[Mesa-dev] [PATCH 1/2] mesa: GL_EXT_texture_norm16 extension plumbing

[Tapani Pälli]

On 17.04.2018 21:11, Ilia Mirkin wrote:
> On Tue, Apr 17, 2018 at 1:52 PM, Ian Romanick <idr at freedesktop.org> wrote:
>> On 04/17/2018 05:19 AM, Ilia Mirkin wrote:
>>> On Mon, Apr 16, 2018 at 11:22 PM, Tapani Pälli <tapani.palli at intel.com> wrote:
>>>> On 17.04.2018 02:42, Ilia Mirkin wrote:
>>>>> differentiating the case "have NV_image_formats but not
>>>>> EXT_texture_norm16"?
>>>>
>>>> I had a version that added another boolean but since both of these
>>>> extensions require GL ES 3.1 it seemed to me that it would be unlikely to
>>>> have platform to support 3.1 but not EXT_texture_norm16 (?)
>>>
>>> Then why are there separate enables for this and NV_image_formats in
>>> the gl_extensions object?
>>>
>>> Note that doing this properly here is a bit tricky -- it's not like
>>> one would do "#extension GL_EXT_texture_norm16: enable". So you'd have
>>> to check in the GL context for whether it's enabled somehow.
>>>
>>> [As an aside, any impl that supports ARB_shader_image_load_store will
>>> support all of this. I don't know what the practical restrictions are
>>> on ES hardware -- Adreno does norm16 just fine, but others might not?]
>>
>> I guess if this is restricted to GLES 3.1+, it should be fine to skip an
>> explicit enable.  When Tapani asked me about this on IRC, I was thinking
>> this would be more generally enabled.  There's certainly GLES 2.0
>> hardware in Mesa that cannot do this extension.
> 
> The extension itself nominally requires ES 3.1 in the first place.
> Adreno A3xx hardware could do it otherwise (it doesn't currently
> expose ES 3.1, and it's unlikely it ever will, although I think
> technically it could with a kludge here and there).
> 
> We could just expose it unconditionally for ES 3.1, and then when some
> hardware comes along that can't do it, worry about it then?
> 
> Mainly I'm trying to avoid non-working toggles.
> 

FWIW that's fine for me, I'll send a v2 with checks in place for gles31 
and add some more tests.

// Tapani