Only discard for XP dstCopies if we have a coverage value.

src/gpu/effects/GrPorterDuffXferProcessor.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "effects/GrPorterDuffXferProcessor.h"
 
 #include "GrBlend.h"
@@ skipping 66 matching lines @@
         // Writes coverage * (1 - colorRGBA) as the secondary output. Only set if dual source
         // blending is supported and primary output is kModulate.
         kCoverageISC_SecondaryOutputType,
 
         kSecondaryOutputTypeCnt,
     };
 
     PrimaryOutputType primaryOutputType() const { return fPrimaryOutputType; }
     SecondaryOutputType secondaryOutputType() const { return fSecondaryOutputType; }
 
-    GrXferProcessor::OptFlags getOptimizations(const GrProcOptInfo& colorPOI,
-                                               const GrProcOptInfo& coveragePOI,
-                                               bool doesStencilWrite,
-                                               GrColor* overrideColor,
-                                               const GrDrawTargetCaps& caps) override;
-
     GrBlendCoeff getSrcBlend() const { return fSrcBlend; }
     GrBlendCoeff getDstBlend() const { return fDstBlend; }
 
 private:
     PorterDuffXferProcessor(GrBlendCoeff srcBlend, GrBlendCoeff dstBlend, GrColor constant,
                             const GrDeviceCoordTexture* dstCopy, bool willReadDstColor);
 
+    GrXferProcessor::OptFlags onGetOptimizations(const GrProcOptInfo& colorPOI,
+                                                 const GrProcOptInfo& coveragePOI,
+                                                 bool doesStencilWrite,
+                                                 GrColor* overrideColor,
+                                                 const GrDrawTargetCaps& caps) override;
+
     void onGetGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override;
 
     void onGetBlendInfo(GrXferProcessor::BlendInfo* blendInfo) const override {
         if (!this->willReadDstColor()) {
             blendInfo->fSrcBlend = fSrcBlend;
             blendInfo->fDstBlend = fDstBlend;
         } else {
             blendInfo->fSrcBlend = kOne_GrBlendCoeff;
             blendInfo->fDstBlend = kZero_GrBlendCoeff;
         }
@@ skipping 184 matching lines @@
 void PorterDuffXferProcessor::onGetGLProcessorKey(const GrGLSLCaps& caps,
                                                   GrProcessorKeyBuilder* b) const {
     GLPorterDuffXferProcessor::GenKey(*this, caps, b);
 }
 
 GrGLXferProcessor* PorterDuffXferProcessor::createGLInstance() const {
     return SkNEW_ARGS(GLPorterDuffXferProcessor, (*this));
 }
 
 GrXferProcessor::OptFlags
-PorterDuffXferProcessor::getOptimizations(const GrProcOptInfo& colorPOI,
-                                          const GrProcOptInfo& coveragePOI,
-                                          bool doesStencilWrite,
-                                          GrColor* overrideColor,
-                                          const GrDrawTargetCaps& caps) {
+PorterDuffXferProcessor::onGetOptimizations(const GrProcOptInfo& colorPOI,
+                                            const GrProcOptInfo& coveragePOI,
+                                            bool doesStencilWrite,
+                                            GrColor* overrideColor,
+                                            const GrDrawTargetCaps& caps) {
     GrXferProcessor::OptFlags optFlags;
     // Optimizations when doing RGB Coverage
     if (coveragePOI.isFourChannelOutput()) {
         // We want to force our primary output to be alpha * Coverage, where alpha is the alpha
         // value of the blend the constant. We should already have valid blend coeff's if we are at
         // a point where we have RGB coverage. We don't need any color stages since the known color
         // output is already baked into the blendConstant.
         uint8_t alpha = GrColorUnpackA(fBlendConstant);
         *overrideColor = GrColorPackRGBA(alpha, alpha, alpha, alpha);
         optFlags = GrXferProcessor::kOverrideColor_OptFlag;
@@ skipping 379 matching lines @@
 GR_DEFINE_XP_FACTORY_TEST(GrPorterDuffXPFactory);
 
 GrXPFactory* GrPorterDuffXPFactory::TestCreate(SkRandom* random,
                                                GrContext*,
                                                const GrDrawTargetCaps&,
                                                GrTexture*[]) {
     SkXfermode::Mode mode = SkXfermode::Mode(random->nextULessThan(SkXfermode::kLastCoeffMode));
     return GrPorterDuffXPFactory::Create(mode);
 }