Add effect for ellipse clipping.
BUG=skia:2181
R=jvanverth@google.com
Author: bsalomon@google.com
Review URL: https://codereview.chromium.org/218583013
git-svn-id: http://skia.googlecode.com/svn/trunk@14024 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/effects/GrOvalEffect.cpp b/src/gpu/effects/GrOvalEffect.cpp
index 77c93e9..e033a89 100644
--- a/src/gpu/effects/GrOvalEffect.cpp
+++ b/src/gpu/effects/GrOvalEffect.cpp
@@ -73,8 +73,8 @@
}
bool CircleEffect::onIsEqual(const GrEffect& other) const {
- const CircleEffect& crre = CastEffect<CircleEffect>(other);
- return fEdgeType == crre.fEdgeType && fCenter == crre.fCenter && fRadius == crre.fRadius;
+ const CircleEffect& ce = CastEffect<CircleEffect>(other);
+ return fEdgeType == ce.fEdgeType && fCenter == ce.fCenter && fRadius == ce.fRadius;
}
//////////////////////////////////////////////////////////////////////////////
@@ -176,6 +176,190 @@
fPrevRadius = ce.getRadius();
}
}
+
+//////////////////////////////////////////////////////////////////////////////
+
+class GLEllipseEffect;
+
+class EllipseEffect : public GrEffect {
+public:
+ static GrEffectRef* Create(GrEffectEdgeType, const SkPoint& center, SkScalar rx, SkScalar ry);
+
+ virtual ~EllipseEffect() {};
+ static const char* Name() { return "Ellipse"; }
+
+ const SkPoint& getCenter() const { return fCenter; }
+ SkVector getRadii() const { return fRadii; }
+
+ GrEffectEdgeType getEdgeType() const { return fEdgeType; }
+
+ typedef GLEllipseEffect GLEffect;
+
+ virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
+
+ virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
+
+private:
+ EllipseEffect(GrEffectEdgeType, const SkPoint& center, SkScalar rx, SkScalar ry);
+
+ virtual bool onIsEqual(const GrEffect&) const SK_OVERRIDE;
+
+ SkPoint fCenter;
+ SkVector fRadii;
+ GrEffectEdgeType fEdgeType;
+
+ GR_DECLARE_EFFECT_TEST;
+
+ typedef GrEffect INHERITED;
+};
+
+GrEffectRef* EllipseEffect::Create(GrEffectEdgeType edgeType,
+ const SkPoint& center,
+ SkScalar rx,
+ SkScalar ry) {
+ SkASSERT(rx >= 0 && ry >= 0);
+ return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(EllipseEffect,
+ (edgeType, center, rx, ry))));
+}
+
+void EllipseEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
+ *validFlags = 0;
+}
+
+const GrBackendEffectFactory& EllipseEffect::getFactory() const {
+ return GrTBackendEffectFactory<EllipseEffect>::getInstance();
+}
+
+EllipseEffect::EllipseEffect(GrEffectEdgeType edgeType, const SkPoint& c, SkScalar rx, SkScalar ry)
+ : fCenter(c)
+ , fRadii(SkVector::Make(rx, ry))
+ , fEdgeType(edgeType) {
+ this->setWillReadFragmentPosition();
+}
+
+bool EllipseEffect::onIsEqual(const GrEffect& other) const {
+ const EllipseEffect& ee = CastEffect<EllipseEffect>(other);
+ return fEdgeType == ee.fEdgeType && fCenter == ee.fCenter && fRadii == ee.fRadii;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+GR_DEFINE_EFFECT_TEST(EllipseEffect);
+
+GrEffectRef* EllipseEffect::TestCreate(SkRandom* random,
+ GrContext*,
+ const GrDrawTargetCaps& caps,
+ GrTexture*[]) {
+ SkPoint center;
+ center.fX = random->nextRangeScalar(0.f, 1000.f);
+ center.fY = random->nextRangeScalar(0.f, 1000.f);
+ SkScalar rx = random->nextRangeF(0.f, 1000.f);
+ SkScalar ry = random->nextRangeF(0.f, 1000.f);
+ GrEffectEdgeType et;
+ do {
+ et = (GrEffectEdgeType)random->nextULessThan(kGrEffectEdgeTypeCnt);
+ } while (kHairlineAA_GrEffectEdgeType == et);
+ return EllipseEffect::Create(et, center, rx, ry);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+class GLEllipseEffect : public GrGLEffect {
+public:
+ GLEllipseEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
+
+ virtual void emitCode(GrGLShaderBuilder* builder,
+ const GrDrawEffect& drawEffect,
+ EffectKey key,
