Display class

In this class, only initialize(), shutdown(), and render() contain DirectX specific code. Those same three functions do not include any game-specific code, so it is easy to re-use them in other programs. In general, game-specific code is limited to a calls to methods in other classes that do the real game-specific work. That means that although the Display class could not be re-used in a different game without modification, the modifications required are minimal.

Here is a list of the most important functions in my Display class, along with short descriptions of what they do:

Question: How could you make it easier to reuse this class?