michael@0: /*
michael@0:  * Copyright 2013 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "GrOvalRenderer.h"
michael@0: 
michael@0: #include "GrEffect.h"
michael@0: #include "gl/GrGLEffect.h"
michael@0: #include "gl/GrGLSL.h"
michael@0: #include "gl/GrGLVertexEffect.h"
michael@0: #include "GrTBackendEffectFactory.h"
michael@0: 
michael@0: #include "GrDrawState.h"
michael@0: #include "GrDrawTarget.h"
michael@0: #include "GrGpu.h"
michael@0: 
michael@0: #include "SkRRect.h"
michael@0: #include "SkStrokeRec.h"
michael@0: 
michael@0: #include "effects/GrVertexEffect.h"
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: struct CircleVertex {
michael@0:     GrPoint  fPos;
michael@0:     GrPoint  fOffset;
michael@0:     SkScalar fOuterRadius;
michael@0:     SkScalar fInnerRadius;
michael@0: };
michael@0: 
michael@0: struct EllipseVertex {
michael@0:     GrPoint  fPos;
michael@0:     GrPoint  fOffset;
michael@0:     GrPoint  fOuterRadii;
michael@0:     GrPoint  fInnerRadii;
michael@0: };
michael@0: 
michael@0: struct DIEllipseVertex {
michael@0:     GrPoint  fPos;
michael@0:     GrPoint  fOuterOffset;
michael@0:     GrPoint  fInnerOffset;
michael@0: };
michael@0: 
michael@0: inline bool circle_stays_circle(const SkMatrix& m) {
michael@0:     return m.isSimilarity();
michael@0: }
michael@0: 
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: /**
michael@0:  * The output of this effect is a modulation of the input color and coverage for a circle,
michael@0:  * specified as offset_x, offset_y (both from center point), outer radius and inner radius.
michael@0:  */
michael@0: 
michael@0: class CircleEdgeEffect : public GrVertexEffect {
michael@0: public:
michael@0:     static GrEffectRef* Create(bool stroke) {
michael@0:         GR_CREATE_STATIC_EFFECT(gCircleStrokeEdge, CircleEdgeEffect, (true));
michael@0:         GR_CREATE_STATIC_EFFECT(gCircleFillEdge, CircleEdgeEffect, (false));
michael@0: 
michael@0:         if (stroke) {
michael@0:             gCircleStrokeEdge->ref();
michael@0:             return gCircleStrokeEdge;
michael@0:         } else {
michael@0:             gCircleFillEdge->ref();
michael@0:             return gCircleFillEdge;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     virtual void getConstantColorComponents(GrColor* color,
michael@0:                                             uint32_t* validFlags) const SK_OVERRIDE {
michael@0:         *validFlags = 0;
michael@0:     }
michael@0: 
michael@0:     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
michael@0:         return GrTBackendEffectFactory<CircleEdgeEffect>::getInstance();
michael@0:     }
michael@0: 
michael@0:     virtual ~CircleEdgeEffect() {}
michael@0: 
michael@0:     static const char* Name() { return "CircleEdge"; }
michael@0: 
michael@0:     inline bool isStroked() const { return fStroke; }
michael@0: 
michael@0:     class GLEffect : public GrGLVertexEffect {
michael@0:     public:
michael@0:         GLEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&)
michael@0:         : INHERITED (factory) {}
michael@0: 
michael@0:         virtual void emitCode(GrGLFullShaderBuilder* builder,
michael@0:                               const GrDrawEffect& drawEffect,
michael@0:                               EffectKey key,
michael@0:                               const char* outputColor,
michael@0:                               const char* inputColor,
michael@0:                               const TransformedCoordsArray&,
michael@0:                               const TextureSamplerArray& samplers) SK_OVERRIDE {
michael@0:             const CircleEdgeEffect& circleEffect = drawEffect.castEffect<CircleEdgeEffect>();
michael@0:             const char *vsName, *fsName;
michael@0:             builder->addVarying(kVec4f_GrSLType, "CircleEdge", &vsName, &fsName);
michael@0: 
michael@0:             const SkString* attrName =
michael@0:                 builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0]);
michael@0:             builder->vsCodeAppendf("\t%s = %s;\n", vsName, attrName->c_str());
michael@0: 
michael@0:             builder->fsCodeAppendf("\tfloat d = length(%s.xy);\n", fsName);
michael@0:             builder->fsCodeAppendf("\tfloat edgeAlpha = clamp(%s.z - d, 0.0, 1.0);\n", fsName);
michael@0:             if (circleEffect.isStroked()) {
michael@0:                 builder->fsCodeAppendf("\tfloat innerAlpha = clamp(d - %s.w, 0.0, 1.0);\n", fsName);
michael@0:                 builder->fsCodeAppend("\tedgeAlpha *= innerAlpha;\n");
michael@0:             }
michael@0: 
michael@0:             builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
michael@0:                                    (GrGLSLExpr4(inputColor) * GrGLSLExpr1("edgeAlpha")).c_str());
michael@0:         }
michael@0: 
michael@0:         static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
michael@0:             const CircleEdgeEffect& circleEffect = drawEffect.castEffect<CircleEdgeEffect>();
michael@0: 
michael@0:             return circleEffect.isStroked() ? 0x1 : 0x0;
michael@0:         }
michael@0: 
michael@0:         virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {}
michael@0: 
michael@0:     private:
michael@0:         typedef GrGLVertexEffect INHERITED;
michael@0:     };
michael@0: 
michael@0: 
michael@0: private:
michael@0:     CircleEdgeEffect(bool stroke) : GrVertexEffect() {
michael@0:         this->addVertexAttrib(kVec4f_GrSLType);
michael@0:         fStroke = stroke;
michael@0:     }
michael@0: 
michael@0:     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE {
michael@0:         const CircleEdgeEffect& cee = CastEffect<CircleEdgeEffect>(other);
michael@0:         return cee.fStroke == fStroke;
michael@0:     }
michael@0: 
michael@0:     bool fStroke;
michael@0: 
michael@0:     GR_DECLARE_EFFECT_TEST;
michael@0: 
michael@0:     typedef GrVertexEffect INHERITED;
michael@0: };
michael@0: 
michael@0: GR_DEFINE_EFFECT_TEST(CircleEdgeEffect);
michael@0: 
michael@0: GrEffectRef* CircleEdgeEffect::TestCreate(SkRandom* random,
michael@0:                                           GrContext* context,
michael@0:                                           const GrDrawTargetCaps&,
michael@0:                                           GrTexture* textures[]) {
michael@0:     return CircleEdgeEffect::Create(random->nextBool());
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: /**
michael@0:  * The output of this effect is a modulation of the input color and coverage for an axis-aligned
michael@0:  * ellipse, specified as a 2D offset from center, and the reciprocals of the outer and inner radii,
michael@0:  * in both x and y directions.
michael@0:  *
michael@0:  * We are using an implicit function of x^2/a^2 + y^2/b^2 - 1 = 0.
