I guess it's not quite bindless as the texture index is a push constant,
but it seems to work well (and I may have fixed some full-bright issues
by accident, though I suspect that's just my imagination, but they do
look good).
BSP textures are now two-layered with the albedo and emission in the two
layers rather than two separate images. While this does increase memory
usage for the textures themselves (most do not have fullbright pixels),
it cuts down on image and image view handles (and shader resources).
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.
Since vulkan supports 32-bit indexes, there's no need for the
shenanigans the EGL-based glsl renderer had to go through to render bsp
models (maps often had quite a bit more than 65536 vertices), though the
reduced GPU memory requirements of 16-bit indices does have its
advantages.
Getting close to understanding (again) how it all works. I only just
barely understood when I got vulkan's renderer running, but I really
need to understand for when I modify things for shadows. The main thing
hurdle was tinst, but that was dealt with in the previous commit, and
now it's just sorting out the mess of elechains and elementss.
Loading is broken for multi-file image sets due to the way images are
loaded (this needs some thought for making it effecient), but the
Blender environment map loading works.
They're unlit (fullbright, but that's nothing new for quake), but
working nicely. As a bonus, sort out the sky pass (forced to due to the
way command buffers are used).
After getting lights even vaguely working for alias models, I realized
that it just wasn't going to be feasible to do nice lighting with
forward rendering. This gets the bulk of the work done for deferred
rendering, but still need to sort out the shaders before any real
testing can be done.
The sky texture is loaded with black's alpha set to 0. While this does
hit both layers, the screen is cleared to black so it shouldn't be a
problem (and will allow having a skybox behind the sheets).
Glow map and sky sheet and cube need to wait until I can get some
default textures going, but the world is rendering correctly otherwise
(though a tad dark: need to do a gamma setting).
