$(document).ready(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){
					// Taking the dimensions of the first image:
					slideshow.width = this.width;
					slideshow.height = this.height;
				}
				createCanvasOverlay(this);
			});
		}
		
		window.console && window.console.timeEnd && console.timeEnd('Generated In');
		
		$('#slideshow .arrow').click(function(){
			var li			= slides.eq(current),
				canvas		= li.find('canvas'),
				nextIndex	= 0;

			// Depending on whether this is the next or previous
			// arrow, calculate the index of the next slide accordingly.
			
			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();
			}
		});
		
	},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);
		

		// Taking the image data and storing it in the imageData array:
		var imageData	= canvasContext.getImageData(0,0,canvas.width,canvas.height),
			data		= imageData.data;
		
		// Loop through all the pixels in the imageData array, and modify
		// the red, green, and blue color values.
		
		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));
			
			// After the RGB elements is the alpha value, but we leave it the same.
			++i;
		}
		
		canvasContext.putImageData(imageData,0,0);
		image.parentNode.insertBefore(canvas,image);
	}

	//start auto advance
	var timeOut = null;

	$('#slideshow .arrow').click(function(e,simulated){

		if(!simulated){
			clearTimeout(timeOut);
		}
	});

	(function autoAdvance(){
		$('#slideshow .next').trigger('click',[true]);	
		timeOut = setTimeout(autoAdvance,12000);		
	})();
	
});