/***************************************************************************
 *   Copyright (c) 2005 Imetric 3D GmbH                                    *
 *                                                                         *
 *   This file is part of the FreeCAD CAx development system.              *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Library General Public           *
 *   License as published by the Free Software Foundation; either          *
 *   version 2 of the License, or (at your option) any later version.      *
 *                                                                         *
 *   This library  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 Library General Public License for more details.                  *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this library; see the file COPYING.LIB. If not,    *
 *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
 *   Suite 330, Boston, MA  02111-1307, USA                                *
 *                                                                         *
 ***************************************************************************/


#ifndef MESH_TOOLS_H
#define MESH_TOOLS_H

#include <functional>

#include <Mod/Mesh/App/WildMagic4/Wm4DistVector3Triangle3.h>
#include <Mod/Mesh/App/WildMagic4/Wm4Sphere3.h>
#include <Mod/Mesh/App/WildMagic4/Wm4Triangle3.h>

#include "MeshKernel.h"
#include "Algorithm.h"
#include "Iterator.h"

namespace MeshCore {

/**
 * The MeshSearchNeighbours class provides methods to get all points
 * in the neighbourhood of a given facet.
 */
class MeshSearchNeighbours 
{
public:
  MeshSearchNeighbours ( const MeshKernel &rclM, float fSampleDistance = 1.0f);
  virtual ~MeshSearchNeighbours () {}
  /** Re-initilaizes internal structures. */
  void Reinit (float fSampleDistance);
  /** Collects all neighbour points from the facet (by index), the result are the points of the facets lying
   * inside a sphere of radius \a fDistance, center \a center of the original facet. This method uses the 
   * MARKED flags.
   */
  unsigned long  NeighboursFromFacet (unsigned long ulFacetIdx, float fDistance, unsigned long ulMinPoints, std::vector<Base::Vector3f> &raclResultPoints);
  /** Searches for facets from the start facet, sample the neighbour facets and accumulates the points. */
  unsigned long  NeighboursFromSampledFacets (unsigned long ulFacetIdx, float fDistance, std::vector<Base::Vector3f> &raclResultPoints);
  /** Searches for facets from the start facet. */
  unsigned long  NeighboursFacetFromFacet (unsigned long ulFacetIdx, float fDistance, std::vector<Base::Vector3f> &raclResultPoints,
                                           std::vector<unsigned long> &raclResultFacets);

protected:
  /** Subsamples the mesh. */
  void SampleAllFacets (void);
  inline bool CheckDistToFacet (const MeshFacet &rclF);     // check distance to facet, add points inner radius
  bool AccumulateNeighbours (const MeshFacet &rclF, unsigned long ulFIdx); // accumulate the sample neighbours facet
  inline bool InnerPoint (const Base::Vector3f &rclPt) const;
  inline bool TriangleCutsSphere (const MeshFacet &rclF) const;
  bool ExpandRadius (unsigned long ulMinPoints);

  struct CDistRad : public std::binary_function<const Base::Vector3f&, const Base::Vector3f&, bool>
  {
    CDistRad (const Base::Vector3f clCenter) : _clCenter(clCenter) {}
    bool operator()(const Base::Vector3f &rclPt1, const Base::Vector3f &rclPt2) { return Base::DistanceP2(_clCenter, rclPt1) < Base::DistanceP2(_clCenter, rclPt2); }
    Base::Vector3f  _clCenter;
  };

protected:
  const MeshKernel  &_rclMesh;
  const MeshFacetArray &_rclFAry;
  const MeshPointArray &_rclPAry;
  MeshRefPointToFacets _clPt2Fa;
  float _fMaxDistanceP2;   // square distance 
  Base::Vector3f _clCenter;         // center points of start facet
  std::set<unsigned long> _aclResult;        // result container (point indices)
  std::set<unsigned long> _aclOuter;         // next searching points
  std::vector<Base::Vector3f> _aclPointsResult;  // result as vertex
  std::vector<std::vector<Base::Vector3f> > _aclSampledFacets; // sample points from each facet
  float _fSampleDistance;  // distance between two sampled points
  Wm4::Sphere3<float> _akSphere;
  bool _bTooFewPoints;    