+ const char* outputColor,
+ const char* inputColor,
+ const TransformedCoordsArray&,
+ const TextureSamplerArray&) SK_OVERRIDE;
+
+ static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
+
+ virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
+
+private:
+ GrGLUniformManager::UniformHandle fEllipseUniform;
+ SkPoint fPrevCenter;
+ SkVector fPrevRadii;
+
+ typedef GrGLEffect INHERITED;
+};
+
+GLEllipseEffect::GLEllipseEffect(const GrBackendEffectFactory& factory,
+ const GrDrawEffect& drawEffect)
+ : INHERITED (factory) {
+ fPrevRadii.fX = -1.f;
+}
+
+void GLEllipseEffect::emitCode(GrGLShaderBuilder* builder,
+ const GrDrawEffect& drawEffect,
+ EffectKey key,
+ const char* outputColor,
+ const char* inputColor,
+ const TransformedCoordsArray&,
+ const TextureSamplerArray& samplers) {
+ const EllipseEffect& ee = drawEffect.castEffect<EllipseEffect>();
+ const char *ellipseName;
+ // The ellipse uniform is (center.x, center.y, 1 / rx^2, 1 / ry^2)
+ fEllipseUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
+ kVec4f_GrSLType,
+ "ellipse",
+ &ellipseName);
+ const char* fragmentPos = builder->fragmentPosition();
+
+ // d is the offset to the ellipse center
+ builder->fsCodeAppendf("\t\tvec2 d = %s.xy - %s.xy;\n", fragmentPos, ellipseName);
+ builder->fsCodeAppendf("\t\tvec2 Z = d * %s.zw;\n", ellipseName);
+ // implicit is the evaluation of (x/rx)^2 + (y/ry)^2 - 1.
+ builder->fsCodeAppend("\t\tfloat implicit = dot(Z, d) - 1.0;\n");
+ // grad_dot is the squared length of the gradient of the implicit.
+ builder->fsCodeAppendf("\t\tfloat grad_dot = 4.0 * dot(Z, Z);\n");
+ if (builder->ctxInfo().caps()->dropsTileOnZeroDivide()) {
+ builder->fsCodeAppend("\t\tgrad_dot = max(grad_dot, 1.0e-4);\n");
+ }
+ builder->fsCodeAppendf("\t\tfloat approx_dist = implicit * inversesqrt(grad_dot);\n");
+
+ switch (ee.getEdgeType()) {
+ case kFillAA_GrEffectEdgeType:
+ builder->fsCodeAppend("\t\tfloat alpha = clamp(0.5 - approx_dist, 0.0, 1.0);\n");
+ break;
+ case kInverseFillAA_GrEffectEdgeType:
+ builder->fsCodeAppend("\t\tfloat alpha = clamp(0.5 + approx_dist, 0.0, 1.0);\n");
+ break;
+ case kFillBW_GrEffectEdgeType:
+ builder->fsCodeAppend("\t\tfloat alpha = approx_dist > 0.0 ? 0.0 : 1.0;\n");
+ break;
+ case kInverseFillBW_GrEffectEdgeType:
+ builder->fsCodeAppend("\t\tfloat alpha = approx_dist > 0.0 ? 1.0 : 0.0;\n");
+ break;
+ case kHairlineAA_GrEffectEdgeType:
+ GrCrash("Hairline not expected here.");
+ }
+
+ builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor,
+ (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
+}
+
+GrGLEffect::EffectKey GLEllipseEffect::GenKey(const GrDrawEffect& drawEffect,
+ const GrGLCaps&) {
+ const EllipseEffect& ee = drawEffect.castEffect<EllipseEffect>();
+ return ee.getEdgeType();
+}
+
+void GLEllipseEffect::setData(const GrGLUniformManager& uman, const GrDrawEffect& drawEffect) {
+ const EllipseEffect& ee = drawEffect.castEffect<EllipseEffect>();
+ if (ee.getRadii() != fPrevRadii || ee.getCenter() != fPrevCenter) {
+ SkScalar invRXSqd = 1.f / (ee.getRadii().fX * ee.getRadii().fX);
+ SkScalar invRYSqd = 1.f / (ee.getRadii().fY * ee.getRadii().fY);
+ uman.set4f(fEllipseUniform, ee.getCenter().fX, ee.getCenter().fY, invRXSqd, invRYSqd);
+ fPrevCenter = ee.getCenter();
+ fPrevRadii = ee.getRadii();
+ }
+}
+
//////////////////////////////////////////////////////////////////////////////
GrEffectRef* GrOvalEffect::Create(GrEffectEdgeType edgeType, const SkRect& oval) {
@@ -187,6 +371,10 @@
if (SkScalarNearlyEqual(w, h)) {
w /= 2;
return CircleEffect::Create(edgeType, SkPoint::Make(oval.fLeft + w, oval.fTop + w), w);
+ } else {
+ w /= 2;
+ h /= 2;
+ return EllipseEffect::Create(edgeType, SkPoint::Make(oval.fLeft + w, oval.fTop + h), w, h);
}
return NULL;