Make GrConvexPolyEffect support inverse fills and non-AA rects

BUG=skia:2151
R=robertphillips@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/183833003

git-svn-id: http://skia.googlecode.com/svn/trunk@13621 2bbb7eff-a529-9590-31e7-b0007b416f81

4 files changed, 94 insertions, 57 deletions

diff --git a/gm/convexpolyeffect.cpp b/gm/convexpolyeffect.cpp
index 2632bd4186..9142ca9cbd 100644
--- a/gm/convexpolyeffect.cpp
+++ b/gm/convexpolyeffect.cpp
@@ -44,7 +44,7 @@ protected:
     }
 
     virtual SkISize onISize() SK_OVERRIDE {
-        return make_isize(475, 800);
+        return make_isize(720, 800);
     }
 
     virtual uint32_t onGetFlags() const SK_OVERRIDE {
@@ -100,7 +100,6 @@ protected:
         fRects.addToTail(SkRect::MakeLTRB(5.05f, .55f, 5.45f, .85f));
         // inverted in x and y
         fRects.addToTail(SkRect::MakeLTRB(100.f, 50.5f, 5.f, 0.5f));
-
     }
 
     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
@@ -174,55 +173,58 @@ protected:
             y += SkScalarCeilToScalar(path->getBounds().height() + 20.f);
         }
 
-        // Draw rects. We only have specialized effect code for the AA case, so don't do non-AA.
         for (SkTLList<SkRect>::Iter iter(fRects, SkTLList<SkRect>::Iter::kHead_IterStart);
              NULL != iter.get();
              iter.next()) {
 
             SkScalar x = 0;
 
-            GrTestTarget tt;
-            context->getTestTarget(&tt);
-            if (NULL == tt.target()) {
-                SkDEBUGFAIL("Couldn't get Gr test target.");
-                return;
-            }
-
-            SkRect rect = *iter.get();
-            rect.offset(x, y);
-            SkAutoTUnref<GrEffectRef> effect(GrConvexPolyEffect::CreateForAAFillRect(rect));
-            if (!effect) {
-                SkDEBUGFAIL("Couldn't create convex poly effect.");
-                return;
-            }
+            for (int et = 0; et < GrConvexPolyEffect::kEdgeTypeCnt; ++et) {
+                GrTestTarget tt;
+                context->getTestTarget(&tt);
+                if (NULL == tt.target()) {
+                    SkDEBUGFAIL("Couldn't get Gr test target.");
+                    return;
+                }
+                SkRect rect = *iter.get();
+                rect.offset(x, y);
+                GrConvexPolyEffect::EdgeType edgeType = (GrConvexPolyEffect::EdgeType) et;
+                SkAutoTUnref<GrEffectRef> effect(GrConvexPolyEffect::Create(edgeType, rect));
+                if (!effect) {
+                    SkDEBUGFAIL("Couldn't create convex poly effect.");
+                    return;
+                }
 
-            GrDrawState* drawState = tt.target()->drawState();
-            drawState->setVertexAttribs<kAttribs>(SK_ARRAY_COUNT(kAttribs));
-            drawState->addCoverageEffect(effect, 1);
-            drawState->setIdentityViewMatrix();
-            drawState->setRenderTarget(rt);
-            drawState->setColor(0xff000000);
+                GrDrawState* drawState = tt.target()->drawState();
+                drawState->setVertexAttribs<kAttribs>(SK_ARRAY_COUNT(kAttribs));
+                drawState->addCoverageEffect(effect, 1);
+                drawState->setIdentityViewMatrix();
+                drawState->setRenderTarget(rt);
+                drawState->setColor(0xff000000);
 
-            SkPoint verts[4];
-            SkRect bounds = rect;
-            bounds.outset(5.f, 5.f);
-            bounds.toQuad(verts);
+                SkPoint verts[4];
+                SkRect bounds = rect;
+                bounds.outset(5.f, 5.f);
+                bounds.toQuad(verts);
 
