Mesh.cpp

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/***************************************************************************
 *   Copyright (c) Juergen Riegel         <juergen.riegel@web.de>          *
 *                                                                         *
 *   This file is part of the FreeCAD CAx development system.              *
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 *   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          *
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 *   This library  is distributed in the hope that it will be useful,      *
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 *   GNU Library General Public License for more details.                  *
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 ***************************************************************************/


#include "PreCompiled.h"
#ifndef _PreComp_
# include <algorithm>
# include <sstream>
#endif

#include <CXX/Objects.hxx>
#include <Base/Builder3D.h>
#include <Base/Console.h>
#include <Base/Exception.h>
#include <Base/Writer.h>
#include <Base/Reader.h>
#include <Base/Interpreter.h>

#include "Core/Builder.h"
#include "Core/MeshKernel.h"
#include "Core/Grid.h"
#include "Core/Iterator.h"
#include "Core/Info.h"
#include "Core/TopoAlgorithm.h"
#include "Core/Evaluation.h"
#include "Core/Degeneration.h"
#include "Core/SetOperations.h"
#include "Core/Visitor.h"

#include "Mesh.h"
#include "MeshPy.h"

using namespace Mesh;

float MeshObject::Epsilon = 1.0e-5f;

TYPESYSTEM_SOURCE(Mesh::MeshObject, Data::ComplexGeoData);

MeshObject::MeshObject()
{
}

MeshObject::MeshObject(const MeshCore::MeshKernel& Kernel)
  : _kernel(Kernel)
{
    // copy the mesh structure
}

MeshObject::MeshObject(const MeshCore::MeshKernel& Kernel, const Base::Matrix4D &Mtrx)
  : _Mtrx(Mtrx),_kernel(Kernel)
{
    // copy the mesh structure
}

MeshObject::MeshObject(const MeshObject& mesh)
  : _Mtrx(mesh._Mtrx),_kernel(mesh._kernel)
{
    // copy the mesh structure
    this->_segments = mesh._segments;
}

MeshObject::~MeshObject()
{
}

std::vector<const char*> MeshObject::getElementTypes(void) const
{
    std::vector<const char*> temp;
    temp.push_back("Face"); // that's the mesh itself
    temp.push_back("Segment");

    return temp;
}

unsigned long MeshObject::countSubElements(const char* Type) const
{
    std::string element(Type);
    if (element == "Face")
        return 1;
    else if (element == "Segment")
        return countSegments();
    return 0;
}

Data::Segment* MeshObject::getSubElement(const char* Type, unsigned long n) const
{
    //TODO
    std::string element(Type);
    if (element == "Face")
        return 0;
    else if (element == "Segment")
        return 0;
    return 0;
}

void MeshObject::getFacesFromSubelement(const Data::Segment* segm,
                                        std::vector<Base::Vector3d> &Points,
                                        std::vector<Base::Vector3d> &PointNormals,
                                        std::vector<Facet> &faces) const
{
    //TODO
    this->getFaces(Points, faces, 0.0f);
}

void MeshObject::transformGeometry(const Base::Matrix4D &rclMat)
{
    MeshCore::MeshKernel kernel;
    swap(kernel);
    kernel.Transform(rclMat);
    swap(kernel);
}

void MeshObject::setTransform(const Base::Matrix4D& rclTrf)
{
    _Mtrx = rclTrf;
}

Base::Matrix4D MeshObject::getTransform(void) const
{
    return _Mtrx;
}

Base::BoundBox3d MeshObject::getBoundBox(void)const
{
    const_cast<MeshCore::MeshKernel&>(_kernel).RecalcBoundBox();
    Base::BoundBox3f Bnd = _kernel.GetBoundBox();
    
    Base::BoundBox3d Bnd2;
    for(int i =0 ;i<=7;i++)
        Bnd2.Add(transformToOutside(Bnd.CalcPoint(i)));
    
    return Bnd2;
}

void MeshObject::operator = (const MeshObject& mesh)
{
    if (this != &mesh) {
        // copy the mesh structure
        setTransform(mesh._Mtrx);
        this->_kernel = mesh._kernel;
        this->_segments = mesh._segments;
    }
}

void MeshObject::setKernel(const MeshCore::MeshKernel& m)
{
    this->_kernel = m;
    this->_segments.clear();
}

void MeshObject::swap(MeshCore::MeshKernel& Kernel)
{
    this->_kernel.Swap(Kernel);
    // clear the segments because we don't know how the new
    // topology looks like
    this->_segments.clear();
}

void MeshObject::swap(MeshObject& mesh)
{
    this->_kernel.Swap(mesh._kernel);
    this->_segments.swap(mesh._segments);
    Base::Matrix4D tmp=this->_Mtrx;
    this->_Mtrx = mesh._Mtrx;
    mesh._Mtrx = tmp;
}

std::string MeshObject::representation() const
{
    std::stringstream str;
    MeshCore::MeshInfo info(_kernel);
    info.GeneralInformation(str);
    return str.str();
}

std::string MeshObject::topologyInfo() const
{
    std::stringstream str;
    MeshCore::MeshInfo info(_kernel);
    info.TopologyInformation(str);
    return str.str();
}

unsigned long MeshObject::countPoints() const
{
    return _kernel.CountPoints();
}

unsigned long MeshObject::countFacets() const
{
    return _kernel.CountFacets();
}

unsigned long MeshObject::countEdges () const
{
    return _kernel.CountEdges();
}

unsigned long MeshObject::countSegments () const
{
    return this->_segments.size();
}

bool MeshObject::isSolid() const
{
    MeshCore::MeshEvalSolid cMeshEval(_kernel);
    return cMeshEval.Evaluate();
}

double MeshObject::getSurface() const
{
    return _kernel.GetSurface();
}

double MeshObject::getVolume() const
{
    return _kernel.GetVolume();
}

MeshPoint MeshObject::getPoint(unsigned long index) const
{
    Base::Vector3f vertf = _kernel.GetPoint(index);
    Base::Vector3d vertd(vertf.x, vertf.y, vertf.z);
    vertd = _Mtrx * vertd;
    MeshPoint point(vertd, const_cast<MeshObject*>(this), index);
    return point;
}

