[Mesa-dev] [PATCH 2/3] glsl: add AMD_vertex_shader_layer support

[Matt Turner]

On Wed, May 1, 2013 at 8:41 PM, Jordan Justen <jljusten at gmail.com> wrote:
> On Tue, Apr 30, 2013 at 10:01 AM, Jordan Justen <jljusten at gmail.com> wrote:
>> On Tue, Apr 30, 2013 at 9:57 AM, Ian Romanick <idr at freedesktop.org> wrote:
>>> On 04/27/2013 04:32 PM, Jordan Justen wrote:
>>>>
>>>> This GLSL extension requires that AMD_vertex_shader_layer be
>>>> enabled by the driver.
>>>
>>> Most (all?) extensions also add a preprocessor define.  Can you poke at
>>> AMD's driver to see if GL_AMD_vertex_shader_layer is defined?  If so, then
>>> we need to add it too.
>>
>> Unfortunately, I don't have an AMD card.
>>
>> Anuj tried my piglit test with his AMD card, and found the extension
>> wasn't available.
>
> Anuj updated his driver, and now the extension is available.
>
> Is this series r-b you pending resolution of the define issue?

His question about the preprocessor definition is still unanswered, as
far as I can tell.

e.g., In http://www.opengl.org/registry/specs/ARB/gpu_shader5.txt it says

    Including the following line in a shader can be used to control the
    language features described in this extension:

      #extension GL_ARB_gpu_shader5 : <behavior>

    where <behavior> is as specified in section 3.3.

    New preprocessor #defines are added to the OpenGL Shading Language:

      #define GL_ARB_gpu_shader5        1

This extension spec doesn't say anything about that, but it seems
probable that AMD's driver actually adds the preprocessor stuff, since
it's kind of mean to add a built-in variable to GLSL without a macro
to tell if it's available.