在定义了窗口之后，我们只需将窗口内的图形显示出来，对于窗口之外的图形我们是不关心的。因此，必须将窗口外的图形裁剪下去。在本资料中，实现如下对直线段进行裁剪的算法：Cohen-Sutherland算法、中点分割算法、梁友栋-Barsky算法，并且利用Sutherland-Hodgman算法实现对多边形的裁剪，最后，实现当裁剪域是任意凸多边形时的裁剪算法。-In the definition of the window, we simply window graphics are displayed, in addition to window graphics we are not concerned. Therefore, the need to cut down the graphics outside the window. In this data, to achieve the following sections of the cut line algorithm: Cohen-Sutherland algorithm, the mid-point division algorithm, Liangyou Dong-Barsky algorithm, and using Sutherland-Hodgman polygon clipping algorithm, and finally, to achieve when the cutting domain is arbitrary when the convex polygon clipping algorithm.