https://msdn.microsoft.com/en-us/library/windows/desktop/ms533826(v=vs.85).aspx The purpose of hit testing is to determine whether the cursor is over a given object, such as an icon or a button. The following example creates a plus-shaped region by f
/*函数的输入:(1)当前点的坐标p(2)区域顶点数组pt[]:(3)顶点数nCount 输出: 在区域内返回TRUE,否则返回FALSE. Point类型是一个结构: struct Point { 类型 x;//此处类型根据采用的经纬度类型决定. 类型 y; };*/BOOL PtInPolygon(Point p, Point pt[], int nCount){ int nCross = 0; for (int i = 0; i < nCount; i++) {