crm.fsf.org/20131203/files/modules/system/image.gd.inc

   1 <?php
   2
   3 /**
   4  * @file
   5  * GD2 toolkit for image manipulation within Drupal.
   6  */
   7
   8 /**
   9  * @addtogroup image
  10  * @{
  11  */
  12
  13 /**
  14  * Retrieve settings for the GD2 toolkit.
  15  */
  16 function image_gd_settings() {
  17   if (image_gd_check_settings()) {
  18     $form['status'] = array(
  19       '#markup' => t('The GD toolkit is installed and working properly.')
  20     );
  21
  22     $form['image_jpeg_quality'] = array(
  23       '#type' => 'textfield',
  24       '#title' => t('JPEG quality'),
  25       '#description' => t('Define the image quality for JPEG manipulations. Ranges from 0 to 100. Higher values mean better image quality but bigger files.'),
  26       '#size' => 10,
  27       '#maxlength' => 3,
  28       '#default_value' => variable_get('image_jpeg_quality', 75),
  29       '#field_suffix' => t('%'),
  30     );
  31     $form['#element_validate'] = array('image_gd_settings_validate');
  32
  33     return $form;
  34   }
  35   else {
  36     form_set_error('image_toolkit', t('The GD image toolkit requires that the GD module for PHP be installed and configured properly. For more information see <a href="@url">PHP\'s image documentation</a>.', array('@url' => 'http://php.net/image')));
  37     return FALSE;
  38   }
  39 }
  40
  41 /**
  42  * Validate the submitted GD settings.
  43  */
  44 function image_gd_settings_validate($form, &$form_state) {
  45   // Validate image quality range.
  46   $value = $form_state['values']['image_jpeg_quality'];
  47   if (!is_numeric($value) || $value < 0 || $value > 100) {
  48     form_set_error('image_jpeg_quality', t('JPEG quality must be a number between 0 and 100.'));
  49   }
  50 }
  51
  52 /**
  53  * Verify GD2 settings (that the right version is actually installed).
  54  *
  55  * @return
  56  *   A boolean indicating if the GD toolkit is available on this machine.
  57  */
  58 function image_gd_check_settings() {
  59   // GD2 support is available.
  60   return function_exists('imagegd2');
  61 }
  62
  63 /**
  64  * Scale an image to the specified size using GD.
  65  *
  66  * @param $image
  67  *   An image object. The $image->resource, $image->info['width'], and
  68  *   $image->info['height'] values will be modified by this call.
  69  * @param $width
  70  *   The new width of the resized image, in pixels.
  71  * @param $height
  72  *   The new height of the resized image, in pixels.
  73  * @return
  74  *   TRUE or FALSE, based on success.
  75  *
  76  * @see image_resize()
  77  */
  78 function image_gd_resize(stdClass $image, $width, $height) {
  79   $res = image_gd_create_tmp($image, $width, $height);
  80
  81   if (!imagecopyresampled($res, $image->resource, 0, 0, 0, 0, $width, $height, $image->info['width'], $image->info['height'])) {
  82     return FALSE;
  83   }
  84
  85   imagedestroy($image->resource);
  86   // Update image object.
  87   $image->resource = $res;
  88   $image->info['width'] = $width;
  89   $image->info['height'] = $height;
  90   return TRUE;
  91 }
  92
  93 /**
  94  * Rotate an image the given number of degrees.
  95  *
  96  * @param $image
  97  *   An image object. The $image->resource, $image->info['width'], and
  98  *   $image->info['height'] values will be modified by this call.
  99  * @param $degrees
 100  *   The number of (clockwise) degrees to rotate the image.
 101  * @param $background
 102  *   An hexadecimal integer specifying the background color to use for the
 103  *   uncovered area of the image after the rotation. E.g. 0x000000 for black,
 104  *   0xff00ff for magenta, and 0xffffff for white. For images that support
 105  *   transparency, this will default to transparent. Otherwise it will
 106  *   be white.
 107  * @return
 108  *   TRUE or FALSE, based on success.
