该代码可以实现类似笨鸟先飞游戏，就是点击鼠标时，主角往上飞，不点击时，以一定的速率往下落，无论是往上飞还是往下飞都有可能触碰到障碍物，所以要一直控制它的走向。(This code can be achieved similar to the game, is the click of a mouse, the protagonist fly up, don't click, falling at a certain rate, whether up or down to fly could touch obstacles, so want to control it.)