lib/gdlib.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * gdlib.php - Collection of routines in Moodle related to
  20  * processing images using GD
  21  *
  22  * @package   core
  23  * @copyright 1999 onwards Martin Dougiamas  {@link http://moodle.com}
  24  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26
  27 defined('MOODLE_INTERNAL') || die();
  28
  29 /**
  30  *
  31  * long description
  32  * @global object
  33  * @param object $dst_img
  34  * @param object $src_img
  35  * @param int $dst_x
  36  * @param int $dst_y
  37  * @param int $src_x
  38  * @param int $src_y
  39  * @param int $dst_w
  40  * @param int $dst_h
  41  * @param int $src_w
  42  * @param int $src_h
  43  * @return bool
  44  * @todo Finish documenting this function
  45  */
  46 function ImageCopyBicubic($dst_img, $src_img, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h) {
  47
  48     global $CFG;
  49
  50     if (function_exists('ImageCopyResampled') and $CFG->gdversion >= 2) {
  51        return ImageCopyResampled($dst_img, $src_img, $dst_x, $dst_y, $src_x, $src_y,
  52                                  $dst_w, $dst_h, $src_w, $src_h);
  53     }
  54
  55     $totalcolors = imagecolorstotal($src_img);
  56     for ($i=0; $i<$totalcolors; $i++) {
  57         if ($colors = ImageColorsForIndex($src_img, $i)) {
  58             ImageColorAllocate($dst_img, $colors['red'], $colors['green'], $colors['blue']);
  59         }
  60     }
  61
  62     $scaleX = ($src_w - 1) / $dst_w;
  63     $scaleY = ($src_h - 1) / $dst_h;
  64
  65     $scaleX2 = $scaleX / 2.0;
  66     $scaleY2 = $scaleY / 2.0;
  67
  68     for ($j = 0; $j < $dst_h; $j++) {
  69         $sY = $j * $scaleY;
  70
  71         for ($i = 0; $i < $dst_w; $i++) {
  72             $sX = $i * $scaleX;
  73
  74             $c1 = ImageColorsForIndex($src_img,ImageColorAt($src_img,(int)$sX,(int)$sY+$scaleY2));
  75             $c2 = ImageColorsForIndex($src_img,ImageColorAt($src_img,(int)$sX,(int)$sY));
  76             $c3 = ImageColorsForIndex($src_img,ImageColorAt($src_img,(int)$sX+$scaleX2,(int)$sY+$scaleY2));
  77             $c4 = ImageColorsForIndex($src_img,ImageColorAt($src_img,(int)$sX+$scaleX2,(int)$sY));
  78
  79             $red = (int) (($c1['red'] + $c2['red'] + $c3['red'] + $c4['red']) / 4);
  80             $green = (int) (($c1['green'] + $c2['green'] + $c3['green'] + $c4['green']) / 4);
  81             $blue = (int) (($c1['blue'] + $c2['blue'] + $c3['blue'] + $c4['blue']) / 4);
  82
  83             $color = ImageColorClosest ($dst_img, $red, $green, $blue);
  84             ImageSetPixel ($dst_img, $i + $dst_x, $j + $dst_y, $color);
  85         }
  86     }
  87 }
  88
  89 /**
  90  * Stores optimised icon images in icon file area
  91  *
  92  * @param $context
  93  * @param component
  94  * @param $itemid
  95  * @param $originalfile
  96  * @return success
  97  */
  98 function process_new_icon($context, $component, $filearea, $itemid, $originalfile) {
  99     global $CFG;
 100
 101     if (empty($CFG->gdversion)) {
 102         return false;
 103     }
 104
 105     if (!is_file($originalfile)) {
 106         return false;
 107     }
 108
 109     $imageinfo = GetImageSize($originalfile);
 110
 111     if (empty($imageinfo)) {
 112         return false;
 113     }
 114
 115     $image = new stdClass();
 116     $image->width  = $imageinfo[0];
 117     $image->height = $imageinfo[1];
 118     $image->type   = $imageinfo[2];
 119
 120     switch ($image->type) {
 121         case IMAGETYPE_GIF:
 122             if (function_exists('ImageCreateFromGIF')) {
 123                 $im = ImageCreateFromGIF($originalfile);
 124             } else {
