用vc编写的一个B样条曲线算法，根据鼠标输入的点动态绘制B样条曲线，并且可以修改控制点，从而修改曲线形状., A B transect curve algorithm compiles which with vc, inputs the spot tendency according to the mouse to draw up the B transect curve, and may revise the control point, thus revision curve shape