whyyyyyyyyyy
> Note If you use CopySubresourceRegion with a depth-stencil buffer or a multisampled resource, you must copy the whole subresource.
(same for D3D12 CopyTextureRegion)
this is really messing with my goal of rendering reflections into an atlas (there's no fb fetch either which is the reason for the copy)
(vkCmdBlitImage seems to support partial rect copies out of depth/stencil images however? so why not d3d?)