Mesh::Facet MeshObject::getFacet(unsigned long index) const
{
    Mesh::Facet face(_kernel.GetFacets()[index], const_cast<MeshObject*>(this), index);
    return face;
}

void MeshObject::getFaces(std::vector<Base::Vector3d> &Points,std::vector<Facet> &Topo,
                          float Accuracy, uint16_t flags) const
{
    unsigned long ctpoints = _kernel.CountPoints();
    Points.reserve(ctpoints);
    for (unsigned long i=0; i<ctpoints; i++) {
        Points.push_back(this->getPoint(i));
    }

    unsigned long ctfacets = _kernel.CountFacets();
    const MeshCore::MeshFacetArray& ary = _kernel.GetFacets();
    Topo.reserve(ctfacets);
    for (unsigned long i=0; i<ctfacets; i++) {
        Facet face;
        face.I1 = (unsigned int)ary[i]._aulPoints[0];
        face.I2 = (unsigned int)ary[i]._aulPoints[1];
        face.I3 = (unsigned int)ary[i]._aulPoints[2];
        Topo.push_back(face);
    }
}

unsigned int MeshObject::getMemSize (void) const
{
    return _kernel.GetMemSize();
}

void MeshObject::Save (Base::Writer &writer) const
{
    // this is handled by the property class
}

void MeshObject::SaveDocFile (Base::Writer &writer) const
{
    _kernel.Write(writer.Stream());
}

void MeshObject::Restore(Base::XMLReader &reader)
{
    // this is handled by the property class
}

void MeshObject::RestoreDocFile(Base::Reader &reader)
{
    load(reader);
}

void MeshObject::save(const char* file, MeshCore::MeshIO::Format f,
                      const MeshCore::Material* mat) const
{
    MeshCore::MeshOutput aWriter(this->_kernel, mat);
    aWriter.Transform(this->_Mtrx);
    aWriter.SaveAny(file, f);
}

void MeshObject::save(std::ostream& out) const
{
    _kernel.Write(out);
}

bool MeshObject::load(const char* file)
{
    MeshCore::MeshKernel kernel;
    MeshCore::MeshInput aReader(kernel);
    if (!aReader.LoadAny(file))
        return false;

    _kernel.Swap(kernel);
    // Some file formats define several objects per file (e.g. OBJ).
    // Now we mark each object as an own segment so that we can break
    // the object into its orriginal objects again.
    this->_segments.clear();
    const MeshCore::MeshFacetArray& faces = _kernel.GetFacets();
    MeshCore::MeshFacetArray::_TConstIterator it;
    std::vector<unsigned long> segment;
    segment.reserve(faces.size());
    unsigned long prop = 0;
    unsigned long index = 0;
    for (it = faces.begin(); it != faces.end(); ++it) {
        if (prop < it->_ulProp) {
            prop = it->_ulProp;
            if (!segment.empty()) {
                this->_segments.push_back(Segment(this,segment,true));
                segment.clear();
            }
        }

        segment.push_back(index++);
    }

    // if the whole mesh is a single object then don't mark as segment
    if (!segment.empty() && (segment.size() < faces.size())) {
        this->_segments.push_back(Segment(this,segment,true));
    }

#ifndef FC_DEBUG
    try {
        MeshCore::MeshEvalNeighbourhood nb(_kernel);
        if (!nb.Evaluate()) {
            Base::Console().Warning("Errors in neighbourhood of mesh found...");
            _kernel.RebuildNeighbours();
            Base::Console().Warning("fixed\n");
        }

        MeshCore::MeshEvalTopology eval(_kernel);
        if (!eval.Evaluate()) {
            Base::Console().Warning("The mesh data structure has some defects\n");
        }
    }
    catch (const Base::MemoryException&) {
        // ignore memory exceptions and continue
        Base::Console().Log("Check for defects in mesh data structure failed\n");
    }
#endif

    return true;
}

void MeshObject::load(std::istream& in)
{
    _kernel.Read(in);
    this->_segments.clear();

#ifndef FC_DEBUG
    try {
        MeshCore::MeshEvalNeighbourhood nb(_kernel);
        if (!nb.Evaluate()) {
            Base::Console().Warning("Errors in neighbourhood of mesh found...");
            _kernel.RebuildNeighbours();
            Base::Console().Warning("fixed\n");
        }

        MeshCore::MeshEvalTopology eval(_kernel);
        if (!eval.Evaluate()) {
            Base::Console().Warning("The mesh data structure has some defects\n");
        }
    }
    catch (const Base::MemoryException&) {
        // ignore memory exceptions and continue
        Base::Console().Log("Check for defects in mesh data structure failed\n");
    }
#endif
}

void MeshObject::addFacet(const MeshCore::MeshGeomFacet& facet)
{
    _kernel.AddFacet(facet);
}

void MeshObject::addFacets(const std::vector<MeshCore::MeshGeomFacet>& facets)
{
    _kernel.AddFacets(facets);
}

void MeshObject::addFacets(const std::vector<MeshCore::MeshFacet> &facets)
{
    _kernel.AddFacets(facets);
}

void MeshObject::addFacets(const std::vector<MeshCore::MeshFacet> &facets,
                           const std::vector<Base::Vector3f>& points)
{
    _kernel.AddFacets(facets, points);
}

void MeshObject::addFacets(const std::vector<Data::ComplexGeoData::Facet> &facets,
                           const std::vector<Base::Vector3d>& points)
{
    std::vector<MeshCore::MeshFacet> facet_v;
    facet_v.reserve(facets.size());
    for (std::vector<Data::ComplexGeoData::Facet>::const_iterator it = facets.begin(); it != facets.end(); ++it) {
        MeshCore::MeshFacet f;
        f._aulPoints[0] = it->I1;
        f._aulPoints[1] = it->I2;
        f._aulPoints[2] = it->I3;
        facet_v.push_back(f);
    }

    std::vector<Base::Vector3f> point_v;
    point_v.reserve(points.size());
    for (std::vector<Base::Vector3d>::const_iterator it = points.begin(); it != points.end(); ++it) {
        Base::Vector3f p((float)it->x,(float)it->y,(float)it->z);
        point_v.push_back(p);
    }

    _kernel.AddFacets(facet_v, point_v);
}

void MeshObject::setFacets(const std::vector<MeshCore::MeshGeomFacet>& facets)
{
    _kernel = facets;
}

void MeshObject::setFacets(const std::vector<Data::ComplexGeoData::Facet> &facets,
                           const std::vector<Base::Vector3d>& points)
{
    MeshCore::MeshFacetArray facet_v;
    facet_v.reserve(facets.size());
    for (std::vector<Data::ComplexGeoData::Facet>::const_iterator it = facets.begin(); it != facets.end(); ++it) {
        MeshCore::MeshFacet f;
        f._aulPoints[0] = it->I1;
        f._aulPoints[1] = it->I2;
        f._aulPoints[2] = it->I3;
        facet_v.push_back(f);
    }

