Pull out Effect Shaders in GPU Path Renderer

src/gpu/GrAAHairLinePathRenderer.cpp

Index: src/gpu/GrAAHairLinePathRenderer.cpp
diff --git a/src/gpu/GrAAHairLinePathRenderer.cpp b/src/gpu/GrAAHairLinePathRenderer.cpp
index f8c47d829ef5a4054657f54a7f21fd8284db0536..398e7b51cd044923eccde15da07897b3265ab1ab 100644
--- a/src/gpu/GrAAHairLinePathRenderer.cpp
+++ b/src/gpu/GrAAHairLinePathRenderer.cpp
@@ -19,8 +19,7 @@
 #include "SkStroke.h"
 #include "SkTemplates.h"
 
-#include "gl/GrGLEffect.h"
-#include "gl/GrGLSL.h"
+#include "effects/GrBezierEffect.h"
 
 namespace {
 // quadratics are rendered as 5-sided polys in order to bound the
@@ -694,346 +693,6 @@ void add_line(const SkPoint p[2],
 
 }
 
-/**
- * Shader is based off of "Resolution Independent Curve Rendering using
- * Programmable Graphics Hardware" by Loop and Blinn.
- * The output of this effect is a hairline edge for non rational cubics.
- * Cubics are specified by implicit equation K^3 - LM.
- * K, L, and M, are the first three values of the vertex attribute,
- * the fourth value is not used. Distance is calculated using a
- * first order approximation from the taylor series.
- * Coverage is max(0, 1-distance).
- */
-class HairCubicEdgeEffect : public GrEffect {
-public:
-    static GrEffectRef* Create() {
-        GR_CREATE_STATIC_EFFECT(gHairCubicEdgeEffect, HairCubicEdgeEffect, ());
-        gHairCubicEdgeEffect->ref();
-        return gHairCubicEdgeEffect;
-    }
-
-    virtual ~HairCubicEdgeEffect() {}
-
-    static const char* Name() { return "HairCubicEdge"; }
-
-    virtual void getConstantColorComponents(GrColor* color,
-                                            uint32_t* validFlags) const SK_OVERRIDE {
-        *validFlags = 0;
-    }
-
-    virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
-        return GrTBackendEffectFactory<HairCubicEdgeEffect>::getInstance();
-    }
-
-    class GLEffect : public GrGLEffect {
-    public:
-        GLEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&)
-            : INHERITED (factory) {}
-
-        virtual void emitCode(GrGLShaderBuilder* builder,
-                              const GrDrawEffect& drawEffect,
-                              EffectKey key,
-                              const char* outputColor,
-                              const char* inputColor,
-                              const TextureSamplerArray& samplers) SK_OVERRIDE {
-            const char *vsName, *fsName;
-
-            SkAssertResult(builder->enableFeature(
-                    GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
-            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");
-
-            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 = abs(%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 = 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");
-
-            SkString modulate;
-            GrGLSLModulatef<4>(&modulate, inputColor, "edgeAlpha");
-            builder->fsCodeAppendf("\t%s = %s;\n", outputColor, modulate.c_str());
-        }
-
-        static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
-            return 0x0;
-        }
-
-        virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {}
-
-    private:
-        typedef GrGLEffect INHERITED;
-    };
-private:
-    HairCubicEdgeEffect() {
-        this->addVertexAttrib(kVec4f_GrSLType);
-    }
-
-    virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE {
-        return true;
-    }
-
-    GR_DECLARE_EFFECT_TEST;
-
-    typedef GrEffect INHERITED;
-};
-
-/**
- * Shader is based off of Loop-Blinn Quadratic GPU Rendering
- * The output of this effect is a hairline edge for conics.
- * Conics specified by implicit equation K^2 - LM.
- * K, L, and M, are the first three values of the vertex attribute,
- * the fourth value is not used. Distance is calculated using a
- * first order approximation from the taylor series.
- * Coverage is max(0, 1-distance).
- */
-
-/**
- * Test were also run using a second order distance approximation.
- * There were two versions of the second order approx. The first version
- * is of roughly the form:
- * f(q) = |f(p)| - ||f'(p)||*||q-p|| - ||f''(p)||*||q-p||^2.
- * The second is similar:
