Revert of Implement Porter Duff XP with a blend table (patchset #12 id:220001 of https://codereview.chromium.org/1124373002/)

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/+/9a70920db22b6309c671f8e5d519bb95570e4414

TBR=egdaniel@google.com,bsalomon@google.com,cdalton@nvidia.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1153993002

1 files changed, 0 insertions, 191 deletions

diff --git a/gm/aaxfermodes.cpp b/gm/aaxfermodes.cpp
deleted file mode 100644
index 30b34a4d53..0000000000
--- a/gm/aaxfermodes.cpp
+++ /dev/null
@@ -1,191 +0,0 @@
-
-/*
- * Copyright 2015 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-#include "gm.h"
-#include "SkArithmeticMode.h"
-#include "SkShader.h"
-#include "SkXfermode.h"
-
-enum {
-    kXfermodeCount = SkXfermode::kLastMode + 2, // All xfermodes plus arithmetic mode.
-    kShapeSize = 22,
-    kShapeSpacing = 36,
-    kShapeTypeSpacing = 4 * kShapeSpacing/3,
-    kPaintSpacing = 2 * kShapeSpacing,
-    kPadding = (kPaintSpacing - kShapeSpacing) / 2,
-
-    kPaintWidth = 3*kShapeSpacing + 2*kShapeTypeSpacing + kShapeSize,
-    kPaintPadding = kPaintSpacing - kShapeSize,
-};
-
-static const SkColor kBGColor = SkColorSetARGB(200, 210, 184, 135);
-
-static const SkColor kShapeColors[3] = {
-    SkColorSetARGB(130, 255, 0, 128),   // input color unknown
-    SkColorSetARGB(255, 0, 255, 255),   // input color opaque
-    SkColorSetARGB(255, 255, 255, 255)  // input solid white
-};
-
-enum Shape {
-    kSquare_Shape,
-    kDiamond_Shape,
-    kOval_Shape,
-
-    kLast_Shape = kOval_Shape
-};
-
-namespace skiagm {
-
-static void draw_shape(SkCanvas* canvas, Shape shape, const SkColor color, size_t xfermodeIdx);
-
-/**
- * Verifies AA works properly on all Xfermodes, including arithmetic, with various color invariants.
- */
-class AAXfermodesGM : public GM {
-public:
-    AAXfermodesGM() {}
-
-protected:
-    SkString onShortName() override {
-        return SkString("aaxfermodes");
-    }
-
-    SkISize onISize() override {
-        return SkISize::Make(3*kPaintWidth + 2*kPaintPadding + 2*kPadding,
-                             (2 + SkXfermode::kLastCoeffMode) * kShapeSpacing + 2*kPadding);
-    }
-
-    void onDraw(SkCanvas* canvas) override {
-        sk_tool_utils::draw_checkerboard(canvas, 0xffffffff, 0xffc0c0c0, 10);
-
-        canvas->saveLayer(NULL, NULL);
-        canvas->drawColor(kBGColor, SkXfermode::kSrc_Mode);
-
-        canvas->translate(kPadding + kShapeSize/2, kPadding + kShapeSpacing + kShapeSize/2);
-
-        for (size_t colorIdx = 0; colorIdx < SK_ARRAY_COUNT(kShapeColors); colorIdx++) {
-            SkColor color = kShapeColors[colorIdx];
-
-            for (size_t shapeIdx = 0; shapeIdx <= kLast_Shape; shapeIdx++) {
-                Shape shape = static_cast<Shape>(shapeIdx);
-                canvas->save();
-
-                for (size_t xfermodeIdx = 0; xfermodeIdx < kXfermodeCount; xfermodeIdx++) {
-                    draw_shape(canvas, shape, color, xfermodeIdx);
-
-                    if (xfermodeIdx == SkXfermode::kLastCoeffMode) {
-                        // New column.
-                        canvas->restore();
-                        canvas->translate(kShapeSpacing, 0);
-                        canvas->save();
-                    } else {
-                        canvas->translate(0, kShapeSpacing);
-                    }
-                }
-
-                canvas->restore();
-
-                if (shape != kLast_Shape) {
-                    canvas->translate(kShapeTypeSpacing, 0);
-                } else {
-                    canvas->translate(kPaintSpacing, 0);
-                }
-            }
-        }
-
