[Mesa-dev] [PATCH 10/18] i965: Make a helper function for blend entry related state.

Kenneth Graunke kenneth at whitecape.org
Mon Jun 19 16:34:39 UTC 2017


On Monday, June 19, 2017 9:23:41 AM PDT Rafael Antognolli wrote:
> On Sat, Jun 17, 2017 at 10:32:44AM -0700, Kenneth Graunke wrote:
> > On Friday, June 16, 2017 4:31:23 PM PDT Rafael Antognolli wrote:
> > > Add a helper function to reuse code that fills blend entry related
> > > state, and make genX(upload_blend_state) use it. This function can later
> > > be used by gen4-5 color calc state to set the blend related bits.
> > > 
> > > Signed-off-by: Rafael Antognolli <rafael.antognolli at intel.com>
> > > ---
> > >  src/mesa/drivers/dri/i965/genX_state_upload.c | 182 ++++++++++++++------------
> > >  1 file changed, 101 insertions(+), 81 deletions(-)
> > > 
> > > diff --git a/src/mesa/drivers/dri/i965/genX_state_upload.c b/src/mesa/drivers/dri/i965/genX_state_upload.c
> > > index 5e5dc48..8e99c89 100644
> > > --- a/src/mesa/drivers/dri/i965/genX_state_upload.c
> > > +++ b/src/mesa/drivers/dri/i965/genX_state_upload.c
> > > @@ -2528,6 +2528,104 @@ fix_dual_blend_alpha_to_one(GLenum function)
> > >  #define blend_eqn(x) brw_translate_blend_equation(x)
> > >  
> > >  #if GEN_GEN >= 6
> > > +typedef struct GENX(BLEND_STATE_ENTRY) BLEND_ENTRY_GENXML;
> > > +#else
> > > +typedef struct GENX(COLOR_CALC_STATE) BLEND_ENTRY_GENXML;
> > > +#endif
> > > +
> > > +UNUSED static bool
> > > +set_blend_entry_bits(struct brw_context *brw, BLEND_ENTRY_GENXML *entry, int i,
> > > +                     bool alpha_to_one)
> > > +{
> > > +   struct gl_context *ctx = &brw->ctx;
> > > +
> > > +   /* _NEW_BUFFERS */
> > > +   const struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[i];
> > > +
> > > +   bool independent_alpha_blend = false;
> > > +
> > > +   /* Used for implementing the following bit of GL_EXT_texture_integer:
> > > +    * "Per-fragment operations that require floating-point color
> > > +    *  components, including multisample alpha operations, alpha test,
> > > +    *  blending, and dithering, have no effect when the corresponding
> > > +    *  colors are written to an integer color buffer."
> > > +    */
> > > +   const bool integer = ctx->DrawBuffer->_IntegerBuffers & (0x1 << i);
> > > +
> > > +   /* _NEW_COLOR */
> > > +   if (ctx->Color.ColorLogicOpEnabled) {
> > > +      GLenum rb_type = rb ? _mesa_get_format_datatype(rb->Format)
> > > +         : GL_UNSIGNED_NORMALIZED;
> > > +      WARN_ONCE(ctx->Color.LogicOp != GL_COPY &&
> > > +                rb_type != GL_UNSIGNED_NORMALIZED &&
> > > +                rb_type != GL_FLOAT, "Ignoring %s logic op on %s "
> > > +                "renderbuffer\n",
> > > +                _mesa_enum_to_string(ctx->Color.LogicOp),
> > > +                _mesa_enum_to_string(rb_type));
> > > +      if (GEN_GEN >= 8 || rb_type == GL_UNSIGNED_NORMALIZED) {
> > > +         entry->LogicOpEnable = true;
> > > +         entry->LogicOpFunction =
> > > +            intel_translate_logic_op(ctx->Color.LogicOp);
> > > +      }
> > > +   } else if (ctx->Color.BlendEnabled & (1 << i) && !integer &&
> > > +              !ctx->Color._AdvancedBlendMode) {
> > > +      GLenum eqRGB = ctx->Color.Blend[i].EquationRGB;
> > > +      GLenum eqA = ctx->Color.Blend[i].EquationA;
> > > +      GLenum srcRGB = ctx->Color.Blend[i].SrcRGB;
> > > +      GLenum dstRGB = ctx->Color.Blend[i].DstRGB;
> > > +      GLenum srcA = ctx->Color.Blend[i].SrcA;
> > > +      GLenum dstA = ctx->Color.Blend[i].DstA;
> > > +
> > > +      if (eqRGB == GL_MIN || eqRGB == GL_MAX)
> > > +         srcRGB = dstRGB = GL_ONE;
> > > +
> > > +      if (eqA == GL_MIN || eqA == GL_MAX)
> > > +         srcA = dstA = GL_ONE;
> > > +
> > > +      /* Due to hardware limitations, the destination may have information
> > > +       * in an alpha channel even when the format specifies no alpha
> > > +       * channel. In order to avoid getting any incorrect blending due to
> > > +       * that alpha channel, coerce the blend factors to values that will
> > > +       * not read the alpha channel, but will instead use the correct
> > > +       * implicit value for alpha.
