Add effect-based clip for nine-patch SkRRects.

src/gpu/effects/GrRRectEffect.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrRRectEffect.h"
 
 #include "gl/GrGLEffect.h"
@@ skipping 359 matching lines @@
         fPrevRRect = rrect;
     }
 }
 
 //////////////////////////////////////////////////////////////////////////////
 
 class GLEllipticalRRectEffect;
 
 class EllipticalRRectEffect : public GrEffect {
 public:
-    // This effect only supports circular corner rrects where the radius is >= kRadiusMin.
+    enum RRectType {
+        kSimple_RRectType,
+        kNinePatch_RRectType,

[jvanverth1, 2014/03/12 13:37:55]

This might be worth adding to SkRRect.

[bsalomon, 2014/03/12 14:34:55]

Will do in follow-up CL

+    };
+
+    // This effect only supports rrects where the radii are >= kRadiusMin.
     static const SkScalar kRadiusMin;
 
-    static GrEffectRef* Create(GrEffectEdgeType, const SkRRect&);
+    static GrEffectRef* Create(GrEffectEdgeType, RRectType, const SkRRect&);
 
     virtual ~EllipticalRRectEffect() {};
     static const char* Name() { return "EllipticalRRect"; }
 
     const SkRRect& getRRect() const { return fRRect; }
 
+    RRectType getRRectType() const { return fRRectType; }
+
     GrEffectEdgeType getEdgeType() const { return fEdgeType; }
 
     typedef GLEllipticalRRectEffect GLEffect;
 
     virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
 
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
 
 private:
-    EllipticalRRectEffect(GrEffectEdgeType, const SkRRect&);
+    EllipticalRRectEffect(GrEffectEdgeType, RRectType, const SkRRect&);
 
     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
 
     SkRRect             fRRect;
+    RRectType           fRRectType;
     GrEffectEdgeType    fEdgeType;
 
     GR_DECLARE_EFFECT_TEST;
 
     typedef GrEffect INHERITED;
 };
 
 const SkScalar EllipticalRRectEffect::kRadiusMin = 0.5f;
 
 GrEffectRef* EllipticalRRectEffect::Create(GrEffectEdgeType edgeType,
+                                           RRectType rrType,
                                            const SkRRect& rrect) {
     SkASSERT(kFillAA_GrEffectEdgeType == edgeType || kInverseFillAA_GrEffectEdgeType == edgeType);
-    return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(EllipticalRRectEffect, (edgeType, rrect))));
+    return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(EllipticalRRectEffect, (edgeType, rrType,
+                                                                              rrect))));
 }
 
 void EllipticalRRectEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
     *validFlags = 0;
 }
 
 const GrBackendEffectFactory& EllipticalRRectEffect::getFactory() const {
     return GrTBackendEffectFactory<EllipticalRRectEffect>::getInstance();
 }
 
-EllipticalRRectEffect::EllipticalRRectEffect(GrEffectEdgeType edgeType, const SkRRect& rrect)
+EllipticalRRectEffect::EllipticalRRectEffect(GrEffectEdgeType edgeType, RRectType rrType,
+                                             const SkRRect& rrect)
     : fRRect(rrect)
+    , fRRectType(rrType)
     , fEdgeType(edgeType){
     this->setWillReadFragmentPosition();
 }
 
 bool EllipticalRRectEffect::onIsEqual(const GrEffect& other) const {
     const EllipticalRRectEffect& erre = CastEffect<EllipticalRRectEffect>(other);
+    // No need to check fRRectType as it is derived from fRRect.
     return fEdgeType == erre.fEdgeType && fRRect == erre.fRRect;
 }
 
 //////////////////////////////////////////////////////////////////////////////
 
 GR_DEFINE_EFFECT_TEST(EllipticalRRectEffect);
 
