0026265: Incorrect result of 2d offset

Additional treatment has been added as the last step of the offset procedure to remove wrong parts (loops) from the result.

src/BRepFill/BRepFill_OffsetWire.cxx

@@ -101,6 +101,31 @@
 #include <TopTools_MapOfShape.hxx>
 #include <TopTools_SequenceOfShape.hxx>
 
+#include <TColStd_IndexedMapOfReal.hxx>
+#include <NCollection_DataMap.hxx>
+#include <NCollection_QuickSort.hxx>
+#include <BRepTopAdaptor_FClass2d.hxx>
+#include <BRepBuilderAPI_MakeFace.hxx>
+#include <Geom2dAPI_InterCurveCurve.hxx>
+#include <BRepTools_ReShape.hxx>
+#include <BRepBuilderAPI_MakeVertex.hxx>
+#include <Poly_MakeLoops.hxx>
+#include <BRepBuilderAPI_MakeEdge.hxx>
+#include <BRepBuilderAPI_MakeWire.hxx>
+#include <GeomLib.hxx>
+#include <BRepFill.hxx>
+#include <ShapeExtend_WireData.hxx>
+#include <ShapeFix_Wire.hxx>
+#include <ShapeAnalysis_WireOrder.hxx>
+#include <ShapeAnalysis_Wire.hxx>
+#include <NCollection_UBTreeFiller.hxx>
+#include <BndLib_Add2dCurve.hxx>
+#include <Bnd_Box2d.hxx>
+#include <NCollection_DoubleMap.hxx>
+#include <TColStd_ListOfInteger.hxx>
+#include <NCollection_UBTree.hxx>
+#include <NCollection_Array1.hxx>
+
 #include <stdio.h>
 #ifdef OCCT_DEBUG
 //#define DRAW
@@ -120,6 +145,305 @@ static Standard_Integer NbBISSEC    = 0;
 #endif
 #endif
 
+//! This struct defines link (i.e. edge) with its vertices and first derivative of pcurves on the both tails of the edge  
+struct TopoLink 
+{
+  TopoDS_Vertex myFV;
+  TopoDS_Vertex myLV;
+  gp_Dir2d myD1L;
+  gp_Dir2d myD1F;
+};
+
+typedef NCollection_UBTree <Standard_Integer, Bnd_Box2d> BRepFill_BndBoxTree;
+
+
+//!   This class is used to select overlapping 2d boxes, stored in NCollection::UBTree
+class BRepFill_BndBoxTreeSelector : public BRepFill_BndBoxTree::Selector
+{
+public:
+  //!   Defines "edge in intersection" info
+  struct EdgeParam
+  {
+    TopoDS_Edge myEdgeInt; //edge in intersection
+    double myParamInt; // parameter on the edge
+    TopoDS_Vertex myIntVertex; // Vertex of the intersection point
+  };
+
+public:
+  BRepFill_BndBoxTreeSelector( TopTools_SequenceOfShape& theSeqOfEdges,
+                               const TopoDS_Face& theWFace) 
+    : BRepFill_BndBoxTreeSelector::Selector(), mySeqOfEdges (theSeqOfEdges), myWFace (theWFace) {}
+
+  BRepFill_BndBoxTreeSelector(const BRepFill_BndBoxTreeSelector& );
+  BRepFill_BndBoxTreeSelector& operator=(const BRepFill_BndBoxTreeSelector& );
+
+  Standard_Boolean Reject (const Bnd_Box2d& theBox) const
+  {
+    return (myCBox.IsOut (theBox));
+  }
+
+  Standard_Boolean Accept (const Standard_Integer& theObj)
+  {
+    //intersection between bounding boxes was found, try to find intersection of edges 
+    NCollection_List<NCollection_Array1<int>>::Iterator It(myEdgeIndexes);
+    for (; It.More(); It.Next())
+    {
+      if (It.Value()(1) == myCInd && It.Value()(2) == theObj) //skip already computed intersections
+        return Standard_False;
+    }
+    if (theObj != myCInd) //try to find intersection between two given edges
+    {
+      TopoDS_Edge E1 = TopoDS::Edge(mySeqOfEdges(theObj));
+      TopoDS_Edge E2 = TopoDS::Edge(mySeqOfEdges(myCInd));
+      {
+        Handle_Geom2d_Curve aCur1;
+        double f, l;
+        aCur1 = BRep_Tool::CurveOnSurface(E1, myWFace, f, l ); 
+
+        Handle_Geom2d_Curve aCur2;
+        double f2, l2;
+        aCur2 = BRep_Tool::CurveOnSurface(E2, myWFace, f2, l2 ); 
+
+        double IntPrec = Precision::Confusion();
+        Geom2dAPI_InterCurveCurve inter(aCur1, aCur2, IntPrec);
+       
+        for (int i = 1; i <= inter.Intersector().NbPoints(); i++)
