/****************************************************************************
* VCGLib                                                            o o     *
* Visual and Computer Graphics Library                            o     o   *
*                                                                _   O  _   *
* Copyright(C) 2004-2016                                           \/)\/    *
* Visual Computing Lab                                            /\/|      *
* ISTI - Italian National Research Council                           |      *
*                                                                    \      *
* All rights reserved.                                                      *
*                                                                           *
* This program is free software; you can redistribute it and/or modify      *
* it under the terms of the GNU General Public License as published by      *
* the Free Software Foundation; either version 2 of the License, or         *
* (at your option) any later version.                                       *
*                                                                           *
* This program is distributed in the hope that it will be useful,           *
* but WITHOUT ANY WARRANTY; without even the implied warranty of            *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             *
* GNU General Public License (http://www.gnu.org/licenses/gpl.txt)          *
* for more details.                                                         *
*                                                                           *
****************************************************************************/
#ifndef __VCG_TRI_UPDATE_HOLE
#define __VCG_TRI_UPDATE_HOLE

#include <vcg/complex/algorithms/clean.h>

// This file contains three Ear Classes
// - TrivialEar
// - MinimumWeightEar
// - SelfIntersectionEar
// and a static class Hole for filling holes that is templated on the ear class



namespace vcg {
    namespace tri {

    
    /*
    An ear is identified by TWO pos.
    The Three vertexes of an Ear are:
    e0.VFlip().v
    e0.v
    e1.v
    Invariants:
      e1 == e0.NextB();
      e1.FlipV() == e0;

    */
/**
 * Basic class for representing an 'ear' in a hole. 
 * 
 * Require FF-adajcncy and edge-manifoldness around the mesh (at most two triangles per edge)
 * 
 * An ear is represented by two consecutive Pos e0,e1.
 * The vertex pointed by the first pos is the 'corner' of the ear
 * 
 *
 */
template<class MESH> class TrivialEar
{
public:
  typedef typename MESH::FaceType      FaceType;
  typedef typename MESH::VertexType    VertexType;
  typedef typename MESH::FacePointer   FacePointer;
  typedef typename MESH::VertexPointer VertexPointer;
  typedef typename face::Pos<FaceType> PosType;
  typedef typename MESH::ScalarType    ScalarType;
  typedef typename MESH::CoordType     CoordType;
  
  PosType e0;
  PosType e1;
  CoordType n; // the normal of the face defined by the ear
  
  const char * Dump() {return 0;}
  // The following members are useful to consider the Ear as a generic <triangle>
  // with p0 the 'center' of the ear.
  const CoordType &cP(int i) const {return P(i);}
  const CoordType &P(int i) const {
    switch(i) {
    case 0 : return e0.v->P();
    case 1 : return e1.v->P();
    case 2 : return e0.VFlip()->P();
    default: assert(0);
    }
    return e0.v->P();
  }

  ScalarType quality;
  ScalarType angleRad;
  TrivialEar(){}
  TrivialEar(const PosType & ep)
  {
    e0=ep;
    assert(e0.IsBorder());
    e1=e0;
    e1.NextB();
    n=TriangleNormal<TrivialEar>(*this);
    ComputeQuality();
    ComputeAngle();
  }
  // enforce virtual dtor for this class and all subclasses
  virtual ~TrivialEar() = default;

  /// Compute the angle of the two edges of the ear.
  // it tries to make the computation in a precision safe way.
  // the angle computation takes into account the case of reversed ears
  void ComputeAngle()
  {
    angleRad=Angle(cP(2)-cP(0), cP(1)-cP(0));
    ScalarType flipAngle = n.dot(e0.v->N());
    if(flipAngle<0)		angleRad = (2.0 *(ScalarType)M_PI) - angleRad;
  }

  virtual inline bool operator < ( const TrivialEar & c ) const { return quality <  c.quality; }

  bool IsNull(){return e0.IsNull() || e1.IsNull();}
  void SetNull(){e0.SetNull();e1.SetNull();}
  virtual	void ComputeQuality() {	quality = QualityFace(*this) ; }
  bool IsUpToDate()	{return ( e0.IsBorder() && e1.IsBorder());}
  // An ear is degenerated if both of its two endpoints are non manifold.
  bool IsDegen()
  {
    if(e0.VFlip()->IsUserBit(NonManifoldBit()) && e1.V()->IsUserBit(NonManifoldBit()))
      return true;
    else return false;
  }
  bool IsConcave() const {return(angleRad > (float)M_PI);}

