$(window).load(function(){
	
	
	var supportCanvas = 'getContext' in document.createElement('canvas');
	
	var slides = $('#slideshow li'),
		current = 0,
		slideshow = {width:0,height:0};

	setTimeout(function(){
		
		window.console && window.console.time && console.time('Generated In');
		
		if(supportCanvas){
			$('#slideshow img').each(function(){

				if(!slideshow.width){
					
					slideshow.width = this.width;
					slideshow.height = this.height;
				}
				
				createCanvasOverlay(this);
			});
		}
		
		window.console && window.console.timeEnd && console.timeEnd('Generated In');
		
		setInterval(function(){
			var li			= slides.eq(current),
				canvas		= li.find('canvas'),
				nextIndex	= 0;

			if($(this).hasClass('next')){
				nextIndex = current >= slides.length-1 ? 0 : current+1;
			}
			else {
				nextIndex = current <= 0 ? slides.length-1 : current-1;
			}

			var next = slides.eq(nextIndex);
			
			if(supportCanvas){

					canvas.fadeIn(function(){
					next.show();
					current = nextIndex;
					
			
					li.fadeOut(function(){
						li.removeClass('slideActive');
						canvas.hide();
						next.addClass('slideActive');
					});
				});
			}
			else {
				
							
				current=nextIndex;
				next.addClass('slideActive').show();
				li.removeClass('slideActive').hide();
			}
		},4000);
		
	},100);

	
	function createCanvasOverlay(image){

		var canvas			= document.createElement('canvas'),
			canvasContext	= canvas.getContext("2d");
		
		canvas.width = slideshow.width;
		canvas.height = slideshow.height;
		
		canvasContext.drawImage(image,0,0);
		

		var imageData	= canvasContext.getImageData(0,0,canvas.width,canvas.height),
			data		= imageData.data;
		
		
		for(var i = 0,z=data.length;i<z;i++){
			
			data[i] = ((data[i] < 128) ? (2*data[i]*data[i] / 255) : (255 - 2 * (255 - data[i]) * (255 - data[i]) / 255));
			data[++i] = ((data[i] < 128) ? (2*data[i]*data[i] / 255) : (255 - 2 * (255 - data[i]) * (255 - data[i]) / 255));
			data[++i] = ((data[i] < 128) ? (2*data[i]*data[i] / 255) : (255 - 2 * (255 - data[i]) * (255 - data[i]) / 255));
			
			++i;
		}
		
		canvasContext.putImageData(imageData,0,0);
		
		image.parentNode.insertBefore(canvas,image);
	}
	
});