+        {
+          double Param1 = inter.Intersector().Point(i).ParamOnFirst();
+          double Param2 = inter.Intersector().Point(i).ParamOnSecond();
+          double prec = 1e-5;
+          if (f + prec < Param1 && Param1 < l - prec && f2 + prec < Param2 && Param2 < l2 - prec)
+          {
+            // Save result of intersection to the map (edge -> seq. of parameters on it)
+            if (!myOutMapOfResult.IsBound(E1))
+            {
+              NCollection_Sequence<double> SeqOfParams;
+              SeqOfParams.Append(Param1);
+              myOutMapOfResult.Bind(E1, SeqOfParams);
+            }
+            else
+            {
+              NCollection_Sequence<double> Val = myOutMapOfResult(E1);
+              Val.Append(Param1);
+              myOutMapOfResult.Bind(E1, Val);
+            }
+
+           if (!myOutMapOfResult.IsBound(E2))
+           {
+             NCollection_Sequence<double> SeqOfParams;
+             SeqOfParams.Append(Param2);
+             myOutMapOfResult.Bind(E2, SeqOfParams);
+           }
+           else
+           {
+              NCollection_Sequence<double> Val = myOutMapOfResult(E2);
+              Val.Append(Param2);
+              myOutMapOfResult.Bind(E2, Val);
+           }
+           TopoDS_Vertex V;
+
+           // Make vertex from intersection point
+           double f_1, f_2, l_1, l_2;
+           TopLoc_Location Loc1, Loc2;
+           gp_Pnt p3d1, p3d2;
+           Handle_Geom_Curve aCur1 = BRep_Tool::Curve(E1, Loc1, f_1, l_1 ); 
+           Handle_Geom_Curve aCur2 = BRep_Tool::Curve(E2, Loc2, f_2, l_2 ); 
+	         aCur1->D0(Param1, p3d1);
+           aCur2->D0(Param2, p3d2);
+           if (!Loc1.IsIdentity())
+             p3d1.Transform(Loc1.Transformation());
+           if (!Loc2.IsIdentity())
+             p3d2.Transform(Loc2.Transformation());
+           gp_Pnt IntPnt((p3d1.X() + p3d2.X())/2., (p3d1.Y() + p3d2.Y())/2., (p3d1.Z() + p3d2.Z())/2.);  //middle point of two intersection points of edge1 & edge2
+           double TolE1 = BRep_Tool::Tolerance(E1);
+           double TolE2 = BRep_Tool::Tolerance(E2);
+           
+           myBuilder.MakeVertex(V, IntPnt, 1.01* ((TolE1 > TolE2 ? TolE1 : TolE2)  + (p3d1.Distance(p3d2)/2.)));
+
+           NCollection_List<BRepFill_BndBoxTreeSelector::EdgeParam> aList;
+           BRepFill_BndBoxTreeSelector::EdgeParam ep;
+
+           ep.myEdgeInt = E1;
+           ep.myParamInt = Param1;
+           ep.myIntVertex = V;
+           myListOfVertexEdgePar.Append(ep);
+
+           ep.myEdgeInt = E2;
+           ep.myParamInt = Param2;
+           ep.myIntVertex = V;
+           myListOfVertexEdgePar.Append(ep);
+
+           NCollection_Array1<int> anIndArr(1, 2);
+           anIndArr(1) = theObj;
+           anIndArr(2) = myCInd;
+           myEdgeIndexes.Append(anIndArr);
+           aCur1.Nullify();
+           aCur2.Nullify();
+          }
+        }
+        aCur1.Nullify();
+        aCur2.Nullify();
+
+
+      }
+    }
+    else //try to find self-intersection of edge
+    {
+      TopoDS_Edge E1 = TopoDS::Edge(mySeqOfEdges(theObj));
+      {
+        Handle_Geom2d_Curve aCur1;
+        double f, l;
+        aCur1 = BRep_Tool::CurveOnSurface(E1, myWFace, f, l ); 
+
+        double IntPrec = Precision::Confusion();
+        Geom2dAPI_InterCurveCurve inter(aCur1, IntPrec);
+       
+        for (int i = 1; i <= inter.Intersector().NbPoints(); i++)
+        {
+          double Param1 = inter.Intersector().Point(i).ParamOnFirst();
+          double Param2 = inter.Intersector().Point(i).ParamOnSecond();
