Added GrAAFlatteningConvexPathRenderer.

This is an alternate version of GrAAConvexPathRenderer which handles
curves by first flattening them to straight lines.

BUG=skia:

Review URL: https://codereview.chromium.org/1158803002

gyp/gpu.gypi

@@ -57,6 +57,8 @@
       '<(skia_src_path)/gpu/GrAAHairLinePathRenderer.h',
       '<(skia_src_path)/gpu/GrAAConvexPathRenderer.cpp',
       '<(skia_src_path)/gpu/GrAAConvexPathRenderer.h',
+      '<(skia_src_path)/gpu/GrAALinearizingConvexPathRenderer.cpp',
+      '<(skia_src_path)/gpu/GrAALinearizingConvexPathRenderer.h',
       '<(skia_src_path)/gpu/GrAAConvexTessellator.cpp',
       '<(skia_src_path)/gpu/GrAAConvexTessellator.h',
       '<(skia_src_path)/gpu/GrAADistanceFieldPathRenderer.cpp',

src/gpu/GrAAConvexTessellator.cpp

@@ -10,6 +10,7 @@
 #include "SkPath.h"
 #include "SkPoint.h"
 #include "SkString.h"
+#include "GrPathUtils.h"
 
 // Next steps:
 //  use in AAConvexPathRenderer
@@ -51,13 +52,15 @@ static SkScalar abs_dist_from_line(const SkPoint& p0, const SkVector& v, const S
 
 int GrAAConvexTessellator::addPt(const SkPoint& pt,
                                  SkScalar depth,
-                                 bool movable) {
+                                 bool movable,
+                                 bool isCurve) {
     this->validate();
 
     int index = fPts.count();
     *fPts.push() = pt;
     *fDepths.push() = depth;
     *fMovable.push() = movable;
+    *fIsCurve.push() = isCurve;
 
     this->validate();
     return index;
@@ -236,7 +239,6 @@ bool GrAAConvexTessellator::computePtAlongBisector(int startIdx,
 }
 
 bool GrAAConvexTessellator::extractFromPath(const SkMatrix& m, const SkPath& path) {
-    SkASSERT(SkPath::kLine_SegmentMask == path.getSegmentMasks());
     SkASSERT(SkPath::kConvex_Convexity == path.getConvexity());
 
     // Outer ring: 3*numPts
@@ -250,7 +252,8 @@ bool GrAAConvexTessellator::extractFromPath(const SkMatrix& m, const SkPath& pat
 
     fNorms.setReserve(path.countPoints());
 
-    SkScalar minCross = SK_ScalarMax, maxCross = -SK_ScalarMax;
+    SkDEBUGCODE(fMinCross = SK_ScalarMax;)
+    SkDEBUGCODE(fMaxCross = -SK_ScalarMax;)
 
     // TODO: is there a faster way to extract the points from the path? Perhaps
     // get all the points via a new entry point, transform them all in bulk
@@ -261,38 +264,16 @@ bool GrAAConvexTessellator::extractFromPath(const SkMatrix& m, const SkPath& pat
     while ((verb = iter.next(pts)) != SkPath::kDone_Verb) {
         switch (verb) {
             case SkPath::kLine_Verb:
-                m.mapPoints(&pts[1], 1);
+                this->lineTo(m, pts[1], false);
-                if (this->numPts() > 0 && duplicate_pt(pts[1], this->lastPoint())) {
-                    continue;
-                }
-
-                SkASSERT(fPts.count() <= 1 || fPts.count() == fNorms.count()+1);
-                if (this->numPts() >= 2 && 
-                    abs_dist_from_line(fPts.top(), fNorms.top(), pts[1]) < kClose) {
-                    // The old last point is on the line from the second to last to the new point
-                    this->popLastPt();
-                    fNorms.pop();
-                }
-
-                this->addPt(pts[1], 0.0f, false);
-                if (this->numPts() > 1) {
-                    *fNorms.push() = fPts.top() - fPts[fPts.count()-2];
-                    SkDEBUGCODE(SkScalar len =) SkPoint::Normalize(&fNorms.top());
-                    SkASSERT(len > 0.0f);
-                    SkASSERT(SkScalarNearlyEqual(1.0f, fNorms.top().length()));
-                }
-
-                if (this->numPts() >= 3) {
-                    int cur = this->numPts()-1;
-                    SkScalar cross = SkPoint::CrossProduct(fNorms[cur-1], fNorms[cur-2]);
-                    maxCross = SkTMax(maxCross, cross);
-                    minCross = SkTMin(minCross, cross);
-                }
                 break;
             case SkPath::kQuad_Verb:
-            case SkPath::kConic_Verb:
+                this->quadTo(m, pts);
+                break;
             case SkPath::kCubic_Verb:
-                SkASSERT(false);
+                this->cubicTo(m, pts);
+                break;
+            case SkPath::kConic_Verb:
+                this->conicTo(m, pts, iter.conicWeight());
                 break;
             case SkPath::kMove_Verb:
             case SkPath::kClose_Verb:
@@ -342,16 +323,14 @@ bool GrAAConvexTessellator::extractFromPath(const SkMatrix& m, const SkPath& pat
         return false;
     }
 
