/****************************************************************************
* VCGLib                                                            o o     *
* Visual and Computer Graphics Library                            o     o   *
*                                                                _   O  _   *
* Copyright(C) 2004-2016                                           \/)\/    *
* Visual Computing Lab                                            /\/|      *
* ISTI - Italian National Research Council                           |      *
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* All rights reserved.                                                      *
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* This program is free software; you can redistribute it and/or modify      *   
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* (at your option) any later version.                                       *
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* 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.                                                         *
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****************************************************************************/

///** Returns the closest posistion of a point _p and its distance
//@param _p a 3d point
//@param _maxDist maximum distance not to search beyond.
//@param _getPointDistance (templated type) a functor object used to calculate distance from a grid object to the point _p.
//@param _minDist the returned closest distance
//@param _closestPt the returned closest point
//@return The closest element
//*/
///*
//	A DISTFUNCT object must implement an operator () with signature:
//		bool operator () (const ObjType& obj, const CoordType & _p, ScalarType & min_dist, CoordType & _closestPt);
//*/
#ifndef __VCGLIB_GRID_CLOSEST
#define __VCGLIB_GRID_CLOSEST

#include <vcg/space/index/space_iterators.h>

namespace vcg{

  template <class SPATIAL_INDEX, class OBJPOINTDISTFUNCTOR, class OBJMARKER>
    typename SPATIAL_INDEX::ObjPtr  GridClosest(SPATIAL_INDEX &Si,
    OBJPOINTDISTFUNCTOR _getPointDistance,
    OBJMARKER & _marker,
    const typename OBJPOINTDISTFUNCTOR::QueryType  & _p_obj,
    const typename SPATIAL_INDEX::ScalarType & _maxDist,
    typename SPATIAL_INDEX::ScalarType & _minDist,
    typename SPATIAL_INDEX:: CoordType &_closestPt)
  {
    typedef typename SPATIAL_INDEX::ObjPtr ObjPtr;
    typedef typename SPATIAL_INDEX::CoordType CoordType;
    typedef typename SPATIAL_INDEX::ScalarType ScalarType;
    typedef typename SPATIAL_INDEX::Box3x Box3x;

    Point3<ScalarType> _p = OBJPOINTDISTFUNCTOR::Pos(_p_obj);
    // Initialize min_dist with _maxDist to exploit early rejection test.
    _minDist = _maxDist;

    ObjPtr winner=NULL;
    _marker.UnMarkAll();
    ScalarType newradius = Si.voxel.Norm();
    ScalarType radius;
    Box3i iboxdone,iboxtodo;
    CoordType t_res;
    typename SPATIAL_INDEX::CellIterator first,last,l;
    if(Si.bbox.IsInEx(_p))
    {
      Point3i _ip;
      Si.PToIP(_p,_ip);
      Si.Grid( _ip[0],_ip[1],_ip[2], first, last );
      for(l=first;l!=last;++l)
      {
        ObjPtr elem=&(**l);
        if (!elem->IsD())
        {
          if (_getPointDistance((**l), _p_obj,_minDist, t_res))  // <-- NEW: use of distance functor
          {
            winner=elem;
            _closestPt=t_res;
            newradius=_minDist; //
          }
          _marker.Mark(elem);
        }
      }
      iboxdone=Box3i(_ip,_ip);
    }

    int ix,iy,iz;
    Box3i ibox(Point3i(0,0,0),Si.siz-Point3i(1,1,1));
    do
    {
      radius=newradius;
      Box3x boxtodo=Box3x(_p,radius);
      //boxtodo.Intersect(Si.bbox);
      Si.BoxToIBox(boxtodo, iboxtodo);
      iboxtodo.Intersect(ibox);
      if(!boxtodo.IsNull())
      {
        for (ix=iboxtodo.min[0]; ix<=iboxtodo.max[0]; ix++)
          for (iy=iboxtodo.min[1]; iy<=iboxtodo.max[1]; iy++)
            for (iz=iboxtodo.min[2]; iz<=iboxtodo.max[2]; iz++)
              if(ix<iboxdone.min[0] || ix>iboxdone.max[0] ||  // this test is to avoid to re-process already analyzed cells.
                iy<iboxdone.min[1] || iy>iboxdone.max[1] ||
                iz<iboxdone.min[2] || iz>iboxdone.max[2] )
              {
                Si.Grid( ix, iy, iz, first, last );
                for(l=first;l!=last;++l) if (!(**l).IsD())
                {
                  ObjPtr elem=&(**l);
                  if (!elem->IsD())
                  {
                    if( ! _marker.IsMarked(elem))
                    {
                      if (_getPointDistance((**l), _p_obj, _minDist, t_res))
                      {
                        winner=elem;
                        _closestPt=t_res;
                      };
                      _marker.Mark(elem);
                    }
                  }
                }
              }
      }
      if(!winner) newradius=radius+Si.voxel.Norm();
      else newradius = _minDist;
      iboxdone=iboxtodo;
    }
    while (_minDist>radius);

