added stroking support to GrAALinearizingConvexPathRenderer

src/gpu/GrAAConvexTessellator.h

 /*
  * 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 GrAAConvexTessellator_DEFINED
 #define GrAAConvexTessellator_DEFINED
 
 #include "SkColor.h"
+#include "SkPaint.h"
 #include "SkPoint.h"
 #include "SkScalar.h"
 #include "SkTDArray.h"
 
 class SkCanvas;
 class SkMatrix;
 class SkPath;
 
 //#define GR_AA_CONVEX_TESSELLATOR_VIZ 1
 
+// device space distance which we inset / outset points in order to create the soft antialiased edge
+static const SkScalar kAntialiasingRadius = 0.5f;
+
 class GrAAConvexTessellator;
 
 // The AAConvexTessellator holds the global pool of points and the triangulation
 // that connects them. It also drives the tessellation process.
 // The outward facing normals of the original polygon are stored (in 'fNorms') to service
 // computeDepthFromEdge requests.
 class GrAAConvexTessellator {
 public:
-    GrAAConvexTessellator(SkScalar targetDepth = 0.5f)
+    GrAAConvexTessellator(SkScalar strokeWidth = -1.0f, 
+                          SkPaint::Join join = SkPaint::Join::kBevel_Join, 
+                          SkScalar miterLimit = 0.0f)
         : fSide(SkPoint::kOn_Side)
-        , fTargetDepth(targetDepth) {
+        , fStrokeWidth(strokeWidth)
+        , fJoin(join)
+        , fMiterLimit(miterLimit) {
     }
 
-    void setTargetDepth(SkScalar targetDepth) { fTargetDepth = targetDepth; }
-    SkScalar targetDepth() const { return fTargetDepth; }
-
     SkPoint::Side side() const { return fSide; }
 
     bool tessellate(const SkMatrix& m, const SkPath& path);
 
     // The next five should only be called after tessellate to extract the result
     int numPts() const { return fPts.count(); }
     int numIndices() const { return fIndices.count(); }
 
     const SkPoint& lastPoint() const { return fPts.top(); }
     const SkPoint& point(int index) const { return fPts[index]; }
     int index(int index) const { return fIndices[index]; }
-    SkScalar depth(int index) const {return fDepths[index]; }
+    SkScalar coverage(int index) const { return fCoverages[index]; }
 
 #if GR_AA_CONVEX_TESSELLATOR_VIZ
     void draw(SkCanvas* canvas) const;
 #endif
 
     // The tessellator can be reused for multiple paths by rewinding in between
     void rewind();
 
 private:
     // CandidateVerts holds the vertices for the next ring while they are 
@@ skipping 72 matching lines @@
         }
 
         // init should be called after all the indices have been added (via addIdx)
         void init(const GrAAConvexTessellator& tess);
         void init(const SkTDArray<SkVector>& norms, const SkTDArray<SkVector>& bisectors);
 
         const SkPoint& norm(int index) const { return fPts[index].fNorm; }
         const SkPoint& bisector(int index) const { return fPts[index].fBisector; }
         int index(int index) const { return fPts[index].fIndex; }
         int origEdgeID(int index) const { return fPts[index].fOrigEdgeId; }
+        void setOrigEdgeId(int index, int id) { fPts[index].fOrigEdgeId = id; }
 
     #if GR_AA_CONVEX_TESSELLATOR_VIZ
         void draw(SkCanvas* canvas, const GrAAConvexTessellator& tess) const;
     #endif
 
     private:
         void computeNormals(const GrAAConvexTessellator& result);
         void computeBisectors(const GrAAConvexTessellator& tess);
 
         SkDEBUGCODE(bool isConvex(const GrAAConvexTessellator& tess) const;)
 
         struct PointData {
             SkPoint fNorm;
             SkPoint fBisector;
             int     fIndex;
             int     fOrigEdgeId;
         };
 
         SkTDArray<PointData> fPts;
     };
 
     bool movable(int index) const { return fMovable[index]; }
 
     // 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, bool isCurve);
+    int addPt(const SkPoint& pt, SkScalar depth, SkScalar coverage, bool movable, bool isCurve);
     void popLastPt();
     void popFirstPtShuffle();
 
-    void updatePt(int index, const SkPoint& pt, SkScalar depth);
+    void updatePt(int index, const SkPoint& pt, SkScalar depth, SkScalar coverage);
 
     void addTri(int i0, int i1, int i2);
 
     void reservePts(int count) {
         fPts.setReserve(count);
-        fDepths.setReserve(count);  
+        fCoverages.setReserve(count);
         fMovable.setReserve(count);
     }
 
     SkScalar computeDepthFromEdge(int edgeIdx, const SkPoint& p) const;
 
     bool computePtAlongBisector(int startIdx, const SkPoint& bisector,
                                 int edgeIdx, SkScalar desiredDepth,
                                 SkPoint* result) const;
 
+    void lineTo(SkPoint p, bool isCurve);
+
     void lineTo(const SkMatrix& m, SkPoint p, bool isCurve);
 
+    void quadTo(SkPoint pts[3]);
+
     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
     bool extractFromPath(const SkMatrix& m, const SkPath& path);
     void computeBisectors();
 
     void fanRing(const Ring& ring);
-    void createOuterRing();
 
     Ring* getNextRing(Ring* lastRing);
 
-    bool createInsetRing(const Ring& lastRing, Ring* nextRing);
+    void createOuterRing(const Ring& previousRing, SkScalar outset, SkScalar coverage, 
+                         Ring* nextRing);
+
+    bool createInsetRings(Ring& previousRing, SkScalar initialDepth, SkScalar initialCoverage, 
+                          SkScalar targetDepth, SkScalar targetCoverage, Ring** finalRing);
+
+    bool createInsetRing(const Ring& lastRing, Ring* nextRing, 
+                         SkScalar initialDepth, SkScalar initialCoverage, SkScalar targetDepth, 
+                         SkScalar targetCoverage, bool forceNew);
 
     void validate() const;
 
-
-#ifdef SK_DEBUG
-    SkScalar computeRealDepth(const SkPoint& p) const;
-    void checkAllDepths() const;
-#endif
-
-    // fPts, fWeights & fMovable should always have the same # of elements
+    // fPts, fCoverages & fMovable should always have the same # of elements
     SkTDArray<SkPoint>  fPts;
-    SkTDArray<SkScalar> fDepths;
+    SkTDArray<SkScalar> fCoverages;
     // movable points are those that can be slid further along their bisector
     SkTDArray<bool>     fMovable;
 
     // The outward facing normals for the original polygon
     SkTDArray<SkVector> fNorms;
     // 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
     SkTDArray<int>      fIndices;
 
     Ring                fInitialRing;
 #if GR_AA_CONVEX_TESSELLATOR_VIZ
     // When visualizing save all the rings
     SkTDArray<Ring*>    fRings;
 #else
     Ring                fRings[2];
 #endif
     CandidateVerts      fCandidateVerts;
 
-    SkScalar            fTargetDepth;
+    // < 0 means filling rather than stroking
+    SkScalar            fStrokeWidth;
+
+    SkPaint::Join        fJoin;
+
+    SkScalar            fMiterLimit;
 
     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;)
 };
 
 
 #endif