  
  /** NonManifoldBit
   * To handle non manifoldness situations we keep track 
   * of the vertices of the hole boundary that are traversed by more than a single boundary.
   * 
   */
  static int &NonManifoldBit() { static int _NonManifoldBit=0; return _NonManifoldBit; }
  static int InitNonManifoldBitOnHoleBoundary(const PosType &p)       
  {
    if(NonManifoldBit()==0) 
      NonManifoldBit() = VertexType::NewBitFlag(); 
    int holeSize=0;
    
    //First loop around the hole to mark non manifold vertices.
    PosType ip = p;   // Pos iterator
    do{
      ip.V()->ClearUserBit(NonManifoldBit());
      ip.V()->ClearV();
      ip.NextB();
      holeSize++;
    } while(ip!=p);
    
    ip = p;   // Re init the pos iterator for another loop (useless if everithing is ok!!)
    do{
      if(!ip.V()->IsV())
        ip.V()->SetV();  
      else  // All the vertexes that are visited more than once are non manifold
        ip.V()->SetUserBit(NonManifoldBit());
      ip.NextB();
    } while(ip!=p);
    return holeSize;
  }
  
  
  
  
  // When you close an ear you have to check that the newly added triangle does not create non manifold situations
  // This can happen if the new edge already exists in the mesh.
  // We test that looping around one extreme of the ear we do not find the other vertex
  bool CheckManifoldAfterEarClose()
  {
    PosType pp = e1;
    VertexPointer otherV =  e0.VFlip();
    assert(pp.IsBorder());
    do
    {
      pp.FlipE();
      pp.FlipF();
      if(pp.VFlip()==otherV) return false;
    }
    while(!pp.IsBorder());
    return true;
  }
  /**
   * @brief Close the current ear by adding a triangle to the mesh
   * and returning up to two new possible ears to be closed. 
   * 
   * @param np0 The first new pos to be inserted in the heap
   * @param np1 The second new pos
   * @param f the already allocated face to be used to close the ear
   * @return true if it successfully add a triangle 
   * 
   *  +\                      
   *  +++\             ------- 
   *  +++ep\         /| +++en/\
   *  +++---|      /e1 ++++++++\
   *  ++++++|    /++++++++++++++\
   *  +++ e0|o /+++++++++++++++++++
   *  +++  \|/+++++++++++++++++++++
   *  +++++++++++++++++++++++++++++
   * 
   *    There are three main peculiar cases:
   
   *   (T)+++++++++++++    (A)       /+++++       (B)       /en+++++++
   *   /+++++++++++++++             /++++++                /++++++++++
   *   ++++++ep==en +++      ep\   /en ++++               /e1 ++++++++
   *   ++++++ ----/| ++    ------ ----/| ++       ------------/|+++
   *   ++++++|   /e1 ++    ++++++|   /e1 ++       ++++++|   o/e0|+++
   *   ++++++|  /++++++    ++++++|  /++++++       ++++++|  /++++++++
   *   +++ e0|o/+++++++    +++ e0|o/+++++++       +++ ep| /++++++++++
   *   +++  \|/++++++++    +++  \|/++++++++       +++  \|/++++++++++++
   *   ++++++++++++++++    ++++++++++++++++       ++++++++++++++++++++
   */
  
  virtual bool Close(PosType &np0, PosType &np1, FaceType *f)
  {
    // simple topological check
    if(e0.f==e1.f) {
      //printf("Avoided bad ear");
      return false;
    }