    MeshCore::MeshPointArray point_v;
    point_v.reserve(points.size());
    for (std::vector<Base::Vector3d>::const_iterator it = points.begin(); it != points.end(); ++it) {
        Base::Vector3f p((float)it->x,(float)it->y,(float)it->z);
        point_v.push_back(p);
    }

    _kernel.Adopt(point_v, facet_v, true);
}

void MeshObject::addMesh(const MeshObject& mesh)
{
    _kernel.Merge(mesh._kernel);
}

void MeshObject::addMesh(const MeshCore::MeshKernel& kernel)
{
    _kernel.Merge(kernel);
}

void MeshObject::deleteFacets(const std::vector<unsigned long>& removeIndices)
{
    _kernel.DeleteFacets(removeIndices);
    deletedFacets(removeIndices);
}

void MeshObject::deletePoints(const std::vector<unsigned long>& removeIndices)
{
    _kernel.DeletePoints(removeIndices);
    this->_segments.clear();
}

void MeshObject::deletedFacets(const std::vector<unsigned long>& remFacets)
{
    if (remFacets.empty())
        return; // nothing has changed
    if (this->_segments.empty())
        return; // nothing to do
    // set an array with the original indices and mark the removed as ULONG_MAX
    std::vector<unsigned long> f_indices(_kernel.CountFacets()+remFacets.size());
    for (std::vector<unsigned long>::const_iterator it = remFacets.begin();
        it != remFacets.end(); ++it) {
        f_indices[*it] = ULONG_MAX;
    }

    unsigned long index = 0;
    for (std::vector<unsigned long>::iterator it = f_indices.begin();
        it != f_indices.end(); ++it) {
            if (*it == 0)
                *it = index++;
    }

    // the array serves now as LUT to set the new indices in the segments
    for (std::vector<Segment>::iterator it = this->_segments.begin();
        it != this->_segments.end(); ++it) {
            std::vector<unsigned long> segm = it->_indices;
            for (std::vector<unsigned long>::iterator jt = segm.begin();
                jt != segm.end(); ++jt) {
                    *jt = f_indices[*jt];
            }

            // remove the invalid indices
            std::sort(segm.begin(), segm.end());
            std::vector<unsigned long>::iterator ft = std::find_if
                (segm.begin(), segm.end(), 
                std::bind2nd(std::equal_to<unsigned long>(), ULONG_MAX));
            if (ft != segm.end())
                segm.erase(ft, segm.end());
            it->_indices = segm;
    }
}

void MeshObject::deleteSelectedFacets()
{
    std::vector<unsigned long> facets;
    MeshCore::MeshAlgorithm(this->_kernel).GetFacetsFlag(facets, MeshCore::MeshFacet::SELECTED);
    deleteFacets(facets);
}

void MeshObject::deleteSelectedPoints()
{
    std::vector<unsigned long> points;
    MeshCore::MeshAlgorithm(this->_kernel).GetPointsFlag(points, MeshCore::MeshPoint::SELECTED);
    deletePoints(points);
}

void MeshObject::clearFacetSelection() const
{
    MeshCore::MeshAlgorithm(this->_kernel).ResetFacetFlag(MeshCore::MeshFacet::SELECTED);
}

void MeshObject::clearPointSelection() const
{
    MeshCore::MeshAlgorithm(this->_kernel).ResetPointFlag(MeshCore::MeshPoint::SELECTED);
}

void MeshObject::addFacetsToSelection(const std::vector<unsigned long>& inds) const
{
    MeshCore::MeshAlgorithm(this->_kernel).SetFacetsFlag(inds, MeshCore::MeshFacet::SELECTED);
}

void MeshObject::addPointsToSelection(const std::vector<unsigned long>& inds) const
{
    MeshCore::MeshAlgorithm(this->_kernel).SetPointsFlag(inds, MeshCore::MeshPoint::SELECTED);
}

void MeshObject::removeFacetsFromSelection(const std::vector<unsigned long>& inds) const
{
    MeshCore::MeshAlgorithm(this->_kernel).ResetFacetsFlag(inds, MeshCore::MeshFacet::SELECTED);
}

void MeshObject::removePointsFromSelection(const std::vector<unsigned long>& inds) const
{
    MeshCore::MeshAlgorithm(this->_kernel).ResetPointsFlag(inds, MeshCore::MeshPoint::SELECTED);
}

void MeshObject::getFacetsFromSelection(std::vector<unsigned long>& inds) const
{
    MeshCore::MeshAlgorithm(this->_kernel).GetFacetsFlag(inds, MeshCore::MeshFacet::SELECTED);
}

void MeshObject::getPointsFromSelection(std::vector<unsigned long>& inds) const
{
    MeshCore::MeshAlgorithm(this->_kernel).GetPointsFlag(inds, MeshCore::MeshPoint::SELECTED);
}

void MeshObject::updateMesh(const std::vector<unsigned long>& facets)
{
    std::vector<unsigned long> points;
    points = _kernel.GetFacetPoints(facets);

    MeshCore::MeshAlgorithm alg(_kernel);
    alg.SetFacetsFlag(facets, MeshCore::MeshFacet::SEGMENT);
    alg.SetPointsFlag(points, MeshCore::MeshPoint::SEGMENT);
}

void MeshObject::updateMesh()
{
    MeshCore::MeshAlgorithm alg(_kernel);
    alg.ResetFacetFlag(MeshCore::MeshFacet::SEGMENT);
    alg.ResetPointFlag(MeshCore::MeshPoint::SEGMENT);
    for (std::vector<Segment>::iterator it = this->_segments.begin();
        it != this->_segments.end(); ++it) {
            std::vector<unsigned long> points;
            points = _kernel.GetFacetPoints(it->getIndices());
            alg.SetFacetsFlag(it->getIndices(), MeshCore::MeshFacet::SEGMENT);
            alg.SetPointsFlag(points, MeshCore::MeshPoint::SEGMENT);
    }
}

std::vector<std::vector<unsigned long> > MeshObject::getComponents() const
{
    std::vector<std::vector<unsigned long> > segments;
    MeshCore::MeshComponents comp(_kernel);
    comp.SearchForComponents(MeshCore::MeshComponents::OverEdge,segments);
    return segments;
}

unsigned long MeshObject::countComponents() const
{
    std::vector<std::vector<unsigned long> > segments;
    MeshCore::MeshComponents comp(_kernel);
    comp.SearchForComponents(MeshCore::MeshComponents::OverEdge,segments);
    return segments.size();
}