+          double prec = 1e-5;
+          if (f + prec < Param1 && Param1 < l - prec && f + prec < Param2 && Param2 < l - prec)
+          {
+            // Save result of intersection to the map (edge -> seq. of parameters on it)
+            if (!myOutMapOfResult.IsBound(E1))
+            {
+              NCollection_Sequence<double> SeqOfParams;
+              SeqOfParams.Append(Param1);
+              SeqOfParams.Append(Param2);
+              myOutMapOfResult.Bind(E1, SeqOfParams);
+            }
+            else
+            {
+              NCollection_Sequence<double> Val = myOutMapOfResult(E1);
+              Val.Append(Param1);
+              Val.Append(Param2);
+              myOutMapOfResult.Bind(E1, Val);
+            }
+
+           // Make vertex from intersection point
+           TopoDS_Vertex V;
+
+           double f_1, l_1 ;
+           TopLoc_Location Loc1; 
+           gp_Pnt p3d1, p3d2;
+           Handle_Geom_Curve aCur1 = BRep_Tool::Curve(E1, Loc1, f_1, l_1 ); 
+	         aCur1->D0(Param1, p3d1);
+           aCur1->D0(Param2, p3d2);
+           if (!Loc1.IsIdentity())
+             p3d1.Transform(Loc1.Transformation());
+           gp_Pnt IntPnt((p3d1.X() + p3d2.X())/2., (p3d1.Y() + p3d2.Y())/2., (p3d1.Z() + p3d2.Z())/2.); 
+           double TolE1 = BRep_Tool::Tolerance(E1);
+           
+           myBuilder.MakeVertex(V, IntPnt, 1.01* (TolE1 + (p3d1.Distance(p3d2)/2.)));
+
+           NCollection_List<BRepFill_BndBoxTreeSelector::EdgeParam> aList;
+           BRepFill_BndBoxTreeSelector::EdgeParam ep;
+
+           ep.myEdgeInt = E1;
+           ep.myParamInt = Param1;
+           ep.myIntVertex = V;
+           myListOfVertexEdgePar.Append(ep);
+
+           ep.myEdgeInt = E1;
+           ep.myParamInt = Param2;
+           ep.myIntVertex = V;
+           myListOfVertexEdgePar.Append(ep);
+
+           NCollection_Array1<int> anIndArr(1, 2);
+           anIndArr(1) = theObj;
+           anIndArr(2) = theObj;
+           myEdgeIndexes.Append(anIndArr);
+           aCur1.Nullify();
+          }
+        }
+        aCur1.Nullify();
+
+      }
+    }
+    return Standard_True;
+  }
+
+  void ClearResult()
+  {
+    myOutMapOfResult.Clear();
+  }
+
+  void SetCurrentBox (const Bnd_Box2d& theBox, int theInd) 
+  { 
+    myCBox = theBox;
+    myCInd = theInd;
+  }
+
+  void GetResult( NCollection_DataMap<TopoDS_Edge, NCollection_Sequence<double>>& theOutMapOfResult)
+  {
+    theOutMapOfResult = myOutMapOfResult;
+  }
+
+  void GetListOfVertexEdgePar( NCollection_List<BRepFill_BndBoxTreeSelector::EdgeParam>& theOutList)
+  {
+    theOutList = myListOfVertexEdgePar;
+  }
+
+private:
+  TopTools_SequenceOfShape& mySeqOfEdges; //edges to be intersected with each other
+  const TopoDS_Face& myWFace; //work spine face
+  NCollection_DataMap<TopoDS_Edge, NCollection_Sequence<double>> myOutMapOfResult; // map "edge to it's intersection parameters"
+  NCollection_List<BRepFill_BndBoxTreeSelector::EdgeParam> myListOfVertexEdgePar;  
+  Bnd_Box2d myCBox;
+  int myCInd;
+  NCollection_List<NCollection_Array1<int>> myEdgeIndexes; //used to store already computed edge's indexes
+  BRep_Builder myBuilder; 
+};
+
+
+class Poly_Helper : public Poly_MakeLoops2D::Helper
+{
+public:
+  Poly_Helper(TopTools_IndexedMapOfShape& themN2V, 
+    TopTools_IndexedDataMapOfShapeListOfShape& themV2E, 
+    NCollection_DoubleMap<Poly_MakeLoops2D::Link, TopoDS_Edge>& themPL2E,
+    NCollection_DataMap<TopoDS_Edge, TopoLink>& themE2EInfo,
+    const NCollection_DataMap<int, Poly_MakeLoops2D::ListOfLink>& themNode2ListOfLinks) : 
