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root / drupal7 / modules / system / image.gd.inc @ b0dc3a2e

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<?php
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/**
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 * @file
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 * GD2 toolkit for image manipulation within Drupal.
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 */
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/**
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 * @addtogroup image
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 * @{
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 */
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/**
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 * Retrieve settings for the GD2 toolkit.
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 */
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function image_gd_settings() {
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  if (image_gd_check_settings()) {
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    $form['status'] = array(
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      '#markup' => t('The GD toolkit is installed and working properly.')
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    );
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    $form['image_jpeg_quality'] = array(
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      '#type' => 'textfield',
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      '#title' => t('JPEG quality'),
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      '#description' => t('Define the image quality for JPEG manipulations. Ranges from 0 to 100. Higher values mean better image quality but bigger files.'),
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      '#size' => 10,
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      '#maxlength' => 3,
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      '#default_value' => variable_get('image_jpeg_quality', 75),
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      '#field_suffix' => t('%'),
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    );
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    $form['#element_validate'] = array('image_gd_settings_validate');
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    return $form;
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  }
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  else {
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    form_set_error('image_toolkit', t('The GD image toolkit requires that the GD module for PHP be installed and configured properly. For more information see <a href="@url">PHP\'s image documentation</a>.', array('@url' => 'http://php.net/image')));
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    return FALSE;
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  }
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}
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/**
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 * Validate the submitted GD settings.
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 */
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function image_gd_settings_validate($form, &$form_state) {
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  // Validate image quality range.
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  $value = $form_state['values']['image_jpeg_quality'];
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  if (!is_numeric($value) || $value < 0 || $value > 100) {
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    form_set_error('image_jpeg_quality', t('JPEG quality must be a number between 0 and 100.'));
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  }
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}
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/**
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 * Verify GD2 settings (that the right version is actually installed).
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 *
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 * @return
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 *   A boolean indicating if the GD toolkit is available on this machine.
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 */
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function image_gd_check_settings() {
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  // GD2 support is available.
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  return function_exists('imagegd2');
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}
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/**
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 * Scale an image to the specified size using GD.
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 *
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 * @param $image
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 *   An image object. The $image->resource, $image->info['width'], and
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 *   $image->info['height'] values will be modified by this call.
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 * @param $width
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 *   The new width of the resized image, in pixels.
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 * @param $height
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 *   The new height of the resized image, in pixels.
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 * @return
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 *   TRUE or FALSE, based on success.
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 *
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 * @see image_resize()
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 */
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function image_gd_resize(stdClass $image, $width, $height) {
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  $res = image_gd_create_tmp($image, $width, $height);
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  if (!imagecopyresampled($res, $image->resource, 0, 0, 0, 0, $width, $height, $image->info['width'], $image->info['height'])) {
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    return FALSE;
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  }
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  imagedestroy($image->resource);
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  // Update image object.
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  $image->resource = $res;
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  $image->info['width'] = $width;
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  $image->info['height'] = $height;
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  return TRUE;
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}
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/**
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 * Rotate an image the given number of degrees.
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 *
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 * @param $image
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 *   An image object. The $image->resource, $image->info['width'], and
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 *   $image->info['height'] values will be modified by this call.
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 * @param $degrees
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 *   The number of (clockwise) degrees to rotate the image.
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 * @param $background
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 *   An hexadecimal integer specifying the background color to use for the
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 *   uncovered area of the image after the rotation. E.g. 0x000000 for black,
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 *   0xff00ff for magenta, and 0xffffff for white. For images that support
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 *   transparency, this will default to transparent. Otherwise it will
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 *   be white.
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 * @return
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 *   TRUE or FALSE, based on success.
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 *
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 * @see image_rotate()
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 */
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function image_gd_rotate(stdClass $image, $degrees, $background = NULL) {
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  // PHP installations using non-bundled GD do not have imagerotate.
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  if (!function_exists('imagerotate')) {
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    watchdog('image', 'The image %file could not be rotated because the imagerotate() function is not available in this PHP installation.', array('%file' => $image->source));
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    return FALSE;
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  }
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  // PHP 5.5 GD bug: https://bugs.php.net/bug.php?id=65148: To prevent buggy
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  // behavior on negative multiples of 90 degrees we convert any negative
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  // angle to a positive one between 0 and 360 degrees.
