Coding: Spline editor

This is a basic spline editor I wrote in C++, using SDL for pixel drawing. Splines are smooth lines that are used in many applications, especially in programs like 3D Studio MAX, Adobe Illustrator and Macromedia Flash (where splines are called vectors). Splines are also used in games: many animations are done using them and the famous curved surfaces in Quake 3 are based on some form of splines.

The specific types of splines I draw in this little program are Cardinal splines and Hermite splines. Hermite splines take a list of points and derivatives and draw a spline from that. Cardinal splines are a specialisation of this, only here the derivatives are calculated from the points. My little program draws them and makes it possible to do basic editing of Cardinal Splines. The two images below are drawn using my spline editor.