text: /*******************************************************************************
  *                                                                              *
  * Author    :  Angus Johnson                                                   *
  * Version   :  6.4.2                                                           *
  * Date      :  27 February 2017                                                *
  * Website   :  http://www.angusj.com                                           *
  * Copyright :  Angus Johnson 2010-2017                                         *
  *                                                                              *
  * License:                                                                     *
  * Use, modification & distribution is subject to Boost Software License Ver 1. *
  * http://www.boost.org/LICENSE_1_0.txt                                         *
  *                                                                              *
  * Attributions:                                                                *
  * The code in this library is an extension of Bala Vatti's clipping algorithm: *
  * "A generic solution to polygon clipping"                                     *
  * Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63.             *
  * http://portal.acm.org/citation.cfm?id=129906                                 *
  *                                                                              *
  * Computer graphics and geometric modeling: implementation and algorithms      *
  * By Max K. Agoston                                                            *
  * Springer; 1 edition (January 4, 2005)                                        *
  * http://books.google.com/books?q=vatti+clipping+agoston                       *
  *                                                                              *
  * See also:                                                                    *
  * "Polygon Offsetting by Computing Winding Numbers"                            *
  * Paper no. DETC2005-85513 pp. 565-575                                         *
  * ASME 2005 International Design Engineering Technical Conferences             *
  * and Computers and Information in Engineering Conference (IDETC/CIE2005)      *
  * September 24-28, 2005 , Long Beach, California, USA                          *
  * http://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf              *
  *                                                                              *
  *******************************************************************************/
  
  #ifndef clipper_hpp
  #define clipper_hpp
  
  #define CLIPPER_VERSION "6.4.2"
  
  //use_int32: When enabled 32bit ints are used instead of 64bit ints. This
  //improve performance but coordinate values are limited to the range +/- 46340
  //#define use_int32
  
  //use_xyz: adds a Z member to IntPoint. Adds a minor cost to perfomance.
  //#define use_xyz
  
  //use_lines: Enables line clipping. Adds a very minor cost to performance.
  #define use_lines
    
  //use_deprecated: Enables temporary support for the obsolete functions
  //#define use_deprecated  
  
  #include <vector>
  #include <list>
  #include <set>
  #include <stdexcept>
  #include <cstring>
  #include <cstdlib>
  #include <ostream>
  #include <functional>
  #include <queue>
  
  namespace ClipperLib {
  
  enum ClipType { ctIntersection, ctUnion, ctDifference, ctXor };
  enum PolyType { ptSubject, ptClip };
  //By far the most widely used winding rules for polygon filling are
  //EvenOdd & NonZero (GDI, GDI+, XLib, OpenGL, Cairo, AGG, Quartz, SVG, Gr32)
  //Others rules include Positive, Negative and ABS_GTR_EQ_TWO (only in OpenGL)
  //see http://glprogramming.com/red/chapter11.html
  enum PolyFillType { pftEvenOdd, pftNonZero, pftPositive, pftNegative };
  
  #ifdef use_int32
    typedef int cInt;
    static cInt const loRange = 0x7FFF;
    static cInt const hiRange = 0x7FFF;
  #else
    typedef signed long long cInt;
    static cInt const loRange = 0x3FFFFFFF;
    static cInt const hiRange = 0x3FFFFFFFFFFFFFFFLL;
    typedef signed long long long64;     //used by Int128 class
    typedef unsigned long long ulong64;
  
  #endif
  
  struct IntPoint {
  public:
    cInt X;
    cInt Y;
  #ifdef use_xyz
    cInt Z;
    IntPoint(cInt x = 0, cInt y = 0, cInt z = 0): X(x), Y(y), Z(z) {};
  #else
    IntPoint(cInt x = 0, cInt y = 0): X(x), Y(y) {};
  #endif
  
    friend inline bool operator== (const IntPoint& a, const IntPoint& b)
    {
      return a.X == b.X && a.Y == b.Y;
    }
    friend inline bool operator!= (const IntPoint& a, const IntPoint& b)
    {
      return a.X != b.X  || a.Y != b.Y; 
    }
  };
  //------------------------------------------------------------------------------
  
  typedef std::vector< IntPoint > Path;
  typedef std::vector< Path > Paths;
  