michael@0:  */
michael@0: 
michael@0: class EllipseEdgeEffect : public GrVertexEffect {
michael@0: public:
michael@0:     static GrEffectRef* Create(bool stroke) {
michael@0:         GR_CREATE_STATIC_EFFECT(gEllipseStrokeEdge, EllipseEdgeEffect, (true));
michael@0:         GR_CREATE_STATIC_EFFECT(gEllipseFillEdge, EllipseEdgeEffect, (false));
michael@0: 
michael@0:         if (stroke) {
michael@0:             gEllipseStrokeEdge->ref();
michael@0:             return gEllipseStrokeEdge;
michael@0:         } else {
michael@0:             gEllipseFillEdge->ref();
michael@0:             return gEllipseFillEdge;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     virtual void getConstantColorComponents(GrColor* color,
michael@0:                                             uint32_t* validFlags) const SK_OVERRIDE {
michael@0:         *validFlags = 0;
michael@0:     }
michael@0: 
michael@0:     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
michael@0:         return GrTBackendEffectFactory<EllipseEdgeEffect>::getInstance();
michael@0:     }
michael@0: 
michael@0:     virtual ~EllipseEdgeEffect() {}
michael@0: 
michael@0:     static const char* Name() { return "EllipseEdge"; }
michael@0: 
michael@0:     inline bool isStroked() const { return fStroke; }
michael@0: 
michael@0:     class GLEffect : public GrGLVertexEffect {
michael@0:     public:
michael@0:         GLEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&)
michael@0:         : INHERITED (factory) {}
michael@0: 
michael@0:         virtual void emitCode(GrGLFullShaderBuilder* builder,
michael@0:                               const GrDrawEffect& drawEffect,
michael@0:                               EffectKey key,
michael@0:                               const char* outputColor,
michael@0:                               const char* inputColor,
michael@0:                               const TransformedCoordsArray&,
michael@0:                               const TextureSamplerArray& samplers) SK_OVERRIDE {
michael@0:             const EllipseEdgeEffect& ellipseEffect = drawEffect.castEffect<EllipseEdgeEffect>();
michael@0: 
michael@0:             const char *vsOffsetName, *fsOffsetName;
michael@0:             const char *vsRadiiName, *fsRadiiName;
michael@0: 
michael@0:             builder->addVarying(kVec2f_GrSLType, "EllipseOffsets", &vsOffsetName, &fsOffsetName);
michael@0:             const SkString* attr0Name =
michael@0:                 builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0]);
michael@0:             builder->vsCodeAppendf("\t%s = %s;\n", vsOffsetName, attr0Name->c_str());
michael@0: 
michael@0:             builder->addVarying(kVec4f_GrSLType, "EllipseRadii", &vsRadiiName, &fsRadiiName);
michael@0:             const SkString* attr1Name =
michael@0:                 builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[1]);
michael@0:             builder->vsCodeAppendf("\t%s = %s;\n", vsRadiiName, attr1Name->c_str());
michael@0: 
michael@0:             // for outer curve
michael@0:             builder->fsCodeAppendf("\tvec2 scaledOffset = %s*%s.xy;\n", fsOffsetName, fsRadiiName);
michael@0:             builder->fsCodeAppend("\tfloat test = dot(scaledOffset, scaledOffset) - 1.0;\n");
michael@0:             builder->fsCodeAppendf("\tvec2 grad = 2.0*scaledOffset*%s.xy;\n", fsRadiiName);
michael@0:             builder->fsCodeAppend("\tfloat grad_dot = dot(grad, grad);\n");
michael@0:             // we need to clamp the length^2 of the gradiant vector to a non-zero value, because
michael@0:             // on the Nexus 4 the undefined result of inversesqrt(0) drops out an entire tile
michael@0:             // TODO: restrict this to Adreno-only
michael@0:             builder->fsCodeAppend("\tgrad_dot = max(grad_dot, 1.0e-4);\n");
michael@0:             builder->fsCodeAppend("\tfloat invlen = inversesqrt(grad_dot);\n");
michael@0:             builder->fsCodeAppend("\tfloat edgeAlpha = clamp(0.5-test*invlen, 0.0, 1.0);\n");
michael@0: 
michael@0:             // for inner curve
michael@0:             if (ellipseEffect.isStroked()) {
michael@0:                 builder->fsCodeAppendf("\tscaledOffset = %s*%s.zw;\n", fsOffsetName, fsRadiiName);
michael@0:                 builder->fsCodeAppend("\ttest = dot(scaledOffset, scaledOffset) - 1.0;\n");
michael@0:                 builder->fsCodeAppendf("\tgrad = 2.0*scaledOffset*%s.zw;\n", fsRadiiName);
michael@0:                 builder->fsCodeAppend("\tinvlen = inversesqrt(dot(grad, grad));\n");
michael@0:                 builder->fsCodeAppend("\tedgeAlpha *= clamp(0.5+test*invlen, 0.0, 1.0);\n");
michael@0:             }
michael@0: 
michael@0:             builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
michael@0:                                    (GrGLSLExpr4(inputColor) * GrGLSLExpr1("edgeAlpha")).c_str());
michael@0:         }
michael@0: 
michael@0:         static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
michael@0:             const EllipseEdgeEffect& ellipseEffect = drawEffect.castEffect<EllipseEdgeEffect>();
michael@0: 
michael@0:             return ellipseEffect.isStroked() ? 0x1 : 0x0;
michael@0:         }
michael@0: 
michael@0:         virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {
michael@0:         }
michael@0: 
michael@0:     private:
michael@0:         typedef GrGLVertexEffect INHERITED;
michael@0:     };
michael@0: 
michael@0: private:
michael@0:     EllipseEdgeEffect(bool stroke) : GrVertexEffect() {
michael@0:         this->addVertexAttrib(kVec2f_GrSLType);
michael@0:         this->addVertexAttrib(kVec4f_GrSLType);
michael@0:         fStroke = stroke;
michael@0:     }
michael@0: 
michael@0:     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE {
michael@0:         const EllipseEdgeEffect& eee = CastEffect<EllipseEdgeEffect>(other);
michael@0:         return eee.fStroke == fStroke;
michael@0:     }
michael@0: 
michael@0:     bool fStroke;
michael@0: 
michael@0:     GR_DECLARE_EFFECT_TEST;
michael@0: 
michael@0:     typedef GrVertexEffect INHERITED;
michael@0: };
michael@0: 
michael@0: GR_DEFINE_EFFECT_TEST(EllipseEdgeEffect);
michael@0: 
michael@0: GrEffectRef* EllipseEdgeEffect::TestCreate(SkRandom* random,
michael@0:                                            GrContext* context,
michael@0:                                            const GrDrawTargetCaps&,
michael@0:                                            GrTexture* textures[]) {
michael@0:     return EllipseEdgeEffect::Create(random->nextBool());
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: /**
michael@0:  * The output of this effect is a modulation of the input color and coverage for an ellipse,
michael@0:  * specified as a 2D offset from center for both the outer and inner paths (if stroked). The
michael@0:  * implict equation used is for a unit circle (x^2 + y^2 - 1 = 0) and the edge corrected by
michael@0:  * using differentials.
michael@0:  *
michael@0:  * The result is device-independent and can be used with any affine matrix.
