While every possible subsystem needs an initialization call, all that
does is add the actual initialization task to the render graph system.
This allows the render graph to be fully configurable, initializing only
those subsystems that the graph needs.
Scripted initialization is still separated from startup as render graph
creation needs various resources (eg, attachments) defined before
creating render and compute passes, but all those need to be created
before the subsystems can actually start up.
It's not perfect (double fog on translucent surfaces, the
scatter/absorption isn't right, and no local lighting on the fog
itself), but it at least seems to look ok.
Gotta be sure :)
With the new system mostly up and running (just bsp rendering and
descriptor sets/layout handling to go, and they're independent of the
old render pass system), the old system can finally be cleared out.
I had debated putting the blending in the compose subpass or a separate
pass but went with the separate pass originally, but it turns out that
removing the separate pass gains 1-3% (5-15/545 fps in a timedemo of
demo1).
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.
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.
