[Mesa-dev] [PATCH 18/20] mesa: fill out the ARB_shader_subroutine APIs

[Dave Airlie]

On 23 July 2015 at 15:01, Kenneth Graunke <kenneth at whitecape.org> wrote:
> On Tuesday, July 21, 2015 03:19:25 PM Dave Airlie wrote:
>> From: Dave Airlie <airlied at redhat.com>
>>
>> This fleshes out the APIs, using the program resource
>> APIs where they should match.
>>
>> It also sets the default values to valid subroutines.
>>
>> Signed-off-by: Dave Airlie <airlied at redhat.com>
>> ---
>>  src/mesa/main/shaderapi.c | 450 +++++++++++++++++++++++++++++++++++++++++++++-
>>  src/mesa/main/shaderapi.h |   3 +
>>  2 files changed, 450 insertions(+), 3 deletions(-)
>
> So, one question I have...according to the spec...
>
>    "Subroutine uniform variables are similar to uniform variables, except they
>     are context state rather than program state. Having subroutine uniforms be
>     context state allows them to have different values if the program is used
>     in multiple contexts simultaneously.  There is a set of subroutine
>     uniforms for each shader stage."
>
> but it looks like we're storing them in the shader, rather than
> per-context.  Bug?  Or am I missing something?

No I think it's a bug in that I may have convinced myself the constant
buffer we give to drivers is per context, when it really isn't.

The question is whether this is some feature anyone is ever going to
care about at this point, I'd still like to land this, and I try and
go write a piglit test that isn't crap to test for that case.

>
> At this point I'm just inclined to give everything I haven't reviewed an
> Acked-by: Kenneth Graunke <kenneth at whitecape.org>
>
> I don't think anybody wants to spend much more time on this, and it'd be
> nice to check off the box and move on.

Yup me to :-0

Dave.