[Mesa-dev] [PATCH] gallium: add support for layered rendering

[Marek Olšák]

On Sat, Jun 1, 2013 at 2:42 AM, Roland Scheidegger <sroland at vmware.com> wrote:
> Am 01.06.2013 01:22, schrieb Christoph Bumiller:
>> On 01.06.2013 01:02, Alex Deucher wrote:
>>> On Fri, May 31, 2013 at 6:54 PM, Roland Scheidegger <sroland at vmware.com> wrote:
>>>> Am 31.05.2013 23:43, schrieb sroland at vmware.com:
>>>>> From: Roland Scheidegger <sroland at vmware.com>
>>>>>
>>>>> Since pipe_surface already has all the necessary fields no interface
>>>>> changes are necessary except adding a new shader semantic value
>>>>> (TGSI_SEMANTIC_LAYER), though add a pipe capability bit for it as well.
>>>>> (Note that what GL knows as "gl_Layer" variable d3d10 is naming
>>>>> "RENDER_TARGET_ARRAY_INDEX")
>>>>> ---
>>>>>  src/gallium/docs/source/screen.rst         |    2 ++
>>>>>  src/gallium/include/pipe/p_defines.h       |    3 ++-
>>>>>  src/gallium/include/pipe/p_shader_tokens.h |    3 ++-
>>>>>  3 files changed, 6 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/src/gallium/docs/source/screen.rst b/src/gallium/docs/source/screen.rst
>>>>> index 683080c..b74b237 100644
>>>>> --- a/src/gallium/docs/source/screen.rst
>>>>> +++ b/src/gallium/docs/source/screen.rst
>>>>> @@ -168,6 +168,8 @@ The integer capabilities:
>>>>>    since they are linked) a driver can support. Returning 0 is equivalent
>>>>>    to returning 1 because every driver has to support at least a single
>>>>>    viewport/scissor combination.
>>>>> +* ``PIPE_CAP_LAYERED_RENDERING``: Whether rendering to multiple layers is
>>>>> +  supported using layer selection by the TGSI_SEMANTIC_LAYER shader variable.
>>>>>
>>>>>
>>>>>  .. _pipe_capf:
>>>>> diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
>>>>> index 8af1a84..c359a9e 100644
>>>>> --- a/src/gallium/include/pipe/p_defines.h
>>>>> +++ b/src/gallium/include/pipe/p_defines.h
>>>>> @@ -508,7 +508,8 @@ enum pipe_cap {
>>>>>     PIPE_CAP_QUERY_PIPELINE_STATISTICS = 81,
>>>>>     PIPE_CAP_TEXTURE_BORDER_COLOR_QUIRK = 82,
>>>>>     PIPE_CAP_MAX_TEXTURE_BUFFER_SIZE = 83,
>>>>> -   PIPE_CAP_MAX_VIEWPORTS = 84
>>>>> +   PIPE_CAP_MAX_VIEWPORTS = 84,
>>>>> +   PIPE_CAP_MULTIPLE_LAYERS = 85
>>>>>  };
>>>> Actually I don't think is a good name, PIPE_CAP_LAYERED_RENDERING might
>>>> be better?
>>>> I'm open to just about any suggestion though :-).
>>> FWIW, I prefer PIPE_CAP_LAYERED_RENDERING as well.  Other colors:
>>>
>>> PIPE_CAP_RENDER_TARGET_INDEX
>>> PIPE_CAP_RENDER_TARGET_ARRAY_INDEX
>>> PIPE_CAP_RENDER_TARGET_LAYERS
>>
>> Or PIPE_CAP_GS_LAYER_SELECTION to make it clear that the driver doesn't
>> support GL_AMD_vertex_shader_layer ?
>
> Actually now that you mention GS I think we could probably get rid of
> the cap bit entirely and just depend on the PIPE_SHADER_GEOMETRY query
> to expose this, as it's pretty much tied to it anyway?

Yes, the geometry shader query is sufficient.

Marek