+  mymN2V (themN2V), mymV2E (themV2E), mymPL2E (themPL2E), mymE2EInfo (themE2EInfo),
+  mymNode2ListOfLinks (themNode2ListOfLinks)
+  {
+    //Poly_MakeLoops2D::Helper();
+  };
+  Poly_Helper(const Poly_Helper& theOther) : Poly_MakeLoops2D::Helper(theOther), mymN2V (theOther.mymN2V), mymV2E (theOther.mymV2E), mymPL2E (theOther.mymPL2E), mymE2EInfo (theOther.mymE2EInfo),
+  mymNode2ListOfLinks (theOther.mymNode2ListOfLinks)
+  {
+  };
+
+  Poly_Helper& operator= (const Poly_Helper &theOther);
+
+  virtual const Poly_MakeLoops2D::ListOfLink& GetAdjacentLinks (Standard_Integer theNode) const
+  {
+    return mymNode2ListOfLinks(theNode);
+  }
+  virtual Standard_Boolean GetFirstTangent(const Poly_MakeLoops2D::Link& theLink, gp_Dir2d& theDir) const
+  {
+    TopoDS_Edge E = mymPL2E.Find1(theLink);
+    theDir = mymE2EInfo(E).myD1F;
+    return true;
+  }
+
+  virtual Standard_Boolean GetLastTangent(const Poly_MakeLoops2D::Link& theLink, gp_Dir2d& theDir) const
+  {
+    TopoDS_Edge E = mymPL2E.Find1(theLink);
+    theDir = mymE2EInfo(E).myD1L;
+    return true;
+  }
+
+private:
+  TopTools_IndexedMapOfShape& mymN2V;   //map 'node to vertex'
+  TopTools_IndexedDataMapOfShapeListOfShape& mymV2E; 
+  NCollection_DoubleMap<Poly_MakeLoops2D::Link, TopoDS_Edge>& mymPL2E; //map 'link to edge'
+  NCollection_DataMap<TopoDS_Edge, TopoLink>& mymE2EInfo;
+  const NCollection_DataMap<int, Poly_MakeLoops2D::ListOfLink>& mymNode2ListOfLinks;  //used internally by poly_makeloops algo  
+
+};
+
 //  Modified by Sergey KHROMOV - Thu Nov 16 17:24:39 2000 Begin
 
 static void QuasiFleche(const Adaptor3d_Curve& C,
@@ -224,6 +548,8 @@ static void MakeOffset
 
 Standard_Boolean CheckSmallParamOnEdge(const TopoDS_Edge& anEdge);
 
+static bool RemoveLoops(TopoDS_Shape& theInputSh, const TopoDS_Face& theWorkSpine, const Handle(Geom_Plane)& theRefPlane );
+
 //=======================================================================
 //function : KPartCircle
 //purpose  : 
@@ -1160,6 +1486,8 @@ void BRepFill_OffsetWire::PerformWithBiLo
   if (!myIsOpenResult)
     FixHoles();
 
+  RemoveLoops(myShape, myWorkSpine, RefPlane);
+
   myIsDone = Standard_True;
 }
 
@@ -2775,3 +3103,459 @@ Standard_Boolean CheckSmallParamOnEdge(const TopoDS_Edge& anEdge)
 }
 
 
+//! Used to remove loops from offset result
+static bool RemoveLoops(TopoDS_Shape& theInputSh, const TopoDS_Face& theWorkSpine, const Handle(Geom_Plane)& theRefPlane )
+{
+  Handle(BRepTools_ReShape) ExtReShape = new BRepTools_ReShape;
+
+  TopExp_Explorer Exp( theInputSh, TopAbs_WIRE );
+  
+  for (; Exp.More(); Exp.Next())   
+  {
+    Handle(BRepTools_ReShape) reshape = new BRepTools_ReShape;
+    TopoDS_Wire InitialW = TopoDS::Wire( Exp.Current() );
+    if (!InitialW.Closed())
+      continue;
+    TopoDS_Wire aW = TopoDS::Wire( Exp.Current() );
+
+    TopExp_Explorer ExpE( aW, TopAbs_EDGE );
+    TopTools_SequenceOfShape Seq; 
+    for (; ExpE.More(); ExpE.Next())
+      Seq.Append( ExpE.Current() );
+
+    NCollection_DataMap<TopoDS_Edge, NCollection_Sequence<double>> ME2IP;   //map edge to params on this edges
+    gp_Pln pl = theRefPlane->Pln();   
+
+    //Prepare UBTree filler
+    // Used to speedup the intersection process by using overlapped 2d bounding boxes 
+    BRepFill_BndBoxTree aTree;
+    NCollection_UBTreeFiller <Standard_Integer, Bnd_Box2d> aTreeFiller (aTree);
+    
+    BRepFill_BndBoxTreeSelector aSelector(Seq, theWorkSpine);
+
+    // Prepare bounding boxes
+    NCollection_Sequence<Bnd_Box2d> BndBoxesOfEdges;
+    for (int i = 1; i <= Seq.Length(); i++)
+    {
+      double f, l;
