* This is apparently in a format capability class to R8 it seems, and since we
don't expect anyone to be rendering to A8 let alone in MSAA, there's no point
in testing this.
* When displaying mip 0 of a texture at less than 100% zoom we linear sampling,
but we don't want to linear sample across slices. Adding a half pixel offset
in z ensures we sample precisely on the slice itself.
* We preserve each API's interpretation of bit order for packed formats like
RGBA4 or R5G6B5 when displaying the raw data in the UI, but when we need to
proxy it or save to disk, we always transform to D3D's order as standard.
* This allows us to proxy them reliably because we always have a standard bit
order and APIs that need a different order transform when fetching data to the
standard format, or setting proxy data from the standard format.
* It's not particularly scalable and can be brittle to driver changes, and we
can use targeted specific pixel tests to check what we really want - to see if
the output has rendered correctly.
* Overlay tests still check files directly - this is a future refactor to
remove.
* When the renderpass has an initialLayout = UNDEFINED, that applies to the
whole resource on 3D textures even if we're only rendering to a slice at a
time
* These tests ensure that texture rendering works correctly for all different
types of texture types, and for all formats, across different APIs, including
across a remote-proxy connection.
baldurk