[Mesa-dev] [PATCH 01/10] mesa: add infra for ARB_shader_texture_image_samples

[Ian Romanick]

On 08/27/2015 08:48 PM, Ilia Mirkin wrote:
> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
>  src/mesa/main/extensions.c | 1 +
>  src/mesa/main/mtypes.h     | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
> index a57d5ba..1f7d542 100644
> --- a/src/mesa/main/extensions.c
> +++ b/src/mesa/main/extensions.c
> @@ -159,6 +159,7 @@ static const struct extension extension_table[] = {
>     { "GL_ARB_shader_stencil_export",               o(ARB_shader_stencil_export),               GL,             2009 },
>     { "GL_ARB_shader_storage_buffer_object",        o(ARB_shader_storage_buffer_object),        GL,             2012 },
>     { "GL_ARB_shader_subroutine",                   o(ARB_shader_subroutine),                   GLC,            2010 },
> +   { "GL_ARB_shader_texture_image_samples",        o(ARB_shader_texture_image_samples),        GL,             2014 },

I'm not sure we can expose this yet.  The spec says:

    "Dependencies

        OpenGL 4.3 is required.

        OpenGL Shading Language 4.30 is required"

I wasn't involved with the development of this spec at all, so I don't
know why the requirement is so high.  Images were added in 4.2.
Certainly every other implementation that has this extension will also
have 4.3 or higher.

It seems weird since the related extensions only require 4.2
(GL_ARB_shader_image_size) or 3.1 (GL_ARB_texture_multisample).

Since you have tests... do you know what other implementations do if you
only have #version 130?  If nobody enforces the #version 430 requirement
from the spec, I'll propose some changes to the spec.

>     { "GL_ARB_shader_texture_lod",                  o(ARB_shader_texture_lod),                  GL,             2009 },
>     { "GL_ARB_shading_language_100",                o(dummy_true),                              GLL,            2003 },
>     { "GL_ARB_shading_language_packing",            o(ARB_shading_language_packing),            GL,             2011 },
> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
> index a172952..1ff2d55 100644
> --- a/src/mesa/main/mtypes.h
> +++ b/src/mesa/main/mtypes.h
> @@ -3765,6 +3765,7 @@ struct gl_extensions
>     GLboolean ARB_shader_stencil_export;
>     GLboolean ARB_shader_storage_buffer_object;
>     GLboolean ARB_shader_subroutine;
> +   GLboolean ARB_shader_texture_image_samples;
>     GLboolean ARB_shader_texture_lod;
>     GLboolean ARB_shading_language_packing;
>     GLboolean ARB_shading_language_420pack;