-            tt.target()->setVertexSourceToArray(verts, 4);
-            tt.target()->setIndexSourceToBuffer(context->getQuadIndexBuffer());
-            tt.target()->drawIndexed(kTriangleFan_GrPrimitiveType, 0, 0, 4, 6);
+                tt.target()->setVertexSourceToArray(verts, 4);
+                tt.target()->setIndexSourceToBuffer(context->getQuadIndexBuffer());
+                tt.target()->drawIndexed(kTriangleFan_GrPrimitiveType, 0, 0, 4, 6);
 
-            x += SkScalarCeilToScalar(rect.width() + 10.f);
+                x += SkScalarCeilToScalar(rect.width() + 10.f);
+            }
 
-            // Draw AA rect using normal API for reference
+            // Draw rect without and with AA using normal API for reference
             canvas->save();
             canvas->translate(x, y);
             SkPaint paint;
+            canvas->drawRect(*iter.get(), paint);
+            x += SkScalarCeilToScalar(iter.get()->width() + 10.f);
             paint.setAntiAlias(true);
             canvas->drawRect(*iter.get(), paint);
             canvas->restore();
 
-            y += SkScalarCeilToScalar(rect.height() + 20.f);
+            y += SkScalarCeilToScalar(iter.get()->height() + 20.f);
         }
     }
 
diff --git a/src/gpu/GrClipMaskManager.cpp b/src/gpu/GrClipMaskManager.cpp
index b637bd6c7a..90106fa7e0 100644
--- a/src/gpu/GrClipMaskManager.cpp
+++ b/src/gpu/GrClipMaskManager.cpp
@@ -200,7 +200,7 @@ bool GrClipMaskManager::setupClipping(const GrClipData* clipDataIn,
             SkVector offset = { SkIntToScalar(-clipDataIn->fOrigin.fX),
                                 SkIntToScalar(-clipDataIn->fOrigin.fY) };
             rect.offset(offset);
-            effect.reset(GrConvexPolyEffect::CreateForAAFillRect(rect));
+            effect.reset(GrConvexPolyEffect::Create(GrConvexPolyEffect::kFillAA_EdgeType, rect));
             // This should never fail.
             SkASSERT(effect);
         }
diff --git a/src/gpu/effects/GrConvexPolyEffect.cpp b/src/gpu/effects/GrConvexPolyEffect.cpp
index bbfa3bb82c..baad92837c 100644
--- a/src/gpu/effects/GrConvexPolyEffect.cpp
+++ b/src/gpu/effects/GrConvexPolyEffect.cpp
@@ -19,13 +19,14 @@ class GLAARectEffect;
 class AARectEffect : public GrEffect {
 public:
     typedef GLAARectEffect GLEffect;
+    typedef GrConvexPolyEffect::EdgeType EdgeType;
 
     const SkRect& getRect() const { return fRect; }
 
     static const char* Name() { return "AARect"; }
 
-    static GrEffectRef* Create(const SkRect& rect) {
-        return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(AARectEffect, (rect))));
+    static GrEffectRef* Create(EdgeType edgeType, const SkRect& rect) {
+        return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(AARectEffect, (edgeType, rect))));
     }
 
     virtual void getConstantColorComponents(GrColor* color,
@@ -39,10 +40,12 @@ public:
         }
     }
 
+    GrConvexPolyEffect::EdgeType getEdgeType() const { return fEdgeType; }
+
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
 
 private:
-    AARectEffect(const SkRect& rect) : fRect(rect) {
+    AARectEffect(EdgeType edgeType, const SkRect& rect) : fRect(rect), fEdgeType(edgeType) {
         this->setWillReadFragmentPosition();
     }
 
@@ -52,6 +55,8 @@ private:
     }
 
     SkRect fRect;
+    EdgeType fEdgeType;
+
     typedef GrEffect INHERITED;
 
     GR_DECLARE_EFFECT_TEST;
@@ -64,11 +69,14 @@ GrEffectRef* AARectEffect::TestCreate(SkRandom* random,
                                       GrContext*,
                                       const GrDrawTargetCaps& caps,
                                       GrTexture*[]) {
+    EdgeType edgeType = static_cast<EdgeType>(
+                                    random->nextULessThan(GrConvexPolyEffect::kEdgeTypeCnt));
+
     SkRect rect = SkRect::MakeLTRB(random->nextSScalar1(),
                                    random->nextSScalar1(),
                                    random->nextSScalar1(),
                                    random->nextSScalar1());
-    return AARectEffect::Create(rect);
+    return AARectEffect::Create(edgeType, rect);
 }
 
