public function GDToolkit::rotate

Implements \Drupal\system\Plugin\ImageToolkitInterface::rotate().

Overrides ImageToolkitInterface::rotate

File

drupal/core/modules/system/lib/Drupal/system/Plugin/ImageToolkit/GDToolkit.php, line 71

Contains \Drupal\system\Plugin\ImageToolkit\GDToolkit;.

Class

GDToolkit

Defines the GD2 toolkit for image manipulation within Drupal.

Namespace

Code

public function rotate($image, $degrees, $background = NULL) {

  // PHP installations using non-bundled GD do not have imagerotate.
  if (!function_exists('imagerotate')) {
    watchdog('image', 'The image %file could not be rotated because the imagerotate() function is not available in this PHP installation.', array(
      '%file' => $image->source,
    ));
    return FALSE;
  }
  $width = $image->info['width'];
  $height = $image->info['height'];

  // Convert the hexadecimal background value to a color index value.
  if (isset($background)) {
    $rgb = array();
    for ($i = 16; $i >= 0; $i -= 8) {
      $rgb[] = $background >> $i & 0xff;
    }
    $background = imagecolorallocatealpha($image->resource, $rgb[0], $rgb[1], $rgb[2], 0);
  }
  else {

    // Get the current transparent color.
    $background = imagecolortransparent($image->resource);

    // If no transparent colors, use white.
    if ($background == 0) {
      $background = imagecolorallocatealpha($image->resource, 255, 255, 255, 0);
    }
  }

  // Images are assigned a new color palette when rotating, removing any
  // transparency flags. For GIF images, keep a record of the transparent color.
  if ($image->info['extension'] == 'gif') {
    $transparent_index = imagecolortransparent($image->resource);
    if ($transparent_index != 0) {
      $transparent_gif_color = imagecolorsforindex($image->resource, $transparent_index);
    }
  }
  $image->resource = imagerotate($image->resource, 360 - $degrees, $background);

  // GIFs need to reassign the transparent color after performing the rotate.
  if (isset($transparent_gif_color)) {
    $background = imagecolorexactalpha($image->resource, $transparent_gif_color['red'], $transparent_gif_color['green'], $transparent_gif_color['blue'], $transparent_gif_color['alpha']);
    imagecolortransparent($image->resource, $background);
  }
  $image->info['width'] = imagesx($image->resource);
  $image->info['height'] = imagesy($image->resource);
  return TRUE;
}