document.createElement("canvas").getContext("2d").prototype.$3D = {
    __objects: [],
    point: function (x, y, z) {
        this.x = x;
        this.y = y;
        this.z = z;
        this.x2d = x < (cnv.width / 2) ? x + (z / ((cnv.width + cnv.height) / 2)) : x - (z / ((cnv.width + cnv.height) / 2));
        this.y2d = y < (cnv.height / 2) ? y + (z / ((cnv.width + cnv.height) / 2)) : y - (z / ((cnv.width + cnv.height) / 2));
        this.isPoint = true;
    },
    Point: function (x, y, z, color) {

    }
}

alert(typeof document.createElement("canvas").getContext("2d").prototype);