Function imageEqual

tests/tests.js:70–110

(left, right, text, callback, delta)

	function imageEqual(left, right, text, callback, delta){
		loadImage(left, function (left){
			left.setAttribute('style', 'border: 2px solid red; padding: 2px;');
			document.body.appendChild(left.cloneNode());

			loadImage(right, function (right){
				right.setAttribute('style', 'border: 2px solid blue; padding: 2px;');
				document.body.appendChild(right);

				left = toCanvas(left);
				right = toCanvas(right);

				if( left.width != right.width ){
					ok(false, text + ' (width: '+left.width+' != '+right.width+')');
				}
				else if( left.height != right.height ){
					ok(false, text + ' (height: '+left.height+' != '+right.height+')');
				}
				else {
					var state = true, pixels = 0, failPixels = 0;
					var leftData = left.getContext('2d').getImageData(0, 0, left.width, left.height);
					var rightData = right.getContext('2d').getImageData(0, 0, left.width, left.height);

					check: for( var y = 0; y < leftData.height; y++ ){
						for( var x = 0; x < leftData.width; x++ ){
							var idx = (x + y * leftData.width) * 4;
							pixels++;
							if( !pixelEqual(leftData.data, rightData.data, idx) ){
								failPixels++;
	//							break check;
							}
						}
					}

					ok(failPixels/pixels < (delta || .01), text + ' (fail pixels: '+ (failPixels/pixels) +')');
				}

				callback();
			});
		});
	}


	function pixelEqual(left, right, idx){