diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/gpu/effects/GrConvexPolyEffect.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/gpu/effects/GrConvexPolyEffect.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,374 @@
+/*
+ * 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 "GrConvexPolyEffect.h"
+
+#include "gl/GrGLEffect.h"
+#include "gl/GrGLSL.h"
+#include "GrTBackendEffectFactory.h"
+
+#include "SkPath.h"
+
+//////////////////////////////////////////////////////////////////////////////
+class GLAARectEffect;
+
+class AARectEffect : public GrEffect {
+public:
+    typedef GLAARectEffect GLEffect;
+
+    const SkRect& getRect() const { return fRect; }
+
+    static const char* Name() { return "AARect"; }
+
+    static GrEffectRef* Create(GrEffectEdgeType edgeType, const SkRect& rect) {
+        return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(AARectEffect, (edgeType, rect))));
+    }
+
+    virtual void getConstantColorComponents(GrColor* color,
+                                            uint32_t* validFlags) const SK_OVERRIDE {
+        if (fRect.isEmpty()) {
+            // An empty rect will have no coverage anywhere.
+            *color = 0x00000000;
+            *validFlags = kRGBA_GrColorComponentFlags;
+        } else {
+            *validFlags = 0;
+        }
+    }
+
+    GrEffectEdgeType getEdgeType() const { return fEdgeType; }
+
+    virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
+
+private:
+    AARectEffect(GrEffectEdgeType edgeType, const SkRect& rect) : fRect(rect), fEdgeType(edgeType) {
+        this->setWillReadFragmentPosition();
+    }
+
+    virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE {
+        const AARectEffect& aare = CastEffect<AARectEffect>(other);
+        return fRect == aare.fRect;
+    }
+
+    SkRect fRect;
+    GrEffectEdgeType fEdgeType;
+
+    typedef GrEffect INHERITED;
+
+    GR_DECLARE_EFFECT_TEST;
+
+};
+
+GR_DEFINE_EFFECT_TEST(AARectEffect);
+
+GrEffectRef* AARectEffect::TestCreate(SkRandom* random,
+                                      GrContext*,
+                                      const GrDrawTargetCaps& caps,
+                                      GrTexture*[]) {
+    SkRect rect = SkRect::MakeLTRB(random->nextSScalar1(),
+                                   random->nextSScalar1(),
+                                   random->nextSScalar1(),
+                                   random->nextSScalar1());
+    GrEffectRef* effect;
+    do {
+        GrEffectEdgeType edgeType = static_cast<GrEffectEdgeType>(random->nextULessThan(
+                                                                    kGrEffectEdgeTypeCnt));
+
+        effect = AARectEffect::Create(edgeType, rect);
+    } while (NULL == effect);
+    return effect;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+class GLAARectEffect : public GrGLEffect {
+public:
+    GLAARectEffect(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   fRectUniform;
+    SkRect                              fPrevRect;
+    typedef GrGLEffect INHERITED;
+};
+
+GLAARectEffect::GLAARectEffect(const GrBackendEffectFactory& factory,
+                               const GrDrawEffect& drawEffect)
+    : INHERITED (factory) {
+    fPrevRect.fLeft = SK_ScalarNaN;
+}
+
+void GLAARectEffect::emitCode(GrGLShaderBuilder* builder,
+                              const GrDrawEffect& drawEffect,
+                              EffectKey key,
+                              const char* outputColor,
+                              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();
+    if (GrEffectEdgeTypeIsAA(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 (GrEffectEdgeTypeIsInverseFill(aare.getEdgeType())) {
+        builder->fsCodeAppend("\t\talpha = 1.0 - alpha;\n");
+    }
