Matteo Bruni (@Mystral) commented about dlls/d3dx9_36/tests/surface.c:
+ if (FAILED(hr)) + skip("Failed to create D3DFMT_X8L8V8U8 texture, hr %#lx.\n", hr); + else + { + hr = IDirect3DTexture9_GetSurfaceLevel(tex, 0, &surf); + ok(hr == D3D_OK, "Failed to get the surface, hr %#lx.\n", hr); + + SetRect(&rect, 0, 0, 2, 2); + hr = D3DXLoadSurfaceFromMemory(surf, NULL, NULL, pixdata_a8b8g8r8_2, D3DFMT_A8B8G8R8, 8, NULL, &rect, + D3DX_FILTER_NONE, 0); + todo_wine ok(hr == D3D_OK, "Unexpected hr %#lx.\n", hr); + + /* + * The luma channel here doesn't do RGB->Luma conversion, it just + * copies the alpha channel directly as UNORM. V8 and U8 are snorm, + * pulled from r/g respectively. The blue channel is empty. I guess, technically, it's the `X` channel to be set to 0.
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/6360#note_80586