// @(#)root/geom:$Id$
// Author: Mihaela Gheata   05/01/04

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#ifndef ROOT_TGeoPolygon
#define ROOT_TGeoPolygon

#include "TObject.h"

class TObjArray;

class TGeoPolygon : public TObject {
public:
   enum { kGeoConvex = BIT(9), kGeoFinishPolygon = BIT(10), kGeoACW = BIT(11) };

protected:
   // data members
   Int_t fNvert{0};                // number of vertices (must be defined clockwise in XY plane)
   Int_t fNconvex{0};              // number of points of the outscribed convex polygon
   Int_t *fInd{nullptr};           //[fNvert] list of vertex indices
   Int_t *fIndc{nullptr};          //[fNconvex] indices of vertices of the outscribed convex polygon
   Double_t *fX{nullptr};          //! pointer to list of current X coordinates of vertices
   Double_t *fY{nullptr};          //! pointer to list of current Y coordinates of vertices
   TObjArray *fDaughters{nullptr}; // list of concave daughters
private:
   void ConvexCheck(); // force convexity checking
   Bool_t IsSegConvex(Int_t i1, Int_t i2 = -1) const;
   Bool_t IsRightSided(const Double_t *point, Int_t ind1, Int_t ind2) const;
   void OutscribedConvex();

   TGeoPolygon(const TGeoPolygon &) = delete;
   TGeoPolygon &operator=(const TGeoPolygon &) = delete;

public:
   // constructors
   TGeoPolygon();
   TGeoPolygon(Int_t nvert);
   // destructor
   ~TGeoPolygon() override;
   // methods
   Double_t Area() const;
   Bool_t Contains(const Double_t *point) const;
   void Draw(Option_t *option = "") override;
   void FinishPolygon();
   Int_t GetNvert() const { return fNvert; }
   Int_t GetNconvex() const { return fNconvex; }
   Double_t *GetX() { return fX; }
   Double_t *GetY() { return fY; }
   void GetVertices(Double_t *x, Double_t *y) const;
   void GetConvexVertices(Double_t *x, Double_t *y) const;
   Bool_t IsClockwise() const { return !TObject::TestBit(kGeoACW); }
   Bool_t IsConvex() const { return TObject::TestBit(kGeoConvex); }
   Bool_t IsFinished() const { return TObject::TestBit(kGeoFinishPolygon); }
   Bool_t IsIllegalCheck() const;
   Double_t Safety(const Double_t *point, Int_t &isegment) const;
   void SetConvex(Bool_t flag = kTRUE) { TObject::SetBit(kGeoConvex, flag); }
   void SetXY(Double_t *x, Double_t *y);
   void SetNextIndex(Int_t index = -1);

   ClassDefOverride(TGeoPolygon, 2) // class for handling arbitrary polygons
};

#endif