请分别给出直线的三种不同位置情况，测试实验代码是否存在问题，有的话请调试改正。 可能的话，可以尝试实现梁友栋裁剪算法。-Please give a straight line, respectively, three different locations, the test code to test if there is a problem, so please correct debugging. If possible, Dong LIANG You can try to achieve cutting algorithm.