+      Handle_Geom2d_Curve aCur = BRep_Tool::CurveOnSurface(TopoDS::Edge(Seq(i)), theWorkSpine, f, l ); 
+      Bnd_Box2d aBox;
+      BndLib_Add2dCurve::Add( aCur, f, l, 0., aBox );
+      //aBox.Enlarge(1e-4);
+      aTreeFiller.Add(i, aBox);
+      BndBoxesOfEdges.Append(aBox);
+    }
+
+    aTreeFiller.Fill();
+    
+    //Perform searching and intersecting of edges
+    aSelector.ClearResult();
+    for (int i = 1; i <= BndBoxesOfEdges.Size(); i++)
+    {
+      aSelector.SetCurrentBox(BndBoxesOfEdges(i), i);
+      aTree.Select(aSelector);
+    }
+
+    aSelector.GetResult(ME2IP);  //Retrieve result from algo
+    NCollection_List<BRepFill_BndBoxTreeSelector::EdgeParam> LVEP;
+    aSelector.GetListOfVertexEdgePar(LVEP);
+
+    if (ME2IP.IsEmpty())
+      continue;           //if no intersection point => go to the next wire
+
+    TopTools_MapOfShape InterV; 
+    TopTools_IndexedMapOfShape EdgesInInter; 
+
+    for (NCollection_DataMap<TopoDS_Edge, NCollection_Sequence<double>>::Iterator aMapIt (ME2IP); aMapIt.More(); aMapIt.Next()) 
+    {
+      TopoDS_Edge E = aMapIt.Key();
+      NCollection_Sequence<double> Params = aMapIt.Value(); 
+      Handle_Geom_Curve aCur;
+      double f, l;
+      aCur = BRep_Tool::Curve(E, f, l );
+      
+      //prepare params on the edge
+      NCollection_Sequence<double> ParamSeq;
+      ParamSeq.Append(f);
+      ParamSeq.Append(l);
+      ParamSeq.Append(Params);
+
+      //sort parameters
+      NCollection_QuickSort<NCollection_Sequence<double>, double>::Perform(ParamSeq, NCollection_Comparator<double>(), ParamSeq.Lower(), ParamSeq.Upper());
+      NCollection_Sequence<TopoDS_Vertex> aVOnEdge;  //Vertexes on the edge which divide it in the intersection points into sequence of edges
+      NCollection_Sequence<TopoDS_Edge> NewEdgeSeq;
+      TopoDS_Vertex VF, VL;
+      VF = TopExp::FirstVertex(E);
+      VL = TopExp::LastVertex(E);
+      aVOnEdge.Append(VF);
+      
+      for (int i = 2; i <= ParamSeq.Length() - 1; i++)
+      {
+        double P = ParamSeq(i);
+        TopoDS_Vertex MV;
+        for (NCollection_List<BRepFill_BndBoxTreeSelector::EdgeParam>::Iterator anIt (LVEP); anIt.More(); anIt.Next())
+        {
+          BRepFill_BndBoxTreeSelector::EdgeParam ep = anIt.Value();
+          if (ep.myEdgeInt == E && ep.myParamInt == P)
+          {
+            MV = anIt.Value().myIntVertex;
+            InterV.Add(MV);
+            break;
+          }
+        }
+
+        aVOnEdge.Append(MV);
+      }
+      aVOnEdge.Append(VL);
+
+      //Split old edge => Construct a new sequence of new edges
+      TopoDS_Edge DE;
+      for (int j = 1; j < aVOnEdge.Length(); j++)
+      {
+        DE = BRepBuilderAPI_MakeEdge(aCur, aVOnEdge(j), aVOnEdge(j+1), ParamSeq(j), ParamSeq(j+1));
+        BRep_Builder BB;
+        BB.UpdateEdge(DE, BRep_Tool::Tolerance(E));
+        NewEdgeSeq.Append(DE);
+      }
+
+      BRepBuilderAPI_MakeWire MW;
+      for (int i = 1; i <= NewEdgeSeq.Length(); i++)
+      {
+        MW.Add(NewEdgeSeq(i));
+        EdgesInInter.Add(NewEdgeSeq(i));
+      }
+      MW.Build();
+      TopoDS_Wire TW = MW.Wire(); //make wire from the sequence of edges
+      TW.Orientation(E.Orientation());
+      reshape->Replace(E, TW);   //replace old edge with wire
+    }
+
+    aW = TopoDS::Wire(reshape->Apply(aW));
+
+    // Prepare wire for Poly_MakeLoops algo:
+    // Insert neccesary vertices if two edges shares same (two) vertices
+    bool Stat = true;
+    for (int i = 1; i <= EdgesInInter.Extent() && Stat; i++)
+      for (int j = i; j <= EdgesInInter.Extent() && Stat; j++)