-    // Check the cross produce of the final trio
+    // Check the cross product of the final trio
     SkScalar cross = SkPoint::CrossProduct(fNorms[0], fNorms.top());
-    maxCross = SkTMax(maxCross, cross);
+    SkDEBUGCODE(fMaxCross = SkTMax(fMaxCross, cross));
-    minCross = SkTMin(minCross, cross);
+    SkDEBUGCODE(fMinCross = SkTMin(fMinCross, cross));
-
+    SkASSERT((fMaxCross >= 0.0f) == (fMinCross >= 0.0f));
-    if (maxCross > 0.0f) {
+    if (cross > 0.0f) {
-        SkASSERT(minCross >= 0.0f);
         fSide = SkPoint::kRight_Side;
     } else {
-        SkASSERT(minCross <= 0.0f);
         fSide = SkPoint::kLeft_Side;
     }
 
@@ -404,69 +383,109 @@ void GrAAConvexTessellator::createOuterRing() {
 
     const int numPts = fPts.count();
 
-    // For each vertex of the original polygon we add three points to the 
-    // outset polygon - one extending perpendicular to each impinging edge
-    // and one along the bisector. Two triangles are added for each corner
-    // and two are added along each edge.
     int prev = numPts - 1;
     int lastPerpIdx = -1, firstPerpIdx = -1, newIdx0, newIdx1, newIdx2;
     for (int cur = 0; cur < numPts; ++cur) {
-        // The perpendicular point for the last edge
+        if (fIsCurve[cur]) {
-        SkPoint temp = fNorms[prev];
+            // Inside a curve, we assume that the curvature is shallow enough (due to tesselation) 
-        temp.scale(fTargetDepth);
+            // that we only need one corner point. Mathematically, the distance the corner point 
-        temp += fPts[cur];
+            // gets shifted out should depend on the angle between the two line segments (as in 
+            // mitering), but again due to tesselation we assume that this angle is small and 
+            // therefore the correction factor is negligible and we do not bother with it.
 
-        // We know it isn't a duplicate of the prior point (since it and this
+            // The bisector outset point
-        // one are just perpendicular offsets from the non-merged polygon points)
+            SkPoint temp = fBisectors[cur];
-        newIdx0 = this->addPt(temp, -fTargetDepth, false);
+            temp.scale(-fTargetDepth);  // the bisectors point in
+            temp += fPts[cur];
 
-        // The bisector outset point
+            // double-check our "sufficiently flat" assumption; we want the bisector point to be
-        temp = fBisectors[cur];
+            // close to the normal point.
-        temp.scale(-fTargetDepth);  // the bisectors point in
+            #define kFlatnessTolerance 1.0f
-        temp += fPts[cur];
+            SkDEBUGCODE(SkPoint prevNormal = fNorms[prev];)
+            SkDEBUGCODE(prevNormal.scale(fTargetDepth);)
+            SkDEBUGCODE(prevNormal += fPts[cur];)
+            SkASSERT((temp - prevNormal).length() < kFlatnessTolerance);
 