void MeshObject::removeComponents(unsigned long count)
{
    std::vector<unsigned long> removeIndices;
    MeshCore::MeshTopoAlgorithm(_kernel).FindComponents(count, removeIndices);
    _kernel.DeleteFacets(removeIndices);
    deletedFacets(removeIndices);
}

void MeshObject::fillupHoles(unsigned long length, int level,
                             MeshCore::AbstractPolygonTriangulator& cTria)
{
    std::list<std::vector<unsigned long> > aFailed;
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    topalg.FillupHoles(length, level, cTria, aFailed);
}

void MeshObject::offset(float fSize)
{
    std::vector<Base::Vector3f> normals = _kernel.CalcVertexNormals();

    unsigned int i = 0;
    // go through all the vertex normals
    for (std::vector<Base::Vector3f>::iterator It= normals.begin();It != normals.end();It++,i++)
        // and move each mesh point in the normal direction
        _kernel.MovePoint(i,It->Normalize() * fSize);
    _kernel.RecalcBoundBox();
}

void MeshObject::offsetSpecial2(float fSize)
{
    Base::Builder3D builder;  
    std::vector<Base::Vector3f> PointNormals= _kernel.CalcVertexNormals();
    std::vector<Base::Vector3f> FaceNormals;
    std::set<unsigned long> fliped;

    MeshCore::MeshFacetIterator it(_kernel);
    for (it.Init(); it.More(); it.Next())
        FaceNormals.push_back(it->GetNormal().Normalize());

    unsigned int i = 0;

    // go through all the vertex normals
    for (std::vector<Base::Vector3f>::iterator It= PointNormals.begin();It != PointNormals.end();It++,i++){
        builder.addSingleLine(_kernel.GetPoint(i),_kernel.GetPoint(i)+It->Normalize() * fSize);
        // and move each mesh point in the normal direction
        _kernel.MovePoint(i,It->Normalize() * fSize);
    }
    _kernel.RecalcBoundBox();

    MeshCore::MeshTopoAlgorithm alg(_kernel);

    for (int l= 0; l<1 ;l++) {
        for ( it.Init(),i=0; it.More(); it.Next(),i++) {
            if (it->IsFlag(MeshCore::MeshFacet::INVALID))
                continue;
            // calculate the angle between them
            float angle = acos((FaceNormals[i] * it->GetNormal()) / (it->GetNormal().Length() * FaceNormals[i].Length()));
            if (angle > 1.6) {
                builder.addSinglePoint(it->GetGravityPoint(),4,1,0,0);
                fliped.insert(it.Position());
            }
        }
        
        // if there no flipped triangels -> stop
        //int f =fliped.size();
        if (fliped.size() == 0)
            break;
      
        for( std::set<unsigned long>::iterator It= fliped.begin();It!=fliped.end();++It)
            alg.CollapseFacet(*It);
        fliped.clear();
    }

    alg.Cleanup();

    // search for intersected facets
    MeshCore::MeshEvalSelfIntersection eval(_kernel);
    std::vector<std::pair<unsigned long, unsigned long> > faces;
    eval.GetIntersections(faces);
    builder.saveToLog();
}

void MeshObject::offsetSpecial(float fSize, float zmax, float zmin)
{
    std::vector<Base::Vector3f> normals = _kernel.CalcVertexNormals();

    unsigned int i = 0;
    // go through all the vertex normals
    for (std::vector<Base::Vector3f>::iterator It= normals.begin();It != normals.end();It++,i++) {
        Base::Vector3f Pnt = _kernel.GetPoint(i);
        if (Pnt.z < zmax && Pnt.z > zmin) {
            Pnt.z = 0;
            _kernel.MovePoint(i,Pnt.Normalize() * fSize);
        }
        else {
            // and move each mesh point in the normal direction
            _kernel.MovePoint(i,It->Normalize() * fSize);
        }
    }
}

void MeshObject::clear(void)
{
    _kernel.Clear();
    this->_segments.clear();
    setTransform(Base::Matrix4D());
}

void MeshObject::transformToEigenSystem()
{
    MeshCore::MeshEigensystem cMeshEval(_kernel);
    cMeshEval.Evaluate();
    this->setTransform(cMeshEval.Transform());
}

void MeshObject::movePoint(unsigned long index, const Base::Vector3d& v)
{
    // v is a vector, hence we must not apply the translation part
    // of the transformation to the vector
    Base::Vector3d vec(v);
    vec.x += _Mtrx[0][3];
    vec.y += _Mtrx[1][3];
    vec.z += _Mtrx[2][3];
    _kernel.MovePoint(index,transformToInside(vec));
}

void MeshObject::setPoint(unsigned long index, const Base::Vector3d& p)
{
    _kernel.SetPoint(index,transformToInside(p));
}

void MeshObject::smooth(int iterations, float d_max)
{
    _kernel.Smooth(iterations, d_max);
}

Base::Vector3d MeshObject::getPointNormal(unsigned long index) const
{
    std::vector<Base::Vector3f> temp = _kernel.CalcVertexNormals();
    Base::Vector3d normal = transformToOutside(temp[index]);

    // the normal is a vector, hence we must not apply the translation part
    // of the transformation to the vector
    normal.x -= _Mtrx[0][3];
    normal.y -= _Mtrx[1][3];
    normal.z -= _Mtrx[2][3];
    normal.Normalize();
    return normal;
}

void MeshObject::crossSections(const std::vector<MeshObject::TPlane>& planes, std::vector<MeshObject::TPolylines> &sections,
                               float fMinEps, bool bConnectPolygons) const
{
    MeshCore::MeshFacetGrid grid(_kernel);
    MeshCore::MeshAlgorithm algo(_kernel);
    for (std::vector<MeshObject::TPlane>::const_iterator it = planes.begin(); it != planes.end(); ++it) {
        MeshObject::TPolylines polylines;
        algo.CutWithPlane(it->first, it->second, grid, polylines, fMinEps, bConnectPolygons);
        sections.push_back(polylines);
    }
}

MeshObject* MeshObject::unite(const MeshObject& mesh) const
{
    MeshCore::MeshKernel result;
    MeshCore::MeshKernel kernel1(this->_kernel);
    kernel1.Transform(this->_Mtrx);
    MeshCore::MeshKernel kernel2(mesh._kernel);
    kernel2.Transform(mesh._Mtrx);
    MeshCore::SetOperations setOp(kernel1, kernel2, result,
                                  MeshCore::SetOperations::Union, Epsilon);
    setOp.Do();
    return new MeshObject(result);
}

