这个代码实现了一个比较简单的小游戏--大家小时候玩的用笔画图。可以让笔离开纸面，让笔接触纸面等等一系列命令。另外还扩展了它的命令集。-This code implements a relatively simple game- you use a pen drawing of a child to play. Can leave the pen on paper, so that contact paper pen a series of commands and so on. It also