Revert of Fix LCD coverage regression in GrPorterDuffXPFactory (patchset #3 id:40001 of https://codereview.chromium.org/1149883004/)

Reason for revert:
Reverting this fix to revert https://codereview.chromium.org/1124373002

Original issue's description:
> Fix LCD coverage regression in GrPorterDuffXPFactory
>
> Fixes GrPorterDuffXPFactory to not use the blend table when getting
> info about the LCD coverage XP.
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/3e2d59ef36e1b9a63e524cf1b27d5f7bcfb5ff0b

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

Review URL: https://codereview.chromium.org/1153803005

2 files changed, 7 insertions, 70 deletions

diff --git a/src/gpu/effects/GrPorterDuffXferProcessor.cpp b/src/gpu/effects/GrPorterDuffXferProcessor.cpp
index bc61f499e4..de0143acea 100644
--- a/src/gpu/effects/GrPorterDuffXferProcessor.cpp
+++ b/src/gpu/effects/GrPorterDuffXferProcessor.cpp
@@ -744,16 +744,11 @@ bool GrPorterDuffXPFactory::supportsRGBCoverage(GrColor /*knownColor*/,
 void GrPorterDuffXPFactory::getInvariantOutput(const GrProcOptInfo& colorPOI,
                                                const GrProcOptInfo& coveragePOI,
                                                GrXPFactory::InvariantOutput* output) const {
-    output->fWillBlendWithDst = true;
-    output->fBlendedColorFlags = kNone_GrColorComponentFlags;
-
-    // The LCD coverage XP doesn't use the blend table, and has no invariant output.
-    if (coveragePOI.isFourChannelOutput()) {
-        return;
-    }
-
     const BlendFormula& blendFormula = get_blend_formula(fXfermode, colorPOI, coveragePOI);
+
     if (blendFormula.usesDstColor()) {
+        output->fWillBlendWithDst = true;
+        output->fBlendedColorFlags = kNone_GrColorComponentFlags;
         return;
     }
 
@@ -773,18 +768,16 @@ void GrPorterDuffXPFactory::getInvariantOutput(const GrProcOptInfo& colorPOI,
             output->fBlendedColorFlags = colorPOI.validFlags();
             return;
 
-        default: return;
+        // TODO: update if we ever use const color.
+        default:
+            output->fBlendedColorFlags = kNone_GrColorComponentFlags;
+            return;
     }
 }
 
 bool GrPorterDuffXPFactory::willReadDstColor(const GrCaps& caps,
                                              const GrProcOptInfo& colorPOI,
                                              const GrProcOptInfo& coveragePOI) const {
-    // The LCD coverage XP doesn't use the blend table, and never requires a dst read.
-    if (coveragePOI.isFourChannelOutput()) {
-        return false;
-    }
-
     // Some formulas use dual source blending, so we fall back if it is required but not supported.
     return !caps.shaderCaps()->dualSourceBlendingSupport() &&
            get_blend_formula(fXfermode, colorPOI, coveragePOI).hasSecondaryOutput();
diff --git a/tests/GrPorterDuffTest.cpp b/tests/GrPorterDuffTest.cpp
index b01277c854..79cee71333 100644
--- a/tests/GrPorterDuffTest.cpp
+++ b/tests/GrPorterDuffTest.cpp
@@ -10,7 +10,6 @@
 
 #if SK_SUPPORT_GPU
 
-#include "GrBatch.h"
 #include "GrContextFactory.h"
 #include "GrGpu.h"
 #include "GrXferProcessor.h"
@@ -24,7 +23,6 @@ static void test_alpha_opaque_with_coverage(skiatest::Reporter* reporter, const
 static void test_alpha_opaque_no_coverage(skiatest::Reporter* reporter, const GrCaps& caps);
 static void test_color_white_with_coverage(skiatest::Reporter* reporter, const GrCaps& caps);
 static void test_color_white_no_coverage(skiatest::Reporter* reporter, const GrCaps& caps);
-static void test_lcd_coverage(skiatest::Reporter* reporter, const GrCaps& caps);
 
 DEF_GPUTEST(GrPorterDuff, reporter, factory) {
     GrContext* ctx = factory->get(GrContextFactory::kNull_GLContextType);
@@ -46,7 +44,6 @@ DEF_GPUTEST(GrPorterDuff, reporter, factory) {
     test_color_white_with_coverage(reporter, caps);
     test_color_white_with_coverage(reporter, caps);
     test_color_white_no_coverage(reporter, caps);
-    test_lcd_coverage(reporter, caps);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -103,7 +100,6 @@ static void test_alpha_unknown_with_coverage(skiatest::Reporter* reporter, const
     SkASSERT(!colorPOI.isOpaque());
     SkASSERT(!colorPOI.isSolidWhite());
     SkASSERT(!covPOI.isSolidWhite());
-    SkASSERT(!covPOI.isFourChannelOutput());
 
     for (int m = 0; m <= SkXfermode::kLastCoeffMode; m++) {
         SkXfermode::Mode xfermode = static_cast<SkXfermode::Mode>(m);
@@ -294,7 +290,6 @@ static void test_alpha_unknown_no_coverage(skiatest::Reporter* reporter, const G
     SkASSERT(!colorPOI.isOpaque());
     SkASSERT(!colorPOI.isSolidWhite());
     SkASSERT(covPOI.isSolidWhite());
-    SkASSERT(!covPOI.isFourChannelOutput());
 