MeshObject* MeshObject::intersect(const MeshObject& mesh) const
{
    MeshCore::MeshKernel result;
    MeshCore::MeshKernel kernel1(this->_kernel);
    kernel1.Transform(this->_Mtrx);
    MeshCore::MeshKernel kernel2(mesh._kernel);
    kernel2.Transform(mesh._Mtrx);
    MeshCore::SetOperations setOp(kernel1, kernel2, result,
                                  MeshCore::SetOperations::Intersect, Epsilon);
    setOp.Do();
    return new MeshObject(result);
}

MeshObject* MeshObject::subtract(const MeshObject& mesh) const
{
    MeshCore::MeshKernel result;
    MeshCore::MeshKernel kernel1(this->_kernel);
    kernel1.Transform(this->_Mtrx);
    MeshCore::MeshKernel kernel2(mesh._kernel);
    kernel2.Transform(mesh._Mtrx);
    MeshCore::SetOperations setOp(kernel1, kernel2, result,
                                  MeshCore::SetOperations::Difference, Epsilon);
    setOp.Do();
    return new MeshObject(result);
}

MeshObject* MeshObject::inner(const MeshObject& mesh) const
{
    MeshCore::MeshKernel result;
    MeshCore::MeshKernel kernel1(this->_kernel);
    kernel1.Transform(this->_Mtrx);
    MeshCore::MeshKernel kernel2(mesh._kernel);
    kernel2.Transform(mesh._Mtrx);
    MeshCore::SetOperations setOp(kernel1, kernel2, result,
                                  MeshCore::SetOperations::Inner, Epsilon);
    setOp.Do();
    return new MeshObject(result);
}

MeshObject* MeshObject::outer(const MeshObject& mesh) const
{
    MeshCore::MeshKernel result;
    MeshCore::MeshKernel kernel1(this->_kernel);
    kernel1.Transform(this->_Mtrx);
    MeshCore::MeshKernel kernel2(mesh._kernel);
    kernel2.Transform(mesh._Mtrx);
    MeshCore::SetOperations setOp(kernel1, kernel2, result,
                                  MeshCore::SetOperations::Outer, Epsilon);
    setOp.Do();
    return new MeshObject(result);
}

void MeshObject::refine()
{
    unsigned long cnt = _kernel.CountFacets();
    MeshCore::MeshFacetIterator cF(_kernel);
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    for (unsigned long i=0; i<cnt; i++) {
        cF.Set(i);
        if (!cF->IsDeformed())
            topalg.InsertVertexAndSwapEdge(i, cF->GetGravityPoint(), 0.1f);
    }

    // clear the segments because we don't know how the new
    // topology looks like
    this->_segments.clear();
}

void MeshObject::optimizeTopology(float fMaxAngle)
{
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    if (fMaxAngle > 0.0f)
        topalg.OptimizeTopology(fMaxAngle);
    else
        topalg.OptimizeTopology();

    // clear the segments because we don't know how the new
    // topology looks like
    this->_segments.clear();
}

void MeshObject::optimizeEdges()
{
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    topalg.AdjustEdgesToCurvatureDirection();
}

void MeshObject::splitEdges()
{
    std::vector<std::pair<unsigned long, unsigned long> > adjacentFacet;
    MeshCore::MeshAlgorithm alg(_kernel);
    alg.ResetFacetFlag(MeshCore::MeshFacet::VISIT);
    const MeshCore::MeshFacetArray& rFacets = _kernel.GetFacets();
    for (MeshCore::MeshFacetArray::_TConstIterator pF = rFacets.begin(); pF != rFacets.end(); ++pF) {
        int id=2;
        if (pF->_aulNeighbours[id] != ULONG_MAX) {
            const MeshCore::MeshFacet& rFace = rFacets[pF->_aulNeighbours[id]];
            if (!pF->IsFlag(MeshCore::MeshFacet::VISIT) && !rFace.IsFlag(MeshCore::MeshFacet::VISIT)) {
                pF->SetFlag(MeshCore::MeshFacet::VISIT);
                rFace.SetFlag(MeshCore::MeshFacet::VISIT);
                adjacentFacet.push_back(std::make_pair(pF-rFacets.begin(), pF->_aulNeighbours[id]));
            }
        }
    }

    MeshCore::MeshFacetIterator cIter(_kernel);
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    for (std::vector<std::pair<unsigned long, unsigned long> >::iterator it = adjacentFacet.begin(); it != adjacentFacet.end(); ++it) {
        cIter.Set(it->first);
        Base::Vector3f mid = 0.5f*(cIter->_aclPoints[0]+cIter->_aclPoints[2]);
        topalg.SplitEdge(it->first, it->second, mid);
    }

    // clear the segments because we don't know how the new
    // topology looks like
    this->_segments.clear();
}

void MeshObject::splitEdge(unsigned long facet, unsigned long neighbour, const Base::Vector3f& v)
{
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    topalg.SplitEdge(facet, neighbour, v);
}

void MeshObject::splitFacet(unsigned long facet, const Base::Vector3f& v1, const Base::Vector3f& v2)
{
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    topalg.SplitFacet(facet, v1, v2);
}

void MeshObject::swapEdge(unsigned long facet, unsigned long neighbour)
{
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    topalg.SwapEdge(facet, neighbour);
}

void MeshObject::collapseEdge(unsigned long facet, unsigned long neighbour)
{
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    topalg.CollapseEdge(facet, neighbour);

    std::vector<unsigned long> remFacets;
    remFacets.push_back(facet);
    remFacets.push_back(neighbour);
    deletedFacets(remFacets);
}

void MeshObject::collapseFacet(unsigned long facet)
{
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    topalg.CollapseFacet(facet);

    std::vector<unsigned long> remFacets;
    remFacets.push_back(facet);
    deletedFacets(remFacets);
}

void MeshObject::collapseFacets(const std::vector<unsigned long>& facets)
{
    MeshCore::MeshTopoAlgorithm alg(_kernel);
    for (std::vector<unsigned long>::const_iterator it = facets.begin(); it != facets.end(); ++it) {
        alg.CollapseFacet(*it);
    }

    deletedFacets(facets);
}

void MeshObject::insertVertex(unsigned long facet, const Base::Vector3f& v)
{
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    topalg.InsertVertex(facet, v);
}

void MeshObject::snapVertex(unsigned long facet, const Base::Vector3f& v)
{
    MeshCore::MeshTopoAlgorithm topalg(_kernel);
    topalg.SnapVertex(facet, v);
}

unsigned long MeshObject::countNonUniformOrientedFacets() const
{
    MeshCore::MeshEvalOrientation cMeshEval(_kernel);
    std::vector<unsigned long> inds = cMeshEval.GetIndices();
    return inds.size();
}