    PosType	ep=e0; ep.FlipV(); ep.NextB(); ep.FlipV(); // ep previous
    PosType	en=e1; en.NextB();												 // en next
    if(ep!=en)
      if(!CheckManifoldAfterEarClose()) return false;

    (*f).V(0) = e0.VFlip();
    (*f).V(1) = e0.v;
    (*f).V(2) = e1.v;
    f->N() = TriangleNormal(*f).Normalize();

    face::FFAttachManifold(f,0,e0.f,e0.z);
    face::FFAttachManifold(f,1,e1.f,e1.z);
    face::FFSetBorder(f,2);

    // First Special Case (T): Triangular hole
    if(ep==en)
    {
      //printf("Closing the last triangle");
      face::FFAttachManifold(f,2,en.f,en.z);
      np0.SetNull();
      np1.SetNull();
    }
    // Second Special Case (A): Non Manifold on ep 
    else if(ep.v==en.v)
    {
      //printf("Ear Non manif A\n");
      assert(ep.v->IsUserBit(NonManifoldBit()));
      ep.v->ClearUserBit(NonManifoldBit());
      PosType	enold=en;
      en.NextB();
      face::FFAttachManifold(f,2,enold.f,enold.z);
      np0=ep;
      assert(!np0.v->IsUserBit(NonManifoldBit()));      
      np1.SetNull();
    }
    // Third Special Case (B): Non Manifold on e1
    else if(ep.VFlip()==e1.v)
    {
      assert(e1.v->IsUserBit(NonManifoldBit()));
      e1.v->ClearUserBit(NonManifoldBit());
      //printf("Ear Non manif B\n");
      PosType	epold=ep;
      ep.FlipV(); ep.NextB(); ep.FlipV();
      face::FFAttachManifold(f,2,epold.f,epold.z);
      np0=ep;  // assign the two new
      assert(!np0.v->IsUserBit(NonManifoldBit()));            
      np1.SetNull();  // pos that denote the ears
    }
    else // Standard Case.
    {
      np0=ep;
      if(np0.v->IsUserBit(NonManifoldBit())) np0.SetNull();
      np1=PosType(f,2,e1.v);
      if(np1.v->IsUserBit(NonManifoldBit())) np1.SetNull();
    }

    return true;
  }

};  // end TrivialEar Class

//Ear with FillHoleMinimumWeight's quality policy
template<class MESH> class MinimumWeightEar : public TrivialEar<MESH>
{
public:
  static float &DiedralWeight() { static float _dw=0.1f; return _dw;}
  typedef TrivialEar<MESH> TE;
  typename MESH::ScalarType dihedralRad;
  typename MESH::ScalarType aspectRatio;
  const char * Dump() {
    static char buf[200];
    if(this->IsConcave()) snprintf(buf,200,"Dihedral -(deg) %6.2f Quality %6.2f\n",math::ToDeg(dihedralRad),aspectRatio);
    else snprintf(buf,200,"Dihedral  (deg) %6.2f Quality %6.2f\n",math::ToDeg(dihedralRad),aspectRatio);
    return buf;
  }

  MinimumWeightEar(){}
  MinimumWeightEar(const typename face::Pos<typename MESH::FaceType>& ep) : TrivialEar<MESH>(ep)
  {
    ComputeQuality();
  }

  // In the heap, by default, we retrieve the LARGEST value,
  // so if we need the ear with minimal dihedral angle, we must reverse the sign of the comparison.
  // The concave elements must be all in the end of the heap, sorted accordingly,
  // So if only one of the two ear is Concave that one is always the minimum one.
  // the pow function is here just to give a way to play with different weighting schemas, balancing in a different way

  virtual inline bool operator <  ( const MinimumWeightEar & c ) const
  {
    if(TE::IsConcave()  && ! c.IsConcave() ) return true;
    if(!TE::IsConcave()  &&  c.IsConcave() ) return false;

    return aspectRatio - (dihedralRad/M_PI)*DiedralWeight() < c.aspectRatio -(c.dihedralRad/M_PI)*DiedralWeight();

