path: root/src/ChFi3d/ChFi3d_Builder_C1.cxx

// File:	ChFi3d_Builder_3.cxx
// Created:	Wed Mar  9 15:48:03 1994
// Author:	Isabelle GRIGNON
//		<isg@zerox>

//  Modified by skv - Mon Jun  7 18:38:57 2004 OCC5898
//  Modified by skv - Thu Aug 21 11:55:58 2008 OCC20222

#include <ChFi3d_Builder.jxx>
#include <ChFi3d.hxx>
#include <ChFi3d_Builder_0.hxx>

#include <Precision.hxx>

#include <Standard_Failure.hxx>
#include <Standard_NotImplemented.hxx>
#include <StdFail_NotDone.hxx>


#include <gp_Pnt.hxx>
#include <gp_Dir.hxx>
#include <gp_Vec.hxx>
#include <gp_Ax3.hxx>
#include <gp_Pnt2d.hxx>
#include <gp_Vec2d.hxx>
#include <gp_Dir2d.hxx>
#include <gp_Elips.hxx>
#include <gp_Circ.hxx>

#include <ElCLib.hxx>
#include <ElSLib.hxx>

#include <Geom_Line.hxx>
#include <Geom_Circle.hxx>
#include <Geom_Ellipse.hxx>
#include <Geom_RectangularTrimmedSurface.hxx>
#include <Geom_Curve.hxx>
#include <Geom2d_Line.hxx>
#include <Geom2d_Curve.hxx>
#include <Geom_BSplineCurve.hxx>
#include <Geom_BSplineSurface.hxx>
#include <Geom_BezierSurface.hxx>
#include <Geom2d_BSplineCurve.hxx>
#include <Geom2dAdaptor_HCurve.hxx>
#include <Geom2d_TrimmedCurve.hxx>
#include <Geom2dInt_GInter.hxx>
#include <Geom_TrimmedCurve.hxx>
#include <GeomAPI_ExtremaCurveCurve.hxx>
#include <GeomAbs_Shape.hxx>
#include <GeomAdaptor_HCurve.hxx>
#include <GeomAdaptor_Surface.hxx>
#include <GeomAdaptor_HSurface.hxx>
#include <Geom_BoundedCurve.hxx>
#include <GeomLib.hxx>
#include <GeomInt_IntSS.hxx>
#include <GeomProjLib.hxx>

#include <Adaptor3d_HCurveOnSurface.hxx>
#include <Adaptor3d_CurveOnSurface.hxx>
#include <BRepAdaptor_HSurface.hxx>
#include <BRepAdaptor_Curve.hxx>
#include <BRepAdaptor_Curve2d.hxx>
#include <BRepAdaptor_HCurve2d.hxx>
#include <BRepAdaptor_HCurve.hxx>
#include <BRepAdaptor_Surface.hxx>
#include <BRepLib_MakeEdge.hxx>
#include <BRepAlgo_NormalProjection.hxx>
#include <BRepExtrema_ExtCC.hxx>
#include <BRep_Tool.hxx>
#include <BRepTools.hxx>
#include <BRep_Builder.hxx>
#include <IntCurveSurface_HInter.hxx>
#include <IntCurveSurface_IntersectionPoint.hxx>
#include <IntRes2d_IntersectionPoint.hxx>
#include <IntRes2d_Transition.hxx>
#include <Extrema_LocateExtCC.hxx>
#include <Extrema_POnCurv.hxx>
#include <Extrema_ExtPC2d.hxx>
#include <Extrema_ExtPC.hxx>
#include <Extrema_ExtPS.hxx>
#include <Extrema_ExtCC.hxx>

#include <TopoDS.hxx>
#include <TopoDS_Shape.hxx>
#include <TopoDS_Face.hxx>
#include <TopoDS_Edge.hxx>
#include <TopoDS_Vertex.hxx>

#include <TopAbs.hxx>
#include <TopAbs_ShapeEnum.hxx>
#include <TopAbs_Orientation.hxx>
#include <TopExp.hxx>
#include <TopExp_Explorer.hxx>
#include <TopLoc_Location.hxx>
#include <TopTools_ListIteratorOfListOfShape.hxx>

#include <TopOpeBRepDS_Point.hxx>
#include <TopOpeBRepDS_Curve.hxx>
#include <TopOpeBRepDS_Surface.hxx>
#include <TopOpeBRepDS_SurfaceCurveInterference.hxx>
#include <TopOpeBRepDS_CurvePointInterference.hxx>
#include <TopOpeBRepDS_DataStructure.hxx>
#include <TopOpeBRepDS_ListOfInterference.hxx>
#include <TopOpeBRepDS_ListIteratorOfListOfInterference.hxx>
#include <TopOpeBRepDS_SolidSurfaceInterference.hxx>
#include <TopOpeBRepDS_Kind.hxx>
#include <TopOpeBRepDS_Transition.hxx>
#include <TopTools_Array1OfShape.hxx>
#include <ChFiDS_HData.hxx>
#include <ChFiDS_SurfData.hxx>
#include <ChFiDS_CommonPoint.hxx>
#include <ChFiDS_FaceInterference.hxx>
#include <ChFiDS_SequenceOfSurfData.hxx>
#include <ChFiDS_Stripe.hxx>
#include <ChFiDS_ListIteratorOfListOfStripe.hxx>
#include <ChFiDS_Map.hxx>
#include <TColgp_Array1OfPnt.hxx>
#include <TColgp_Array1OfPnt2d.hxx>
#include <TColStd_Array1OfReal.hxx>
#include <TColStd_Array1OfInteger.hxx>

#ifdef DEB
# ifdef DRAW
#include <OSD_Chronometer.hxx>
#include <DrawTrSurf.hxx>
# endif //DRAW
//  Modified by Sergey KHROMOV - Thu Apr 11 12:23:40 2002 Begin
// The method
// ChFi3d_Builder::PerformMoreSurfdata(const Standard_Integer Index)
// is totally rewroted.
//  Modified by Sergey KHROMOV - Thu Apr 11 12:23:40 2002 End

extern Standard_Real  t_same,t_inter,t_sameinter;
extern void ChFi3d_InitChron(OSD_Chronometer& ch);
extern void ChFi3d_ResultChron(OSD_Chronometer & ch,Standard_Real& time);
#endif
#include <Geom2dAPI_ProjectPointOnCurve.hxx>
#include <math_FunctionSample.hxx>
#include <Geom2dAdaptor_Curve.hxx>
#include <IntRes2d_IntersectionSegment.hxx>
//  Modified by Sergey KHROMOV - Fri Dec 21 17:08:19 2001 Begin
Standard_Boolean isTangentFaces(const TopoDS_Edge &theEdge,
				const TopoDS_Face &theFace1,
				const TopoDS_Face &theFace2);
//  Modified by Sergey KHROMOV - Fri Dec 21 17:08:19 2001 End

static Standard_Real recadre(const Standard_Real p,
			     const Standard_Real ref,
			     const Standard_Boolean isfirst,
			     const Standard_Real first,
			     const Standard_Real last)
{
  Standard_Real pp = p;
  if (isfirst) pp -= (last - first);
  else pp += (last - first);
  if (Abs(pp - ref) < Abs(p - ref)) return pp;
  return p;
}

//=======================================================================
//function : Update
//purpose  : Calculate the intersection of the face at the end of 
//           the tangency line to update CommonPoint and its 
//           parameter in FaceInterference.
//=======================================================================

static Standard_Boolean Update(Handle(Adaptor3d_HSurface)& fb,
			       Handle(Adaptor2d_HCurve2d)& pcfb,
			       Handle(Adaptor3d_HSurface)& surf,
			       ChFiDS_FaceInterference&  fi,
			       ChFiDS_CommonPoint&       cp,
			       gp_Pnt2d&                 p2dbout,
			       const Standard_Boolean    isfirst,
			       Standard_Real&            pared,
			       Standard_Real&            wop,
			       const Standard_Real       tol)
{
  Adaptor3d_CurveOnSurface c1(pcfb,fb);
  Handle(Geom2d_Curve) pc = fi.PCurveOnSurf();
  Handle(Geom2dAdaptor_HCurve) hpc = new Geom2dAdaptor_HCurve(pc);
  Adaptor3d_CurveOnSurface c2(hpc,surf);
  Extrema_LocateExtCC ext(c1,c2,pared,wop);
  if (ext.IsDone()) {
    Standard_Real dist2 = ext.SquareDistance();
    if (dist2 < tol * tol) {
      Extrema_POnCurv ponc1,ponc2;
      ext.Point(ponc1,ponc2);
      Standard_Real parfb = ponc1.Parameter();
      p2dbout = pcfb->Value(parfb);
      pared = ponc1.Parameter();
      wop = ponc2.Parameter();
      fi.SetParameter(wop,isfirst);
      cp.Reset();
      cp.SetPoint(ponc1.Value());
      return Standard_True;
    }
  }
  return Standard_False;
}

//=======================================================================
//function : Update
//purpose  : Intersect surface <fb> and 3d curve <ct>
//           Update <isfirst> parameter of FaceInterference <fi> and point of
//           CommonPoint <cp>. Return new intersection parameters in <wop>
//           and <p2dbout>
//=======================================================================

static Standard_Boolean Update(Handle(Adaptor3d_HSurface)& fb,
			       Handle(Adaptor3d_HCurve)&   ct,
			       ChFiDS_FaceInterference&  fi,
			       ChFiDS_CommonPoint&       cp,
			       gp_Pnt2d&                 p2dbout,
			       const Standard_Boolean    isfirst,
			       Standard_Real&            wop)
{
  IntCurveSurface_HInter Intersection;
  //check if in KPart the limits of the tangency line 
  //are already in place at this stage.
  //Modif lvt : the periodic cases are reframed, espercially if nothing was found.
  Standard_Real w,uf = ct->FirstParameter(),ul = ct->LastParameter();
#ifndef DEB
  Standard_Real  wbis = 0.;
#else
  Standard_Real  wbis;
#endif
  Standard_Boolean isperiodic = ct->IsPeriodic(),recadrebis = Standard_False;
  Intersection.Perform(ct,fb);
  if (Intersection.IsDone()) {
    Standard_Integer nbp = Intersection.NbPoints(),i,isol = 0,isolbis = 0;
    Standard_Real dist = Precision::Infinite();
    Standard_Real distbis = Precision::Infinite();
    for (i = 1; i <= nbp; i++) {
      w = Intersection.Point(i).W();
      if (isperiodic) w = recadre(w,wop,isfirst,uf,ul);
      if (uf <= w && ul >= w && Abs(w-wop) < dist) {
	isol = i;
	dist = Abs(w-wop);
      }
    }
    if (isperiodic) {
      for (i = 1; i <= nbp; i++) {
	w = Intersection.Point(i).W();
	if (uf <= w && ul >= w && Abs(w-wop) < distbis && (Abs(w-ul)<=0.01 || Abs(w-uf)<=0.01)) {
	  isolbis = i;
	  wbis = recadre(w,wop,isfirst,uf,ul);
	  distbis = Abs(wbis-wop);
	  recadrebis = Standard_True;
	}
      }
    }
    if (isol == 0 && isolbis == 0) {
      return Standard_False;
    }
    if (!recadrebis) {
      IntCurveSurface_IntersectionPoint pint = Intersection.Point(isol);
      p2dbout.SetCoord(pint.U(),pint.V());
      w = pint.W();
      if (isperiodic) w = ElCLib::InPeriod(w,uf,ul);
    }
    else {
      if (dist>distbis) {
	IntCurveSurface_IntersectionPoint pint = Intersection.Point(isolbis);
	p2dbout.SetCoord(pint.U(),pint.V());
	w = wbis;
      }
      else {
	IntCurveSurface_IntersectionPoint pint = Intersection.Point(isol);
	p2dbout.SetCoord(pint.U(),pint.V());
	w = pint.W();
	w = ElCLib::InPeriod(w,uf,ul);
      }
    }
    fi.SetParameter(w,isfirst);
    cp.Reset();
    cp.SetPoint(ct->Value(w));
    wop = w;
    return Standard_True;
  }
  return Standard_False;
}

//=======================================================================
//function : IntersUpdateOnSame
//purpose  : Intersect  curve <c3dFI> of ChFi-<Fop> interference with extended
//           surface <HBs> of <Fprol> . Return intersection parameters in
//           <FprolUV>, <c3dU> and updating <FIop> and <CPop>
//           <HGs> is a surface of ChFi
//           <Fop> is a face having 2 edges at corner with OnSame state
//           <Fprol> is a face non-adjacent to spine edge
//           <Vtx> is a corner vertex
//=======================================================================

static Standard_Boolean IntersUpdateOnSame(Handle(GeomAdaptor_HSurface)& HGs,
					   Handle(BRepAdaptor_HSurface)& HBs,
					   const Handle(Geom_Curve)&     c3dFI,
					   const TopoDS_Face&            Fop,
					   const TopoDS_Face&            Fprol,
					   const TopoDS_Edge&            Eprol,
					   const TopoDS_Vertex&          Vtx,
					   const Standard_Boolean        isFirst,
					   const Standard_Real           Tol,
					   ChFiDS_FaceInterference&      FIop,
					   ChFiDS_CommonPoint&           CPop,
					   gp_Pnt2d&                     FprolUV,
					   Standard_Real&                c3dU)
{
  // add more or less restrictive criterions to
  // decide if the intersection is done with the face at 
  // extended end or if the end is sharp.
  Standard_Real uf = FIop.FirstParameter();
  Standard_Real ul = FIop.LastParameter();
  Handle(GeomAdaptor_HCurve) Hc3df;
  if (c3dFI->IsPeriodic()) Hc3df = new GeomAdaptor_HCurve(c3dFI);
  else                     Hc3df = new GeomAdaptor_HCurve(c3dFI,uf,ul);

  if ( Update(HBs,Hc3df,FIop,CPop,FprolUV,isFirst,c3dU) )
    return Standard_True;

  if (!isTangentFaces(Eprol,Fprol,Fop))
    return Standard_False;

  Handle(Geom2d_Curve) gpcprol = BRep_Tool::CurveOnSurface(Eprol,Fprol,uf,ul);
  Handle(Geom2dAdaptor_HCurve) pcprol = new Geom2dAdaptor_HCurve(gpcprol);
  Standard_Real partemp = BRep_Tool::Parameter(Vtx,Eprol);

  return
    Update(HBs,pcprol,HGs,FIop,CPop,FprolUV,isFirst,partemp,c3dU,Tol);
}

//=======================================================================
//function : Update
//purpose  : Calculate the extrema curveonsurf/curveonsurf to prefer 
//           the values concerning the trace on surf and the pcurve on the
//           face at end.
//=======================================================================

static Standard_Boolean Update(Handle(Adaptor3d_HSurface)& face,
			       Handle(Adaptor2d_HCurve2d)& edonface,
			       Handle(Adaptor3d_HSurface)& surf,
			       ChFiDS_FaceInterference&  fi,
			       ChFiDS_CommonPoint&       cp,
			       const Standard_Boolean    isfirst)
{
  if (!cp.IsOnArc()) return 0;
  Adaptor3d_CurveOnSurface c1(edonface,face);
  Standard_Real pared = cp.ParameterOnArc();
  Standard_Real parltg = fi.Parameter(isfirst);
  Handle(Geom2d_Curve) pc = fi.PCurveOnSurf();
  Standard_Real f = fi.FirstParameter();
  Standard_Real l = fi.LastParameter();
  Standard_Real delta = 0.1 * ( l - f );
  f = Max(f-delta,pc->FirstParameter());
  l = Min(l+delta,pc->LastParameter());
  Handle(Geom2dAdaptor_HCurve) hpc = new Geom2dAdaptor_HCurve(pc,f,l);
  Adaptor3d_CurveOnSurface c2(hpc,surf);

  Extrema_LocateExtCC ext(c1,c2,pared,parltg);
  if (ext.IsDone()) {
    Extrema_POnCurv ponc1,ponc2;
    ext.Point(ponc1,ponc2);
    pared = ponc1.Parameter();
    parltg = ponc2.Parameter();
    if ((parltg > f) && (parltg < l)) {
      fi.SetParameter(parltg,isfirst);
      cp.SetArc(cp.Tolerance(),cp.Arc(),pared,cp.TransitionOnArc());
      return Standard_True;
    }
  }
  return Standard_False;
}

//=======================================================================
//function : ChFi3d_ExtendSurface
//purpose  :
//=======================================================================

static void ChFi3d_ExtendSurface (Handle(Geom_Surface) & S ,
                                  Standard_Integer & prol )
{
  if (prol) return;
  Handle(Geom_BSplineSurface) S1;
  Handle(Geom_BezierSurface) S2;
  Standard_Real length,umin,umax,vmin,vmax;
  gp_Pnt P1,P2;
  S->Bounds(umin,umax,vmin,vmax);
  S->D0(umin,vmin,P1);
  S->D0(umax,vmax,P2);
  length=P1.Distance(P2);
  prol=0;
  S1=Handle(Geom_BSplineSurface)::DownCast(S);
  S2=Handle(Geom_BezierSurface)::DownCast(S);
  if (!S1.IsNull()) {
                  GeomLib::ExtendSurfByLength(S1,length,1,Standard_False,
                  Standard_True);
                  GeomLib::ExtendSurfByLength(S1,length,1,Standard_True,
                  Standard_True);
                  GeomLib::ExtendSurfByLength(S1,length,1,Standard_False,
                  Standard_False);
                  GeomLib::ExtendSurfByLength(S1,length,1,Standard_True,
                  Standard_False);
                  S=S1;
                  prol=1;
   }
   if (!S2.IsNull()) {
                 GeomLib::ExtendSurfByLength(S2,length,1,Standard_False,
                 Standard_True);
                 GeomLib::ExtendSurfByLength(S2,length,1,Standard_True,
                 Standard_True);
                 GeomLib::ExtendSurfByLength(S2,length,1,Standard_False,
                 Standard_False);
                 GeomLib::ExtendSurfByLength(S2,length,1,Standard_True,
                 Standard_False);
                 S=S2;
                 prol=2;

  }
}

//=======================================================================
//function : ComputeCurve2d
//purpose  : calculate the 2d of the curve Ct on face Face
//=======================================================================

static void  ComputeCurve2d (Handle(Geom_Curve )& Ct,
                       TopoDS_Face & Face,
                       Handle(Geom2d_Curve) & C2d)
{
  TopoDS_Edge E1;
  TopTools_IndexedMapOfShape MapE1;
  BRepLib_MakeEdge Bedge (Ct);
  TopoDS_Edge edg =Bedge. Edge();
  BRepAlgo_NormalProjection OrtProj;
  OrtProj.Init(Face);
  OrtProj.Add(edg);
  OrtProj.SetParams(1.e-6, 1.e-6, GeomAbs_C1, 14, 16);
  OrtProj.SetLimit(Standard_False);
  OrtProj.Compute3d(Standard_False);
  OrtProj.Build();
  Standard_Real up1,up2;
  if ( OrtProj.IsDone()) {
    TopExp::MapShapes(OrtProj.Projection() ,TopAbs_EDGE, MapE1);
    if (MapE1.Extent()!=0) {
      TopoDS_Shape aLocalShape = TopoDS_Shape (MapE1(1));
      E1=TopoDS::Edge(aLocalShape );
//      E1=TopoDS::Edge( TopoDS_Shape (MapE1(1)));
      C2d=BRep_Tool::CurveOnSurface(E1,Face,up1,up2);
    }
  }
}

