[Piglit] [PATCH 2/2] arb_direct_state_access: New test for GetCompressedTextureImage.

[Ilia Mirkin]

On Tue, Feb 17, 2015 at 4:45 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> On Tue, Feb 17, 2015 at 4:34 PM, Ian Romanick <idr at freedesktop.org> wrote:
>> "Dependencies
>>
>>     OpenGL 2.0 is required."
>>
>> This means Mesa will need a flag for the extension because there are
>> pre-2.0 drivers.  Every DSA function will need to check the flag and
>> possibly generate GL_INVALID_OPERATION.
>>
>> If we only support core profile (and always enable it in core profile),
>> the functions won't even be put in the dispatch table for non-core.  No
>> flag, and no checks in the functions.
>>
>> So, the $64,000.00 question is: Do we care to support DSA on the few
>> cards that can do 2.0 but not 3.1?
>
> Here's a view of some of the hardware that's stuck in GL2-land... not
> exhaustive:
>
> http://people.freedesktop.org/~imirkin/glxinfo/glxinfo.html#p=compat
>
> So that's basically pre-gen6 intel, NV4x (GeForce 6000 / 7000 series),
> AMD/ATI r300-r500, and the Adreno gpu's. (And presumably VC4.) Click
> around the diff mesa versions, I don't have every hw for every mesa
> version.
>
> What's the downside of enabling this in GL1.x drivers BTW? e.g. nv3x
> won't report GL2 (in Mesa) due to NPOT, and all the GeForce <= 4
> series due to lack of... features. Not that I really care either way,
> but just want to make sure there's a reason for it.
>
> Cheers,
>
>   -ilia

Oh, and an additional thought, if we make it core profile-only, then
it will not be available in compat profile on any hardware, even the
latest. I think people are far from done using compat contexts, and
this would unnecessarily restrict the software that can make use of
this extension.

  -ilia