-        // For very shallow angles all the corner points could fuse
+            newIdx1 = this->addPt(temp, -fTargetDepth, false, true);
-        if (duplicate_pt(temp, this->point(newIdx0))) {
+
-            newIdx1 = newIdx0;
+            if (0 == cur) {
-        } else {
+                // Store the index of the first perpendicular point to finish up
-            newIdx1 = this->addPt(temp, -fTargetDepth, false);
+                firstPerpIdx = newIdx1;
+                SkASSERT(-1 == lastPerpIdx);
+            } else {
+                // The triangles for the previous edge
+                this->addTri(prev, newIdx1, cur);
+                this->addTri(prev, lastPerpIdx, newIdx1);
+            }
+
+            prev = cur;
+            // Track the last perpendicular outset point so we can construct the
+            // trailing edge triangles.
+            lastPerpIdx = newIdx1;
         }
+        else {
+            // For each vertex of the original polygon we add three points to the 
+            // outset polygon - one extending perpendicular to each impinging edge
+            // and one along the bisector. Two triangles are added for each corner
+            // and two are added along each edge.
 
-        // The perpendicular point for the next edge.
+            // The perpendicular point for the last edge
-        temp = fNorms[cur];
+            SkPoint temp = fNorms[prev];
-        temp.scale(fTargetDepth);
+            temp.scale(fTargetDepth);
-        temp += fPts[cur];
+            temp += fPts[cur];
 
-        // For very shallow angles all the corner points could fuse.
+            // We know it isn't a duplicate of the prior point (since it and this
-        if (duplicate_pt(temp, this->point(newIdx1))) {
+            // one are just perpendicular offsets from the non-merged polygon points)
-            newIdx2 = newIdx1;
+            newIdx0 = this->addPt(temp, -fTargetDepth, false, false);
-        } else {
+
-            newIdx2 = this->addPt(temp, -fTargetDepth, false);
+            // The bisector outset point
+            temp = fBisectors[cur];
+            temp.scale(-fTargetDepth);  // the bisectors point in
+            temp += fPts[cur];
+
+            // For very shallow angles all the corner points could fuse
+            if (duplicate_pt(temp, this->point(newIdx0))) {
+                newIdx1 = newIdx0;
+            } else {
+                newIdx1 = this->addPt(temp, -fTargetDepth, false, false);
+            }
+
+            // The perpendicular point for the next edge.
+            temp = fNorms[cur];
+            temp.scale(fTargetDepth);
+            temp += fPts[cur];
+
+            // For very shallow angles all the corner points could fuse.
+            if (duplicate_pt(temp, this->point(newIdx1))) {
+                newIdx2 = newIdx1;
+            } else {
+                newIdx2 = this->addPt(temp, -fTargetDepth, false, false);
+            }
+
+            if (0 == cur) {
+                // Store the index of the first perpendicular point to finish up
+                firstPerpIdx = newIdx0;
+                SkASSERT(-1 == lastPerpIdx);
+            } else {
+                // The triangles for the previous edge
+                this->addTri(prev, newIdx0, cur);
+                this->addTri(prev, lastPerpIdx, newIdx0);
+            }
+
+            // The two triangles for the corner
+            this->addTri(cur, newIdx0, newIdx1);
+            this->addTri(cur, newIdx1, newIdx2);
+
+            prev = cur;
+            // Track the last perpendicular outset point so we can construct the
+            // trailing edge triangles.
+            lastPerpIdx = newIdx2;
         }
-
-        if (0 == cur) {
-            // Store the index of the first perpendicular point to finish up
-            firstPerpIdx = newIdx0;
-            SkASSERT(-1 == lastPerpIdx);
-        } else {
-            // The triangles for the previous edge
-            this->addTri(prev, newIdx0, cur);
-            this->addTri(prev, lastPerpIdx, newIdx0);
-        }
-
-        // The two triangles for the corner
-        this->addTri(cur, newIdx0, newIdx1);
-        this->addTri(cur, newIdx1, newIdx2);
-
-        prev = cur;
-        // Track the last perpendicular outset point so we can construct the
-        // trailing edge triangles.
-        lastPerpIdx = newIdx2;
     }
 