 //////////////////////////////////////////////////////////////////////////////
@@ -85,7 +93,7 @@ public:
                           const TransformedCoordsArray&,
                           const TextureSamplerArray&) SK_OVERRIDE;
 
-    static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&) { return 0; }
+    static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
 
     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
 
@@ -108,23 +116,39 @@ void GLAARectEffect::emitCode(GrGLShaderBuilder* builder,
                               const char* inputColor,
                               const TransformedCoordsArray&,
                               const TextureSamplerArray& samplers) {
+    const AARectEffect& aare = drawEffect.castEffect<AARectEffect>();
     const char *rectName;
+    // The rect uniform's xyzw refer to (left + 0.5, top + 0.5, right - 0.5, bottom - 0.5),
+    // respectively.
     fRectUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                        kVec4f_GrSLType,
                                        "rect",
                                        &rectName);
     const char* fragmentPos = builder->fragmentPosition();
-    // The rect uniform's xyzw refer to (left + 0.5, top + 0.5, right - 0.5, bottom - 0.5),
-    // respectively. The amount of coverage removed in x and y by the edges is computed as a pair of
-    // negative numbers, xSub and ySub.
-    builder->fsCodeAppend("\t\tfloat xSub, ySub;\n");
-    builder->fsCodeAppendf("\t\txSub = min(%s.x - %s.x, 0.0);\n", fragmentPos, rectName);
-    builder->fsCodeAppendf("\t\txSub += min(%s.z - %s.x, 0.0);\n", rectName, fragmentPos);
-    builder->fsCodeAppendf("\t\tySub = min(%s.y - %s.y, 0.0);\n", fragmentPos, rectName);
-    builder->fsCodeAppendf("\t\tySub += min(%s.w - %s.y, 0.0);\n", rectName, fragmentPos);
-    // Now compute coverage in x and y and multiply them to get the fraction of the pixel covered.
-    builder->fsCodeAppendf("\t\tfloat alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));\n");
+    if (GrConvexPolyEffect::kFillAA_EdgeType == aare.getEdgeType() ||
+        GrConvexPolyEffect::kInverseFillAA_EdgeType == aare.getEdgeType()) {
+        // The amount of coverage removed in x and y by the edges is computed as a pair of negative
+        // numbers, xSub and ySub.
+        builder->fsCodeAppend("\t\tfloat xSub, ySub;\n");
+        builder->fsCodeAppendf("\t\txSub = min(%s.x - %s.x, 0.0);\n", fragmentPos, rectName);
+        builder->fsCodeAppendf("\t\txSub += min(%s.z - %s.x, 0.0);\n", rectName, fragmentPos);
+        builder->fsCodeAppendf("\t\tySub = min(%s.y - %s.y, 0.0);\n", fragmentPos, rectName);
+        builder->fsCodeAppendf("\t\tySub += min(%s.w - %s.y, 0.0);\n", rectName, fragmentPos);
+        // Now compute coverage in x and y and multiply them to get the fraction of the pixel
+        // covered.
+        builder->fsCodeAppendf("\t\tfloat alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));\n");
+    } else {
+        builder->fsCodeAppendf("\t\tfloat alpha = 1.0;\n");
+        builder->fsCodeAppendf("\t\talpha *= (%s.x - %s.x) > -0.5 ? 1.0 : 0.0;\n", fragmentPos, rectName);
+        builder->fsCodeAppendf("\t\talpha *= (%s.z - %s.x) > -0.5 ? 1.0 : 0.0;\n", rectName, fragmentPos);
+        builder->fsCodeAppendf("\t\talpha *= (%s.y - %s.y) > 0.5 ? 1.0 : 0.0;\n", fragmentPos, rectName);
+        builder->fsCodeAppendf("\t\talpha *= (%s.w - %s.y) > 0.5 ? 1.0 : 0.0;\n", rectName, fragmentPos);
+    }
 
