Sort Points by clockwise Angle

    Points[4] = {...};
    Point origin;

...

    // Sort Points by Angles
    for(int m=0; m<3; m++)
        for (int i = m + 1; i < 4; i++)
        {
            if (GetClockwiseAngle(Points[i], origin) < GetClockwiseAngle(Points[m], origin);)
            {               
                SwapPoint(Points, i, m);   
            }
        }
       
...

double GetClockwiseAngle(Point point, Point origin)
{
    double angle = 0.0;
    angle = atan2(point.Y - origin.Y, point.X - origin.X) * 180 / M_PI;;

    return angle;
}