Add Arithmetic mode xp.

BUG=skia:

Review URL: https://codereview.chromium.org/837633005

5 files changed, 320 insertions, 91 deletions

diff --git a/src/effects/SkArithmeticMode.cpp b/src/effects/SkArithmeticMode.cpp
index d86f73bee4..ae18c2770e 100644
--- a/src/effects/SkArithmeticMode.cpp
+++ b/src/effects/SkArithmeticMode.cpp
@@ -31,8 +31,9 @@ public:
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkArithmeticMode_scalar)
 
 #if SK_SUPPORT_GPU
-    virtual bool asFragmentProcessor(GrFragmentProcessor**,
-                                     GrTexture* background) const SK_OVERRIDE;
+    bool asFragmentProcessor(GrFragmentProcessor**, GrTexture* background) const SK_OVERRIDE;
+
+    bool asXPFactory(GrXPFactory**) const SK_OVERRIDE;
 #endif
 
 private:
@@ -246,6 +247,17 @@ bool SkArithmeticMode_scalar::asFragmentProcessor(GrFragmentProcessor** fp,
     return true;
 }
 
+bool SkArithmeticMode_scalar::asXPFactory(GrXPFactory** xpf) const {
+    if (xpf) {
+        *xpf = GrArithmeticXPFactory::Create(SkScalarToFloat(fK[0]),
+                                             SkScalarToFloat(fK[1]),
+                                             SkScalarToFloat(fK[2]),
+                                             SkScalarToFloat(fK[3]),
+                                             fEnforcePMColor);
+    }
+    return true;
+}
+
 #endif
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkArithmeticMode)
diff --git a/src/effects/SkArithmeticMode_gpu.cpp b/src/effects/SkArithmeticMode_gpu.cpp
index 6ccd63ba74..3209fb9214 100644
--- a/src/effects/SkArithmeticMode_gpu.cpp
+++ b/src/effects/SkArithmeticMode_gpu.cpp
@@ -20,21 +20,77 @@
 
 static const bool gUseUnpremul = false;
 
+static void add_arithmetic_code(GrGLFPFragmentBuilder* fsBuilder,
+                                const char* inputColor,
+                                const char* dstColor,
+                                const char* outputColor,
+                                const char* kUni,
+                                bool enforcePMColor) {
+    // We don't try to optimize for this case at all
+    if (NULL == inputColor) {
+        fsBuilder->codeAppend("const vec4 src = vec4(1);");
+    } else {
+        fsBuilder->codeAppendf("vec4 src = %s;", inputColor);
+        if (gUseUnpremul) {
+            fsBuilder->codeAppend("src.rgb = clamp(src.rgb / src.a, 0.0, 1.0);");
+        }
+    }
+
+    fsBuilder->codeAppendf("vec4 dst = %s;", dstColor);
+    if (gUseUnpremul) {
+        fsBuilder->codeAppend("dst.rgb = clamp(dst.rgb / dst.a, 0.0, 1.0);");
+    }
+
+    fsBuilder->codeAppendf("%s = %s.x * src * dst + %s.y * src + %s.z * dst + %s.w;",
+                           outputColor, kUni, kUni, kUni, kUni);
+    fsBuilder->codeAppendf("%s = clamp(%s, 0.0, 1.0);\n", outputColor, outputColor);
+    if (gUseUnpremul) {
+        fsBuilder->codeAppendf("%s.rgb *= %s.a;", outputColor, outputColor);
+    } else if (enforcePMColor) {
+        fsBuilder->codeAppendf("%s.rgb = min(%s.rgb, %s.a);",
+                               outputColor, outputColor, outputColor);
+    }
+}
+
 class GLArithmeticFP : public GrGLFragmentProcessor {
 public:
-    GLArithmeticFP(const GrProcessor&);
-    virtual ~GLArithmeticFP();
+    GLArithmeticFP(const GrProcessor&)
+        : fEnforcePMColor(true) {
+    }
 
