[Mesa-dev] EXT_gpu_shader4 glsl

[Dave Airlie]

>> Hi guys,
>>
>> So I've been noticing there are a number of inconsistencies
>> between EXT_gpu_shader4 and GLSL1.30, are you planning on
>> implementing EXT_gpu_shader4?
>>
>> EXT_gpu_shader4 appears to define "unsigned" and can also use
>> texture2D to sample from integer samplers.
>
> There are a few functional differences between GLSL 1.30 and
> EXT_gpu_shader4.  At the very least, EXT_gpu_shader4 supports TexBOs
> and UBOs.  I think there are a couple other things as well.  We're
> targeting GLSL 1.30 and OpenGL 3.0 in the next major release, so there
> will really only be a short period where we have one but not the other
> in Mesa master.
>
> I think that we may fill-in some of the missing EXT_gpu_shader4 bits
> after GLSL 1.30 is done.  My plan was for that to primarily be a
> vehicle to get the simpler / older TexBO and UBO extensions working as
> we work towards GLSL 1.40.
>
>> My main worry is we end up needing GL3.0 entrypoints when we are
>> missing float texture for example, so we would want to expose
>> EXT_gpu_shader4 then I suppose, but then we would want to fix up
>> the GLSL handling for it.
>
> What do you mean?

Some of us can't ship advertising GL3.0, it would be nice if that
didn't make life harder for apps that don't require all the GL3.0
features but just want EXT_gpu_shader4 type features. If we don't
advertise GL3.0 we won't get all the new entry points unless we
advertise EXT_gpu_shader4.

Dave.