michael@0:  */
michael@0: 
michael@0: class DIEllipseEdgeEffect : public GrVertexEffect {
michael@0: public:
michael@0:     enum Mode { kStroke = 0, kHairline, kFill };
michael@0: 
michael@0:     static GrEffectRef* Create(Mode mode) {
michael@0:         GR_CREATE_STATIC_EFFECT(gEllipseStrokeEdge, DIEllipseEdgeEffect, (kStroke));
michael@0:         GR_CREATE_STATIC_EFFECT(gEllipseHairlineEdge, DIEllipseEdgeEffect, (kHairline));
michael@0:         GR_CREATE_STATIC_EFFECT(gEllipseFillEdge, DIEllipseEdgeEffect, (kFill));
michael@0: 
michael@0:         if (kStroke == mode) {
michael@0:             gEllipseStrokeEdge->ref();
michael@0:             return gEllipseStrokeEdge;
michael@0:         } else if (kHairline == mode) {
michael@0:             gEllipseHairlineEdge->ref();
michael@0:             return gEllipseHairlineEdge;
michael@0:         } else {
michael@0:             gEllipseFillEdge->ref();
michael@0:             return gEllipseFillEdge;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     virtual void getConstantColorComponents(GrColor* color,
michael@0:                                             uint32_t* validFlags) const SK_OVERRIDE {
michael@0:         *validFlags = 0;
michael@0:     }
michael@0: 
michael@0:     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
michael@0:         return GrTBackendEffectFactory<DIEllipseEdgeEffect>::getInstance();
michael@0:     }
michael@0: 
michael@0:     virtual ~DIEllipseEdgeEffect() {}
michael@0: 
michael@0:     static const char* Name() { return "DIEllipseEdge"; }
michael@0: 
michael@0:     inline Mode getMode() const { return fMode; }
michael@0: 
michael@0:     class GLEffect : public GrGLVertexEffect {
michael@0:     public:
michael@0:         GLEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&)
michael@0:         : INHERITED (factory) {}
michael@0: 
michael@0:         virtual void emitCode(GrGLFullShaderBuilder* builder,
michael@0:                               const GrDrawEffect& drawEffect,
michael@0:                               EffectKey key,
michael@0:                               const char* outputColor,
michael@0:                               const char* inputColor,
michael@0:                               const TransformedCoordsArray&,
michael@0:                               const TextureSamplerArray& samplers) SK_OVERRIDE {
michael@0:             const DIEllipseEdgeEffect& ellipseEffect = drawEffect.castEffect<DIEllipseEdgeEffect>();
michael@0: 
michael@0:             SkAssertResult(builder->enableFeature(
michael@0:                                               GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
michael@0: 
michael@0:             const char *vsOffsetName0, *fsOffsetName0;
michael@0:             builder->addVarying(kVec2f_GrSLType, "EllipseOffsets0",
michael@0:                                       &vsOffsetName0, &fsOffsetName0);
michael@0:             const SkString* attr0Name =
michael@0:                 builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[0]);
michael@0:             builder->vsCodeAppendf("\t%s = %s;\n", vsOffsetName0, attr0Name->c_str());
michael@0:             const char *vsOffsetName1, *fsOffsetName1;
michael@0:             builder->addVarying(kVec2f_GrSLType, "EllipseOffsets1",
michael@0:                                       &vsOffsetName1, &fsOffsetName1);
michael@0:             const SkString* attr1Name =
michael@0:                 builder->getEffectAttributeName(drawEffect.getVertexAttribIndices()[1]);
michael@0:             builder->vsCodeAppendf("\t%s = %s;\n", vsOffsetName1, attr1Name->c_str());
michael@0: 
michael@0:             // for outer curve
michael@0:             builder->fsCodeAppendf("\tvec2 scaledOffset = %s.xy;\n", fsOffsetName0);
michael@0:             builder->fsCodeAppend("\tfloat test = dot(scaledOffset, scaledOffset) - 1.0;\n");
michael@0:             builder->fsCodeAppendf("\tvec2 duvdx = dFdx(%s);\n", fsOffsetName0);
michael@0:             builder->fsCodeAppendf("\tvec2 duvdy = dFdy(%s);\n", fsOffsetName0);
michael@0:             builder->fsCodeAppendf("\tvec2 grad = vec2(2.0*%s.x*duvdx.x + 2.0*%s.y*duvdx.y,\n"
michael@0:                                    "\t                 2.0*%s.x*duvdy.x + 2.0*%s.y*duvdy.y);\n",
michael@0:                                    fsOffsetName0, fsOffsetName0, fsOffsetName0, fsOffsetName0);
michael@0: 
michael@0:             builder->fsCodeAppend("\tfloat grad_dot = dot(grad, grad);\n");
michael@0:             // we need to clamp the length^2 of the gradiant vector to a non-zero value, because
michael@0:             // on the Nexus 4 the undefined result of inversesqrt(0) drops out an entire tile
michael@0:             // TODO: restrict this to Adreno-only
michael@0:             builder->fsCodeAppend("\tgrad_dot = max(grad_dot, 1.0e-4);\n");
michael@0:             builder->fsCodeAppend("\tfloat invlen = inversesqrt(grad_dot);\n");
michael@0:             if (kHairline == ellipseEffect.getMode()) {
michael@0:                 // can probably do this with one step
michael@0:                 builder->fsCodeAppend("\tfloat edgeAlpha = clamp(1.0-test*invlen, 0.0, 1.0);\n");
michael@0:                 builder->fsCodeAppend("\tedgeAlpha *= clamp(1.0+test*invlen, 0.0, 1.0);\n");
michael@0:             } else {
michael@0:                 builder->fsCodeAppend("\tfloat edgeAlpha = clamp(0.5-test*invlen, 0.0, 1.0);\n");
michael@0:             }
michael@0: 
michael@0:             // for inner curve
michael@0:             if (kStroke == ellipseEffect.getMode()) {
michael@0:                 builder->fsCodeAppendf("\tscaledOffset = %s.xy;\n", fsOffsetName1);
michael@0:                 builder->fsCodeAppend("\ttest = dot(scaledOffset, scaledOffset) - 1.0;\n");
michael@0:                 builder->fsCodeAppendf("\tduvdx = dFdx(%s);\n", fsOffsetName1);
michael@0:                 builder->fsCodeAppendf("\tduvdy = dFdy(%s);\n", fsOffsetName1);
michael@0:                 builder->fsCodeAppendf("\tgrad = vec2(2.0*%s.x*duvdx.x + 2.0*%s.y*duvdx.y,\n"
michael@0:                                        "\t            2.0*%s.x*duvdy.x + 2.0*%s.y*duvdy.y);\n",
michael@0:                                        fsOffsetName1, fsOffsetName1, fsOffsetName1, fsOffsetName1);
michael@0:                 builder->fsCodeAppend("\tinvlen = inversesqrt(dot(grad, grad));\n");
michael@0:                 builder->fsCodeAppend("\tedgeAlpha *= clamp(0.5+test*invlen, 0.0, 1.0);\n");
michael@0:             }
michael@0: 
michael@0:             builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
michael@0:                                    (GrGLSLExpr4(inputColor) * GrGLSLExpr1("edgeAlpha")).c_str());
michael@0:         }
michael@0: 
michael@0:         static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
michael@0:             const DIEllipseEdgeEffect& ellipseEffect = drawEffect.castEffect<DIEllipseEdgeEffect>();
michael@0: 
michael@0:             return ellipseEffect.getMode();
michael@0:         }
michael@0: 
michael@0:         virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE {
michael@0:         }
michael@0: 
michael@0:     private:
michael@0:         typedef GrGLVertexEffect INHERITED;
michael@0:     };
michael@0: 
michael@0: private:
michael@0:     DIEllipseEdgeEffect(Mode mode) : GrVertexEffect() {
michael@0:         this->addVertexAttrib(kVec2f_GrSLType);
michael@0:         this->addVertexAttrib(kVec2f_GrSLType);
michael@0:         fMode = mode;
michael@0:     }
michael@0: 
michael@0:     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE {
michael@0:         const DIEllipseEdgeEffect& eee = CastEffect<DIEllipseEdgeEffect>(other);
