[occt.git] / src / BRepCheck / BRepCheck_Shell.cxx

// Created on: 1995-12-12
// Created by: Jacques GOUSSARD
// Copyright (c) 1995-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.


#include <BRep_Builder.hxx>
#include <BRep_Tool.hxx>
#include <BRepCheck.hxx>
#include <BRepCheck_ListIteratorOfListOfStatus.hxx>
#include <BRepCheck_ListOfStatus.hxx>
#include <BRepCheck_Shell.hxx>
#include <Standard_Type.hxx>
#include <TopExp.hxx>
#include <TopExp_Explorer.hxx>
#include <TopoDS.hxx>
#include <TopoDS_Edge.hxx>
#include <TopoDS_Face.hxx>
#include <TopoDS_Shape.hxx>
#include <TopoDS_Shell.hxx>
#include <TopTools_DataMapIteratorOfDataMapOfShapeInteger.hxx>
#include <TopTools_DataMapOfShapeInteger.hxx>
#include <TopTools_IndexedDataMapOfShapeListOfShape.hxx>
#include <TopTools_ListIteratorOfListOfShape.hxx>
#include <TopTools_ListOfShape.hxx>
#include <TopTools_MapIteratorOfMapOfShape.hxx>
#include <TopTools_MapOfShape.hxx>

IMPLEMENT_STANDARD_RTTIEXT(BRepCheck_Shell,BRepCheck_Result)

//=======================================================================
//function : Propagate
//purpose  : 
//=======================================================================
static void Propagate(const TopTools_IndexedDataMapOfShapeListOfShape& mapEF,
                      const TopoDS_Shape& theFace,
                      TopTools_IndexedMapOfShape& theMapF)
{
  // Base for the traverse procedure.
  theMapF.Add(theFace);

  // Perform well-known width-first traverse.
  for (Standard_Integer anIdx = 1; anIdx <= theMapF.Extent(); ++anIdx)
  {
    const TopoDS_Shape& aFace = theMapF(anIdx);
    for (TopExp_Explorer ex(aFace, TopAbs_EDGE); ex.More(); ex.Next())
    {
      const TopoDS_Edge& edg = TopoDS::Edge(ex.Current());

      // Test if the edge is in the map (only oriented edges are present).
      const TopTools_ListOfShape* aList = mapEF.Seek(edg);

      if ( aList == NULL )
        continue;

      for (TopTools_ListIteratorOfListOfShape itl(*aList); itl.More(); itl.Next())
      {
        // This code assumes that shape is added to an end of the map.
        // The idea is simple: existing objects will not be added, new objects
        // will be added to an end.
        theMapF.Add(itl.Value());
      }
    }
  }
}

//=======================================================================
//function : BRepCheck_Trace
//purpose  : 
//=======================================================================
Standard_EXPORT Standard_Integer BRepCheck_Trace(const Standard_Integer phase) {
  static int BRC_Trace = 0;
  if (phase < 0) BRC_Trace =0;
  else if (phase > 0) BRC_Trace=phase;
  return BRC_Trace;
}

void PrintShape(const TopoDS_Shape& theShape, const Standard_Integer upper) {
  if (!theShape.IsNull()) {
    Standard_Integer code = theShape.HashCode(upper);
    std::cout << TopAbs::ShapeTypeToString (theShape.ShapeType()) << " : " << code
       << " " << TopAbs::ShapeOrientationToString(theShape.Orientation()) << std::endl;
  }
}
    
//=======================================================================
//function : IsOriented
//purpose  : 
//=======================================================================
inline Standard_Boolean IsOriented(const TopoDS_Shape& S)
{
  return (S.Orientation() == TopAbs_FORWARD ||
	  S.Orientation() == TopAbs_REVERSED);
}


//=======================================================================
//function : BRepCheck_Shell
//purpose  : 
//=======================================================================

BRepCheck_Shell::BRepCheck_Shell(const TopoDS_Shell& S)
{
  Init(S);
}


//=======================================================================
//function : Minimum
//purpose  : 
//=======================================================================
void BRepCheck_Shell::Minimum()
{
  myCdone = Standard_False;
  myOdone = Standard_False;

  if (!myMin)
  {
    BRepCheck_ListOfStatus thelist;
    myMap.Bind(myShape, thelist);
    BRepCheck_ListOfStatus& lst = myMap(myShape);