//=======================================================================
//function : ChFi3d_Recale
//purpose  :
//=======================================================================

static void ChFi3d_Recale(BRepAdaptor_Surface&   Bs,
			  gp_Pnt2d&              p1,
			  gp_Pnt2d&              p2,
			  const Standard_Boolean refon1)
{
  Handle(Geom_Surface) surf = Bs.ChangeSurface().Surface();
  Handle(Geom_RectangularTrimmedSurface)
    ts = Handle(Geom_RectangularTrimmedSurface)::DownCast(surf);
  if (!ts.IsNull()) surf = ts->BasisSurface();
  if (surf->IsUPeriodic()) {
    Standard_Real u1 = p1.X(), u2 = p2.X();
    Standard_Real uper = surf->UPeriod();
    if (fabs(u2-u1) > 0.5*uper) {
      if (u2<u1 && refon1) u2 += uper;
      else if (u2<u1 && !refon1) u1 -= uper;
      else if (u1<u2 && refon1) u2 -= uper;
      else if (u1<u2 && !refon1) u1 += uper;
    }
    p1.SetX(u1); p2.SetX(u2);
  }
  if (surf->IsVPeriodic()) {
    Standard_Real v1 = p1.Y(), v2 = p2.Y();
    Standard_Real vper = surf->VPeriod();
    if (fabs(v2-v1) > 0.5*vper) {
      if (v2<v1 && refon1) v2 += vper;
      else if (v2<v1 && !refon1) v1 -= vper;
      else if (v1<v2 && refon1) v2 -= vper;
      else if (v1<v2 && !refon1) v1 += vper;
    }
    p1.SetY(v1); p2.SetY(v2);
  }
}

//=======================================================================
//function : ChFi3d_SelectStripe
//purpose  : find stripe with ChFiDS_OnSame state if <thePrepareOnSame> is True
//=======================================================================

Standard_Boolean ChFi3d_SelectStripe(ChFiDS_ListIteratorOfListOfStripe & It,
				     const TopoDS_Vertex& Vtx,
				     const Standard_Boolean thePrepareOnSame)
{
  if (!thePrepareOnSame) return Standard_True;

  for (; It.More(); It.Next()) {
    Standard_Integer sens = 0;
    Handle(ChFiDS_Stripe) stripe = It.Value();
    ChFi3d_IndexOfSurfData(Vtx, stripe, sens);
    ChFiDS_State stat;
    if ( sens == 1 )
      stat = stripe->Spine()->FirstStatus();
    else
      stat = stripe->Spine()->LastStatus();
    if ( stat == ChFiDS_OnSame ) return Standard_True;
  }

  return Standard_False;
}
//=======================================================================
//function : PerformOneCorner
//purpose  : Calculate a corner with three edges and a fillet.
//           3 separate case: (22/07/94 only 1st is implemented)
//
//           - same concavity on three edges, intersection with the
//             face at end,
//           - concavity of 2 outgoing edges is opposite to the one of the fillet,
//             if the face at end is ready for that, the same in  case 1 on extended face,
//             otherwise a small cap is done with GeomFill,
//           - only one outgoing edge has concavity opposed to the edge of the
//             fillet and the third edge, the top of the corner is reread
//             in the empty of the fillet and closed, either by extending the face 
//             at end if it is plane and orthogonal to the
//             guiding edge, or by a cap of type GeomFill.
//
//           <thePrepareOnSame> means that only needed thing is redefinition
//           of intersection pameter of OnSame-Stripe with <Arcprol>
//           (eap, Arp 9 2002, occ266)
//=======================================================================

void ChFi3d_Builder::PerformOneCorner(const Standard_Integer Index,
				      const Standard_Boolean thePrepareOnSame)
{
  TopOpeBRepDS_DataStructure& DStr = myDS->ChangeDS();

#ifdef DEB
  OSD_Chronometer ch;// init perf for PerformSetOfKPart
#endif
  // the top,
  const TopoDS_Vertex& Vtx = myVDataMap.FindKey(Index);
  // The fillet is returned,
  ChFiDS_ListIteratorOfListOfStripe StrIt;
  StrIt.Initialize(myVDataMap(Index));
  if ( ! ChFi3d_SelectStripe (StrIt, Vtx, thePrepareOnSame)) return;
  Handle(ChFiDS_Stripe) stripe = StrIt.Value();
  const Handle(ChFiDS_Spine) spine = stripe->Spine();
  ChFiDS_SequenceOfSurfData& SeqFil =
    stripe->ChangeSetOfSurfData()->ChangeSequence();
  // SurfData and its CommonPoints,
  Standard_Integer sens = 0;

  // Choose proper SurfData
  Standard_Integer num = ChFi3d_IndexOfSurfData(Vtx,stripe,sens);
  Standard_Boolean isfirst = (sens == 1);
  if (isfirst) {
    for (; num<SeqFil.Length() && (
	 (SeqFil.Value(num)->IndexOfS1()==0) ||
	 (SeqFil.Value(num)->IndexOfS2()==0) ); ) {
      SeqFil.Remove(num); // The surplus is removed
    }
  }
  else {
   for (; num>1 && (
	 (SeqFil.Value(num)->IndexOfS1()==0) ||
	 (SeqFil.Value(num)->IndexOfS2()==0) ); ) {
     SeqFil.Remove(num);// The surplus is removed
     num--;
    }
  }

  Handle(ChFiDS_SurfData)& Fd = SeqFil.ChangeValue(num);
  ChFiDS_CommonPoint& CV1 = Fd->ChangeVertex(isfirst,1);
  ChFiDS_CommonPoint& CV2 = Fd->ChangeVertex(isfirst,2);
  //To evaluate the new points.
  Bnd_Box box1,box2;

  // The cases of cap and intersection are processed separately.
  // ----------------------------------------------------------
  ChFiDS_State stat;
  if (isfirst) stat = spine->FirstStatus();
  else         stat = spine->LastStatus();
  Standard_Boolean onsame = (stat == ChFiDS_OnSame);
  TopoDS_Face Fv,Fad,Fop;
  TopoDS_Edge Arcpiv,Arcprol,Arcspine;
  if (isfirst) Arcspine = spine->Edges(1);
  else         Arcspine = spine->Edges(spine->NbEdges());
#ifndef DEB
  TopAbs_Orientation OArcprolv = TopAbs_FORWARD, OArcprolop = TopAbs_FORWARD;
#else
  TopAbs_Orientation OArcprolv,OArcprolop;
#endif
  Standard_Integer ICurve;
  Handle(BRepAdaptor_HSurface) HBs  = new BRepAdaptor_HSurface();
  Handle(BRepAdaptor_HSurface) HBad = new BRepAdaptor_HSurface();
  Handle(BRepAdaptor_HSurface) HBop = new BRepAdaptor_HSurface();
  BRepAdaptor_Surface& Bs  = HBs->ChangeSurface();
  BRepAdaptor_Surface& Bad = HBad->ChangeSurface();
  BRepAdaptor_Surface& Bop = HBop->ChangeSurface();
  Handle(Geom_Curve) Cc;
  Handle(Geom2d_Curve) Pc,Ps;
  Standard_Real Ubid,Vbid;//,mu,Mu,mv,Mv;
#ifndef DEB
  Standard_Real Udeb = 0.,Ufin = 0.;
#else
  Standard_Real Udeb,Ufin;
#endif
//  gp_Pnt2d UVf1,UVl1,UVf2,UVl2;
//  Standard_Real Du,Dv,Step;
  Standard_Boolean inters = Standard_True;
  Standard_Integer IFadArc = 1, IFopArc = 2;
  Fop = TopoDS::Face(DStr.Shape(Fd->Index(IFopArc)));
  TopExp_Explorer ex;

#ifdef DEB
  ChFi3d_InitChron(ch); // init perf condition  if (onsame)
#endif

  if (onsame) {
    if (!CV1.IsOnArc() && !CV2.IsOnArc())
      Standard_Failure::Raise("Corner OnSame : no point on arc");
    else if (CV1.IsOnArc() && CV2.IsOnArc()) {
       Standard_Boolean sur1 = 0, sur2 = 0;
      for(ex.Init(CV1.Arc(),TopAbs_VERTEX); ex.More(); ex.Next()) {
	if (Vtx.IsSame(ex.Current())) {
	  sur1 = 1;
	  break;
	}
      }
      for(ex.Init(CV2.Arc(),TopAbs_VERTEX); ex.More(); ex.Next()) {
	if (Vtx.IsSame(ex.Current())) {
	  sur2 = 1;
	  break;
	}
      }
      if (sur1 && sur2) {
	TopoDS_Edge E[3];
	E[0] = CV1.Arc(); E[1] = CV2.Arc(); E[2] = Arcspine;
	if (ChFi3d_EdgeState(E,myEFMap) != ChFiDS_OnDiff) IFadArc = 2;
      }
      else if (sur2) IFadArc = 2;
    }
    else if (CV2.IsOnArc()) IFadArc = 2;
    IFopArc = 3-IFadArc;

    Arcpiv = Fd->Vertex(isfirst,IFadArc).Arc();
    Fad = TopoDS::Face(DStr.Shape(Fd->Index(IFadArc)));
    Fop = TopoDS::Face(DStr.Shape(Fd->Index(IFopArc)));
    TopTools_ListIteratorOfListOfShape It;
    // The face at end is returned without check of its unicity.
    for(It.Initialize(myEFMap(Arcpiv));It.More();It.Next()) {
      if (!Fad.IsSame(It.Value())) {
	Fv = TopoDS::Face(It.Value());
	break;
      }
    }

    // Does the face at bout contain the Vertex ?
    Standard_Boolean isinface = Standard_False;
    for (ex.Init(Fv,TopAbs_VERTEX); ex.More(); ex.Next()) {
      if (ex.Current().IsSame(Vtx)) {
	isinface = Standard_True;
	break;
      }
    }
    if (!isinface && Fd->Vertex(isfirst,3-IFadArc).IsOnArc()) {
      IFadArc = 3-IFadArc;
      IFopArc = 3-IFopArc;
      Arcpiv = Fd->Vertex(isfirst,IFadArc).Arc();
      Fad = TopoDS::Face(DStr.Shape(Fd->Index(IFadArc)));
      Fop = TopoDS::Face(DStr.Shape(Fd->Index(IFopArc)));
      //TopTools_ListIteratorOfListOfShape It;
     // The face at end is returned without check of its unicity.
      for(It.Initialize(myEFMap(Arcpiv));It.More();It.Next()) {
	if (!Fad.IsSame(It.Value())) {
	  Fv = TopoDS::Face(It.Value());
	  break;
	}
      }
    }

    if (Fv.IsNull()) StdFail_NotDone::Raise
      ("OneCorner : face at end not found");

    Fv.Orientation(TopAbs_FORWARD);
    Fad.Orientation(TopAbs_FORWARD);
    Fop.Orientation(TopAbs_FORWARD);

    // The edge that will be extended is returned.
    for(It.Initialize(myVEMap(Vtx));It.More() && Arcprol.IsNull();It.Next()) {
      if (!Arcpiv.IsSame(It.Value())) {
	for(ex.Init(Fv,TopAbs_EDGE); ex.More(); ex.Next()) {
	  if (It.Value().IsSame(ex.Current())) {
	    Arcprol = TopoDS::Edge(It.Value());
	    OArcprolv = ex.Current().Orientation();
	    break;
	  }
	}
      }
    }
    if (Arcprol.IsNull()) /*StdFail_NotDone::Raise
      ("OneCorner : edge a prolonger non trouve");*/
    {
      PerformIntersectionAtEnd(Index);
      return;
    }
    for(ex.Init(Fop,TopAbs_EDGE); ex.More(); ex.Next()) {
      if (Arcprol.IsSame(ex.Current())) {
	OArcprolop = ex.Current().Orientation();
	break;
      }
    }
    TopoDS_Face FFv;
    Standard_Real tol;
    Standard_Integer prol=0;
    BRep_Builder BRE;
    Handle(Geom_Surface ) Sface;
    Sface=BRep_Tool::Surface(Fv);
    ChFi3d_ExtendSurface(Sface,prol);
    tol=BRep_Tool::Tolerance(Fv);
    BRE.MakeFace(FFv,Sface,tol);
    if (prol) {
      Bs.Initialize(FFv,Standard_False);
      DStr.SetNewSurface(Fv,Sface);
    }
    else Bs.Initialize(Fv,Standard_False);
    Bad.Initialize(Fad);
    Bop.Initialize(Fop);
  }
  //in case of OnSame it is necessary to modify the CommonPoint
  //in the empty and its parameter in the FaceInterference.
  //They are both returned in non const references. Attention the modifications are done behind
  //de CV1,CV2,Fi1,Fi2.
  ChFiDS_CommonPoint& CPopArc = Fd->ChangeVertex(isfirst,IFopArc);
  ChFiDS_FaceInterference& FiopArc = Fd->ChangeInterference(IFopArc);
  ChFiDS_CommonPoint& CPadArc = Fd->ChangeVertex(isfirst,IFadArc);
  ChFiDS_FaceInterference& FiadArc = Fd->ChangeInterference(IFadArc);
  //the parameter of the vertex in the air is initialiced with the value of 
  //its opposite (point on arc).
  Standard_Real wop = Fd->ChangeInterference(IFadArc).Parameter(isfirst);
  Handle(Geom_Curve) c3df;
  Handle(GeomAdaptor_HSurface)
    HGs = new GeomAdaptor_HSurface(DStr.Surface(Fd->Surf()).Surface());
  gp_Pnt2d p2dbout;

  if (onsame) {

    ChFiDS_CommonPoint saveCPopArc = CPopArc;
    c3df = DStr.Curve(FiopArc.LineIndex()).Curve();

    inters = IntersUpdateOnSame (HGs,HBs,c3df,Fop,Fv,Arcprol,Vtx,isfirst,10*tolesp, // in
				 FiopArc,CPopArc,p2dbout,wop);   // out

    Handle(BRepAdaptor_HCurve2d) pced = new BRepAdaptor_HCurve2d();
    pced->ChangeCurve2d().Initialize(CPadArc.Arc(),Fv);
    // in the case of degenerated Fi, parameter difference can be even negative (eap, occ293)
    if ((FiadArc.LastParameter() - FiadArc.FirstParameter()) > 10*tolesp)
      Update(HBs,pced,HGs,FiadArc,CPadArc,isfirst);

    if (thePrepareOnSame) {
      //saveCPopArc.SetParameter(wop);
      saveCPopArc.SetPoint(CPopArc.Point());
      CPopArc = saveCPopArc;
      return;
    }
  }
  else {
    inters = FindFace(Vtx,CV1,CV2,Fv,Fop);
    if (!inters) {
      PerformIntersectionAtEnd(Index);
      return;
    }
    Bs.Initialize(Fv);
    Handle(BRepAdaptor_HCurve2d) pced = new BRepAdaptor_HCurve2d();
    pced->ChangeCurve2d().Initialize(CV1.Arc(),Fv);
    Update(HBs,pced,HGs,Fd->ChangeInterferenceOnS1(),CV1,isfirst);
    pced->ChangeCurve2d().Initialize(CV2.Arc(),Fv);
    Update(HBs,pced,HGs,Fd->ChangeInterferenceOnS2(),CV2,isfirst);
  }


#ifdef DEB
 ChFi3d_ResultChron(ch,t_same); // result perf condition if (same)
 ChFi3d_InitChron(ch); // init perf condition if (inters)
#endif

  TopoDS_Edge edgecouture;
  Standard_Boolean couture,intcouture=Standard_False;;
  Standard_Real tolreached = 0.0;
#ifndef DEB
  Standard_Real  par1 =0.,par2 =0.;
  Standard_Integer indpt = 0,Icurv1 = 0,Icurv2 = 0;
#else
  Standard_Real  par1,par2;
  Standard_Integer indpt,Icurv1,Icurv2;
#endif
  Handle(Geom_TrimmedCurve) curv1,curv2;
  Handle(Geom2d_Curve) c2d1,c2d2;

  Standard_Integer Isurf=Fd->Surf();

  if (inters) {
    HGs = ChFi3d_BoundSurf(DStr,Fd,1,2);
    const ChFiDS_FaceInterference& Fi1 = Fd->InterferenceOnS1();
    const ChFiDS_FaceInterference& Fi2 = Fd->InterferenceOnS2();
    TColStd_Array1OfReal Pardeb(1,4),Parfin(1,4);
    gp_Pnt2d pfil1,pfac1,pfil2,pfac2;
    Handle(Geom2d_Curve) Hc1,Hc2;
    if (onsame && IFopArc == 1) pfac1 = p2dbout;
    else {
      Hc1 = BRep_Tool::CurveOnSurface(CV1.Arc(),Fv,Ubid,Ubid);
      pfac1 = Hc1->Value(CV1.ParameterOnArc());
    }
    if (onsame && IFopArc == 2) pfac2 = p2dbout;
    else {
      Hc2 = BRep_Tool::CurveOnSurface(CV2.Arc(),Fv,Ubid,Ubid);
      pfac2 = Hc2->Value(CV2.ParameterOnArc());
    }
    if (Fi1.LineIndex() != 0) {
      pfil1 = Fi1.PCurveOnSurf()->Value(Fi1.Parameter(isfirst));
    }
    else {
      pfil1 = Fi1.PCurveOnSurf()->Value(Fi1.Parameter(!isfirst));
    }
    if (Fi2.LineIndex() != 0) {
      pfil2 = Fi2.PCurveOnSurf()->Value(Fi2.Parameter(isfirst));
    }
    else {
      pfil2 = Fi2.PCurveOnSurf()->Value(Fi2.Parameter(!isfirst));
    }
    if (onsame) ChFi3d_Recale(Bs,pfac1,pfac2,(IFadArc == 1));

    Pardeb(1)= pfil1.X(); Pardeb(2) = pfil1.Y();
    Pardeb(3)= pfac1.X(); Pardeb(4) = pfac1.Y();
    Parfin(1)= pfil2.X(); Parfin(2) = pfil2.Y();
    Parfin(3)= pfac2.X(); Parfin(4) = pfac2.Y();

    Standard_Real uu1,uu2,vv1,vv2;
    ChFi3d_Boite(pfac1,pfac2,uu1,uu2,vv1,vv2);
    ChFi3d_BoundFac(Bs,uu1,uu2,vv1,vv2);

    if (!ChFi3d_ComputeCurves(HGs,HBs,Pardeb,Parfin,Cc,
			      Ps,
			      Pc,tolesp,tol2d,tolreached))
      Standard_Failure::Raise("OneCorner : echec calcul intersection");

    Udeb = Cc->FirstParameter();
    Ufin = Cc->LastParameter();

    //  determine if the curve has an intersection with edge of sewing

    ChFi3d_Couture(Fv,couture,edgecouture);

    if (couture  && !BRep_Tool::Degenerated(edgecouture)) {

      //Standard_Real Ubid,Vbid;
      Handle (Geom_Curve) C=BRep_Tool::Curve(edgecouture,Ubid,Vbid);
      Handle(Geom_TrimmedCurve) Ctrim=new Geom_TrimmedCurve (C,Ubid,Vbid);
      GeomAdaptor_Curve cur1(Ctrim->BasisCurve());
      GeomAdaptor_Curve cur2(Cc);
      Extrema_ExtCC extCC (cur1,cur2);
      if (extCC.IsDone()&&extCC.NbExt()!=0)
      {
        Standard_Integer imin=0;
        Standard_Real distmin2 = RealLast();
        for (Standard_Integer i = 1; i <= extCC.NbExt(); i++)
          if (extCC.SquareDistance(i) < distmin2)
          {
            distmin2 = extCC.SquareDistance(i);
            imin = i;
          }
        if (distmin2 <= Precision::Confusion() * Precision::Confusion())
        {
          Extrema_POnCurv ponc1,ponc2;
          extCC.Points( imin, ponc1, ponc2 );
          par1 = ponc1.Parameter();
          par2 = ponc2.Parameter();
          Standard_Real Tol = 1.e-4;
          if (Abs(par2-Udeb) > Tol && Abs(Ufin-par2) > Tol)
          {
            gp_Pnt P1 = ponc1.Value();
            TopOpeBRepDS_Point tpoint( P1, Tol );
            indpt = DStr.AddPoint(tpoint);
            intcouture = Standard_True;
            curv1 = new Geom_TrimmedCurve(Cc,Udeb,par2);
            curv2 = new Geom_TrimmedCurve(Cc,par2,Ufin);
            TopOpeBRepDS_Curve tcurv1(curv1,tolreached);
            TopOpeBRepDS_Curve tcurv2(curv2,tolreached);
            Icurv1=DStr.AddCurve(tcurv1);
            Icurv2=DStr.AddCurve(tcurv2);
          }
        }
      }
    }
  }
  else { // (!inters)
    Standard_NotImplemented::Raise("OneCorner : bouchon non ecrit");
  }
  Standard_Integer IShape = DStr.AddShape(Fv);
#ifndef DEB
  TopAbs_Orientation Et = TopAbs_FORWARD;
#else
  TopAbs_Orientation Et;
#endif
  if (IFadArc == 1) {
    TopExp_Explorer Exp;
    for (Exp.Init(Fv.Oriented(TopAbs_FORWARD),
		  TopAbs_EDGE);Exp.More();Exp.Next()) {
      if (Exp.Current().IsSame(CV1.Arc())) {
	Et = TopAbs::Reverse(TopAbs::Compose
			     (Exp.Current().Orientation(),
			      CV1.TransitionOnArc()));
	break;
      }
    }
  }
  else {
    TopExp_Explorer Exp;
    for (Exp.Init(Fv.Oriented(TopAbs_FORWARD),
			      TopAbs_EDGE);Exp.More();Exp.Next()) {
      if (Exp.Current().IsSame(CV2.Arc())) {
	Et = TopAbs::Compose(Exp.Current().Orientation(),
			     CV2.TransitionOnArc());
	break;
      }
    }

//


  }

#ifdef DEB
  ChFi3d_ResultChron(ch ,t_inter); //result perf condition if (inter)
  ChFi3d_InitChron(ch); // init perf condition  if (onsame && inters)
#endif

  stripe->SetIndexPoint(ChFi3d_IndexPointInDS(CV1,DStr),isfirst,1);
  stripe->SetIndexPoint(ChFi3d_IndexPointInDS(CV2,DStr),isfirst,2);

  if (!intcouture) {
// there is no intersection with the sewing edge
// the curve Cc is stored in the stripe
// the storage in the DS is not done by FILDS.

