循环的下一部分控制像素坐标的设置，条件是当前时间帧在起始帧之后。
The next loop section controls setting pixels coordinates only if the frame at that position is greater than the start frame.
如果升序排序匹配x坐标的当前值，则设置右击(right - swipe)条件。
If the ascending sort matches the current value of X coordinates, the right-swipe condition is set.
接下来，旋转和恢复这个矩阵；然后，使用translate设置与当前坐标系统的偏移量(这是从之前旋转和转换的矩阵应用的)，并绘制一个红色椭圆。
Next, rotate and store this matrix; then, offset from the current coordinate system with translate (which is applied from the previously rotated and translated matrices), and draw a red ellipse.
应用推荐