- * f(q) = |f(p)| + ||f'(p)||*||q-p|| + ||f''(p)||*||q-p||^2.
- * The exact version of the equations can be found in the paper
- * "Distance Approximations for Rasterizing Implicit Curves" by Gabriel Taubin
- *
- * In both versions we solve the quadratic for ||q-p||.
- * Version 1:
- * gFM is magnitude of first partials and gFM2 is magnitude of 2nd partials (as derived from paper)
- * builder->fsCodeAppend("\t\tedgeAlpha = (sqrt(gFM*gFM+4.0*func*gF2M) - gFM)/(2.0*gF2M);\n");
- * Version 2:
- * builder->fsCodeAppend("\t\tedgeAlpha = (gFM - sqrt(gFM*gFM-4.0*func*gF2M))/(2.0*gF2M);\n");
- *
- * Also note that 2nd partials of k,l,m are zero
- *
- * When comparing the two second order approximations to the first order approximations,
- * the following results were found. Version 1 tends to underestimate the distances, thus it
- * basically increases all the error that we were already seeing in the first order
- * approx. So this version is not the one to use. Version 2 has the opposite effect
- * and tends to overestimate the distances. This is much closer to what we are
- * looking for. It is able to render ellipses (even thin ones) without the need to chop.
- * However, it can not handle thin hyperbolas well and thus would still rely on
- * chopping to tighten the clipping. Another side effect of the overestimating is
- * that the curves become much thinner and "ropey". If all that was ever rendered
- * were "not too thin" curves and ellipses then 2nd order may have an advantage since
- * only one geometry would need to be rendered. However no benches were run comparing
- * chopped first order and non chopped 2nd order.
- */
-class HairConicEdgeEffect : public GrEffect {
-public:
-    static GrEffectRef* Create() {
-        GR_CREATE_STATIC_EFFECT(gHairConicEdgeEffect, HairConicEdgeEffect, ());
-        gHairConicEdgeEffect->ref();
-        return gHairConicEdgeEffect;
-    }
-
-    virtual ~HairConicEdgeEffect() {}
-
-    static const char* Name() { return "HairConicEdge"; }
-
-    virtual void getConstantColorComponents(GrColor* color,
-                                            uint32_t* validFlags) const SK_OVERRIDE {
-        *validFlags = 0;
-    }
-
-    virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
-        return GrTBackendEffectFactory<HairConicEdgeEffect>::getInstance();
-    }
-
-    class GLEffect : public GrGLEffect {
-    public:
-        GLEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&)
-            : INHERITED (factory) {}
-
-        virtual void emitCode(GrGLShaderBuilder* builder,
-                              const GrDrawEffect& drawEffect,
-                              EffectKey key,
-                              const char* outputColor,
-                              const char* inputColor,
-                              const TextureSamplerArray& samplers) SK_OVERRIDE {
-            const char *vsName, *fsName;
-
-            SkAssertResult(builder->enableFeature(
-                    GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
-            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");
-
-            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 = abs(%s.x*%s.x - %s.y*%s.z);\n", fsName, fsName,
-                                   fsName, fsName);
-            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");
-
-            SkString modulate;
-            GrGLSLModulatef<4>(&modulate, inputColor, "edgeAlpha");
-            builder->fsCodeAppendf("\t%s = %s;\n", outputColor, modulate.c_str());
-        }
-
-        static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
-            return 0x0;
-        }
-
-        virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {}
-
-    private:
-        typedef GrGLEffect INHERITED;
-    };
-
-private:
-    HairConicEdgeEffect() {
-        this->addVertexAttrib(kVec4f_GrSLType);
-    }
-
-    virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE {
-        return true;
-    }
-
-    GR_DECLARE_EFFECT_TEST;
-
-    typedef GrEffect INHERITED;
-};
-
-GR_DEFINE_EFFECT_TEST(HairConicEdgeEffect);
-
-GrEffectRef* HairConicEdgeEffect::TestCreate(SkMWCRandom* random,
-                                             GrContext*,
-                                             const GrDrawTargetCaps& caps,
