一个封装了GPC（经典的多边形逻辑运算的库），并且包含求多边形方向、重心、多边形面积、点与多边形关系的功能-a package of GPC (Polygon classic logic operation of the library), and contains polygon seeking direction and the center, polygon area, point and polygon relations fu

一个MFC的多边形类, 一个MFC的多边形类, -MFC class a polygon, a polygon MFC class, a class MFC polygon, a polygon MFC class,