多边形常用算法模块 1. 判断多边形是否简单多边形2. 检查多边形顶点的凸凹性 3. 判断多边形是否凸多边形 4. 求多边形面积5. 判断多边形顶点的排列方向，方法一 6. 判断多边形顶点的排列方向，方法二 7. 射线法判断点是否在多边形内8. 判断点是否在凸多边形内-Does the polygon commonly used algorithm module 1. judgements polygons whether simple polygon. 2. inspections polygons apex convex-concave.　3.　judgements polygons whether raised - polygon. 4. ask the polygon area. 5. judgements polygons apex the arrangement direction, the method 1. 6.　judgements polygons apex arrangement direction, the method 2. 7. beams　methods to sentence the break point whether. 8. sentences the break　point in the polygon whether in raised - polygon