//      return (pow((float)dihedralRad,(float)DiedralWeight())/aspectRatio) > (pow((float)c.dihedralRad,(float)DiedralWeight())/c.aspectRatio);
  }

  // the real core of the whole hole filling strategy.
  virtual void ComputeQuality()
  {
    //compute quality by (dihedral ancgle, area/sum(edge^2) )
    typename MESH::CoordType  n1=TE::e0.FFlip()->cN();
    typename MESH::CoordType n2=TE::e1.FFlip()->cN();

    dihedralRad = std::max(Angle(TE::n,n1),Angle(TE::n,n2));
    aspectRatio = QualityFace(*this);
  }

};  // end class MinimumWeightEar


//Ear for selfintersection algorithm
template<class MESH> class SelfIntersectionEar : public MinimumWeightEar<MESH>
{
public:
  typedef typename MESH::FaceType FaceType;
  typedef typename MESH::FacePointer FacePointer;
  typedef typename face::Pos<FaceType>    PosType;
  typedef typename MESH::ScalarType ScalarType;
  typedef typename MESH::CoordType CoordType;

  static std::vector<FacePointer> &AdjacencyRing()
  {
    static std::vector<FacePointer> ar;
    return ar;
  }

  SelfIntersectionEar(){}
  SelfIntersectionEar(const PosType & ep):MinimumWeightEar<MESH>(ep){}

  virtual bool Close(PosType &np0, PosType &np1, FacePointer f)
  {
    PosType	ep=this->e0; ep.FlipV(); ep.NextB(); ep.FlipV(); // he precedente a e0
    PosType	en=this->e1; en.NextB();	// he successivo a e1
//    bool triangularHole = false;
//    if(en==ep || en-) triangularHole=true;


    //costruisco la faccia e poi testo, o copio o butto via.
    (*f).V(0) = this->e0.VFlip();
    (*f).V(1) = this->e0.v;
    (*f).V(2) = this->e1.v;
    face::FFSetBorder(f,0);
    face::FFSetBorder(f,1);
    face::FFSetBorder(f,2);

    typename std::vector< FacePointer >::iterator it;
    for(it = this->AdjacencyRing().begin();it!= this->AdjacencyRing().end();++it)
    {
      if(!(*it)->IsD())
      {
        if(	tri::Clean<MESH>::TestFaceFaceIntersection(f,*it))
          return false;
        // We must also check that the newly created face does not have any edge in common with other existing surrounding faces
        // Only the two faces of the ear can share an edge with the new face
        if(face::CountSharedVertex(f,*it)==2)
        {
          int e0,e1;
          bool ret=face::FindSharedEdge(f,*it,e0,e1);
          assert(ret); (void)ret;
          if(!face::IsBorder(**it,e1))
            return false;
        }
      }
    }
    bool ret=TrivialEar<MESH>::Close(np0,np1,f);
    if(ret) AdjacencyRing().push_back(f);
    return ret;
  }
}; // end class SelfIntersectionEar



/** Hole
 * Main hole filling templated class. 
 * 
 */
template <class MESH>
class Hole
{
public:
  typedef typename MESH::VertexType				VertexType;
  typedef typename MESH::VertexPointer		VertexPointer;
  typedef	typename MESH::ScalarType				ScalarType;
  typedef typename MESH::FaceType					FaceType;
  typedef typename MESH::FacePointer			FacePointer;
  typedef typename MESH::FaceIterator			FaceIterator;
  typedef typename MESH::CoordType				CoordType;
  typedef typename vcg::Box3<ScalarType>  Box3Type;
  typedef typename face::Pos<FaceType>    PosType;
  
public:

  class Info
  {
  public:
    Info(){}
    Info(PosType const &pHole, int  const pHoleSize, Box3<ScalarType> &pHoleBB)
    {
      p=pHole;
      size=pHoleSize;
      bb=pHoleBB;
    }
    
