<?php
// $Id: imagecache_coloractions.module,v 1.4.2.9 2009/05/02 04:54:50 dman Exp $

/**
 * @file
 * Additional actions for imagecache processing.
 *
 * Exposes some of the simpler PHP 'imagefilter' actions (colorshift,
 * brightness, negative)
 * -  A transparency masker for merging with backgrounds.
 * -  A pseudo - file conversion feature.
 *
 * Compatible with the 2008 revision (imagecache 2)
 *
 * @author dan http://coders.co.nz
 */

// During devel, caching is pointless. Flush it
//imagecache_action_definitions(TRUE);

require_once(dirname(__FILE__) .'/utility.inc');

/**
 * Implementation of hook_imagecache_actions().
 *
 * Declare available actions, return help text about this filter.
 */
function imagecache_coloractions_imagecache_actions() {

  $actions = array(
    'imagecache_colorshift' => array(
      'name' => 'Color Shift',
      'description' => 'Adjust image colors.',
    ),
    'imagecache_brightness' => array(
      'name' => 'Brightness',
      'description' => 'Adjust image brightness.',
    ),
    'imagecache_inverse' => array(
      'name' => t('Negative Image'),
      'description' => t('Invert colors and brightness.')
    ),
    'imagecache_convert' => array(
      'name' => t('Change File format'),
      'description' => t('Choose to save the image as a different filetype.')
    ),
    'imagecache_alpha' => array(
      'name' => t('Alpha Transparency'),
      'description' => t('Adjust transparency.'),
      'file' => 'transparency.inc',
    ),
  );
  return $actions;
}

function imagecache_coloractions_theme() {
  return array(
    'imagecache_colorshift' => array(
      'arguments' => array('element' => NULL),
    ),
    'imagecache_alpha' => array(
      'arguments' => array('element' => NULL),
    ),
    'imagecache_brightness' => array(
      'arguments' => array('element' => NULL),
    ),
    'imagecache_convert' => array(
      'arguments' => array('element' => NULL),
    ),
  );
}

/**
 * Implementation of imagecache_hook_form()
 *
 * Settings for colorshift actions.
 *
 * @param $action array of settings for this action
 * @return a form definition
 */
function imagecache_colorshift_form($action) {
  $defaults = array(
    'RGB' => array(
      'HEX' => '#FF0000',
    ),
  );
  $action = array_merge($defaults, (array)$action);
  $form = array('#theme' => 'imagecache_rgb_form');
  $form['RGB'] = imagecache_rgb_form($action['RGB']);
  $form['note'] = array('#value' => t("<p>
    Note that colorshift is a mathematical filter that doesn't always 
    have the expected result. 
    To shift an image precisely TO a target color, 
    desaturate (greyscale) it before colorizing.
    The hue (color wheel) is the <em>direction</em> the 
    existing colors are shifted. The tone (inner box) is the amount.
    Keep the tone half-way up the left site of the color box 
    for best results.
  </p>"));
  return $form;
}


/**
 * Implementation of theme_hook() for imagecache_ui.module
 */
function theme_imagecache_colorshift($element) {
  $action = $element['#value'];
  return theme_imagecacheactions_rgb($action['RGB']);
}


/**
 * Implementation of hook_image()
 *
 * Process the imagecache action on the passed image
 *
 * Just converts and passes the vals to the all-purpose 'filter' action
 */
function imagecache_colorshift_image(&$image, $data = array()) {
  // convert color from hex (as it is stored in the UI)
  if($data['RGB']['HEX'] && $deduced = hex_to_rgb($data['RGB']['HEX'])) {
    $data['RGB'] = array_merge($data['RGB'], $deduced);
  }

  $data['filter'] = 4;
  $data['filter_arg1'] = $data['RGB']['red'];
  $data['filter_arg2'] = $data['RGB']['green'];
  $data['filter_arg3'] = $data['RGB']['blue'];
  return imagecache_imagefilter($image, $data);
}

/**
 * Implementation of imagecache_hook_form()
 *
 * Settings for colorshift actions.
 *
 * @param $action array of settings for this action
 * @return a form definition
 */
function imagecache_brightness_form($action) {
  $default = array('filter_arg1' => '100',);
  $action = array_merge($default, (array)$action);  
  $form = array();
  $form['help'] = array( '#value' => t("The brightness effect seldom looks good on its own, but can be useful to wash out an image before making it transparent - eg for a watermark.") );
  $form['filter_arg1'] = array(
    '#type' => 'textfield',
    '#title' => t('Brightness'),
    '#description' => t('-255 - +255'),
    '#default_value' => $action['filter_arg1'],
    '#size' => 3
  );
  return $form;
}

/**
 * Implementation of hook_image()
 *
 * Process the imagecache action on the passed image
 */
function imagecache_brightness_image(&$image, $data = array()) {
  $data['filter'] = 2;
  return imagecache_imagefilter($image, $data);
}

