<?php
	/**
 * @author Gasper Kozak
 * @copyright 2007-2011

    This file is part of WideImage.
		
    WideImage is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 2.1 of the License, or
    (at your option) any later version.
		
    WideImage is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.
		
    You should have received a copy of the GNU Lesser General Public License
    along with WideImage; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    * @package Internal/Operations
  **/
	
	/**
	 * ResizeCanvas operation class
	 * 
	 * @package Internal/Operations
	 */
	class WideImage_Operation_ResizeCanvas
	{
		/**
		 * Returns an image with a resized canvas
		 * 
		 * The image is filled with $color. Use $scale to determine, when to resize.
		 *
		 * @param WideImage_Image $img
		 * @param smart_coordinate $width
		 * @param smart_coordinate $height
		 * @param smart_coordinate $left
		 * @param smart_coordinate $top
		 * @param int $color
		 * @param string $scale 'up', 'down', 'any'
		 * @param boolean $merge
		 * @return WideImage_Image
		 */
		function execute($img, $width, $height, $left, $top, $color, $scale, $merge)
		{
			$new_width = WideImage_Coordinate::fix($width, $img->getWidth());
			$new_height = WideImage_Coordinate::fix($height, $img->getHeight());
			
			if ($scale == 'down')
			{
				$new_width = min($new_width, $img->getWidth());
				$new_height = min($new_height, $img->getHeight());
			}
			elseif ($scale == 'up')
			{
				$new_width = max($new_width, $img->getWidth());
				$new_height = max($new_height, $img->getHeight());
			}
			
			$new = WideImage::createTrueColorImage($new_width, $new_height);
			if ($img->isTrueColor())
			{
				if ($color === null)
					$color = $new->allocateColorAlpha(0, 0, 0, 127);
			}
			else
			{
				imagepalettecopy($new->getHandle(), $img->getHandle());
				
				if ($img->isTransparent())
				{
					$new->copyTransparencyFrom($img);
					$tc_rgb = $img->getTransparentColorRGB();
					$t_color = $new->allocateColorAlpha($tc_rgb);
				}
				
				if ($color === null)
				{
					if ($img->isTransparent())
						$color = $t_color;
					else
						$color = $new->allocateColorAlpha(255, 0, 127, 127);
					
					imagecolortransparent($new->getHandle(), $color);
				}
			}
			$new->fill(0, 0, $color);
			
			
			$x = WideImage_Coordinate::fix($left, $new->getWidth(), $img->getWidth());
			$y = WideImage_Coordinate::fix($top, $new->getHeight(), $img->getHeight());
			
			// blending for truecolor images
			if ($img->isTrueColor())
				$new->alphaBlending($merge);
			
			// not-blending for palette images
			if (!$merge && !$img->isTrueColor() && isset($t_color))
				$new->getCanvas()->filledRectangle($x, $y, $x + $img->getWidth(), $y + $img->getHeight(), $t_color);
			
			$img->copyTo($new, $x, $y);
			return $new;
		}
	}