    PosType p;
    int size;
    Box3Type  bb;
    
    bool operator <  (const  Info & hh) const {return size <  hh.size;}
    
    ScalarType Perimeter()
    {
      ScalarType sum=0;
      PosType ip = p;
      do
      {
        sum+=Distance(ip.v->cP(),ip.VFlip()->cP());
        ip.NextB();
      }
      while (ip != p);
      return sum;
    }
    
    // Support function to test the validity of a single hole loop
    // for now it test only that all the edges are border;
    // The real test should check if all non manifold vertices
    // are touched only by edges belonging to this hole loop.
    bool CheckValidity()
    {
      if(!p.IsBorder())
        return false;
      PosType ip=p;ip.NextB();
      for(;ip!=p;ip.NextB())
      {
        if(!ip.IsBorder())
          return false;
      }
      return true;
    }
  };

               
/** FillHoleEar
 * Main Single Hole Filling Function                         
 * Given a specific hole (identified by the Info h) it fills it 
 * It also update a vector of face pointers                     
 * It uses a priority queue to choose the best ear to be closed          
 */
        
template<class EAR>
    static void FillHoleEar(MESH &m, // The mesh to be filled
                            const PosType &p, // the particular hole to be filled
                            std::vector<FacePointer *> &facePointersToBeUpdated)
    {
      
      assert(tri::IsValidPointer(m,p.f));
      assert(p.IsBorder());
      int holeSize = EAR::InitNonManifoldBitOnHoleBoundary(p);
      FaceIterator f = tri::Allocator<MESH>::AddFaces(m, holeSize-2, facePointersToBeUpdated);

      std::priority_queue< EAR > EarHeap;
      PosType fp = p;
      do{
        EAR appEar = EAR(fp);
        if(!fp.v->IsUserBit(EAR::NonManifoldBit()))
           EarHeap.push( appEar );
        //printf("Adding ear %s ",app.Dump());
        fp.NextB();
        assert(fp.IsBorder());
      }while(fp!=p);

      // Main Ear closing Loop
      while( holeSize > 2 && !EarHeap.empty() )
      {
        EAR BestEar=EarHeap.top();
        EarHeap.pop();

        if(BestEar.IsUpToDate() && !BestEar.IsDegen())
        {
          if((*f).HasPolyInfo()) (*f).Alloc(3);
          PosType ep0,ep1;
          if(BestEar.Close(ep0,ep1,&*f))
          {
            if(!ep0.IsNull()){
              assert(!ep0.v->IsUserBit(EAR::NonManifoldBit()));
              EarHeap.push(EAR(ep0));
            }
            if(!ep1.IsNull()){
              assert(!ep1.v->IsUserBit(EAR::NonManifoldBit()));
              EarHeap.push(EAR(ep1));
            }
            --holeSize;
            ++f;
          }
        }//is update()
      } 
      
      // If the hole had k non manifold vertexes it requires less than n-2 face ( it should be n - 2*(k+1) ), 
      // so we delete the remaining ones. 
      while(f!=m.face.end()){
        tri::Allocator<MESH>::DeleteFace(m,*f);
        f++;
      }
    }

    template<class EAR>
    static int EarCuttingFill(MESH &m, int sizeHole, bool Selected = false, CallBackPos *cb=0)
    {
      std::vector< Info > vinfo;
      GetInfo(m, Selected,vinfo);

      typename std::vector<Info >::iterator ith;
      int indCb=0;
      int holeCnt=0;
      std::vector<FacePointer *> facePtrToBeUpdated;
      for(ith = vinfo.begin(); ith!= vinfo.end(); ++ith)
        facePtrToBeUpdated.push_back( &(*ith).p.f );

      for(ith = vinfo.begin(); ith!= vinfo.end(); ++ith)
      {
        indCb++;
        if(cb) (*cb)(indCb*10/vinfo.size(),"Closing Holes");
        if((*ith).size < sizeHole){
          holeCnt++;
          FillHoleEar< EAR >(m, (*ith).p,facePtrToBeUpdated);
        }
      }
      return holeCnt;
    }

