Light styles and shadows aren't implemented yet.
The map's entities are used to create the lights, and the PVS used to
determine which lights might be visible (ie, the surfaces they light).
That could do with some more improvements (eg, checking if a leaf is
outside a spotlight's cone), but the concept seems to work.
It's not used yet as work needs to be done to better support generic
entities, but this is the next step to real-time lighting (though, to be
honest, I expect it will be too slow to be usable).
Static lights are yet to come (so the screen is black most of the time),
but dynamic lights work very nicely (and look very good) despite the
falloff being incorrect.
While I could reconstruct the position from the screen coords and depth,
this is easier and good enough for now. Reconstruction is an
optimization thing.
Lighting doesn't actually do lights yet, but it's producing pixels.
Translucent seems to be working (2d draw uses it), and compose seems to
be working.