michael@0:         return eee.fMode == fMode;
michael@0:     }
michael@0: 
michael@0:     Mode fMode;
michael@0: 
michael@0:     GR_DECLARE_EFFECT_TEST;
michael@0: 
michael@0:     typedef GrVertexEffect INHERITED;
michael@0: };
michael@0: 
michael@0: GR_DEFINE_EFFECT_TEST(DIEllipseEdgeEffect);
michael@0: 
michael@0: GrEffectRef* DIEllipseEdgeEffect::TestCreate(SkRandom* random,
michael@0:                                              GrContext* context,
michael@0:                                              const GrDrawTargetCaps&,
michael@0:                                              GrTexture* textures[]) {
michael@0:     return DIEllipseEdgeEffect::Create((Mode)(random->nextRangeU(0,2)));
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: void GrOvalRenderer::reset() {
michael@0:     SkSafeSetNull(fRRectIndexBuffer);
michael@0: }
michael@0: 
michael@0: bool GrOvalRenderer::drawOval(GrDrawTarget* target, const GrContext* context, bool useAA,
michael@0:                               const SkRect& oval, const SkStrokeRec& stroke)
michael@0: {
michael@0:     bool useCoverageAA = useAA &&
michael@0:         !target->getDrawState().getRenderTarget()->isMultisampled() &&
michael@0:         !target->shouldDisableCoverageAAForBlend();
michael@0: 
michael@0:     if (!useCoverageAA) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     const SkMatrix& vm = context->getMatrix();
michael@0: 
michael@0:     // we can draw circles
michael@0:     if (SkScalarNearlyEqual(oval.width(), oval.height())
michael@0:         && circle_stays_circle(vm)) {
michael@0:         this->drawCircle(target, useCoverageAA, oval, stroke);
michael@0:     // if we have shader derivative support, render as device-independent
michael@0:     } else if (target->caps()->shaderDerivativeSupport()) {
michael@0:         return this->drawDIEllipse(target, useCoverageAA, oval, stroke);
michael@0:     // otherwise axis-aligned ellipses only
michael@0:     } else if (vm.rectStaysRect()) {
michael@0:         return this->drawEllipse(target, useCoverageAA, oval, stroke);
michael@0:     } else {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: // position + edge
michael@0: extern const GrVertexAttrib gCircleVertexAttribs[] = {
michael@0:     {kVec2f_GrVertexAttribType, 0,               kPosition_GrVertexAttribBinding},
michael@0:     {kVec4f_GrVertexAttribType, sizeof(GrPoint), kEffect_GrVertexAttribBinding}
michael@0: };
michael@0: 
michael@0: void GrOvalRenderer::drawCircle(GrDrawTarget* target,
michael@0:                                 bool useCoverageAA,
michael@0:                                 const SkRect& circle,
michael@0:                                 const SkStrokeRec& stroke)
michael@0: {
michael@0:     GrDrawState* drawState = target->drawState();
michael@0: 
michael@0:     const SkMatrix& vm = drawState->getViewMatrix();
michael@0:     GrPoint center = GrPoint::Make(circle.centerX(), circle.centerY());
michael@0:     vm.mapPoints(&center, 1);
michael@0:     SkScalar radius = vm.mapRadius(SkScalarHalf(circle.width()));
michael@0:     SkScalar strokeWidth = vm.mapRadius(stroke.getWidth());
michael@0: 
michael@0:     GrDrawState::AutoViewMatrixRestore avmr;
michael@0:     if (!avmr.setIdentity(drawState)) {
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     drawState->setVertexAttribs<gCircleVertexAttribs>(SK_ARRAY_COUNT(gCircleVertexAttribs));
michael@0:     SkASSERT(sizeof(CircleVertex) == drawState->getVertexSize());
michael@0: 
michael@0:     GrDrawTarget::AutoReleaseGeometry geo(target, 4, 0);
michael@0:     if (!geo.succeeded()) {
michael@0:         GrPrintf("Failed to get space for vertices!\n");
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     CircleVertex* verts = reinterpret_cast<CircleVertex*>(geo.vertices());
michael@0: 
michael@0:     SkStrokeRec::Style style = stroke.getStyle();
michael@0:     bool isStroked = (SkStrokeRec::kStroke_Style == style || SkStrokeRec::kHairline_Style == style);
michael@0: 
michael@0:     SkScalar innerRadius = 0.0f;
michael@0:     SkScalar outerRadius = radius;
michael@0:     SkScalar halfWidth = 0;
michael@0:     if (style != SkStrokeRec::kFill_Style) {
michael@0:         if (SkScalarNearlyZero(strokeWidth)) {
michael@0:             halfWidth = SK_ScalarHalf;
michael@0:         } else {
michael@0:             halfWidth = SkScalarHalf(strokeWidth);
michael@0:         }
michael@0: 
michael@0:         outerRadius += halfWidth;
michael@0:         if (isStroked) {
michael@0:             innerRadius = radius - halfWidth;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     GrEffectRef* effect = CircleEdgeEffect::Create(isStroked && innerRadius > 0);
michael@0:     static const int kCircleEdgeAttrIndex = 1;
michael@0:     drawState->addCoverageEffect(effect, kCircleEdgeAttrIndex)->unref();
michael@0: 
michael@0:     // The radii are outset for two reasons. First, it allows the shader to simply perform
michael@0:     // clamp(distance-to-center - radius, 0, 1). Second, the outer radius is used to compute the
michael@0:     // verts of the bounding box that is rendered and the outset ensures the box will cover all
michael@0:     // pixels partially covered by the circle.
michael@0:     outerRadius += SK_ScalarHalf;
michael@0:     innerRadius -= SK_ScalarHalf;
michael@0: 
michael@0:     SkRect bounds = SkRect::MakeLTRB(
michael@0:         center.fX - outerRadius,
michael@0:         center.fY - outerRadius,
michael@0:         center.fX + outerRadius,
michael@0:         center.fY + outerRadius
michael@0:     );
michael@0: 
michael@0:     verts[0].fPos = SkPoint::Make(bounds.fLeft,  bounds.fTop);
michael@0:     verts[0].fOffset = SkPoint::Make(-outerRadius, -outerRadius);
michael@0:     verts[0].fOuterRadius = outerRadius;
michael@0:     verts[0].fInnerRadius = innerRadius;
michael@0: 
michael@0:     verts[1].fPos = SkPoint::Make(bounds.fRight, bounds.fTop);
michael@0:     verts[1].fOffset = SkPoint::Make(outerRadius, -outerRadius);
michael@0:     verts[1].fOuterRadius = outerRadius;
michael@0:     verts[1].fInnerRadius = innerRadius;
michael@0: 
michael@0:     verts[2].fPos = SkPoint::Make(bounds.fLeft,  bounds.fBottom);
michael@0:     verts[2].fOffset = SkPoint::Make(-outerRadius, outerRadius);
michael@0:     verts[2].fOuterRadius = outerRadius;
michael@0:     verts[2].fInnerRadius = innerRadius;
michael@0: 
michael@0:     verts[3].fPos = SkPoint::Make(bounds.fRight, bounds.fBottom);
michael@0:     verts[3].fOffset = SkPoint::Make(outerRadius, outerRadius);
michael@0:     verts[3].fOuterRadius = outerRadius;
michael@0:     verts[3].fInnerRadius = innerRadius;
michael@0: 
michael@0:     target->drawNonIndexed(kTriangleStrip_GrPrimitiveType, 0, 4, &bounds);
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: // position + offset + 1/radii
michael@0: extern const GrVertexAttrib gEllipseVertexAttribs[] = {
michael@0:     {kVec2f_GrVertexAttribType, 0,                 kPosition_GrVertexAttribBinding},
michael@0:     {kVec2f_GrVertexAttribType, sizeof(GrPoint),   kEffect_GrVertexAttribBinding},
michael@0:     {kVec4f_GrVertexAttribType, 2*sizeof(GrPoint), kEffect_GrVertexAttribBinding}
michael@0: };
michael@0: 
michael@0: // position + offsets
michael@0: extern const GrVertexAttrib gDIEllipseVertexAttribs[] = {
michael@0:     {kVec2f_GrVertexAttribType, 0,                 kPosition_GrVertexAttribBinding},
michael@0:     {kVec2f_GrVertexAttribType, sizeof(GrPoint),   kEffect_GrVertexAttribBinding},
michael@0:     {kVec2f_GrVertexAttribType, 2*sizeof(GrPoint), kEffect_GrVertexAttribBinding},
michael@0: };
michael@0: 
michael@0: bool GrOvalRenderer::drawEllipse(GrDrawTarget* target,
