Vulkan does support rendering without a fragment shader, and this seems
to work fine on current drivers. This commit gets rid of the last
embedded shader binary in libvkd3d, and may have a slight performance
advantage on hardware/drivers able to take advantage of the absence of a
fragment shader.
When a heap was released at the same time as the last resource on that
heap, it was possible for both to see each other's
refcount/resource_count as 0 and both would try to destroy the heap.
Avoid that by converting "resource_count" to an internal refcount, which
holds an extra +1 if the main refcount is nonzero. The final release
will then be synchronized between the two since both will operate on
"internal_refcount".
This effectively moves "null_event_cond" from struct d3d12_fence and
"latch" from struct vkd3d_waiting_event together into a separate
structure, as well as storing the signalling function in struct
vkd3d_waiting_event instead of getting it from struct d3d12_device. I
think that largely makes sense on its own, but storing the signalling
function in struct vkd3d_waiting_event also allows us to more easily
implement d3d12_device_SetEventOnMultipleFenceCompletion() in a
subsequent commit.
Since 4a94bfc2f6 we segregate
different D3D12 descriptor types in different Vulkan descriptor sets.
This change was introduced to reduce descriptor wasting when
allocating a new descriptor pool; that can be very useful when
using virtual heaps, which have to often cycle through many
descriptors, but it is expected to have limited impact for Vulkan
heaps, given that in that case most descriptors are allocated through
the descriptor heap rather than through the command allocator.
Instead, it has a rather detrimental effect with Vulkan heaps,
because it tends to use many more Vulkan descriptor sets than
necessary, often with just a handful of descriptors each. This
causes a regression on some Vulkan implementations that support
too few descriptor sets.
With this change we revert to a situation similar to before,
stuffing all the descriptors that do not live in a root
descriptor table in as few descriptor sets as possible (at most
one or two, depending on whether push descriptors are used).
We're already implicitly using it for image layouts in which
either depth or stencil is writeable and the other is not.
Correspondingly, add the _KHR suffix in those cases, so the
extension usage is more evident.
According to the Vulkan Hardware Database, only four reports
without this extension were filed since 2023, and all of them
for configurations we likely don't target.
