这个源代码是用来实现图形之间的基本运算的，包括求交集、并集、差集等等。而且图形的形状也可以任意选择，可以是圆、线段、点、多边形等等。-the source code is used to achieve the basic graphics operations, including for intersection and set difference, and so on. The shape and graphics can choose freely, it can be won, segment, points, polygons, and so on.