Spline类就是Cardinal样条曲线了,这个类里面记录了4个控制点:m_startControlPoint, m_startPoint, m_endPoint, m_endControlPoint, 分别按顺序对应Pk-1, Pk, Pk+1, Pk+2, 由于Cardinal是用多个线段去模拟曲线,所以我们在这里取20个点,这样,在Pk 和 Pk+1之间,有20个样本点,用画直线的方法将这些点按顺序连起来,连成的曲线段就是我们所要的Cardinal 曲线了-Spline class is Cardinal spline curve, and the class which recorded four control points: m_startControlPoint, m_startPoint, m_endPoint, m_endControlPoint, respectively, the corresponding sequence Pk-1, Pk, Pk+1, Pk+2, the Cardinal is more than a line to the simulation curve, we get 20 points here, so between the Pk and Pk+1, 20 sample points, with the draw line method in order to link these points, and even into the curve segment Cardinal is we want the curve