Pull out Effect Shaders in GPU Path Renderer

src/gpu/effects/GrBezierEffect.cpp

Index: src/gpu/effects/GrBezierEffect.cpp
diff --git a/src/gpu/effects/GrBezierEffect.cpp b/src/gpu/effects/GrBezierEffect.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..c5a12c9849fec3c2fa573fc235d42c7c430057a5
--- /dev/null
+++ b/src/gpu/effects/GrBezierEffect.cpp
@@ -0,0 +1,417 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrBezierEffect.h"
+
+#include "gl/GrGLEffect.h"
+#include "gl/GrGLSL.h"
+#include "GrTBackendEffectFactory.h"
+
+class GrGLConicEffect : public GrGLEffect {
+public:
+    GrGLConicEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
+
+    virtual void emitCode(GrGLShaderBuilder* builder,
+                          const GrDrawEffect& drawEffect,
+                          EffectKey key,
+                          const char* outputColor,
+                          const char* inputColor,
+                          const TextureSamplerArray&) SK_OVERRIDE;
+
+    static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
+
+    virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {}
+
+private:
+    GrBezierEdgeType fEdgeType;
+
+    typedef GrGLEffect INHERITED;
+};
+    
+GrGLConicEffect::GrGLConicEffect(const GrBackendEffectFactory& factory,
+                                 const GrDrawEffect& drawEffect)
+    : INHERITED (factory) {
+    const GrConicEffect& ce = drawEffect.castEffect<GrConicEffect>();
+    fEdgeType = ce.getEdgeType();
+}
+
+void GrGLConicEffect::emitCode(GrGLShaderBuilder* builder,
+                               const GrDrawEffect& drawEffect,
+                               EffectKey key,
+                               const char* outputColor,
+                               const char* inputColor,
+                               const TextureSamplerArray& samplers) {
+    const char *vsName, *fsName;
+
+    builder->addVarying(kVec4f_GrSLType, "ConicCoeffs",
+                        &vsName, &fsName);
+    const SkString* attr0Name =
+        builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0]);
+    builder->vsCodeAppendf("\t%s = %s;\n", vsName, attr0Name->c_str());
+
+    builder->fsCodeAppend("\t\tfloat edgeAlpha;\n");
+
+    switch (fEdgeType) {
+        case kHairAA_GrBezierEdgeType: {
+            SkAssertResult(builder->enableFeature(
+                    GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
+            builder->fsCodeAppendf("\t\tvec3 dklmdx = dFdx(%s.xyz);\n", fsName);
+            builder->fsCodeAppendf("\t\tvec3 dklmdy = dFdy(%s.xyz);\n", fsName);
+            builder->fsCodeAppendf("\t\tfloat dfdx =\n"
+                                   "\t\t\t2.0*%s.x*dklmdx.x - %s.y*dklmdx.z - %s.z*dklmdx.y;\n",
+                                   fsName, fsName, fsName);
+            builder->fsCodeAppendf("\t\tfloat dfdy =\n"
+                                   "\t\t\t2.0*%s.x*dklmdy.x - %s.y*dklmdy.z - %s.z*dklmdy.y;\n",
+                                   fsName, fsName, fsName);
+            builder->fsCodeAppend("\t\tvec2 gF = vec2(dfdx, dfdy);\n");
+            builder->fsCodeAppend("\t\tfloat gFM = sqrt(dot(gF, gF));\n");
+            builder->fsCodeAppendf("\t\tfloat func = %s.x*%s.x - %s.y*%s.z;\n", fsName, fsName,
+                                   fsName, fsName);
+            builder->fsCodeAppend("\t\tfunc = abs(func);\n");
+            builder->fsCodeAppend("\t\tedgeAlpha = func / gFM;\n");
+            builder->fsCodeAppend("\t\tedgeAlpha = max(1.0 - edgeAlpha, 0.0);\n");
+            // Add line below for smooth cubic ramp
+            // builder->fsCodeAppend("\t\tedgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);\n");
+            break;
+        }
+        case kFillAA_GrBezierEdgeType: {
+            SkAssertResult(builder->enableFeature(