  inline Path& operator <<(Path& poly, const IntPoint& p) {poly.push_back(p); return poly;}
  inline Paths& operator <<(Paths& polys, const Path& p) {polys.push_back(p); return polys;}
  
  std::ostream& operator <<(std::ostream &s, const IntPoint &p);
  std::ostream& operator <<(std::ostream &s, const Path &p);
  std::ostream& operator <<(std::ostream &s, const Paths &p);
  
  struct DoublePoint
  {
    double X;
    double Y;
    DoublePoint(double x = 0, double y = 0) : X(x), Y(y) {}
    DoublePoint(IntPoint ip) : X((double)ip.X), Y((double)ip.Y) {}
  };
  //------------------------------------------------------------------------------
  
  #ifdef use_xyz
  typedef void (*ZFillCallback)(IntPoint& e1bot, IntPoint& e1top, IntPoint& e2bot, IntPoint& e2top, IntPoint& pt);
  #endif
  
  enum InitOptions {ioReverseSolution = 1, ioStrictlySimple = 2, ioPreserveCollinear = 4};
  enum JoinType {jtSquare, jtRound, jtMiter};
  enum EndType {etClosedPolygon, etClosedLine, etOpenButt, etOpenSquare, etOpenRound};
  
  class PolyNode;
  typedef std::vector< PolyNode* > PolyNodes;
  
  class PolyNode 
  { 
  public:
      PolyNode();
      virtual ~PolyNode(){};
      Path Contour;
      PolyNodes Childs;
      PolyNode* Parent;
      PolyNode* GetNext() const;
      bool IsHole() const;
      bool IsOpen() const;
      int ChildCount() const;
  private:
      //PolyNode& operator =(PolyNode& other); 
      unsigned Index; //node index in Parent.Childs
      bool m_IsOpen;
      JoinType m_jointype;
      EndType m_endtype;
      PolyNode* GetNextSiblingUp() const;
      void AddChild(PolyNode& child);
      friend class Clipper; //to access Index
      friend class ClipperOffset; 
  };
  
  class PolyTree: public PolyNode
  { 
  public:
      ~PolyTree(){ Clear(); };
      PolyNode* GetFirst() const;
      void Clear();
      int Total() const;
  private:
    //PolyTree& operator =(PolyTree& other);
    PolyNodes AllNodes;
      friend class Clipper; //to access AllNodes
  };
  
  bool Orientation(const Path &poly);
  double Area(const Path &poly);
  int PointInPolygon(const IntPoint &pt, const Path &path);
  
  void SimplifyPolygon(const Path &in_poly, Paths &out_polys, PolyFillType fillType = pftEvenOdd);
  void SimplifyPolygons(const Paths &in_polys, Paths &out_polys, PolyFillType fillType = pftEvenOdd);
  void SimplifyPolygons(Paths &polys, PolyFillType fillType = pftEvenOdd);
  
  void CleanPolygon(const Path& in_poly, Path& out_poly, double distance = 1.415);
  void CleanPolygon(Path& poly, double distance = 1.415);
  void CleanPolygons(const Paths& in_polys, Paths& out_polys, double distance = 1.415);
  void CleanPolygons(Paths& polys, double distance = 1.415);
  
  void MinkowskiSum(const Path& pattern, const Path& path, Paths& solution, bool pathIsClosed);
  void MinkowskiSum(const Path& pattern, const Paths& paths, Paths& solution, bool pathIsClosed);
  void MinkowskiDiff(const Path& poly1, const Path& poly2, Paths& solution);
  
  void PolyTreeToPaths(const PolyTree& polytree, Paths& paths);
  void ClosedPathsFromPolyTree(const PolyTree& polytree, Paths& paths);
  void OpenPathsFromPolyTree(PolyTree& polytree, Paths& paths);
  
  void ReversePath(Path& p);
  void ReversePaths(Paths& p);
  
  struct IntRect { cInt left; cInt top; cInt right; cInt bottom; };
  
  //enums that are used internally ...
  enum EdgeSide { esLeft = 1, esRight = 2};
  