/**
 * Implementation of theme_hook() for imagecache_ui.module
 */
function theme_imagecache_brightness($element) {
  return t("Adjust") ." : ". $element['#value']['filter_arg1'];
}


/**
 * Implementation of imagecache_hook_form()
 *
 * No settings.
 *
 * @param $action array of settings for this action
 * @return a form definition
 */
function imagecache_inverse_form($action) {
  $form = array();
  return $form;
}

/**
 * Implementation of hook_image()
 *
 * Process the imagecache action on the passed image
 */
function imagecache_inverse_image(&$image, $data = array()) {
  $data['filter'] = 0;
  return imagecache_imagefilter($image, $data);
}


/**
 * Stub for the image toolkit.
 *
 * Used by brightness and colorize
 *
 * TODO: other toolkits unimplimented yet.
 * Just forward the job to gdtoolkit for
 * now
 *
 * @param $image handle on the image definition, including a gd image resource
 * to act upon
 * @param $data settings for this process.
 * @return bool success
 */
function imagecache_imagefilter($image, $data) {
  if ($image->toolkit != 'imageapi_gd') {
    drupal_set_message("Imagefilter is only currently supported for GD toolkit. Code welcome.", 'error');
    return FALSE;
  }
  if (! imagecache_gd_imagefilter($image, $data['filter'], $data['filter_arg1'], isset($data['filter_arg2']) ? $data['filter_arg2'] : NULL, isset($data['filter_arg3']) ? $data['filter_arg3'] : NULL)) {
    watchdog('imagecache', 'imagecache_imagefilter failed. image: %image, data: %data.', array('%path' => $image, '%data' => print_r($data, TRUE)), WATCHDOG_ERROR);
    return FALSE;
  }
  return TRUE;
}

/**
 * Attempt to run imagefilter, which may or may not be included with your
 * gdtoolkit. If it isn't, a local script is used to emulate the simpler of its
 * functions.
 */
function imagecache_gd_imagefilter($image, $filter, $arg1, $arg2, $arg3) {
  // some distros that allegedly include PHP5 GD2 are faulty.
  // thankyou http://www.weberdev.com/get_example-4601.html
  if (!function_exists('imagefilter')) {
    include_once('imagefilter.inc');
  }
  $info = $image->info;
  if (!$info) {
    return FALSE;
  }
  #dpm("run imagefilter imagefilter($image->resource, $filter, $arg1, $arg2, $arg3)");

  imagesavealpha($image->resource, TRUE);

  # This is a bit silly really, php internals complain if it's given TOO MANY args!
  # Should refactor this and not be so lazy.
  if (!is_null($arg2) && !is_null($arg3)) {
    return imagefilter($image->resource, $filter, $arg1, $arg2, $arg3);
  }
  else if (!is_null($arg2) && is_null($arg3)) {
    return imagefilter($image->resource, $filter, $arg1, $arg2);
  }
  else if (is_null($arg2) && is_null($arg3)) {
    return imagefilter($image->resource, $filter, $arg1);
  }
}


/**
 * Implementation of imagecache_hook_form()
 *
 * @param $action array of settings for this action
 * @return a form definition
 */
function imagecache_convert_form($action) {
  $form = array(
    'help' => array(
      '#type' => 'markup',
      '#value' => t("If you've been using transparencies in the process, the result may get saved as a PNG (as the image was treated as a one in in-between processes). If this is not desired (file sizes may get too big) you should use this process to force a flatten action before saving. "),
    ),
    'help2' => array(
      '#type' => 'markup',
      '#value' => t("For technical reasons, changing the file format within imagecache does <em>not</em> change the filename suffix. A png may be saved as a *.jpg or vice versa. This may confuse some browsers and image software, but most of them have no trouble. "),
    ),
    'format' => array(
      '#title' => t("File format"),
      '#type' => 'select',
      '#default_value' => isset($action['format']) ? isset($action['format']) : 'image/png',
      '#options' => imagecache_file_formats(),
    )
  );
  return $form;
}

/**
 * Implementation of theme_hook() for imagecache_ui.module
 */
function theme_imagecache_convert($element) {
  $formats = imagecache_file_formats();
  return t("Convert to") ." : ". $formats[$element['#value']['format']];
}

/**
 * Implementation of hook_image()
 *
 * Process the imagecache action on the passed image
 */
function imagecache_convert_image(&$image, $data = array()) {
  $formats = imagecache_file_formats();
  $image->info['mime_type'] = $data['format'];
  $image->info['extension'] = $formats[$data['format']];
  return TRUE;
}

function imagecache_file_formats() {
  return array('image/jpeg' => 'jpg', 'image/gif' => 'gif', 'image/png' => 'png');
}