-        canvas->restore();
-
-        SkPaint textPaint;
-        textPaint.setAntiAlias(true);
-        sk_tool_utils::set_portable_typeface(&textPaint);
-        textPaint.setTextAlign(SkPaint::kCenter_Align);
-        textPaint.setFakeBoldText(true);
-        textPaint.setTextSize(21 * kShapeSize/32);
-
-        canvas->translate(kPadding + kPaintWidth/2,
-                          kPadding + kShapeSize/2 + textPaint.getTextSize()/4);
-        canvas->drawText("input color unknown", sizeof("input color unknown") - 1, 0, 0, textPaint);
-
-        canvas->translate(kPaintWidth + kPaintPadding, 0);
-        canvas->drawText("input color opaque", sizeof("input color opaque") - 1, 0, 0, textPaint);
-
-        canvas->translate(kPaintWidth + kPaintPadding, 0);
-        canvas->drawText("input solid white", sizeof("input solid white") - 1, 0, 0, textPaint);
-    }
-
-private:
-    typedef GM INHERITED;
-};
-
-static void draw_shape(SkCanvas* canvas, Shape shape, const SkColor color, size_t xfermodeIdx) {
-    SkPaint shapePaint;
-    shapePaint.setAntiAlias(kSquare_Shape != shape);
-    shapePaint.setColor(color);
-
-    SkAutoTUnref<SkXfermode> xfermode;
-    if (xfermodeIdx <= SkXfermode::kLastMode) {
-        SkXfermode::Mode mode = static_cast<SkXfermode::Mode>(xfermodeIdx);
-        xfermode.reset(SkXfermode::Create(mode));
-    } else {
-        xfermode.reset(SkArithmeticMode::Create(+1.0f, +0.25f, -0.5f, +0.1f));
-    }
-    shapePaint.setXfermode(xfermode);
-
-    if (xfermodeIdx == SkXfermode::kPlus_Mode) {
-        // Check for overflow and dim the src and dst colors if we need to, otherwise we might get
-        // confusing AA artifacts.
-        int maxSum = SkTMax(SkTMax(SkColorGetA(kBGColor) + SkColorGetA(color),
-                                   SkColorGetR(kBGColor) + SkColorGetR(color)),
-                            SkTMax(SkColorGetG(kBGColor) + SkColorGetG(color),
-                                   SkColorGetB(kBGColor) + SkColorGetB(color)));
-
-        if (maxSum > 255) {
-            SkPaint dimPaint;
-            dimPaint.setARGB(255 * 255 / maxSum, 0, 0, 0);
-            dimPaint.setAntiAlias(false);
-            dimPaint.setXfermode(SkXfermode::Create(SkXfermode::kDstIn_Mode));
-            canvas->drawRectCoords(-kShapeSpacing/2, -kShapeSpacing/2,
-                                   kShapeSpacing/2, kShapeSpacing/2, dimPaint);
-
-            shapePaint.setAlpha(255 * shapePaint.getAlpha() / maxSum);
-        }
-    }
-
-    switch (shape) {
-        case kSquare_Shape:
-            canvas->drawRectCoords(-kShapeSize/2, -kShapeSize/2, kShapeSize/2, kShapeSize/2,
-                                   shapePaint);
-            break;
-
-        case kDiamond_Shape:
-            canvas->save();
-            canvas->rotate(45);
-            canvas->drawRectCoords(-kShapeSize/2, -kShapeSize/2, kShapeSize/2, kShapeSize/2,
-                                   shapePaint);
-            canvas->restore();
-            break;
-
-        case kOval_Shape:
-            canvas->save();
-            canvas->rotate(static_cast<SkScalar>((511 * xfermodeIdx + 257) % 360));
-            canvas->drawArc(SkRect::MakeLTRB(-kShapeSize/2, -1.4f * kShapeSize/2,
-                                             kShapeSize/2, 1.4f * kShapeSize/2),
-                            0, 360, true, shapePaint);
-            canvas->restore();
-            break;
-
-        default:
-            SkFAIL("Invalid shape.");
-    }
-}
-
-//////////////////////////////////////////////////////////////////////////////
-
-static GM* MyFactory(void*) { return new AAXfermodesGM; }
-static GMRegistry reg(MyFactory);
-
-}