+      {
+        TopoDS_Edge E1 = TopoDS::Edge(EdgesInInter(i));
+        TopoDS_Edge E2 = TopoDS::Edge(EdgesInInter(j));
+        if (E1 == E2)
+          continue;
+        TopoDS_Vertex VF1, VL1, VF2, VL2;
+        TopExp::Vertices(E1, VF1, VL1);
+        TopExp::Vertices(E2, VF2, VL2);
+        if ((VF1.IsSame(VF2) && VL1.IsSame(VL2)) || (VF1.IsSame(VL2) && VL1.IsSame(VF2)))
+        {
+          gp_Pnt MP;
+          Handle_Geom_Curve cur;
+          double f, l;
+          cur = BRep_Tool::Curve(E1, f, l);
+          cur->D0(f + (l-f)/2., MP);
+          TopoDS_Vertex MV = BRepLib_MakeVertex(MP);
+          TopoDS_Edge DE1, DE2;
+          BRepBuilderAPI_MakeEdge MEB;
+          MEB.Init(cur, VF1, MV, f, f + (l-f)/2 );
+          if (!MEB.IsDone()) {
+            Stat = false;
+            break;
+          }
+          DE1 = MEB.Edge();
+          MEB.Init(cur, MV, VL1, f + (l-f)/2, l );
+          if (!MEB.IsDone()) {
+            Stat = false;
+            break;
+          }
+          DE2 = MEB.Edge();
+          TopoDS_Wire W = BRepBuilderAPI_MakeWire(DE1, DE2);
+          TopTools_IndexedMapOfShape DummyM;
+          TopExp::MapShapes(W, TopAbs_VERTEX, DummyM);
+          if (DummyM.Extent() !=3 ) 
+          {
+            Stat = false;
+            break;
+          }
+          reshape->Replace(E1, W.Oriented(E1.Orientation()));
+        }
+      }
+
+    aW = TopoDS::Wire(reshape->Apply(aW));
+    // If edges contains only one vertex => insert another two vertices
+    ExpE.Init( aW, TopAbs_EDGE );
+    for (; ExpE.More() && Stat; ExpE.Next())
+    {
+      TopoDS_Edge E = TopoDS::Edge(ExpE.Current());
+      TopoDS_Vertex VF, VL;      
+      TopExp::Vertices(E, VF, VL);
+
+      if (VF.IsSame( VL ) && (InterV.Contains(VL) || InterV.Contains(VF)))
+      {
+        gp_Pnt MP1, MP2;
+        Handle_Geom_Curve cur;
+        double f, l;
+        cur = BRep_Tool::Curve(E, f, l);
+        if ( Abs(l - f ) <  3 * Precision::Confusion())
+          continue;
+        cur->D0(f + (0.3)*(l-f), MP1);
+        cur->D0(f + (0.6)*(l-f), MP2);
+        TopoDS_Vertex MV1 = BRepLib_MakeVertex(MP1);
+        TopoDS_Vertex MV2 = BRepLib_MakeVertex(MP2);
+        BRepBuilderAPI_MakeEdge MEB;
+        TopoDS_Edge DE1, DE2, DE3;
+        MEB.Init(cur, VF, MV1, f, f + (0.3)*(l-f) );
+        if (!MEB.IsDone()) {
+          Stat = false;
+          break;
+        }
+        DE1 = MEB.Edge();
+        MEB.Init(cur, MV1, MV2, f + (0.3)*(l-f), f + (0.6)*(l-f) );
+        if (!MEB.IsDone()) {
+          Stat = false;
+          break;
+        }
+        DE2 = MEB.Edge();
+        MEB.Init(cur, MV2, VL, f + (0.6)*(l-f), l );
+        if (!MEB.IsDone()) {
+          Stat = false;
+          break;
+        }
+        DE3 = MEB.Edge();
+        TopoDS_Wire W = BRepBuilderAPI_MakeWire(DE1, DE2, DE3);
+        TopTools_IndexedMapOfShape DummyM;
+        TopExp::MapShapes(W, TopAbs_VERTEX, DummyM);
+        if (DummyM.Extent() !=3 ) 
+        {
+          Stat = false;
+          break;
+        }
+        reshape->Replace(E, W.Oriented(E.Orientation()));
+      }
+    }
+    if (!Stat)
+      continue;
+    
+    //Perform reorder of wire
+    aW = TopoDS::Wire(reshape->Apply(aW));
+    Handle(ShapeExtend_WireData) aWireData  = new ShapeExtend_WireData;
+    Handle(ShapeFix_Wire) aShFixWire = new ShapeFix_Wire;
+    
+    Handle(ShapeAnalysis_Wire) aWireAnalyzer;
+    ShapeAnalysis_WireOrder aWireOrder;
+
+    aShFixWire->Load(aWireData);
+    aShFixWire->SetPrecision(1e-7);
+
+    TopExp_Explorer Exp1( aW, TopAbs_EDGE );