-    virtual void emitCode(GrGLFPBuilder*,
-                          const GrFragmentProcessor&,
-                          const char* outputColor,
-                          const char* inputColor,
-                          const TransformedCoordsArray&,
-                          const TextureSamplerArray&) SK_OVERRIDE;
+    ~GLArithmeticFP() SK_OVERRIDE {}
+
+    void emitCode(GrGLFPBuilder* builder,
+                  const GrFragmentProcessor& fp,
+                  const char* outputColor,
+                  const char* inputColor,
+                  const TransformedCoordsArray& coords,
+                  const TextureSamplerArray& samplers) SK_OVERRIDE {
+        GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
+        fsBuilder->codeAppend("vec4 bgColor = ");
+        fsBuilder->appendTextureLookup(samplers[0], coords[0].c_str(), coords[0].getType());
+        fsBuilder->codeAppendf(";");
+        const char* dstColor = "bgColor";
+
+        fKUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
+                                    kVec4f_GrSLType, kDefault_GrSLPrecision,
+                                    "k");
+        const char* kUni = builder->getUniformCStr(fKUni);
+
+        add_arithmetic_code(fsBuilder, inputColor, dstColor, outputColor, kUni, fEnforcePMColor);
+    }
 
-    virtual void setData(const GrGLProgramDataManager&, const GrProcessor&) SK_OVERRIDE;
+    void setData(const GrGLProgramDataManager& pdman, const GrProcessor& proc) SK_OVERRIDE {
+        const GrArithmeticFP& arith = proc.cast<GrArithmeticFP>();
+        pdman.set4f(fKUni, arith.k1(), arith.k2(), arith.k3(), arith.k4());
+        fEnforcePMColor = arith.enforcePMColor();
+    }
 
-    static void GenKey(const GrProcessor&, const GrGLCaps& caps, GrProcessorKeyBuilder* b);
+    static void GenKey(const GrProcessor& proc, const GrGLCaps& caps, GrProcessorKeyBuilder* b) {
+        const GrArithmeticFP& arith = proc.cast<GrArithmeticFP>();
+        uint32_t key = arith.enforcePMColor() ? 1 : 0;
+        b->add32(key);
+    }
 
 private:
     GrGLProgramDataManager::UniformHandle fKUni;
@@ -49,15 +105,14 @@ GrArithmeticFP::GrArithmeticFP(float k1, float k2, float k3, float k4,
                                bool enforcePMColor, GrTexture* background)
   : fK1(k1), fK2(k2), fK3(k3), fK4(k4), fEnforcePMColor(enforcePMColor) {
     this->initClassID<GrArithmeticFP>();
-    if (background) {
-        fBackgroundTransform.reset(kLocal_GrCoordSet, background,
-                                   GrTextureParams::kNone_FilterMode);
-        this->addCoordTransform(&fBackgroundTransform);
-        fBackgroundAccess.reset(background);
-        this->addTextureAccess(&fBackgroundAccess);
-    } else {
-        this->setWillReadDstColor();
-    }
+
+    SkASSERT(background);
+
+    fBackgroundTransform.reset(kLocal_GrCoordSet, background,
+                               GrTextureParams::kNone_FilterMode);
+    this->addCoordTransform(&fBackgroundTransform);
+    fBackgroundAccess.reset(background);
+    this->addTextureAccess(&fBackgroundAccess);
 }
 
 void GrArithmeticFP::getGLProcessorKey(const GrGLCaps& caps, GrProcessorKeyBuilder* b) const {
@@ -84,91 +139,132 @@ void GrArithmeticFP::onComputeInvariantOutput(GrInvariantOutput* inout) const {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-GLArithmeticFP::GLArithmeticFP(const GrProcessor&)
-   : fEnforcePMColor(true) {
-}
+GrFragmentProcessor* GrArithmeticFP::TestCreate(SkRandom* rand,
+                                                GrContext*,
+                                                const GrDrawTargetCaps&,
+                                                GrTexture* textures[]) {
+    float k1 = rand->nextF();
+    float k2 = rand->nextF();
+    float k3 = rand->nextF();
+    float k4 = rand->nextF();
+    bool enforcePMColor = rand->nextBool();
 