    TopOpeBRepDS_Curve Tc(Cc,tolreached);
    ICurve = DStr.AddCurve(Tc);
    Handle(TopOpeBRepDS_SurfaceCurveInterference)
      Interfc = ChFi3d_FilCurveInDS(ICurve,IShape,Pc,Et);

    // 31/01/02 akm vvv : (OCC119) Prevent the builder from creating
    //                    intersecting fillets - they are bad.
    Geom2dInt_GInter anIntersector;
    Geom2dAdaptor_Curve aCorkPCurve (Pc, Udeb, Ufin);

    // Take all the interferences with faces from all the stripes
    // and look if their pcurves intersect our cork pcurve.
    // Unfortunately, by this moment they do not exist in DStr.
    ChFiDS_ListIteratorOfListOfStripe aStrIt(myListStripe);
    for (; aStrIt.More(); aStrIt.Next())
    {
      Handle(ChFiDS_Stripe) aCheckStripe = aStrIt.Value();
      Handle(ChFiDS_HData) aSeqData = aCheckStripe->SetOfSurfData();
      // Loop on parts of the stripe
      Standard_Integer iPart;
      for (iPart=1; iPart<=aSeqData->Length(); iPart++)
      {
	Handle(ChFiDS_SurfData) aData = aSeqData->Value(iPart);
	Geom2dAdaptor_Curve anOtherPCurve;
	if (IShape == aData->IndexOfS1())
	{
	  anOtherPCurve.Load (aData->InterferenceOnS1().PCurveOnFace(),
			      aData->InterferenceOnS1().FirstParameter(),
			      aData->InterferenceOnS1().LastParameter());
	}
	else if (IShape == aData->IndexOfS2())
	{
	  anOtherPCurve.Load (aData->InterferenceOnS2().PCurveOnFace(),
			      aData->InterferenceOnS2().FirstParameter(),
			      aData->InterferenceOnS2().LastParameter());
	}
	else
	{
	  // Normal case - no common surface
	  continue;
	}
	if (IsEqual(anOtherPCurve.LastParameter(),anOtherPCurve.FirstParameter()))
	  // Degenerates
	  continue;
	anIntersector.Perform (aCorkPCurve, anOtherPCurve,
			       tol2d, Precision::PConfusion());
	if (anIntersector.NbSegments() > 0 ||
	    anIntersector.NbPoints() > 0)
	  StdFail_NotDone::Raise ("OneCorner : fillets have too big radiuses");
      }
    }
    TopOpeBRepDS_ListIteratorOfListOfInterference
      anIter(DStr.ChangeShapeInterferences(IShape));
    for (; anIter.More(); anIter.Next())
    {
      Handle(TopOpeBRepDS_SurfaceCurveInterference) anOtherIntrf =
	Handle(TopOpeBRepDS_SurfaceCurveInterference)::DownCast(anIter.Value());
      // We need only interferences between cork face and curves
      // of intersection with another fillet surfaces
      if (anOtherIntrf.IsNull())
	continue;
      // Look if there is an intersection between pcurves
      Handle(Geom_TrimmedCurve) anOtherCur =
	Handle(Geom_TrimmedCurve)::DownCast(DStr.Curve (anOtherIntrf->Geometry()).Curve());
      if (anOtherCur.IsNull())
	continue;
      Geom2dAdaptor_Curve anOtherPCurve (anOtherIntrf->PCurve(),
					 anOtherCur->FirstParameter(),
					 anOtherCur->LastParameter());
      anIntersector.Perform (aCorkPCurve, anOtherPCurve,
			     tol2d, Precision::PConfusion());
      if (anIntersector.NbSegments() > 0 ||
	  anIntersector.NbPoints() > 0)
	StdFail_NotDone::Raise ("OneCorner : fillets have too big radiuses");
    }
    // 31/01/02 akm ^^^
    DStr.ChangeShapeInterferences(IShape).Append(Interfc);
    //// modified by jgv, 26.03.02 for OCC32 ////
    ChFiDS_CommonPoint CV [2];
    CV[0] = CV1;
    CV[1] = CV2;
    for (Standard_Integer i = 0; i < 2; i++)
    {
      if (CV[i].IsOnArc() && ChFi3d_IsPseudoSeam( CV[i].Arc(), Fv ))
      {
        gp_Pnt2d pfac1, PcF, PcL;
        gp_Vec2d DerPc, DerHc;
        Standard_Real first, last, prm1, prm2;
        Standard_Boolean onfirst, FirstToPar;
        Handle(Geom2d_Curve) Hc = BRep_Tool::CurveOnSurface( CV[i].Arc(), Fv, first, last );
        pfac1 = Hc->Value( CV[i].ParameterOnArc() );
        PcF = Pc->Value( Udeb );
        PcL = Pc->Value( Ufin );
        onfirst = (pfac1.Distance(PcF) < pfac1.Distance(PcL))? Standard_True : Standard_False;
        if (onfirst)
          Pc->D1( Udeb, PcF, DerPc );
        else
        {
          Pc->D1( Ufin, PcL, DerPc );
          DerPc.Reverse();
        }
        Hc->D1( CV[i].ParameterOnArc(), pfac1, DerHc );
        if (DerHc.Dot(DerPc) > 0.)
        {
          prm1 = CV[i].ParameterOnArc();
          prm2 = last;
          FirstToPar = Standard_False;
        }
        else
        {
          prm1 = first;
          prm2 = CV[i].ParameterOnArc();
          FirstToPar = Standard_True;
        }
        Handle(Geom_Curve) Ct = BRep_Tool::Curve( CV[i].Arc(), first, last );
        Ct = new Geom_TrimmedCurve( Ct, prm1, prm2 );
        Standard_Real toled = BRep_Tool::Tolerance( CV[i].Arc() );
        TopOpeBRepDS_Curve tcurv( Ct, toled );
        Handle (TopOpeBRepDS_CurvePointInterference) Interfp1, Interfp2;
        Standard_Integer indcurv;
        indcurv = DStr.AddCurve( tcurv );
        Standard_Integer indpoint = (isfirst)? stripe->IndexFirstPointOnS1() : stripe->IndexLastPointOnS1();
        Standard_Integer indvertex = DStr.AddShape(Vtx);
        if (FirstToPar)
        {
          Interfp1 = ChFi3d_FilPointInDS( TopAbs_FORWARD,  indcurv, indvertex, prm1, Standard_True );
          Interfp2 = ChFi3d_FilPointInDS( TopAbs_REVERSED, indcurv, indpoint,  prm2, Standard_False );
        }
        else
        {
          Interfp1 = ChFi3d_FilPointInDS( TopAbs_FORWARD,  indcurv, indpoint,  prm1, Standard_False );
          Interfp2 = ChFi3d_FilPointInDS( TopAbs_REVERSED, indcurv, indvertex, prm2, Standard_True );
        }
        DStr.ChangeCurveInterferences(indcurv).Append(Interfp1);
        DStr.ChangeCurveInterferences(indcurv).Append(Interfp2);
        Standard_Integer indface = DStr.AddShape( Fv );
        Interfc = ChFi3d_FilCurveInDS( indcurv, indface, Hc, CV[i].Arc().Orientation() );
        DStr.ChangeShapeInterferences(indface).Append( Interfc );
        TopoDS_Edge aLocalEdge = CV[i].Arc();
        aLocalEdge.Reverse();
        Handle(Geom2d_Curve) HcR = BRep_Tool::CurveOnSurface( aLocalEdge, Fv, first, last );
        Interfc = ChFi3d_FilCurveInDS( indcurv, indface, HcR, aLocalEdge.Orientation() );
        DStr.ChangeShapeInterferences(indface).Append( Interfc );
        //modify degenerated edge
        Standard_Boolean DegenExist = Standard_False;
        TopoDS_Edge Edeg;
        TopExp_Explorer Explo( Fv, TopAbs_EDGE );
        for (; Explo.More(); Explo.Next())
        {
          const TopoDS_Edge& Ecur = TopoDS::Edge( Explo.Current() );
          if (BRep_Tool::Degenerated( Ecur ))
          {
            TopoDS_Vertex Vf, Vl;
            TopExp::Vertices( Ecur, Vf, Vl );
            if (Vf.IsSame(Vtx) || Vl.IsSame(Vtx))
            {
              DegenExist = Standard_True;
              Edeg = Ecur;
              break;
            }
          }
        }
        if (DegenExist)
        {
          Standard_Real fd, ld;
          Handle(Geom2d_Curve) Cd = BRep_Tool::CurveOnSurface( Edeg, Fv, fd, ld );
          Handle(Geom2d_TrimmedCurve) tCd = Handle(Geom2d_TrimmedCurve)::DownCast(Cd);
          if (! tCd.IsNull())
            Cd = tCd->BasisCurve();
          gp_Pnt2d P2d = (FirstToPar)? Hc->Value(first) : Hc->Value(last);
          Geom2dAPI_ProjectPointOnCurve Projector( P2d, Cd );
          Standard_Real par = Projector.LowerDistanceParameter();
          Standard_Integer Ideg = DStr.AddShape(Edeg);
          TopAbs_Orientation ori = (par < fd)? TopAbs_FORWARD : TopAbs_REVERSED; //if par<fd => par>ld
          Interfp1 = ChFi3d_FilPointInDS( ori, Ideg, indvertex, par, Standard_True );
          DStr.ChangeShapeInterferences(Ideg).Append(Interfp1);
        }
      }
    }
    /////////////////////////////////////////////
    stripe->ChangePCurve(isfirst)=Ps;
    stripe->SetCurve(ICurve,isfirst);
    stripe->SetParameters(isfirst,Udeb,Ufin);
  }
  else {
// curves curv1 are curv2 stored in the DS
// these curves will not be reconstructed by FILDS as
// one places stripe->InDS(isfirst);

    // interferences of curv1 and curv2 on Fv
    ComputeCurve2d(curv1,Fv,c2d1);
    Handle(TopOpeBRepDS_SurfaceCurveInterference) InterFv;
    InterFv = ChFi3d_FilCurveInDS(Icurv1,IShape,c2d1,Et);
    DStr.ChangeShapeInterferences(IShape).Append(InterFv);
    ComputeCurve2d(curv2,Fv,c2d2);
    InterFv = ChFi3d_FilCurveInDS(Icurv2,IShape,c2d2,Et);
    DStr.ChangeShapeInterferences(IShape).Append(InterFv);
     // interferences of curv1 and curv2 on Isurf
    if (Fd->Orientation()== Fv.Orientation()) Et=TopAbs::Reverse(Et);
    c2d1=new Geom2d_TrimmedCurve(Ps,Udeb,par2);
    InterFv = ChFi3d_FilCurveInDS(Icurv1,Isurf,c2d1,Et);
    DStr.ChangeSurfaceInterferences(Isurf).Append(InterFv);
    c2d2=new Geom2d_TrimmedCurve(Ps,par2,Ufin);
       InterFv = ChFi3d_FilCurveInDS(Icurv2,Isurf,c2d2,Et);
    DStr.ChangeSurfaceInterferences(Isurf).Append(InterFv);

      // limitation of the sewing edge
    Standard_Integer Iarc=DStr.AddShape(edgecouture);
    Handle(TopOpeBRepDS_CurvePointInterference) Interfedge;
    TopAbs_Orientation ori;
    TopoDS_Vertex Vdeb,Vfin;
    Vdeb=TopExp::FirstVertex(edgecouture);
    Vfin=TopExp::LastVertex(edgecouture);
    Standard_Real pard,parf;
    pard=BRep_Tool::Parameter(Vdeb,edgecouture);
    parf=BRep_Tool::Parameter(Vfin,edgecouture);
    if (Abs(par1-pard)<Abs(parf-par1)) ori=TopAbs_FORWARD;
    else ori=TopAbs_REVERSED;
    Interfedge = ChFi3d_FilPointInDS(ori,Iarc,indpt,par1);
    DStr.ChangeShapeInterferences(Iarc).Append(Interfedge);

    // creation of CurveInterferences from Icurv1 and Icurv2
    stripe->InDS(isfirst);
    Standard_Integer ind1= stripe->IndexPoint(isfirst,1);
    Standard_Integer ind2= stripe->IndexPoint(isfirst,2);
    Handle(TopOpeBRepDS_CurvePointInterference)
      interfprol = ChFi3d_FilPointInDS(TopAbs_FORWARD,Icurv1,ind1,Udeb);
    DStr.ChangeCurveInterferences(Icurv1).Append(interfprol);
    interfprol = ChFi3d_FilPointInDS(TopAbs_REVERSED,Icurv1,indpt,par2);
    DStr.ChangeCurveInterferences(Icurv1).Append(interfprol);
    interfprol = ChFi3d_FilPointInDS(TopAbs_FORWARD,Icurv2,indpt,par2);
    DStr.ChangeCurveInterferences(Icurv2).Append(interfprol);
    interfprol = ChFi3d_FilPointInDS(TopAbs_REVERSED,Icurv2,ind2,Ufin);
    DStr.ChangeCurveInterferences(Icurv2).Append(interfprol);

  }

  ChFi3d_EnlargeBox(HBs,Pc,Udeb,Ufin,box1,box2);

  if (onsame && inters) {
    // VARIANT 1:
    // A small missing end of curve is added for the extension
    // of the face at end and the limitation of the opposing face.

    //   VARIANT 2 : extend Arcprol, not create new small edge
    //   To do: modify for intcouture
    const Standard_Boolean variant1 = Standard_True;

    // First of all the ponts are cut with the edge of the spine.
    Standard_Integer IArcspine = DStr.AddShape(Arcspine);
    Standard_Integer IVtx = DStr.AddShape(Vtx);
#ifndef DEB
    TopAbs_Orientation OVtx = TopAbs_FORWARD;
#else
    TopAbs_Orientation OVtx;
#endif
    for(ex.Init(Arcspine.Oriented(TopAbs_FORWARD),TopAbs_VERTEX);
	ex.More(); ex.Next()) {
      if (Vtx.IsSame(ex.Current())) {
	OVtx = ex.Current().Orientation();
	break;
      }
    }
    OVtx = TopAbs::Reverse(OVtx);
    Standard_Real parVtx = BRep_Tool::Parameter(Vtx,Arcspine);
    Handle(TopOpeBRepDS_CurvePointInterference)
      interfv = ChFi3d_FilVertexInDS(OVtx,IArcspine,IVtx,parVtx);
    DStr.ChangeShapeInterferences(IArcspine).Append(interfv);

    // Now the missing curves are constructed.
    TopoDS_Vertex V2;
    for(ex.Init(Arcprol.Oriented(TopAbs_FORWARD),TopAbs_VERTEX);
	ex.More(); ex.Next()) {
      if (Vtx.IsSame(ex.Current()))
	OVtx = ex.Current().Orientation();
      else
	V2 =  TopoDS::Vertex(ex.Current());
    }

    Handle(Geom2d_Curve) Hc;
    if (variant1)
      parVtx = BRep_Tool::Parameter(Vtx,Arcprol);
    else
      parVtx = BRep_Tool::Parameter(V2,Arcprol);
    const ChFiDS_FaceInterference& Fiop = Fd->Interference(IFopArc);
    gp_Pnt2d pop1, pop2, pv1, pv2;
    Hc = BRep_Tool::CurveOnSurface(Arcprol,Fop,Ubid,Ubid);
    pop1 = Hc->Value(parVtx);
    pop2 = Fiop.PCurveOnFace()->Value(Fiop.Parameter(isfirst));
    Hc = BRep_Tool::CurveOnSurface(Arcprol,Fv,Ubid,Ubid);
    pv1 = Hc->Value(parVtx);
    pv2 = p2dbout;
    ChFi3d_Recale(Bs,pv1,pv2,1);
    TColStd_Array1OfReal Pardeb(1,4),Parfin(1,4);
    Pardeb(1) = pop1.X(); Pardeb(2) = pop1.Y();
    Pardeb(3) = pv1.X();  Pardeb(4) = pv1.Y();
    Parfin(1) = pop2.X(); Parfin(2) = pop2.Y();
    Parfin(3) = pv2.X();  Parfin(4) = pv2.Y();
    Standard_Real uu1,uu2,vv1,vv2;
    ChFi3d_Boite(pv1,pv2,uu1,uu2,vv1,vv2);
    ChFi3d_BoundFac(Bs,uu1,uu2,vv1,vv2);
    ChFi3d_Boite(pop1,pop2,uu1,uu2,vv1,vv2);
    ChFi3d_BoundFac(Bop,uu1,uu2,vv1,vv2);

    Handle(Geom_Curve) zob3d;
    Handle(Geom2d_Curve) zob2dop, zob2dv;
    //Standard_Real tolreached;
    if (!ChFi3d_ComputeCurves(HBop,HBs,Pardeb,Parfin,zob3d,zob2dop,
			      zob2dv,tolesp,tol2d,tolreached))
      Standard_Failure::Raise("OneCorner : echec calcul intersection");

    Udeb = zob3d->FirstParameter();
    Ufin = zob3d->LastParameter();
    TopOpeBRepDS_Curve Zob(zob3d,tolreached);
    Standard_Integer IZob = DStr.AddCurve(Zob);

// it is determined if Fop has an edge of sewing 
// it is determined if the curve has an intersection with the edge of sewing

    //TopoDS_Edge edgecouture;
    //Standard_Boolean couture;
    ChFi3d_Couture(Fop,couture,edgecouture);

    if (couture  && !BRep_Tool::Degenerated(edgecouture)) {
      BRepLib_MakeEdge Bedge (zob3d);
      TopoDS_Edge edg =Bedge. Edge();
      BRepExtrema_ExtCC extCC (edgecouture,edg);
      if (extCC.IsDone()&&extCC.NbExt()!=0) {
        for (Standard_Integer i=1; i<=extCC.NbExt()&&!intcouture;i++) {
	  if (extCC.SquareDistance(i)<=1.e-8) {
	    par1=extCC.ParameterOnE1(i);
	    par2=extCC.ParameterOnE2(i);
	    gp_Pnt P1=extCC.PointOnE1(i);
	    TopOpeBRepDS_Point tpoint(P1,1.e-4);
	    indpt=DStr.AddPoint(tpoint);
	    intcouture=Standard_True;
	    curv1 = new Geom_TrimmedCurve(zob3d,Udeb,par2);
	    curv2 = new Geom_TrimmedCurve(zob3d,par2,Ufin);
	    TopOpeBRepDS_Curve tcurv1(curv1,tolreached);
	    TopOpeBRepDS_Curve tcurv2(curv2,tolreached);
	    Icurv1=DStr.AddCurve(tcurv1);
	    Icurv2=DStr.AddCurve(tcurv2);
	  }
	}
      }
    }
    if (intcouture) {

