VEngine-Trigger.js

var mid = function (v) {
            var cx = 0;
            var cy = 0;

            for (var i = 0; i < v.length; i++) {
                cx += v[i].x;
                cy += v[i].y;
            }

            cx /= v.length;
            cy /= v.length;

            return new Vector2(cx, cy);
        };

        var sigma = function (v, Target) {
            var s = 0;

            v[v.length] = v[0];

            for (var i = 0; i < v.length - 1; i++) {
                s += Vector2.AngleBetween(Target, v[i], v[i + 1]);
            }

            return s;
        };

        var Verts = [new Vector2(100, 100), new Vector2(200, 100), new Vector2(200, 200), new Vector2(100, 200)];

        var VertsCenter = mid(Verts);
        var CursorCenter = Input.mousePosition;

        var SigmaDist = sigma(Verts, VertsCenter);
        var SigmaDistCursor = sigma(Verts, CursorCenter);

        GUI.Label(new Rect(50, 50, 100, 100), (Math.round(SigmaDist) == Math.round(SigmaDistCursor)), GUI.customSkin.freeLabel);

        GUI.Box(new Rect(VertsCenter.x, VertsCenter.y, 10, 10), "");
        GUI.Box(new Rect(CursorCenter.x, CursorCenter.y, 10, 10), "");

        for (var i = 0; i < Verts.length; i++) {
            GUI.Box(new Rect(Verts[i].x, Verts[i].y, 10, 10), "");
        }