[Mesa-dev] [PATCH 1/3] gallium: add per-sample interpolation control into rasterizer state

[Marek Olšák]

On Fri, Oct 2, 2015 at 4:12 PM, Roland Scheidegger <sroland at vmware.com> wrote:
> Am 02.10.2015 um 12:19 schrieb Marek Olšák:
>> On Fri, Oct 2, 2015 at 3:13 AM, Roland Scheidegger <sroland at vmware.com> wrote:
>>> Can't say I'm a big fan of doing essentially the same thing with
>>> different methods, but well it's coming from GL, and if it helps some
>>> drivers...
>>>
>>> Acked-by: Roland Scheidegger <sroland at vmware.com>
>>
>> If all drivers start supporting the CAP, we could remove the st/mesa
>> emulation. Just as we could remove the color clamping emulation.
>>
>> Marek
>>
>
> Yes, but that just moves the logic to the drivers. It's still (mostly)
> the same thing handling per-sample inputs, or forcing them to per sample
> via ARB_sample_shading.

Yes, that's the main point. For performance, we should do the
translation to TGSI at link time, so that the GLSL->TGSI overhead can
be removed from draw calls. Because of that, all shader state
dependencies should be moved to and implemented/emulated in drivers.
This will be difficult to do because of the lack of interest from
other driver maintainers, therefore we need CAPs until they realize
it's good for them too.

Marek