     for (int m = 0; m <= SkXfermode::kLastCoeffMode; m++) {
         SkXfermode::Mode xfermode = static_cast<SkXfermode::Mode>(m);
@@ -496,7 +491,6 @@ static void test_alpha_opaque_with_coverage(skiatest::Reporter* reporter, const
     SkASSERT(colorPOI.isOpaque());
     SkASSERT(!colorPOI.isSolidWhite());
     SkASSERT(!covPOI.isSolidWhite());
-    SkASSERT(!covPOI.isFourChannelOutput());
 
     for (int m = 0; m <= SkXfermode::kLastCoeffMode; m++) {
         SkXfermode::Mode xfermode = static_cast<SkXfermode::Mode>(m);
@@ -690,7 +684,6 @@ static void test_alpha_opaque_no_coverage(skiatest::Reporter* reporter, const Gr
     SkASSERT(colorPOI.isOpaque());
     SkASSERT(!colorPOI.isSolidWhite());
     SkASSERT(covPOI.isSolidWhite());
-    SkASSERT(!covPOI.isFourChannelOutput());
 
     for (int m = 0; m <= SkXfermode::kLastCoeffMode; m++) {
         SkXfermode::Mode xfermode = static_cast<SkXfermode::Mode>(m);
@@ -897,7 +890,6 @@ static void test_color_white_with_coverage(skiatest::Reporter* reporter, const G
     SkASSERT(colorPOI.isOpaque());
     SkASSERT(colorPOI.isSolidWhite());
     SkASSERT(!covPOI.isSolidWhite());
-    SkASSERT(!covPOI.isFourChannelOutput());
 
     for (int m = 0; m <= SkXfermode::kLastCoeffMode; m++) {
         SkXfermode::Mode xfermode = static_cast<SkXfermode::Mode>(m);
@@ -1090,7 +1082,6 @@ static void test_color_white_no_coverage(skiatest::Reporter* reporter, const GrC
     SkASSERT(colorPOI.isOpaque());
     SkASSERT(colorPOI.isSolidWhite());
     SkASSERT(covPOI.isSolidWhite());
-    SkASSERT(!covPOI.isFourChannelOutput());
 
     for (int m = 0; m <= SkXfermode::kLastCoeffMode; m++) {
         SkXfermode::Mode xfermode = static_cast<SkXfermode::Mode>(m);
@@ -1285,52 +1276,5 @@ static void test_color_white_no_coverage(skiatest::Reporter* reporter, const GrC
     }
 }
 
-static void test_lcd_coverage(skiatest::Reporter* reporter, const GrCaps& caps) {
-    class : public GrBatch {
-        void getInvariantOutputColor(GrInitInvariantOutput* out) const override {
-            out->setKnownFourComponents(GrColorPackRGBA(123, 45, 67, 221));
-        }
-
-        void getInvariantOutputCoverage(GrInitInvariantOutput* out) const override {
-            out->setUnknownFourComponents();
-            out->setUsingLCDCoverage();
-        }
-
-        const char* name() const override { return "Test LCD Text Batch"; }
-        void initBatchTracker(const GrPipelineInfo&) override {}
-        bool onCombineIfPossible(GrBatch*) override  { return false; }
-        void generateGeometry(GrBatchTarget*, const GrPipeline*) override {}
-
-    } testLCDCoverageBatch;
-
-    GrProcOptInfo colorPOI, covPOI;
-    colorPOI.calcColorWithBatch(&testLCDCoverageBatch, NULL, 0);
-    covPOI.calcCoverageWithBatch(&testLCDCoverageBatch, NULL, 0);
-
-    SkASSERT(kRGBA_GrColorComponentFlags == colorPOI.validFlags());
-    SkASSERT(covPOI.isFourChannelOutput());
-
-    SkAutoTUnref<GrXPFactory> xpf(GrPorterDuffXPFactory::Create(SkXfermode::kSrcOver_Mode));
-    TEST_ASSERT(!xpf->willNeedDstCopy(caps, colorPOI, covPOI));
-
-    GrXPFactory::InvariantOutput invariantOutput;
-    xpf->getInvariantOutput(colorPOI, covPOI, &invariantOutput);
-    TEST_ASSERT(invariantOutput.fWillBlendWithDst);
-    TEST_ASSERT(kNone_GrColorComponentFlags == invariantOutput.fBlendedColorFlags);
-
-    SkAutoTUnref<GrXferProcessor> xp(xpf->createXferProcessor(colorPOI, covPOI, 0, caps));
-    if (!xp) {
-        ERRORF(reporter, "Failed to create an XP with LCD coverage.");
-        return;
-    }
-
-    GrColor overrideColor;
-    xp->getOptimizations(colorPOI, covPOI, false, &overrideColor, caps);
-
-    GrXferProcessor::BlendInfo blendInfo;
-    xp->getBlendInfo(&blendInfo);
-    TEST_ASSERT(blendInfo.fWriteColor);
-}
-
 #endif