private:
  MeshSearchNeighbours (const MeshSearchNeighbours&);
  void operator = (const MeshSearchNeighbours&);
};

inline bool MeshSearchNeighbours::CheckDistToFacet (const MeshFacet &rclF)
{
  bool bFound = false;

  for (int i = 0; i < 3; i++)
  {
    unsigned long ulPIdx = rclF._aulPoints[i];
    if (_rclPAry[ulPIdx].IsFlag(MeshPoint::MARKED) == false)
    {
      if (Base::DistanceP2(_clCenter, _rclPAry[ulPIdx]) < _fMaxDistanceP2)
      {
        bFound = true;
        {
          _aclResult.insert(ulPIdx);
          _rclPAry[ulPIdx].SetFlag(MeshPoint::MARKED);
        }
      }
      _aclOuter.insert(ulPIdx);
    }
  }

  return bFound;
}

inline bool MeshSearchNeighbours::InnerPoint (const Base::Vector3f &rclPt) const
{
  return Base::DistanceP2(_clCenter, rclPt) < _fMaxDistanceP2;
}

inline bool MeshSearchNeighbours::TriangleCutsSphere (const MeshFacet &rclF) const
{
  Base::Vector3f cP0 = _rclPAry[rclF._aulPoints[0]];
  Base::Vector3f cP1 = _rclPAry[rclF._aulPoints[1]];
  Base::Vector3f cP2 = _rclPAry[rclF._aulPoints[2]];

  Wm4::Vector3<float> akP0(cP0.x, cP0.y, cP0.z);
  Wm4::Vector3<float> akP1(cP1.x, cP1.y, cP1.z);
  Wm4::Vector3<float> akP2(cP2.x, cP2.y, cP2.z);

  Wm4::Triangle3<float> akTri(akP0, akP1, akP2);
  Wm4::DistVector3Triangle3<float> akDistVecTri(_akSphere.Center, akTri);

  float fSqrDist = akDistVecTri.GetSquared();
  float fRSqr = _akSphere.Radius*_akSphere.Radius;
  return fSqrDist < fRSqr;
}

class MeshFaceIterator : public std::unary_function<unsigned long, Base::Vector3f>
{
public:
    MeshFaceIterator(const MeshKernel& mesh)
        : it(mesh) {}
    Base::Vector3f operator() (unsigned long index)
    {
        it.Set(index);
        return it->GetGravityPoint();
    }

private:
    MeshFacetIterator it;
};

class MeshVertexIterator : public std::unary_function<unsigned long, Base::Vector3f>
{
public:
    MeshVertexIterator(const MeshKernel& mesh)
        : it(mesh) {}
    Base::Vector3f operator() (unsigned long index)
    {
        it.Set(index);
        return *it;
    }

private:
    MeshPointIterator it;
};

template <class T>
class MeshNearestIndexToPlane : public std::unary_function<unsigned long, void>
{
public:
    MeshNearestIndexToPlane(const MeshKernel& mesh, const Base::Vector3f& b, const Base::Vector3f& n)
        : nearest_index(ULONG_MAX),nearest_dist(FLOAT_MAX), it(mesh), base(b), normal(n) {}
    void operator() (unsigned long index)
    {
        float dist = (float)fabs(it(index).DistanceToPlane(base, normal));
        if (dist < nearest_dist) {
            nearest_dist = dist;
            nearest_index = index;
        }
    }

    unsigned long nearest_index;
    float nearest_dist;

private:
    T it;
    Base::Vector3f base, normal;
};

} // namespace MeshCore


#endif  // MESH_TOOLS_H