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

[Ilia Mirkin]

On Tue, Sep 8, 2015 at 11:05 PM, Ian Romanick <idr at freedesktop.org> wrote:
> 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.

FWIW we ignore these (IMHO silly) version requirements on almost every
extension that has them. I know I've personally added support for
EXT_polygon_offset_clamp into compat contexts, whereas the ext
specifies GL 3.3 minimum.

I'll give it a shot on NVIDIA and see what happens... my tests might
require GL 3.2 because I didn't want to deal with the various
differences that happen otherwise.

  -ilia