> > > +       */
> > > +      if (rb && !_mesa_base_format_has_channel(rb->_BaseFormat,
> > > +                                               GL_TEXTURE_ALPHA_TYPE)) {
> > > +         srcRGB = brw_fix_xRGB_alpha(srcRGB);
> > > +         srcA = brw_fix_xRGB_alpha(srcA);
> > > +         dstRGB = brw_fix_xRGB_alpha(dstRGB);
> > > +         dstA = brw_fix_xRGB_alpha(dstA);
> > > +      }
> > > +
> > > +      /* From the BLEND_STATE docs, DWord 0, Bit 29 (AlphaToOne Enable):
> > > +       * "If Dual Source Blending is enabled, this bit must be disabled."
> > > +       *
> > > +       * We override SRC1_ALPHA to ONE and ONE_MINUS_SRC1_ALPHA to ZERO,
> > > +       * and leave it enabled anyway.
> > > +       */
> > > +      if (GEN_GEN >= 6 && ctx->Color.Blend[i]._UsesDualSrc && alpha_to_one) {
> > > +         srcRGB = fix_dual_blend_alpha_to_one(srcRGB);
> > > +         srcA = fix_dual_blend_alpha_to_one(srcA);
> > > +         dstRGB = fix_dual_blend_alpha_to_one(dstRGB);
> > > +         dstA = fix_dual_blend_alpha_to_one(dstA);
> > > +      }
> > > +
> > > +      entry->ColorBufferBlendEnable = true;
> > > +      entry->DestinationBlendFactor = blend_factor(dstRGB);
> > > +      entry->SourceBlendFactor = blend_factor(srcRGB);
> > > +      entry->DestinationAlphaBlendFactor = blend_factor(dstA);
> > > +      entry->SourceAlphaBlendFactor = blend_factor(srcA);
> > > +      entry->ColorBlendFunction = blend_eqn(eqRGB);
> > > +      entry->AlphaBlendFunction = blend_eqn(eqA);
> > > +
> > > +      if (srcA != srcRGB || dstA != dstRGB || eqA != eqRGB)
> > > +         independent_alpha_blend = true;
> > > +   }
> > > +
> > > +   return independent_alpha_blend;
> > > +}
> > > +
> > > +#if GEN_GEN >= 6
> > >  static void
> > >  genX(upload_blend_state)(struct brw_context *brw)
> > >  {
> > > @@ -2594,87 +2692,9 @@ genX(upload_blend_state)(struct brw_context *brw)
> > >  #else
> > >        {
> > >  #endif
> > > -
> > > -         /* _NEW_BUFFERS */
> > > -         struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[i];
> > > -
> > > -         /* Used for implementing the following bit of GL_EXT_texture_integer:
> > > -          * "Per-fragment operations that require floating-point color
> > > -          *  components, including multisample alpha operations, alpha test,
> > > -          *  blending, and dithering, have no effect when the corresponding
> > > -          *  colors are written to an integer color buffer."
