<?php
// $id: $
/**
 * GD2 toolkit functions
 * With the minimal requirements of PHP 4.3 for Drupal, we use
 * GD2 as the default image processing toolkit.
 */

function gd_toolkit_info() {
  return array('gd' => array('title' => 'Built-in GD2 support for Drupal 6'));
}

/**
 * Retrieve settings for the GD2 toolkit.
 */
function gd_settings() {
  $form = array();
  $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' => '%',
  );

  return $form;
}

/**
 * Scale an image to the specified size using GD.
 */
function gd_resize($source, $destination, $width, $height) {

  // TODO: make some validate function for this in image.inc, we need todo this quite often!
  if (!file_exists($source)) {
    return FALSE;
  }

  // TODO: make some validate function for this in image.inc, we need todo this quite often!
  $info = image_get_info($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($res, TRUE);
  }
  imageCopyResampled($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 gd_rotate($source, $destination, $degrees, $bg_color = 0) {
  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, $bg_color);
  $result = image_gd_close($res, $destination, $info['extension']);

  return $result;
}

/**
 * Crop an image using the GD toolkit.
 */
function 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.
 */
function 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.
 */
function 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);
  }
}