[Mesa-dev] [PATCH V3] glapi: add GL_OES_geometry_shader extension

[Tapani Pälli]

On 01/14/2016 01:11 AM, Ilia Mirkin wrote:
> On Wed, Jan 13, 2016 at 3:55 AM, Tapani Pälli <tapani.palli at intel.com> wrote:
>> On 01/13/2016 10:29 AM, Lofstedt, Marta wrote:
>>>
>>>
>>>> -----Original Message-----
>>>> From: ibmirkin at gmail.com [mailto:ibmirkin at gmail.com] On Behalf Of Ilia
>>>> Mirkin
>>>> Sent: Tuesday, January 12, 2016 7:09 PM
>>>> To: Marta Lofstedt
>>>> Cc: mesa-dev at lists.freedesktop.org; Romanick, Ian D; Lofstedt, Marta
>>>> Subject: Re: [PATCH V3] glapi: add GL_OES_geometry_shader extension
>>>>
>>>> On Tue, Jan 12, 2016 at 9:13 AM, Marta Lofstedt
>>>> <marta.lofstedt at linux.intel.com> wrote:
>>>>>
>>>>> From: Marta Lofstedt <marta.lofstedt at intel.com>
>>>>>
>>>>> Add xml definitions for the GL_OES_geometry_shader extension and
>>>>> expose the extension for OpenGL ES 3.1.
>>>>>
>>>>> V3: Added dependency to OES_shader_io_blocks and updated to correct
>>>>> Khronos extension number.
>>>>
>>>> May I ask why you did this? OES_shader_io_blocks is a purely shader
>>>> compiler/linker feature, I expect it will be enabled whenever GLES 3.1 is
>>>> enabled, no? Why would it be tied to geometry shaders? Sure, geometry
>>>> shaders require it to work, but just because you have
>>>> OES_shader_io_blocks
>>>> doesn't necessarily mean you also have geometry shaders...
>>>>
>>> My intension was to address the co-dependency between oes_geometry_shader
>>> and oes_shader_io_block.
>>> But as always, you are right Ilia. The dependency issue need to be fixed
>>> in the driver.
>>>
>>> So, please disregard this V3, I will push the V2 with the changes
>>> suggested by Ilia in the comments.
>>>
>>> FYI here are quotes from the oes_geometry_shader specification:
>>> " OES_shader_io_blocks or EXT_shader_io_blocks is required."
>>
>>
>> IMO according to this it looks OES_shader_io_blocks is a valid requirement
>> as that functionality is not part of OpenGL ES 3.1.
>
> Sure. But that has little bearing on the discussion here --
>
> OES_shader_io_blocks is a compiler feature, not a backend feature. In
> order for any backend to expose OES_geometry_shader, the
> OES_shader_io_blocks ext needs to be done. But just because it is done
> doesn't mean you have geometry shaders.

Right, that is correct. For a moment there I forgot how this table works 
:) There needs to be separate enable bits for these.

> So you have to make sure that not only does the backend support
> geometry shaders, but the core supports OES_shader_io_blocks before
> you expose OES_geometry_shader. That doesn't seem too onerous.
>
>    -ilia
>

// Tapani