For now, at least (I have some ideas to possibly reduce the numbers and
also to avoid the need for actual limits). I've seen gmsp3v2 use over
500 lights at once (it has over 1300), and I spent too long figuring out
that weird light behavior was due to the limit being hit and lights
getting dropped (and even longer figuring out that more weird behavior
was due to the lack of shadows and the world being too bright in the
first place).
This leaves only the one conditional in the shader code, that being the
distance check. It doesn't seem to make any noticeable difference to
performance, but other than explosion sprites being blue, lighting
quality seems to have improved. However, I really need to get shadows
working: marcher is just silly-bright without them, and light levels
changing as I move around is a bit disconcerting (but reasonable as
those lights' leaf nodes go in and out of visibility).
My VersaPro doesn't support more than 32 per-stage samplers (lavapipe).
This is a small part of getting Vulkan to run on lavapipe and even in
itself is rather incomplete.
Standard quake has just linear, but the modding community added inverse,
inverse-square (raw and offset (1/(r^2+1)), infinite (sun), and
ambient (minlight). Other than the lack of shadows, marcher now looks
really good.
This gets the shaders needed for creating shadow maps, and the changes
to the lighting pipeline for binding the shadow maps, but no generation
or reading is done yet. It feels like parts of various systems are
getting a little big for their britches and I need to do an audit of
various things.
That was... easier than expected. A little more tedious that I would
have liked, but my scripting system isn't perfect (I suspect it's best
suited as the output of a code generator), and the C side could do with
a little more automation.
Other than dealing with shader data alignment issues, that went well :).
Nicely, the implementation gets the explicit scaling out of the shader,
and allows for a directional flag.
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.