    // it is checked if the shell is "connected"
    TopExp_Explorer exp(myShape,TopAbs_FACE);
    Standard_Integer nbface = 0;
    myMapEF.Clear();
    for (; exp.More(); exp.Next())
    {
      nbface++;
      TopExp_Explorer expe;
      for (expe.Init(exp.Current(),TopAbs_EDGE);
                        expe.More(); expe.Next())
      {
        const TopoDS_Shape& edg = expe.Current();
        Standard_Integer index = myMapEF.FindIndex(edg);
        if (index == 0)
        {
          TopTools_ListOfShape thelist1;
          index = myMapEF.Add(edg, thelist1);
        }

        myMapEF(index).Append(exp.Current());
      }
    }//for (; exp.More(); exp.Next())

    if (nbface == 0)
    {
      BRepCheck::Add(lst,BRepCheck_EmptyShell);
    }
    else if (nbface >= 2)
    {
      TopTools_IndexedMapOfShape mapF;
      exp.ReInit();

      Propagate(myMapEF,exp.Current(),mapF);

      if (mapF.Extent() != nbface)
      {
        BRepCheck::Add(lst,BRepCheck_NotConnected);
      }
    }//else if (nbface >= 2)

    if (lst.IsEmpty())
    {
      lst.Append(BRepCheck_NoError);
    }
    
    myMapEF.Clear();
    myMin = Standard_True;
  }
}

//=======================================================================
//function : InContext
//purpose  : 
//=======================================================================

void BRepCheck_Shell::InContext(const TopoDS_Shape& S)
{

  if (myMap.IsBound(S)) {
    return;
  }
  BRepCheck_ListOfStatus thelist;
  myMap.Bind(S, thelist);

  BRepCheck_ListOfStatus& lst = myMap(S);

//  for (TopExp_Explorer exp(S,TopAbs_SHELL); exp.More(); exp.Next()) {
  TopExp_Explorer exp(S,TopAbs_SHELL) ;
  for ( ; exp.More(); exp.Next()) {
    if (exp.Current().IsSame(myShape)) {
      break;
    }
  }
  if (!exp.More()) {
    BRepCheck::Add(lst,BRepCheck_SubshapeNotInShape);
    return;
  }

  TopAbs_ShapeEnum styp = S.ShapeType();
  switch (styp) {

  case TopAbs_SOLID:
    {
      BRepCheck_Status fst = Closed();
      if ((fst == BRepCheck_NotClosed && S.Closed()) ||
	  (fst != BRepCheck_NoError)) {
	BRepCheck::Add(lst,fst);
      }
      else if (!IsUnorientable()) {
	fst = Orientation();
	BRepCheck::Add(lst,fst);
      }
    }
    break;

  default:
    break;
  }


  if (lst.IsEmpty()) {
    lst.Append(BRepCheck_NoError);
  }
}


//=======================================================================
//function : Blind
//purpose  : 
//=======================================================================

void BRepCheck_Shell::Blind()
{
  if (!myBlind) {
    // nothing more than in the minimum
    myBlind = Standard_True;
  }
}


//=======================================================================
//function : Closed
//purpose  : 
//=======================================================================
BRepCheck_Status BRepCheck_Shell::Closed(const Standard_Boolean Update)
{
  if (myCdone)
  {
    if (Update)
    {
      BRepCheck::Add(myMap(myShape), myCstat);
    }

    return myCstat;
  }

  myCdone = Standard_True; // it will be done...

