使用opengl的反馈模式，获得glut函数绘制的曲面上某一曲线的所有点坐标，来形成动画。包括菜单显示、三维显示、运动速度调节等等。-Use opengl feedback mode, get all the coordinates of a point on the curve plotted as a function of surface glut to form animation. Including menu display, three-dimensional display, motion speed adjustment and so on.