Add Xfer Processor for GrCustomXfermodes

src/gpu/effects/GrCustomXfermodePriv.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 GrCustomXfermodePriv_DEFINED
 #define GrCustomXfermodePriv_DEFINED
 
 #include "GrCoordTransform.h"
 #include "GrFragmentProcessor.h"
 #include "GrTextureAccess.h"
+#include "GrXferProcessor.h"
 #include "SkXfermode.h"
 
 class GrGLCaps;
 class GrGLFragmentProcessor;
 class GrInvariantOutput;
 class GrProcessorKeyBuilder;
 class GrTexture;
 
 ///////////////////////////////////////////////////////////////////////////////
 // Fragment Processor
@@ skipping 19 matching lines @@
 
     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
 
     SkXfermode::Mode fMode;
     GrCoordTransform fBackgroundTransform;
     GrTextureAccess  fBackgroundAccess;
 
     typedef GrFragmentProcessor INHERITED;
 };
 
+///////////////////////////////////////////////////////////////////////////////
+// Xfer Processor
+///////////////////////////////////////////////////////////////////////////////
+
+class GrCustomXP : public GrXferProcessor {
+public:
+    static GrXferProcessor* Create(SkXfermode::Mode mode) {
+        if (!GrCustomXfermode::IsSupportedMode(mode)) {
+            return NULL;
+        } else {
+            return SkNEW_ARGS(GrCustomXP, (mode));
+        }
+    }
+
+    ~GrCustomXP() SK_OVERRIDE {};
+
+    const char* name() const SK_OVERRIDE { return "Custom Xfermode"; }
+
+    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;
+    }
+
+    SkXfermode::Mode mode() const { return fMode; }
+
+private:
+    GrCustomXP(SkXfermode::Mode mode);
+
+    bool onIsEqual(const GrXferProcessor& xpBase) const SK_OVERRIDE;
+
+    SkXfermode::Mode fMode;
+
+    typedef GrXferProcessor INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+class GrCustomXPFactory : public GrXPFactory {
+public:
+    GrCustomXPFactory(SkXfermode::Mode mode); 
+
+    GrXferProcessor* createXferProcessor(const GrProcOptInfo& colorPOI,
+                                         const GrProcOptInfo& coveragePOI) const SK_OVERRIDE {
+        return GrCustomXP::Create(fMode);
+    }
+
+    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 GrProcOptInfo& colorPOI,
+                     const GrProcOptInfo& coveragePOI) const SK_OVERRIDE {
+        return true;
+    }
+
+private:
+    bool onIsEqual(const GrXPFactory& xpfBase) const SK_OVERRIDE {
+        const GrCustomXPFactory& xpf = xpfBase.cast<GrCustomXPFactory>();
+        return fMode == xpf.fMode;
+    }
+
+    GR_DECLARE_XP_FACTORY_TEST;
+
+    SkXfermode::Mode fMode;
+
+    typedef GrXPFactory INHERITED;
+};
 #endif