-GLArithmeticFP::~GLArithmeticFP() {
+    return SkNEW_ARGS(GrArithmeticFP, (k1, k2, k3, k4, enforcePMColor, textures[0]));
 }
 
-void GLArithmeticFP::emitCode(GrGLFPBuilder* builder,
-                              const GrFragmentProcessor& fp,
-                              const char* outputColor,
-                              const char* inputColor,
-                              const TransformedCoordsArray& coords,
-                              const TextureSamplerArray& samplers) {
-
-    GrTexture* backgroundTex = fp.cast<GrArithmeticFP>().backgroundTexture();
-    GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
-    const char* dstColor;
-    if (backgroundTex) {
-        fsBuilder->codeAppend("\t\tvec4 bgColor = ");
-        fsBuilder->appendTextureLookup(samplers[0], coords[0].c_str(), coords[0].getType());
-        fsBuilder->codeAppendf(";\n");
-        dstColor = "bgColor";
-    } else {
-        dstColor = fsBuilder->dstColor();
-    }
+GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrArithmeticFP);
 
-    SkASSERT(dstColor);
-    fKUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
-                                kVec4f_GrSLType, kDefault_GrSLPrecision,
-                                "k");
-    const char* kUni = builder->getUniformCStr(fKUni);
+///////////////////////////////////////////////////////////////////////////////
+// Xfer Processor
+///////////////////////////////////////////////////////////////////////////////
 
-    // We don't try to optimize for this case at all
-    if (NULL == inputColor) {
-        fsBuilder->codeAppendf("\t\tconst vec4 src = vec4(1);\n");
-    } else {
-        fsBuilder->codeAppendf("\t\tvec4 src = %s;\n", inputColor);
-        if (gUseUnpremul) {
-            fsBuilder->codeAppendf("\t\tsrc.rgb = clamp(src.rgb / src.a, 0.0, 1.0);\n");
-        }
+class GLArithmeticXP : public GrGLXferProcessor {
+public:
+    GLArithmeticXP(const GrProcessor&)
+        : fEnforcePMColor(true) {
     }
 
-    fsBuilder->codeAppendf("\t\tvec4 dst = %s;\n", dstColor);
-    if (gUseUnpremul) {
-        fsBuilder->codeAppendf("\t\tdst.rgb = clamp(dst.rgb / dst.a, 0.0, 1.0);\n");
+    ~GLArithmeticXP() SK_OVERRIDE {}
+
+    void emitCode(const EmitArgs& args) SK_OVERRIDE {
+        GrGLFPFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();
+
+        const char* dstColor = fsBuilder->dstColor();
+
+        fKUni = args.fPB->addUniform(GrGLProgramBuilder::kFragment_Visibility,
+                                     kVec4f_GrSLType, kDefault_GrSLPrecision,
+                                     "k");
+        const char* kUni = args.fPB->getUniformCStr(fKUni);
+
+        add_arithmetic_code(fsBuilder, args.fInputColor, dstColor, args.fOutputPrimary, kUni, 
+                            fEnforcePMColor);
+
+        fsBuilder->codeAppendf("%s = %s * %s + (vec4(1.0) - %s) * %s;",
+                               args.fOutputPrimary, args.fOutputPrimary, args.fInputCoverage,
+                               args.fInputCoverage, dstColor);
     }
 
