Cardinal spline in Qt + OpenGL, with simple car animation.
Please install Qt Creator, then open MyLab.pro with double click, the project would be loaded. It would be very easy to build with Qt Creator (By ctrl+B).
Draw Curve with Pen / Eraser / Manipulator Tools.
Change Grain number to change the number of division.
Change tau number to change the strength of tendency to be stright line on control points.
You could also play a simple animation to test the curve division and change the speed of the small car.