/// Main Hole Filling function.
/// Given a mesh search for all the holes smaller than a given size and fill them
/// It returns the number of filled holes.

template<class EAR>
    static int EarCuttingIntersectionFill(MESH &m, const int maxSizeHole, bool Selected, CallBackPos *cb=0)
    {
      std::vector<Info > vinfo;
      GetInfo(m, Selected,vinfo);
      typename std::vector<Info>::iterator ith;

      // collect the face pointer that has to be updated by the various addfaces
      std::vector<FacePointer *> vfpOrig;
      for(ith = vinfo.begin(); ith!= vinfo.end(); ++ith)
        vfpOrig.push_back( &(*ith).p.f );

      int indCb=0;
      int holeCnt=0;
      for(ith = vinfo.begin(); ith!= vinfo.end(); ++ith)
      {
        indCb++;
        if(cb) (*cb)(indCb*10/vinfo.size(),"Closing Holes");
        if((*ith).size < maxSizeHole){
          std::vector<FacePointer *> facePtrToBeUpdated;
          holeCnt++;
          facePtrToBeUpdated=vfpOrig;
          EAR::AdjacencyRing().clear();
          //Loops around the hole to collect the faces that have to be tested for intersection.
          PosType ip = (*ith).p;
          do
          {
            PosType inp = ip;
            do
            {
              inp.FlipE();
              inp.FlipF();
              EAR::AdjacencyRing().push_back(inp.f);
            } while(!inp.IsBorder());
            ip.NextB();
          }while(ip != (*ith).p);

          typename std::vector<FacePointer>::iterator fpi;
          for(fpi=EAR::AdjacencyRing().begin();fpi!=EAR::AdjacencyRing().end();++fpi)
            facePtrToBeUpdated.push_back( &*fpi );

          FillHoleEar<EAR >(m, ith->p,facePtrToBeUpdated);
          EAR::AdjacencyRing().clear();
        }
      }
      return holeCnt;
    }



    static void GetInfo(MESH &m, bool Selected ,std::vector<Info >& VHI)
        {
      tri::UpdateFlags<MESH>::FaceClearV(m);
            for(FaceIterator fi = m.face.begin(); fi!=m.face.end(); ++fi)
            {
                if(!(*fi).IsD())
                {
                    if(Selected && !(*fi).IsS())
                    {
                        //se devo considerare solo i triangoli selezionati e
                        //quello che sto considerando non lo e' lo marchio e vado avanti
                      (*fi).SetV();
                    }
                    else
                    {
                            for(int j =0; j<3 ; ++j)
                            {
                              if( face::IsBorder(*fi,j) && !(*fi).IsV() )
                                {//Trovato una faccia di bordo non ancora visitata.
                                    (*fi).SetV();
                                PosType sp(&*fi, j, (*fi).V(j));
                                    PosType fp=sp;
                                    int holesize=0;

                                    Box3Type hbox;
                                    hbox.Add(sp.v->cP());
                  //printf("Looping %i : (face %i edge %i) \n", VHI.size(),sp.f-&*m.face.begin(),sp.z);
                                    sp.f->SetV();
                                    do
                                    {
                                        sp.f->SetV();
                                        hbox.Add(sp.v->cP());
                                        ++holesize;
                                        sp.NextB();
                                        sp.f->SetV();
                                        assert(sp.IsBorder());
                                    }while(sp != fp);

                                    //ho recuperato l'inofrmazione su tutto il buco
                                    VHI.push_back( Info(sp,holesize,hbox) );
                                }
                            }//for sugli edge del triangolo
                    }//S & !S
                }//!IsD()
            }//for principale!!!
        }

        //Minimum Weight Algorithm
        class Weight
        {
        public:

            Weight() { ang = 180; ar = FLT_MAX ;}
            Weight( float An, float Ar ) { ang=An ; ar= Ar;}
            ~Weight() {}

            float angle() const { return ang; }
            float area()  const { return ar; }

