[Mesa-dev] [PATCH 1/2] meta/blit: Add stencil texturing mode save and restore

[Pohjolainen, Topi]

On Wed, May 21, 2014 at 12:51:07PM -0700, Eric Anholt wrote:
> "Pohjolainen, Topi" <topi.pohjolainen at intel.com> writes:
> 
> > On Wed, May 21, 2014 at 09:41:39PM +0300, Pohjolainen, Topi wrote:
> >> On Wed, May 21, 2014 at 09:37:30PM +0300, Pohjolainen, Topi wrote:
> >> > On Wed, May 21, 2014 at 11:29:02AM -0700, Eric Anholt wrote:
> >> > > Topi Pohjolainen <topi.pohjolainen at intel.com> writes:
> >> > > 
> >> > > > Signed-off-by: Topi Pohjolainen <topi.pohjolainen at intel.com>
> >> > > > Cc: "10.2" <mesa-stable at lists.freedesktop.org>
> >> > > > ---
> >> > > >  src/mesa/drivers/common/meta.h      |  4 ++--
> >> > > >  src/mesa/drivers/common/meta_blit.c | 15 ++++++++++++++-
> >> > > >  2 files changed, 16 insertions(+), 3 deletions(-)
> >> > > >
> >> > > > diff --git a/src/mesa/drivers/common/meta.h b/src/mesa/drivers/common/meta.h
> >> > > > index 007f104..765f8df 100644
> >> > > > --- a/src/mesa/drivers/common/meta.h
> >> > > > +++ b/src/mesa/drivers/common/meta.h
> >> > > > @@ -270,7 +270,7 @@ struct blit_state
> >> > > >  struct fb_tex_blit_state
> >> > > >  {
> >> > > >     GLint baseLevelSave, maxLevelSave;
> >> > > > -   GLuint sampler, samplerSave;
> >> > > > +   GLuint sampler, samplerSave, stencilSamplingSave;
> >> > > >     GLuint tempTex;
> >> > > >  };
> >> > > >  
> >> > > > @@ -407,7 +407,7 @@ _mesa_meta_fb_tex_blit_begin(const struct gl_context *ctx,
> >> > > >                               struct fb_tex_blit_state *blit);
> >> > > >  
> >> > > >  extern void
> >> > > > -_mesa_meta_fb_tex_blit_end(const struct gl_context *ctx, GLenum target,
> >> > > > +_mesa_meta_fb_tex_blit_end(struct gl_context *ctx, GLenum target,
> >> > > >                             struct fb_tex_blit_state *blit);
> >> > > >  
> >> > > >  extern GLboolean
> >> > > > diff --git a/src/mesa/drivers/common/meta_blit.c b/src/mesa/drivers/common/meta_blit.c
> >> > > > index e10a181..59f7e70 100644
> >> > > > --- a/src/mesa/drivers/common/meta_blit.c
> >> > > > +++ b/src/mesa/drivers/common/meta_blit.c
> >> > > > @@ -441,6 +441,7 @@ blitframebuffer_texture(struct gl_context *ctx,
> >> > > >  
> >> > > >     fb_tex_blit.baseLevelSave = texObj->BaseLevel;
> >> > > >     fb_tex_blit.maxLevelSave = texObj->MaxLevel;
> >> > > > +   fb_tex_blit.stencilSamplingSave = texObj->StencilSampling;
> >> > > >  
> >> > > >     if (glsl_version) {
> >> > > >        setup_glsl_blit_framebuffer(ctx, blit, rb, target);
> >> > > > @@ -567,7 +568,7 @@ _mesa_meta_fb_tex_blit_begin(const struct gl_context *ctx,
> >> > > >  }
> >> > > >  
> >> > > >  void
> >> > > > -_mesa_meta_fb_tex_blit_end(const struct gl_context *ctx, GLenum target,
> >> > > > +_mesa_meta_fb_tex_blit_end(struct gl_context *ctx, GLenum target,
> >> > > >                             struct fb_tex_blit_state *blit)
> >> > > >  {
> >> > > >     /* Restore texture object state, the texture binding will
> >> > > > @@ -576,6 +577,18 @@ _mesa_meta_fb_tex_blit_end(const struct gl_context *ctx, GLenum target,
> >> > > >     if (target != GL_TEXTURE_RECTANGLE_ARB) {
> >> > > >        _mesa_TexParameteri(target, GL_TEXTURE_BASE_LEVEL, blit->baseLevelSave);
> >> > > >        _mesa_TexParameteri(target, GL_TEXTURE_MAX_LEVEL, blit->maxLevelSave);
> >> > > > +
> >> > > > +      if (ctx->Extensions.ARB_stencil_texturing) {
> >> > > > +         struct gl_texture_object *texObj =
> >> > > > +            _mesa_get_current_tex_object(ctx, target);
> >> > > > +
> >> > > > +         /* One cannot use _mesa_TexParameteri() in case the stencil indexing
> >> > > > +          * wasn't modified during the blit. Hence write the saved value
> >> > > > +          * directly.
> >> > > > +          */
> >> > > 
> >> > > Can you explain that some more?  I'm uncomfortable with direct
> >> > > modification of the values instead of _mesa_TexParameteri, becuase it
> >> > > means that any other state update handling (like making sure that the
> >> > > call to Driver.TexParameter() has happened, or any necessary flushes)
> >> > > isn't getting done.
> >> > 
> >> > Glad to, if the mode was 'GL_DEPTH_COMPONENT' originally and the blit doesn't
> >> > modify it than the following issues an error:
> >> 
> >> That doesn't make sense afterall, let me check again which error I hit.
> >
> > Right, the value can originally be invalid, I have simply zero in one of the
> > runs. So it looks that proper solution is to check in addition to the
> > stencil extension being supported that the original value was valid. And only
> > then try to restore. Does that sound right?
> 
> Sounds like it's time to track down why the original value was invalid,
> and fix it.

So I take it that any normal RGBA texture should have either GL_DEPTH_COMPONENT
or GL_STENCIL_INDEX as the value for the stencil texturing mode even if
neither is really applicable?