[Mesa-dev] [PATCH 5/8] main: enable NV_primitive_restart extension by default

[Marek Olšák]

On Fri, May 11, 2012 at 7:17 PM, Brian Paul <brianp at vmware.com> wrote:
> On 05/11/2012 11:08 AM, Marek Olšák wrote:
>>
>> I think a more preferable way to enable an extension for everybody by
>> default is to do something like this:
>>
>>> diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
>>> index a843a40..71b7721 100644
>>> --- a/src/mesa/main/extensions.c
>>> +++ b/src/mesa/main/extensions.c
>>> @@ -298,7 +298,7 @@ static const struct extension extension_table[] = {
>>>     { "GL_NV_light_max_exponent",
>>> o(NV_light_max_exponent),                   GL,             1999 },
>>>     { "GL_NV_packed_depth_stencil",
>>> o(EXT_packed_depth_stencil),                GL,             2000 },
>>>     { "GL_NV_point_sprite",                         o(NV_point_sprite),
>>>                       GL,             2001 },
>>> -   { "GL_NV_primitive_restart",
>>>  o(NV_primitive_restart),                    GL,             2002 },
>>> +   { "GL_NV_primitive_restart",                    o(dummy_true),
>>>                        GL,             2002 },
>>>     { "GL_NV_texgen_reflection",
>>>  o(NV_texgen_reflection),                    GL,             1999 },
>>>     { "GL_NV_texture_barrier",
>>>  o(NV_texture_barrier),                      GL,             2009 },
>>>     { "GL_NV_texture_env_combine4",
>>> o(NV_texture_env_combine4),                 GL,             1999 },
>>> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
>>> index 06ca0d5..8086bb5 100644
>>> --- a/src/mesa/main/mtypes.h
>>> +++ b/src/mesa/main/mtypes.h
>>> @@ -2982,7 +2982,6 @@ struct gl_extensions
>>>     GLboolean NV_fragment_program_option;
>>>     GLboolean NV_light_max_exponent;
>>>     GLboolean NV_point_sprite;
>>> -   GLboolean NV_primitive_restart;
>>>     GLboolean NV_texture_barrier;
>>>     GLboolean NV_texgen_reflection;
>>>     GLboolean NV_texture_env_combine4;
>>
>>
>> And fixing all occurences of gl_extensions::NV_primitive_restart. Both
>> ways are equivalent though, so it's really just about whether we
>> should allow drivers to disable the extension.
>
>
> FWIW, I know of at least one application which performs faster with the
> vmware driver when NV_primitive_restart is disabled (and the app does it's
> own work-around) rather than to use the software-based primitive restart
> path.
>
> So setting MESA_EXTENSION_OVERRIDE=-GL_NV_primitive_restart should be an
> option.  The o(dummy_true) convention might prevent that, but I haven't
> tested that...

In that case, I think we should disable it in the state tracker if
there's no driver support. If it's faster for svga, it's very likely
faster for the other DX9-level drivers too.

Marek