  //forward declarations (for stuff used internally) ...
  struct TEdge;
  struct IntersectNode;
  struct LocalMinimum;
  struct OutPt;
  struct OutRec;
  struct Join;
  
  typedef std::vector < OutRec* > PolyOutList;
  typedef std::vector < TEdge* > EdgeList;
  typedef std::vector < Join* > JoinList;
  typedef std::vector < IntersectNode* > IntersectList;
  
  //------------------------------------------------------------------------------
  
  //ClipperBase is the ancestor to the Clipper class. It should not be
  //instantiated directly. This class simply abstracts the conversion of sets of
  //polygon coordinates into edge objects that are stored in a LocalMinima list.
  class ClipperBase
  {
  public:
    ClipperBase();
    virtual ~ClipperBase();
    virtual bool AddPath(const Path &pg, PolyType PolyTyp, bool Closed);
    bool AddPaths(const Paths &ppg, PolyType PolyTyp, bool Closed);
    virtual void Clear();
    IntRect GetBounds();
    bool PreserveCollinear() {return m_PreserveCollinear;};
    void PreserveCollinear(bool value) {m_PreserveCollinear = value;};
  protected:
    void DisposeLocalMinimaList();
    TEdge* AddBoundsToLML(TEdge *e, bool IsClosed);
    virtual void Reset();
    TEdge* ProcessBound(TEdge* E, bool IsClockwise);
    void InsertScanbeam(const cInt Y);
    bool PopScanbeam(cInt &Y);
    bool LocalMinimaPending();
    bool PopLocalMinima(cInt Y, const LocalMinimum *&locMin);
    OutRec* CreateOutRec();
    void DisposeAllOutRecs();
    void DisposeOutRec(PolyOutList::size_type index);
    void SwapPositionsInAEL(TEdge *edge1, TEdge *edge2);
    void DeleteFromAEL(TEdge *e);
    void UpdateEdgeIntoAEL(TEdge *&e);
  
    typedef std::vector<LocalMinimum> MinimaList;
    MinimaList::iterator m_CurrentLM;
    MinimaList           m_MinimaList;
  
    bool              m_UseFullRange;
    EdgeList          m_edges;
    bool              m_PreserveCollinear;
    bool              m_HasOpenPaths;
    PolyOutList       m_PolyOuts;
    TEdge           *m_ActiveEdges;
  
    typedef std::priority_queue<cInt> ScanbeamList;
    ScanbeamList     m_Scanbeam;
  };
  //------------------------------------------------------------------------------
  