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  $degrees -= floor($degrees / 360) * 360;
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  // Convert the hexadecimal background value to a RGBA array.
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  if (isset($background)) {
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    $background = array(
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      'red' => $background >> 16 & 0xFF,
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      'green' => $background >> 8 & 0xFF,
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      'blue' => $background & 0xFF,
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      'alpha' => 0,
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    );
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  }
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  else {
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    // Background color is not specified: use transparent white as background.
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    $background = array(
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      'red' => 255,
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      'green' => 255,
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      'blue' => 255,
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      'alpha' => 127
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    );
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  }
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  // Store the color index for the background as that is what GD uses.
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  $background_idx = imagecolorallocatealpha($image->resource, $background['red'], $background['green'], $background['blue'], $background['alpha']);
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  // Images are assigned a new color palette when rotating, removing any
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  // transparency flags. For GIF images, keep a record of the transparent color.
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  if ($image->info['extension'] == 'gif') {
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    // GIF does not work with a transparency channel, but can define 1 color
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    // in its palette to act as transparent.
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    // Get the current transparent color, if any.
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    $gif_transparent_id = imagecolortransparent($image->resource);
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    if ($gif_transparent_id !== -1) {
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      // The gif already has a transparent color set: remember it to set it on
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      // the rotated image as well.
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      $transparent_gif_color = imagecolorsforindex($image->resource, $gif_transparent_id);
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      if ($background['alpha'] >= 127) {
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        // We want a transparent background: use the color already set to act
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        // as transparent, as background.
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        $background_idx = $gif_transparent_id;
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      }
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    }
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    else {
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      // The gif does not currently have a transparent color set.
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      if ($background['alpha'] >= 127) {
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        // But as the background is transparent, it should get one.
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        $transparent_gif_color = $background;
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      }
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    }
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  }
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  $image->resource = imagerotate($image->resource, 360 - $degrees, $background_idx);
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  // GIFs need to reassign the transparent color after performing the rotate.
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  if (isset($transparent_gif_color)) {
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    $background = imagecolorexactalpha($image->resource, $transparent_gif_color['red'], $transparent_gif_color['green'], $transparent_gif_color['blue'], $transparent_gif_color['alpha']);
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    imagecolortransparent($image->resource, $background);
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  }
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  $image->info['width'] = imagesx($image->resource);
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  $image->info['height'] = imagesy($image->resource);
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  return TRUE;
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}
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/**
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 * Crop an image using the GD toolkit.
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 *
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 * @param $image
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 *   An image object. The $image->resource, $image->info['width'], and
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 *   $image->info['height'] values will be modified by this call.
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 * @param $x
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 *   The starting x offset at which to start the crop, in pixels.
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 * @param $y
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 *   The starting y offset at which to start the crop, in pixels.
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 * @param $width
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 *   The width of the cropped area, in pixels.
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 * @param $height
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 *   The height of the cropped area, in pixels.
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 * @return
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 *   TRUE or FALSE, based on success.
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 *
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 * @see image_crop()
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 */
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function image_gd_crop(stdClass $image, $x, $y, $width, $height) {
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  $res = image_gd_create_tmp($image, $width, $height);
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  if (!imagecopyresampled($res, $image->resource, 0, 0, $x, $y, $width, $height, $width, $height)) {
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    return FALSE;
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  }
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  // Destroy the original image and return the modified image.
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  imagedestroy($image->resource);
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  $image->resource = $res;
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  $image->info['width'] = $width;
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  $image->info['height'] = $height;
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  return TRUE;
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}
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/**
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 * Convert an image resource to grayscale.
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 *
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 * Note that transparent GIFs loose transparency when desaturated.
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 *
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 * @param $image
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 *   An image object. The $image->resource value will be modified by this call.
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 * @return
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 *   TRUE or FALSE, based on success.
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 *
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 * @see image_desaturate()
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 */
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function image_gd_desaturate(stdClass $image) {
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  // PHP installations using non-bundled GD do not have imagefilter.
