function imageapi_gd_image_rotate in ImageAPI 6

Same name and namespace in other branches

1. 5 imageapi_gd.module \imageapi_gd_image_rotate()

Rotate an image the given number of degrees.

Parameters

$image: An image object. The $image->resource, $image->info['width'], and $image->info['height'] values will be modified by this call.

$degrees: The number of (clockwise) degrees to rotate the image.

$background: An hexadecimal integer specifying the background color to use for the uncovered area of the image after the rotation. E.g. 0x000000 for black, 0xff00ff for magenta, and 0xffffff for white. For images that support transparency, this will default to transparent. Otherwise it will be white.

Return value

TRUE or FALSE, based on success.

File

./imageapi_gd.module, line 155

GD2 toolkit functions

Code

function imageapi_gd_image_rotate(&$image, $degrees, $background) {

  // PHP installations using non-bundled GD do not have imagerotate.
  if (!function_exists('imagerotate')) {
    require_once drupal_get_path('module', 'imageapi_gd') . '/imagerotate.inc';
  }
  $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 pallete 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;
}