+    for (; Exp1.More(); Exp1.Next())
+      aWireData->Add(TopoDS::Edge(Exp1.Current()));            
+
+    aWireOrder.KeepLoopsMode() = 0;
+    aWireAnalyzer = aShFixWire->Analyzer();
+    aShFixWire->ModifyTopologyMode() = Standard_True;
+    //aShFixWire->FixConnected(1e-7);
+    aWireAnalyzer->CheckOrder(aWireOrder, Standard_True);
+    aWireOrder.Perform(1);
+    aShFixWire->ClosedWireMode() = 1;
+    aShFixWire->FixReorder(aWireOrder);
+    //aShFixWire->FixDegenerated();
+    bool IsDone = !aShFixWire->StatusReorder(ShapeExtend_FAIL);
+    
+    if (!IsDone)
+      continue;
+
+    aW = aWireData->Wire();
+
+ 
+    if (Stat)
+    {
+      aW = TopoDS::Wire(reshape->Apply(aW));
+      
+      // Prepare 'TopoLink' info for Poly_MakeLoops algo => Calculate derivatives of the edges
+      NCollection_DataMap<TopoDS_Edge, TopoLink> mE2EInfo;
+      ExpE.Init(aW, TopAbs_EDGE);
+      for (; ExpE.More(); ExpE.Next())
+      {
+        TopoLink anEngeInfo;
+        TopoDS_Edge E = TopoDS::Edge(ExpE.Current());
+        Handle_Geom2d_Curve aCur;
+        double f, l;
+        gp_Pnt2d Pnt;
+        gp_Vec2d Vec;
+
+        aCur = BRep_Tool::CurveOnSurface(E, theWorkSpine, f, l ); 
+        if (aCur.IsNull())
+          continue;
+        if (E.Orientation() == TopAbs_FORWARD)
+        {
+          anEngeInfo.myFV = TopExp::FirstVertex(E); 
+          anEngeInfo.myLV = TopExp::LastVertex(E); 
+          aCur->D1(f, Pnt, Vec);
+          anEngeInfo.myD1F.SetCoord(Vec.X(), Vec.Y());
+          aCur->D1(l, Pnt, Vec);
+          anEngeInfo.myD1L.SetCoord(Vec.X(), Vec.Y());
+        }
+        else
+        {
+          anEngeInfo.myFV = TopExp::LastVertex(E); 
+          anEngeInfo.myLV = TopExp::FirstVertex(E); 
+          aCur->D1(l, Pnt, Vec);
+          anEngeInfo.myD1F.SetCoord(-Vec.X(), -Vec.Y());
+          aCur->D1(f, Pnt, Vec);
+          anEngeInfo.myD1L.SetCoord(-Vec.X(), -Vec.Y());
+        }
+        mE2EInfo.Bind(E, anEngeInfo);
+      }
+
+      TopTools_IndexedMapOfShape mN2V;
+      TopExp::MapShapes(aW, TopAbs_VERTEX, mN2V);
+
+      TopTools_IndexedDataMapOfShapeListOfShape mV2E;
+      TopExp::MapShapesAndAncestors(aW, TopAbs_VERTEX, TopAbs_EDGE, mV2E);
+
+      //Create links for Poly_MakeLoops algo and bind them to the existing edges
+      NCollection_DoubleMap<Poly_MakeLoops2D::Link, TopoDS_Edge> mPL2E;
+      ExpE.Init(aW, TopAbs_EDGE);
+      for (; ExpE.More(); ExpE.Next())
+      {
+        TopoDS_Edge E = TopoDS::Edge(ExpE.Current());
+        if (!mE2EInfo.IsBound(E))
+          continue;
+        TopoLink L = mE2EInfo(E);
+        int Node1 = mN2V.FindIndex(L.myFV);
+        int Node2 = mN2V.FindIndex(L.myLV);
+        Poly_MakeLoops2D::Link aLink(Node1, Node2);
+        aLink.flags = Poly_MakeLoops2D::LF_Fwd;
+        mPL2E.Bind(aLink, E);
+      }
+
+      NCollection_DataMap<int, Poly_MakeLoops2D::ListOfLink> mNode2ListOfLinks;
+      for (int i = 1; i <= mN2V.Extent(); i++)
+      {
+        TopoDS_Vertex V = TopoDS::Vertex(mN2V(i));
+        TopTools_ListOfShape Edges = mV2E.FindFromKey(V);
+        TopTools_ListIteratorOfListOfShape It(Edges);
+        Poly_MakeLoops2D::ListOfLink aListOfLinks;
+        for (;It.More(); It.Next())
+        {
+          TopoDS_Edge E = TopoDS::Edge(It.Value());
+          if (!mPL2E.IsBound2(E))
+            continue;
+          Poly_MakeLoops2D::Link aL = mPL2E.Find2(E);
+          aListOfLinks.Append(aL);
+        }
+        mNode2ListOfLinks.Bind(i, aListOfLinks);
+      }
+
+      Poly_Helper helper(mN2V, mV2E, mPL2E, mE2EInfo, mNode2ListOfLinks);
