Other than the rather bad shadow acne, this is actually quake itself
working nicely. Still need to get directional lights working for
community maps, and all sorts of other little things (hide view model,
show player, fix brush backfaces, etc).
This takes care of the type punning issue by each pass using the correct
sampler type with the correct view types bound. Also, point light and
spot light shadow maps are now guaranteed to be separated (it was just
luck that they were before) and spot light maps may be significantly
smaller as their cone angle is taken into account. Lighting is quite
borked, but at least the engine is running again.