Removed the BlitType enum and getBlitType() method from RenderObject, and replaced them with setTransparent(). This was done to reduce redundant code, since ManagedSurface can already pick between a transparent and regular blit depending on whether the provided source surface has a transparent color set. Also added the correct transparent color for The Vampire Diaries, and the transparent color for nancy1 now gets calculated on the fly.
Made all states (Scene, Credits, Help, etc.) singletons, as well as subclasses of a common State parent with a proper state switching API. Moved the OnPause virtual function from RenderObject to ActionRecord and hooked it into the state switching code. Also got rid of the NancyEngine pointer that got passed around between most classes, and replaced it with several convenience macros. As a result of these changes action records that render to the viewport no longer disappear after opening the menu, and state changes feel snappier.
Rewrote most of the engine using a much more object-oriented approach and using more of ScummVM's common classes. This design deviates quite a lot from the original engine's, but should be more maintainable and extensible in the future.