<?php
// $Id: imagecache_canvasactions.module,v 1.3 2008/08/19 14:26:10 dman Exp $

/**
 * @file A collection of canvas (layer) type manipulations for imagecache -
 * including "Watermark"
 *
 * Based on first draft of the code by Dimm (imagecache.module 5--1)
 * http://drupal.org/node/184816
 *
 * Rewritten and ported to Imagecache actions API (imagecache.module 5--2) by
 * dman http://coders.co.nz/
 *
 *
 * Notes about imagecache action extensions. For each action:
 *
 * 1: Impliment imagecache_HOOK_form($formdata) to define the config form.
 *
 * 1a: Impliment theme_imagecache_HOOK_form if needed - optional
 *
 * 2: Impliment imagecache_HOOK_image(&$image, $data) to DO the process
 *
 * 3: Impliment theme_imagecache_HOOK($element) to return a text description of
 * the setting
 *
 * 4: Declare the action in HOOK_imagecache_actions()
 *
 *
 * API ref for hook_image()
 *
 * @param $image array defining an image file, including  :
 *
 *   $image- >source as the filename,
 *
 *   $image->info array
 *
 *   $image->res handle on the image object
 *
 * @param $action array of settings as defined in your form.
 *
 */

// During devel, caching is pointless. Flush it
// imagecache_action_definitions(TRUE);

require_once('utility.inc');

/**
* Implementation of hook_imagecache_actions().
*
* Declare available actions, return help text about this filter.
*
* These funcs are all in their respective include libraries - as configured below
*/
function imagecache_canvasactions_imagecache_actions() {

  $actions = array(
    'canvasactions_definecanvas' => array(
      'name' => t('Define Canvas'),
      'description' => t('Define the size of the working canvas and background color, this controls the dimensions of the output image..'),
      'file' => 'canvasactions.inc',
    ),
    'canvasactions_source2canvas' => array(
      'name' => t('Overlay: source image to canvas'),
      'description' => t('Places the source image onto the canvas for compositing.'),
      'file' => 'canvasactions.inc',
    ),
    'canvasactions_file2canvas' => array(
      'name' => t('Overlay: file image to canvas (watermark)'),
      'description' => t(' Choose the file image you wish to use as an overlay, and position it in a layer on top of the canvas.'),
      'file' => 'canvasactions.inc',
    ),
    'canvasactions_canvas2file' => array(
      'name' => t('Underlay: place a file image under the current image (background)'),
      'description' => t(' Choose the file image you wish to use as an background, and position the processed image on it.'),
      'file' => 'canvasactions.inc',
    ),
  );

  return $actions;
}





/**
 * Need to flush the cache when this module is enabled
 */
function imagecache_canvasactions_install() {
  imagecache_action_definitions(TRUE);
  cache_clear_all('imagecache_actions', 'cache');
  drupal_set_message(t('Additional imagecache actions should now be available in the presets !settings_link', array('!settings_link' => l(t('settings'), 'admin/build/imagecache'))));
}


//////////////////////
// imageapi extensions
// Maybe shift into there one day

/**
 * Place one image over another
 *
 * @param $overlay may be a filename or an imageAPI object
 * @return bool success
 * @ingroup imageapi
 */
function imageapi_image_overlay(&$image, $overlay, $x, $y, $alpha) {
  return call_user_func_array($image->toolkit .'_image_overlay', array(&$image, $overlay, $x, $y, $alpha));
}

/**
 * Place one image over another
 * This modifies the passed image by reference
 *
 * @ingroup imageapi
 * @param $overlay may be a filename or an imageAPI object
 * @param alpha from 0-100.
 * @return bool success
 */
function imageapi_gd_image_overlay(&$image, $overlay, $x, $y, $alpha) {
  if (is_string($overlay) ) {
    if (! file_exists($overlay)) {
      watchdog('imagecache', 'Image file does not exist. Attempted to overlay $overlay');
    }
    $overlay = imageapi_image_open($overlay);
  }

  $x_ins = _imagecache_keyword_filter($x, $image->info['width'], $overlay->info['width']);
  $y_ins = _imagecache_keyword_filter($y, $image->info['height'], $overlay->info['height']);

  // imagecopymerge doesn't do alpha transparency right?
  //imagealphablending($image->res, false);
  //imagesavealpha($image->res, TRUE);
  //imagealphablending($overlay->res, false);
  //imagesavealpha($overlay->res, TRUE);
  // imagecopymerge($image->res, $overlay->res, $x_ins, $y_ins, 0, 0, $overlay->info['width'], $overlay->info['height'], $alpha);
  // Silly thing, it's easy. Use the attached library below instead

  require_once('watermark.inc');
  $watermark = new watermark();
  $image->res = $watermark->create_watermark($image->res, $overlay->res, $x_ins, $y_ins, $alpha);

  imagedestroy($overlay->res);
  return TRUE;
}