// interference of curv1 and curv2 on Ishape
      Et = TopAbs::Reverse(TopAbs::Compose(OVtx,OArcprolv));
      ComputeCurve2d(curv1,Fop,c2d1);
      Handle(TopOpeBRepDS_SurfaceCurveInterference)
	InterFv = ChFi3d_FilCurveInDS(Icurv1,IShape,/*zob2dv*/c2d1,Et);
      DStr.ChangeShapeInterferences(IShape).Append(InterFv);
      ComputeCurve2d(curv2,Fop,c2d2);
      InterFv = ChFi3d_FilCurveInDS(Icurv2,IShape,/*zob2dv*/c2d2,Et);
      DStr.ChangeShapeInterferences(IShape).Append(InterFv);

      // limitation of the sewing edge
      Standard_Integer Iarc=DStr.AddShape(edgecouture);
      Handle(TopOpeBRepDS_CurvePointInterference) Interfedge;
      TopAbs_Orientation ori;
      TopoDS_Vertex Vdeb,Vfin;
      Vdeb=TopExp::FirstVertex(edgecouture);
      Vfin=TopExp::LastVertex(edgecouture);
      Standard_Real pard,parf;
      pard=BRep_Tool::Parameter(Vdeb,edgecouture);
      parf=BRep_Tool::Parameter(Vfin,edgecouture);
      if (Abs(par1-pard)<Abs(parf-par1)) ori=TopAbs_REVERSED;
      else ori=TopAbs_FORWARD;
      Interfedge = ChFi3d_FilPointInDS(ori,Iarc,indpt,par1);
      DStr.ChangeShapeInterferences(Iarc).Append(Interfedge);

    //  interference of curv1 and curv2 on Iop
      Standard_Integer Iop = DStr.AddShape(Fop);
      Et = TopAbs::Reverse(TopAbs::Compose(OVtx,OArcprolop));
      Handle(TopOpeBRepDS_SurfaceCurveInterference)  Interfop;
      ComputeCurve2d(curv1,Fop,c2d1);
      Interfop  = ChFi3d_FilCurveInDS(Icurv1,Iop,c2d1,Et);
      DStr.ChangeShapeInterferences(Iop).Append(Interfop);
      ComputeCurve2d(curv2,Fop,c2d2);
      Interfop  = ChFi3d_FilCurveInDS(Icurv2,Iop,c2d2,Et);
      DStr.ChangeShapeInterferences(Iop).Append(Interfop);
      Handle(TopOpeBRepDS_CurvePointInterference)
	interfprol = ChFi3d_FilVertexInDS(TopAbs_FORWARD,Icurv1,IVtx,Udeb);
      DStr.ChangeCurveInterferences(Icurv1).Append(interfprol);
      interfprol = ChFi3d_FilPointInDS(TopAbs_REVERSED,Icurv1,indpt,par2);
      DStr.ChangeCurveInterferences(Icurv1).Append(interfprol);
      Standard_Integer icc = stripe->IndexPoint(isfirst,IFopArc);
      interfprol = ChFi3d_FilPointInDS(TopAbs_FORWARD,Icurv2,indpt,par2);
      DStr.ChangeCurveInterferences(Icurv2).Append(interfprol);
      interfprol = ChFi3d_FilPointInDS(TopAbs_REVERSED,Icurv2,icc,Ufin);
      DStr.ChangeCurveInterferences(Icurv2).Append(interfprol);
    }
    else {
      Et = TopAbs::Reverse(TopAbs::Compose(OVtx,OArcprolv));
      Handle(TopOpeBRepDS_SurfaceCurveInterference)
	InterFv = ChFi3d_FilCurveInDS(IZob,IShape,zob2dv,Et);
      DStr.ChangeShapeInterferences(IShape).Append(InterFv);
      Et = TopAbs::Reverse(TopAbs::Compose(OVtx,OArcprolop));
      Standard_Integer Iop = DStr.AddShape(Fop);
      Handle(TopOpeBRepDS_SurfaceCurveInterference)
	Interfop = ChFi3d_FilCurveInDS(IZob,Iop,zob2dop,Et);
      DStr.ChangeShapeInterferences(Iop).Append(Interfop);
      Handle(TopOpeBRepDS_CurvePointInterference) interfprol;
      if (variant1)
	interfprol = ChFi3d_FilVertexInDS(TopAbs_FORWARD,IZob,IVtx,Udeb);
      else {
	Standard_Integer IV2 = DStr.AddShape(V2); // VARIANT 2
	interfprol = ChFi3d_FilVertexInDS(TopAbs_FORWARD,IZob,IV2,Udeb);
      }
      DStr.ChangeCurveInterferences(IZob).Append(interfprol);
      Standard_Integer icc = stripe->IndexPoint(isfirst,IFopArc);
      interfprol = ChFi3d_FilPointInDS(TopAbs_REVERSED,IZob,icc,Ufin);
      DStr.ChangeCurveInterferences(IZob).Append(interfprol);
      if (variant1) {
	if (IFopArc == 1) box1.Add( zob3d->Value(Ufin) );
	else              box2.Add( zob3d->Value(Ufin) );
      }
      else {
        // cut off existing Arcprol
        Standard_Integer iArcprol = DStr.AddShape(Arcprol);
        interfprol = ChFi3d_FilPointInDS(OVtx,iArcprol,icc,Udeb);
        DStr.ChangeShapeInterferences(Arcprol).Append(interfprol);
      }
    }
  }
  ChFi3d_EnlargeBox(DStr,stripe,Fd,box1,box2,isfirst);
  if (CV1.IsOnArc()) {
    ChFi3d_EnlargeBox(CV1.Arc(),myEFMap(CV1.Arc()),CV1.ParameterOnArc(),box1);
  }
  if (CV2.IsOnArc()) {
    ChFi3d_EnlargeBox(CV2.Arc(),myEFMap(CV2.Arc()),CV2.ParameterOnArc(),box2);
  }
  if  (!CV1.IsVertex())
    ChFi3d_SetPointTolerance(DStr,box1,stripe->IndexPoint(isfirst,1));
  if (!CV2.IsVertex())
    ChFi3d_SetPointTolerance(DStr,box2,stripe->IndexPoint(isfirst,2));

#ifdef DEB
  ChFi3d_ResultChron(ch, t_sameinter);//result perf condition if (same &&inter)
#endif
}

//=======================================================================
//function : cherche_face
//purpose  : find face F belonging to the map, different from faces
//           F1  F2 F3 and containing edge E
//=======================================================================

static void cherche_face (const TopTools_ListOfShape & map,
                          const TopoDS_Edge & E,
                          const TopoDS_Face & F1,
                          const TopoDS_Face & F2,
                          const TopoDS_Face & F3,
                          TopoDS_Face &  F)
{ TopoDS_Face Fcur;
  Standard_Boolean trouve=Standard_False;
  TopTools_ListIteratorOfListOfShape It;
  Standard_Integer ie;
  for (It.Initialize(map);It.More()&&!trouve;It.Next())
  { Fcur=TopoDS::Face (It.Value());
    if (!Fcur.IsSame(F1) && !Fcur.IsSame(F2)&& !Fcur.IsSame(F3) )
    { TopTools_IndexedMapOfShape  MapE;
      TopExp::MapShapes( Fcur,TopAbs_EDGE,MapE);
      for ( ie=1; ie<= MapE.Extent()&&!trouve;  ie++)
      {
        TopoDS_Shape aLocalShape = TopoDS_Shape (MapE(ie));
        if (E.IsSame(TopoDS::Edge(aLocalShape)))
          //            if (E.IsSame(TopoDS::Edge(TopoDS_Shape (MapE(ie)))))
        { F= Fcur; trouve=Standard_True;}
      }
    }
  }
}

//=======================================================================
//function : cherche_edge1
//purpose  : find common edge between faces F1 and F2
//=======================================================================

static void cherche_edge1 (const TopoDS_Face & F1,
                    const TopoDS_Face & F2,
                          TopoDS_Edge & Edge)
{ Standard_Integer i,j;
  TopoDS_Edge Ecur1,Ecur2;
  Standard_Boolean trouve=Standard_False;
  TopTools_IndexedMapOfShape  MapE1,MapE2;
  TopExp::MapShapes( F1,TopAbs_EDGE,MapE1);
  TopExp::MapShapes( F2,TopAbs_EDGE,MapE2);
  for ( i=1; i<= MapE1.Extent()&&!trouve; i++)
      {
	TopoDS_Shape aLocalShape = TopoDS_Shape (MapE1(i));
	Ecur1=TopoDS::Edge(aLocalShape);
//	Ecur1=TopoDS::Edge(TopoDS_Shape (MapE1(i)));
        for ( j=1; j<= MapE2.Extent()&&!trouve; j++)
            {
	      aLocalShape = TopoDS_Shape (MapE2(j));
	      Ecur2=TopoDS::Edge(aLocalShape);
//	      Ecur2=TopoDS::Edge(TopoDS_Shape (MapE2(j)));
            if (Ecur2.IsSame(Ecur1))
               {Edge=Ecur1;trouve=Standard_True;}
            }
      }
}

//=======================================================================
//function : containV
//purpose  : return true if vertex V belongs to F1
//=======================================================================

static Standard_Boolean  containV(const TopoDS_Face & F1,
                           const TopoDS_Vertex & V)
{ Standard_Integer i;
  TopoDS_Vertex Vcur;
  Standard_Boolean trouve=Standard_False;
  Standard_Boolean contain=Standard_False;
  TopTools_IndexedMapOfShape  MapV;
  TopExp::MapShapes( F1,TopAbs_VERTEX,MapV);
  for ( i=1; i<= MapV.Extent()&&!trouve; i++)
      {
	TopoDS_Shape aLocalShape = TopoDS_Shape (MapV(i));
	Vcur=TopoDS::Vertex(aLocalShape);
//	Vcur=TopoDS::Vertex(TopoDS_Shape (MapV(i)));
        if (Vcur.IsSame(V) )
            {contain=Standard_True; trouve=Standard_True;}
      }
  return contain;
}

//=======================================================================
//function : containE
//purpose  : return true if edge E belongs to F1
//=======================================================================

static Standard_Boolean  containE(const TopoDS_Face & F1,
                           const TopoDS_Edge & E)
{ Standard_Integer i;
  TopoDS_Edge Ecur;
  Standard_Boolean trouve=Standard_False;
  Standard_Boolean contain=Standard_False;
  TopTools_IndexedMapOfShape  MapE;
  TopExp::MapShapes( F1,TopAbs_EDGE,MapE);
  for ( i=1; i<= MapE.Extent()&&!trouve; i++)
      {
	TopoDS_Shape aLocalShape = TopoDS_Shape (MapE(i));
	Ecur=TopoDS::Edge(aLocalShape);
//	Ecur=TopoDS::Edge(TopoDS_Shape (MapE(i)));
        if (Ecur.IsSame(E) )
            {contain=Standard_True; trouve=Standard_True;}
      }
  return contain;
}


//=======================================================================
//function : IsShrink
//purpose  : check if U (if <isU>==True) or V of points of <PC> is within
//           <tol> from <Param>, check points between <Pf> and <Pl>
//=======================================================================

static Standard_Boolean IsShrink(const Geom2dAdaptor_Curve PC,
                                 const Standard_Real       Pf,
                                 const Standard_Real       Pl,
                                 const Standard_Real       Param,
                                 const Standard_Boolean    isU,
                                 const Standard_Real       tol)
{
  switch (PC.GetType()) {
  case GeomAbs_Line: {
    gp_Pnt2d P1 = PC.Value(Pf);
    gp_Pnt2d P2 = PC.Value(Pl);
    if (Abs(P1.Coord(isU ? 1 : 2) - Param) <= tol &&
	Abs(P2.Coord(isU ? 1 : 2) - Param) <= tol )
      return Standard_True;
    else
      return Standard_False;
  }
  case GeomAbs_BezierCurve:
  case GeomAbs_BSplineCurve: {
    math_FunctionSample aSample (Pf,Pl,10);
    Standard_Integer i;
    for (i=1; i<=aSample.NbPoints(); i++) {
      gp_Pnt2d P = PC.Value(aSample.GetParameter(i));
      if (Abs(P.Coord(isU ? 1 : 2) - Param) > tol )
	return Standard_False;
    }
    return Standard_True;
  }
  default:;
  }
  return Standard_False;
}
//=======================================================================
//function : PerformIntersectionAtEnd
//purpose  :
//=======================================================================

void ChFi3d_Builder::PerformIntersectionAtEnd(const Standard_Integer Index)
{

  // intersection at end of fillet with at least two faces
  // process the following cases:
  // - top has n (n>3) adjacent edges
  // - top has 3 edges and fillet on one of edges touches
  //   more than one face

#ifdef DEB
  OSD_Chronometer ch;// init perf
#endif

  TopOpeBRepDS_DataStructure& DStr= myDS->ChangeDS();
  const Standard_Integer nn=15;
  ChFiDS_ListIteratorOfListOfStripe It;
  It.Initialize(myVDataMap(Index));
  Handle(ChFiDS_Stripe) stripe = It.Value();
  const Handle(ChFiDS_Spine) spine = stripe->Spine();
  ChFiDS_SequenceOfSurfData& SeqFil =
    stripe->ChangeSetOfSurfData()->ChangeSequence();
  const TopoDS_Vertex& Vtx = myVDataMap.FindKey(Index);
  Standard_Integer sens = 0,num,num1;
  Standard_Boolean couture=Standard_False,isfirst;
  //Standard_Integer sense;
  TopoDS_Edge edgelibre1,edgelibre2,EdgeSpine;
  Standard_Boolean bordlibre;
  // determine the number of faces and edges
  TopTools_Array1OfShape tabedg(0,nn);
  TopoDS_Face F1,F2;
  Standard_Integer nface=ChFi3d_nbface(myVFMap(Vtx));
  TopTools_ListIteratorOfListOfShape ItF;
  Standard_Integer nbarete;
  nbarete=ChFi3d_NbNotDegeneratedEdges(Vtx,myVEMap);
  ChFi3d_ChercheBordsLibres(myVEMap,Vtx,bordlibre,edgelibre1,edgelibre2);
  if (bordlibre) nbarete=(nbarete-2)/2 +2;
  else           nbarete=nbarete/2;
  // it is determined if there is an edge of sewing and it face

  TopoDS_Face facecouture;
  TopoDS_Edge edgecouture;

  Standard_Boolean trouve=Standard_False;
  for(ItF.Initialize(myVFMap(Vtx));ItF.More()&&!couture;ItF.Next()) {
    TopoDS_Face fcur = TopoDS::Face(ItF.Value());
    ChFi3d_CoutureOnVertex(fcur,Vtx,couture,edgecouture);
    if (couture)
      facecouture=fcur;
  }
  // it is determined if one of edges adjacent to the fillet is regular
  Standard_Boolean reg1,reg2;
  TopoDS_Edge Ecur,Eadj1,Eadj2;
  TopoDS_Face Fga,Fdr;
  TopoDS_Vertex Vbid1;
  Standard_Integer nbsurf,nbedge;
  reg1=Standard_False;
  reg2=Standard_False;
  nbsurf= SeqFil.Length();
  nbedge = spine->NbEdges();
  num = ChFi3d_IndexOfSurfData(Vtx,stripe,sens);
  isfirst = (sens == 1);
  ChFiDS_State state;
  if (isfirst) {
    EdgeSpine=spine->Edges(1);
    num1=num+1;
    state = spine->FirstStatus();
  }
  else {
    EdgeSpine=spine->Edges(nbedge);
    num1=num-1;
    state = spine->LastStatus();
  }
  if (nbsurf!=nbedge && nbsurf!=1) {
    ChFi3d_edge_common_faces(myEFMap(EdgeSpine),F1,F2);
    if (F1.IsSame(facecouture)) Eadj1=edgecouture;
    else ChFi3d_cherche_element(Vtx,EdgeSpine,F1,Eadj1,Vbid1);
    ChFi3d_edge_common_faces(myEFMap(Eadj1),Fga,Fdr);
//  Modified by Sergey KHROMOV - Fri Dec 21 17:57:32 2001 Begin
//  reg1=BRep_Tool::Continuity(Eadj1,Fga,Fdr)!=GeomAbs_C0;
    reg1=isTangentFaces(Eadj1,Fga,Fdr);
//  Modified by Sergey KHROMOV - Fri Dec 21 17:57:33 2001 End
    if (F2.IsSame(facecouture)) Eadj2=edgecouture;
    else ChFi3d_cherche_element(Vtx,EdgeSpine,F2,Eadj2,Vbid1);
    ChFi3d_edge_common_faces(myEFMap(Eadj2),Fga,Fdr);
//  Modified by Sergey KHROMOV - Fri Dec 21 17:58:22 2001 Begin
//  reg2=BRep_Tool::Continuity(Eadj2,Fga,Fdr)!=GeomAbs_C0;
    reg2=isTangentFaces(Eadj2,Fga,Fdr);
//  Modified by Sergey KHROMOV - Fri Dec 21 17:58:24 2001 End

// two faces common to the edge are found
    if (reg1 || reg2) {
      Standard_Boolean compoint1=Standard_False;
      Standard_Boolean compoint2=Standard_False;
      ChFiDS_CommonPoint cp1, cp2;
      cp1 = SeqFil(num1)->ChangeVertex (isfirst,1);
      cp2 = SeqFil(num1)->ChangeVertex (isfirst,2);
      if (cp1.IsOnArc()) {
	if (cp1.Arc().IsSame(Eadj1)||cp1.Arc().IsSame(Eadj2))
	  compoint1=Standard_True;
      }
      if (cp2.IsOnArc()) {
	if (cp2.Arc().IsSame(Eadj1)||cp2.Arc().IsSame(Eadj2))
	  compoint2=Standard_True;
      }
      if (compoint1 && compoint2) {
	SeqFil.Remove(num);
        reg1=Standard_False; reg2=Standard_False;
      }
    }
  }
// there is only one face at end if FindFace is true and if the face
// is not the face with sewing edge
  TopoDS_Face face;
  Handle(ChFiDS_SurfData) Fd = SeqFil.ChangeValue(num);
  ChFiDS_CommonPoint& CV1 = Fd->ChangeVertex(isfirst,1);
  ChFiDS_CommonPoint& CV2 = Fd->ChangeVertex(isfirst,2);
  Standard_Boolean onecorner=Standard_False;
  if (FindFace(Vtx,CV1,CV2,face)) {
      if (!couture) onecorner =Standard_True;
      else if (!face.IsSame(facecouture))
            onecorner=Standard_True;
    }
  if (onecorner) {
    if (ChFi3d_Builder::MoreSurfdata(Index)) {
      ChFi3d_Builder::PerformMoreSurfdata(Index);
      return;
    }
  }
  if (!onecorner && (reg1||reg2) && !couture && state!=ChFiDS_OnSame) {
    PerformMoreThreeCorner (Index,1);
    return;
  }
  Handle(GeomAdaptor_HSurface) HGs = ChFi3d_BoundSurf(DStr,Fd,1,2);
  ChFiDS_FaceInterference Fi1 = Fd->InterferenceOnS1();
  ChFiDS_FaceInterference Fi2 = Fd->InterferenceOnS2();
  GeomAdaptor_Surface& Gs = HGs->ChangeSurface();
  Handle(BRepAdaptor_HSurface) HBs  = new BRepAdaptor_HSurface();
  BRepAdaptor_Surface& Bs  = HBs->ChangeSurface();
  Handle(Geom_Curve) Cc;
  Handle(Geom2d_Curve) Pc,Ps;
  Standard_Real Ubid,Vbid;
  TopAbs_Orientation orsurfdata;
  orsurfdata=Fd->Orientation();
  Standard_Integer IsurfPrev=0, Isurf=Fd->Surf();
  Handle(ChFiDS_SurfData) SDprev;
  if (num1>0 && num1<=SeqFil.Length()) {
    SDprev = SeqFil(num1);
    IsurfPrev = SDprev->Surf();
  }
  // calculate the orientation of curves at end