+                    GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
+            builder->fsCodeAppendf("\t\tvec3 dklmdx = dFdx(%s.xyz);\n", fsName);
+            builder->fsCodeAppendf("\t\tvec3 dklmdy = dFdy(%s.xyz);\n", fsName);
+            builder->fsCodeAppendf("\t\tfloat dfdx =\n"
+                                   "\t\t\t2.0*%s.x*dklmdx.x - %s.y*dklmdx.z - %s.z*dklmdx.y;\n",
+                                   fsName, fsName, fsName);
+            builder->fsCodeAppendf("\t\tfloat dfdy =\n"
+                                   "\t\t\t2.0*%s.x*dklmdy.x - %s.y*dklmdy.z - %s.z*dklmdy.y;\n",
+                                   fsName, fsName, fsName);
+            builder->fsCodeAppend("\t\tvec2 gF = vec2(dfdx, dfdy);\n");
+            builder->fsCodeAppend("\t\tfloat gFM = sqrt(dot(gF, gF));\n");
+            builder->fsCodeAppendf("\t\tfloat func = %s.x*%s.x - %s.y*%s.z;\n", fsName, fsName,
+                                   fsName, fsName);
+            builder->fsCodeAppend("\t\tedgeAlpha = func / gFM;\n");
+            builder->fsCodeAppend("\t\tedgeAlpha = clamp(1.0 - edgeAlpha, 0.0, 1.0);\n");
+            // Add line below for smooth cubic ramp
+            // builder->fsCodeAppend("\t\tedgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);\n");
+            break;
+        }
+        case kFillNoAA_GrBezierEdgeType: {
+            builder->fsCodeAppendf("\t\tedgeAlpha = %s.x*%s.x - %s.y*%s.z;\n", fsName, fsName,
+                                   fsName, fsName);
+            builder->fsCodeAppend("\t\tedgeAlpha = float(edgeAlpha < 0.0);\n");
+            break;
+        }
+    }
+
+    SkString modulate;
+    GrGLSLModulatef<4>(&modulate, inputColor, "edgeAlpha");
+    builder->fsCodeAppendf("\t%s = %s;\n", outputColor, modulate.c_str());
+}
+
+GrGLEffect::EffectKey GrGLConicEffect::GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
+    const GrConicEffect& ce = drawEffect.castEffect<GrConicEffect>();
+    return ce.isAntiAliased() ? (ce.isFilled() ? 0x0 : 0x1) : 0x2;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+GrConicEffect::~GrConicEffect() {}
+
+const GrBackendEffectFactory& GrConicEffect::getFactory() const {
+    return GrTBackendEffectFactory<GrConicEffect>::getInstance();
+}
+
+GrConicEffect::GrConicEffect(GrBezierEdgeType edgeType) : GrEffect() {
+    this->addVertexAttrib(kVec4f_GrSLType);
+    fEdgeType = edgeType;
+}
+
+bool GrConicEffect::onIsEqual(const GrEffect& other) const {
+    const GrConicEffect& ce = CastEffect<GrConicEffect>(other);
+    return (ce.fEdgeType == fEdgeType);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+GR_DEFINE_EFFECT_TEST(GrConicEffect);
+
+GrEffectRef* GrConicEffect::TestCreate(SkMWCRandom* random,
+                                             GrContext*,
+                                             const GrDrawTargetCaps& caps,
+                                             GrTexture*[]) {
+    const GrBezierEdgeType edgeType = static_cast<GrBezierEdgeType>(random->nextULessThan(3));
+    return GrConicEffect::Create(edgeType, caps);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// Quad
+//////////////////////////////////////////////////////////////////////////////
+
+class GrGLQuadEffect : public GrGLEffect {
+public:
+    GrGLQuadEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
+
+    virtual void emitCode(GrGLShaderBuilder* builder,
+                          const GrDrawEffect& drawEffect,
+                          EffectKey key,
+                          const char* outputColor,
+                          const char* inputColor,
+                          const TextureSamplerArray&) SK_OVERRIDE;
+
+    static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
+
+    virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {}
+
+private:
+    GrBezierEdgeType fEdgeType;
+
