对于直线/多边形的裁剪实验，要求实现标准矩形窗口的裁剪，窗口边界由键盘输入或鼠标确定，直线/多边形都是任意的。裁剪后的图形要准确，不能多或者少点。-For the straight line/polygon clipping experiments required to achieve the standard rectangular window clipping, the window borders from the keyboard or mouse to determine a st