This uniform is used in two cases:
* Non-buffered rendering in Vulkan, software transform
* Non-buffered rendering in D3D11 level 9 on Windows Phone, software transform
- which I don't think anyone builds for anymore
Nice to not have it in the main uniform buffer, but mainly a
demonstrator/test of moving stuff to the new frame-global buffer, and
setting up the infrastructure.
In #16104, we drastically reduced the number of shader variants for
games that use flexible lighting setups. I looked at a few games and it
seems that a lot of games have the same shaders with fog on/off, while
fog is super cheap to compute. So let's just always do it, reducing
vertex shader variants further (though the amount of pipelines will probably
remain the same, since we still specialize the fragment shader).
Might also be worth adding a dynamic bool for the fragment shader, but
if so, doing it separately.
This drastically reduces the shader compile stutter that happens when a lot of new
light setups are created, like on the first punch in Tekken 6.
There's more stuff that might benefit from being made dynamic like this.
These branches are very cheap on modern GPUs since they're branching on
a uniform variable, so no divergence.
Only tested on Vulkan. I think we'll need to keep the old path too for
gpus like Mali-450...
