利用一些API技巧实现的临摹软件，效果就像小时候用一张薄纸描课本上的画一样，但是鼠标确实没有铅笔头那么方便。-Use some techniques to achieve the copying software API, the effect is like a child with a tissue as described textbook picture, but the mouse does not pencil so easy, haha.