asahi: Decompress with format reinterpretation
The internal layout used with compression partially depends on the pixel format. Some limited reinterpretation is definitely allowed (linear vs sRGB views of the same physical format are documented by Apple as allowed). Some reinterpretations are definitely forbidden (R8G8B8A8 vs R32, I think). At some point we'll need to work out the exact rule. I suspect the answer is that "you can reinterpret iff the Channels field matches". Meaning that R8G8B8A8_UNORM
and B8G8R8A8_SINT
would be compatible, but not R16G16_UNORM
. But I haven't tested that.
I'm not sure off hand if texture views are possible with the GL versions we're about to ship (definitely possible with gles3.1, which is where these commits come from). But just in case let's get it right.