  BRepCheck_ListIteratorOfListOfStatus itl(myMap(myShape));
  if (itl.Value() != BRepCheck_NoError)
  {
    myCstat = itl.Value();
    return myCstat; // already saved
  }

  myCstat = BRepCheck_NoError;
  //
  Standard_Integer index, aNbF;
  TopExp_Explorer exp, ede;
  TopTools_IndexedMapOfShape mapS;
  TopTools_MapOfShape aMEToAvoid;
  myMapEF.Clear();
  

  // Checks if the oriented faces of the shell give a "closed" shell,
  // i-e if each oriented edge on oriented faces is found 2 times.
  //
  //modified by NIZNHY-PKV Mon Jun  4 13:59:21 2007f
  exp.Init(myShape,TopAbs_FACE);
  for (; exp.More(); exp.Next())
  {
    const TopoDS_Shape& aF=exp.Current();
    if (IsOriented(aF))
    {
      ede.Init(exp.Current(),TopAbs_EDGE);
      for (; ede.More(); ede.Next())
      {
        const TopoDS_Shape& aE=ede.Current();
        if (!IsOriented(aE))
        {
          aMEToAvoid.Add(aE);
        }
      }
    }
  }
  //modified by NIZNHY-PKV Mon Jun  4 13:59:23 2007t
  //
  exp.Init(myShape,TopAbs_FACE);
  for (; exp.More(); exp.Next())
  {
    const TopoDS_Shape& aF=exp.Current();
    if (IsOriented(aF))
    {
      if (!mapS.Add(aF))
      {
        myCstat = BRepCheck_RedundantFace;
        
        if (Update)
        {
          BRepCheck::Add(myMap(myShape),myCstat);
        }

        return myCstat;
      }

      //
      ede.Init(exp.Current(),TopAbs_EDGE);
      for (; ede.More(); ede.Next())
      {
        const TopoDS_Shape& aE=ede.Current();
        //modified by NIZNHY-PKV Mon Jun  4 14:07:57 2007f
        //if (IsOriented(aE)) {
        if (!aMEToAvoid.Contains(aE))
        {
          //modified by NIZNHY-PKV Mon Jun  4 14:08:01 2007
          index = myMapEF.FindIndex(aE);
          
          if (!index)
          {
            TopTools_ListOfShape thelist;
            index = myMapEF.Add(aE, thelist);
          }

          myMapEF(index).Append(aF);
        }
      }
    }
  }

  //
  myNbori = mapS.Extent();
  if (myNbori >= 2)
  {
    mapS.Clear();
    // Search for the first oriented face
    TopoDS_Shape aF;
    exp.Init(myShape, TopAbs_FACE);
    for (;exp.More(); exp.Next())
    {
      aF=exp.Current();
      if (IsOriented(aF))
      {
        break;
      }
    }

    Propagate(myMapEF, aF, mapS);
  }
  //

  //
  aNbF=mapS.Extent();
  if (myNbori != aNbF)
  {
    myCstat = BRepCheck_NotConnected;
    if (Update)
    {
      BRepCheck::Add(myMap(myShape),myCstat);
    }
    return myCstat;
  }
  //
  //
  Standard_Integer i, Nbedges, nboc, nbSet;
  //
  Nbedges = myMapEF.Extent();
  for (i = 1; i<=Nbedges; ++i)
  {
    nboc = myMapEF(i).Extent();
    if (nboc == 0 || nboc >= 3)
    {
      TopTools_ListOfShape theSet;
      nbSet=NbConnectedSet(theSet);
      // If there is more than one closed cavity the shell is considered invalid
      // this corresponds to the criteria of a solid (not those of a shell)
      if (nbSet>1)
      {
        myCstat = BRepCheck_InvalidMultiConnexity;
        if (Update)
        {
          BRepCheck::Add(myMap(myShape),myCstat);
        }

        return myCstat;
      }
    }
    else if (nboc == 1)
    {
      if (!BRep_Tool::Degenerated(TopoDS::Edge(myMapEF.FindKey(i))))
      {
        myCstat=BRepCheck_NotClosed;
        if (Update)
        {
          BRepCheck::Add(myMap(myShape),myCstat);
        }

        return myCstat;
      }
    }
  }
  
  if (Update) {
    BRepCheck::Add(myMap(myShape),myCstat);
  }
  return myCstat;
}


//=======================================================================
//function : Orientation
//purpose  : 
//=======================================================================