michael@0:                                  bool useCoverageAA,
michael@0:                                  const SkRect& ellipse,
michael@0:                                  const SkStrokeRec& stroke)
michael@0: {
michael@0:     GrDrawState* drawState = target->drawState();
michael@0: #ifdef SK_DEBUG
michael@0:     {
michael@0:         // we should have checked for this previously
michael@0:         bool isAxisAlignedEllipse = drawState->getViewMatrix().rectStaysRect();
michael@0:         SkASSERT(useCoverageAA && isAxisAlignedEllipse);
michael@0:     }
michael@0: #endif
michael@0: 
michael@0:     // do any matrix crunching before we reset the draw state for device coords
michael@0:     const SkMatrix& vm = drawState->getViewMatrix();
michael@0:     GrPoint center = GrPoint::Make(ellipse.centerX(), ellipse.centerY());
michael@0:     vm.mapPoints(&center, 1);
michael@0:     SkScalar ellipseXRadius = SkScalarHalf(ellipse.width());
michael@0:     SkScalar ellipseYRadius = SkScalarHalf(ellipse.height());
michael@0:     SkScalar xRadius = SkScalarAbs(vm[SkMatrix::kMScaleX]*ellipseXRadius +
michael@0:                                    vm[SkMatrix::kMSkewY]*ellipseYRadius);
michael@0:     SkScalar yRadius = SkScalarAbs(vm[SkMatrix::kMSkewX]*ellipseXRadius +
michael@0:                                    vm[SkMatrix::kMScaleY]*ellipseYRadius);
michael@0: 
michael@0:     // do (potentially) anisotropic mapping of stroke
michael@0:     SkVector scaledStroke;
michael@0:     SkScalar strokeWidth = stroke.getWidth();
michael@0:     scaledStroke.fX = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMScaleX] + vm[SkMatrix::kMSkewY]));
michael@0:     scaledStroke.fY = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMSkewX] + vm[SkMatrix::kMScaleY]));
michael@0: 
michael@0:     SkStrokeRec::Style style = stroke.getStyle();
michael@0:     bool isStroked = (SkStrokeRec::kStroke_Style == style || SkStrokeRec::kHairline_Style == style);
michael@0: 
michael@0:     SkScalar innerXRadius = 0;
michael@0:     SkScalar innerYRadius = 0;
michael@0:     if (SkStrokeRec::kFill_Style != style) {
michael@0:         if (SkScalarNearlyZero(scaledStroke.length())) {
michael@0:             scaledStroke.set(SK_ScalarHalf, SK_ScalarHalf);
michael@0:         } else {
michael@0:             scaledStroke.scale(SK_ScalarHalf);
michael@0:         }
michael@0: 
michael@0:         // we only handle thick strokes for near-circular ellipses
michael@0:         if (scaledStroke.length() > SK_ScalarHalf &&
michael@0:             (SK_ScalarHalf*xRadius > yRadius || SK_ScalarHalf*yRadius > xRadius)) {
michael@0:             return false;
michael@0:         }
michael@0: 
michael@0:         // we don't handle it if curvature of the stroke is less than curvature of the ellipse
michael@0:         if (scaledStroke.fX*(yRadius*yRadius) < (scaledStroke.fY*scaledStroke.fY)*xRadius ||
michael@0:             scaledStroke.fY*(xRadius*xRadius) < (scaledStroke.fX*scaledStroke.fX)*yRadius) {
michael@0:             return false;
michael@0:         }
michael@0: 
michael@0:         // this is legit only if scale & translation (which should be the case at the moment)
michael@0:         if (isStroked) {
michael@0:             innerXRadius = xRadius - scaledStroke.fX;
michael@0:             innerYRadius = yRadius - scaledStroke.fY;
michael@0:         }
michael@0: 
michael@0:         xRadius += scaledStroke.fX;
michael@0:         yRadius += scaledStroke.fY;
michael@0:     }
michael@0: 
michael@0:     GrDrawState::AutoViewMatrixRestore avmr;
michael@0:     if (!avmr.setIdentity(drawState)) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     drawState->setVertexAttribs<gEllipseVertexAttribs>(SK_ARRAY_COUNT(gEllipseVertexAttribs));
michael@0:     SkASSERT(sizeof(EllipseVertex) == drawState->getVertexSize());
michael@0: 
michael@0:     GrDrawTarget::AutoReleaseGeometry geo(target, 4, 0);
michael@0:     if (!geo.succeeded()) {
michael@0:         GrPrintf("Failed to get space for vertices!\n");
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(geo.vertices());
michael@0: 
michael@0:     GrEffectRef* effect = EllipseEdgeEffect::Create(isStroked &&
michael@0:                                                     innerXRadius > 0 && innerYRadius > 0);
michael@0: 
michael@0:     static const int kEllipseCenterAttrIndex = 1;
michael@0:     static const int kEllipseEdgeAttrIndex = 2;
michael@0:     drawState->addCoverageEffect(effect, kEllipseCenterAttrIndex, kEllipseEdgeAttrIndex)->unref();
michael@0: 
michael@0:     // Compute the reciprocals of the radii here to save time in the shader
michael@0:     SkScalar xRadRecip = SkScalarInvert(xRadius);
michael@0:     SkScalar yRadRecip = SkScalarInvert(yRadius);
michael@0:     SkScalar xInnerRadRecip = SkScalarInvert(innerXRadius);
michael@0:     SkScalar yInnerRadRecip = SkScalarInvert(innerYRadius);
michael@0: 
michael@0:     // We've extended the outer x radius out half a pixel to antialias.
michael@0:     // This will also expand the rect so all the pixels will be captured.
michael@0:     // TODO: Consider if we should use sqrt(2)/2 instead
michael@0:     xRadius += SK_ScalarHalf;
michael@0:     yRadius += SK_ScalarHalf;
michael@0: 
michael@0:     SkRect bounds = SkRect::MakeLTRB(
michael@0:         center.fX - xRadius,
michael@0:         center.fY - yRadius,
michael@0:         center.fX + xRadius,
michael@0:         center.fY + yRadius
michael@0:     );
michael@0: 
michael@0:     verts[0].fPos = SkPoint::Make(bounds.fLeft,  bounds.fTop);
michael@0:     verts[0].fOffset = SkPoint::Make(-xRadius, -yRadius);
michael@0:     verts[0].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
michael@0:     verts[0].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
michael@0: 
michael@0:     verts[1].fPos = SkPoint::Make(bounds.fRight, bounds.fTop);
michael@0:     verts[1].fOffset = SkPoint::Make(xRadius, -yRadius);
michael@0:     verts[1].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
michael@0:     verts[1].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
michael@0: 
michael@0:     verts[2].fPos = SkPoint::Make(bounds.fLeft,  bounds.fBottom);
michael@0:     verts[2].fOffset = SkPoint::Make(-xRadius, yRadius);
michael@0:     verts[2].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
michael@0:     verts[2].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
michael@0: 
michael@0:     verts[3].fPos = SkPoint::Make(bounds.fRight, bounds.fBottom);
michael@0:     verts[3].fOffset = SkPoint::Make(xRadius, yRadius);
michael@0:     verts[3].fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
michael@0:     verts[3].fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
michael@0: 
michael@0:     target->drawNonIndexed(kTriangleStrip_GrPrimitiveType, 0, 4, &bounds);
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool GrOvalRenderer::drawDIEllipse(GrDrawTarget* target,
michael@0:                                    bool useCoverageAA,
michael@0:                                    const SkRect& ellipse,
michael@0:                                    const SkStrokeRec& stroke)
michael@0: {
michael@0:     GrDrawState* drawState = target->drawState();
michael@0:     const SkMatrix& vm = drawState->getViewMatrix();
michael@0: 
michael@0:     GrPoint center = GrPoint::Make(ellipse.centerX(), ellipse.centerY());
michael@0:     SkScalar xRadius = SkScalarHalf(ellipse.width());
michael@0:     SkScalar yRadius = SkScalarHalf(ellipse.height());
michael@0: 
michael@0:     SkStrokeRec::Style style = stroke.getStyle();
michael@0:     DIEllipseEdgeEffect::Mode mode = (SkStrokeRec::kStroke_Style == style) ?