  class Clipper : public virtual ClipperBase
  {
  public:
    Clipper(int initOptions = 0);
    bool Execute(ClipType clipType,
        Paths &solution,
        PolyFillType fillType = pftEvenOdd);
    bool Execute(ClipType clipType,
        Paths &solution,
        PolyFillType subjFillType,
        PolyFillType clipFillType);
    bool Execute(ClipType clipType,
        PolyTree &polytree,
        PolyFillType fillType = pftEvenOdd);
    bool Execute(ClipType clipType,
        PolyTree &polytree,
        PolyFillType subjFillType,
        PolyFillType clipFillType);
    bool ReverseSolution() { return m_ReverseOutput; };
    void ReverseSolution(bool value) {m_ReverseOutput = value;};
    bool StrictlySimple() {return m_StrictSimple;};
    void StrictlySimple(bool value) {m_StrictSimple = value;};
    //set the callback function for z value filling on intersections (otherwise Z is 0)
  #ifdef use_xyz
    void ZFillFunction(ZFillCallback zFillFunc);
  #endif
  protected:
    virtual bool ExecuteInternal();
  private:
    JoinList         m_Joins;
    JoinList         m_GhostJoins;
    IntersectList    m_IntersectList;
    ClipType         m_ClipType;
    typedef std::list<cInt> MaximaList;
    MaximaList       m_Maxima;
    TEdge           *m_SortedEdges;
    bool             m_ExecuteLocked;
    PolyFillType     m_ClipFillType;
    PolyFillType     m_SubjFillType;
    bool             m_ReverseOutput;
    bool             m_UsingPolyTree; 
    bool             m_StrictSimple;
  #ifdef use_xyz
    ZFillCallback   m_ZFill; //custom callback 
  #endif
    void SetWindingCount(TEdge& edge);
    bool IsEvenOddFillType(const TEdge& edge) const;
    bool IsEvenOddAltFillType(const TEdge& edge) const;
    void InsertLocalMinimaIntoAEL(const cInt botY);
    void InsertEdgeIntoAEL(TEdge *edge, TEdge* startEdge);
    void AddEdgeToSEL(TEdge *edge);
    bool PopEdgeFromSEL(TEdge *&edge);
    void CopyAELToSEL();
    void DeleteFromSEL(TEdge *e);
    void SwapPositionsInSEL(TEdge *edge1, TEdge *edge2);
    bool IsContributing(const TEdge& edge) const;
    bool IsTopHorz(const cInt XPos);
    void DoMaxima(TEdge *e);
    void ProcessHorizontals();
    void ProcessHorizontal(TEdge *horzEdge);
    void AddLocalMaxPoly(TEdge *e1, TEdge *e2, const IntPoint &pt);
    OutPt* AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &pt);
    OutRec* GetOutRec(int idx);
    void AppendPolygon(TEdge *e1, TEdge *e2);
    void IntersectEdges(TEdge *e1, TEdge *e2, IntPoint &pt);
    OutPt* AddOutPt(TEdge *e, const IntPoint &pt);
    OutPt* GetLastOutPt(TEdge *e);
    bool ProcessIntersections(const cInt topY);
    void BuildIntersectList(const cInt topY);
    void ProcessIntersectList();
    void ProcessEdgesAtTopOfScanbeam(const cInt topY);
    void BuildResult(Paths& polys);
    void BuildResult2(PolyTree& polytree);
    void SetHoleState(TEdge *e, OutRec *outrec);
    void DisposeIntersectNodes();
    bool FixupIntersectionOrder();
    void FixupOutPolygon(OutRec &outrec);
    void FixupOutPolyline(OutRec &outrec);
    bool IsHole(TEdge *e);
    bool FindOwnerFromSplitRecs(OutRec &outRec, OutRec *&currOrfl);
    void FixHoleLinkage(OutRec &outrec);
    void AddJoin(OutPt *op1, OutPt *op2, const IntPoint offPt);
    void ClearJoins();
    void ClearGhostJoins();
    void AddGhostJoin(OutPt *op, const IntPoint offPt);
    bool JoinPoints(Join *j, OutRec* outRec1, OutRec* outRec2);
    void JoinCommonEdges();
    void DoSimplePolygons();
    void FixupFirstLefts1(OutRec* OldOutRec, OutRec* NewOutRec);
    void FixupFirstLefts2(OutRec* InnerOutRec, OutRec* OuterOutRec);
    void FixupFirstLefts3(OutRec* OldOutRec, OutRec* NewOutRec);
  #ifdef use_xyz
    void SetZ(IntPoint& pt, TEdge& e1, TEdge& e2);
  #endif
  };
  //------------------------------------------------------------------------------
  
  class ClipperOffset 
  {
  public:
    ClipperOffset(double miterLimit = 2.0, double roundPrecision = 0.25);
    ~ClipperOffset();
    void AddPath(const Path& path, JoinType joinType, EndType endType);
    void AddPaths(const Paths& paths, JoinType joinType, EndType endType);
    void Execute(Paths& solution, double delta);
    void Execute(PolyTree& solution, double delta);
    void Clear();
    double MiterLimit;
    double ArcTolerance;
  private:
    Paths m_destPolys;
    Path m_srcPoly;
    Path m_destPoly;
    std::vector<DoublePoint> m_normals;
    double m_delta, m_sinA, m_sin, m_cos;
    double m_miterLim, m_StepsPerRad;
    IntPoint m_lowest;
    PolyNode m_polyNodes;
  
    void FixOrientations();
    void DoOffset(double delta);
    void OffsetPoint(int j, int& k, JoinType jointype);
    void DoSquare(int j, int k);
    void DoMiter(int j, int k, double r);
    void DoRound(int j, int k);
  };
  //------------------------------------------------------------------------------
  
  class clipperException : public std::exception
  {
    public:
      clipperException(const char* description): m_descr(description) {}
      virtual ~clipperException() throw() {}
      virtual const char* what() const throw() {return m_descr.c_str();}
    private:
      std::string m_descr;
  };
  //------------------------------------------------------------------------------
  
  } //ClipperLib namespace
  
  #endif //clipper_hpp
  
  
  