Introduction - If you have any usage issues, please Google them yourself
This application, the user left-click way to order input control point, double-click for ending the left mouse button, draw the mouse input for the control point 4 point 3 Dengju order B-spline curve. Concrete realization of function 1. Draw the control polygon, mark the location of control points 2 curve to the control point sequence of the first and last point as a starting point and end point control polygon of the first side edge and the last one as a starting point and end point tangent 3 in which a change in the position of a control point, with another color to draw the new curve, compared with the original curve.