michael@0:                                     DIEllipseEdgeEffect::kStroke :
michael@0:                                     (SkStrokeRec::kHairline_Style == style) ?
michael@0:                                     DIEllipseEdgeEffect::kHairline : DIEllipseEdgeEffect::kFill;
michael@0: 
michael@0:     SkScalar innerXRadius = 0;
michael@0:     SkScalar innerYRadius = 0;
michael@0:     if (SkStrokeRec::kFill_Style != style && SkStrokeRec::kHairline_Style != style) {
michael@0:         SkScalar strokeWidth = stroke.getWidth();
michael@0: 
michael@0:         if (SkScalarNearlyZero(strokeWidth)) {
michael@0:             strokeWidth = SK_ScalarHalf;
michael@0:         } else {
michael@0:             strokeWidth *= SK_ScalarHalf;
michael@0:         }
michael@0: 
michael@0:         // we only handle thick strokes for near-circular ellipses
michael@0:         if (strokeWidth > SK_ScalarHalf &&
michael@0:             (SK_ScalarHalf*xRadius > yRadius || SK_ScalarHalf*yRadius > xRadius)) {
michael@0:             return false;
michael@0:         }
michael@0: 
michael@0:         // we don't handle it if curvature of the stroke is less than curvature of the ellipse
michael@0:         if (strokeWidth*(yRadius*yRadius) < (strokeWidth*strokeWidth)*xRadius ||
michael@0:             strokeWidth*(xRadius*xRadius) < (strokeWidth*strokeWidth)*yRadius) {
michael@0:             return false;
michael@0:         }
michael@0: 
michael@0:         // set inner radius (if needed)
michael@0:         if (SkStrokeRec::kStroke_Style == style) {
michael@0:             innerXRadius = xRadius - strokeWidth;
michael@0:             innerYRadius = yRadius - strokeWidth;
michael@0:         }
michael@0: 
michael@0:         xRadius += strokeWidth;
michael@0:         yRadius += strokeWidth;
michael@0:     }
michael@0:     if (DIEllipseEdgeEffect::kStroke == mode) {
michael@0:         mode = (innerXRadius > 0 && innerYRadius > 0) ? DIEllipseEdgeEffect::kStroke :
michael@0:                                                         DIEllipseEdgeEffect::kFill;
michael@0:     }
michael@0:     SkScalar innerRatioX = SkScalarDiv(xRadius, innerXRadius);
michael@0:     SkScalar innerRatioY = SkScalarDiv(yRadius, innerYRadius);
michael@0: 
michael@0:     drawState->setVertexAttribs<gDIEllipseVertexAttribs>(SK_ARRAY_COUNT(gDIEllipseVertexAttribs));
michael@0:     SkASSERT(sizeof(DIEllipseVertex) == drawState->getVertexSize());
michael@0: 
michael@0:     GrDrawTarget::AutoReleaseGeometry geo(target, 4, 0);
michael@0:     if (!geo.succeeded()) {
michael@0:         GrPrintf("Failed to get space for vertices!\n");
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     DIEllipseVertex* verts = reinterpret_cast<DIEllipseVertex*>(geo.vertices());
michael@0: 
michael@0:     GrEffectRef* effect = DIEllipseEdgeEffect::Create(mode);
michael@0: 
michael@0:     static const int kEllipseOuterOffsetAttrIndex = 1;
michael@0:     static const int kEllipseInnerOffsetAttrIndex = 2;
michael@0:     drawState->addCoverageEffect(effect, kEllipseOuterOffsetAttrIndex,
michael@0:                                          kEllipseInnerOffsetAttrIndex)->unref();
michael@0: 
michael@0:     // This expands the outer rect so that after CTM we end up with a half-pixel border
michael@0:     SkScalar a = vm[SkMatrix::kMScaleX];
michael@0:     SkScalar b = vm[SkMatrix::kMSkewX];
michael@0:     SkScalar c = vm[SkMatrix::kMSkewY];
michael@0:     SkScalar d = vm[SkMatrix::kMScaleY];
michael@0:     SkScalar geoDx = SkScalarDiv(SK_ScalarHalf, SkScalarSqrt(a*a + c*c));
michael@0:     SkScalar geoDy = SkScalarDiv(SK_ScalarHalf, SkScalarSqrt(b*b + d*d));
michael@0:     // This adjusts the "radius" to include the half-pixel border
michael@0:     SkScalar offsetDx = SkScalarDiv(geoDx, xRadius);
michael@0:     SkScalar offsetDy = SkScalarDiv(geoDy, yRadius);
michael@0: 
michael@0:     SkRect bounds = SkRect::MakeLTRB(
michael@0:         center.fX - xRadius - geoDx,
michael@0:         center.fY - yRadius - geoDy,
michael@0:         center.fX + xRadius + geoDx,
michael@0:         center.fY + yRadius + geoDy
michael@0:     );
michael@0: 
michael@0:     verts[0].fPos = SkPoint::Make(bounds.fLeft, bounds.fTop);
michael@0:     verts[0].fOuterOffset = SkPoint::Make(-1.0f - offsetDx, -1.0f - offsetDy);
michael@0:     verts[0].fInnerOffset = SkPoint::Make(-innerRatioX - offsetDx, -innerRatioY - offsetDy);
michael@0: 
michael@0:     verts[1].fPos = SkPoint::Make(bounds.fRight, bounds.fTop);
michael@0:     verts[1].fOuterOffset = SkPoint::Make(1.0f + offsetDx, -1.0f - offsetDy);
michael@0:     verts[1].fInnerOffset = SkPoint::Make(innerRatioX + offsetDx, -innerRatioY - offsetDy);
michael@0: 
michael@0:     verts[2].fPos = SkPoint::Make(bounds.fLeft,  bounds.fBottom);
michael@0:     verts[2].fOuterOffset = SkPoint::Make(-1.0f - offsetDx, 1.0f + offsetDy);
michael@0:     verts[2].fInnerOffset = SkPoint::Make(-innerRatioX - offsetDx, innerRatioY + offsetDy);
michael@0: 
michael@0:     verts[3].fPos = SkPoint::Make(bounds.fRight, bounds.fBottom);
michael@0:     verts[3].fOuterOffset = SkPoint::Make(1.0f + offsetDx, 1.0f + offsetDy);
michael@0:     verts[3].fInnerOffset = SkPoint::Make(innerRatioX + offsetDx, innerRatioY + offsetDy);
michael@0: 
michael@0:     target->drawNonIndexed(kTriangleStrip_GrPrimitiveType, 0, 4, &bounds);
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: static const uint16_t gRRectIndices[] = {
michael@0:     // corners
michael@0:     0, 1, 5, 0, 5, 4,
michael@0:     2, 3, 7, 2, 7, 6,
michael@0:     8, 9, 13, 8, 13, 12,
michael@0:     10, 11, 15, 10, 15, 14,
michael@0: 
michael@0:     // edges
michael@0:     1, 2, 6, 1, 6, 5,
michael@0:     4, 5, 9, 4, 9, 8,
michael@0:     6, 7, 11, 6, 11, 10,
michael@0:     9, 10, 14, 9, 14, 13,
michael@0: 
michael@0:     // center
michael@0:     // we place this at the end so that we can ignore these indices when rendering stroke-only
michael@0:     5, 6, 10, 5, 10, 9
michael@0: };
michael@0: 
michael@0: 
michael@0: GrIndexBuffer* GrOvalRenderer::rRectIndexBuffer(GrGpu* gpu) {
