This removes the following for both Buffer and Texture:
- The builder's SetInitialUsage
- The object's FreezeUsage and TransitionUsage methods
- The CommandBuffer Transition<Object>Usage methods
All samples and tests are simplified as a result. This also obsoletes
the UsageValidationTest which is removed.
Some validation was dependent on "current usage" and hasn't been
reintroduced for implicit transitions yet:
- Buffers can be used while mapped
- Swapchain textures can be used after they have been presented.
Validation for these will involve collecting all the resources used by a
command buffer and will be done in a follow-up patch.
With this commit the Vulkan backend completely ignores the explicit
barrier commands passed from the frontend, and generates its own
pipeline barriers.
Right now it encodes each barrier just before the resources are used,
which is quite bad but will be optimized later.
This commit also makes the frontend command buffer validation perform
the checks necessary for implicit barriers (although they are redundant
with checks for explicit barriers) because the tracking can pre-compute
pass usage information that's useful for the Vulkan backend.
Tests for usage validation inside passes will be added once the concept
of transition is removed from the API.
This as this is the first command handled by the Vulkan backend, this
commit also introduces the b:✌️:CommandBUffer class and implements
b:✌️:Queue::Submit.
Also enables the BufferSetSubData tests that are now passing on Vulkan
even though the buffer transitions are unimplemented.
This introduce a new FencedDeleter service as part of the Device
objects that tracks when resources are no longer used and deletes them.
BufferVk takes advantage of this to defer the deletion of its handle
that was previously incorrectly delete directly in ~BufferVk.