 GrEffectRef* EllipticalRRectEffect::TestCreate(SkRandom* random,
                                                GrContext*,
                                                const GrDrawTargetCaps& caps,
                                                GrTexture*[]) {
     SkScalar w = random->nextRangeScalar(20.f, 1000.f);
     SkScalar h = random->nextRangeScalar(20.f, 1000.f);
-    SkScalar rx = random->nextRangeF(kRadiusMin, 9.f);
-    SkScalar ry = random->nextRangeF(kRadiusMin, 9.f);
+    SkVector r[4];
+    r[SkRRect::kUpperLeft_Corner].fX = random->nextRangeF(kRadiusMin, 9.f);
+    // ensure at least one corner really is elliptical
+    do {
+        r[SkRRect::kUpperLeft_Corner].fY = random->nextRangeF(kRadiusMin, 9.f);
+    } while (r[SkRRect::kUpperLeft_Corner].fY == r[SkRRect::kUpperLeft_Corner].fX);
+
     SkRRect rrect;
-    rrect.setRectXY(SkRect::MakeWH(w, h), rx, ry);
+    if (random->nextBool()) {
+        // half the time create a four-radii rrect.
+        r[SkRRect::kLowerRight_Corner].fX = random->nextRangeF(kRadiusMin, 9.f);
+        r[SkRRect::kLowerRight_Corner].fY = random->nextRangeF(kRadiusMin, 9.f);
+
+        r[SkRRect::kUpperRight_Corner].fX = r[SkRRect::kLowerRight_Corner].fX;
+        r[SkRRect::kUpperRight_Corner].fY = r[SkRRect::kUpperLeft_Corner].fY;
+
+        r[SkRRect::kLowerLeft_Corner].fX = r[SkRRect::kUpperLeft_Corner].fX;
+        r[SkRRect::kLowerLeft_Corner].fY = r[SkRRect::kLowerRight_Corner].fY;
+
+        rrect.setRectRadii(SkRect::MakeWH(w, h), r);
+    } else {
+        rrect.setRectXY(SkRect::MakeWH(w, h), r[SkRRect::kUpperLeft_Corner].fX,
+                        r[SkRRect::kUpperLeft_Corner].fY);
+    }
     GrEffectRef* effect;
     do {
         GrEffectEdgeType et = (GrEffectEdgeType)random->nextULessThan(kGrEffectEdgeTypeCnt);
-        effect = EllipticalRRectEffect::Create(et, rrect);
+        effect = GrRRectEffect::Create(et, rrect);
     } while (NULL == effect);
     return effect;
 }
 
 //////////////////////////////////////////////////////////////////////////////
 
 class GLEllipticalRRectEffect : public GrGLEffect {
 public:
     GLEllipticalRRectEffect(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   fInnerRectUniform;
-    GrGLUniformManager::UniformHandle   fInvRadiusXYSqdUniform;
+    GrGLUniformManager::UniformHandle   fInvRadiiSqdUniform;
     SkRRect                             fPrevRRect;
     typedef GrGLEffect INHERITED;
 };
 
 GLEllipticalRRectEffect::GLEllipticalRRectEffect(const GrBackendEffectFactory& factory,
                              const GrDrawEffect& drawEffect)
     : INHERITED (factory) {
     fPrevRRect.setEmpty();
 }
 
 void GLEllipticalRRectEffect::emitCode(GrGLShaderBuilder* builder,
                                        const GrDrawEffect& drawEffect,
                                        EffectKey key,
                                        const char* outputColor,
                                        const char* inputColor,
                                        const TransformedCoordsArray&,
                                        const TextureSamplerArray& samplers) {
     const EllipticalRRectEffect& erre = drawEffect.castEffect<EllipticalRRectEffect>();
     const char *rectName;
-    const char *invRadiusXYSqdName;
     // The inner rect is the rrect bounds inset by the x/y radii
     fInnerRectUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                             kVec4f_GrSLType,
                                             "innerRect",
                                             &rectName);
-    fInvRadiusXYSqdUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
-                                              kVec2f_GrSLType,
-                                              "invRadiusXY",
-                                              &invRadiusXYSqdName);
     const char* fragmentPos = builder->fragmentPosition();
     // At each quarter-ellipse corner we compute a vector that is the offset of the fragment pos
     // to the ellipse center. The vector is pinned in x and y to be in the quarter-plane relevant
     // to that corner. This means that points near the interior near the rrect top edge will have
     // a vector that points straight up for both the TL left and TR corners. Computing an
     // alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
     // fragments near the other three edges will get the correct AA. Fragments in the interior of
     // the rrect will have a (0,0) vector at all four corners. So long as the radii > 0.5 they will
     // correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
     // The code below is a simplified version of the above that performs maxs on the vector
     // components before computing distances and alpha values so that only one distance computation
     // need be computed to determine the min alpha.
     builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
     builder->fsCodeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
-    builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
-    // Z is the x/y offsets divided by squared radii.
-    builder->fsCodeAppendf("\t\tvec2 Z = dxy * %s;\n", invRadiusXYSqdName);
+    switch (erre.getRRectType()) {
+        case EllipticalRRectEffect::kSimple_RRectType: {
+            const char *invRadiiXYSqdName;
+            fInvRadiiSqdUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
+                                                      kVec2f_GrSLType,
+                                                      "invRadiiXY",
+                                                      &invRadiiXYSqdName);
+            builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
+            // Z is the x/y offsets divided by squared radii.
+            builder->fsCodeAppendf("\t\tvec2 Z = dxy * %s;\n", invRadiiXYSqdName);
+            break;
+        }
+        case EllipticalRRectEffect::kNinePatch_RRectType: {
+            const char *invRadiiLTRBSqdName;
+            fInvRadiiSqdUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
+                                                      kVec4f_GrSLType,
+                                                      "invRadiiLTRB",
+                                                      &invRadiiLTRBSqdName);
+            builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
+            // Z is the x/y offsets divided by squared radii. We only care about the (at most) one
+            // corner where both the x and y offsets are positive, hence the maxes. (The inverse
+            // squared radii will always be positive.)
+            builder->fsCodeAppendf("\t\tvec2 Z = max(max(dxy0 * %s.xy, dxy1 * %s.zw), 0.0);\n",
+                                   invRadiiLTRBSqdName, invRadiiLTRBSqdName);
+            break;
+       }
+    }
     // implicit is the evaluation of (x/a)^2 + (y/b)^2 - 1.
     builder->fsCodeAppend("\t\tfloat implicit = dot(Z, dxy) - 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", fragmentPos);
     builder->fsCodeAppend("\t\tgrad_dot = max(grad_dot, 1.0e-4);\n");
     builder->fsCodeAppendf("\t\tfloat approx_dist = implicit * inversesqrt(grad_dot);\n",
-                          fragmentPos);
+                           fragmentPos);
 