michael@0:     if (NULL == fRRectIndexBuffer) {
michael@0:         fRRectIndexBuffer =
michael@0:         gpu->createIndexBuffer(sizeof(gRRectIndices), false);
michael@0:         if (NULL != fRRectIndexBuffer) {
michael@0: #ifdef SK_DEBUG
michael@0:             bool updated =
michael@0: #endif
michael@0:             fRRectIndexBuffer->updateData(gRRectIndices,
michael@0:                                           sizeof(gRRectIndices));
michael@0:             GR_DEBUGASSERT(updated);
michael@0:         }
michael@0:     }
michael@0:     return fRRectIndexBuffer;
michael@0: }
michael@0: 
michael@0: bool GrOvalRenderer::drawSimpleRRect(GrDrawTarget* target, GrContext* context, bool useAA,
michael@0:                                      const SkRRect& rrect, const SkStrokeRec& stroke)
michael@0: {
michael@0:     bool useCoverageAA = useAA &&
michael@0:         !target->getDrawState().getRenderTarget()->isMultisampled() &&
michael@0:         !target->shouldDisableCoverageAAForBlend();
michael@0: 
michael@0:     // only anti-aliased rrects for now
michael@0:     if (!useCoverageAA) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     const SkMatrix& vm = context->getMatrix();
michael@0: #ifdef SK_DEBUG
michael@0:     {
michael@0:         // we should have checked for this previously
michael@0:         SkASSERT(useCoverageAA && vm.rectStaysRect() && rrect.isSimple());
michael@0:     }
michael@0: #endif
michael@0: 
michael@0:     // do any matrix crunching before we reset the draw state for device coords
michael@0:     const SkRect& rrectBounds = rrect.getBounds();
michael@0:     SkRect bounds;
michael@0:     vm.mapRect(&bounds, rrectBounds);
michael@0: 
michael@0:     SkVector radii = rrect.getSimpleRadii();
michael@0:     SkScalar xRadius = SkScalarAbs(vm[SkMatrix::kMScaleX]*radii.fX +
michael@0:                                    vm[SkMatrix::kMSkewY]*radii.fY);
michael@0:     SkScalar yRadius = SkScalarAbs(vm[SkMatrix::kMSkewX]*radii.fX +
michael@0:                                    vm[SkMatrix::kMScaleY]*radii.fY);
michael@0: 
michael@0:     // if hairline stroke is greater than radius, we don't handle that right now
michael@0:     SkStrokeRec::Style style = stroke.getStyle();
michael@0:     if (SkStrokeRec::kHairline_Style == style &&
michael@0:         (SK_ScalarHalf > xRadius || SK_ScalarHalf > yRadius)) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     // do (potentially) anisotropic mapping of stroke
michael@0:     SkVector scaledStroke;
michael@0:     SkScalar strokeWidth = stroke.getWidth();
michael@0:     scaledStroke.fX = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMScaleX] + vm[SkMatrix::kMSkewY]));
michael@0:     scaledStroke.fY = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMSkewX] + vm[SkMatrix::kMScaleY]));
michael@0: 
michael@0:     // if half of strokewidth is greater than radius, we don't handle that right now
michael@0:     if (SK_ScalarHalf*scaledStroke.fX > xRadius || SK_ScalarHalf*scaledStroke.fY > yRadius) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     // reset to device coordinates
michael@0:     GrDrawState* drawState = target->drawState();
michael@0:     GrDrawState::AutoViewMatrixRestore avmr;
michael@0:     if (!avmr.setIdentity(drawState)) {
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     bool isStroked = (SkStrokeRec::kStroke_Style == style || SkStrokeRec::kHairline_Style == style);
michael@0: 
michael@0:     GrIndexBuffer* indexBuffer = this->rRectIndexBuffer(context->getGpu());
michael@0:     if (NULL == indexBuffer) {
michael@0:         GrPrintf("Failed to create index buffer!\n");
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     // if the corners are circles, use the circle renderer
michael@0:     if ((!isStroked || scaledStroke.fX == scaledStroke.fY) && xRadius == yRadius) {
michael@0:         drawState->setVertexAttribs<gCircleVertexAttribs>(SK_ARRAY_COUNT(gCircleVertexAttribs));
michael@0:         SkASSERT(sizeof(CircleVertex) == drawState->getVertexSize());
michael@0: 
michael@0:         GrDrawTarget::AutoReleaseGeometry geo(target, 16, 0);
michael@0:         if (!geo.succeeded()) {
michael@0:             GrPrintf("Failed to get space for vertices!\n");
michael@0:             return false;
michael@0:         }
michael@0:         CircleVertex* verts = reinterpret_cast<CircleVertex*>(geo.vertices());
michael@0: 
michael@0:         SkScalar innerRadius = 0.0f;
michael@0:         SkScalar outerRadius = xRadius;
michael@0:         SkScalar halfWidth = 0;
michael@0:         if (style != SkStrokeRec::kFill_Style) {
michael@0:             if (SkScalarNearlyZero(scaledStroke.fX)) {
michael@0:                 halfWidth = SK_ScalarHalf;
michael@0:             } else {
michael@0:                 halfWidth = SkScalarHalf(scaledStroke.fX);
michael@0:             }
michael@0: 
michael@0:             if (isStroked) {
michael@0:                 innerRadius = xRadius - halfWidth;
michael@0:             }
michael@0:             outerRadius += halfWidth;
michael@0:             bounds.outset(halfWidth, halfWidth);
michael@0:         }
michael@0: 
michael@0:         isStroked = (isStroked && innerRadius >= 0);
michael@0: 
michael@0:         GrEffectRef* effect = CircleEdgeEffect::Create(isStroked);
michael@0:         static const int kCircleEdgeAttrIndex = 1;
michael@0:         drawState->addCoverageEffect(effect, kCircleEdgeAttrIndex)->unref();
michael@0: 
michael@0:         // The radii are outset for two reasons. First, it allows the shader to simply perform
michael@0:         // clamp(distance-to-center - radius, 0, 1). Second, the outer radius is used to compute the
michael@0:         // verts of the bounding box that is rendered and the outset ensures the box will cover all
michael@0:         // pixels partially covered by the circle.
michael@0:         outerRadius += SK_ScalarHalf;
michael@0:         innerRadius -= SK_ScalarHalf;
michael@0: 
michael@0:         // Expand the rect so all the pixels will be captured.
