http://llmotorsport.se/resources/4.3/scripts/gallery/jquery.ds.animate.clip-1.0.js

1(function ($) {
2	var clipPattern = /rect\(([0-9]{1,})(px|em)[, ]+([0-9]{1,})(px|em)[, ]+([0-9]{1,})(px|em)[, ]+([0-9]{1,})(px|em)\)/;
3
4	/**
5	* Creates an array of clip settings where the values correspond to:
6	* rect([0] [1], [2] [3], [4] [5], [6] [7])
7	*/
8	function getClip (style) {
9		var parsed = clipPattern.exec(style),
10		result = $.map(parsed.slice(1), function (text, index) {
11				if ((index % 2) == 0)
12				{
13					return parseInt(text);
14				}
15				else
16				{
17					return text;
18				}
19			});
20		return result;
21	}
22
23	function makeClip(array) {
24		var result = "rect(" + [
25				array[0] + array[1],
26				array[2] + array[3],
27				array[4] + array[5],
28				array[6] + array[7]
29			].join(",") + ")";
30		return result;
31	}
32	
33	$.fx.step.clip = function (fx) {
34	
35		if (!fx.clipTarget) {
36			fx.clipStart = getClip($.curCSS(fx.elem, "clip"));
37			fx.clipTarget = getClip(fx.end);
38		}
39
40		var update = makeClip([
41				parseInt((fx.pos * (fx.clipTarget[0] - fx.clipStart[0])) + fx.clipStart[0]), fx.clipTarget[1],
42				parseInt((fx.pos * (fx.clipTarget[2] - fx.clipStart[2])) + fx.clipStart[2]), fx.clipTarget[3],
43				parseInt((fx.pos * (fx.clipTarget[4] - fx.clipStart[4])) + fx.clipStart[4]), fx.clipTarget[5],
44				parseInt((fx.pos * (fx.clipTarget[6] - fx.clipStart[6])) + fx.clipStart[6]), fx.clipTarget[7]
45			]);
46		
47		$(fx.elem).css("clip", update);
48	}
49})(jQuery);