Subdivision Surface

Develop a program that loads a polygonal mesh from a file, applies an adjustable number of Loop subdivisions to it, and displays the result. Wireframe display is sufficient. You can for instance employ .x as a file format and use the correponding DirectX to load a mesh. (As usual, choose any programming language or graphics API you find appropriate.)

Remember to first organize your thoughts on paper and to use a great deal of exceptions and assertions.

Possible extensions:

Treat meshes with boundaries correctly (subdivision rules)
Create creases
Allow the use to drag vertices by mouse
Also subdivide texture coordinates and employ them for texturing