On Tue, Mar 3, 2015 at 4:31 PM, Jason Ekstrand <ja...@jlekstrand.net> wrote: > > > On Tue, Mar 3, 2015 at 1:00 PM, Ilia Mirkin <imir...@alum.mit.edu> wrote: >> >> On Tue, Mar 3, 2015 at 3:58 PM, Kenneth Graunke <kenn...@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 <ja...@jlekstrand.net> >> >> wrote: >> >> > >> >> > >> >> > On Mon, Mar 2, 2015 at 11:18 AM, Ilia Mirkin <imir...@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? > > > Well, the blit path does require it because it requires us to be able to > sample from stencil. Why does it require the internal format? That's > another question.
Right... so I totally believe you that this is necessary to not crash your driver :) I'm just questioning whether this is the right fix, or the right condition, or whatever. If I understand correctly, it will happily let me create a GL_STENCIL_INDEX texture even though that's not allowed without ARB_texture_stencil8. A driver which enables ARB_stencil_texturing (like st/mesa) will probably become confused at this and fail. Someone already added a ARB_texture_stencil8 bool to gl_extensions even though the extension is not fully-enableable... perhaps it was for this? Or perhaps there should be a driver-specific hook to the base function which enables this sort of logic. Or some other solution. -ilia _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
