added support for PLS path rendering

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 730 matching lines @@
         return nullptr;
     }
     return SkRef(gFactories[xfermode]);
 }
 
 GrXferProcessor*
 GrPorterDuffXPFactory::onCreateXferProcessor(const GrCaps& caps,
                                              const GrPipelineOptimizations& optimizations,
                                              bool hasMixedSamples,
                                              const DstTexture* dstTexture) const {
+    if (optimizations.fOverrides.fUsePLSDstRead) {
+        return new ShaderPDXferProcessor(dstTexture, hasMixedSamples, fXfermode);
+    }
     BlendFormula blendFormula;
     if (optimizations.fCoveragePOI.isFourChannelOutput()) {
         if (SkXfermode::kSrcOver_Mode == fXfermode &&
             kRGBA_GrColorComponentFlags == optimizations.fColorPOI.validFlags() &&
             !caps.shaderCaps()->dualSourceBlendingSupport() &&
             !caps.shaderCaps()->dstReadInShaderSupport()) {
             // If we don't have dual source blending or in shader dst reads, we fall back to this
             // trick for rendering SrcOver LCD text instead of doing a dst copy.
             SkASSERT(!dstTexture || !dstTexture->texture());
             return PDLCDXferProcessor::Create(fXfermode, optimizations.fColorPOI);
@@ skipping 39 matching lines @@
 
         default:
             blendedColor->fKnownColorFlags = kNone_GrColorComponentFlags;
             return;
     }
 }
 
 bool GrPorterDuffXPFactory::willReadDstColor(const GrCaps& caps,
                                              const GrPipelineOptimizations& optimizations,
                                              bool hasMixedSamples) const {
+    if (INHERITED::willReadDstColor(caps, optimizations, hasMixedSamples)) {
+        return true;
+    }
     if (caps.shaderCaps()->dualSourceBlendingSupport()) {
         return false;
     }
     
     // When we have four channel coverage we always need to read the dst in order to correctly
     // blend. The one exception is when we are using srcover mode and we know the input color into
     // the XP.
     if (optimizations.fCoveragePOI.isFourChannelOutput()) {
         if (SkXfermode::kSrcOver_Mode == fXfermode &&
             kRGBA_GrColorComponentFlags == optimizations.fColorPOI.validFlags() &&
@@ skipping 36 matching lines @@
                                                              kISA_GrBlendCoeff);
     static PorterDuffXferProcessor gSrcOverXP(gSrcOverBlendFormula);
     return gSrcOverXP;
 }
 
 GrXferProcessor* GrPorterDuffXPFactory::CreateSrcOverXferProcessor(
         const GrCaps& caps,
         const GrPipelineOptimizations& optimizations,
         bool hasMixedSamples,
         const GrXferProcessor::DstTexture* dstTexture) {
+    if (optimizations.fOverrides.fUsePLSDstRead) {
+        return new ShaderPDXferProcessor(dstTexture, hasMixedSamples, SkXfermode::kSrcOver_Mode);
+    }
     if (!optimizations.fCoveragePOI.isFourChannelOutput() &&
         !(optimizations.fCoveragePOI.isSolidWhite() &&
           !hasMixedSamples &&
           optimizations.fColorPOI.isOpaque())) {
         // We return nullptr here, which our caller interprets as meaning "use SimpleSrcOverXP".
         // We don't simply return the address of that XP here because our caller would have to unref
         // it and since it is a global object and GrProgramElement's ref-cnting system is not thread
         // safe.
         return nullptr;
     }
@@ skipping 41 matching lines @@
         }
         return get_lcd_blend_formula(optimizations.fCoveragePOI, 
                                      SkXfermode::kSrcOver_Mode).hasSecondaryOutput();
     }
     // We fallback on the shader XP when the blend formula would use dual source blending but we
     // don't have support for it.
     return get_blend_formula(optimizations.fColorPOI, optimizations.fCoveragePOI,
                              hasMixedSamples, SkXfermode::kSrcOver_Mode).hasSecondaryOutput();
 }