It's a bit flaky for particles, especially at higher frame rates, but
that's due to supporting only 64 overlapping pixels. A reasonable
solution is probably switching to a priority heap for the "sort" and
upping the limit.
This required making the texture set accessible to the vertex shader
(instead of using a dedicated palette set), which I don't particularly
like, but I don't feel like dealing with the texture code's hard-coded
use of the texture set. QF style particles need something mostly for the
smoke puffs as they expect a texture.
This gets the pipelines loaded (and unloaded on shutdown). Probably the
easy part :P. Still need to sort out the command buffers,
synchronization, and particle generation (and probably a bunch else
that's not coming to mind).