Move DstCopy on gpu into the GrXferProcessor.

src/effects/SkArithmeticMode_gpu.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkArithmeticMode_gpu_DEFINED
 #define SkArithmeticMode_gpu_DEFINED
 
 #include "SkTypes.h"
 
 #if SK_SUPPORT_GPU
 
 #include "GrCoordTransform.h"
+#include "GrDrawTargetCaps.h"
 #include "GrFragmentProcessor.h"
 #include "GrTextureAccess.h"
 #include "GrTypes.h"
 #include "GrXferProcessor.h"
 
 class GrInvariantOutput;
 class GrProcOptInfo;
 class GrTexture;
 
 ///////////////////////////////////////////////////////////////////////////////
@@ skipping 39 matching lines @@
     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
     typedef GrFragmentProcessor INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 // Xfer Processor
 ///////////////////////////////////////////////////////////////////////////////
 
 class GrArithmeticXP : public GrXferProcessor {
 public:
-    static GrXferProcessor* Create(float k1, float k2, float k3, float k4, bool enforcePMColor) {
-        return SkNEW_ARGS(GrArithmeticXP, (k1, k2, k3, k4, enforcePMColor));
+    static GrXferProcessor* Create(float k1, float k2, float k3, float k4, bool enforcePMColor,
+                                         const GrDeviceCoordTexture* dstCopy,
+                                         bool willReadDstColor) {
+        return SkNEW_ARGS(GrArithmeticXP, (k1, k2, k3, k4, enforcePMColor, dstCopy,
+                                           willReadDstColor));
     }
 
     ~GrArithmeticXP() SK_OVERRIDE {};
 
     const char* name() const SK_OVERRIDE { return "Arithmetic"; }
 
-    void getGLProcessorKey(const GrGLCaps& caps, GrProcessorKeyBuilder* b) const SK_OVERRIDE;
-
     GrGLXferProcessor* createGLInstance() const SK_OVERRIDE;
 
     bool hasSecondaryOutput() const SK_OVERRIDE { return false; }
 
     GrXferProcessor::OptFlags getOptimizations(const GrProcOptInfo& colorPOI,
                                                const GrProcOptInfo& coveragePOI,
                                                bool doesStencilWrite,
                                                GrColor* overrideColor,
                                                const GrDrawTargetCaps& caps) SK_OVERRIDE;
 
     void getBlendInfo(GrXferProcessor::BlendInfo* blendInfo) const SK_OVERRIDE {
         blendInfo->fSrcBlend = kOne_GrBlendCoeff;
         blendInfo->fDstBlend = kZero_GrBlendCoeff;
         blendInfo->fBlendConstant = 0;
     }
 
     float k1() const { return fK1; }
     float k2() const { return fK2; }
     float k3() const { return fK3; }
     float k4() const { return fK4; }
     bool enforcePMColor() const { return fEnforcePMColor; }
 
 private:
-    GrArithmeticXP(float k1, float k2, float k3, float k4, bool enforcePMColor);
+    GrArithmeticXP(float k1, float k2, float k3, float k4, bool enforcePMColor,
+                   const GrDeviceCoordTexture* dstCopy, bool willReadDstColor);
+
+    void onGetGLProcessorKey(const GrGLCaps& caps, GrProcessorKeyBuilder* b) const SK_OVERRIDE;
 
     bool onIsEqual(const GrXferProcessor& xpBase) const SK_OVERRIDE {
         const GrArithmeticXP& xp = xpBase.cast<GrArithmeticXP>();
         if (fK1 != xp.fK1 ||
             fK2 != xp.fK2 ||
             fK3 != xp.fK3 ||
             fK4 != xp.fK4 ||
             fEnforcePMColor != xp.fEnforcePMColor) {
             return false;
         }
         return true;
     }
 
     float                       fK1, fK2, fK3, fK4;
     bool                        fEnforcePMColor;
 
     typedef GrXferProcessor INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 class GrArithmeticXPFactory : public GrXPFactory {
 public:
     static GrXPFactory* Create(float k1, float k2, float k3, float k4, bool enforcePMColor) {
         return SkNEW_ARGS(GrArithmeticXPFactory, (k1, k2, k3, k4, enforcePMColor));
     }
 
-    GrXferProcessor* createXferProcessor(const GrProcOptInfo& colorPOI,
-                                         const GrProcOptInfo& coveragePOI) const SK_OVERRIDE {
-        return GrArithmeticXP::Create(fK1, fK2, fK3, fK4, fEnforcePMColor);
-    }
-
     bool supportsRGBCoverage(GrColor knownColor, uint32_t knownColorFlags) const SK_OVERRIDE {
         return true;
     }
 
     bool canApplyCoverage(const GrProcOptInfo& colorPOI,
                           const GrProcOptInfo& coveragePOI) const SK_OVERRIDE {
         return true;
     }
 
     bool canTweakAlphaForCoverage() const SK_OVERRIDE {
         return false;
     }
 
     void getInvariantOutput(const GrProcOptInfo& colorPOI, const GrProcOptInfo& coveragePOI,
                             GrXPFactory::InvariantOutput*) const SK_OVERRIDE;
 
-    bool willReadDst() const SK_OVERRIDE { return true; }
-
 private:
     GrArithmeticXPFactory(float k1, float k2, float k3, float k4, bool enforcePMColor); 
 
+    GrXferProcessor* onCreateXferProcessor(const GrProcOptInfo& colorPOI,
+                                           const GrProcOptInfo& coveragePOI,
+                                           const GrDeviceCoordTexture* dstCopy) const SK_OVERRIDE {
+        return GrArithmeticXP::Create(fK1, fK2, fK3, fK4, fEnforcePMColor, dstCopy,
+                                      this->willReadDstColor());
+    }
+
+    bool willReadDstColor() const SK_OVERRIDE { return true; }
+
     bool onIsEqual(const GrXPFactory& xpfBase) const SK_OVERRIDE {
         const GrArithmeticXPFactory& xpf = xpfBase.cast<GrArithmeticXPFactory>();
         if (fK1 != xpf.fK1 ||
             fK2 != xpf.fK2 ||
             fK3 != xpf.fK3 ||
             fK4 != xpf.fK4 ||
             fEnforcePMColor != xpf.fEnforcePMColor) {
             return false;
         }
         return true;
     }
 
     GR_DECLARE_XP_FACTORY_TEST;
 
     float                       fK1, fK2, fK3, fK4;
     bool                        fEnforcePMColor;
 
     typedef GrXPFactory INHERITED;
 };
 
 #endif
 #endif