When building acceleration structures, we need to have an
VkAccelerationStructureKHR object, but the D3D12 API just uses a plain
VA = ID3D12Resource::GetGPUVA() + offset.
For this to work, we need to resolve the VA back to VkBuffer + offset.
The only VkBuffer we can lookup is the original backing memory
allocation in the VA map, and that allocation itself must own a view
map, since we cannot tie the VA to any specific ID3D12Resource.
Since creating an RTAS is not the common path, we allocate the view map
on-demand with CAS.
Signed-off-by: Hans-Kristian Arntzen <post@arntzen-software.no>
This is designed to work with actual device addresses if supported by
the Vulkan implementation.
Signed-off-by: Philip Rebohle <philip.rebohle@tu-dortmund.de>