BRepCheck_Status BRepCheck_Shell::Orientation(const Standard_Boolean Update)
{
  if (myOdone) {
    if (Update) {
      BRepCheck::Add(myMap(myShape), myOstat);
    }
    return myOstat;
  }
  myOdone = Standard_True;

  myOstat = Closed();
  if (myOstat != BRepCheck_NotClosed && myOstat != BRepCheck_NoError) {
    if (Update) {
      BRepCheck::Add(myMap(myShape), myOstat);
    }
    return myOstat;
  }

  myOstat = BRepCheck_NoError;


// First the orientation of each face in relation to the shell is found.
// It is used to check BRepCheck_RedundantFace

  TopTools_DataMapOfShapeInteger MapOfShapeOrientation;
  TopExp_Explorer exp,ede;

  for (exp.Init(myShape,TopAbs_FACE); exp.More(); exp.Next()) {
    if (!MapOfShapeOrientation.Bind(exp.Current(), (Standard_Integer)(exp.Current().Orientation()))) {
      myOstat = BRepCheck_RedundantFace;
      if (Update) {
	BRepCheck::Add(myMap(myShape), myOstat);
      }
      else {
	return myOstat;
      }
    }
  }

#ifdef OCCT_DEBUG
  if (BRepCheck_Trace(0) > 1) {
    TopTools_DataMapIteratorOfDataMapOfShapeInteger itt(MapOfShapeOrientation);
    Standard_Integer upper = MapOfShapeOrientation.NbBuckets();
    cout << "La map shape Orientation :" << endl;
    for (; itt.More(); itt.Next()) {
      PrintShape(itt.Key(), upper);
    }
    cout << endl;
  }
#endif


// Then the orientation of faces by their connectivity is checked
// BRepCheck_BadOrientationOfSubshape and 
//         BRepCheck_SubshapeNotInShape are checked;

  Standard_Integer Nbedges = myMapEF.Extent();
  TopoDS_Face Fref;
  TopAbs_Orientation orf;

  for (Standard_Integer i = 1; i<= Nbedges; i++) {

    const TopoDS_Edge& edg = TopoDS::Edge(myMapEF.FindKey(i));
    if (BRep_Tool::Degenerated(edg)) continue;
    TopTools_ListOfShape& lface = myMapEF(i);
    TopTools_ListIteratorOfListOfShape lite(lface);

    if (lface.Extent() <= 2)
      {
	lite.Initialize(lface);
	Fref = TopoDS::Face(lite.Value());
	
	if (!MapOfShapeOrientation.IsBound(Fref)) {
	  myOstat = BRepCheck_SubshapeNotInShape;
	  if (Update) {
	    BRepCheck::Add(myMap(myShape), myOstat);
	    }
	  // quit because no workaround for the incoherence is possible
	  return myOstat;
	}
	lite.Next();
	
	if (lite.More()) { // Edge of connectivity
	  //JR/Hp :
	  Standard_Integer iorf = MapOfShapeOrientation.Find(Fref);
	  orf = (TopAbs_Orientation) iorf;
	  //orf = (TopAbs_Orientation)MapOfShapeOrientation.Find(Fref);
	  Fref.Orientation(orf);
	  
	  // edge is examined
	  if (!lite.Value().IsSame(Fref)) { // edge non "closed"
	    for (ede.Init(Fref,TopAbs_EDGE); ede.More(); ede.Next()) {
	      if (ede.Current().IsSame(edg)) {
		break;
	      }
	    }
	    TopAbs_Orientation orient = ede.Current().Orientation();
	    TopoDS_Face Fcur= TopoDS::Face(lite.Value());
	    
	    if (!MapOfShapeOrientation.IsBound(Fcur)) {
	      myOstat = BRepCheck_SubshapeNotInShape;
	      if (Update) {
		BRepCheck::Add(myMap(myShape), myOstat);
		}
	      // quit because no workaround for the incoherence is possible
	      return myOstat;
	    }
	    
	    //JR/Hp :
	    Standard_Integer anOriFCur = MapOfShapeOrientation.Find(Fcur) ;
	    orf = (TopAbs_Orientation)anOriFCur;
	    //	orf = (TopAbs_Orientation)MapOfShapeOrientation.Find(Fcur);
	    Fcur.Orientation(orf);
	    
	    for (ede.Init(Fcur, TopAbs_EDGE); ede.More(); ede.Next()) {
	      if (ede.Current().IsSame(edg)) {
		break;
	      }
	    }
	    if (ede.Current().Orientation() == orient) {
	      // The loop is continued on the edges as many times 
	      // as the same edge is present in the wire