     if (kFillAA_GrEffectEdgeType == erre.getEdgeType()) {
         builder->fsCodeAppend("\t\tfloat alpha = clamp(0.5 - approx_dist, 0.0, 1.0);\n");
     } else {
         builder->fsCodeAppend("\t\tfloat alpha = clamp(0.5 + approx_dist, 0.0, 1.0);\n");
     }
 
     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor,
                            (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
 }
 
 GrGLEffect::EffectKey GLEllipticalRRectEffect::GenKey(const GrDrawEffect& drawEffect,
                                                       const GrGLCaps&) {
     const EllipticalRRectEffect& erre = drawEffect.castEffect<EllipticalRRectEffect>();
-    return erre.getEdgeType();
+    GR_STATIC_ASSERT(kLast_GrEffectEdgeType < (1 << 3));
+    return erre.getRRectType() | erre.getEdgeType() << 3;
 }
 
 void GLEllipticalRRectEffect::setData(const GrGLUniformManager& uman,
                                       const GrDrawEffect& drawEffect) {
     const EllipticalRRectEffect& erre = drawEffect.castEffect<EllipticalRRectEffect>();
     const SkRRect& rrect = erre.getRRect();
     if (rrect != fPrevRRect) {
         SkRect rect = rrect.getBounds();
-        SkASSERT(rrect.isSimple());
-        const SkVector& radius = rrect.getSimpleRadii();
-        SkASSERT(radius.fX >= EllipticalRRectEffect::kRadiusMin);
-        SkASSERT(radius.fY >= EllipticalRRectEffect::kRadiusMin);
-        rect.inset(radius.fX, radius.fY);
+        const SkVector& r0 = rrect.radii(SkRRect::kUpperLeft_Corner);
+        SkASSERT(r0.fX >= EllipticalRRectEffect::kRadiusMin);
+        SkASSERT(r0.fY >= EllipticalRRectEffect::kRadiusMin);
+        switch (erre.getRRectType()) {
+            case EllipticalRRectEffect::kSimple_RRectType:
+                rect.inset(r0.fX, r0.fY);
+                uman.set2f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),

[jvanverth1, 2014/03/12 13:37:55]

Use SkScalarInvert or SkScalarFastInvert?