     // pick up the final edge rect
-    this->addTri(numPts-1, firstPerpIdx, 0);
+    this->addTri(numPts - 1, firstPerpIdx, 0);
-    this->addTri(numPts-1, lastPerpIdx, firstPerpIdx);
+    this->addTri(numPts - 1, lastPerpIdx, firstPerpIdx);
 
     this->validate();
 }
@@ -592,7 +611,7 @@ bool GrAAConvexTessellator::createInsetRing(const Ring& lastRing, Ring* nextRing
             // if the originating index is still valid then this point wasn't 
             // fused (and is thus movable)
             newIdx = this->addPt(fCandidateVerts.point(i), depth,
-                                 fCandidateVerts.originatingIdx(i) != -1);
+                                 fCandidateVerts.originatingIdx(i) != -1, false);
         } else {
             SkASSERT(fCandidateVerts.originatingIdx(i) != -1);
             this->updatePt(fCandidateVerts.originatingIdx(i), fCandidateVerts.point(i), depth);
@@ -768,6 +787,84 @@ void GrAAConvexTessellator::checkAllDepths() const {
 }
 #endif
 
+#define kQuadTolerance 0.2f
+#define kCubicTolerance 0.2f
+#define kConicTolerance 0.5f
+
+void GrAAConvexTessellator::lineTo(const SkMatrix& m, SkPoint p, bool isCurve) {
+    m.mapPoints(&p, 1);
+    if (this->numPts() > 0 && duplicate_pt(p, this->lastPoint())) {
+        return;
+    }
+
+    SkASSERT(fPts.count() <= 1 || fPts.count() == fNorms.count()+1);
+    if (this->numPts() >= 2 && 
+        abs_dist_from_line(fPts.top(), fNorms.top(), p) < kClose) {
+        // The old last point is on the line from the second to last to the new point
+        this->popLastPt();
+        fNorms.pop();
+        fIsCurve.pop();
+    }
+    this->addPt(p, 0.0f, false, isCurve);
+    if (this->numPts() > 1) {
+        *fNorms.push() = fPts.top() - fPts[fPts.count()-2];
+        SkDEBUGCODE(SkScalar len =) SkPoint::Normalize(&fNorms.top());
+        SkASSERT(len > 0.0f);
+        SkASSERT(SkScalarNearlyEqual(1.0f, fNorms.top().length()));
+    }
+    SkDEBUGCODE(
+        if (this->numPts() >= 3) {
+            int cur = this->numPts()-1;
+            SkScalar cross = SkPoint::CrossProduct(fNorms[cur-1], fNorms[cur-2]);
+            fMaxCross = SkTMax(fMaxCross, cross);
+            fMinCross = SkTMin(fMinCross, cross);
+        }
+    )
+}
+
+void GrAAConvexTessellator::quadTo(const SkMatrix& m, SkPoint pts[3]) {
+    int maxCount = GrPathUtils::quadraticPointCount(pts, kQuadTolerance);
+    fPointBuffer.setReserve(maxCount);
+    SkPoint* target = fPointBuffer.begin();
+    int count = GrPathUtils::generateQuadraticPoints(pts[0], pts[1], pts[2], 
+            kQuadTolerance, &target, maxCount);
+    fPointBuffer.setCount(count);
+    for (int i = 0; i < count; i++) {
+        lineTo(m, fPointBuffer[i], true);
+    }
+}
+
+void GrAAConvexTessellator::cubicTo(const SkMatrix& m, SkPoint pts[4]) {
+    int maxCount = GrPathUtils::cubicPointCount(pts, kCubicTolerance);
+    fPointBuffer.setReserve(maxCount);
+    SkPoint* target = fPointBuffer.begin();
+    int count = GrPathUtils::generateCubicPoints(pts[0], pts[1], pts[2], pts[3], 
+            kCubicTolerance, &target, maxCount);
+    fPointBuffer.setCount(count);
+    for (int i = 0; i < count; i++) {
+        lineTo(m, fPointBuffer[i], true);
+    }
+}
+
+// include down here to avoid compilation errors caused by "-" overload in SkGeometry.h
+#include "SkGeometry.h"
+
+void GrAAConvexTessellator::conicTo(const SkMatrix& m, SkPoint* pts, SkScalar w) {
+    SkAutoConicToQuads quadder;
+    const SkPoint* quads = quadder.computeQuads(pts, w, kConicTolerance);
+    SkPoint lastPoint = *(quads++);
+    int count = quadder.countQuads();
+    for (int i = 0; i < count; ++i) {
+        SkPoint quadPts[3];
+        quadPts[0] = lastPoint;
+        quadPts[1] = quads[0];
+        quadPts[2] = i == count - 1 ? pts[2] : quads[1];
+        quadTo(m, quadPts);
+        lastPoint = quadPts[2];
+        quads += 2;
+    }
+}
+
 //////////////////////////////////////////////////////////////////////////////
 #if GR_AA_CONVEX_TESSELLATOR_VIZ
 static const SkScalar kPointRadius = 0.02f;

