def update(self, frame_no):
        """
        Process the animation effect for the specified frame number.

        :param frame_no: The index of the frame being generated.
        """
        if (frame_no >= self._start_frame and
                (self._stop_frame == 0 or frame_no < self._stop_frame)):
            self._update(frame_no)
Process the animation effect for the specified frame number.

        :param frame_no: The index of the frame being generated.