	      // modified by NIZHNY-MKK  Tue Sep 30 11:11:42 2003
	      Standard_Boolean bfound = Standard_False;
	      ede.Next();
	      for (; ede.More(); ede.Next()) {
		if (ede.Current().IsSame(edg)) {
		  // modified by NIZHNY-MKK  Tue Sep 30 11:12:03 2003
		  bfound = Standard_True;
		  break;
		}
	      }
	      // 	      if (ede.Current().Orientation() == orient) {
	      // modified by NIZHNY-MKK  Thu Oct  2 17:56:47 2003
	      if (!bfound || (ede.Current().Orientation() == orient)) {
		myOstat = BRepCheck_BadOrientationOfSubshape;
		if (Update) {
		  BRepCheck::Add(myMap(myShape), myOstat);
		    break;
		  }
		return myOstat;
	      }
	    }
	  }
	}
      }
    else //more than two faces
      {
	Standard_Integer numF = 0, numR = 0;
	TopTools_MapOfShape Fmap;

	for (lite.Initialize(lface); lite.More(); lite.Next())
	  {
	    TopoDS_Face Fcur= TopoDS::Face(lite.Value());
	    if (!MapOfShapeOrientation.IsBound(Fcur))
	      {
		myOstat = BRepCheck_SubshapeNotInShape;
		if (Update)
		  BRepCheck::Add(myMap(myShape), myOstat);
	      // quit because no workaround for the incoherence is possible
		return myOstat;
	      }

	    Standard_Integer iorf = MapOfShapeOrientation.Find(Fcur);
	    orf = (TopAbs_Orientation) iorf;
	    //orf = (TopAbs_Orientation)MapOfShapeOrientation.Find(Fcur);
	    Fcur.Orientation(orf);

	    for (ede.Init(Fcur,TopAbs_EDGE); ede.More(); ede.Next())
	      if (ede.Current().IsSame(edg))
		break;
	    if (Fmap.Contains(Fcur)) //edge is "closed" on Fcur, we meet Fcur twice
	      {
		ede.Next();
		for (; ede.More(); ede.Next())
		  if (ede.Current().IsSame(edg))
		    break;
	      }
	    TopAbs_Orientation orient = ede.Current().Orientation();
	    if (orient == TopAbs_FORWARD)
	      numF++;
	    else
	      numR++;

	    Fmap.Add(Fcur);
	  }

	if (numF != numR)
	  {
	    myOstat = BRepCheck_BadOrientationOfSubshape;
	    if (Update)
	      {
		BRepCheck::Add(myMap(myShape), myOstat);
		break;
	      }
	    return myOstat;
	  }
      }
  }

// If at least one incorrectly oriented face has been found, it is checked if the shell can be oriented. 
//          i.e. : if by modification of the orientation of a face it is possible to find 
//          a coherent orientation. (it is not possible on a Moebius band)
//          BRepCheck_UnorientableShape is checked

  if (myOstat == BRepCheck_BadOrientationOfSubshape) {
    if (!Fref.IsNull()) {
      if (Nbedges > 0) {
	TopTools_MapOfShape alre;
	TopTools_ListOfShape voisin;
	voisin.Append(Fref);
	alre.Clear();
	while (!voisin.IsEmpty()) {
	  Fref=TopoDS::Face(voisin.First());
	  voisin.RemoveFirst();
	  if (!MapOfShapeOrientation.IsBound(Fref)) {
	    myOstat = BRepCheck_SubshapeNotInShape;
	    if (Update) {
	      BRepCheck::Add(myMap(myShape), myOstat);
	    }
	    // quit because no workaround for the incoherence is possible
	    return myOstat;
	  }
//JR/Hp :
          Standard_Integer iorf = MapOfShapeOrientation.Find(Fref) ;
	  orf = (TopAbs_Orientation) iorf ;
//	  orf = (TopAbs_Orientation)MapOfShapeOrientation.Find(Fref);
	  Fref.Orientation(orf);