  Standard_Real tolpt=1.e-4;
  Standard_Real tolreached;
  TopAbs_Orientation orcourbe,orface,orien;

  stripe->SetIndexPoint(ChFi3d_IndexPointInDS(CV1,DStr),isfirst,1);
  stripe->SetIndexPoint(ChFi3d_IndexPointInDS(CV2,DStr),isfirst,2);

//  gp_Pnt p3d;
//  gp_Pnt2d p2d;
  Standard_Real dist;
  Standard_Integer Ishape1=Fd->IndexOfS1();
#ifndef DEB
  TopAbs_Orientation trafil1 = TopAbs_FORWARD;
#else
  TopAbs_Orientation trafil1;
#endif
  if (Ishape1 != 0) {
    if (Ishape1 > 0) {
      trafil1 = DStr.Shape(Ishape1).Orientation();
    }
#ifdef DEB
    else {
      cout<<"erreur"<<endl;
    }
#endif
    trafil1 = TopAbs::Compose(trafil1,Fd->Orientation());

    trafil1 = TopAbs::Compose(TopAbs::Reverse(Fi1.Transition()),trafil1);
  }
#ifdef DEB
  else cout<<"erreur"<<endl;
#endif
  // eap, Apr 22 2002, occ 293
//   Fi1.PCurveOnFace()->D0(Fi1.LastParameter(),p2d);
//   const Handle(Geom_Surface) Stemp =
//     BRep_Tool::Surface(TopoDS::Face(DStr.Shape(Ishape1)));
//   Stemp ->D0(p2d.X(),p2d.Y(),p3d);
//   dist=p3d.Distance(CV1.Point());
//   if (dist<tolpt) orcourbe=trafil1;
//   else            orcourbe=TopAbs::Reverse(trafil1);
  if (!isfirst) orcourbe=trafil1;
  else          orcourbe=TopAbs::Reverse(trafil1);

  // eap, Apr 22 2002, occ 293
  // variables to show OnSame situation
  Standard_Boolean isOnSame1, isOnSame2;
  // In OnSame situation, the case of degenerated FaceInterference curve
  // is probable when a corner cuts the ChFi3d earlier built on OnSame edge.
  // In such a case, chamfer face can partially shrink to a line and we need
  // to cut off that shrinked part
  // If <isOnSame1>, FaceInterference with F2 can be degenerated
  Standard_Boolean checkShrink, isShrink, isUShrink;
  isShrink = isUShrink = isOnSame1 = isOnSame2 = Standard_False;
  Standard_Real checkShrParam=0., prevSDParam=0.;
  gp_Pnt2d midP2d;
  Standard_Integer midIpoint=0;

  // find Fi1,Fi2 lengths used to extend ChFi surface
  // and by the way define necessity to check shrink
  gp_Pnt2d P2d1=Fi1.PCurveOnSurf()->Value(Fi1.Parameter(isfirst));
  gp_Pnt2d P2d2=Fi1.PCurveOnSurf()->Value(Fi1.Parameter(!isfirst));
  gp_Pnt aP1,aP2;
  HGs->D0( P2d1.X(),P2d1.Y(),aP1);
  HGs->D0( P2d2.X(),P2d2.Y(),aP2);
  Standard_Real Fi1Length=aP1.Distance(aP2);
//  Standard_Real eps = Precision::Confusion();
  checkShrink = (Fi1Length <= Precision::Confusion());
  
  gp_Pnt2d P2d3=Fi2.PCurveOnSurf()->Value(Fi2.Parameter(isfirst));
  gp_Pnt2d P2d4=Fi2.PCurveOnSurf()->Value(Fi2.Parameter(!isfirst));
  HGs->D0( P2d3.X(),P2d3.Y(),aP1);
  HGs->D0( P2d4.X(),P2d4.Y(),aP2);
  Standard_Real Fi2Length=aP1.Distance(aP2);
  checkShrink = checkShrink || (Fi2Length <= Precision::Confusion());

  if (checkShrink) {
    if (Abs(P2d2.Y()-P2d4.Y()) <= Precision::PConfusion()) {
      isUShrink = Standard_False;
      checkShrParam = P2d2.Y();
    } else if (Abs(P2d2.X()-P2d4.X()) <= Precision::PConfusion()) {
      isUShrink = Standard_True;
      checkShrParam = P2d2.X();
    }
    else
      checkShrink = Standard_False;
  }

  /***********************************************************************/
  //  find faces intersecting with the fillet and edges limiting intersections
  //  nbface is the nb of faces intersected, Face[i] contais the faces
  // to intersect (i=0.. nbface-1). Edge[i] contains edges limiting
  // the intersections (i=0 ..nbface)
  /**********************************************************************/

  Standard_Integer nb = 1,nbface;
  TopoDS_Edge E1 ,E2, Edge[nn],E,Ei,edgesau;
  TopoDS_Face  facesau;
  Standard_Boolean oneintersection1=Standard_False;
  Standard_Boolean oneintersection2=Standard_False;
  TopoDS_Face Face[nn],F,F3;
  TopoDS_Vertex V1,V2,V,Vfin;
  Standard_Boolean  findonf1=Standard_False,findonf2=Standard_False;
  TopTools_ListIteratorOfListOfShape It3;
  F1=TopoDS::Face(DStr.Shape(Fd->IndexOfS1()));
  F2=TopoDS::Face(DStr.Shape(Fd->IndexOfS2()));
  F3=F1;
  if (couture || bordlibre) nface=nface+1;
  if (nface==3) nbface=2;
  else nbface=nface-2;
  if (!CV1.IsOnArc()||!CV2.IsOnArc()) {
    PerformMoreThreeCorner(Index,1);
    return;
  }

  Edge[0]=CV1.Arc();
  Edge[nbface]=CV2.Arc();
  tabedg.SetValue(0,Edge[0]);
  tabedg.SetValue(nbface,Edge[nbface]);
  // processing of a fillet arriving on a vertex
  // edge contained in CV.Arc is not inevitably good
  // the edge concerned by the intersection is found

  Standard_Real dist1,dist2;
  if (CV1.IsVertex()) {
    trouve=Standard_False;
    /*TopoDS_Vertex */V=CV1.Vertex();
    for (It3.Initialize(myVEMap(V));It3.More()&&!trouve;It3.Next()) {
      E=TopoDS::Edge (It3.Value());
      if (!E.IsSame(Edge[0])&&(containE(F1,E)))
	trouve=Standard_True;
    }
    TopoDS_Vertex Vt,V3,V4;
    V1=TopExp::FirstVertex(Edge[0]);
    V2=TopExp::LastVertex(Edge[0]);
    if (V.IsSame(V1)) Vt=V2;
    else Vt=V1;
    dist1=(BRep_Tool::Pnt(Vt)).Distance(BRep_Tool::Pnt(Vtx));
    V3=TopExp::FirstVertex(E);
    V4=TopExp::LastVertex(E);
    if (V.IsSame(V3)) Vt=V4;
    else Vt=V3;
    dist2=(BRep_Tool::Pnt(Vt)).Distance(BRep_Tool::Pnt(Vtx));
    if (dist2<dist1) {
      Edge[0]=E;
      TopAbs_Orientation ori;
      if (V2.IsSame(V3)||V1.IsSame(V4)) ori=CV1.TransitionOnArc();
      else ori=TopAbs::Reverse(CV1.TransitionOnArc());
      Standard_Real par= BRep_Tool::Parameter(V,Edge[0]);
      Standard_Real tol= CV1.Tolerance();
      CV1.SetArc(tol,Edge[0],par,ori);
    }
  }

  if (CV2.IsVertex()) {
    trouve=Standard_False;
    /*TopoDS_Vertex*/ V=CV2.Vertex();
    for (It3.Initialize(myVEMap(V));It3.More()&&!trouve;It3.Next()) {
      E=TopoDS::Edge (It3.Value());
      if (!E.IsSame(Edge[2])&&(containE(F2,E)))
	trouve=Standard_True;
    }
    TopoDS_Vertex Vt,V3,V4;
    V1=TopExp::FirstVertex(Edge[2]);
    V2=TopExp::LastVertex(Edge[2]);
    if (V.IsSame(V1)) Vt=V2;
    else Vt=V1;
    dist1=(BRep_Tool::Pnt(Vt)).Distance(BRep_Tool::Pnt(Vtx));
    V3=TopExp::FirstVertex(E);
    V4=TopExp::LastVertex(E);
    if (V.IsSame(V3)) Vt=V4;
    else Vt=V3;
    dist2=(BRep_Tool::Pnt(Vt)).Distance(BRep_Tool::Pnt(Vtx));
    if (dist2<dist1) {
      Edge[2]=E;
      TopAbs_Orientation ori;
      if (V2.IsSame(V3)||V1.IsSame(V4)) ori=CV2.TransitionOnArc();
      else ori=TopAbs::Reverse(CV2.TransitionOnArc());
      Standard_Real par= BRep_Tool::Parameter(V,Edge[2]);
      Standard_Real tol= CV2.Tolerance();
      CV2.SetArc(tol,Edge[2],par,ori);
    }
  }
  if (!onecorner) {
    // If there is a regular edge, the faces adjacent to it 
    // are not in Fd->IndexOfS1 or Fd->IndexOfS2

//     TopoDS_Face Find1 ,Find2;
//     if (isfirst)
//       edge=stripe->Spine()->Edges(1);
//     else  edge=stripe->Spine()->Edges(stripe->Spine()->NbEdges());
//     It3.Initialize(myEFMap(edge));
//     Find1=TopoDS::Face(It3.Value());
//     trouve=Standard_False;
//     for (It3.Initialize(myEFMap(edge));It3.More()&&!trouve;It3.Next()) {
//       F=TopoDS::Face (It3.Value());
//       if (!F.IsSame(Find1)) {
// 	Find2=F;trouve=Standard_True;
//       }
//     }

    // if nface =3 there is a top with 3 edges and a fillet 
    // and their common points are on different faces 
    // otherwise there is a case when a top has more than 3 edges

    if (nface==3) {
      if (CV1.IsVertex ()) findonf1=Standard_True;
      if (CV2.IsVertex ()) findonf2=Standard_True;
      if (!findonf1) {
	TopTools_IndexedMapOfShape  MapV;
	TopExp::MapShapes(Edge[0], TopAbs_VERTEX, MapV);
	if (MapV.Extent()==2)
	  if (!MapV(1).IsSame(Vtx) && !MapV(2).IsSame(Vtx))
	    findonf1=Standard_True;
      }
      if (!findonf2) {
	TopTools_IndexedMapOfShape  MapV;
        TopExp::MapShapes(Edge[2], TopAbs_VERTEX, MapV);
        if (MapV.Extent()==2)
          if (!MapV(1).IsSame(Vtx) && !MapV(2).IsSame(Vtx))
	    findonf2=Standard_True;
      }

      // detect and process OnSame situatuation
      if (state == ChFiDS_OnSame) {
	TopoDS_Edge threeE[3];
	ChFi3d_cherche_element(Vtx,EdgeSpine, F1,threeE[0], V2);
	ChFi3d_cherche_element(Vtx,EdgeSpine, F2,threeE[1], V2);
	threeE[2] = EdgeSpine;
	if (ChFi3d_EdgeState(threeE,myEFMap) == ChFiDS_OnSame) {
          isOnSame1 = Standard_True;
          nb = 1;
          Edge[0] = threeE[0];
          ChFi3d_cherche_face1(myEFMap(Edge[0]),F1,Face[0]);
          if (findonf2)
	    findonf1 = Standard_True; // not to look for Face[0] again
	  else
	    Edge[1]=CV2.Arc();
        }
	else {
          isOnSame2 = Standard_True;
	}
      }

      // findonf1 findonf2 show if F1 and/or F2 are adjacent
      // to many faces at end
      // the faces at end and intersected edges are found

      if (findonf1 && !isOnSame1) {
	if (CV1.TransitionOnArc()==TopAbs_FORWARD)
	  V1=TopExp::FirstVertex(CV1.Arc());
	else
	  V1=TopExp::LastVertex(CV1.Arc());
	ChFi3d_cherche_face1(myEFMap(CV1.Arc()),F1,Face[0]);
	nb=1;
	Ei=Edge[0];
	while (!V1.IsSame(Vtx)) {
	  ChFi3d_cherche_element(V1,Ei,F1,E,V2);
	  V1=V2; Ei=E;
	  ChFi3d_cherche_face1(myEFMap(E),F1,Face[nb]);
	  cherche_edge1(Face[nb-1],Face[nb],Edge[nb]);
	  nb++;
 	  if (nb>=nn) Standard_Failure::Raise
 	    ("IntersectionAtEnd : the max number of faces reached");
	}
	if (!findonf2)  Edge[nb]=CV2.Arc();
      }
      if (findonf2  && !isOnSame2) {
	if (!findonf1 )  nb=1;
	V1=Vtx;
	if (CV2.TransitionOnArc()==TopAbs_FORWARD)
	  Vfin=TopExp::LastVertex(CV2.Arc());
	else
	  Vfin=TopExp::FirstVertex(CV2.Arc());
	if (!findonf1) ChFi3d_cherche_face1(myEFMap(CV1.Arc()),F1,Face[nb-1]);
	ChFi3d_cherche_element(V1,EdgeSpine,F2,E,V2);
	Ei=E;V1=V2;
	while (!V1.IsSame(Vfin)) {
	  ChFi3d_cherche_element(V1,Ei,F2,E,V2);
	  Ei=E;
	  V1=V2;
	  ChFi3d_cherche_face1(myEFMap(E),F2,Face[nb]);
	  cherche_edge1(Face[nb-1],Face[nb],Edge[nb]);
	  nb++;
	  if (nb>=nn) Standard_Failure::Raise
	    ("IntersectionAtEnd : the max number of faces reached");
	}
	Edge[nb]=CV2.Arc();
      }
      if (isOnSame2) {
	cherche_edge1(Face[nb-1],F2,Edge[nb]);
	Face[nb] = F2;
      }

      nbface=nb;
    }

    else {

//  this is the case when a top has more than three edges
//  the faces and edges concerned are found
      Standard_Boolean /*trouve,*/possible1, possible2;
      trouve = possible1 = possible2 = Standard_False;
      TopExp_Explorer ex;
      nb=0;
      for (ex.Init(CV1.Arc(),TopAbs_VERTEX);ex.More();ex.Next()) {
	if (Vtx.IsSame(ex.Current())) possible1 = Standard_True;
      }
      for (ex.Init(CV2.Arc(),TopAbs_VERTEX);ex.More();ex.Next()) {
	if (Vtx.IsSame(ex.Current())) possible2 = Standard_True;
      }
      if ((possible1 && possible2) || (!possible1 && !possible2) || (nbarete > 4)) {
	while (!trouve) {
	  nb++;
	  if (nb!=1) F3=Face[nb-2];
	  Face[nb-1]=F3;
	  if (CV1.Arc().IsSame(edgelibre1))
	    cherche_face(myVFMap(Vtx),edgelibre2,F1,F2,F3,Face[nb-1]);
	  else if (CV1.Arc().IsSame(edgelibre2))
	    cherche_face(myVFMap(Vtx),edgelibre1,F1,F2,F3,Face[nb-1]);
	  else cherche_face(myVFMap(Vtx),Edge[nb-1],F1,F2,F3,Face[nb-1]);
	  ChFi3d_cherche_edge(Vtx,tabedg,Face[nb-1],Edge[nb],V);
	  tabedg.SetValue(nb,Edge[nb]);
	  if (Edge[nb].IsSame(CV2.Arc())) trouve=Standard_True;
	}
	nbface=nb;
      }
      else {
	IntersectMoreCorner (Index);
	return;
      }
      if (nbarete==4) {
	// if two consecutive edges are G1 there is only one face of intersection
	Standard_Real ang1=0.0;
        TopoDS_Vertex Vcom;
        trouve=Standard_False;
        ChFi3d_cherche_vertex ( Edge[0],Edge[1],Vcom,trouve);
        if (Vcom.IsSame(Vtx)) ang1=ChFi3d_AngleEdge(Vtx,Edge[0],Edge[1]);
	if (Abs(ang1-PI)<0.01) {
	  oneintersection1=Standard_True;
	  facesau=Face[0];
	  edgesau=Edge[1];
	  Face[0]=Face[1];
	  Edge[1]=Edge[2];
	  nbface=1;
	}

	if (!oneintersection1) {
          trouve=Standard_False;
          ChFi3d_cherche_vertex ( Edge[1],Edge[2],Vcom,trouve);
          if (Vcom.IsSame(Vtx)) ang1=ChFi3d_AngleEdge(Vtx,Edge[1],Edge[2]);
	  if (Abs(ang1-PI)<0.01) {
	    oneintersection2=Standard_True;
	    facesau=Face[1];
	    edgesau=Edge[1];
	    Edge[1]=Edge[2];
	    nbface=1;
	  }
	}
      }
      else if (nbarete==5) {
	//pro15368
//  Modified by Sergey KHROMOV - Fri Dec 21 18:07:43 2001 End
	Standard_Boolean isTangent0 = isTangentFaces(Edge[0],F1,Face[0]);
	Standard_Boolean isTangent1 = isTangentFaces(Edge[1],Face[0],Face[1]);
	Standard_Boolean isTangent2 = isTangentFaces(Edge[2],Face[1],Face[2]);
	if ((isTangent0 || isTangent2) && isTangent1) {
//         GeomAbs_Shape cont0,cont1,cont2;
//         cont0=BRep_Tool::Continuity(Edge[0],F1,Face[0]);
//         cont1=BRep_Tool::Continuity(Edge[1],Face[0],Face[1]);
//         cont2=BRep_Tool::Continuity(Edge[2],Face[1],Face[2]);
//         if ((cont0!=GeomAbs_C0 || cont2!=GeomAbs_C0) && cont1!=GeomAbs_C0) {
//  Modified by Sergey KHROMOV - Fri Dec 21 18:07:49 2001 Begin
          facesau=Face[0];
          edgesau=Edge[0];
          nbface=1;
          Edge[1]=Edge[3];
          Face[0]=Face[2];
          oneintersection1=Standard_True;
        }
      }
    }
  }
  else {
    nbface=1;
    Face[0]=face;
    Edge[1]=Edge[2];
  }

  TColStd_Array1OfReal Pardeb(1,4),Parfin(1,4);
  gp_Pnt2d pfil1,pfac1,pfil2,pfac2,pint,pfildeb;
  Handle(Geom2d_Curve) Hc1,Hc2;
  IntCurveSurface_HInter inters;
  Standard_Integer proledge[nn],prolface[nn+1];// last prolface[nn] is for Fd
  Standard_Integer shrink[nn];
  TopoDS_Face faceprol[nn];
  Standard_Integer indcurve[nn],indpoint2=0,indpoint1 = 0;
  Handle (TopOpeBRepDS_CurvePointInterference) Interfp1, Interfp2, Interfedge[nn];
  Handle (TopOpeBRepDS_SurfaceCurveInterference) Interfc,InterfPC[nn],InterfPS[nn];
  Standard_Real u2,v2,p1,p2,paredge1;
  Standard_Real  paredge2 = 0.,tolex = 1.e-4;
  Standard_Boolean extend=Standard_False;
  Handle(Geom_Surface) Sfacemoins1,Sface;
  /***************************************************************************/
  // calculate intersection of the fillet and each face
  // and storage in the DS
  /***************************************************************************/
  for (nb=1;nb<=nbface;nb++) {
    prolface[nb-1]=0;
    proledge[nb-1]=0;
    shrink  [nb-1]=0;
  }
  proledge[nbface]=0;
  prolface[nn]=0;
  if (oneintersection1||oneintersection2) faceprol[1]=facesau;
  if (!isOnSame1 && !isOnSame2)
    checkShrink = Standard_False;
  // in OnSame situation we need intersect Fd with Edge[0] or Edge[nbface] as well
  if (isOnSame1) nb=0;
  else           nb=1;
  Standard_Boolean intersOnSameFailed = Standard_False;
  
  for ( ; nb<=nbface; nb++) {
    extend=Standard_False;
    E2=Edge[nb];
    if (!nb)
      F=F1;
    else {
      F=Face[nb-1];
      if (!prolface[nb-1]) faceprol[nb-1]=F;
    }
    Sfacemoins1=BRep_Tool::Surface(F);
    Handle(Geom_Curve) cint;
    Handle(Geom2d_Curve) C2dint1, C2dint2,cface,cfacemoins1;