+    typedef GrGLEffect INHERITED;
+};
+    
+GrGLQuadEffect::GrGLQuadEffect(const GrBackendEffectFactory& factory,
+                                 const GrDrawEffect& drawEffect)
+    : INHERITED (factory) {
+    const GrQuadEffect& ce = drawEffect.castEffect<GrQuadEffect>();
+    fEdgeType = ce.getEdgeType();
+}
+
+void GrGLQuadEffect::emitCode(GrGLShaderBuilder* builder,
+                              const GrDrawEffect& drawEffect,
+                              EffectKey key,
+                              const char* outputColor,
+                              const char* inputColor,
+                              const TextureSamplerArray& samplers) {
+    const char *vsName, *fsName;
+
+    const SkString* attrName =
+        builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0]);
+    builder->fsCodeAppendf("\t\tfloat edgeAlpha;\n");
+
+    builder->addVarying(kVec4f_GrSLType, "HairQuadEdge", &vsName, &fsName);
+
+    switch (fEdgeType) {
+        case kHairAA_GrBezierEdgeType: {
+            SkAssertResult(builder->enableFeature(
+                    GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
+            builder->fsCodeAppendf("\t\tvec2 duvdx = dFdx(%s.xy);\n", fsName);
+            builder->fsCodeAppendf("\t\tvec2 duvdy = dFdy(%s.xy);\n", fsName);
+            builder->fsCodeAppendf("\t\tvec2 gF = vec2(2.0*%s.x*duvdx.x - duvdx.y,\n"
+                                   "\t\t               2.0*%s.x*duvdy.x - duvdy.y);\n",
+                                   fsName, fsName);
+            builder->fsCodeAppendf("\t\tedgeAlpha = (%s.x*%s.x - %s.y);\n", fsName, fsName,
+                                   fsName);
+            builder->fsCodeAppend("\t\tedgeAlpha = sqrt(edgeAlpha*edgeAlpha / dot(gF, gF));\n");
+            builder->fsCodeAppend("\t\tedgeAlpha = max(1.0 - edgeAlpha, 0.0);\n");
+            // Add line below for smooth cubic ramp
+            // builder->fsCodeAppend("\t\tedgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);\n");
+            break;
+        }
+        case kFillAA_GrBezierEdgeType: {
+            SkAssertResult(builder->enableFeature(
+                    GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
+            builder->fsCodeAppendf("\t\tvec2 duvdx = dFdx(%s.xy);\n", fsName);
+            builder->fsCodeAppendf("\t\tvec2 duvdy = dFdy(%s.xy);\n", fsName);
+            builder->fsCodeAppendf("\t\tvec2 gF = vec2(2.0*%s.x*duvdx.x - duvdx.y,\n"
+                                   "\t\t               2.0*%s.x*duvdy.x - duvdy.y);\n",
+                                   fsName, fsName);
+            builder->fsCodeAppendf("\t\tedgeAlpha = (%s.x*%s.x - %s.y);\n", fsName, fsName,
+                                   fsName);
+            builder->fsCodeAppend("\t\tedgeAlpha = edgeAlpha / sqrt(dot(gF, gF));\n");
+            builder->fsCodeAppend("\t\tedgeAlpha = clamp(1.0 - edgeAlpha, 0.0, 1.0);\n");
+            // Add line below for smooth cubic ramp
+            // builder->fsCodeAppend("\t\tedgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);\n");
+            break;
+        }
+        case kFillNoAA_GrBezierEdgeType: {
+            builder->fsCodeAppendf("\t\tedgeAlpha = (%s.x*%s.x - %s.y);\n", fsName, fsName,
+                                   fsName);
+            builder->fsCodeAppend("\t\tedgeAlpha = float(edgeAlpha < 0.0);\n");
+            break;
+        }
+    }
+
+    SkString modulate;
+    GrGLSLModulatef<4>(&modulate, inputColor, "edgeAlpha");
+    builder->fsCodeAppendf("\t%s = %s;\n", outputColor, modulate.c_str());
+
+    builder->vsCodeAppendf("\t%s = %s;\n", vsName, attrName->c_str());
+}
+
+GrGLEffect::EffectKey GrGLQuadEffect::GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
+    const GrQuadEffect& ce = drawEffect.castEffect<GrQuadEffect>();
