combine vertical overlapping edges

src/core/SkEdgeBuilder.h

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkEdgeBuilder_DEFINED
 #define SkEdgeBuilder_DEFINED
 
 #include "SkChunkAlloc.h"
 #include "SkRect.h"
 #include "SkTDArray.h"
 
 struct SkEdge;
 class SkEdgeClipper;
 class SkPath;
 
 class SkEdgeBuilder {
 public:
     SkEdgeBuilder();
 
     // returns the number of built edges. The array of those edge pointers
     // is returned from edgeList().
     int build(const SkPath& path, const SkIRect* clip, int shiftUp, bool clipToTheRight);
 
     SkEdge** edgeList() { return fEdgeList; }
 
 private:
+    enum Combine {
+        kNo_Combine,
+        kPartial_Combine,
+        kTotal_Combine
+    };
+
+    static Combine CombineVertical(const SkEdge* edge, SkEdge* last);
+    Combine checkVertical(const SkEdge* edge, SkEdge** edgePtr);
+
     SkChunkAlloc        fAlloc;
     SkTDArray<SkEdge*>  fList;
 
     /*
      *  If we're in general mode, we allcoate the pointers in fList, and this
      *  will point at fList.begin(). If we're in polygon mode, fList will be
      *  empty, as we will have preallocated room for the pointers in fAlloc's
      *  block, and fEdgeList will point into that.
      */
     SkEdge**    fEdgeList;
 
     int         fShiftUp;
 
 public:
     void addLine(const SkPoint pts[]);
     void addQuad(const SkPoint pts[]);
     void addCubic(const SkPoint pts[]);
     void addClipper(SkEdgeClipper*);
 
     int buildPoly(const SkPath& path, const SkIRect* clip, int shiftUp, bool clipToTheRight);
 };
 
 #endif