 109  *
 110  * @see image_rotate()
 111  */
 112 function image_gd_rotate(stdClass $image, $degrees, $background = NULL) {
 113   // PHP installations using non-bundled GD do not have imagerotate.
 114   if (!function_exists('imagerotate')) {
 115     watchdog('image', 'The image %file could not be rotated because the imagerotate() function is not available in this PHP installation.', array('%file' => $image->source));
 116     return FALSE;
 117   }
 118
 119   // PHP 5.5 GD bug: https://bugs.php.net/bug.php?id=65148: To prevent buggy
 120   // behavior on negative multiples of 90 degrees we convert any negative
 121   // angle to a positive one between 0 and 360 degrees.
 122   $degrees -= floor($degrees / 360) * 360;
 123
 124   // Convert the hexadecimal background value to a RGBA array.
 125   if (isset($background)) {
 126     $background = array(
 127       'red' => $background >> 16 & 0xFF,
 128       'green' => $background >> 8 & 0xFF,
 129       'blue' => $background & 0xFF,
 130       'alpha' => 0,
 131     );
 132   }
 133   else {
 134     // Background color is not specified: use transparent white as background.
 135     $background = array(
 136       'red' => 255,
 137       'green' => 255,
 138       'blue' => 255,
 139       'alpha' => 127
 140     );
 141   }
 142
 143   // Store the color index for the background as that is what GD uses.
 144   $background_idx = imagecolorallocatealpha($image->resource, $background['red'], $background['green'], $background['blue'], $background['alpha']);
 145
 146   // Images are assigned a new color palette when rotating, removing any
 147   // transparency flags. For GIF images, keep a record of the transparent color.
 148   if ($image->info['extension'] == 'gif') {
 149     // GIF does not work with a transparency channel, but can define 1 color
 150     // in its palette to act as transparent.
 151
 152     // Get the current transparent color, if any.
 153     $gif_transparent_id = imagecolortransparent($image->resource);
 154     if ($gif_transparent_id !== -1) {
 155       // The gif already has a transparent color set: remember it to set it on
 156       // the rotated image as well.
 157       $transparent_gif_color = imagecolorsforindex($image->resource, $gif_transparent_id);
 158
 159       if ($background['alpha'] >= 127) {
 160         // We want a transparent background: use the color already set to act
 161         // as transparent, as background.
 162         $background_idx = $gif_transparent_id;
 163       }
 164     }
 165     else {
 166       // The gif does not currently have a transparent color set.
 167       if ($background['alpha'] >= 127) {
 168         // But as the background is transparent, it should get one.
 169         $transparent_gif_color = $background;
 170       }
 171     }
 172   }
 173
 174   $image->resource = imagerotate($image->resource, 360 - $degrees, $background_idx);
 175
 176   // GIFs need to reassign the transparent color after performing the rotate.
 177   if (isset($transparent_gif_color)) {
 178     $background = imagecolorexactalpha($image->resource, $transparent_gif_color['red'], $transparent_gif_color['green'], $transparent_gif_color['blue'], $transparent_gif_color['alpha']);
 179     imagecolortransparent($image->resource, $background);
 180   }
 181
 182   $image->info['width'] = imagesx($image->resource);
 183   $image->info['height'] = imagesy($image->resource);
 184   return TRUE;
 185 }
 186
 187 /**
 188  * Crop an image using the GD toolkit.
 189  *
 190  * @param $image
 191  *   An image object. The $image->resource, $image->info['width'], and
 192  *   $image->info['height'] values will be modified by this call.
 193  * @param $x
 194  *   The starting x offset at which to start the crop, in pixels.
 195  * @param $y
 196  *   The starting y offset at which to start the crop, in pixels.
 197  * @param $width
 198  *   The width of the cropped area, in pixels.
 199  * @param $height
 200  *   The height of the cropped area, in pixels.
 201  * @return
 202  *   TRUE or FALSE, based on success.