-    fsBuilder->codeAppendf("\t\t%s = %s.x * src * dst + %s.y * src + %s.z * dst + %s.w;\n", outputColor, kUni, kUni, kUni, kUni);
-    fsBuilder->codeAppendf("\t\t%s = clamp(%s, 0.0, 1.0);\n", outputColor, outputColor);
-    if (gUseUnpremul) {
-        fsBuilder->codeAppendf("\t\t%s.rgb *= %s.a;\n", outputColor, outputColor);
-    } else if (fEnforcePMColor) {
-        fsBuilder->codeAppendf("\t\t%s.rgb = min(%s.rgb, %s.a);\n", outputColor, outputColor, outputColor);
+    void setData(const GrGLProgramDataManager& pdman,
+                 const GrXferProcessor& processor) SK_OVERRIDE {
+        const GrArithmeticXP& arith = processor.cast<GrArithmeticXP>();
+        pdman.set4f(fKUni, arith.k1(), arith.k2(), arith.k3(), arith.k4());
+        fEnforcePMColor = arith.enforcePMColor();
+    };
+
+    static void GenKey(const GrProcessor& processor, const GrGLCaps& caps,
+                       GrProcessorKeyBuilder* b) {
+        const GrArithmeticXP& arith = processor.cast<GrArithmeticXP>();
+        uint32_t key = arith.enforcePMColor() ? 1 : 0;
+        b->add32(key);
     }
+
+private:
+    GrGLProgramDataManager::UniformHandle fKUni;
+    bool fEnforcePMColor;
+
+    typedef GrGLXferProcessor INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+GrArithmeticXP::GrArithmeticXP(float k1, float k2, float k3, float k4, bool enforcePMColor)
+    : fK1(k1)
+    , fK2(k2)
+    , fK3(k3)
+    , fK4(k4)
+    , fEnforcePMColor(enforcePMColor) {
+    this->initClassID<GrPorterDuffXferProcessor>();
+    this->setWillReadDstColor();
 }
 
-void GLArithmeticFP::setData(const GrGLProgramDataManager& pdman, const GrProcessor& processor) {
-    const GrArithmeticFP& arith = processor.cast<GrArithmeticFP>();
-    pdman.set4f(fKUni, arith.k1(), arith.k2(), arith.k3(), arith.k4());
-    fEnforcePMColor = arith.enforcePMColor();
+void GrArithmeticXP::getGLProcessorKey(const GrGLCaps& caps, GrProcessorKeyBuilder* b) const {
+    GLArithmeticXP::GenKey(*this, caps, b);
 }
 
-void GLArithmeticFP::GenKey(const GrProcessor& processor, const GrGLCaps&,
-                            GrProcessorKeyBuilder* b) {
-    const GrArithmeticFP& arith = processor.cast<GrArithmeticFP>();
-    uint32_t key = arith.enforcePMColor() ? 1 : 0;
-    if (arith.backgroundTexture()) {
-        key |= 2;
-    }
-    b->add32(key);
+GrGLXferProcessor* GrArithmeticXP::createGLInstance() const {
+    return SkNEW_ARGS(GLArithmeticXP, (*this));
 }
 
-GrFragmentProcessor* GrArithmeticFP::TestCreate(SkRandom* rand,
-                                                    GrContext*,
-                                                    const GrDrawTargetCaps&,
-                                                    GrTexture*[]) {
-    float k1 = rand->nextF();
-    float k2 = rand->nextF();
-    float k3 = rand->nextF();
-    float k4 = rand->nextF();
-    bool enforcePMColor = rand->nextBool();
+GrXferProcessor::OptFlags GrArithmeticXP::getOptimizations(const GrProcOptInfo& colorPOI,
+                                                           const GrProcOptInfo& coveragePOI,
+                                                           bool doesStencilWrite,
+                                                           GrColor* overrideColor,
+                                                           const GrDrawTargetCaps& caps) {
+   return GrXferProcessor::kNone_Opt;
+}
 
-    return SkNEW_ARGS(GrArithmeticFP, (k1, k2, k3, k4, enforcePMColor, NULL));
+///////////////////////////////////////////////////////////////////////////////
+
+GrArithmeticXPFactory::GrArithmeticXPFactory(float k1, float k2, float k3, float k4,
+                                             bool enforcePMColor) 
+    : fK1(k1), fK2(k2), fK3(k3), fK4(k4), fEnforcePMColor(enforcePMColor) {
+        this->initClassID<GrArithmeticXPFactory>();
 }
 
-GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrArithmeticFP);
+void GrArithmeticXPFactory::getInvariantOutput(const GrProcOptInfo& colorPOI,
+                                               const GrProcOptInfo& coveragePOI,
+                                               GrXPFactory::InvariantOutput* output) const {
+    output->fWillBlendWithDst = true;
+
+    // TODO: We could try to optimize this more. For example if we have solid coverage and fK1 and
+    // fK3 are zero, then we won't be blending the color with dst at all so we can know what the
+    // output color is (up to the valid color components passed in).
+    output->fBlendedColorFlags = 0;
+}
+
+GR_DEFINE_XP_FACTORY_TEST(GrArithmeticXPFactory);
+
+GrXPFactory* GrArithmeticXPFactory::TestCreate(SkRandom* random,
+                                               GrContext*,
+                                               const GrDrawTargetCaps&,
+                                               GrTexture*[]) {
+    float k1 = random->nextF();
+    float k2 = random->nextF();
+    float k3 = random->nextF();
+    float k4 = random->nextF();
+    bool enforcePMColor = random->nextBool();
+
+    return GrArithmeticXPFactory::Create(k1, k2, k3, k4, enforcePMColor);
+}
 
 #endif
diff --git a/src/effects/SkArithmeticMode_gpu.h b/src/effects/SkArithmeticMode_gpu.h
index 84b839d2cb..17116c29be 100644
--- a/src/effects/SkArithmeticMode_gpu.h
+++ b/src/effects/SkArithmeticMode_gpu.h
@@ -13,8 +13,11 @@
 #include "GrCoordTransform.h"
 #include "GrFragmentProcessor.h"
 #include "GrTextureAccess.h"
+#include "GrTypes.h"
+#include "GrXferProcessor.h"
 
 class GrInvariantOutput;
+class GrProcOptInfo;
 class GrTexture;
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -38,8 +41,6 @@ public:
 
     GrGLFragmentProcessor* createGLInstance() const SK_OVERRIDE;
 
-    GrTexture* backgroundTexture() const { return fBackgroundAccess.getTexture(); }
-
     float k1() const { return fK1; }
     float k2() const { return fK2; }
     float k3() const { return fK3; }
@@ -63,5 +64,121 @@ private:
     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));
+    }
+
+    ~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);
+
+    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 GrProcOptInfo& colorPOI,
+                     const GrProcOptInfo& coveragePOI) const SK_OVERRIDE {
+        return true;
+    }
+
+private:
+    GrArithmeticXPFactory(float k1, float k2, float k3, float k4, bool enforcePMColor); 
+
+    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
diff --git a/src/gpu/GrOptDrawState.cpp b/src/gpu/GrOptDrawState.cpp
index a30121256d..742ffade12 100644
--- a/src/gpu/GrOptDrawState.cpp
+++ b/src/gpu/GrOptDrawState.cpp
@@ -145,6 +145,10 @@ void GrOptDrawState::adjustProgramFromOptimizations(const GrDrawState& ds,
             fDescInfo.fReadsFragPosition = true;
         }
     }
+
+    if (fXferProcessor->willReadDstColor()) {
+        fDescInfo.fReadsDst = true;
+    }
 }
 
 void GrOptDrawState::finalize(GrGpu* gpu) {
diff --git a/src/gpu/GrProcessor.cpp b/src/gpu/GrProcessor.cpp
index 75245f34ae..44c8bf1957 100644
--- a/src/gpu/GrProcessor.cpp
+++ b/src/gpu/GrProcessor.cpp
@@ -52,7 +52,7 @@ GrProcessorTestFactory<GrGeometryProcessor>::GetFactories() {
  */
 static const int kFPFactoryCount = 37;
 static const int kGPFactoryCount = 14;
-static const int kXPFactoryCount = 3;
+static const int kXPFactoryCount = 4;
 
 template<>
 void GrProcessorTestFactory<GrFragmentProcessor>::VerifyFactoryCount() {