This is a software renderer prototype. It could be used as base class for renderer which implements platform specific drawing. Avoid using it in your applications unless no other choise. It uses CPU to perform drawing on in-memory bitmaps and thus can be slow in applications with lots of controls. Don't use it in debug builds, acceptable speed could be achieved only in release builds with speed optimization. For the example of how it could be used please see the Windows GDI renderer source code.