class Image {
	private $img = null;
	private $thumb = null;
	var $height = 0;
	var $width = 0;
	
	function __construct($file) {
		if (! is_readable($file) ) throw new Exception('Nie mogę odczytać pliku '.$file);
		
		if ( eregi('\.jpg', $file) ) $this->img = imagecreatefromjpeg($file);
		elseif ( eregi('\.png', $file) ) $this->img = imagecreatefrompng($file);
		elseif ( eregi('\.gif', $file) ) $this->img = imagecreatefromgif($file);
		else throw new Exception("Nieznany format pliku $file");
		
		$size = getimagesize($file);
		$this->width = $size[0];
		$this->height = $size[1];
	}
	
	function resize ($nwidth, $nheight = 0) {
		if (! $nwidth && !$nheight) exit;
		if ($nwidth == 0)
			$nwidth = round($this->width * ($nheight / $this->height));
		elseif ($nheight == 0)
			$nheight = round($this->height * ($nwidth / $this->width));
			
		$nimg = imagecreatetruecolor($nwidth, $nheight);
		
		if (! imagecopyresampled($nimg, $this->img, 0, 0, 0, 0, $nwidth, $nheight, $this->width, $this->height) )
			return false;
		
		unset($this->img);
		$this->img = $nimg;
		
		return true;
	}
	
	function makethumb($width, $height) {
		if (! $width && !$height) exit;
		
		$cwidth = round($this->width * ($height / $this->height));
		$cheight = round($this->height * ($width / $this->width));
		
		$hmargin = ($width == 0) || ($cwidth < $width) ? 0 : ($width - $cwidth) / 2;
		$vmargin = ($height == 0) || ($cheight < $height) ? 0 : ($height - $cheight) / 2;
		
		if (! $height ) $height = $cheight;
		if (! $width ) $width = $cwidth;
		
		$nimg = imagecreatetruecolor($width, $height);
		
		echo "h: $hmargin, v: $vmargin\n[{$this->width}, {$this->height}]";
		echo "$width, $height";
		
		if (! imagecopyresampled($nimg, $this->img, $hmargin, $vmargin, 0, 0, $vmargin ? $width : $cwidth, $hmargin ? $height : $cheight, $this->width, $this->height) )
			return false;
		
		unset($this->thumb);
		$this->thumb = $nimg;
		$this->width = $width;
		$this->height = $height;
		
		return true;
	}
	
	function saveas($file, $thumbfile = '') {
// 		if (! is_writable($file) ) throw new Exception('Nie można było utworzyć pliku '.$file);
		
		if ( eregi('\.jpg', $file) ) {
			imagejpeg($this->img, $file, 97);
			if ($this->thumb && $thumbfile) imagejpeg($this->thumb, $thumbfile, 97);
		}
		elseif ( eregi('\.png', $file) ) {
			imagepng($this->img, $file);
			if ($this->thumb && $thumbfile) imagepng($this->thumb, $thumbfile);
		}
		elseif ( eregi('\.gif', $file) ) {
			imagegif($this->img, $file);
			if ($this->thumb && $thumbfile) imagegif($this->thumb, $thumbfile);
		}
		else throw new Exception("Nieznany format pliku $file");
	
		return true;
	}
}