TMP_DIR);

      // create temporary LaTeX file
     $fp = fopen($this->TMP_DIR . "/$hash.tex", "w+");
      fwrite($fp, $thunk);
      fclose($fp);

     $dir = dirname(__FILE__);
     $dirString = "sh " . $dir . "/ps2png.sh " . $hash;

      exec($dirString);

      // copy the file to the cache directory
      copy($this->TMP_DIR . "/$hash.png", $this->CACHE_DIR . "/$hash.png");

      chdir($current_dir);
 }

 function cleanup($hash) {
      $current_dir = getcwd();
      chdir($this->TMP_DIR);

      unlink($this->TMP_DIR . "/$hash.tex");
      unlink($this->TMP_DIR . "/$hash.aux");
      unlink($this->TMP_DIR . "/$hash.log");
      unlink($this->TMP_DIR . "/$hash.dvi");
      unlink($this->TMP_DIR . "/$hash.ps");
      unlink($this->TMP_DIR . "/$hash.png");

      chdir($current_dir);
}

}

?>

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