#ifdef OCCT_DEBUG
  if (BRepCheck_Trace(0) > 3) {
    cout << "Fref : " ;
    PrintShape(Fref, MapOfShapeOrientation.NbBuckets());
  }
#endif

	  TopExp_Explorer edFcur;
	  alre.Add(Fref);

	  for (ede.Init(Fref,TopAbs_EDGE); ede.More(); ede.Next()) {
	    const TopoDS_Edge& edg = TopoDS::Edge(ede.Current());
	    TopAbs_Orientation orient = edg.Orientation();
	    TopTools_ListOfShape& lface = myMapEF.ChangeFromKey(edg);
	    TopTools_ListIteratorOfListOfShape lite(lface);
	  
	    TopoDS_Face Fcur= TopoDS::Face(lite.Value());
	    if (Fcur.IsSame(Fref)) {
	      lite.Next();
	      if (lite.More()) {
		Fcur=TopoDS::Face(lite.Value());
	      }
	      else {
		// from the free border one goes to the next edge
		continue;
	      }
	    }

	    if (!MapOfShapeOrientation.IsBound(Fcur)) {
	      myOstat = BRepCheck_SubshapeNotInShape;
	      if (Update) {
		BRepCheck::Add(myMap(myShape), myOstat);
	      }
	      // quit because no workaround for the incoherence is possible
	      return myOstat;
	    }

//JR/Hp :
            Standard_Integer anOriFCur = MapOfShapeOrientation.Find(Fcur) ;
	    orf = (TopAbs_Orientation)anOriFCur;
//	    orf = (TopAbs_Orientation)MapOfShapeOrientation.Find(Fcur);
	    Fcur.Orientation(orf);

#ifdef OCCT_DEBUG
  if (BRepCheck_Trace(0) > 3) {
    cout << "    Fcur : " ;
    PrintShape(Fcur, MapOfShapeOrientation.NbBuckets());
  }
#endif
	    for (edFcur.Init(Fcur, TopAbs_EDGE); edFcur.More(); edFcur.Next()) {
	      if (edFcur.Current().IsSame(edg)) {
		break;
	      }
	    }
	    if (edFcur.Current().Orientation() == orient) {
	      if (alre.Contains(Fcur)) {
		// It is necessary to return a face that has been already examined or returned
		// if one gets nowhere, the shell cannot be oriented.
		myOstat = BRepCheck_UnorientableShape;
		if (Update) {
		  BRepCheck::Add(myMap(myShape), myOstat);
		}
		// quit, otherwise there is a risk of taking too much time.
#ifdef OCCT_DEBUG
  if (BRepCheck_Trace(0) > 3) {
    orf = (TopAbs_Orientation)MapOfShapeOrientation.Find(Fcur);
    Fcur.Orientation(orf);
    cout << "    Error : this face has been already examined " << endl;
    cout << "    Imposible to return it ";
    PrintShape(Fcur, MapOfShapeOrientation.NbBuckets());
  }
#endif
		return myOstat;
	      }
	      orf = TopAbs::Reverse(orf);
	      MapOfShapeOrientation(Fcur)=orf;


#ifdef OCCT_DEBUG
  if (BRepCheck_Trace(0) > 3) {
    orf = (TopAbs_Orientation)MapOfShapeOrientation.Find(Fcur);
    Fcur.Orientation(orf);
    cout << "    Resulting Fcur is returned : " ;
    PrintShape(Fcur, MapOfShapeOrientation.NbBuckets());
  }
#endif

	    }
	    if (alre.Add(Fcur)) {
	      voisin.Append(Fcur);
	    }
	  }
	}
      }
    }
  }

  if (Update) {
    BRepCheck::Add(myMap(myShape), myOstat);
  }
  return myOstat;
}

//=======================================================================
//function : SetUnorientable
//purpose  : 
//=======================================================================

void BRepCheck_Shell::SetUnorientable()
{
  BRepCheck::Add(myMap(myShape),BRepCheck_UnorientableShape);
}