void MeshObject::flipNormals()
{
    MeshCore::MeshTopoAlgorithm alg(_kernel);
    alg.FlipNormals();
}

void MeshObject::harmonizeNormals()
{
    MeshCore::MeshTopoAlgorithm alg(_kernel);
    alg.HarmonizeNormals();
}

bool MeshObject::hasNonManifolds() const
{
    MeshCore::MeshEvalTopology cMeshEval(_kernel);
    return !cMeshEval.Evaluate();
}

void MeshObject::removeNonManifolds()
{
    unsigned long count = _kernel.CountFacets();
    MeshCore::MeshEvalTopology cMeshEval(_kernel);
    if (!cMeshEval.Evaluate()) {
        MeshCore::MeshFixTopology cMeshFix(_kernel, cMeshEval.GetFacets());
        cMeshFix.Fixup();
    }

    if (_kernel.CountFacets() < count)
        this->_segments.clear();
}

bool MeshObject::hasSelfIntersections() const
{
    MeshCore::MeshEvalSelfIntersection cMeshEval(_kernel);
    return !cMeshEval.Evaluate();
}

void MeshObject::removeSelfIntersections()
{
    std::vector<std::pair<unsigned long, unsigned long> > selfIntersections;
    MeshCore::MeshEvalSelfIntersection cMeshEval(_kernel);
    cMeshEval.GetIntersections(selfIntersections);

    if (!selfIntersections.empty()) {
        MeshCore::MeshFixSelfIntersection cMeshFix(_kernel, selfIntersections);
        cMeshFix.Fixup();
        this->_segments.clear();
    }
}

void MeshObject::removeSelfIntersections(const std::vector<unsigned long>& indices)
{
    // make sure that the number of indices is even and are in range
    if (indices.size() % 2 != 0)
        return;
    if (std::find_if(indices.begin(), indices.end(), 
        std::bind2nd(std::greater_equal<unsigned long>(), _kernel.CountFacets())) < indices.end())
        return;
    std::vector<std::pair<unsigned long, unsigned long> > selfIntersections;
    std::vector<unsigned long>::const_iterator it;
    for (it = indices.begin(); it != indices.end(); ) {
        unsigned long id1 = *it; ++it;
        unsigned long id2 = *it; ++it;
        selfIntersections.push_back(std::make_pair
            <unsigned long, unsigned long>(id1,id2));
    }

    if (!selfIntersections.empty()) {
        MeshCore::MeshFixSelfIntersection cMeshFix(_kernel, selfIntersections);
        cMeshFix.Fixup();
        this->_segments.clear();
    }
}

void MeshObject::removeFoldsOnSurface()
{
    std::vector<unsigned long> indices;
    MeshCore::MeshEvalFoldsOnSurface s_eval(_kernel);
    MeshCore::MeshEvalFoldOversOnSurface f_eval(_kernel);

    f_eval.Evaluate();
    std::vector<unsigned long> inds  = f_eval.GetIndices();

    s_eval.Evaluate();
    std::vector<unsigned long> inds1 = s_eval.GetIndices();

    // remove duplicates
    inds.insert(inds.end(), inds1.begin(), inds1.end());
    std::sort(inds.begin(), inds.end());
    inds.erase(std::unique(inds.begin(), inds.end()), inds.end());

    if (!inds.empty())
        deleteFacets(inds);

    // do this as additional check after removing folds on closed area
    for (int i=0; i<5; i++) {
        MeshCore::MeshEvalFoldsOnBoundary b_eval(_kernel);
        if (b_eval.Evaluate())
            break;
        inds = b_eval.GetIndices();
        if (!inds.empty())
            deleteFacets(inds);
    }
}

void MeshObject::removeFullBoundaryFacets()
{
    std::vector<unsigned long> facets;
    if (!MeshCore::MeshEvalBorderFacet(_kernel, facets).Evaluate()) {
        deleteFacets(facets);
    }
}

void MeshObject::validateIndices()
{
    unsigned long count = _kernel.CountFacets();

    // for invalid neighbour indices we don't need to check first
    // but start directly with the validation
    MeshCore::MeshFixNeighbourhood fix(_kernel);
    fix.Fixup();

    MeshCore::MeshEvalRangeFacet rf(_kernel);
    if (!rf.Evaluate()) {
        MeshCore::MeshFixRangeFacet fix(_kernel);
        fix.Fixup();
    }

    MeshCore::MeshEvalRangePoint rp(_kernel);
    if (!rp.Evaluate()) {
        MeshCore::MeshFixRangePoint fix(_kernel);
        fix.Fixup();
    }

    MeshCore::MeshEvalCorruptedFacets cf(_kernel);
    if (!cf.Evaluate()) {
        MeshCore::MeshFixCorruptedFacets fix(_kernel);
        fix.Fixup();
    }

    if (_kernel.CountFacets() < count)
        this->_segments.clear();
}

void MeshObject::validateDeformations(float fMaxAngle)
{
    unsigned long count = _kernel.CountFacets();
    MeshCore::MeshFixDeformedFacets eval(_kernel, fMaxAngle);
    eval.Fixup();
    if (_kernel.CountFacets() < count)
        this->_segments.clear();
}

void MeshObject::validateDegenerations()
{
    unsigned long count = _kernel.CountFacets();
    MeshCore::MeshFixDegeneratedFacets eval(_kernel);
    eval.Fixup();
    if (_kernel.CountFacets() < count)
        this->_segments.clear();
}

void MeshObject::removeDuplicatedPoints()
{
    unsigned long count = _kernel.CountFacets();
    MeshCore::MeshFixDuplicatePoints eval(_kernel);
    eval.Fixup();
    if (_kernel.CountFacets() < count)
        this->_segments.clear();
}

void MeshObject::removeDuplicatedFacets()
{
    unsigned long count = _kernel.CountFacets();
    MeshCore::MeshFixDuplicateFacets eval(_kernel);
    eval.Fixup();
    if (_kernel.CountFacets() < count)
        this->_segments.clear();
}

MeshObject* MeshObject::createMeshFromList(Py::List& list)
{
    std::vector<MeshCore::MeshGeomFacet> facets;
    MeshCore::MeshGeomFacet facet;
    int i = 0;
    for (Py::List::iterator it = list.begin(); it != list.end(); ++it) {
        Py::List item(*it);
        for (int j = 0; j < 3; j++) {
            Py::Float value(item[j]);
            facet._aclPoints[i][j] = (float)value;
        }
        if (++i == 3) {
            i = 0;
            facet.CalcNormal();
            facets.push_back(facet);
        }
    }

    std::auto_ptr<MeshObject> mesh(new MeshObject);
    //mesh->addFacets(facets);
    mesh->getKernel() = facets;
    return mesh.release();
}

