There are some issues with the light renderers getting mangled, and only
the first light is even touched (just begin and end of render pass), but
this gets a lot of the framework into place.
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).
The parsing of light data from maps is now in the client library, and
basic light management is in scene. Putting the light loading code into
the Vulkan renderer was a mistake I've wanted to correct for a while.
The client code still needs a bit of cleanup, but the basics are working
nicely.
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).
Multiple render passes are needed for supporting shadow mapping, and
this is a huge step towards breaking the Vulkan render free of Quake,
and hopefully will lead the way for breaking the GL renderers free as
well.
Modern maps can have many more leafs (eg, ad_tears has 98983 leafs).
Using set_t makes dynamic leaf counts easy to support and the code much
easier to read (though set_is_member and the iterators are a little
slower). The main thing to watch out for is the novis set and the set
returned by Mod_LeafPVS never shrink, and may have excess elements (ie,
indicate that nonexistent leafs are visible).
Any sun (a directional light) is in the outside node, which due to not
having its own PVS data is visible to all nodes, but that's a tad
excessive. However, any leaf node with sky surfaces will potentially see
any suns, and leaf nodes with no sky surfaces will see the sun only if
they can see a leaf that does have sky surfaces. This can be quite
expensive to calculate (already known to be moderately expensive for
just the camera leaf node (singular!) when checking for in-map lights)
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.
Still "some" more to go: a pile to do with transforms and temporary
entities, and a nasty one with host_cbuf. There's also all the static
block-alloc lists :/
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.
