<?php
/*
*	Pt (PHP Toolkit)
*	Copyright (C) 2008  Dinu Florin
*
*	Pt 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 3 of the License, or
*	any later version.
*
*	Pt 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 Pt.  If not, see <http://www.gnu.org/licenses/>.
*/
/**
*	This file contains the Crop filter class.
*	
*	@author		Dinu Florin <contact@florindinu.ro>
*	@package	Modules
*	@subpackage	Images
*/

/**
*	Crop filter.
*	Crop an image starting at an absolute or relative point and having an absolute size crop area.
*
*	@author		Dinu Florin	<contact@florindinu.ro>
*	@package	Modules
*	@subpackage	Images
*/
class CropImage extends AbstractImageFilter
{
	protected $width;
	protected $height;
	protected $x;
	protected $y;

	/**
	*	Constructor.
	*
	*	@param	mixed	$x		Position of crop region, use an integer for absolute positioning or a string ("x%") for relative positioning.
	*	@param	mixed	$y		Position of crop region, use an integer for absolute positioning or a string ("y%") for relative positioning
	*	@param	number	$width	The width of the cropping region.
	*	@param	number	$height	The height of the cropping region.
	*/
	public function __construct($x, $y, $width, $height)
	{
		assert('is_numeric($x) or is_string($x)');
		assert('is_numeric($y) or is_string($y)');
		assert('is_numeric($width)');
		assert('is_numeric($height)');

		$this->width	= $width;
		$this->height	= $height;
		$this->x		= $x;
		$this->y		= $y;
	}

	/**
	*	Apply to an image
	*
	*	@param	Image	$image	The image to apply the filter to
	*/
	public function applyTo(Image $image)
	{
		$img = $image->getResource();
		$imgw = imagesx($img);
		$imgh = imagesy($img);

		//Calculate the position
		if(is_string($this->x) && substr($this->x, -1, 1) == '%')
		{
			$w = (int)$this->x;
			if($w>0) $this->x = floor($w/100*$imgw);
		}
		if(is_string($this->y) && substr($this->y, -1, 1) == '%')
		{
			$h = (int)$this->y;
			if($h>0) $this->y = floor($h/100*$imgh);
		}
		if($this->x > $imgw || $this->y > $imgh) {trigger_error('ImageCrop: x or y out of bounds', E_USER_WARNING);}

		//Crop the image
		$newImg = imagecreatetruecolor($this->width, $this->height);
		imagecopy($newImg, $img, 0, 0, $this->x, $this->y, $this->width, $this->height);
		
		$image->setResource($newImg);
	}
}
?>