C++ code. Realization of an algorithm for finding an 2D convex hull polygon for input set of 2D points (with glut).

判断点是否在点群形成的多边形范围内，点群排列需要闭合- The purpose of this function is to indicate whether a specified 2D point is inside (returns a 1) a specified 2D polygon or outside(returns a 0).