(function(jQuery) {
    jQuery.fx.step.clip = function(fx) {
        if (fx.state == 0) {
            var cRE = /rect\(([0-9\.]+)(px|em) ([0-9\.]+)(px|em) ([0-9\.]+)(px|em) ([0-9\.]+)(px|em)\)/;
            fx.start = cRE.exec(fx.elem.style.clip.replace(/,/g, ''));
            fx.end = cRE.exec(fx.end);
        }
        if (fx.start && fx.end) {
            var sarr = new Array(), earr = new Array(), spos = fx.start.length, epos = fx.end.length, emOffset = fx.start[ss + 1] == 'em' ? (parseInt($(fx.elem).css('fontSize')) * 1.333 * parseInt(fx.start[ss])) : 1;
            for (var ss = 1; ss < spos; ss += 2) { sarr.push(parseInt(emOffset * fx.start[ss])); }
            for (var es = 1; es < epos; es += 2) { earr.push(parseInt(emOffset * fx.end[es])); }
            fx.elem.style.clip = 'rect(' +
			            parseInt((fx.pos * (earr[0] - sarr[0])) + sarr[0]) + 'px ' +
			            parseInt((fx.pos * (earr[1] - sarr[1])) + sarr[1]) + 'px ' +
			            parseInt((fx.pos * (earr[2] - sarr[2])) + sarr[2]) + 'px ' +
			            parseInt((fx.pos * (earr[3] - sarr[3])) + sarr[3]) + 'px)';
        }
    }
})(jQuery);