+    builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor,
+                           (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
+}
+
+void GLAARectEffect::setData(const GrGLUniformManager& uman, const GrDrawEffect& drawEffect) {
+    const AARectEffect& aare = drawEffect.castEffect<AARectEffect>();
+    const SkRect& rect = aare.getRect();
+    if (rect != fPrevRect) {
+        uman.set4f(fRectUniform, rect.fLeft + 0.5f, rect.fTop + 0.5f,
+                   rect.fRight - 0.5f, rect.fBottom - 0.5f);
+        fPrevRect = rect;
+    }
+}
+
+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();
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+class GrGLConvexPolyEffect : public GrGLEffect {
+public:
+    GrGLConvexPolyEffect(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   fEdgeUniform;
+    SkScalar                            fPrevEdges[3 * GrConvexPolyEffect::kMaxEdges];
+    typedef GrGLEffect INHERITED;
+};
+
+GrGLConvexPolyEffect::GrGLConvexPolyEffect(const GrBackendEffectFactory& factory,
+                                           const GrDrawEffect& drawEffect)
+    : INHERITED (factory) {
+    fPrevEdges[0] = SK_ScalarNaN;
+}
+
+void GrGLConvexPolyEffect::emitCode(GrGLShaderBuilder* builder,
+                                    const GrDrawEffect& drawEffect,
+                                    EffectKey key,
+                                    const char* outputColor,
+                                    const char* inputColor,
+                                    const TransformedCoordsArray&,
+                                    const TextureSamplerArray& samplers) {
+    const GrConvexPolyEffect& cpe = drawEffect.castEffect<GrConvexPolyEffect>();
+
+    const char *edgeArrayName;
+    fEdgeUniform = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
+                                            kVec3f_GrSLType,
+                                            "edges",
+                                            cpe.getEdgeCount(),
+                                            &edgeArrayName);
+    builder->fsCodeAppend("\t\tfloat alpha = 1.0;\n");
+    builder->fsCodeAppend("\t\tfloat edge;\n");
+    const char* fragmentPos = builder->fragmentPosition();
+    for (int i = 0; i < cpe.getEdgeCount(); ++i) {
+        builder->fsCodeAppendf("\t\tedge = dot(%s[%d], vec3(%s.x, %s.y, 1));\n",
+                               edgeArrayName, i, fragmentPos, fragmentPos);
+        if (GrEffectEdgeTypeIsAA(cpe.getEdgeType())) {
+            builder->fsCodeAppend("\t\tedge = clamp(edge, 0.0, 1.0);\n");
+        } else {
+            builder->fsCodeAppend("\t\tedge = edge >= 0.5 ? 1.0 : 0.0;\n");
+        }
+        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 (GrEffectEdgeTypeIsInverseFill(cpe.getEdgeType())) {
+        builder->fsCodeAppend("\talpha = 1.0 - alpha;\n");
+    }
+    builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
+                           (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
+}
+
+void GrGLConvexPolyEffect::setData(const GrGLUniformManager& uman, const GrDrawEffect& drawEffect) {
+    const GrConvexPolyEffect& cpe = drawEffect.castEffect<GrConvexPolyEffect>();
+    size_t byteSize = 3 * cpe.getEdgeCount() * sizeof(SkScalar);
+    if (0 != memcmp(fPrevEdges, cpe.getEdges(), byteSize)) {
+        uman.set3fv(fEdgeUniform, cpe.getEdgeCount(), cpe.getEdges());
+        memcpy(fPrevEdges, cpe.getEdges(), byteSize);
+    }
+}
+
+GrGLEffect::EffectKey GrGLConvexPolyEffect::GenKey(const GrDrawEffect& drawEffect,
+                                                   const GrGLCaps&) {
+    const GrConvexPolyEffect& cpe = drawEffect.castEffect<GrConvexPolyEffect>();
+    GR_STATIC_ASSERT(kGrEffectEdgeTypeCnt <= 8);
+    return (cpe.getEdgeCount() << 3) | cpe.getEdgeType();