src/gpu/GrAAConvexTessellator.h

@@ -165,7 +165,7 @@ private:
     // Movable points are those that can be slid along their bisector.
     // Basically, a point is immovable if it is part of the original
     // polygon or it results from the fusing of two bisectors.
-    int addPt(const SkPoint& pt, SkScalar depth, bool movable);
+    int addPt(const SkPoint& pt, SkScalar depth, bool movable, bool isCurve);
     void popLastPt();
     void popFirstPtShuffle();
 
@@ -185,6 +185,14 @@ private:
                                 int edgeIdx, SkScalar desiredDepth,
                                 SkPoint* result) const;
 
+    void lineTo(const SkMatrix& m, SkPoint p, bool isCurve);
+
+    void quadTo(const SkMatrix& m, SkPoint pts[3]);
+
+    void cubicTo(const SkMatrix& m, SkPoint pts[4]);
+
+    void conicTo(const SkMatrix& m, SkPoint pts[3], SkScalar w);
+
     void terminate(const Ring& lastRing);
 
     // return false on failure/degenerate path
@@ -217,6 +225,11 @@ private:
     // The inward facing bisector at each point in the original polygon. Only
     // needed for exterior ring creation and then handed off to the initial ring.
     SkTDArray<SkVector> fBisectors;
+
+    // Tracks whether a given point is interior to a curve. Such points are 
+    // assumed to have shallow curvature.
+    SkTDArray<bool> fIsCurve;
+
     SkPoint::Side       fSide;    // winding of the original polygon
 
     // The triangulation of the points
@@ -233,10 +246,16 @@ private:
 
     SkScalar            fTargetDepth;
 
+    SkTDArray<SkPoint>  fPointBuffer;
+
     // If some goes wrong with the inset computation the tessellator will 
     // truncate the creation of the inset polygon. In this case the depth
     // check will complain.
     SkDEBUGCODE(bool fShouldCheckDepths;)
+
+    SkDEBUGCODE(SkScalar fMinCross;)
+    
+    SkDEBUGCODE(SkScalar fMaxCross;)
 };
 
 