> > > -          */
> > > -         bool integer = ctx->DrawBuffer->_IntegerBuffers & (0x1 << i);
> > > -
> > > -         /* _NEW_COLOR */
> > > -         if (ctx->Color.ColorLogicOpEnabled) {
> > > -            GLenum rb_type = rb ? _mesa_get_format_datatype(rb->Format)
> > > -                                : GL_UNSIGNED_NORMALIZED;
> > > -            WARN_ONCE(ctx->Color.LogicOp != GL_COPY &&
> > > -                      rb_type != GL_UNSIGNED_NORMALIZED &&
> > > -                      rb_type != GL_FLOAT, "Ignoring %s logic op on %s "
> > > -                      "renderbuffer\n",
> > > -                      _mesa_enum_to_string(ctx->Color.LogicOp),
> > > -                      _mesa_enum_to_string(rb_type));
> > > -            if (GEN_GEN >= 8 || rb_type == GL_UNSIGNED_NORMALIZED) {
> > > -               entry.LogicOpEnable = true;
> > > -               entry.LogicOpFunction =
> > > -                  intel_translate_logic_op(ctx->Color.LogicOp);
> > > -            }
> > > -         } else if (ctx->Color.BlendEnabled & (1 << i) && !integer &&
> > > -                    !ctx->Color._AdvancedBlendMode) {
> > > -            GLenum eqRGB = ctx->Color.Blend[i].EquationRGB;
> > > -            GLenum eqA = ctx->Color.Blend[i].EquationA;
> > > -            GLenum srcRGB = ctx->Color.Blend[i].SrcRGB;
> > > -            GLenum dstRGB = ctx->Color.Blend[i].DstRGB;
> > > -            GLenum srcA = ctx->Color.Blend[i].SrcA;
> > > -            GLenum dstA = ctx->Color.Blend[i].DstA;
> > > -
> > > -            if (eqRGB == GL_MIN || eqRGB == GL_MAX)
> > > -               srcRGB = dstRGB = GL_ONE;
> > > -
> > > -            if (eqA == GL_MIN || eqA == GL_MAX)
> > > -               srcA = dstA = GL_ONE;
> > > -
> > > -            /* Due to hardware limitations, the destination may have information
> > > -             * in an alpha channel even when the format specifies no alpha
> > > -             * channel. In order to avoid getting any incorrect blending due to
> > > -             * that alpha channel, coerce the blend factors to values that will
> > > -             * not read the alpha channel, but will instead use the correct
> > > -             * implicit value for alpha.
> > > -             */
> > > -            if (rb && !_mesa_base_format_has_channel(rb->_BaseFormat,
> > > -                                                     GL_TEXTURE_ALPHA_TYPE)) {
> > > -               srcRGB = brw_fix_xRGB_alpha(srcRGB);
> > > -               srcA = brw_fix_xRGB_alpha(srcA);
> > > -               dstRGB = brw_fix_xRGB_alpha(dstRGB);
> > > -               dstA = brw_fix_xRGB_alpha(dstA);
> > > -            }
> > > -
> > > -            /* From the BLEND_STATE docs, DWord 0, Bit 29 (AlphaToOne Enable):
> > > -             * "If Dual Source Blending is enabled, this bit must be disabled."
> > > -             *
> > > -             * We override SRC1_ALPHA to ONE and ONE_MINUS_SRC1_ALPHA to ZERO,
> > > -             * and leave it enabled anyway.
> > > -             */
> > > -            if (ctx->Color.Blend[i]._UsesDualSrc && blend.AlphaToOneEnable) {
> > > -               srcRGB = fix_dual_blend_alpha_to_one(srcRGB);
> > > -               srcA = fix_dual_blend_alpha_to_one(srcA);
> > > -               dstRGB = fix_dual_blend_alpha_to_one(dstRGB);
> > > -               dstA = fix_dual_blend_alpha_to_one(dstA);
> > > -            }
> > > -
> > > -            entry.ColorBufferBlendEnable = true;
> > > -            entry.DestinationBlendFactor = blend_factor(dstRGB);
> > > -            entry.SourceBlendFactor = blend_factor(srcRGB);
> > > -            entry.DestinationAlphaBlendFactor = blend_factor(dstA);
> > > -            entry.SourceAlphaBlendFactor = blend_factor(srcA);
> > > -            entry.ColorBlendFunction = blend_eqn(eqRGB);
> > > -            entry.AlphaBlendFunction = blend_eqn(eqA);
> > > -
> > > -            if (srcA != srcRGB || dstA != dstRGB || eqA != eqRGB)
> > > -               blend.IndependentAlphaBlendEnable = true;
> > > -         }
> > > +         blend.IndependentAlphaBlendEnable =
> > > +            set_blend_entry_bits(brw, &entry, i, blend.AlphaToOneEnable) ||
> > > +            blend.IndependentAlphaBlendEnable;
> > 
> > It looks like this is the only place blend.IndependentAlphaBlendEnable
> > is set, so OR'ing in the existing value (of false / 0) should be a no-op.
> > 
> >          blend.IndependentAlphaBlendEnable = 
> >             set_blend_entry_bits(brw, &entry, i, blend.AlphaToOneEnable);
> 
> It is the only place where it is set, but it's a loop. So if we set it on one
> iteration of the loop, we could later unset on the next iteration. And that's
> not the original behavior, as far as I understood.

Yikes, I missed that this is blend.* and not entry.*.  You're right of
course, nevermind that comment.

> > 
> > Patches 1-10 are:
> > Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
> > 
> > >  
> > >           /* See section 8.1.6 "Pre-Blend Color Clamping" of the
> > >            * SandyBridge PRM Volume 2 Part 1 for HW requirements.
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