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  if (!function_exists('imagefilter')) {
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    watchdog('image', 'The image %file could not be desaturated because the imagefilter() function is not available in this PHP installation.', array('%file' => $image->source));
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    return FALSE;
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  }
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  return imagefilter($image->resource, IMG_FILTER_GRAYSCALE);
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}
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/**
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 * GD helper function to create an image resource from a file.
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 *
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 * @param $image
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 *   An image object. The $image->resource value will populated by this call.
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 * @return
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 *   TRUE or FALSE, based on success.
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 *
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 * @see image_load()
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 */
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function image_gd_load(stdClass $image) {
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  $extension = str_replace('jpg', 'jpeg', $image->info['extension']);
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  $function = 'imagecreatefrom' . $extension;
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  if (function_exists($function) && $image->resource = $function($image->source)) {
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    if (imageistruecolor($image->resource)) {
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      return TRUE;
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    }
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    else {
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      // Convert indexed images to truecolor, copying the image to a new
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      // truecolor resource, so that filters work correctly and don't result
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      // in unnecessary dither.
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      $resource = image_gd_create_tmp($image, $image->info['width'], $image->info['height']);
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      if ($resource) {
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        imagecopy($resource, $image->resource, 0, 0, 0, 0, imagesx($resource), imagesy($resource));
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        imagedestroy($image->resource);
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        $image->resource = $resource;
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      }
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    }
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    return (bool) $image->resource;
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  }
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  return FALSE;
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}
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/**
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 * GD helper to write an image resource to a destination file.
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 *
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 * @param $image
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 *   An image object.
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 * @param $destination
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 *   A string file URI or path where the image should be saved.
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 * @return
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 *   TRUE or FALSE, based on success.
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 *
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 * @see image_save()
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 */
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function image_gd_save(stdClass $image, $destination) {
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  $scheme = file_uri_scheme($destination);
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  // Work around lack of stream wrapper support in imagejpeg() and imagepng().
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  if ($scheme && file_stream_wrapper_valid_scheme($scheme)) {
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    // If destination is not local, save image to temporary local file.
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    $local_wrappers = file_get_stream_wrappers(STREAM_WRAPPERS_LOCAL);
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    if (!isset($local_wrappers[$scheme])) {
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      $permanent_destination = $destination;
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      $destination = drupal_tempnam('temporary://', 'gd_');
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    }
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    // Convert stream wrapper URI to normal path.
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    $destination = drupal_realpath($destination);
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  }
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  $extension = str_replace('jpg', 'jpeg', $image->info['extension']);
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  $function = 'image' . $extension;
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  if (!function_exists($function)) {
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    return FALSE;
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  }
307
  if ($extension == 'jpeg') {
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    $success = $function($image->resource, $destination, variable_get('image_jpeg_quality', 75));
309
  }
310
  else {
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    // Always save PNG images with full transparency.
312
    if ($extension == 'png') {
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      imagealphablending($image->resource, FALSE);
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      imagesavealpha($image->resource, TRUE);
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    }
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    $success = $function($image->resource, $destination);
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  }
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  // Move temporary local file to remote destination.
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  if (isset($permanent_destination) && $success) {
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    return (bool) file_unmanaged_move($destination, $permanent_destination, FILE_EXISTS_REPLACE);
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  }
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  return $success;
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}
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/**
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 * Create a truecolor image preserving transparency from a provided image.
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 *
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 * @param $image
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 *   An image object.
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 * @param $width
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 *   The new width of the new image, in pixels.
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 * @param $height
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 *   The new height of the new image, in pixels.
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 * @return
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 *   A GD image handle.
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 */
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function image_gd_create_tmp(stdClass $image, $width, $height) {
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  $res = imagecreatetruecolor($width, $height);
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340
  if ($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
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        // http://stackoverflow.com/a/3898007).
356
        $transparent_color = imagecolorsforindex($image->resource, $transparent);
357
        $transparent = imagecolorallocate($res, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);
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359
        // Flood with our new transparent color.
360
        imagefill($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
}
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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
 */