def CubicOut(start=0.0, finish=1.0):
    """
    Cubically increasing, starts very fast : f(x) = 1 + (x-1)^3
    """

    def cubic_out_easing(sprite, delta):
        delta -= 1.0
        return start + (delta * delta * delta + 1.0) * (finish - start)

    return cubic_out_easing