jquery眼睛随鼠标旋转

主要js代码
<script>        var getAngle = function (Xc, Yc, Xa, Ya, Xb, Yb) {
            var v1x = Xb - Xc;
            var v1y = Yb - Yc;
            var v2x = Xa - Xc;
            var v2y = Ya - Yc;
            return 180 * (Math.atan2(v1x, v1y) - Math.atan2(v2x, v2y)) / Math.PI
        };
        var left_center_offset = {
            left: 30,
            top: 82
        },
right_center_offset = {
    left: 96,
    top: 80
},
radius = 10;
        var setEyeOffset = function (event) {
            var offset = $(".eye_wrapper").offset();
            var x1 = offset.left + left_center_offset.left;
            var y1 = offset.top + left_center_offset.top;
            var x2 = offset.left + right_center_offset.left;
            var y2 = offset.top + right_center_offset.top;
            var n1 = event.clientX - x1;
            var m1 = -(event.clientY - y1);
            var k1 = Math.atan2(m1, n1);
            var n2 = event.clientX - x2;
            var m2 = -(event.clientY - y2);
            var k2 = Math.atan2(m2, n2);
            var x11 = (Math.cos(k1) * radius + x1).toFixed(0);
            var y11 = ((-Math.sin(k1) * radius) + y1).toFixed(0);
            $(".eye-left").offset({
                left: x11,
                top: y11
            });
            var x22 = (Math.cos(k2) * radius + x2).toFixed(0);
            var y22 = ((-Math.sin(k2) * radius) + y2).toFixed(0);
            $(".eye-right").offset({
                left: x22,
                top: y22
            })
        };
        $(window).mousemove(setEyeOffset);</script>