michael@0:         bounds.outset(SK_ScalarHalf, SK_ScalarHalf);
michael@0: 
michael@0:         SkScalar yCoords[4] = {
michael@0:             bounds.fTop,
michael@0:             bounds.fTop + outerRadius,
michael@0:             bounds.fBottom - outerRadius,
michael@0:             bounds.fBottom
michael@0:         };
michael@0:         SkScalar yOuterRadii[4] = {
michael@0:             -outerRadius,
michael@0:             0,
michael@0:             0,
michael@0:             outerRadius
michael@0:         };
michael@0:         for (int i = 0; i < 4; ++i) {
michael@0:             verts->fPos = SkPoint::Make(bounds.fLeft, yCoords[i]);
michael@0:             verts->fOffset = SkPoint::Make(-outerRadius, yOuterRadii[i]);
michael@0:             verts->fOuterRadius = outerRadius;
michael@0:             verts->fInnerRadius = innerRadius;
michael@0:             verts++;
michael@0: 
michael@0:             verts->fPos = SkPoint::Make(bounds.fLeft + outerRadius, yCoords[i]);
michael@0:             verts->fOffset = SkPoint::Make(0, yOuterRadii[i]);
michael@0:             verts->fOuterRadius = outerRadius;
michael@0:             verts->fInnerRadius = innerRadius;
michael@0:             verts++;
michael@0: 
michael@0:             verts->fPos = SkPoint::Make(bounds.fRight - outerRadius, yCoords[i]);
michael@0:             verts->fOffset = SkPoint::Make(0, yOuterRadii[i]);
michael@0:             verts->fOuterRadius = outerRadius;
michael@0:             verts->fInnerRadius = innerRadius;
michael@0:             verts++;
michael@0: 
michael@0:             verts->fPos = SkPoint::Make(bounds.fRight, yCoords[i]);
michael@0:             verts->fOffset = SkPoint::Make(outerRadius, yOuterRadii[i]);
michael@0:             verts->fOuterRadius = outerRadius;
michael@0:             verts->fInnerRadius = innerRadius;
michael@0:             verts++;
michael@0:         }
michael@0: 
michael@0:         // drop out the middle quad if we're stroked
michael@0:         int indexCnt = isStroked ? GR_ARRAY_COUNT(gRRectIndices)-6 : GR_ARRAY_COUNT(gRRectIndices);
michael@0:         target->setIndexSourceToBuffer(indexBuffer);
michael@0:         target->drawIndexed(kTriangles_GrPrimitiveType, 0, 0, 16, indexCnt, &bounds);
michael@0: 
michael@0:     // otherwise we use the ellipse renderer
michael@0:     } else {
michael@0:         drawState->setVertexAttribs<gEllipseVertexAttribs>(SK_ARRAY_COUNT(gEllipseVertexAttribs));
michael@0:         SkASSERT(sizeof(EllipseVertex) == drawState->getVertexSize());
michael@0: 
michael@0:         SkScalar innerXRadius = 0.0f;
michael@0:         SkScalar innerYRadius = 0.0f;
michael@0:         if (SkStrokeRec::kFill_Style != style) {
michael@0:             if (SkScalarNearlyZero(scaledStroke.length())) {
michael@0:                 scaledStroke.set(SK_ScalarHalf, SK_ScalarHalf);
michael@0:             } else {
michael@0:                 scaledStroke.scale(SK_ScalarHalf);
michael@0:             }
michael@0: 
michael@0:             // we only handle thick strokes for near-circular ellipses
michael@0:             if (scaledStroke.length() > SK_ScalarHalf &&
michael@0:                 (SK_ScalarHalf*xRadius > yRadius || SK_ScalarHalf*yRadius > xRadius)) {
michael@0:                 return false;
michael@0:             }
michael@0: 
michael@0:             // we don't handle it if curvature of the stroke is less than curvature of the ellipse
michael@0:             if (scaledStroke.fX*(yRadius*yRadius) < (scaledStroke.fY*scaledStroke.fY)*xRadius ||
michael@0:                 scaledStroke.fY*(xRadius*xRadius) < (scaledStroke.fX*scaledStroke.fX)*yRadius) {
michael@0:                 return false;
michael@0:             }
michael@0: 
michael@0:             // this is legit only if scale & translation (which should be the case at the moment)
michael@0:             if (isStroked) {
michael@0:                 innerXRadius = xRadius - scaledStroke.fX;
michael@0:                 innerYRadius = yRadius - scaledStroke.fY;
michael@0:             }
michael@0: 
michael@0:             xRadius += scaledStroke.fX;
michael@0:             yRadius += scaledStroke.fY;
michael@0:             bounds.outset(scaledStroke.fX, scaledStroke.fY);
michael@0:         }
michael@0: 
michael@0:         isStroked = (isStroked && innerXRadius >= 0 && innerYRadius >= 0);
michael@0: 
michael@0:         GrDrawTarget::AutoReleaseGeometry geo(target, 16, 0);
michael@0:         if (!geo.succeeded()) {
michael@0:             GrPrintf("Failed to get space for vertices!\n");
michael@0:             return false;
michael@0:         }
michael@0:         EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(geo.vertices());
michael@0: 
michael@0:         GrEffectRef* effect = EllipseEdgeEffect::Create(isStroked);
michael@0:         static const int kEllipseOffsetAttrIndex = 1;
michael@0:         static const int kEllipseRadiiAttrIndex = 2;
michael@0:         drawState->addCoverageEffect(effect,
michael@0:                                      kEllipseOffsetAttrIndex, kEllipseRadiiAttrIndex)->unref();
michael@0: 
michael@0:         // Compute the reciprocals of the radii here to save time in the shader
michael@0:         SkScalar xRadRecip = SkScalarInvert(xRadius);
michael@0:         SkScalar yRadRecip = SkScalarInvert(yRadius);
michael@0:         SkScalar xInnerRadRecip = SkScalarInvert(innerXRadius);
michael@0:         SkScalar yInnerRadRecip = SkScalarInvert(innerYRadius);
michael@0: 
michael@0:         // Extend the radii out half a pixel to antialias.
michael@0:         SkScalar xOuterRadius = xRadius + SK_ScalarHalf;
michael@0:         SkScalar yOuterRadius = yRadius + SK_ScalarHalf;
michael@0: 
michael@0:         // Expand the rect so all the pixels will be captured.
michael@0:         bounds.outset(SK_ScalarHalf, SK_ScalarHalf);
michael@0: 
michael@0:         SkScalar yCoords[4] = {
michael@0:             bounds.fTop,
michael@0:             bounds.fTop + yOuterRadius,
michael@0:             bounds.fBottom - yOuterRadius,
michael@0:             bounds.fBottom
michael@0:         };
michael@0:         SkScalar yOuterOffsets[4] = {
michael@0:             yOuterRadius,
michael@0:             SK_ScalarNearlyZero, // we're using inversesqrt() in the shader, so can't be exactly 0
michael@0:             SK_ScalarNearlyZero,
michael@0:             yOuterRadius
michael@0:         };
michael@0: 
michael@0:         for (int i = 0; i < 4; ++i) {
michael@0:             verts->fPos = SkPoint::Make(bounds.fLeft, yCoords[i]);
michael@0:             verts->fOffset = SkPoint::Make(xOuterRadius, yOuterOffsets[i]);
michael@0:             verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
michael@0:             verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
michael@0:             verts++;
michael@0: 
michael@0:             verts->fPos = SkPoint::Make(bounds.fLeft + xOuterRadius, yCoords[i]);
michael@0:             verts->fOffset = SkPoint::Make(SK_ScalarNearlyZero, yOuterOffsets[i]);
michael@0:             verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
michael@0:             verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
michael@0:             verts++;
michael@0: 
michael@0:             verts->fPos = SkPoint::Make(bounds.fRight - xOuterRadius, yCoords[i]);
michael@0:             verts->fOffset = SkPoint::Make(SK_ScalarNearlyZero, yOuterOffsets[i]);
michael@0:             verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
michael@0:             verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
michael@0:             verts++;
michael@0: 
michael@0:             verts->fPos = SkPoint::Make(bounds.fRight, yCoords[i]);
michael@0:             verts->fOffset = SkPoint::Make(xOuterRadius, yOuterOffsets[i]);
michael@0:             verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
michael@0:             verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
michael@0:             verts++;
michael@0:         }
michael@0: 
michael@0:         // drop out the middle quad if we're stroked
michael@0:         int indexCnt = isStroked ? GR_ARRAY_COUNT(gRRectIndices)-6 : GR_ARRAY_COUNT(gRRectIndices);
michael@0:         target->setIndexSourceToBuffer(indexBuffer);
michael@0:         target->drawIndexed(kTriangles_GrPrimitiveType, 0, 0, 16, indexCnt, &bounds);
michael@0:     }
michael@0: 
michael@0:     return true;
michael@0: }