MeshObject* MeshObject::createSphere(float radius, int sampling)
{
    // load the 'BuildRegularGeoms' module
    Base::PyGILStateLocker lock;
    try {
        Py::Module module(PyImport_ImportModule("BuildRegularGeoms"),true);
        Py::Dict dict = module.getDict();
        Py::Callable call(dict.getItem("Sphere"));
        Py::Tuple args(2);
        args.setItem(0, Py::Float(radius));
        args.setItem(1, Py::Int(sampling));
        Py::List list(call.apply(args));
        return createMeshFromList(list);
    }
    catch (Py::Exception& e) {
        e.clear();
    }

    return 0;
}

MeshObject* MeshObject::createEllipsoid(float radius1, float radius2, int sampling)
{
    // load the 'BuildRegularGeoms' module
    Base::PyGILStateLocker lock;
    try {
        Py::Module module(PyImport_ImportModule("BuildRegularGeoms"),true);
        Py::Dict dict = module.getDict();
        Py::Callable call(dict.getItem("Ellipsoid"));
        Py::Tuple args(3);
        args.setItem(0, Py::Float(radius1));
        args.setItem(1, Py::Float(radius2));
        args.setItem(2, Py::Int(sampling));
        Py::List list(call.apply(args));
        return createMeshFromList(list);
    }
    catch (Py::Exception& e) {
        e.clear();
    }

    return 0;
}

MeshObject* MeshObject::createCylinder(float radius, float length, int closed, float edgelen, int sampling)
{
    // load the 'BuildRegularGeoms' module
    Base::PyGILStateLocker lock;
    try {
        Py::Module module(PyImport_ImportModule("BuildRegularGeoms"),true);
        Py::Dict dict = module.getDict();
        Py::Callable call(dict.getItem("Cylinder"));
        Py::Tuple args(5);
        args.setItem(0, Py::Float(radius));
        args.setItem(1, Py::Float(length));
        args.setItem(2, Py::Int(closed));
        args.setItem(3, Py::Float(edgelen));
        args.setItem(4, Py::Int(sampling));
        Py::List list(call.apply(args));
        return createMeshFromList(list);
    }
    catch (Py::Exception& e) {
        e.clear();
    }

    return 0;
}

MeshObject* MeshObject::createCone(float radius1, float radius2, float len, int closed, float edgelen, int sampling)
{
    // load the 'BuildRegularGeoms' module
    Base::PyGILStateLocker lock;
    try {
        Py::Module module(PyImport_ImportModule("BuildRegularGeoms"),true);
        Py::Dict dict = module.getDict();
        Py::Callable call(dict.getItem("Cone"));
        Py::Tuple args(6);
        args.setItem(0, Py::Float(radius1));
        args.setItem(1, Py::Float(radius2));
        args.setItem(2, Py::Float(len));
        args.setItem(3, Py::Int(closed));
        args.setItem(4, Py::Float(edgelen));
        args.setItem(5, Py::Int(sampling));
        Py::List list(call.apply(args));
        return createMeshFromList(list);
    }
    catch (Py::Exception& e) {
        e.clear();
    }

    return 0;
}

MeshObject* MeshObject::createTorus(float radius1, float radius2, int sampling)
{
    // load the 'BuildRegularGeoms' module
    Base::PyGILStateLocker lock;
    try {
        Py::Module module(PyImport_ImportModule("BuildRegularGeoms"),true);
        Py::Dict dict = module.getDict();
        Py::Callable call(dict.getItem("Toroid"));
        Py::Tuple args(3);
        args.setItem(0, Py::Float(radius1));
        args.setItem(1, Py::Float(radius2));
        args.setItem(2, Py::Int(sampling));
        Py::List list(call.apply(args));
        return createMeshFromList(list);
    }
    catch (Py::Exception& e) {
        e.clear();
    }

    return 0;
}

MeshObject* MeshObject::createCube(float length, float width, float height)
{
    // load the 'BuildRegularGeoms' module
    Base::PyGILStateLocker lock;
    try {
        Py::Module module(PyImport_ImportModule("BuildRegularGeoms"),true);
        Py::Dict dict = module.getDict();
        Py::Callable call(dict.getItem("Cube"));
        Py::Tuple args(3);
        args.setItem(0, Py::Float(length));
        args.setItem(1, Py::Float(width));
        args.setItem(2, Py::Float(height));
        Py::List list(call.apply(args));
        return createMeshFromList(list);
    }
    catch (Py::Exception& e) {
        e.clear();
    }

    return 0;
}

MeshObject* MeshObject::createCube(float length, float width, float height, float edgelen)
{
    // load the 'BuildRegularGeoms' module
    Base::PyGILStateLocker lock;
    try {
        Py::Module module(PyImport_ImportModule("BuildRegularGeoms"),true);
        Py::Dict dict = module.getDict();
        Py::Callable call(dict.getItem("FineCube"));
        Py::Tuple args(4);
        args.setItem(0, Py::Float(length));
        args.setItem(1, Py::Float(width));
        args.setItem(2, Py::Float(height));
        args.setItem(3, Py::Float(edgelen));
        Py::List list(call.apply(args));
        return createMeshFromList(list);
    }
    catch (Py::Exception& e) {
        e.clear();
    }

    return 0;
}

void MeshObject::addSegment(const Segment& s)
{
    addSegment(s.getIndices());
}

void MeshObject::addSegment(const std::vector<unsigned long>& inds)
{
    unsigned long maxIndex = _kernel.CountFacets();
    for (std::vector<unsigned long>::const_iterator it = inds.begin(); it != inds.end(); ++it) {
        if (*it >= maxIndex)
            throw Base::Exception("Index out of range");
    }

    this->_segments.push_back(Segment(this,inds,true));
}

const Segment& MeshObject::getSegment(unsigned long index) const
{
    return this->_segments[index];
}

Segment& MeshObject::getSegment(unsigned long index)
{
    return this->_segments[index];
}

MeshObject* MeshObject::meshFromSegment(const std::vector<unsigned long>& indices) const
{
    MeshCore::MeshFacetArray facets;
    facets.reserve(indices.size());
    const MeshCore::MeshPointArray& kernel_p = _kernel.GetPoints();
    const MeshCore::MeshFacetArray& kernel_f = _kernel.GetFacets();
    for (std::vector<unsigned long>::const_iterator it = indices.begin(); it != indices.end(); ++it) {
        facets.push_back(kernel_f[*it]);
    }

