[Mesa-dev] [PATCH] mesa: Loosen glBlitFramebuffer restrictions on depthstencil buffers (v2)

[Christoph Bumiller]

On 20.01.2012 12:45, Henri Verbeet wrote:
> On 20 January 2012 03:24, Eric Anholt <eric at anholt.net> wrote:
>>> So is it also allowed to blit from S8Z24 to Z24S8 ? Could we also allow
>>> to blit from RGBA8 to BGRA8 then, please ?
>> That's already allowed.
>>
> Yeah, but not for multisampled framebuffers, unless RGBA8 and BGRA8
> are considered identical (ARB_fbo):
>
>     If SAMPLE_BUFFERS for either the read framebuffer or
>     draw framebuffer is greater than zero, no copy is performed and an
>     INVALID_OPERATION error is generated if the dimensions of the source
>     and destination rectangles provided to BlitFramebuffer are not
>     identical, or if the formats of the read and draw framebuffers are
>     not identical.
Yes, sorry, I didn't realize this only applied to multisample buffers.

I just tested again and the blob conveniently ignores the matching
formats condition altogether.

The point is that I'd really like to support GL_RGBA8 as red-first,
regardless of the window format.
There might even be window systems that force either the one or the
other, and then we could never be compatible with both and support the
established behaviour of NOT doing 2 blits (first to temporary
framebuffer where we can be sure the format matches and then to the
window) when resolving.