[Mesa-dev] [PATCH 0/5] Gallium: Passing drirc options to create_screen() and fixing Rocket League

[Ilia Mirkin]

On Thu, Jun 22, 2017 at 2:53 PM, Roland Scheidegger <sroland at vmware.com> wrote:
> Am 22.06.2017 um 19:35 schrieb Ilia Mirkin:
>> On Wed, Jun 21, 2017 at 9:58 AM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>>> On Tue, Jun 20, 2017 at 6:54 PM, Marek Olšák <maraeo at gmail.com> wrote:
>>>> The first pipe_screen flag is a drirc option to fix incorrect grass
>>>> rendering in Rocket League for radeonsi. Rocket League expects DirectX
>>>> behavior for partial derivative computations after discard/kill, but
>>>> radeonsi implements the more efficient but stricter OpenGL behavior
>>>> and that will remain our default behavior. The new screen flag forces
>>>> radeonsi to use the DX behavior for that game.
>>>
>>> For those of us following along at home... can you provide a brief
>>> reminder of what the DX behavior is, and how does it differ from GL
>>> behavior? In case one might want to fix this for nouveau (if a fix is
>>> needed at all)...
>>
>> From what I gather, this is the difference between discard exiting
>> immediately in that thread and keeping going.
>>
>> Does this make sense to be surfaced in gallium via a tgsi program
>> property? That way, e.g. a GL extension could be written to expose
>> that program property.
>
> I suppose it would make sense, that way this could be exposed cleanly.
> But of course the apps would have to use the extension, otherwise the
> override is just in a different place (and in theory not just glsl,
> vulkan works the same too).

Right... I was thinking Wine. Or some porting company.

  -ilia