src/gpu/GrAALinearizingConvexPathRenderer.cpp

@@ -0,0 +1,320 @@
+
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrAALinearizingConvexPathRenderer.h"
+
+#include "GrAAConvexTessellator.h"
+#include "GrBatch.h"
+#include "GrBatchTarget.h"
+#include "GrBatchTest.h"
+#include "GrContext.h"
+#include "GrDefaultGeoProcFactory.h"
+#include "GrGeometryProcessor.h"
+#include "GrInvariantOutput.h"
+#include "GrPathUtils.h"
+#include "GrProcessor.h"
+#include "GrPipelineBuilder.h"
+#include "GrStrokeInfo.h"
+#include "SkGeometry.h"
+#include "SkString.h"
+#include "SkTraceEvent.h"
+#include "gl/GrGLProcessor.h"
+#include "gl/GrGLSL.h"
+#include "gl/GrGLGeometryProcessor.h"
+#include "gl/builders/GrGLProgramBuilder.h"
+
+#define DEFAULT_BUFFER_SIZE 100
+
+GrAALinearizingConvexPathRenderer::GrAALinearizingConvexPathRenderer() {
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+bool GrAALinearizingConvexPathRenderer::canDrawPath(const GrDrawTarget* target,
+                                                    const GrPipelineBuilder*,
+                                                    const SkMatrix& viewMatrix,
+                                                    const SkPath& path,
+                                                    const GrStrokeInfo& stroke,
+                                                    bool antiAlias) const {
+    return (antiAlias && stroke.isFillStyle() && !path.isInverseFillType() && path.isConvex());
+}
+
+// extract the result vertices and indices from the GrAAConvexTessellator
+static void extract_verts(const GrAAConvexTessellator& tess,
+                          void* vertices,
+                          size_t vertexStride,
+                          GrColor color,
+                          uint16_t firstIndex,
+                          uint16_t* idxs,
+                          bool tweakAlphaForCoverage) {
+    intptr_t verts = reinterpret_cast<intptr_t>(vertices);
+
+    for (int i = 0; i < tess.numPts(); ++i) {
+        *((SkPoint*)((intptr_t)verts + i * vertexStride)) = tess.point(i);
+    }
+
+    // Make 'verts' point to the colors
+    verts += sizeof(SkPoint);
+    for (int i = 0; i < tess.numPts(); ++i) {
+        SkASSERT(tess.depth(i) >= -0.5f && tess.depth(i) <= 0.5f);
+        if (tweakAlphaForCoverage) {
+            SkASSERT(SkScalarRoundToInt(255.0f * (tess.depth(i) + 0.5f)) <= 255);
+            unsigned scale = SkScalarRoundToInt(255.0f * (tess.depth(i) + 0.5f));
+            GrColor scaledColor = (0xff == scale) ? color : SkAlphaMulQ(color, scale);
+            *reinterpret_cast<GrColor*>(verts + i * vertexStride) = scaledColor;
+        } else {
+            *reinterpret_cast<GrColor*>(verts + i * vertexStride) = color;
+            *reinterpret_cast<float*>(verts + i * vertexStride + sizeof(GrColor)) = 
+                                                                    tess.depth(i) + 0.5f;
+        }
+    }
+
+    for (int i = 0; i < tess.numIndices(); ++i) {
+        idxs[i] = tess.index(i) + firstIndex;
+    }
+}
+
+static const GrGeometryProcessor* create_fill_gp(bool tweakAlphaForCoverage,
+                                                 const SkMatrix& localMatrix,
+                                                 bool usesLocalCoords,
+                                                 bool coverageIgnored) {
+    uint32_t flags = GrDefaultGeoProcFactory::kColor_GPType;
+    if (!tweakAlphaForCoverage) {
+        flags |= GrDefaultGeoProcFactory::kCoverage_GPType;
+    }
+
+    return GrDefaultGeoProcFactory::Create(flags, GrColor_WHITE, usesLocalCoords, coverageIgnored,
+                                           SkMatrix::I(), localMatrix);
+}
+
+class AAFlatteningConvexPathBatch : public GrBatch {
+public:
+    struct Geometry {
+        GrColor fColor;
+        SkMatrix fViewMatrix;
+        SkPath fPath;
+    };
+
+    static GrBatch* Create(const Geometry& geometry) {
+        return SkNEW_ARGS(AAFlatteningConvexPathBatch, (geometry));
+    }
+
+    const char* name() const override { return "AAConvexBatch"; }
+
+    void getInvariantOutputColor(GrInitInvariantOutput* out) const override {
+        // When this is called on a batch, there is only one geometry bundle
+        out->setKnownFourComponents(fGeoData[0].fColor);
+    }
+    void getInvariantOutputCoverage(GrInitInvariantOutput* out) const override {
+        out->setUnknownSingleComponent();
+    }
+
+    void initBatchTracker(const GrPipelineInfo& init) override {
+        // Handle any color overrides
+        if (init.fColorIgnored) {
+            fGeoData[0].fColor = GrColor_ILLEGAL;