+    if (GrConvexPolyEffect::kInverseFillAA_EdgeType == aare.getEdgeType() ||
+        GrConvexPolyEffect::kInverseFillNoAA_EdgeType == aare.getEdgeType()) {
+        builder->fsCodeAppend("\t\talpha = 1.0 - alpha;\n");
+    }
     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor,
                            (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
 }
@@ -139,6 +163,11 @@ void GLAARectEffect::setData(const GrGLUniformManager& uman, const GrDrawEffect&
     }
 }
 
+GrGLEffect::EffectKey GLAARectEffect::GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
+    const AARectEffect& aare = drawEffect.castEffect<AARectEffect>();
+    return aare.getEdgeType();
+}
+
 const GrBackendEffectFactory& AARectEffect::getFactory() const {
     return GrTBackendEffectFactory<AARectEffect>::getInstance();
 }
@@ -196,20 +225,26 @@ void GrGLConvexPolyEffect::emitCode(GrGLShaderBuilder* builder,
                                edgeArrayName, i, fragmentPos, fragmentPos);
         switch (cpe.getEdgeType()) {
             case GrConvexPolyEffect::kFillAA_EdgeType:
+            case GrConvexPolyEffect::kInverseFillAA_EdgeType: // inverse handled at the end
                 builder->fsCodeAppend("\t\tedge = clamp(edge, 0.0, 1.0);\n");
-                builder->fsCodeAppend("\t\talpha *= edge;\n");
                 break;
             case GrConvexPolyEffect::kFillNoAA_EdgeType:
+            case GrConvexPolyEffect::kInverseFillNoAA_EdgeType: // inverse handled at the end
                 builder->fsCodeAppend("\t\tedge = edge >= 0.5 ? 1.0 : 0.0;\n");
-                builder->fsCodeAppend("\t\talpha *= edge;\n");
                 break;
         }
+        builder->fsCodeAppend("\t\talpha *= edge;\n");
     }
 
     // Woe is me. See skbug.com/2149.
     if (kTegra2_GrGLRenderer == builder->ctxInfo().renderer()) {
         builder->fsCodeAppend("\t\tif (-1.0 == alpha) {\n\t\t\tdiscard;\n\t\t}\n");
     }
+
+    if (GrConvexPolyEffect::kInverseFillAA_EdgeType == cpe.getEdgeType() ||
+        GrConvexPolyEffect::kInverseFillNoAA_EdgeType == cpe.getEdgeType() ) {
+        builder->fsCodeAppend("\talpha = 1.0 - alpha;\n");
+    }
     builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
                            (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
 }
@@ -277,8 +312,8 @@ GrEffectRef* GrConvexPolyEffect::Create(EdgeType type, const SkPath& path, const
     return Create(type, n, edges);
 }
 
-GrEffectRef* GrConvexPolyEffect::CreateForAAFillRect(const SkRect& rect) {
-    return AARectEffect::Create(rect);
+GrEffectRef* GrConvexPolyEffect::Create(EdgeType edgeType, const SkRect& rect) {
+    return AARectEffect::Create(edgeType, rect);
 }
 
 GrConvexPolyEffect::~GrConvexPolyEffect() {}
diff --git a/src/gpu/effects/GrConvexPolyEffect.h b/src/gpu/effects/GrConvexPolyEffect.h
index c712eb3af8..ab9d313c16 100644
--- a/src/gpu/effects/GrConvexPolyEffect.h
+++ b/src/gpu/effects/GrConvexPolyEffect.h
@@ -21,13 +21,13 @@ class SkPath;
  */
 class GrConvexPolyEffect : public GrEffect {
 public:
-    /** This could be expanded to include a AA hairline mode. If so, unify with GrBezierEffect's
-        enum. */
     enum EdgeType {
         kFillNoAA_EdgeType,
         kFillAA_EdgeType,
+        kInverseFillNoAA_EdgeType,
+        kInverseFillAA_EdgeType,
 
-        kLastEdgeType = kFillAA_EdgeType,
+        kLastEdgeType = kInverseFillAA_EdgeType,
     };
 
     enum {
@@ -64,7 +64,7 @@ public:
     /**
      * Creates an effect that fills inside the rect with AA edges..
      */
-    static GrEffectRef* CreateForAAFillRect(const SkRect&);
+    static GrEffectRef* Create(EdgeType, const SkRect&);
 
     virtual ~GrConvexPolyEffect();