            Weight operator+( const Weight & other ) const {return Weight( std::max( angle(), other.angle() ), area() + other.area());}
            bool operator<( const Weight & rhs ) const {return ( angle() < rhs.angle() ||(angle() == rhs.angle() && area() < rhs.area()));	}

        private:
            float ang;
            float ar;
        };

        /*
    \ /        \/
   v1*---------*v4
    / \       /
   /   \     /
  / 	  \   /
 /ear	   \ /
*---------*-
| v3      v2\
*/

    static float ComputeDihedralAngle(CoordType  p1,CoordType  p2,CoordType  p3,CoordType  p4)
        {
            CoordType  n1 = Normal(p1,p3,p2);
            CoordType  n2 = Normal(p1,p2,p4);
            return  math::ToDeg(AngleN(n1,n2));
        }

  static bool existEdge(PosType pi,PosType pf)
        {
            PosType app = pi;
            PosType appF = pi;
            PosType tmp;
            assert(pi.IsBorder());
            appF.NextB();
            appF.FlipV();
            do
            {
                tmp = app;
                tmp.FlipV();
                if(tmp.v == pf.v)
                    return true;
                app.FlipE();
                app.FlipF();

                if(app == pi)return false;
            }while(app != appF);
            return false;
        }

  static Weight computeWeight( int i, int j, int k,
                               std::vector<PosType > pv,
                               std::vector< std::vector< int > >  v)
  {
    PosType pi = pv[i];
    PosType pj = pv[j];
    PosType pk = pv[k];
    
    //test complex edge
    if(existEdge(pi,pj) || existEdge(pj,pk)|| existEdge(pk,pi)	)
    {
      return Weight();
    }
    // Return an infinite weight, if one of the neighboring patches
    // could not be created.
    if(v[i][j] == -1){return Weight();}
    if(v[j][k] == -1){return Weight();}
    
    //calcolo il massimo angolo diedrale, se esiste.
    float angle = 0.0f;
    PosType px;
    if(i + 1 == j)
    {
      px = pj;
      px.FlipE(); px.FlipV();
      angle = std::max<float>(angle , ComputeDihedralAngle(pi.v->P(), pj.v->P(), pk.v->P(), px.v->P())	);
    }
    else
    {
      angle = std::max<float>( angle, ComputeDihedralAngle(pi.v->P(),pj.v->P(), pk.v->P(), pv[ v[i][j] ].v->P()));
    }
    
    if(j + 1 == k)
    {
      px = pk;
      px.FlipE(); px.FlipV();
      angle = std::max<float>(angle , ComputeDihedralAngle(pj.v->P(), pk.v->P(), pi.v->P(), px.v->P())	);
    }
    else
    {
      angle = std::max<float>( angle, ComputeDihedralAngle(pj.v->P(),pk.v->P(), pi.v->P(), pv[ v[j][k] ].v->P()));
    }
    
    if( i == 0 && k == (int)v.size() - 1)
    {
      px = pi;
      px.FlipE(); px.FlipV();
      angle = std::max<float>(angle , ComputeDihedralAngle(pk.v->P(), pi.v->P(),  pj.v->P(),px.v->P() )	);
    }
    
    ScalarType area = ( (pj.v->P() - pi.v->P()) ^ (pk.v->P() - pi.v->P()) ).Norm() * 0.5;
    
    return Weight(angle, area);
  }
  
  static void calculateMinimumWeightTriangulation(MESH &m, FaceIterator f,std::vector<PosType > vv )
  {
    std::vector< std::vector< Weight > > w; //matrice dei pesi minimali di ogni orecchio preso in conzideraione
    std::vector< std::vector< int    > > vi;//memorizza l'indice del terzo vertice del triangolo
    
    //hole size
    int nv = vv.size();
    
    w.clear();
    w.resize( nv, std::vector<Weight>( nv, Weight() ) );
    
    vi.resize( nv, std::vector<int>( nv, 0 ) );
    