+        } else if (GrColor_ILLEGAL != init.fOverrideColor) {
+            fGeoData[0].fColor = init.fOverrideColor;
+        }
+
+        // setup batch properties
+        fBatch.fColorIgnored = init.fColorIgnored;
+        fBatch.fColor = fGeoData[0].fColor;
+        fBatch.fUsesLocalCoords = init.fUsesLocalCoords;
+        fBatch.fCoverageIgnored = init.fCoverageIgnored;
+        fBatch.fLinesOnly = SkPath::kLine_SegmentMask == fGeoData[0].fPath.getSegmentMasks();
+        fBatch.fCanTweakAlphaForCoverage = init.fCanTweakAlphaForCoverage;
+    }
+
+    void draw(GrBatchTarget* batchTarget, const GrPipeline* pipeline, int vertexCount, 
+            size_t vertexStride, void* vertices, int indexCount, uint16_t* indices) {
+        if (vertexCount == 0 || indexCount == 0) {
+            return;
+        }
+        const GrVertexBuffer* vertexBuffer;
+        GrVertices info;
+        int firstVertex;
+        void* verts = batchTarget->makeVertSpace(vertexStride, vertexCount, &vertexBuffer, 
+                &firstVertex);
+        if (!verts) {
+            SkDebugf("Could not allocate vertices\n");
+            return;
+        }
+        memcpy(verts, vertices, vertexCount * vertexStride);
+
+        const GrIndexBuffer* indexBuffer;
+        int firstIndex;
+        uint16_t* idxs = batchTarget->makeIndexSpace(indexCount, &indexBuffer, &firstIndex);
+        if (!idxs) {
+            SkDebugf("Could not allocate indices\n");
+            return;
+        }
+        memcpy(idxs, indices, indexCount * sizeof(uint16_t));
+        info.initIndexed(kTriangles_GrPrimitiveType, vertexBuffer, indexBuffer, firstVertex, 
+                firstIndex, vertexCount, indexCount);
+        batchTarget->draw(info);
+    }
+
+    void generateGeometry(GrBatchTarget* batchTarget, const GrPipeline* pipeline) override {
+        bool canTweakAlphaForCoverage = this->canTweakAlphaForCoverage();
+
+        SkMatrix invert;
+        if (this->usesLocalCoords() && !this->viewMatrix().invert(&invert)) {
+            SkDebugf("Could not invert viewmatrix\n");
+            return;
+        }
+
+        // Setup GrGeometryProcessor
+        SkAutoTUnref<const GrGeometryProcessor> gp(
+                                                create_fill_gp(canTweakAlphaForCoverage, invert,
+                                                               this->usesLocalCoords(),
+                                                               this->coverageIgnored()));
+
+        batchTarget->initDraw(gp, pipeline);
+
+        size_t vertexStride = gp->getVertexStride();
+
+        SkASSERT(canTweakAlphaForCoverage ?
+                 vertexStride == sizeof(GrDefaultGeoProcFactory::PositionColorAttr) :
+                 vertexStride == sizeof(GrDefaultGeoProcFactory::PositionColorCoverageAttr));
+
+        GrAAConvexTessellator tess;
+
+        int instanceCount = fGeoData.count();
+
+        int vertexCount = 0;
+        int indexCount = 0;
+        int maxVertices = DEFAULT_BUFFER_SIZE;
+        int maxIndices = DEFAULT_BUFFER_SIZE;
+        uint8_t* vertices = (uint8_t*) malloc(maxVertices * vertexStride);
+        uint16_t* indices = (uint16_t*) malloc(maxIndices * sizeof(uint16_t));
+        for (int i = 0; i < instanceCount; i++) {
+            tess.rewind();
+
+            Geometry& args = fGeoData[i];
+
+            if (!tess.tessellate(args.fViewMatrix, args.fPath)) {
+                continue;
+            }
+
+            int currentIndices = tess.numIndices();
+            SkASSERT(currentIndices <= UINT16_MAX);
+            if (indexCount + currentIndices > UINT16_MAX) {
+                // if we added the current instance, we would overflow the indices we can store in a 
+                // uint16_t. Draw what we've got so far and reset.
+                draw(batchTarget, pipeline, vertexCount, vertexStride, vertices, indexCount, 
+                        indices);
+                vertexCount = 0;
+                indexCount = 0;
+            }
+            int currentVertices = tess.numPts();
+            if (vertexCount + currentVertices > maxVertices) {
+                maxVertices = SkTMax(vertexCount + currentVertices, maxVertices * 2);
+                vertices = (uint8_t*) realloc(vertices, maxVertices * vertexStride);
+            }
+            if (indexCount + currentIndices > maxIndices) {
+                maxIndices = SkTMax(indexCount + currentIndices, maxIndices * 2);
+                indices = (uint16_t*) realloc(indices, maxIndices * sizeof(uint16_t));
+            }
+
