Polygon Clipping Against A Circular Window
基于圆形窗口的简单多边形裁剪算法

A simple and practical clipping algorithms for a polygon P is offered based on a circular window V. It considers the edges of the polygon as directed lines, and studies the problem of deciding the area edge of P clipping by V, based on the intersection point concept of in edges and out edges of the polygon vertices. The theorems about what is the inner part of the polygon P within a circular window V are presented.