//=======================================================================
//function : IsUnorientable
//purpose  : 
//=======================================================================

Standard_Boolean BRepCheck_Shell::IsUnorientable() const
{
  if (myOdone) {
    return (myOstat != BRepCheck_NoError);
  }
  for (BRepCheck_ListIteratorOfListOfStatus itl(myMap(myShape));
       itl.More();
       itl.Next()) {
    if (itl.Value() == BRepCheck_UnorientableShape) {
      return Standard_True;
    }
  }
  return Standard_False;
}

//=======================================================================
//function : NbConnectedSet
//purpose  : 
//=======================================================================

Standard_Integer BRepCheck_Shell::NbConnectedSet(TopTools_ListOfShape& theSets)
{
  // The connections are found 
  TopTools_IndexedDataMapOfShapeListOfShape parents;
  TopExp::MapShapesAndAncestors(myShape, TopAbs_EDGE, TopAbs_FACE, parents);
  // All faces are taken
  TopTools_MapOfShape theFaces;
  TopExp_Explorer exsh(myShape, TopAbs_FACE);
  for (; exsh.More(); exsh.Next()) theFaces.Add(exsh.Current());
  // The edges that are not oriented or have more than 2 connections are missing
  Standard_Integer iCur;
  TopTools_MapOfShape theMultiEd;
  TopTools_MapOfShape theUnOriEd;
  for (iCur=1; iCur<=parents.Extent(); iCur++) {
    const TopoDS_Edge& Ed = TopoDS::Edge(parents.FindKey(iCur));
    if (parents(iCur).Extent()> 2) theMultiEd.Add(Ed);
    if (Ed.Orientation()!=TopAbs_REVERSED &&
	Ed.Orientation()!=TopAbs_FORWARD) theUnOriEd.Add(Ed);
  }
  // Starting from multiconnected edges propagation by simple connections
  TopTools_ListIteratorOfListOfShape lconx1, lconx2;
  TopTools_MapIteratorOfMapOfShape itmsh(theMultiEd);
  TopoDS_Shell CurShell;
  TopoDS_Shape adFac;
  TopTools_ListOfShape lesCur;
  BRep_Builder BRB;
  Standard_Boolean newCur=Standard_True;
  BRB.MakeShell(CurShell);
  for (; itmsh.More(); itmsh.Next()) {
    const TopoDS_Shape& Ed = itmsh.Key();
    if (!theUnOriEd.Contains(Ed)) {
      for (lconx1.Initialize(parents.FindFromKey(Ed)); lconx1.More(); lconx1.Next()) {
	if (theFaces.Contains(lconx1.Value())) {
	  adFac=lconx1.Value();
	  BRB.Add(CurShell, adFac);
	  theFaces.Remove(adFac);
	  newCur=Standard_False;
	  if (theFaces.IsEmpty()) break;
	  lesCur.Append(adFac);
	  while (!lesCur.IsEmpty()) {
	    adFac=lesCur.First();
	    lesCur.RemoveFirst();
	    for (exsh.Init(adFac, TopAbs_EDGE); exsh.More(); exsh.Next()) {
	      const TopoDS_Shape& ced = exsh.Current();
	      if (!theMultiEd.Contains(ced)) {
		for (lconx2.Initialize(parents.FindFromKey(ced)); lconx2.More(); lconx2.Next()) {
		  if (theFaces.Contains(lconx2.Value())) {
		    adFac=lconx2.Value();
		    BRB.Add(CurShell, adFac);
		    theFaces.Remove(adFac);
		    newCur=Standard_False;
		    if (theFaces.IsEmpty()) break;
		    lesCur.Append(adFac);
		  }
		}
	      }
	      if (theFaces.IsEmpty()) break;
	    }
	  }
	  if (!newCur) {
            CurShell.Closed (BRep_Tool::IsClosed (CurShell));
            theSets.Append(CurShell);
            CurShell.Nullify();
            newCur=Standard_True;
            BRB.MakeShell(CurShell);
	  }
	}
	if (theFaces.IsEmpty()) break;
      }
    }
    if (theFaces.IsEmpty()) break;
  }
  return theSets.Extent();
}