+            extract_verts(tess, vertices + vertexStride * vertexCount, vertexStride, args.fColor, 
+                    vertexCount, indices + indexCount, canTweakAlphaForCoverage);
+            vertexCount += currentVertices;
+            indexCount += currentIndices;
+        }
+        draw(batchTarget, pipeline, vertexCount, vertexStride, vertices, indexCount, indices);
+        free(vertices);
+        free(indices);
+    }
+
+    SkSTArray<1, Geometry, true>* geoData() { return &fGeoData; }
+
+private:
+    AAFlatteningConvexPathBatch(const Geometry& geometry) {
+        this->initClassID<AAFlatteningConvexPathBatch>();
+        fGeoData.push_back(geometry);
+
+        // compute bounds
+        fBounds = geometry.fPath.getBounds();
+        geometry.fViewMatrix.mapRect(&fBounds);
+    }
+
+    bool onCombineIfPossible(GrBatch* t) override {
+        AAFlatteningConvexPathBatch* that = t->cast<AAFlatteningConvexPathBatch>();
+
+        SkASSERT(this->usesLocalCoords() == that->usesLocalCoords());
+        if (this->usesLocalCoords() && !this->viewMatrix().cheapEqualTo(that->viewMatrix())) {
+            return false;
+        }
+
+        // In the event of two batches, one who can tweak, one who cannot, we just fall back to
+        // not tweaking
+        if (this->canTweakAlphaForCoverage() != that->canTweakAlphaForCoverage()) {
+            fBatch.fCanTweakAlphaForCoverage = false;
+        }
+
+        fGeoData.push_back_n(that->geoData()->count(), that->geoData()->begin());
+        this->joinBounds(that->bounds());
+        return true;
+    }
+
+    GrColor color() const { return fBatch.fColor; }
+    bool linesOnly() const { return fBatch.fLinesOnly; }
+    bool usesLocalCoords() const { return fBatch.fUsesLocalCoords; }
+    bool canTweakAlphaForCoverage() const { return fBatch.fCanTweakAlphaForCoverage; }
+    const SkMatrix& viewMatrix() const { return fGeoData[0].fViewMatrix; }
+    bool coverageIgnored() const { return fBatch.fCoverageIgnored; }
+
+    struct BatchTracker {
+        GrColor fColor;
+        bool fUsesLocalCoords;
+        bool fColorIgnored;
+        bool fCoverageIgnored;
+        bool fLinesOnly;
+        bool fCanTweakAlphaForCoverage;
+    };
+
+    BatchTracker fBatch;
+    SkSTArray<1, Geometry, true> fGeoData;
+};
+
+bool GrAALinearizingConvexPathRenderer::onDrawPath(GrDrawTarget* target,
+                                                   GrPipelineBuilder* pipelineBuilder,
+                                                   GrColor color,
+                                                   const SkMatrix& vm,
+                                                   const SkPath& path,
+                                                   const GrStrokeInfo&,
+                                                   bool antiAlias) {
+    if (path.isEmpty()) {
+        return true;
+    }
+    AAFlatteningConvexPathBatch::Geometry geometry;
+    geometry.fColor = color;
+    geometry.fViewMatrix = vm;
+    geometry.fPath = path;
+
+    SkAutoTUnref<GrBatch> batch(AAFlatteningConvexPathBatch::Create(geometry));
+    target->drawBatch(pipelineBuilder, batch);
+
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+#ifdef GR_TEST_UTILS
+
+BATCH_TEST_DEFINE(AAFlatteningConvexPathBatch) {
+    AAFlatteningConvexPathBatch::Geometry geometry;
+    geometry.fColor = GrRandomColor(random);
+    geometry.fViewMatrix = GrTest::TestMatrixInvertible(random);
+    geometry.fPath = GrTest::TestPathConvex(random);
+
+    return AAFlatteningConvexPathBatch::Create(geometry);
+}
+
+#endif

src/gpu/GrAALinearizingConvexPathRenderer.h

@@ -0,0 +1,35 @@
+
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrAALinearizingConvexPathRenderer_DEFINED
+#define GrAALinearizingConvexPathRenderer_DEFINED
+
+#include "GrPathRenderer.h"
+
+class GrAALinearizingConvexPathRenderer : public GrPathRenderer {
+public:
+    GrAALinearizingConvexPathRenderer();
+
+    virtual bool canDrawPath(const GrDrawTarget*,
+                             const GrPipelineBuilder*,
+                             const SkMatrix& viewMatrix,
+                             const SkPath&,
+                             const GrStrokeInfo&,
+                             bool antiAlias) const override;
+
+protected:
+    virtual bool onDrawPath(GrDrawTarget*,
+                            GrPipelineBuilder*,
+                            GrColor,
+                            const SkMatrix& viewMatrix,
+                            const SkPath&,
+                            const GrStrokeInfo&,
+                            bool antiAlias) override;
+};
+
+#endif