Clipper.h

/*******************************************************************************
*                                                                              *
* 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 ClipperH
#define ClipperH

#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
  {
    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;
  };
}  //namespace ClipperLib


#endif