    return winner;
  }

  template <class SPATIALINDEXING,class OBJPOINTDISTFUNCTOR, class OBJMARKER,
  class OBJPTRCONTAINER, class DISTCONTAINER, class POINTCONTAINER>
    unsigned int GridGetKClosest(SPATIALINDEXING &_Si,
                   OBJPOINTDISTFUNCTOR & _getPointDistance,
                   OBJMARKER & _marker,
                   const unsigned int _k,
                   const typename SPATIALINDEXING::CoordType & _p,
                   const typename SPATIALINDEXING::ScalarType & _maxDist,
                   OBJPTRCONTAINER & _objectPtrs,
                   DISTCONTAINER & _distances,
                   POINTCONTAINER & _points)
  {
    typedef vcg::ClosestIterator<SPATIALINDEXING,OBJPOINTDISTFUNCTOR,OBJMARKER> ClosestIteratorType;
    ClosestIteratorType	Cli=ClosestIteratorType(_Si,_getPointDistance);
    Cli.SetMarker(_marker);
    Cli.Init(_p,_maxDist);
    unsigned int i=0;
    _objectPtrs.clear();
    _distances.clear();
    _points.clear();
    while ((!Cli.End())&&(i<_k))
    {
      _objectPtrs.push_back(&(*Cli));
      _distances.push_back(Cli.Dist());
      _points.push_back(Cli.NearestPoint());
      ++Cli;
      i++;
    }
    return (i);
  }

  template <class SPATIALINDEXING,class OBJRAYISECTFUNCTOR, class OBJMARKER>
    typename SPATIALINDEXING::ObjPtr GridDoRay(SPATIALINDEXING &_Si,
                           OBJRAYISECTFUNCTOR &_rayIntersector,
                           OBJMARKER &_marker,
                           const Ray3<typename SPATIALINDEXING::ScalarType> & _ray,
                           const typename SPATIALINDEXING::ScalarType & _maxDist,
                           typename SPATIALINDEXING::ScalarType & _t)
  {
    typedef vcg::RayIterator<SPATIALINDEXING,OBJRAYISECTFUNCTOR,OBJMARKER> RayIteratorType;
    RayIteratorType RayIte=RayIteratorType(_Si,_rayIntersector,_maxDist);
    RayIte.SetMarker(_marker);
    RayIte.Init(_ray);

    if (!RayIte.End())
    {
      _t=RayIte.Dist();
      return(&(*RayIte));
    }
    return 0;
  }


  template <class SPATIALINDEXING, class OBJPOINTDISTFUNCTOR, class OBJMARKER, class OBJPTRCONTAINER, class DISTCONTAINER, class POINTCONTAINER>
    unsigned int GridGetInSphere(SPATIALINDEXING &_Si,
                  OBJPOINTDISTFUNCTOR & _getPointDistance,
                  OBJMARKER & _marker,
                  const typename SPATIALINDEXING::CoordType & _p,
                  const typename SPATIALINDEXING::ScalarType & _r,
                  OBJPTRCONTAINER & _objectPtrs,
                  DISTCONTAINER & _distances,
                  POINTCONTAINER & _points)
  {
      typedef vcg::ClosestIterator<SPATIALINDEXING,OBJPOINTDISTFUNCTOR,OBJMARKER> ClosestIteratorType;
      ClosestIteratorType	Cli=ClosestIteratorType(_Si,_getPointDistance);
      Cli.SetMarker(_marker);
      Cli.Init(_p,_r);
      _objectPtrs.clear();
      _distances.clear();
      _points.clear();
      while (!Cli.End())
      {
        _objectPtrs.push_back(&(*Cli));
        _distances.push_back(Cli.Dist());
        _points.push_back(Cli.NearestPoint());
        ++Cli;
      }
      return ((int)_objectPtrs.size());
    }

    template <class SPATIALINDEXING,class OBJMARKER, class OBJPTRCONTAINER>
      unsigned int GridGetInBox(SPATIALINDEXING &_Si,
      OBJMARKER & _marker,
      const vcg::Box3<typename SPATIALINDEXING::ScalarType> &_bbox,
      OBJPTRCONTAINER & _objectPtrs)
    {
      typename SPATIALINDEXING::CellIterator first,last,l;
      _objectPtrs.clear();
      vcg::Box3i ibbox;
      Box3i Si_ibox(Point3i(0,0,0),_Si.siz-Point3i(1,1,1));
      _Si.BoxToIBox(_bbox, ibbox);
      ibbox.Intersect(Si_ibox);
      _marker.UnMarkAll();
      if (ibbox.IsNull())
        return 0;
      else
      {
        int ix,iy,iz;
        for (ix=ibbox.min[0]; ix<=ibbox.max[0]; ix++)
        {
          for (iy=ibbox.min[1]; iy<=ibbox.max[1]; iy++)
          {
            for (iz=ibbox.min[2]; iz<=ibbox.max[2]; iz++)
            {
              _Si.Grid( ix, iy, iz, first, last );
              for(l=first;l!=last;++l)
              {
                if (!(**l).IsD())
                {
                  typename SPATIALINDEXING::ObjPtr elem=&(**l);
                  vcg::Box3<typename SPATIALINDEXING::ScalarType> box_elem;
                  elem->GetBBox(box_elem);
                  if(( ! _marker.IsMarked(elem))&&(box_elem.Collide(_bbox)))
                  {
                    _objectPtrs.push_back(elem);
                    _marker.Mark(elem);
                  }
                }
              }
            }
          }
        }
        return (static_cast<unsigned int>(_objectPtrs.size()));
      }
    }

  }//end namespace vcg
#endif

