<?php

// $Id: image.gd.inc,v 1.4 2008/01/15 10:17:42 goba Exp $

/**

 * @file

 * GD2 toolkit for image manipulation within Drupal.

 */

/**

 * @ingroup image

 * @{

 */

/**

 * Retrieve information about the toolkit.

 */

function image_gd_info() {

  return array('name' => 'gd', 'title' => t('GD2 image manipulation toolkit'));

}

/**

 * Retrieve settings for the GD2 toolkit.

 */

function image_gd_settings() {

  if (image_gd_check_settings()) {

    $form = array();

    $form['status'] = array(

      '#value' => t('The GD toolkit is installed and working properly.')

    );

    $form['image_jpeg_quality'] = array(

      '#type' => 'textfield',

      '#title' => t('JPEG quality'),

      '#description' => t('Define the image quality for JPEG manipulations. Ranges from 0 to 100. Higher values mean better image quality but bigger files.'),

      '#size' => 10,

      '#maxlength' => 3,

      '#default_value' => variable_get('image_jpeg_quality', 75),

      '#field_suffix' => t('%'),

    );

    $form['#element_validate'] = array('image_gd_settings_validate');

    return $form;

  }

  else {

    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')));

    return FALSE;

  }

}

/**

 * Validate the submitted GD settings.

 */

function image_gd_settings_validate($form, &$form_state) {

  // Validate image quality range.

  $value = $form_state['values']['image_jpeg_quality'];

  if (!is_numeric($value) || $value < 0 || $value > 100) {

    form_set_error('image_jpeg_quality', t('JPEG quality must be a number between 0 and 100.'));

  }

}

/**

 * Verify GD2 settings (that the right version is actually installed).

 *

 * @return

 *   A boolean indicating if the GD toolkit is avaiable on this machine.

 */

function image_gd_check_settings() {

  if ($check = get_extension_funcs('gd')) {

    if (in_array('imagegd2', $check)) {

      // GD2 support is available.

      return TRUE;

    }

  }

  return FALSE;

}

/**

 * Scale an image to the specified size using GD.

 */

function image_gd_resize($source, $destination, $width, $height) {

  if (!file_exists($source)) {

    return FALSE;

  }

  $info = image_get_info($source);

  if (!$info) {

    return FALSE;

  }

  $im = image_gd_open($source, $info['extension']);

  if (!$im) {

    return FALSE;

  }

  $res = imagecreatetruecolor($width, $height);

  if ($info['extension'] == 'png') {

    $transparency = imagecolorallocatealpha($res, 0, 0, 0, 127);

    imagealphablending($res, FALSE);

    imagefilledrectangle($res, 0, 0, $width, $height, $transparency);

    imagealphablending($res, TRUE);

    imagesavealpha($res, TRUE);

  }

  elseif ($info['extension'] == 'gif') {

    // If we have a specific transparent color.

    $transparency_index = imagecolortransparent($im);

    if ($transparency_index >= 0) {

      // Get the original image's transparent color's RGB values.

      $transparent_color = imagecolorsforindex($im, $transparency_index);

      // Allocate the same color in the new image resource.

      $transparency_index = imagecolorallocate($res, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);

      // Completely fill the background of the new image with allocated color.

      imagefill($res, 0, 0, $transparency_index);

      // Set the background color for new image to transparent.

      imagecolortransparent($res, $transparency_index);

      // Find number of colors in the images palette.

      $number_colors = imagecolorstotal($im);

      // Convert from true color to palette to fix transparency issues.

      imagetruecolortopalette($res, TRUE, $number_colors);

    }

  }

  imagecopyresampled($res, $im, 0, 0, 0, 0, $width, $height, $info['width'], $info['height']);

  $result = image_gd_close($res, $destination, $info['extension']);

  imagedestroy($res);

  imagedestroy($im);

  return $result;

}

/**

 * Rotate an image the given number of degrees.

 */

function image_gd_rotate($source, $destination, $degrees, $background = 0x000000) {

  if (!function_exists('imageRotate')) {

    return FALSE;

  }

  $info = image_get_info($source);

  if (!$info) {

    return FALSE;

  }

  $im = image_gd_open($source, $info['extension']);

  if (!$im) {

    return FALSE;

  }

  $res = imageRotate($im, $degrees, $background);

  $result = image_gd_close($res, $destination, $info['extension']);

  return $result;

}

/**

 * Crop an image using the GD toolkit.

 */

function image_gd_crop($source, $destination, $x, $y, $width, $height) {

  $info = image_get_info($source);

  if (!$info) {

    return FALSE;

  }

  $im = image_gd_open($source, $info['extension']);

  $res = imageCreateTrueColor($width, $height);

  imageCopy($res, $im, 0, 0, $x, $y, $width, $height);

  $result = image_gd_close($res, $destination, $info['extension']);

  imageDestroy($res);

  imageDestroy($im);

  return $result;

}

/**

 * GD helper function to create an image resource from a file.

 *

 * @param $file

 *   A string file path where the iamge should be saved.

 * @param $extension

 *   A string containing one of the following extensions: gif, jpg, jpeg, png.

 * @return

 *   An image resource, or FALSE on error.

 */

function image_gd_open($file, $extension) {

  $extension = str_replace('jpg', 'jpeg', $extension);

  $open_func = 'imageCreateFrom'. $extension;

  if (!function_exists($open_func)) {

    return FALSE;

  }

  return $open_func($file);

}

/**

 * GD helper to write an image resource to a destination file.

 *

 * @param $res

 *   An image resource created with image_gd_open().

 * @param $destination

 *   A string file path where the iamge should be saved.

 * @param $extension

 *   A string containing one of the following extensions: gif, jpg, jpeg, png.

 * @return

 *   Boolean indicating success.

 */

function image_gd_close($res, $destination, $extension) {

  $extension = str_replace('jpg', 'jpeg', $extension);

  $close_func = 'image'. $extension;

  if (!function_exists($close_func)) {

    return FALSE;

  }

  if ($extension == 'jpeg') {

    return $close_func($res, $destination, variable_get('image_jpeg_quality', 75));

  }

  else {

    return $close_func($res, $destination);

  }

}

/**

 * @} End of "ingroup image".

 */