+    return ce.isAntiAliased() ? (ce.isFilled() ? 0x0 : 0x1) : 0x2;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+GrQuadEffect::~GrQuadEffect() {}
+
+const GrBackendEffectFactory& GrQuadEffect::getFactory() const {
+    return GrTBackendEffectFactory<GrQuadEffect>::getInstance();
+}
+
+GrQuadEffect::GrQuadEffect(GrBezierEdgeType edgeType) : GrEffect() {
+    this->addVertexAttrib(kVec4f_GrSLType);
+    fEdgeType = edgeType;
+}
+
+bool GrQuadEffect::onIsEqual(const GrEffect& other) const {
+    const GrQuadEffect& ce = CastEffect<GrQuadEffect>(other);
+    return (ce.fEdgeType == fEdgeType);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+GR_DEFINE_EFFECT_TEST(GrQuadEffect);
+
+GrEffectRef* GrQuadEffect::TestCreate(SkMWCRandom* random,
+                                             GrContext*,
+                                             const GrDrawTargetCaps& caps,
+                                             GrTexture*[]) {
+    const GrBezierEdgeType edgeType = static_cast<GrBezierEdgeType>(random->nextULessThan(3));
+    return GrQuadEffect::Create(edgeType, caps);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// Cubic
+//////////////////////////////////////////////////////////////////////////////
+
+class GrGLCubicEffect : public GrGLEffect {
+public:
+    GrGLCubicEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
+
+    virtual void emitCode(GrGLShaderBuilder* builder,
+                          const GrDrawEffect& drawEffect,
+                          EffectKey key,
+                          const char* outputColor,
+                          const char* inputColor,
+                          const TextureSamplerArray&) SK_OVERRIDE;
+
+    static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
+
+    virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {}
+
+private:
+    GrBezierEdgeType fEdgeType;
+
+    typedef GrGLEffect INHERITED;
+};
+    
+GrGLCubicEffect::GrGLCubicEffect(const GrBackendEffectFactory& factory,
+                                 const GrDrawEffect& drawEffect)
+    : INHERITED (factory) {
+    const GrCubicEffect& ce = drawEffect.castEffect<GrCubicEffect>();
+    fEdgeType = ce.getEdgeType();
+}
+
+void GrGLCubicEffect::emitCode(GrGLShaderBuilder* builder,
+                               const GrDrawEffect& drawEffect,
+                               EffectKey key,
+                               const char* outputColor,
+                               const char* inputColor,
+                               const TextureSamplerArray& samplers) {
+    const char *vsName, *fsName;
+
+    builder->addVarying(kVec4f_GrSLType, "CubicCoeffs",
+                        &vsName, &fsName);
+    const SkString* attr0Name =
+        builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0]);
+    builder->vsCodeAppendf("\t%s = %s;\n", vsName, attr0Name->c_str());
+
+    builder->fsCodeAppend("\t\tfloat edgeAlpha;\n");
+
+    switch (fEdgeType) {
+        case kHairAA_GrBezierEdgeType: {
+            SkAssertResult(builder->enableFeature(
+                    GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
+            builder->fsCodeAppendf("\t\tvec3 dklmdx = dFdx(%s.xyz);\n", fsName);
+            builder->fsCodeAppendf("\t\tvec3 dklmdy = dFdy(%s.xyz);\n", fsName);
+            builder->fsCodeAppendf("\t\tfloat dfdx =\n"
+                                   "\t\t3.0*%s.x*%s.x*dklmdx.x - %s.y*dklmdx.z - %s.z*dklmdx.y;\n",
+                                   fsName, fsName, fsName, fsName);
+            builder->fsCodeAppendf("\t\tfloat dfdy =\n"
+                                   "\t\t3.0*%s.x*%s.x*dklmdy.x - %s.y*dklmdy.z - %s.z*dklmdy.y;\n",
+                                   fsName, fsName, fsName, fsName);
+            builder->fsCodeAppend("\t\tvec2 gF = vec2(dfdx, dfdy);\n");