[bsalomon, 2014/03/12 14:34:55]

I checked with Mike and he sez using SkScalarInvert doesn't add any value (now
that we no longer support scalar=fixed)

+                                                1.f / (r0.fY * r0.fY));
+                break;
+            case EllipticalRRectEffect::kNinePatch_RRectType: {
+                const SkVector& r1 = rrect.radii(SkRRect::kLowerRight_Corner);
+                SkASSERT(r1.fX >= EllipticalRRectEffect::kRadiusMin);
+                SkASSERT(r1.fY >= EllipticalRRectEffect::kRadiusMin);
+                rect.fLeft += r0.fX;
+                rect.fTop += r0.fY;
+                rect.fRight -= r1.fX;
+                rect.fBottom -= r1.fY;
+                uman.set4f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
+                                                1.f / (r0.fY * r0.fY),
+                                                1.f / (r1.fX * r1.fX),
+                                                1.f / (r1.fY * r1.fY));
+                break;
+            }
+        }
         uman.set4f(fInnerRectUniform, rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
-        uman.set2f(fInvRadiusXYSqdUniform, 1.f / (radius.fX * radius.fX),
-                                           1.f / (radius.fY * radius.fY));
         fPrevRRect = rrect;
     }
 }
 
 //////////////////////////////////////////////////////////////////////////////
 
 GrEffectRef* GrRRectEffect::Create(GrEffectEdgeType edgeType, const SkRRect& rrect) {
     if (kFillAA_GrEffectEdgeType != edgeType && kInverseFillAA_GrEffectEdgeType != edgeType) {
         return NULL;
     }
     uint32_t cornerFlags;
     if (rrect.isSimple()) {
         if (rrect.getSimpleRadii().fX == rrect.getSimpleRadii().fY) {
             if (rrect.getSimpleRadii().fX < CircularRRectEffect::kRadiusMin) {
                 return NULL;
             }
             cornerFlags = CircularRRectEffect::kAll_CornerFlags;
         } else {
             if (rrect.getSimpleRadii().fX < EllipticalRRectEffect::kRadiusMin ||
                 rrect.getSimpleRadii().fY < EllipticalRRectEffect::kRadiusMin) {
                 return NULL;
             }
-            return EllipticalRRectEffect::Create(edgeType, rrect);
+            return EllipticalRRectEffect::Create(edgeType,
+                                                 EllipticalRRectEffect::kSimple_RRectType, rrect);
         }
     } else if (rrect.isComplex()) {
         // Check for the "tab" cases - two adjacent circular corners and two square corners.
         SkScalar radius = 0;
         cornerFlags = 0;
         for (int c = 0; c < 4; ++c) {
             const SkVector& r = rrect.radii((SkRRect::Corner)c);
             SkASSERT((0 == r.fX) == (0 == r.fY));
             if (0 == r.fX) {
                 continue;
             }
             if (r.fX != r.fY) {
-                return NULL;
+                cornerFlags = -1;

[jvanverth1, 2014/03/12 13:37:55]

This seems a little hacky, but I don't have a better suggestion.

[bsalomon, 2014/03/12 14:34:55]

yup :)

+                break;
             }
             if (!cornerFlags) {
                 radius = r.fX;
                 if (radius < CircularRRectEffect::kRadiusMin) {
-                    return NULL;
+                    cornerFlags = -1;
+                    break;
                 }
                 cornerFlags = 1 << c;
             } else {
                 if (r.fX != radius) {
-                    return NULL;
+                   cornerFlags = -1;
+                   break;
                 }
                 cornerFlags |= 1 << c;
             }
         }
 
         switch (cornerFlags) {
             case CircularRRectEffect::kTopLeft_CornerFlag:
             case CircularRRectEffect::kTopRight_CornerFlag:
             case CircularRRectEffect::kBottomRight_CornerFlag:
             case CircularRRectEffect::kBottomLeft_CornerFlag:
             case CircularRRectEffect::kLeft_CornerFlags:
             case CircularRRectEffect::kTop_CornerFlags:
             case CircularRRectEffect::kRight_CornerFlags:
             case CircularRRectEffect::kBottom_CornerFlags:
             case CircularRRectEffect::kAll_CornerFlags:
                 break;
             default:
+                if (rrect.isNinePatch()) {
+                    const SkVector& r0 = rrect.radii(SkRRect::kUpperLeft_Corner);
+                    const SkVector& r1 = rrect.radii(SkRRect::kLowerRight_Corner);
+                    if (r0.fX >= EllipticalRRectEffect::kRadiusMin &&
+                        r0.fY >= EllipticalRRectEffect::kRadiusMin &&
+                        r1.fX >= EllipticalRRectEffect::kRadiusMin &&
+                        r1.fY >= EllipticalRRectEffect::kRadiusMin) {
+                        return EllipticalRRectEffect::Create(edgeType,
+                                                        EllipticalRRectEffect::kNinePatch_RRectType,
+                                                        rrect);
+                    }
+                }
                 return NULL;
         }
     } else {
         return NULL;
     }
     return CircularRRectEffect::Create(edgeType, cornerFlags, rrect);
 }