 125                 debugging('GIF not supported on this server');
 126                 return false;
 127             }
 128             break;
 129         case IMAGETYPE_JPEG:
 130             if (function_exists('ImageCreateFromJPEG')) {
 131                 $im = ImageCreateFromJPEG($originalfile);
 132             } else {
 133                 debugging('JPEG not supported on this server');
 134                 return false;
 135             }
 136             break;
 137         case IMAGETYPE_PNG:
 138             if (function_exists('ImageCreateFromPNG')) {
 139                 $im = ImageCreateFromPNG($originalfile);
 140             } else {
 141                 debugging('PNG not supported on this server');
 142                 return false;
 143             }
 144             break;
 145         default:
 146             return false;
 147     }
 148
 149     if (function_exists('ImagePng')) {
 150         $imagefnc = 'ImagePng';
 151         $imageext = '.png';
 152         $filters = PNG_NO_FILTER;
 153         $quality = 1;
 154     } else if (function_exists('ImageJpeg')) {
 155         $imagefnc = 'ImageJpeg';
 156         $imageext = '.jpg';
 157         $filters = null; // not used
 158         $quality = 90;
 159     } else {
 160         debugging('Jpeg and png not supported on this server, please fix server configuration');
 161         return false;
 162     }
 163
 164     if (function_exists('ImageCreateTrueColor') and $CFG->gdversion >= 2) {
 165         $im1 = ImageCreateTrueColor(100,100);
 166         $im2 = ImageCreateTrueColor(35,35);
 167         if ($image->type == IMAGETYPE_PNG and $imagefnc === 'ImagePng') {
 168             imagealphablending($im1, false);
 169             $color = imagecolorallocatealpha($im1, 0, 0,  0, 127);
 170             imagefill($im1, 0, 0,  $color);
 171             imagesavealpha($im1, true);
 172             imagealphablending($im2, false);
 173             $color = imagecolorallocatealpha($im2, 0, 0,  0, 127);
 174             imagefill($im2, 0, 0,  $color);
 175             imagesavealpha($im2, true);
 176         }
 177     } else {
 178         $im1 = ImageCreate(100,100);
 179         $im2 = ImageCreate(35,35);
 180     }
 181
 182     $cx = $image->width / 2;
 183     $cy = $image->height / 2;
 184
 185     if ($image->width < $image->height) {
 186         $half = floor($image->width / 2.0);
 187     } else {
 188         $half = floor($image->height / 2.0);
 189     }
 190
 191     ImageCopyBicubic($im1, $im, 0, 0, $cx-$half, $cy-$half, 100, 100, $half*2, $half*2);
 192     ImageCopyBicubic($im2, $im, 0, 0, $cx-$half, $cy-$half, 35, 35, $half*2, $half*2);
 193
 194     $fs = get_file_storage();
 195
 196     $icon = array('contextid'=>$context->id, 'component'=>$component, 'filearea'=>$filearea, 'itemid'=>$itemid, 'filepath'=>'/');
 197
 198     ob_start();
 199     if (!$imagefnc($im1, NULL, $quality, $filters)) {
 200         // keep old icons
 201         ob_end_clean();
 202         return false;
 203     }
 204     $data = ob_get_clean();
 205     ImageDestroy($im1);
 206     $icon['filename'] = 'f1'.$imageext;
 207     $fs->delete_area_files($context->id, $component, $filearea, $itemid);
 208     $fs->create_file_from_string($icon, $data);
 209
 210     ob_start();
 211     if (!$imagefnc($im2, NULL, $quality, $filters)) {
 212         ob_end_clean();
 213         $fs->delete_area_files($context->id, $component, $filearea, $itemid);
 214         return false;
 215     }
 216     $data = ob_get_clean();
 217     ImageDestroy($im2);
 218     $icon['filename'] = 'f2'.$imageext;
 219     $fs->create_file_from_string($icon, $data);
 220
 221     return true;
 222 }
 223