Reason for revert:
Blocking DEPS roll into Chromium. Crashing virtual/gpu/fast/canvas/canvas-composite-*.html tests with the assert
../../third_party/skia/src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp:281: failed assertion "k110_GrGLSLGeneration != gpu->glslGeneration() || fOutputs.empty()"
Original issue's description:
> Implement Porter Duff XP with a blend table
>
> Removes the runtime logic used by PorterDuffXferProcessor to decide
> blend coeffs and shader outputs, and instead uses a compile-time
> constant table of pre-selected blend formulas.
>
> Introduces a new blend strategy for srcCoeff=0 that can apply coverage
> with a reverse subtract blend equation instead of dual source
> blending.
>
> Adds new macros in GrBlend.h to analyze blend formulas both runtime.
>
> Removes kSetCoverageDrawing_OptFlag and GrSimplifyBlend as they are no
> longer used.
>
> Adds a GM that verifies all xfermodes, including arithmetic, with the
> color/coverage invariants used by Porter Duff.
>
> Adds a unit test that verifies each Porter Duff formula with every
> color/coverage invariant.
>
> Major changes:
>
> * Uses a reverse subtract blend equation for coverage when srcCoeff=0
> (clear, dst-out [Sa=1], dst-in, modulate). Platforms that don't
> support dual source blending no longer require a dst copy for
> dst-in and modulate.
>
> * Sets BlendInfo::fWriteColor to false when the blend does not modify
> the dst. GrGLGpu will now use glColorMask instead of blending for
> these modes (dst, dst-in [Sa=1], modulate ignored for [Sc=1]).
>
> * Converts all SA blend coeffs to One for opaque inputs, and ISA to
> Zero if there is also no coverage. (We keep ISA around when there
> is coverage because we use it to tweak alpha for coverage.)
>
> * Abandons solid white optimizations for the sake of simplicity
> (screen was the only mode that previous had solid white opts).
>
> Minor differences:
>
> * Inconsequential differences in opt flags (e.g. we now return
> kCanTweakAlphaForCoverage_OptFlag even when there is no coverage).
>
> * Src coeffs when the shader outputs 0.
>
> * IS2C vs IS2A when the secondary output is scalar.
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/9a70920db22b6309c671f8e5d519bb95570e4414TBR=egdaniel@google.com,bsalomon@google.com,cdalton@nvidia.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:
Review URL: https://codereview.chromium.org/1153993002
Removes the runtime logic used by PorterDuffXferProcessor to decide
blend coeffs and shader outputs, and instead uses a compile-time
constant table of pre-selected blend formulas.
Introduces a new blend strategy for srcCoeff=0 that can apply coverage
with a reverse subtract blend equation instead of dual source
blending.
Adds new macros in GrBlend.h to analyze blend formulas both runtime.
Removes kSetCoverageDrawing_OptFlag and GrSimplifyBlend as they are no
longer used.
Adds a GM that verifies all xfermodes, including arithmetic, with the
color/coverage invariants used by Porter Duff.
Adds a unit test that verifies each Porter Duff formula with every
color/coverage invariant.
Major changes:
* Uses a reverse subtract blend equation for coverage when srcCoeff=0
(clear, dst-out [Sa=1], dst-in, modulate). Platforms that don't
support dual source blending no longer require a dst copy for
dst-in and modulate.
* Sets BlendInfo::fWriteColor to false when the blend does not modify
the dst. GrGLGpu will now use glColorMask instead of blending for
these modes (dst, dst-in [Sa=1], modulate ignored for [Sc=1]).
* Converts all SA blend coeffs to One for opaque inputs, and ISA to
Zero if there is also no coverage. (We keep ISA around when there
is coverage because we use it to tweak alpha for coverage.)
* Abandons solid white optimizations for the sake of simplicity
(screen was the only mode that previous had solid white opts).
Minor differences:
* Inconsequential differences in opt flags (e.g. we now return
kCanTweakAlphaForCoverage_OptFlag even when there is no coverage).
* Src coeffs when the shader outputs 0.
* IS2C vs IS2A when the secondary output is scalar.
BUG=skia:
Review URL: https://codereview.chromium.org/1124373002
In addition, NVPR makes this very complicated, and I haven't quite figured out a good way to handle it, so for now color and coverage DO live on optstate, but I will figure out some way to refactor that in future CLs.
BUG=skia:
Review URL: https://codereview.chromium.org/783763002
This allows us to create distance field textures with better precision,
which may help text quality.
BUG=skia:3103
Review URL: https://codereview.chromium.org/762923003
This CL cleans up the existing violations and enables the
build time check to ensure that we don't regress.
The motiviation behind this change is to allow clients who include
our headers to be able to build with this warning enabled.
Review URL: https://codereview.chromium.org/726923002