+      Poly_MakeLoops2D aLoopMaker(1, &helper, NCollection_BaseAllocator::CommonBaseAllocator() );
+      for (NCollection_DoubleMap<Poly_MakeLoops2D::Link, TopoDS_Edge>::Iterator aMapIt (mPL2E); aMapIt.More(); aMapIt.Next())
+        aLoopMaker.AddLink(aMapIt.Key1());
+      
+      aLoopMaker.Perform();   //try to find loops
+      int NbLoops = aLoopMaker.GetNbLoops();
+      int NbHangs = aLoopMaker.GetNbHanging();
+
+      if (NbLoops == 0 || NbHangs != 0 ) 
+        continue;
+
+      NCollection_Sequence<TopoDS_Wire> aLoops;
+      for (int i = 1; i <= NbLoops; i++)  //try to construct loops
+      {
+        Poly_MakeLoops2D::Loop aLoop = aLoopMaker.GetLoop(i);
+        Poly_MakeLoops2D::Loop::Iterator it(aLoop);
+        BRepBuilderAPI_MakeWire aWM;
+        TopoDS_Edge E;
+        for (;it.More(); it.Next())
+        {
+          E = mPL2E.Find1(it.Value());
+          aWM.Add(E);
+        }
+        if (aWM.IsDone())
+        {
+          TopoDS_Wire W = aWM.Wire();
+          if (!W.Closed())
+          {
+            Stat = false;
+            break;
+          }
+          aLoops.Append(W);
+        }
+      }
+
+      if (!Stat)
+        continue;
+      
+      // try to classify wires
+      NCollection_Sequence<TopoDS_Wire> InnerMWires; // interior wires
+      NCollection_Sequence<TopoDS_Wire> ExtMWires; //wires which defines a hole
+      for (int i = 1; i <= aLoops.Length(); i++)
+      {
+        TopoDS_Face af = BRepBuilderAPI_MakeFace (theRefPlane, Precision::Confusion() ); //TopoDS::Face ( myWorkSpine.EmptyCopied() );
+        af.Orientation ( TopAbs_REVERSED );
+        BRep_Builder BB;  
+        BB.Add (af, aLoops(i));
+ 
+        BRepTopAdaptor_FClass2d FClass(af, Precision::PConfusion());
+        if (FClass.PerformInfinitePoint() == TopAbs_OUT)
+          InnerMWires.Append(aLoops(i));
+        else
+          ExtMWires.Append(aLoops(i));
+      }
+
+      if (InnerMWires.Length() == ExtMWires.Length())
+        continue; 
+
+      if (InnerMWires.Length() < ExtMWires.Length())
+        //probably incorrect orientation 
+        continue; 
+      //try to find an outer wire
+      int IndOfOuterW = -1;
+      for (int i = 1; i <= InnerMWires.Length(); i++)
+      {
+        bool IsInside = true;
+        BRepBuilderAPI_MakeFace aDB(theRefPlane, InnerMWires(i));
+        TopoDS_Face aDummyFace = TopoDS::Face(aDB.Shape());
+        BRepTopAdaptor_FClass2d FClass(aDummyFace, Precision::PConfusion());
+        for (int j = 1; j <= InnerMWires.Length(); j++)
+        {              
+          if ( i == j )
+            continue;
+          double f, l;
+          TopExp_Explorer ExpE( InnerMWires(j), TopAbs_EDGE );
+          Handle_Geom2d_Curve aCur = BRep_Tool::CurveOnSurface(TopoDS::Edge(ExpE.Current()), theWorkSpine, f, l ); 
+                    
+          gp_Pnt2d MP = aCur->Value((l + f) / 2.0);
+          if (FClass.Perform(MP) != TopAbs_IN)
+          {
+            IsInside = false;
+            break;
+          }
+        }
+        if (IsInside)
+        {
+          IndOfOuterW = i;
+          break;
+        }
+
+      }
+
+      if (IndOfOuterW == -1)
+        continue; //cant find an outer wire
+
+      TopoDS_Wire OuterWire = InnerMWires(IndOfOuterW);
+      //make compound: outer wire + holes
+      BRep_Builder BBC;
+      TopoDS_Compound Co; 
+      BBC.MakeCompound(Co);
+      BBC.Add(Co, OuterWire);
+
+      for (int i = 1; i <= ExtMWires.Length(); i++)
+        BBC.Add(Co, ExtMWires(i));
+
+      ExtReShape->Replace(InitialW, Co);
+    }
+  }
+
+  theInputSh = ExtReShape->Apply(theInputSh);
+  return true;
+}