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+GrEffectRef* GrConvexPolyEffect::Create(GrEffectEdgeType type, const SkPath& path, const SkVector* offset) {
+    if (kHairlineAA_GrEffectEdgeType == type) {
+        return NULL;
+    }
+    if (path.getSegmentMasks() != SkPath::kLine_SegmentMask ||
+        !path.isConvex()) {
+        return NULL;
+    }
+
+    if (path.countPoints() > kMaxEdges) {
+        return NULL;
+    }
+
+    SkPoint pts[kMaxEdges];
+    SkScalar edges[3 * kMaxEdges];
+
+    SkPath::Direction dir;
+    SkAssertResult(path.cheapComputeDirection(&dir));
+
+    SkVector t;
+    if (NULL == offset) {
+        t.set(0, 0);
+    } else {
+        t = *offset;
+    }
+
+    int count = path.getPoints(pts, kMaxEdges);
+    int n = 0;
+    for (int lastPt = count - 1, i = 0; i < count; lastPt = i++) {
+        if (pts[lastPt] != pts[i]) {
+            SkVector v = pts[i] - pts[lastPt];
+            v.normalize();
+            if (SkPath::kCCW_Direction == dir) {
+                edges[3 * n] = v.fY;
+                edges[3 * n + 1] = -v.fX;
+            } else {
+                edges[3 * n] = -v.fY;
+                edges[3 * n + 1] = v.fX;
+            }
+            SkPoint p = pts[i] + t;
+            edges[3 * n + 2] = -(edges[3 * n] * p.fX + edges[3 * n + 1] * p.fY);
+            ++n;
+        }
+    }
+    if (path.isInverseFillType()) {
+        type = GrInvertEffectEdgeType(type);
+    }
+    return Create(type, n, edges);
+}
+
+GrEffectRef* GrConvexPolyEffect::Create(GrEffectEdgeType edgeType, const SkRect& rect) {
+    if (kHairlineAA_GrEffectEdgeType == edgeType){
+        return NULL;
+    }
+    return AARectEffect::Create(edgeType, rect);
+}
+
+GrConvexPolyEffect::~GrConvexPolyEffect() {}
+
+void GrConvexPolyEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
+    *validFlags = 0;
+}
+
+const GrBackendEffectFactory& GrConvexPolyEffect::getFactory() const {
+    return GrTBackendEffectFactory<GrConvexPolyEffect>::getInstance();
+}
+
+GrConvexPolyEffect::GrConvexPolyEffect(GrEffectEdgeType edgeType, int n, const SkScalar edges[])
+    : fEdgeType(edgeType)
+    , fEdgeCount(n) {
+    // Factory function should have already ensured this.
+    SkASSERT(n <= kMaxEdges);
+    memcpy(fEdges, edges, 3 * n * sizeof(SkScalar));
+    // Outset the edges by 0.5 so that a pixel with center on an edge is 50% covered in the AA case
+    // and 100% covered in the non-AA case.
+    for (int i = 0; i < n; ++i) {
+        fEdges[3 * i + 2] += SK_ScalarHalf;
+    }
+    this->setWillReadFragmentPosition();
+}
+
+bool GrConvexPolyEffect::onIsEqual(const GrEffect& other) const {
+    const GrConvexPolyEffect& cpe = CastEffect<GrConvexPolyEffect>(other);
+    // ignore the fact that 0 == -0 and just use memcmp.
+    return (cpe.fEdgeType == fEdgeType && cpe.fEdgeCount == fEdgeCount &&
+            0 == memcmp(cpe.fEdges, fEdges, 3 * fEdgeCount * sizeof(SkScalar)));
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+GR_DEFINE_EFFECT_TEST(GrConvexPolyEffect);
+
+GrEffectRef* GrConvexPolyEffect::TestCreate(SkRandom* random,
+                                            GrContext*,
+                                            const GrDrawTargetCaps& caps,
+                                            GrTexture*[]) {
+    int count = random->nextULessThan(kMaxEdges) + 1;
+    SkScalar edges[kMaxEdges * 3];
+    for (int i = 0; i < 3 * count; ++i) {
+        edges[i] = random->nextSScalar1();
+    }
+
+    GrEffectRef* effect;
+    do {
+        GrEffectEdgeType edgeType = static_cast<GrEffectEdgeType>(
+                                        random->nextULessThan(kGrEffectEdgeTypeCnt));
+        effect = GrConvexPolyEffect::Create(edgeType, count, edges);
+    } while (NULL == effect);
+    return effect;
+}