    MeshCore::MeshKernel kernel;
    kernel.Merge(kernel_p, facets);

    return new MeshObject(kernel, _Mtrx);
}

std::vector<Segment> MeshObject::getSegmentsFromType(MeshObject::Type type, const Segment& aSegment, float dev) const
{
    std::vector<Segment> segm;
    unsigned long startFacet, visited;
    if (this->_kernel.CountFacets() == 0)
        return segm;

    // reset VISIT flags
    MeshCore::MeshAlgorithm cAlgo(this->_kernel);
    if (aSegment.isEmpty()) {
        cAlgo.ResetFacetFlag(MeshCore::MeshFacet::VISIT);
    }
    else {
        cAlgo.SetFacetFlag(MeshCore::MeshFacet::VISIT);
        cAlgo.ResetFacetsFlag(aSegment.getIndices(), MeshCore::MeshFacet::VISIT);
    }

    const MeshCore::MeshFacetArray& rFAry = this->_kernel.GetFacets();
    MeshCore::MeshFacetArray::_TConstIterator iTri = rFAry.begin();
    MeshCore::MeshFacetArray::_TConstIterator iBeg = rFAry.begin();
    MeshCore::MeshFacetArray::_TConstIterator iEnd = rFAry.end();

    // start from the first not visited facet
    visited = cAlgo.CountFacetFlag(MeshCore::MeshFacet::VISIT);
    iTri = std::find_if(iTri, iEnd, std::bind2nd(MeshCore::MeshIsNotFlag<MeshCore::MeshFacet>(),
        MeshCore::MeshFacet::VISIT));
    startFacet = iTri - iBeg;

    while (startFacet != ULONG_MAX) {
        // collect all facets of the same geometry
        std::vector<unsigned long> indices;
        indices.push_back(startFacet);
        MeshCore::MeshPlaneVisitor pv(this->_kernel, startFacet, dev, indices);
        visited += this->_kernel.VisitNeighbourFacets(pv, startFacet);

        iTri = std::find_if(iTri, iEnd, std::bind2nd(MeshCore::MeshIsNotFlag<MeshCore::MeshFacet>(),
            MeshCore::MeshFacet::VISIT));
        if (iTri < iEnd)
            startFacet = iTri - iBeg;
        else
            startFacet = ULONG_MAX;
        segm.push_back(Segment(const_cast<MeshObject*>(this), indices, false));
    }

    return segm;
}

// ----------------------------------------------------------------------------

MeshObject::const_point_iterator::const_point_iterator(const MeshObject* mesh, unsigned long index)
  : _mesh(mesh), _p_it(mesh->getKernel())
{
    this->_p_it.Set(index);
    this->_p_it.Transform(_mesh->_Mtrx);
    this->_point.Mesh = const_cast<MeshObject*>(_mesh);
}

MeshObject::const_point_iterator::const_point_iterator(const MeshObject::const_point_iterator& fi)
  : _mesh(fi._mesh), _point(fi._point), _p_it(fi._p_it)
{
}

MeshObject::const_point_iterator::~const_point_iterator()
{
}

MeshObject::const_point_iterator& MeshObject::const_point_iterator::operator=(const MeshObject::const_point_iterator& pi)
{
    this->_mesh  = pi._mesh;
    this->_point = pi._point;
    this->_p_it  = pi._p_it;
    return *this;
}

void MeshObject::const_point_iterator::dereference()
{
    this->_point.x = _p_it->x;
    this->_point.y = _p_it->y;
    this->_point.z = _p_it->z;
    this->_point.Index = _p_it.Position();
}

const MeshPoint& MeshObject::const_point_iterator::operator*()
{
    dereference();
    return this->_point;
}

const MeshPoint* MeshObject::const_point_iterator::operator->()
{
    dereference();
    return &(this->_point);
}

bool MeshObject::const_point_iterator::operator==(const MeshObject::const_point_iterator& pi) const
{
    return (this->_mesh == pi._mesh) && (this->_p_it == pi._p_it);
}

bool MeshObject::const_point_iterator::operator!=(const MeshObject::const_point_iterator& pi) const 
{
    return !operator==(pi);
}

MeshObject::const_point_iterator& MeshObject::const_point_iterator::operator++()
{
    ++(this->_p_it);
    return *this;
}

MeshObject::const_point_iterator& MeshObject::const_point_iterator::operator--()
{
    --(this->_p_it);
    return *this;
}

// ----------------------------------------------------------------------------

MeshObject::const_facet_iterator::const_facet_iterator(const MeshObject* mesh, unsigned long index)
  : _mesh(mesh), _f_it(mesh->getKernel())
{
    this->_f_it.Set(index);
    this->_f_it.Transform(_mesh->_Mtrx);
    this->_facet.Mesh = const_cast<MeshObject*>(_mesh);
}

MeshObject::const_facet_iterator::const_facet_iterator(const MeshObject::const_facet_iterator& fi)
  : _mesh(fi._mesh), _facet(fi._facet), _f_it(fi._f_it)
{
}

MeshObject::const_facet_iterator::~const_facet_iterator()
{
}

MeshObject::const_facet_iterator& MeshObject::const_facet_iterator::operator=(const MeshObject::const_facet_iterator& fi)
{
    this->_mesh  = fi._mesh;
    this->_facet = fi._facet;
    this->_f_it  = fi._f_it;
    return *this;
}

void MeshObject::const_facet_iterator::dereference()
{
    this->_facet.MeshCore::MeshGeomFacet::operator = (*_f_it);
    this->_facet.Index = _f_it.Position();
    const MeshCore::MeshFacet& face = _f_it.GetReference();
    for (int i=0; i<3;i++) {
        this->_facet.PIndex[i] = face._aulPoints[i];
        this->_facet.NIndex[i] = face._aulNeighbours[i];
    }
}

Facet& MeshObject::const_facet_iterator::operator*()
{
    dereference();
    return this->_facet;
}

Facet* MeshObject::const_facet_iterator::operator->()
{
    dereference();
    return &(this->_facet);
}

bool MeshObject::const_facet_iterator::operator==(const MeshObject::const_facet_iterator& fi) const
{
    return (this->_mesh == fi._mesh) && (this->_f_it == fi._f_it);
}

bool MeshObject::const_facet_iterator::operator!=(const MeshObject::const_facet_iterator& fi) const 
{
    return !operator==(fi);
}

MeshObject::const_facet_iterator& MeshObject::const_facet_iterator::operator++()
{
    ++(this->_f_it);
    return *this;
}

MeshObject::const_facet_iterator& MeshObject::const_facet_iterator::operator--()
{
    --(this->_f_it);
    return *this;
}