[Mesa-dev] [PATCH] main/base_tex_format: Properly handle STENCIL_INDEX1/4/16

[Ilia Mirkin]

On Tue, Mar 3, 2015 at 3:58 PM, Kenneth Graunke <kenneth at whitecape.org> wrote:
> On Monday, March 02, 2015 02:33:31 PM Ilia Mirkin wrote:
>> On Mon, Mar 2, 2015 at 2:32 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
>> >
>> >
>> > On Mon, Mar 2, 2015 at 11:18 AM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>> >>
>> >> Hmmm... I was just looking at this code in connection to attepmting to
>> >> enable ARB_texture_stencil8, and it _seems_ like that should be if
>> >> (ARB_texture_stencil8) -- I didn't see what in ARB_stencil_texturing
>> >> had to do with being able to have a GL_STENCIL_INDEX* internal
>> >> format...
>> >
>> >
>> > I just pushed it because it does fix a bug...  However, you do raise a good
>> > point.  Maybe we should change the i965 driver to use GL_STENCIL_INDEX for
>> > the internal format for our internal stencil buffers.
>>
>> How do you end up with a GL_STENCIL_INDEX internal format in the first
>> place? Without ARB_texture_stencil8 that's not a thing, is it?
>
> Eric added a ctx->Driver.BindRenderbufferTexImage hook which takes a
> (non-texture) renderbuffer and wraps it in a fake texture image.
>
> We use this in Meta's BlitFramebuffer implementation to be able to blit
> from non-texture renderbuffers.  i965 also has a custom meta blit path
> for stencil, which uses the same approach.  Thus, stencil textures :)

None of which has to do with ARB_stencil_texturing being enabled as
far as mesa/main is concerned, right? IOW, why is that condition
there?

  -ilia