 203  *
 204  * @see image_crop()
 205  */
 206 function image_gd_crop(stdClass $image, $x, $y, $width, $height) {
 207   $res = image_gd_create_tmp($image, $width, $height);
 208
 209   if (!imagecopyresampled($res, $image->resource, 0, 0, $x, $y, $width, $height, $width, $height)) {
 210     return FALSE;
 211   }
 212
 213   // Destroy the original image and return the modified image.
 214   imagedestroy($image->resource);
 215   $image->resource = $res;
 216   $image->info['width'] = $width;
 217   $image->info['height'] = $height;
 218   return TRUE;
 219 }
 220
 221 /**
 222  * Convert an image resource to grayscale.
 223  *
 224  * Note that transparent GIFs loose transparency when desaturated.
 225  *
 226  * @param $image
 227  *   An image object. The $image->resource value will be modified by this call.
 228  * @return
 229  *   TRUE or FALSE, based on success.
 230  *
 231  * @see image_desaturate()
 232  */
 233 function image_gd_desaturate(stdClass $image) {
 234   // PHP installations using non-bundled GD do not have imagefilter.
 235   if (!function_exists('imagefilter')) {
 236     watchdog('image', 'The image %file could not be desaturated because the imagefilter() function is not available in this PHP installation.', array('%file' => $image->source));
 237     return FALSE;
 238   }
 239
 240   return imagefilter($image->resource, IMG_FILTER_GRAYSCALE);
 241 }
 242
 243 /**
 244  * GD helper function to create an image resource from a file.
 245  *
 246  * @param $image
 247  *   An image object. The $image->resource value will populated by this call.
 248  * @return
 249  *   TRUE or FALSE, based on success.
 250  *
 251  * @see image_load()
 252  */
 253 function image_gd_load(stdClass $image) {
 254   $extension = str_replace('jpg', 'jpeg', $image->info['extension']);
 255   $function = 'imagecreatefrom' . $extension;
 256   if (function_exists($function) && $image->resource = $function($image->source)) {
 257     if (imageistruecolor($image->resource)) {
 258       return TRUE;
 259     }
 260     else {
 261       // Convert indexed images to truecolor, copying the image to a new
 262       // truecolor resource, so that filters work correctly and don't result
 263       // in unnecessary dither.
 264       $resource = image_gd_create_tmp($image, $image->info['width'], $image->info['height']);
 265       if ($resource) {
 266         imagecopy($resource, $image->resource, 0, 0, 0, 0, imagesx($resource), imagesy($resource));
 267         imagedestroy($image->resource);
 268         $image->resource = $resource;
 269       }
 270     }
 271     return (bool) $image->resource;
 272   }
 273   return FALSE;
 274 }
 275
 276 /**
 277  * GD helper to write an image resource to a destination file.
 278  *
 279  * @param $image
 280  *   An image object.
 281  * @param $destination
 282  *   A string file URI or path where the image should be saved.
 283  * @return
 284  *   TRUE or FALSE, based on success.
 285  *
 286  * @see image_save()
 287  */
 288 function image_gd_save(stdClass $image, $destination) {
 289   $scheme = file_uri_scheme($destination);
 290   // Work around lack of stream wrapper support in imagejpeg() and imagepng().
 291   if ($scheme && file_stream_wrapper_valid_scheme($scheme)) {
 292     // If destination is not local, save image to temporary local file.
 293     $local_wrappers = file_get_stream_wrappers(STREAM_WRAPPERS_LOCAL);
 294     if (!isset($local_wrappers[$scheme])) {
 295       $permanent_destination = $destination;
 296       $destination = drupal_tempnam('temporary://', 'gd_');
 297     }
 298     // Convert stream wrapper URI to normal path.
 299     $destination = drupal_realpath($destination);
 300   }
 301
 302   $extension = str_replace('jpg', 'jpeg', $image->info['extension']);
 303   $function = 'image' . $extension;
 304   if (!function_exists($function)) {
 305     return FALSE;
 306   }
 307   if ($extension == 'jpeg') {
 308     $success = $function($image->resource, $destination, variable_get('image_jpeg_quality', 75));
 309   }
 310   else {
 311     // Always save PNG images with full transparency.
