[Mesa-dev] [PATCH 1/9] gallium: Add PIPE_CAP_BUFFER_SAMPLER_VIEW_RGBA_ONLY

[Nicolai Hähnle]

On 19.01.2016 10:45, Fredrik Höglund wrote:
> On Tuesday 19 January 2016, Nicolai Hähnle wrote:
>>
>> On 18.01.2016 18:50, Ilia Mirkin wrote:
>>> On Mon, Jan 18, 2016 at 5:22 PM, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
>>>> diff --git a/src/gallium/drivers/nouveau/nv30/nv30_screen.c b/src/gallium/drivers/nouveau/nv30/nv30_screen.c
>>>> index 933330f..1ae557d 100644
>>>> --- a/src/gallium/drivers/nouveau/nv30/nv30_screen.c
>>>> +++ b/src/gallium/drivers/nouveau/nv30/nv30_screen.c
>>>> @@ -75,6 +75,8 @@ nv30_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
>>>>          return 1;
>>>>       case PIPE_CAP_MAX_VERTEX_ATTRIB_STRIDE:
>>>>          return 2048;
>>>> +   case PIPE_CAP_BUFFER_SAMPLER_VIEW_RGBA_ONLY:
>>>> +      return 0;
>>>>       /* supported capabilities */
>>>>       case PIPE_CAP_TWO_SIDED_STENCIL:
>>>>       case PIPE_CAP_ANISOTROPIC_FILTER:
>>>> diff --git a/src/gallium/drivers/nouveau/nv50/nv50_screen.c b/src/gallium/drivers/nouveau/nv50/nv50_screen.c
>>>> index 712835c..99d7ae6 100644
>>>> --- a/src/gallium/drivers/nouveau/nv50/nv50_screen.c
>>>> +++ b/src/gallium/drivers/nouveau/nv50/nv50_screen.c
>>>> @@ -121,6 +121,8 @@ nv50_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
>>>>          return 256;
>>>>       case PIPE_CAP_TEXTURE_BUFFER_OFFSET_ALIGNMENT:
>>>>          return 1; /* 256 for binding as RT, but that's not possible in GL */
>>>> +   case PIPE_CAP_BUFFER_SAMPLER_VIEW_RGBA_ONLY:
>>>> +      return 0;
>>>>       case PIPE_CAP_MIN_MAP_BUFFER_ALIGNMENT:
>>>>          return NOUVEAU_MIN_BUFFER_MAP_ALIGN;
>>>>       case PIPE_CAP_MAX_VIEWPORTS:
>>>> diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
>>>> index 7211df9..612f1c0 100644
>>>> --- a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
>>>> +++ b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
>>>> @@ -111,6 +111,8 @@ nvc0_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
>>>>          return 256;
>>>>       case PIPE_CAP_TEXTURE_BUFFER_OFFSET_ALIGNMENT:
>>>>          return 1; /* 256 for binding as RT, but that's not possible in GL */
>>>> +   case PIPE_CAP_BUFFER_SAMPLER_VIEW_RGBA_ONLY:
>>>> +      return 0;
>>>>       case PIPE_CAP_MIN_MAP_BUFFER_ALIGNMENT:
>>>>          return NOUVEAU_MIN_BUFFER_MAP_ALIGN;
>>>>       case PIPE_CAP_MAX_VIEWPORTS:
>>>
>>> I would greatly appreciate it if you could stick these into the
>>> "unsupported" list of caps -- each of nv30/nv50/nvc0 should have one,
>>> of varying length. (Same applies to the other cap you're adding.)
>>
>> Do you really want that? I actually put them aside on purpose, because
>> the somewhat unusual sense of the cap means that the return value of 1
>> is something unsupported. Of course, one might argue that I should have
>> changed the boolean sense and renamed it to something like
>> PIPE_CAP_BUFFER_SAMPLER_VIEW_SWIZZLES.
>
> That is actually the name I was going to use at first (minus the s).
> But then it occurred to me that it would be misleading, since this
> is not about pipe_sampler_view::swizzle_r/g/b/a.

It's about both the swizzles and the formats, isn't it? If it were only 
the formats, the deficiency could be fixed by using the swizzles.

Naming is hard. I'm happy with keeping it the way it is.

Cheers,
Nicolai