    ///////////////////////////////////////////////////////
    // determine intersections of edges and the fillet
    // to find limitations of intersections face - fillet
    ///////////////////////////////////////////////////////

    if (nb==1) {
      Hc1 = BRep_Tool::CurveOnSurface(Edge[0],Face[0],Ubid,Ubid);
      if (isOnSame1) {
        // update interference param on Fi1 and point of CV1
        if (prolface[0]) Bs.Initialize(faceprol[0], Standard_False);
        else             Bs.Initialize(Face[0], Standard_False);
        const Handle(Geom_Curve)& c3df = DStr.Curve(Fi1.LineIndex()).Curve();
        Standard_Real Ufi= Fi2.Parameter(isfirst);
        ChFiDS_FaceInterference& Fi = Fd->ChangeInterferenceOnS1();
        if (!IntersUpdateOnSame (HGs,HBs,c3df,F1,Face[0],Edge[0],Vtx,isfirst,10*tolesp, // in
				 Fi,CV1,pfac1,Ufi))   // out
	  Standard_Failure::Raise("IntersectionAtEnd: pb intersection Face - Fi");
        Fi1 = Fi;
        if (intersOnSameFailed) { // probable at fillet building
	  // look for paredge2
	  Geom2dAPI_ProjectPointOnCurve proj;
	  if (C2dint2.IsNull()) proj.Init(pfac1,Hc1);
	  else                  proj.Init(pfac1,C2dint2);
	  paredge2 = proj.LowerDistanceParameter();
        }
        // update stripe point
        TopOpeBRepDS_Point tpoint (CV1.Point(),tolesp);
        indpoint1=DStr.AddPoint(tpoint);
        stripe->SetIndexPoint(indpoint1,isfirst,1);
        // reset arc of CV1
        TopoDS_Vertex vert1,vert2;
        TopExp::Vertices(Edge[0],vert1,vert2);
        TopAbs_Orientation arcOri = Vtx.IsSame(vert1) ? TopAbs_FORWARD : TopAbs_REVERSED;
        CV1.SetArc(tolesp,Edge[0],paredge2,arcOri);
      }
      else {
        if (Hc1.IsNull()) {
          // curve 2d not found. Sfacemoins1 is extended and projection is done there
          // CV1.Point ()
          ChFi3d_ExtendSurface(Sfacemoins1,prolface[0]);
          if (prolface[0]) {
            extend=Standard_True;
            BRep_Builder BRE;
            Standard_Real tol=BRep_Tool::Tolerance(F);
            BRE.MakeFace(faceprol[0],Sfacemoins1,F.Location(),tol);
            if (!isOnSame1) {
              GeomAdaptor_Surface Asurf;
              Asurf.Load(Sfacemoins1);
              Extrema_ExtPS ext (CV1.Point(),Asurf, tol,tol);
              Standard_Real  uc1,vc1;
              if (ext.IsDone()) {
                ext.Point(1).Parameter(uc1,vc1);
                pfac1.SetX(uc1);
                pfac1.SetY(vc1);
              }
            }
          }
        }
        else
          pfac1 = Hc1->Value(CV1.ParameterOnArc());
      }
      paredge1=CV1.ParameterOnArc();
      if (Fi1.LineIndex() != 0) {
        pfil1 = Fi1.PCurveOnSurf()->Value(Fi1.Parameter(isfirst));}
      else {
        pfil1 = Fi1.PCurveOnSurf()->Value(Fi1.Parameter(!isfirst));}
      pfildeb=pfil1;
    }
    else {
      pfil1=pfil2;
      paredge1=paredge2;
      pfac1=pint;
    }

    if (nb!=nbface || isOnSame2) {
      Standard_Integer nbp;

      Handle(Geom_Curve) C;
      C=BRep_Tool::Curve(E2,Ubid,Vbid);
      Handle(Geom_TrimmedCurve) Ctrim = new Geom_TrimmedCurve(C,Ubid,Vbid);
      Standard_Real Utrim,Vtrim;
      Utrim=Ctrim->BasisCurve()->FirstParameter();
      Vtrim=Ctrim->BasisCurve()->LastParameter();
      if (Ctrim->IsPeriodic()) {
        if (Ubid>Ctrim->Period()) {
          Ubid=(Utrim+Vtrim)/2;
          Vbid= Vtrim;
        }
        else {
          Ubid=Utrim;
          Vbid=(Utrim+Vtrim)/2;
        }
      }
      else {
        Ubid=Utrim;
        Vbid=Vtrim;
      }
      Handle(GeomAdaptor_HCurve) HC =
        new GeomAdaptor_HCurve(C,Ubid,Vbid);
      GeomAdaptor_Curve & Cad =HC->ChangeCurve();
      inters.Perform(HC, HGs);
      if ( !prolface[nn] && ( !inters.IsDone() || (inters.NbPoints()==0) )) {
	// extend surface of conge
        Handle(Geom_BSplineSurface) S1=
          Handle(Geom_BSplineSurface)::DownCast(DStr.Surface(Fd->Surf()).Surface());
        if (!S1.IsNull()) {
          Standard_Real length = 0.5 * Max(Fi1Length,Fi2Length);
          GeomLib::ExtendSurfByLength(S1,length,1,Standard_False,!isfirst);
	  prolface[nn] = 1;
          if (!stripe->IsInDS(!isfirst)) {
            Gs.Load(S1);
            inters.Perform(HC, HGs);
            if (inters.IsDone()&& inters.NbPoints()!=0) {
              Fd->ChangeSurf(DStr.AddSurface(TopOpeBRepDS_Surface(S1, DStr.ChangeSurface(Isurf).Tolerance())));
              Isurf=Fd->Surf();
            }
          }
        }
      }
      if (!inters.IsDone() || (inters.NbPoints()==0)) {
        Handle(Geom_BSplineCurve) cd=Handle(Geom_BSplineCurve)::DownCast(C);
        Handle(Geom_BezierCurve) cd1=Handle(Geom_BezierCurve)::DownCast(C);
        if (!cd.IsNull() || !cd1.IsNull() ) {
          BRep_Builder BRE;
          Sface=BRep_Tool::Surface(Face[nb]);
          ChFi3d_ExtendSurface(Sface,prolface[nb]);
          Standard_Real tol=BRep_Tool::Tolerance(F);
          BRE.MakeFace(faceprol[nb],Sface,Face[nb].Location(),tol);
          if (nb && !prolface[nb-1]) {
	    ChFi3d_ExtendSurface(Sfacemoins1,prolface[nb-1]);
	    if (prolface[nb-1]) {
	      tol=BRep_Tool::Tolerance(F);
	      BRE.MakeFace(faceprol[nb-1],Sfacemoins1,F.Location(),tol);
	    }
	  }
	  else {
	    Standard_Integer prol = 0;
	    ChFi3d_ExtendSurface(Sfacemoins1,prol);
	  }
          GeomInt_IntSS InterSS(Sfacemoins1,Sface,1.e-7,1,1,1);
          if (InterSS.IsDone()) {
            trouve=Standard_False;
            for (Standard_Integer i=1; i<=InterSS.NbLines() && !trouve; i++) {
              extend=Standard_True;
              cint= InterSS.Line(i);
              C2dint1= InterSS.LineOnS1(i);
              C2dint2= InterSS.LineOnS2(i);
              Cad.Load(cint);
              inters.Perform(HC, HGs);
              trouve=inters.IsDone()&&inters.NbPoints()!=0;
	      // eap occ293, eval tolex on finally trimmed curves
//               Handle(GeomAdaptor_HSurface) H1=new GeomAdaptor_HSurface(Sfacemoins1);
//               Handle(GeomAdaptor_HSurface) H2=new GeomAdaptor_HSurface(Sface);
//              tolex=ChFi3d_EvalTolReached(H1,C2dint1,H2,C2dint2,cint);
	      tolex = InterSS.TolReached3d();
            }
          }
        }
      }
      if (inters.IsDone()) {
        nbp = inters.NbPoints();
        if (nbp==0) {
	  if (nb==0 || nb==nbface) 
	    intersOnSameFailed = Standard_True;
	  else {
	    PerformMoreThreeCorner (Index,1);
	    return;
	  }
        }
        else {
          gp_Pnt P=BRep_Tool::Pnt(Vtx);
          Standard_Real distmin=P.Distance(inters.Point(1).Pnt());
          nbp=1;
          for (Standard_Integer i=2;i<=inters.NbPoints();i++) {
            dist=P.Distance(inters.Point(i).Pnt());
            if (dist<distmin) {
              distmin=dist;
              nbp=i;
            }
          }
	  gp_Pnt2d pt2d (inters.Point(nbp).U(),inters.Point(nbp).V());
	  pfil2=pt2d;
	  paredge2=inters.Point(nbp).W();
	  if (!extend) {
	    cfacemoins1=BRep_Tool::CurveOnSurface(E2,F,u2,v2);
	    cface=BRep_Tool::CurveOnSurface(E2,Face[nb],u2,v2);
	    cfacemoins1->D0(paredge2,pfac2);
	    cface->D0(paredge2,pint);
	  }
	  else {
	    C2dint1->D0(paredge2,pfac2);
	    C2dint2->D0(paredge2,pint);
	  }
	}
      }
      else Standard_Failure::Raise("IntersectionAtEnd: pb intersection Face cb");
    }
    else {
      Hc2 = BRep_Tool::CurveOnSurface(E2,Face[nbface-1],Ubid,Ubid);
      if (Hc2.IsNull()) {
        // curve 2d is not found,  Sfacemoins1 is extended CV2.Point() is projected there

        ChFi3d_ExtendSurface(Sfacemoins1,prolface[0]);
        if (prolface[0]) {
          BRep_Builder BRE;
          extend=Standard_True;
          Standard_Real tol=BRep_Tool::Tolerance(F);
          BRE.MakeFace(faceprol[nb-1],Sfacemoins1,F.Location(),tol);
          GeomAdaptor_Surface Asurf;
          Asurf.Load(Sfacemoins1);
          Extrema_ExtPS ext (CV2.Point(),Asurf,tol,tol);
          Standard_Real  uc2,vc2;
          if (ext.IsDone()) {
            ext.Point(1).Parameter(uc2,vc2);
            pfac2.SetX(uc2);
            pfac2.SetY(vc2);
          }
        }
      }
      else pfac2 = Hc2->Value(CV2.ParameterOnArc());
      paredge2=CV2.ParameterOnArc();
      if (Fi2.LineIndex() != 0) {
        pfil2 = Fi2.PCurveOnSurf()->Value(Fi2.Parameter(isfirst));
      }
      else {
        pfil2 = Fi2.PCurveOnSurf()->Value(Fi2.Parameter(!isfirst));
      }
    }
    if (!nb) continue; // found paredge1 on Edge[0] in OnSame situation on F1

    if (nb==nbface && isOnSame2) {
      // update interference param on Fi2 and point of CV2
      if (prolface[nb-1]) Bs.Initialize(faceprol[nb-1]);
      else                Bs.Initialize(Face[nb-1]);
      const Handle(Geom_Curve)& c3df = DStr.Curve(Fi2.LineIndex()).Curve();
      Standard_Real Ufi= Fi1.Parameter(isfirst);
      ChFiDS_FaceInterference& Fi = Fd->ChangeInterferenceOnS2();
      if (!IntersUpdateOnSame (HGs,HBs,c3df,F2,F,Edge[nb],Vtx,isfirst,10*tolesp, // in
			       Fi,CV2,pfac2,Ufi))   // out
	Standard_Failure::Raise("IntersectionAtEnd: pb intersection Face - Fi");
      Fi2 = Fi;
      if (intersOnSameFailed) { // probable at fillet building
        // look for paredge2
	Geom2dAPI_ProjectPointOnCurve proj;
	if (extend)
	  proj.Init(pfac2, C2dint2);
	else 
	  proj.Init(pfac2, BRep_Tool::CurveOnSurface (E2,Face[nbface-1],Ubid,Ubid));
        paredge2 = proj.LowerDistanceParameter();
      }
      // update stripe point
      TopOpeBRepDS_Point tpoint (CV2.Point(),tolesp);
      indpoint2=DStr.AddPoint(tpoint);
      stripe->SetIndexPoint(indpoint2,isfirst,2);
      // reset arc of CV2
      TopoDS_Vertex vert1,vert2;
      TopExp::Vertices(Edge[nbface],vert1,vert2);
      TopAbs_Orientation arcOri = Vtx.IsSame(vert1) ? TopAbs_FORWARD : TopAbs_REVERSED;
      CV2.SetArc(tolesp,Edge[nbface],paredge2,arcOri);
    }


    if (prolface[nb-1]) Bs.Initialize(faceprol[nb-1]);
    else                Bs.Initialize(Face[nb-1]);

    // offset of parameters if they are not in the same period

    // commented by eap 30 May 2002 occ354
    // the following code may cause trimming a wrong part of periodic surface
    
//     Standard_Real  deb,xx1,xx2;
//     Standard_Boolean  moins2pi,moins2pi1,moins2pi2;
//     if (DStr.Surface(Fd->Surf()).Surface()->IsUPeriodic()) {
//       deb=pfildeb.X();
//       xx1=pfil1.X();
//       xx2=pfil2.X();
//       moins2pi=Abs(deb)< Abs(Abs(deb)-2*PI);
//       moins2pi1=Abs(xx1)< Abs(Abs(xx1)-2*PI);
//       moins2pi2=Abs(xx2)< Abs(Abs(xx2)-2*PI);
//       if (moins2pi1!=moins2pi2) {
//         if  (moins2pi) {
//           if (!moins2pi1) xx1=xx1-2*PI;
//           if (!moins2pi2) xx2=xx2-2*PI;
//         }
//         else {
//           if (moins2pi1) xx1=xx1+2*PI;
//           if (moins2pi2) xx2=xx2+2*PI;
//         }
//       }
//       pfil1.SetX(xx1);
//       pfil2.SetX(xx2);
//     }
//     if (couture || Sfacemoins1->IsUPeriodic()) {

//       Standard_Real ufmin,ufmax,vfmin,vfmax;
//       BRepTools::UVBounds(Face[nb-1],ufmin,ufmax,vfmin,vfmax);
//       deb=ufmin;
//       xx1=pfac1.X();
//       xx2=pfac2.X();
//       moins2pi=Abs(deb)< Abs(Abs(deb)-2*PI);
//       moins2pi1=Abs(xx1)< Abs(Abs(xx1)-2*PI);
//       moins2pi2=Abs(xx2)< Abs(Abs(xx2)-2*PI);
//       if (moins2pi1!=moins2pi2) {
//         if  (moins2pi) {
//           if (!moins2pi1) xx1=xx1-2*PI;
//           if (!moins2pi2) xx2=xx2-2*PI;
//         }
//         else {
//           if (moins2pi1) xx1=xx1+2*PI;
//           if (moins2pi2) xx2=xx2+2*PI;
//         }
//       }
//       pfac1.SetX(xx1);
//       pfac2.SetX(xx2);
//     }

    Pardeb(1)= pfil1.X();Pardeb(2) = pfil1.Y();
    Pardeb(3)= pfac1.X();Pardeb(4) = pfac1.Y();
    Parfin(1)= pfil2.X();Parfin(2) = pfil2.Y();
    Parfin(3)= pfac2.X();Parfin(4) = pfac2.Y();

    Standard_Real uu1,uu2,vv1,vv2;
    ChFi3d_Boite(pfac1,pfac2,uu1,uu2,vv1,vv2);
    ChFi3d_BoundFac(Bs,uu1,uu2,vv1,vv2);


    //////////////////////////////////////////////////////////////////////
    // calculate intersections face - fillet
    //////////////////////////////////////////////////////////////////////

    if (!ChFi3d_ComputeCurves(HGs,HBs,Pardeb,Parfin,Cc,
                              Ps,Pc,tolesp,tol2d,tolreached,nbface==1)) {
      PerformMoreThreeCorner (Index,1);
      return;
    }
    // storage of information in the data structure

    // evaluate tolerances
    p1=Cc->FirstParameter();
    p2=Cc->LastParameter();
    Standard_Real to1,to2;
    gp_Pnt2d  p2d1,p2d2;
    gp_Pnt P1,P2,P3,P4,P5,P6,P7,P8;
    HGs->D0(Pardeb(1),Pardeb(2),P1);
    HGs->D0(Parfin(1),Parfin(2),P2);
    HBs->D0(Pardeb(3),Pardeb(4),P3);
    HBs->D0(Parfin(3),Parfin(4),P4);
    Pc->D0(p1,p2d1);
    Pc->D0(p2,p2d2);
    HBs->D0(p2d1.X(),p2d1.Y(),P7);
    HBs->D0(p2d2.X(),p2d2.Y(),P8);
    Ps->D0(p1,p2d1);
    Ps->D0(p2,p2d2);
    HGs->D0(p2d1.X(),p2d1.Y(),P5);
    HGs->D0(p2d2.X(),p2d2.Y(),P6);
    to1 = Max (P1.Distance(P5)+P3.Distance(P7), tolreached);
    to2 = Max (P2.Distance(P6)+P4.Distance(P8), tolreached);


    //////////////////////////////////////////////////////////////////////
    // storage in the DS of the intersection curve
    //////////////////////////////////////////////////////////////////////

    Standard_Boolean Isvtx1=0;
    Standard_Boolean Isvtx2=0;
    Standard_Integer indice;

    if (nb==1)
    {
      indpoint1 = stripe->IndexPoint(isfirst,1);
      if (!CV1.IsVertex()) {
        TopOpeBRepDS_Point& tpt= DStr.ChangePoint(indpoint1);
        tpt.Tolerance ( Max (tpt.Tolerance(), to1));
      }
      else  Isvtx1=1;
    }
    if (nb==nbface)
    {
      indpoint2 = stripe->IndexPoint(isfirst,2);
      if (!CV2.IsVertex()) {
        TopOpeBRepDS_Point& tpt= DStr.ChangePoint(indpoint2);
        tpt.Tolerance ( Max (tpt.Tolerance(), to2));
      }
      else Isvtx2=1;
    }
    else
    {
      gp_Pnt point =Cc->Value(Cc->LastParameter());
      TopOpeBRepDS_Point tpoint (point,to2);
      indpoint2=DStr.AddPoint(tpoint);
    }
    
    if (nb!=1)
    {
      TopOpeBRepDS_Point& tpt= DStr.ChangePoint(indpoint1);
      tpt.Tolerance ( Max (tpt.Tolerance(), to1));
    }
    TopOpeBRepDS_Curve tcurv3d( Cc,tolreached);
    indcurve[nb-1]= DStr.AddCurve(tcurv3d);
    Interfp1=ChFi3d_FilPointInDS(TopAbs_FORWARD,indcurve[nb-1],
                                 indpoint1,Cc->FirstParameter(),Isvtx1);
    Interfp2=ChFi3d_FilPointInDS(TopAbs_REVERSED,indcurve[nb-1],
                                 indpoint2,Cc->LastParameter(),Isvtx2);

    DStr.ChangeCurveInterferences(indcurve[nb-1]).Append(Interfp1);
    DStr.ChangeCurveInterferences(indcurve[nb-1]).Append(Interfp2);

    //////////////////////////////////////////////////////////////////////
    // storage for the face
    //////////////////////////////////////////////////////////////////////

