When operating in "bindless" mode, the device will own 2 descriptor
heaps, one for views, and one for samplers. Every time a view is
created (image view, buffer view), a slot is allocated for it out
of the device view heap for each usage type (sampled vs storage).
Then, in a future change, descriptor sets will just contain view/
sampler indices instead of actual descriptors. Instead of copying
these to a cmdbuf-owned descriptor heap, we can directly bind the
descriptor set as a buffer. We'll also modify shaders to perform
an indirection and index into the device heap.
Buffers also get views set up on creation. In a perfect world, we
could just put addresses/sizes in the descriptor set, but DXIL
doesn't support loading from addresses, we need descriptors. When
robust buffer access is disabled *or* descriptor set buffer views
reference the remainder of the buffer, we can just re-use a view
from the buffer and use an offset.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21913>
Jesse Natalie
4c4431b674