<?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 Scale filter class.
*	
*	@author		Dinu Florin <contact@florindinu.ro>
*	@package	Modules
*	@subpackage	Images
*/

/**
*	Scale filter.
*	Scale an image to absolute or relative dimensions keeping the aspect ratio or not. It will scale the image to the maximum size that will
*	fit in the dimensions given. This will either shrink or grow the image to achieve it's goal.
*
*	@author		Dinu Florin	<contact@florindinu.ro>
*	@package	Modules
*	@subpackage	Images
*/
class ScaleImage extends AbstractImageFilter
{
	protected $width;
	protected $height;
	protected $absolute;
	protected $keepAR;

	/**
	*	Constructor.
	*
	*	@param	mixed	$width	The new width of the image, use an integer for an absolute size or a string ("w%") for a relative size.
	*	@param	mixed	$height	The new height of the image, use an integer for an absolute size or a string ("h%") for a relative size.
	*	@param	boolean	$keepAR	Keep the image aspect ratio when scaling (default=true)
	*/
	public function __construct($width, $height, $keepAR=true)
	{
		assert('is_string($width) or is_numeric($width)');
		assert('is_string($height) or is_numeric($height)');
		assert('is_bool($keepAR)');

		$this->width	= $width;
		$this->height	= $height;
		$this->keepAR	= $keepAR;
	}

	/**
	*	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 desired dimensions
		if(is_string($this->width) && substr($this->width, -1, 1) == '%')
		{
			$w = (int)$this->width;
			if($w>0) $this->width = $w/100*$imgw;
		}
		if(is_string($this->height) && substr($this->height, -1, 1) == '%')
		{
			$h = (int)$this->height;
			if($h>0) $this->height = $h/100*$imgh;
		}

		//Calculate the actual dimensions
		if($this->keepAR)
		{
			$width = $this->width;
			$height = $this->height;

			$w = round($imgw * $this->height / $imgh);
			$h = round($imgh * $this->width / $imgw);

			if(($this->height-$h)<($this->width-$w))
			{
				$width = $w;
			}
			else
			{
				$height = $h;
			}
		}
		else
		{
			$width = $this->width;
			$height = $this->height;
		}

		//Scale the image
		$newImg = imagecreatetruecolor($width, $height);
		imagecopyresampled($newImg, $img, 0, 0, 0, 0, $width, $height, $imgw, $imgh);
		
		$image->setResource($newImg);
	}
}
?>