[Mesa-dev] [PATCH 1/2] mesa: Implement ARB_texture_filter_minmax

[Ilia Mirkin]

On Thu, Nov 16, 2017 at 2:49 PM, Ian Romanick <idr at freedesktop.org> wrote:
> On 11/14/2017 02:54 PM, Scott D Phillips wrote:
>> This extension provides a new texture and sampler parameter
>> (TEXTURE_REDUCTION_MODE_ARB) which allows applications to produce
>> a filtered texel value by computing a component-wise minimum (MIN)
>> or maximum (MAX) of the texels that would normally be averaged.
>> ---
>> CTS tests KHR-GL45.texture_filter_minmax_tests.* need a little TLC to
>> pass with this series. Details in VK-GL-CTS issue: 849
>>
>>  src/mesa/main/attrib.c           |  4 ++++
>>  src/mesa/main/extensions_table.h |  1 +
>>  src/mesa/main/formatquery.c      | 10 ++++++++++
>>  src/mesa/main/mtypes.h           |  2 ++
>>  src/mesa/main/samplerobj.c       | 37 +++++++++++++++++++++++++++++++++++++
>>  src/mesa/main/texobj.c           |  2 ++
>>  src/mesa/main/texobj.h           |  2 +-
>>  src/mesa/main/texparam.c         | 33 +++++++++++++++++++++++++++++++++
>>  8 files changed, 90 insertions(+), 1 deletion(-)
>>
>
> [lots of stuff trimmed]
>
>> diff --git a/src/mesa/main/extensions_table.h b/src/mesa/main/extensions_table.h
>> index 5b66e7d30d..c51ad80742 100644
>> --- a/src/mesa/main/extensions_table.h
>> +++ b/src/mesa/main/extensions_table.h
>> @@ -146,6 +146,7 @@ EXT(ARB_texture_env_combine                 , ARB_texture_env_combine
>>  EXT(ARB_texture_env_crossbar                , ARB_texture_env_crossbar               , GLL,  x ,  x ,  x , 2001)
>>  EXT(ARB_texture_env_dot3                    , ARB_texture_env_dot3                   , GLL,  x ,  x ,  x , 2001)
>>  EXT(ARB_texture_filter_anisotropic          , ARB_texture_filter_anisotropic         , GLL, GLC,  x ,  x , 2017)
>> +EXT(ARB_texture_filter_minmax               , ARB_texture_filter_minmax              , GLL, GLC,  x ,  x , 2017)
>
> Is this right?  The extension says OpenGL 3.3 is required, and we don't
> (until Marek is done) do OpenGL 3.3 compatibility profile.

FWIW I took the view that spec writers are lazy on
EXT_polygon_offset_clamp, which had similar text. Is this a bad thing
to do? Should we stick to the text of the specs to the letter?

There are various GL 4.2/4.3 exts which require the previous GL
version as well but we expose them anyways.

IMHO it's reasonable to be relaxed about this, unless there are
obvious interactions that need explicit consideration. [Perhaps that's
the case here, although I can't think of anything.]

Cheers,

  -ilia