Use an array of bindtypes rather than the previous situation, which was
a choice of buffer counts, or a heavier builder pattern.
The main thing this unlocks is distinguishing between readonly and
read/write buffers, which is important for DX12.
This is WIP, the Metal part hasn't been done, and the old stuff not
deleted.
Part of #125
Reuse submitted command buffers rather than continually allocating them.
This patch also improves the story across the different backends. On
DX12 it was reusing allocators without resetting them, which could be a
leak. And on Metal the reset "fails," so there's always a new alloc.
This patch gets rid of warnings and runs cargo fmt.
A lot of the warnings were unused items (especially in DX12 land). At
some point we might want to bring some of that back, at which point it
might be useful to refer to what was deleted in this commit.
This patch deallocates command buffers after command submission completes (the same time as other resources are released).
It should be portable and robust on all back-ends, but not necessarily the most efficient. But reuse of command buffers, as well as more efficient allocation on Vulkan and DX12, are for followup work.
These function, but can use some work.
First, the buffer situation is worse than it should be. It should be
possible to create a single readback buffer rather then copy from
gpu-local to host-coherent.
Second, the command buffer `finish_timestamps` call doesn't correlate to
anything in Vulkan, so needs plumbing up through the hub in one form or
other when that happens. I'm inclined to make it ergonomic by doing a
bit of resource tracking that will trigger the appropriate call (and
subsequent host barrier) in the `finish` method on the command buffer.
Create compute pipelines from shader source and descriptor sets. This
gets it to the point where it can run the collatz example.
Still WIP and with rough edges, of course.
Chipping away at the dx12 backend. This should more or less do the
signalling to the CPU that the command buffer is done (ie wire up the
fence). It also creates buffer objects.