#ifndef DEB
    TopAbs_Orientation ori = TopAbs_FORWARD;
#else
    TopAbs_Orientation ori;
#endif
    orface=Face[nb-1].Orientation();
    if (orface==orsurfdata ) orien = TopAbs::Reverse(orcourbe);
    else                     orien = orcourbe ;
    // limitation of edges of faces
    if (nb==1) {
      Standard_Integer Iarc1= DStr.AddShape(Edge[0]);
      Interfedge[0]= ChFi3d_FilPointInDS(CV1.TransitionOnArc(),Iarc1,
                                         indpoint1,paredge1,Isvtx1);
      //DStr.ChangeShapeInterferences(Edge[0]).Append(Interfp1);
    }
    if (nb==nbface) {
      Standard_Integer Iarc2= DStr.AddShape(Edge[nb]);
      Interfedge[nb]= ChFi3d_FilPointInDS(CV2.TransitionOnArc() ,Iarc2,
                                          indpoint2,paredge2,Isvtx2);
      //DStr.ChangeShapeInterferences(Edge[nb]).Append(Interfp2);
    }

    if (nb!=nbface || oneintersection1 || oneintersection2) {
      if (nface==3) {
        V1= TopExp::FirstVertex(Edge[nb]);
        V2= TopExp::LastVertex(Edge[nb]);
        if (containV(F1,V1) || containV(F2,V1))
          ori=TopAbs_FORWARD;
        else if (containV(F1,V2) || containV(F2,V2))
          ori=TopAbs_REVERSED;
        else
	  Standard_Failure::Raise("IntersectionAtEnd : pb orientation");

        if (containV(F1,V1) && containV(F1,V2)) {
          dist1=(BRep_Tool::Pnt(V1)).Distance(BRep_Tool::Pnt(Vtx));
          dist2=(BRep_Tool::Pnt(V2)).Distance(BRep_Tool::Pnt(Vtx));
          if (dist1<dist2)  ori=TopAbs_FORWARD;
          else              ori=TopAbs_REVERSED;
        }
        if (containV(F2,V1) && containV(F2,V2)) {
          dist1=(BRep_Tool::Pnt(V1)).Distance(BRep_Tool::Pnt(Vtx));
          dist2=(BRep_Tool::Pnt(V2)).Distance(BRep_Tool::Pnt(Vtx));
          if (dist1<dist2)  ori=TopAbs_FORWARD;
          else              ori=TopAbs_REVERSED;
        }
      }
      else {
        if (TopExp::FirstVertex(Edge[nb]).IsSame(Vtx))
          ori= TopAbs_FORWARD;
        else ori=TopAbs_REVERSED;
      }
      if (!extend && !(oneintersection1 || oneintersection2)) {
        Standard_Integer Iarc2= DStr.AddShape(Edge[nb]);
        Interfedge[nb]= ChFi3d_FilPointInDS(ori,Iarc2,
                                            indpoint2,paredge2);
        //  DStr.ChangeShapeInterferences(Edge[nb]).Append(Interfp2);
      }
      else {
        if (!(oneintersection1 || oneintersection2) ) proledge[nb]=Standard_True;
        Standard_Integer indp1,indp2,ind;
        gp_Pnt pext;
        Standard_Real ubid,vbid;
        pext=BRep_Tool::Pnt(Vtx);
        GeomAdaptor_Curve cad;
        Handle(Geom_Curve) csau;
        if ( ! (oneintersection1 || oneintersection2)) {
          cad.Load(cint);
          csau=cint;
        }
        else {
          csau=BRep_Tool::Curve(edgesau,ubid,vbid );
          Handle(Geom_BoundedCurve) C1=
            Handle(Geom_BoundedCurve)::DownCast(csau);
          if (oneintersection1&&extend) {
            if (!C1.IsNull()) {
              gp_Pnt Pl;
              Pl=C1->Value(C1->LastParameter());
              //Standard_Boolean sens;
              sens=Pl.Distance(pext)<tolpt;
              GeomLib::ExtendCurveToPoint(C1,CV1.Point(),1,sens);
              csau=C1;
            }
          }
          else if (oneintersection2&&extend) {
            if (!C1.IsNull()) {
              gp_Pnt Pl;
              Pl=C1->Value(C1->LastParameter());
              //Standard_Boolean sens;
              sens=Pl.Distance(pext)<tolpt;
              GeomLib::ExtendCurveToPoint(C1,CV2.Point(),1,sens);
              csau=C1;
            }
          }
          cad.Load(csau);
        }
        Extrema_ExtPC ext(pext,cad,tolpt);
        Standard_Real par1, par2, par, ParVtx;
        Standard_Boolean vtx1=Standard_False;
        Standard_Boolean vtx2=Standard_False;
        par1=ext.Point(1).Parameter();
        ParVtx = par1;
        if (oneintersection1 || oneintersection2 ) {
          if (oneintersection2) {
            pext=CV2.Point();
            ind=indpoint2;
          }
          else {
            pext=CV1.Point();
            ind=indpoint1;
          }
          Extrema_ExtPC ext2(pext,cad,tolpt);
          par2=ext2.Point(1).Parameter();
        }
        else {
          par2=paredge2;
          ind=indpoint2;
        }
        if (par1>par2) {
          indp1=ind;
          indp2=DStr.AddShape(Vtx);
          vtx2=Standard_True;
          par=par1;
          par1=par2;
          par2=par;
        }
        else {
          indp1=DStr.AddShape(Vtx);
          indp2=ind;
          vtx1=Standard_True;
        }
        Handle(Geom_Curve) Ct=new Geom_TrimmedCurve (csau,par1,par2);
        TopAbs_Orientation orient;
        Cc->D0(Cc->FirstParameter(),P1);
        Cc->D0(Cc->LastParameter(),P2);
        Ct->D0(Ct->FirstParameter(),P3);
        Ct->D0(Ct->LastParameter(),P4);
        if (P2.Distance(P3)<tolpt || P1.Distance(P4)<tolpt) orient=orien;
        else orient=TopAbs::Reverse(orien);
        if (oneintersection1||oneintersection2) {
          indice=DStr.AddShape(Face[0]);
          if (extend) {
            DStr.SetNewSurface(Face[0],Sfacemoins1);
            ComputeCurve2d(Ct,faceprol[0],C2dint1);
          }
          else
          {
            TopoDS_Edge aLocalEdge = edgesau;
            if (edgesau.Orientation() != orient)
              aLocalEdge.Reverse();
            C2dint1 = BRep_Tool::CurveOnSurface(aLocalEdge,Face[0],ubid,vbid);
          }
        }
        else {
          indice=DStr.AddShape(Face[nb-1]);
          DStr.SetNewSurface(Face[nb-1],Sfacemoins1);
        }
	//// for periodic 3d curves ////
	if (cad.IsPeriodic())
	{
	  gp_Pnt2d P2d = BRep_Tool::Parameters( Vtx, Face[0] );
	  Geom2dAPI_ProjectPointOnCurve Projector( P2d, C2dint1 );
	  par = Projector.LowerDistanceParameter();
	  Standard_Real shift = par-ParVtx;
	  if (Abs(shift) > Precision::Confusion())
	  {
	    par1 += shift;
            par2 += shift;
          }
        }
        ////////////////////////////////

        Ct=new Geom_TrimmedCurve (csau,par1,par2);
        if (oneintersection1||oneintersection2) tolex=10*BRep_Tool::Tolerance(edgesau);
        if (extend) {
	  Handle(GeomAdaptor_HSurface) H1, H2;
          H1=new GeomAdaptor_HSurface(Sfacemoins1);
	  if (Sface.IsNull()) 
	    tolex = Max (tolex, ChFi3d_EvalTolReached(H1,C2dint1,H1,C2dint1,Ct));
	  else {
	    H2=new GeomAdaptor_HSurface(Sface);
	    tolex = Max (tolex, ChFi3d_EvalTolReached(H1,C2dint1,H2,C2dint2,Ct));
	  }
        }
        TopOpeBRepDS_Curve tcurv( Ct,tolex);
        Standard_Integer indcurv;
        indcurv=DStr.AddCurve(tcurv);
        Interfp1=ChFi3d_FilPointInDS(TopAbs_FORWARD,indcurv,indp1,par1,vtx1);
        Interfp2=ChFi3d_FilPointInDS(TopAbs_REVERSED,indcurv,indp2,par2,vtx2);
        DStr.ChangeCurveInterferences(indcurv).Append(Interfp1);
        DStr.ChangeCurveInterferences(indcurv).Append(Interfp2);

        Interfc=ChFi3d_FilCurveInDS(indcurv,indice ,C2dint1,orient);
        DStr.ChangeShapeInterferences(indice).Append(Interfc);
        if (oneintersection1||oneintersection2) {
          indice=DStr.AddShape(facesau);
          if (facesau.Orientation()==Face[0].Orientation())
            orient=TopAbs::Reverse(orient);
          if (extend) {
            ComputeCurve2d(Ct,faceprol[1],C2dint2);

          }
          else
          {
            TopoDS_Edge aLocalEdge = edgesau;
            if (edgesau.Orientation() != orient)
              aLocalEdge.Reverse();
            C2dint2 = BRep_Tool::CurveOnSurface(aLocalEdge,facesau,ubid,vbid);
            //Reverse for case of edgesau on closed surface (Face[0] is equal to facesau)
          }
        }
        else {
          indice=DStr.AddShape(Face[nb]);
          DStr.SetNewSurface(Face[nb],Sface);
          if (Face[nb].Orientation()==Face[nb-1].Orientation())
            orient= TopAbs::Reverse(orient);
        }
        if (!bordlibre) {
          Interfc=ChFi3d_FilCurveInDS(indcurv,indice,C2dint2,orient);
          DStr.ChangeShapeInterferences(indice).Append(Interfc);
        }
      }
    }

    if (checkShrink &&
	IsShrink(Ps,p1,p2,checkShrParam,isUShrink,Precision::Parametric(tolreached)))
    {
      shrink [nb-1] = 1;
      // store section face-chamf curve for previous SurfData
      // Suppose Fd and SDprev are parametrized similarly
      if (!isShrink) { // first time
	const ChFiDS_FaceInterference& Fi = SDprev->InterferenceOnS1();
	gp_Pnt2d UV = Fi.PCurveOnSurf()->Value(Fi.Parameter(isfirst));
	prevSDParam = isUShrink ? UV.X() : UV.Y();
      }
      gp_Pnt2d UV1=p2d1,UV2=p2d2;
      UV1.SetCoord(isUShrink ? 1 : 2, prevSDParam);
      UV2.SetCoord(isUShrink ? 1 : 2, prevSDParam);
      Standard_Real aTolreached;
      ChFi3d_ComputePCurv(Cc,UV1,UV2,Ps,
			  DStr.Surface(SDprev->Surf()).Surface(),
			  p1,p2,tolesp,aTolreached);
      TopOpeBRepDS_Curve& TCurv = DStr.ChangeCurve(indcurve[nb-1]);
      TCurv.Tolerance(Max(TCurv.Tolerance(),aTolreached));

      InterfPS[nb-1]=ChFi3d_FilCurveInDS(indcurve[nb-1],IsurfPrev,Ps,orcourbe);
      DStr.ChangeSurfaceInterferences(IsurfPrev).Append(InterfPS[nb-1]);

      if (isOnSame2) {
	midP2d = p2d2;
	midIpoint = indpoint2;
      }
      else if (!isShrink) {
	midP2d = p2d1;
	midIpoint = indpoint1;
      }
      isShrink = Standard_True;
    } // end if shrink

    
    indice=DStr.AddShape(Face[nb-1]);
    InterfPC[nb-1]=ChFi3d_FilCurveInDS(indcurve[nb-1],indice ,Pc,orien);
    if (!shrink [nb-1])
      InterfPS[nb-1]=ChFi3d_FilCurveInDS(indcurve[nb-1],Isurf,Ps,orcourbe);
    indpoint1=indpoint2;

  } // end loop on faces being intersected with ChFi

  
  if (isOnSame1) CV1.Reset();
  if (isOnSame2) CV2.Reset();

  for(nb=1;nb<=nbface;nb++) {
    Standard_Integer indice=DStr.AddShape(Face[nb-1]);
    DStr.ChangeShapeInterferences(indice).Append(InterfPC[nb-1]);
    if (!shrink [nb-1])
      DStr.ChangeSurfaceInterferences(Isurf).Append(InterfPS[nb-1]);
    if (!proledge[nb-1])
      DStr.ChangeShapeInterferences(Edge[nb-1]).Append(Interfedge[nb-1]);
  }
  DStr.ChangeShapeInterferences(Edge[nbface]).Append(Interfedge[nbface]);

  if (!isShrink)
    stripe->InDS(isfirst);
  else {
    // compute curves for !<isfirst> end of <Fd> and <isfirst> end of previous <SurfData>

    // for Fd
    //Bnd_Box box;
    gp_Pnt2d UV, UV1 = midP2d, UV2 = midP2d;
    if (isOnSame1) 
      UV = UV2 = Fi1.PCurveOnSurf()->Value(Fi1.Parameter(!isfirst));
    else 
      UV = UV1 = Fi2.PCurveOnSurf()->Value(Fi2.Parameter(!isfirst));
    Standard_Real aTolreached;
    Handle(Geom_Curve) C3d;
    Handle(Geom_Surface) aSurf = DStr.Surface(Fd->Surf()).Surface();
    //box.Add(aSurf->Value(UV.X(), UV.Y()));
    
    ChFi3d_ComputeArete(CV1,UV1,CV2,UV2,aSurf, // in 
			C3d,Ps,p1,p2,tolesp,tol2d,aTolreached,0); // out except tolers

    indpoint1 = indpoint2 = midIpoint;
    gp_Pnt point;
    if (isOnSame1) {
      point = C3d->Value(p2);
      TopOpeBRepDS_Point tpoint (point,aTolreached);
      indpoint2=DStr.AddPoint(tpoint);
      UV = Ps->Value(p2);
    } else {
      point = C3d->Value(p1);
      TopOpeBRepDS_Point tpoint (point,aTolreached);
      indpoint1=DStr.AddPoint(tpoint);
      UV = Ps->Value(p1);
    }
    //box.Add(point);
    //box.Add(aSurf->Value(UV.X(), UV.Y()));
    
    TopOpeBRepDS_Curve Crv = TopOpeBRepDS_Curve(C3d,aTolreached);
    Standard_Integer Icurv = DStr.AddCurve(Crv);
    Interfp1 = ChFi3d_FilPointInDS(TopAbs_FORWARD,Icurv,indpoint1,p1, Standard_False);
    Interfp2 = ChFi3d_FilPointInDS(TopAbs_REVERSED,Icurv,indpoint2,p2, Standard_False);
    Interfc = ChFi3d_FilCurveInDS(Icurv,Isurf,Ps,orcourbe);
    DStr.ChangeCurveInterferences(Icurv).Append(Interfp1);
    DStr.ChangeCurveInterferences(Icurv).Append(Interfp2);
    DStr.ChangeSurfaceInterferences(Isurf).Append(Interfc);

    // for SDprev
    aSurf = DStr.Surface(SDprev->Surf()).Surface();
    UV1.SetCoord(isUShrink ? 1 : 2, prevSDParam);
    UV2.SetCoord(isUShrink ? 1 : 2, prevSDParam);
    
    ChFi3d_ComputePCurv(C3d,UV1,UV2,Pc,aSurf,p1,p2,tolesp,aTolreached);
    
    Crv.Tolerance(Max(Crv.Tolerance(),aTolreached));
    Interfc= ChFi3d_FilCurveInDS (Icurv,IsurfPrev,Pc,TopAbs::Reverse(orcourbe));
    DStr.ChangeSurfaceInterferences(IsurfPrev).Append(Interfc);

    //UV = isOnSame1 ? UV2 : UV1;
    //box.Add(aSurf->Value(UV.X(), UV.Y()));
    //UV = Ps->Value(isOnSame1 ? p2 : p1);
    //box.Add(aSurf->Value(UV.X(), UV.Y()));
    //ChFi3d_SetPointTolerance(DStr,box, isOnSame1 ? indpoint2 : indpoint1);
    
    // to process properly this case in ChFi3d_FilDS()
    stripe->InDS(isfirst, 2);
    Fd->ChangeInterference(isOnSame1 ? 2 : 1).SetLineIndex(0);
    ChFiDS_CommonPoint& CPprev1 = SDprev->ChangeVertex( isfirst,isOnSame1 ? 2 : 1);
    ChFiDS_CommonPoint& CPlast1 = Fd->    ChangeVertex( isfirst,isOnSame1 ? 2 : 1);
    ChFiDS_CommonPoint& CPlast2 = Fd->    ChangeVertex(!isfirst,isOnSame1 ? 2 : 1);
    if (CPprev1.IsOnArc()) {
      CPlast1 = CPprev1;
      CPprev1.Reset();
      CPprev1.SetPoint(CPlast1.Point());
      CPlast2.Reset();
      CPlast2.SetPoint(CPlast1.Point());
    }

    // in shrink case, self intersection is possible at <midIpoint>,
    // eval its tolerance intersecting Ps and Pcurve at end.
    // Find end curves closest to shrinked part
    for (nb=0; nb < nbface; nb++)
      if (isOnSame1 ? shrink [nb+1] : !shrink [nb]) break;
    Handle(Geom_Curve)   Cend = DStr.Curve(indcurve[nb]).Curve();
    Handle(Geom2d_Curve) PCend = InterfPS[nb]->PCurve();
    // point near which self intersection may occure
    TopOpeBRepDS_Point& Pds = DStr.ChangePoint(midIpoint);
    const gp_Pnt& Pvert = Pds.Point();
    Standard_Real tol = Pds.Tolerance();

    Geom2dAdaptor_Curve PC1(Ps), PC2(PCend);
    Geom2dInt_GInter Intersector(PC1,PC2,Precision::PConfusion(),Precision::PConfusion());
    if (!Intersector.IsDone()) return;
    for (nb=1; nb <= Intersector.NbPoints(); nb++) {
      const IntRes2d_IntersectionPoint& ip = Intersector.Point(nb);
      gp_Pnt Pint = C3d->Value(ip.ParamOnFirst());
      tol = Max(tol, Pvert.Distance(Pint));
      Pint = Cend->Value(ip.ParamOnSecond());
      tol = Max(tol, Pvert.Distance(Pint));
    }
    for (nb=1; nb <= Intersector.NbSegments(); nb++) {
      const IntRes2d_IntersectionSegment& is = Intersector.Segment(nb);
      if (is.HasFirstPoint()) {
	const IntRes2d_IntersectionPoint& ip = is.FirstPoint();
	gp_Pnt Pint = C3d->Value(ip.ParamOnFirst());
	tol = Max(tol, Pvert.Distance(Pint));
	Pint = Cend->Value(ip.ParamOnSecond());
	tol = Max(tol, Pvert.Distance(Pint));
      }
      if (is.HasLastPoint()) {
	const IntRes2d_IntersectionPoint& ip = is.LastPoint();
	gp_Pnt Pint = C3d->Value(ip.ParamOnFirst());
	tol = Max(tol, Pvert.Distance(Pint));
	Pint = Cend->Value(ip.ParamOnSecond());
	tol = Max(tol, Pvert.Distance(Pint));
      }
    }
    Pds.Tolerance(tol);
  }
}

//  Modified by Sergey KHROMOV - Thu Apr 11 12:23:40 2002 Begin

//=======================================================================
//function : PerformMoreSurfdata
//purpose  :  determine intersections at end on several surfdata
//=======================================================================
void ChFi3d_Builder::PerformMoreSurfdata(const Standard_Integer Index)
{
  TopOpeBRepDS_DataStructure &DStr = myDS->ChangeDS();
  const ChFiDS_ListOfStripe  &aLOfStripe = myVDataMap(Index);
  Handle(ChFiDS_Stripe)       aStripe;
  Handle(ChFiDS_Spine)        aSpine;
  Standard_Real               aTol3d = 1.e-4;


  if (aLOfStripe.IsEmpty())
    return;

  aStripe = aLOfStripe.First();
  aSpine  = aStripe->Spine();

  ChFiDS_SequenceOfSurfData &aSeqSurfData =
                               aStripe->ChangeSetOfSurfData()->ChangeSequence();
  const TopoDS_Vertex       &aVtx         = myVDataMap.FindKey(Index);
  Standard_Integer           aSens        = 0;
  Standard_Integer           anInd        =
                               ChFi3d_IndexOfSurfData(aVtx,aStripe,aSens);
  Standard_Boolean           isFirst      = (aSens == 1);
  Standard_Integer           anIndPrev;
  Handle(ChFiDS_SurfData)    aSurfData;
  ChFiDS_CommonPoint         aCP1;
  ChFiDS_CommonPoint         aCP2;

  aSurfData = aSeqSurfData.Value(anInd);

  aCP1 = aSurfData->Vertex(isFirst,1);
  aCP2 = aSurfData->Vertex(isFirst,2);

  Handle(Geom_Surface) aSurfPrev;
  Handle(Geom_Surface) aSurf;
  TopoDS_Face          aFace;
  TopoDS_Face          aNeighborFace;

  FindFace(aVtx, aCP1, aCP2, aFace);
  aSurfPrev = BRep_Tool::Surface(aFace);

  if (aSens==1) anIndPrev=anInd+1;
  else  anIndPrev=anInd-1;

  TopoDS_Edge                        anArc1;
  TopoDS_Edge                        anArc2;
  TopTools_ListIteratorOfListOfShape anIter(myVEMap(aVtx));
  Standard_Boolean                   isFound = Standard_False;

  for(; anIter.More() && !isFound; anIter.Next()) {
    anArc1 = TopoDS::Edge(anIter.Value());

    if (containE(aFace, anArc1))
      isFound = Standard_True;
  }

  isFound = Standard_False;
  anIter.Initialize(myVEMap(aVtx));

  for(; anIter.More() && !isFound; anIter.Next()) {
    anArc2 = TopoDS::Edge(anIter.Value());

    if (containE(aFace,anArc2) && !anArc2.IsSame(anArc1))
      isFound = Standard_True;
  }

  // determination of common points aCP1onArc, aCP2onArc and aCP2NotonArc
  // aCP1onArc    is the point on arc of index anInd
  // aCP2onArc    is the point on arc of index anIndPrev
  // aCP2NotonArc is the point of index anIndPrev which is not on arc.