-                                             GrTexture*[]) {
-    return caps.shaderDerivativeSupport() ? HairConicEdgeEffect::Create() : NULL;
-}
-
-/**
- * The output of this effect is a hairline edge for quadratics.
- * Quadratic specified by 0=u^2-v canonical coords. u and v are the first
- * two components of the vertex attribute. Uses unsigned distance.
- * Coverage is min(0, 1-distance). 3rd & 4th component unused.
- * Requires shader derivative instruction support.
- */
-class HairQuadEdgeEffect : public GrEffect {
-public:
-
-    static GrEffectRef* Create() {
-        GR_CREATE_STATIC_EFFECT(gHairQuadEdgeEffect, HairQuadEdgeEffect, ());
-        gHairQuadEdgeEffect->ref();
-        return gHairQuadEdgeEffect;
-    }
-
-    virtual ~HairQuadEdgeEffect() {}
-
-    static const char* Name() { return "HairQuadEdge"; }
-
-    virtual void getConstantColorComponents(GrColor* color,
-                                            uint32_t* validFlags) const SK_OVERRIDE {
-        *validFlags = 0;
-    }
-
-    virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
-        return GrTBackendEffectFactory<HairQuadEdgeEffect>::getInstance();
-    }
-
-    class GLEffect : public GrGLEffect {
-    public:
-        GLEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&)
-            : INHERITED (factory) {}
-
-        virtual void emitCode(GrGLShaderBuilder* builder,
-                              const GrDrawEffect& drawEffect,
-                              EffectKey key,
-                              const char* outputColor,
-                              const char* inputColor,
-                              const TextureSamplerArray& samplers) SK_OVERRIDE {
-            const char *vsName, *fsName;
-            const SkString* attrName =
-                builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0]);
-            builder->fsCodeAppendf("\t\tfloat edgeAlpha;\n");
-
-            SkAssertResult(builder->enableFeature(
-                    GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
-            builder->addVarying(kVec4f_GrSLType, "HairQuadEdge", &vsName, &fsName);
-
-            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");
-
-            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());
-        }
-
-        static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
-            return 0x0;
-        }
-
-        virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {}
-
-    private:
-        typedef GrGLEffect INHERITED;
-    };
-
-private:
-    HairQuadEdgeEffect() {
-        this->addVertexAttrib(kVec4f_GrSLType);
-    }
-
-    virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE {
-        return true;
-    }
-
-    GR_DECLARE_EFFECT_TEST;
-
-    typedef GrEffect INHERITED;
-};
-
-GR_DEFINE_EFFECT_TEST(HairQuadEdgeEffect);
-
-GrEffectRef* HairQuadEdgeEffect::TestCreate(SkMWCRandom* random,
-                                            GrContext*,
-                                            const GrDrawTargetCaps& caps,
-                                            GrTexture*[]) {
-    // Doesn't work without derivative instructions.
-    return caps.shaderDerivativeSupport() ? HairQuadEdgeEffect::Create() : NULL;
-}
-
 ///////////////////////////////////////////////////////////////////////////////
 
 namespace {
@@ -1297,9 +956,12 @@ bool GrAAHairLinePathRenderer::onDrawPath(const SkPath& path,
 
         static const int kEdgeAttrIndex = 1;
 
-        GrEffectRef* hairQuadEffect = HairQuadEdgeEffect::Create();
-        GrEffectRef* hairConicEffect = HairConicEdgeEffect::Create();
-
+        GrEffectRef* hairQuadEffect = GrQuadEffect::Create(kHairAA_GrBezierEdgeType,
+                                                           *target->caps());
+        GrEffectRef* hairConicEffect = GrConicEffect::Create(kHairAA_GrBezierEdgeType,
+                                                             *target->caps());
+        SkASSERT(hairQuadEffect && hairConicEffect);
+        
         // Check devBounds
         SkASSERT(check_bounds<BezierVertex>(drawState, devBounds, arg.vertices(),
                                             kVertsPerQuad * quadCnt + kVertsPerQuad * conicCnt));