mod/wiki/ewiki/plugins/feature/imgresize_gd.php

   1 <?php
   2
   3 #  if someone uploads an image, which is larger than the allowed
   4 #  image size (EWIKI_IMAGE_MAXSIZE), then this plugin tries to
   5 #  rescale that image until it fits; it utilizes the PHP libgd
   6 #  functions to accomplish this
   7
   8 #  NOTE: It is currently disabled for Win32, because nobody knows, if
   9 #  this will crash the PHP interpreter on those systems.
  10
  11
  12 define("EWIKI_IMGRESIZE_WIN", 0);
  13
  14
  15 if (!strstr(PHP_VERSION, "-dev") && !function_exists("imagecreate") && function_exists("dl")) {   #-- try to load gd lib
  16    @dl("php_gd2.dll") or @dl("gd.so");
  17 }
  18 if (function_exists("imagecreate")) {
  19    $ewiki_plugins["image_resize"][] = "ewiki_binary_resize_image_gd";
  20 }
  21
  22
  23 function ewiki_binary_resize_image_gd(&$filename, &$mime, $return=0) {
  24
  25            /*** this disallows Win32 ***/
  26    if (    (DIRECTORY_SEPARATOR!="/") && !EWIKI_IMAGERESIZE_WIN
  27        || (strpos($mime, "image/")!==0) )
  28    {
  29       return(false);
  30    }
  31
  32    $tmp_rescale = $filename;
  33
  34    #-- initial rescale
  35    $r = EWIKI_IMAGE_MAXSIZE / filesize($tmp_rescale);
  36    $r = ($r) + ($r - 1) * ($r - 1);
  37
  38    #-- read orig image
  39    strtok($mime, "/");
  40    $type = strtok("/");
  41    if (function_exists($pf = "imagecreatefrom$type")) {
  42       $orig_image = $pf($filename);
  43    }
  44    else {
  45       return(false);
  46    }
  47    $orig_x = imagesx($orig_image);
  48    $orig_y = imagesy($orig_image);
  49
  50    #-- change mime from .gif to .png
  51    if (($type == "gif") && (false || function_exists("imagepng") && !function_exists("imagegif"))) {
  52       $type = "png";
  53    }
  54
  55    #-- retry resizing
  56    $loop = 20;
  57    while (($loop--) && (filesize($tmp_rescale) > EWIKI_IMAGE_MAXSIZE)) {
  58
  59       if ($filename == $tmp_rescale) {
  60          $tmp_rescale = tempnam(EWIKI_TMP, "ewiki.img_resize_gd.tmp.");
  61       }
  62
  63       #-- sizes
  64       $new_x = (int) ($orig_x * $r);
  65       $new_y = (int) ($orig_y * $r);
  66
  67       #-- new gd image
  68       $tc = function_exists("imageistruecolor") && imageistruecolor($orig_image);
  69       if (!$tc || ($type == "gif")) {
  70          $new_image = imagecreate($new_x, $new_y);
  71          imagepalettecopy($new_image, $orig_image);
  72       }
  73       else {
  74          $new_image = imagecreatetruecolor($new_x, $new_y);
  75       }
  76
  77       #-- resize action
  78       imagecopyresized($new_image, $orig_image, 0,0, 0,0, $new_x,$new_y, $orig_x,$orig_y);
  79
  80       #-- special things
  81       if ( ($type == "png") && function_exists("imagesavealpha") ) {
  82          imagesavealpha($new_image, 1);
  83       }
  84
  85       #-- save
  86       if (function_exists($pf = "image$type")) {
  87          $pf($new_image, $tmp_rescale);
  88       }
  89       else {
  90          return(false);   # cannot save in orig format (.gif)
  91       }
  92
  93       #-- prepare next run
  94       imagedestroy($new_image);
  95       clearstatcache();
  96       $r *= 0.95;
  97    }
  98
  99    #-- stop
 100    imagedestroy($orig_image);
 101
 102    #-- security check filesizes, abort
 103    if (!filesize($filename) || !filesize($tmp_rescale) || (filesize($tmp_rescale) > EWIKI_IMAGE_MAXSIZE)) {
 104       unlink($tmp_rescale);
 105       return($false);
 106    }
 107
 108    #-- set $mime, as it may have changed (.gif)
 109    $mime = strtok($mime, "/") . "/" . $type;
 110    if (!strstr($filename, ".$type")) {
 111       unlink($filename);
 112       $filename .= ".$type";
 113    }
 114
 115    #-- move tmp file to old name
 116    copy($tmp_rescale, $filename);
 117    unlink($tmp_rescale);
 118    return(true);
 119
 120 }
 121
 122 ?>