 312     if ($extension == 'png') {
 313       imagealphablending($image->resource, FALSE);
 314       imagesavealpha($image->resource, TRUE);
 315     }
 316     $success = $function($image->resource, $destination);
 317   }
 318   // Move temporary local file to remote destination.
 319   if (isset($permanent_destination) && $success) {
 320     return (bool) file_unmanaged_move($destination, $permanent_destination, FILE_EXISTS_REPLACE);
 321   }
 322   return $success;
 323 }
 324
 325 /**
 326  * Create a truecolor image preserving transparency from a provided image.
 327  *
 328  * @param $image
 329  *   An image object.
 330  * @param $width
 331  *   The new width of the new image, in pixels.
 332  * @param $height
 333  *   The new height of the new image, in pixels.
 334  * @return
 335  *   A GD image handle.
 336  */
 337 function image_gd_create_tmp(stdClass $image, $width, $height) {
 338   $res = imagecreatetruecolor($width, $height);
 339
 340   if ($image->info['extension'] == 'gif') {
 341     // Find out if a transparent color is set, will return -1 if no
 342     // transparent color has been defined in the image.
 343     $transparent = imagecolortransparent($image->resource);
 344
 345     if ($transparent >= 0) {
 346       // Find out the number of colors in the image palette. It will be 0 for
 347       // truecolor images.
 348       $palette_size = imagecolorstotal($image->resource);
 349       if ($palette_size == 0 || $transparent < $palette_size) {
 350         // Set the transparent color in the new resource, either if it is a
 351         // truecolor image or if the transparent color is part of the palette.
 352         // Since the index of the transparency color is a property of the
 353         // image rather than of the palette, it is possible that an image
 354         // could be created with this index set outside the palette size (see
 355         // http://stackoverflow.com/a/3898007).
 356         $transparent_color = imagecolorsforindex($image->resource, $transparent);
 357         $transparent = imagecolorallocate($res, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);
 358
 359         // Flood with our new transparent color.
 360         imagefill($res, 0, 0, $transparent);
 361         imagecolortransparent($res, $transparent);
 362       }
 363       else {
 364         imagefill($res, 0, 0, imagecolorallocate($res, 255, 255, 255));
 365       }
 366     }
 367   }
 368   elseif ($image->info['extension'] == 'png') {
 369     imagealphablending($res, FALSE);
 370     $transparency = imagecolorallocatealpha($res, 0, 0, 0, 127);
 371     imagefill($res, 0, 0, $transparency);
 372     imagealphablending($res, TRUE);
 373     imagesavealpha($res, TRUE);
 374   }
 375   else {
 376     imagefill($res, 0, 0, imagecolorallocate($res, 255, 255, 255));
 377   }
 378
 379   return $res;
 380 }
 381
 382 /**
 383  * Get details about an image.
 384  *
 385  * @param $image
 386  *   An image object.
 387  * @return
 388  *   FALSE, if the file could not be found or is not an image. Otherwise, a
 389  *   keyed array containing information about the image:
 390  *   - "width": Width, in pixels.
 391  *   - "height": Height, in pixels.
 392  *   - "extension": Commonly used file extension for the image.
 393  *   - "mime_type": MIME type ('image/jpeg', 'image/gif', 'image/png').
 394  *
 395  * @see image_get_info()
 396  */
 397 function image_gd_get_info(stdClass $image) {
 398   $details = FALSE;
 399   $data = @getimagesize($image->source);
 400
 401   if (isset($data) && is_array($data)) {
 402     $extensions = array('1' => 'gif', '2' => 'jpg', '3' => 'png');
 403     $extension = isset($extensions[$data[2]]) ?  $extensions[$data[2]] : '';
 404     $details = array(
 405       'width'     => $data[0],
 406       'height'    => $data[1],
 407       'extension' => $extension,
 408       'mime_type' => $data['mime'],
 409     );
 410   }
 411
 412   return $details;
 413 }
 414
 415 /**
 416  * @} End of "addtogroup image".
 417  */