Add Arithmetic mode xp.

src/effects/SkArithmeticMode_gpu.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkArithmeticMode_gpu.h"
 
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #include "GrFragmentProcessor.h"
 #include "GrInvariantOutput.h"
 #include "GrProcessor.h"
 #include "GrTexture.h"
 #include "gl/GrGLCaps.h"
 #include "gl/GrGLProcessor.h"
 #include "gl/GrGLProgramDataManager.h"
 #include "gl/builders/GrGLProgramBuilder.h"
 
 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 {}
 
-    virtual void setData(const GrGLProgramDataManager&, const GrProcessor&) 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";
 
-    static void GenKey(const GrProcessor&, const GrGLCaps& caps, GrProcessorKeyBuilder* b);
+        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);
+    }
+
+    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& 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;
     bool fEnforcePMColor;
 
     typedef GrGLFragmentProcessor INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 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 {
     GLArithmeticFP::GenKey(*this, caps, b);
 }
 
 GrGLFragmentProcessor* GrArithmeticFP::createGLInstance() const {
     return SkNEW_ARGS(GLArithmeticFP, (*this));
 }
 
 bool GrArithmeticFP::onIsEqual(const GrFragmentProcessor& fpBase) const {
     const GrArithmeticFP& fp = fpBase.cast<GrArithmeticFP>();
     return fK1 == fp.fK1 &&
            fK2 == fp.fK2 &&
            fK3 == fp.fK3 &&
            fK4 == fp.fK4 &&
            fEnforcePMColor == fp.fEnforcePMColor;
 }
 
 void GrArithmeticFP::onComputeInvariantOutput(GrInvariantOutput* inout) const {
     // TODO: optimize this
     inout->setToUnknown(GrInvariantOutput::kWill_ReadInput);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
-GLArithmeticFP::GLArithmeticFP(const GrProcessor&)
-   : fEnforcePMColor(true) {
-}
-
-GLArithmeticFP::~GLArithmeticFP() {
-}
-
-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();
-    }
-
-    SkASSERT(dstColor);
-    fKUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
-                                kVec4f_GrSLType, kDefault_GrSLPrecision,
-                                "k");
-    const char* kUni = builder->getUniformCStr(fKUni);
-
-    // 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");
-        }
-    }
-
-    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");
-    }
-
-    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 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 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);
-}
-
 GrFragmentProcessor* GrArithmeticFP::TestCreate(SkRandom* rand,
-                                                    GrContext*,
-                                                    const GrDrawTargetCaps&,
-                                                    GrTexture*[]) {
+                                                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();
 
-    return SkNEW_ARGS(GrArithmeticFP, (k1, k2, k3, k4, enforcePMColor, NULL));
+    return SkNEW_ARGS(GrArithmeticFP, (k1, k2, k3, k4, enforcePMColor, textures[0]));
 }
 
 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrArithmeticFP);
 
+///////////////////////////////////////////////////////////////////////////////
+// Xfer Processor
+///////////////////////////////////////////////////////////////////////////////
+
+class GLArithmeticXP : public GrGLXferProcessor {
+public:
+    GLArithmeticXP(const GrProcessor&)
+        : fEnforcePMColor(true) {
+    }
+
+    ~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);
+    }
+
+    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 GrArithmeticXP::getGLProcessorKey(const GrGLCaps& caps, GrProcessorKeyBuilder* b) const {
+    GLArithmeticXP::GenKey(*this, caps, b);
+}
+
+GrGLXferProcessor* GrArithmeticXP::createGLInstance() const {
+    return SkNEW_ARGS(GLArithmeticXP, (*this));
+}
+
+GrXferProcessor::OptFlags GrArithmeticXP::getOptimizations(const GrProcOptInfo& colorPOI,
+                                                           const GrProcOptInfo& coveragePOI,
+                                                           bool doesStencilWrite,
+                                                           GrColor* overrideColor,
+                                                           const GrDrawTargetCaps& caps) {
+   return GrXferProcessor::kNone_Opt;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+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>();
+}
+
+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