[Mesa-dev] [PATCH] mesa: initialize renderbuffer fields even if AllocStorage fails
brianp at vmware.com
Mon May 14 09:59:58 PDT 2012
On 05/14/2012 10:44 AM, Marek Olšák wrote:
> On Mon, May 14, 2012 at 4:40 PM, Brian Paul<brianp at vmware.com> wrote:
>> On 05/12/2012 10:11 AM, Marek Olšák wrote:
>>> It may fail with an unsupported format, but that's not an allowed case
>>> RenderbufferStorage may fail.
>> I've read your comment several times but I still can't quite understand the
>> whole issue.
>> The intention was that AllocStorage() should never fail because of the
>> internalFormat value. We do error checking of internalFormat earlier in
>> renderbuffer_storage(). Then the driver chooses a hw format that best
>> matches the requested internalFormat.
> The driver is r600g and the format is GL_RGB9_E5
> (EXT_texture_shared_exponent). There is sampler support, but no
> colorbuffer support. The format is quite special, no other format
> matches it well, though I guess any RGB float format would work.
> However the spec doesn't require renderbuffer support despite the fact
> the format is accepted in glRenderbufferStorage.
This looks like a spec/documentation issue. The GL 3.0 spec (page
180) says GL_RGB9_E5 is a texture-only format. But the
GL_EXT_texture_shared_exponent spec says it's accepted by
I just hacked up a quick test for the NVIDIA driver. Passing
GL_RGB9_E5 to glRenderbufferStorage() generates a GL_INVALID_OPERATION
error. Mesa will need some changes if we want to generate the same
error, rather than GL_INVALID_ENUM.
Could you test w/ AMD's driver?
> The problem is st_choose_renderbuffer_format returns PIPE_FORMAT_NONE,
> because it looks for GL_RGB9_E5 with PIPE_BIND_RENDER_TARGET support.
> I don't think we should allocate a renderbuffer if we know the user
> won't be able to render to it. The other option is to pretend that we
> allocated something, so that glCheckFramebufferStatus can fail later.
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