+            builder->fsCodeAppend("\t\tfloat gFM = sqrt(dot(gF, gF));\n");
+            builder->fsCodeAppendf("\t\tfloat func = %s.x*%s.x*%s.x - %s.y*%s.z;\n",
+                                   fsName, fsName, fsName, fsName, fsName);
+            builder->fsCodeAppend("\t\tfunc = abs(func);\n");
+            builder->fsCodeAppend("\t\tedgeAlpha = func / gFM;\n");
+            builder->fsCodeAppend("\t\tedgeAlpha = max(1.0 - edgeAlpha, 0.0);\n");
+            // Add line below for smooth cubic ramp
+            // builder->fsCodeAppend("\t\tedgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);\n");
+            break;
+        }
+        case kFillAA_GrBezierEdgeType: {
+            SkAssertResult(builder->enableFeature(
+                    GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
+            builder->fsCodeAppendf("\t\tvec3 dklmdx = dFdx(%s.xyz);\n", fsName);
+            builder->fsCodeAppendf("\t\tvec3 dklmdy = dFdy(%s.xyz);\n", fsName);
+            builder->fsCodeAppendf("\t\tfloat dfdx =\n"
+                                   "\t\t3.0*%s.x*%s.x*dklmdx.x - %s.y*dklmdx.z - %s.z*dklmdx.y;\n",
+                                   fsName, fsName, fsName, fsName);
+            builder->fsCodeAppendf("\t\tfloat dfdy =\n"
+                                   "\t\t3.0*%s.x*%s.x*dklmdy.x - %s.y*dklmdy.z - %s.z*dklmdy.y;\n",
+                                   fsName, fsName, fsName, fsName);
+            builder->fsCodeAppend("\t\tvec2 gF = vec2(dfdx, dfdy);\n");
+            builder->fsCodeAppend("\t\tfloat gFM = sqrt(dot(gF, gF));\n");
+            builder->fsCodeAppendf("\t\tfloat func = %s.x*%s.x*%s.x - %s.y*%s.z;\n",
+                                   fsName, fsName, fsName, fsName, fsName);
+            builder->fsCodeAppend("\t\tedgeAlpha = func / gFM;\n");
+            builder->fsCodeAppend("\t\tedgeAlpha = clamp(1.0 - edgeAlpha, 0.0, 1.0);\n");
+            // Add line below for smooth cubic ramp
+            // builder->fsCodeAppend("\t\tedgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);\n");
+            break;
+        }
+        case kFillNoAA_GrBezierEdgeType: {
+            builder->fsCodeAppendf("\t\tedgeAlpha = %s.x*%s.x*%s.x - %s.y*%s.z;\n",
+                                   fsName, fsName, fsName, fsName, fsName);
+            builder->fsCodeAppend("\t\tedgeAlpha = float(edgeAlpha < 0.0);\n");
+            break;
+        }
+    }
+
+    SkString modulate;
+    GrGLSLModulatef<4>(&modulate, inputColor, "edgeAlpha");
+    builder->fsCodeAppendf("\t%s = %s;\n", outputColor, modulate.c_str());
+}
+
+GrGLEffect::EffectKey GrGLCubicEffect::GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
+    const GrCubicEffect& ce = drawEffect.castEffect<GrCubicEffect>();
+    return ce.isAntiAliased() ? (ce.isFilled() ? 0x0 : 0x1) : 0x2;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+GrCubicEffect::~GrCubicEffect() {}
+
+const GrBackendEffectFactory& GrCubicEffect::getFactory() const {
+    return GrTBackendEffectFactory<GrCubicEffect>::getInstance();
+}
+
+GrCubicEffect::GrCubicEffect(GrBezierEdgeType edgeType) : GrEffect() {
+    this->addVertexAttrib(kVec4f_GrSLType);
+    fEdgeType = edgeType;
+}
+
+bool GrCubicEffect::onIsEqual(const GrEffect& other) const {
+    const GrCubicEffect& ce = CastEffect<GrCubicEffect>(other);
+    return (ce.fEdgeType == fEdgeType);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+GR_DEFINE_EFFECT_TEST(GrCubicEffect);
+
+GrEffectRef* GrCubicEffect::TestCreate(SkMWCRandom* random,
+                                             GrContext*,
+                                             const GrDrawTargetCaps& caps,
+                                             GrTexture*[]) {
+    const GrBezierEdgeType edgeType = static_cast<GrBezierEdgeType>(random->nextULessThan(3));
+    return GrCubicEffect::Create(edgeType, caps);
+}