    //inizializzo tutti i pesi possibili del buco
    for ( int i = 0; i < nv-1; ++i )
      w[i][i+1] = Weight( 0, 0 );
    
    //doppio ciclo for per calcolare di tutti i possibili triangoli i loro pesi.
    for ( int j = 2; j < nv; ++j )
    {
      for ( int i = 0; i + j < nv; ++i )
      {
        //per ogni triangolazione mi mantengo il minimo valore del peso tra i triangoli possibili
        Weight minval;
        
        //indice del vertice che da il peso minimo nella triangolazione corrente
        int minIndex = -1;
        
        //ciclo tra i vertici in mezzo a i due prefissati
        for ( int m = i + 1; m < i + j; ++m )
        {
          Weight a = w[i][m];
          Weight b = w[m][i+j];
          Weight newval =  a + b + computeWeight( i, m, i+j, vv, vi);
          if ( newval < minval )
          {
            minval = newval;
            minIndex = m;
          }
        }
        w[i][i+j] = minval;
        vi[i][i+j] = minIndex;
      }
    }
    
    //Triangulate
    int i, j;
    i=0; j=nv-1;
    
    triangulate(m,f, i, j, vi, vv);
    
    while(f!=m.face.end())
    {
      (*f).SetD();
      ++f;
      m.fn--;
    }
  }
  
  
  static void triangulate(MESH &m, FaceIterator &f,int i, int j,
                          std::vector< std::vector<int> > vi, std::vector<PosType > vv)
  {
    if(i + 1 == j){return;}
    if(i==j)return;
    
    int k = vi[i][j];
    
    if(k == -1)	return;
    
    //Setto i vertici
    f->V(0) = vv[i].v;
    f->V(1) = vv[k].v;
    f->V(2) = vv[j].v;
    
    f++;
    triangulate(m,f,i,k,vi,vv);
    triangulate(m,f,k,j,vi,vv);
  }
  
  static void MinimumWeightFill(MESH &m, int holeSize, bool Selected)
  {
    std::vector<PosType > vvi;
    std::vector<FacePointer * > vfp;
    
    std::vector<Info > vinfo;
    typename std::vector<Info >::iterator VIT;
    GetInfo(m, Selected,vinfo);
    
    for(VIT = vinfo.begin(); VIT != vinfo.end();++VIT)
    {
      vvi.push_back(VIT->p);
    }
    
    typename std::vector<PosType >::iterator ith;
    typename std::vector<PosType >::iterator ithn;
    typename std::vector<VertexPointer >::iterator itf;
    
    std::vector<PosType > app;
    PosType ps;
    std::vector<FaceType > tr;
    std::vector<VertexPointer > vf;
    
    for(ith = vvi.begin(); ith!= vvi.end(); ++ith)
    {
      tr.clear();
      vf.clear();
      app.clear();
      vfp.clear();
      
      ps = *ith;
      getBoundHole(ps,app);
      
      if(app.size() <= size_t(holeSize) )
      {
        typename std::vector<PosType >::iterator itP;
        std::vector<FacePointer *> vfp;
        
        for(ithn = vvi.begin(); ithn!= vvi.end(); ++ithn)
          vfp.push_back(&(ithn->f));
        
        for(itP = app.begin (); itP != app.end ();++itP)
          vfp.push_back( &(*itP).f );
        
        //aggiungo le facce
        FaceIterator f = tri::Allocator<MESH>::AddFaces(m, (app.size()-2) , vfp);
        
        calculateMinimumWeightTriangulation(m,f, app);
      }
    }
    
  }
  
  static void getBoundHole (PosType sp,std::vector<PosType >&ret)
  {
    PosType fp = sp;
    //take vertex around the hole
    do
    {
      assert(fp.IsBorder());
      ret.push_back(fp);
      fp.NextB();
    }while(sp != fp);
  }
  
};// class Hole

} // end namespace tri
} // end namespace vcg
#endif