  Standard_Boolean   is1stCP1OnArc;
  Standard_Boolean   is2ndCP1OnArc;
  ChFiDS_CommonPoint aCP1onArc;
  ChFiDS_CommonPoint aCP2onArc;
  ChFiDS_CommonPoint aCP2NotonArc;

  aSurfData = aSeqSurfData.Value(anIndPrev);
  aCP1      = aSurfData->Vertex(isFirst,1);
  aCP2      = aSurfData->Vertex(isFirst,2);

  if (aCP1.IsOnArc() &&
      (aCP1.Arc().IsSame(anArc1) || aCP1.Arc().IsSame(anArc2))) {
      aCP2onArc     = aCP1;
      aCP2NotonArc  = aCP2;
      is2ndCP1OnArc = Standard_True;
  } else if (aCP2.IsOnArc() &&
	     (aCP2.Arc().IsSame(anArc1) || aCP2.Arc().IsSame(anArc2))) {
      aCP2onArc     = aCP2;
      aCP2NotonArc  = aCP1;
      is2ndCP1OnArc = Standard_False;
  } else
    return;

  aSurfData = aSeqSurfData.Value(anInd);
  aCP1      = aSurfData->Vertex(isFirst,1);
  aCP2      = aSurfData->Vertex(isFirst,2);

  if (aCP1.Point().Distance(aCP2onArc.Point()) <= aTol3d){
    aCP1onArc     = aCP2;
    is1stCP1OnArc = Standard_False;
  }
  else {
    aCP1onArc     = aCP1;
    is1stCP1OnArc = Standard_True;
  }

  if (!aCP1onArc.IsOnArc())
    return;

// determination of neighbor surface
  Standard_Integer indSurface;
  if (is1stCP1OnArc)
    indSurface = myListStripe.First()->SetOfSurfData()->Value(anInd)->IndexOfS1();
  else
    indSurface = myListStripe.First()->SetOfSurfData()->Value(anInd)->IndexOfS2();

  aNeighborFace = TopoDS::Face(myDS->Shape(indSurface));

// calculation of intersections
  Handle(Geom_Curve)   aCracc;
  Handle(Geom2d_Curve) aPCurv1;
  Standard_Real        aParf;
  Standard_Real        aParl;
  Standard_Real        aTolReached;

  aSurfData = aSeqSurfData.Value(anInd);

  if (isFirst)
    ChFi3d_ComputeArete(aSurfData->VertexLastOnS1(),
			aSurfData->InterferenceOnS1().PCurveOnSurf()->
			Value(aSurfData->InterferenceOnS1().LastParameter()),
			aSurfData->VertexLastOnS2(),
			aSurfData->InterferenceOnS2().PCurveOnSurf()->
			Value(aSurfData->InterferenceOnS2().LastParameter()),
			DStr.Surface(aSurfData->Surf()).Surface(),aCracc,aPCurv1,
			aParf,aParl,aTol3d,tol2d,aTolReached,0);
  else
    ChFi3d_ComputeArete(aSurfData->VertexFirstOnS1(),
			aSurfData->InterferenceOnS1().PCurveOnSurf()->
			Value(aSurfData->InterferenceOnS1().FirstParameter()),
			aSurfData->VertexFirstOnS2(),
			aSurfData->InterferenceOnS2().PCurveOnSurf()->
			Value(aSurfData->InterferenceOnS2().FirstParameter()),
			DStr.Surface(aSurfData->Surf()).Surface(),aCracc,aPCurv1,
			aParf,aParl,aTol3d,tol2d,aTolReached,0);

// calculation of the index of the line on anInd.
// aPClineOnSurf is the pcurve on anInd.
// aPClineOnFace is the pcurve on face.
  ChFiDS_FaceInterference  aFI;

  if (is1stCP1OnArc)
    aFI = aSurfData->InterferenceOnS1();
  else
    aFI = aSurfData->InterferenceOnS2();

  Handle(Geom_Curve)   aCline;
  Handle(Geom2d_Curve) aPClineOnSurf;
  Handle(Geom2d_Curve) aPClineOnFace;
  Standard_Integer     indLine;

  indLine       = aFI.LineIndex();
  aCline        = DStr.Curve(aFI.LineIndex()).Curve();
  aPClineOnSurf = aFI.PCurveOnSurf();
  aPClineOnFace = aFI.PCurveOnFace();

// intersection between the SurfData number anInd and the Face aFace.
// Obtaining of curves aCint1, aPCint11 and aPCint12.
  aSurf = DStr.Surface(aSurfData->Surf()).Surface();

  GeomInt_IntSS                anInterSS(aSurfPrev,aSurf,1.e-7,1,1,1);
  Handle(Geom_Curve)           aCint1;
  Handle(Geom2d_Curve)         aPCint11;
  Handle(Geom2d_Curve)         aPCint12;
  Handle(GeomAdaptor_HSurface) H1 = new GeomAdaptor_HSurface(aSurfPrev);
  Handle(GeomAdaptor_HSurface) H2 = new GeomAdaptor_HSurface(aSurf);
  Standard_Real                aTolex1=0.;
  Standard_Integer             i;
  gp_Pnt                       aPext1;
  gp_Pnt                       aPext2;
  gp_Pnt                       aPext;
  Standard_Boolean             isPextFound;


  if (!anInterSS.IsDone())
    return;

  isFound = Standard_False;

  for (i = 1; i <= anInterSS.NbLines() && !isFound; i++) {
    aCint1   = anInterSS.Line(i);
    aPCint11 = anInterSS.LineOnS1(i);
    aPCint12 = anInterSS.LineOnS2(i);
    aTolex1  = ChFi3d_EvalTolReached(H1, aPCint11, H2, aPCint12, aCint1);

    aCint1->D0(aCint1->FirstParameter(), aPext1);
    aCint1->D0(aCint1->LastParameter(),  aPext2);

//  Modified by skv - Mon Jun  7 18:38:57 2004 OCC5898 Begin
//     if (aPext1.Distance(aCP1onArc.Point()) <= aTol3d ||
// 	aPext2.Distance(aCP1onArc.Point()))
    if (aPext1.Distance(aCP1onArc.Point()) <= aTol3d ||
	aPext2.Distance(aCP1onArc.Point()) <= aTol3d)
//  Modified by skv - Mon Jun  7 18:38:58 2004 OCC5898 End
      isFound = Standard_True;
  }

  if (!isFound)
    return;

  if (aPext1.Distance(aCP2onArc.Point()) > aTol3d &&
      aPext1.Distance(aCP1onArc.Point()) > aTol3d) {
    aPext       = aPext1;
    isPextFound = Standard_True;
  } else if (aPext2.Distance(aCP2onArc.Point()) > aTol3d &&
	     aPext2.Distance(aCP1onArc.Point()) > aTol3d) {
    aPext       = aPext2;
    isPextFound = Standard_True;
  } else {
    isPextFound = Standard_False;
  }


  Standard_Boolean  isDoSecondSection = Standard_False;
  Standard_Real     aPar=0.;

  if (isPextFound) {
    GeomAdaptor_Curve aCad(aCracc);
    Extrema_ExtPC     anExt(aPext, aCad, aTol3d);

    if (!anExt.IsDone())
      return;

    isFound = Standard_False;
    for (i = 1; i <= anExt.NbExt() && !isFound; i++) {
      if (anExt.IsMin(i)) {
	gp_Pnt aProjPnt = anExt.Point(i).Value();

	if (aPext.Distance(aProjPnt) <= aTol3d) {
	  aPar              = anExt.Point(i).Parameter();
	  isDoSecondSection = Standard_True;
	}
      }
    }
  }

  Handle(Geom_Curve) aTrCracc;
  TopAbs_Orientation anOrSD1;
  TopAbs_Orientation anOrSD2;
  Standard_Integer   indShape;

  anOrSD1   = aSurfData->Orientation();
  aSurfData = aSeqSurfData.Value(anIndPrev);
  anOrSD2   = aSurfData->Orientation();
  aSurf     = DStr.Surface(aSurfData->Surf()).Surface();

// The following variables will be used if isDoSecondSection is true
  Handle(Geom_Curve)           aCint2;
  Handle(Geom2d_Curve)         aPCint21;
  Handle(Geom2d_Curve)         aPCint22;
  Standard_Real                aTolex2=0.;

  if (isDoSecondSection) {
    Standard_Real aPar1;

    aCracc->D0(aCracc->FirstParameter(), aPext1);

    if (aPext1.Distance(aCP2NotonArc.Point()) <= aTol3d)
      aPar1 = aCracc->FirstParameter();
    else
      aPar1 = aCracc->LastParameter();

    if (aPar1 < aPar)
      aTrCracc = new Geom_TrimmedCurve (aCracc, aPar1, aPar);
    else
      aTrCracc = new Geom_TrimmedCurve (aCracc, aPar,  aPar1);

// Second section
    GeomInt_IntSS anInterSS2(aSurfPrev,aSurf,1.e-7,1,1,1);

    if (!anInterSS2.IsDone())
      return;

    H1 = new GeomAdaptor_HSurface(aSurfPrev);
    H2 = new GeomAdaptor_HSurface(aSurf);

    isFound = Standard_False;

    for (i = 1; i <= anInterSS2.NbLines() && !isFound; i++) {
      aCint2   = anInterSS2.Line(i);
      aPCint21 = anInterSS2.LineOnS1(i);
      aPCint22 = anInterSS2.LineOnS2(i);
      aTolex2  = ChFi3d_EvalTolReached(H1, aPCint21, H2, aPCint22, aCint2);

      aCint2->D0(aCint2->FirstParameter(), aPext1);
      aCint2->D0(aCint2->LastParameter(),  aPext2);

      if (aPext1.Distance(aCP2onArc.Point()) <= aTol3d ||
	  aPext2.Distance(aCP2onArc.Point()) <= aTol3d)
	isFound = Standard_True;
    }

    if (!isFound)
      return;

  } else {
    aTrCracc = new Geom_TrimmedCurve(aCracc,
				     aCracc->FirstParameter(),
				     aCracc->LastParameter());
  }

// Storage of the data structure

// calculation of the orientation of line of surfdata number
// anIndPrev which contains aCP2onArc

  Handle(Geom2d_Curve) aPCraccS = GeomProjLib::Curve2d(aTrCracc,aSurf);

  if (is2ndCP1OnArc) {
    aFI      = aSurfData->InterferenceOnS1();
    indShape = aSurfData->IndexOfS1();
  } else {
    aFI      = aSurfData->InterferenceOnS2();
    indShape = aSurfData->IndexOfS2();
  }

  if (indShape <= 0)
    return;



  TopAbs_Orientation aCurOrient;

  aCurOrient = DStr.Shape(indShape).Orientation();
  aCurOrient = TopAbs::Compose(aCurOrient, aSurfData->Orientation());
  aCurOrient = TopAbs::Compose(TopAbs::Reverse(aFI.Transition()), aCurOrient);


// Filling the data structure
  aSurfData   = aSeqSurfData.Value(anInd);

  TopOpeBRepDS_Point aPtCP1(aCP1onArc.Point(),aCP1onArc.Tolerance());
  Standard_Integer   indCP1onArc = DStr.AddPoint(aPtCP1);
  Standard_Integer   indSurf1    = aSurfData->Surf();
  Standard_Integer   indArc1     = DStr.AddShape(aCP1onArc.Arc());
  Standard_Integer   indSol      = aStripe->SolidIndex();

  Handle (TopOpeBRepDS_CurvePointInterference) anInterfp1;
  Handle (TopOpeBRepDS_CurvePointInterference) anInterfp2;

  anInterfp1= ChFi3d_FilPointInDS(aCP1onArc.TransitionOnArc(), indArc1,
				  indCP1onArc, aCP1onArc.ParameterOnArc());
  DStr.ChangeShapeInterferences(aCP1onArc.Arc()).Append(anInterfp1);

  TopOpeBRepDS_ListOfInterference &SolidInterfs  =
                                   DStr.ChangeShapeInterferences(indSol);
  Handle(TopOpeBRepDS_SolidSurfaceInterference) SSI =
    new TopOpeBRepDS_SolidSurfaceInterference
                                      (TopOpeBRepDS_Transition(anOrSD1),
				       TopOpeBRepDS_SOLID, indSol,
				       TopOpeBRepDS_SURFACE, indSurf1);
  SolidInterfs.Append(SSI);

// deletion of Surface Data.
  aSeqSurfData.Remove(anInd);

  if (!isFirst)
    anInd--;

  aSurfData = aSeqSurfData.Value(anInd);

// definition of indices of common points in Data Structure

  Standard_Integer indCP2onArc;
  Standard_Integer indCP2NotonArc;

  if (is2ndCP1OnArc) {
    aStripe->SetIndexPoint(ChFi3d_IndexPointInDS(aCP2onArc,   DStr),isFirst,1);
    aStripe->SetIndexPoint(ChFi3d_IndexPointInDS(aCP2NotonArc,DStr),isFirst,2);

    if (isFirst) {
      indCP2onArc    = aStripe->IndexFirstPointOnS1();
      indCP2NotonArc = aStripe->IndexFirstPointOnS2();
    } else {
      indCP2onArc    = aStripe->IndexLastPointOnS1();
      indCP2NotonArc = aStripe->IndexLastPointOnS2();
    }
  } else {
    aStripe->SetIndexPoint(ChFi3d_IndexPointInDS(aCP2onArc,   DStr),isFirst,2);
    aStripe->SetIndexPoint(ChFi3d_IndexPointInDS(aCP2NotonArc,DStr),isFirst,1);

    if (isFirst) {
      indCP2onArc    = aStripe->IndexFirstPointOnS2();
      indCP2NotonArc = aStripe->IndexFirstPointOnS1();
    }
    else {
      indCP2onArc    = aStripe->IndexLastPointOnS2();
      indCP2NotonArc = aStripe->IndexLastPointOnS1();
    }
  }

  Standard_Integer indPoint1;
  Standard_Integer indPoint2;
  gp_Pnt           aPoint1;
  gp_Pnt           aPoint2;

  if (is2ndCP1OnArc)  {
    aFI      = aSurfData->InterferenceOnS1();
    indShape = aSurfData->IndexOfS1();
  } else {
    aFI      = aSurfData->InterferenceOnS2();
    indShape = aSurfData->IndexOfS2();
  }

  gp_Pnt2d                                       aP2d;
  Handle (TopOpeBRepDS_SurfaceCurveInterference) anInterfc;
  TopAbs_Orientation                             anOrSurf = aCurOrient;
  TopAbs_Orientation                             anOrFace = aFace.Orientation();
  Standard_Integer                               indaFace = DStr.AddShape(aFace);
  Standard_Integer                               indPoint = indCP2onArc;
  Standard_Integer                               indCurve;

  aFI.PCurveOnFace()->D0(aFI.LastParameter(), aP2d);
  Handle(Geom_Surface) Stemp2 =
                       BRep_Tool::Surface(TopoDS::Face(DStr.Shape(indShape)));
  Stemp2->D0(aP2d.X(), aP2d.Y(), aPoint2);
  aFI.PCurveOnFace()->D0(aFI.FirstParameter(), aP2d);
  Stemp2->D0(aP2d.X(), aP2d.Y(), aPoint1);

  if (isDoSecondSection) {
    TopOpeBRepDS_Point tpoint(aPext,  aTolex2);
    TopOpeBRepDS_Curve tcint2(aCint2, aTolex2);

    indPoint = DStr.AddPoint(tpoint);
    indCurve = DStr.AddCurve(tcint2);

    aCint2->D0(aCint2->FirstParameter(), aPext1);
    aCint2->D0(aCint2->LastParameter(),  aPext2);

    if (aPext1.Distance(aPext) <= aTol3d){
      indPoint1 = indPoint;
      indPoint2 = indCP2onArc;
    } else {
      indPoint1 = indCP2onArc;
      indPoint2 = indPoint;
    }

// define the orientation of aCint2
    if (aPext1.Distance(aPoint2) > aTol3d && aPext2.Distance(aPoint1) > aTol3d)
      anOrSurf = TopAbs::Reverse(anOrSurf);

// ---------------------------------------------------------------
// storage of aCint2
    anInterfp1 = ChFi3d_FilPointInDS(TopAbs_FORWARD, indCurve,
				     indPoint1, aCint2->FirstParameter());
    anInterfp2 = ChFi3d_FilPointInDS(TopAbs_REVERSED, indCurve,
				     indPoint2, aCint2->LastParameter());
    DStr.ChangeCurveInterferences(indCurve).Append(anInterfp1);
    DStr.ChangeCurveInterferences(indCurve).Append(anInterfp2);

  // interference of aCint2 on the SurfData number anIndPrev
    anInterfc = ChFi3d_FilCurveInDS(indCurve, aSurfData->Surf(),
				    aPCint22, anOrSurf);

    DStr.ChangeSurfaceInterferences(aSurfData->Surf()).Append(anInterfc);
  // interference of aCint2 on aFace

    if (anOrFace == anOrSD2)
      anOrFace = TopAbs::Reverse(anOrSurf);
    else
      anOrFace = anOrSurf;

    anInterfc = ChFi3d_FilCurveInDS(indCurve, indaFace, aPCint21, anOrFace);
    DStr.ChangeShapeInterferences(indaFace).Append(anInterfc);
  }

  aTrCracc->D0(aTrCracc->FirstParameter(), aPext1);
  aTrCracc->D0(aTrCracc->LastParameter(),  aPext2);
  if (aPext1.Distance(aCP2NotonArc.Point()) <= aTol3d){
    indPoint1 = indCP2NotonArc;
    indPoint2 = indPoint;
  } else {
    indPoint1 = indPoint;
    indPoint2 = indCP2NotonArc;
  }

// Define the orientation of aTrCracc
  Standard_Boolean isToReverse;
  gp_Pnt           aP1;
  gp_Pnt           aP2;
  gp_Pnt           aP3;
  gp_Pnt           aP4;


  if (isDoSecondSection) {
    aTrCracc->D0(aTrCracc->FirstParameter(), aP1);
    aTrCracc->D0(aTrCracc->LastParameter(),  aP2);
    aCint2->D0(aCint2->FirstParameter(), aP3);
    aCint2->D0(aCint2->LastParameter(),  aP4);
    isToReverse = (aP1.Distance(aP4) > aTol3d && aP2.Distance(aP3) > aTol3d);
  } else {
    isToReverse = (aPext1.Distance(aPoint2) > aTol3d &&
		   aPext2.Distance(aPoint1) > aTol3d);
  }

  if (isToReverse)
    anOrSurf = TopAbs::Reverse(anOrSurf);

// ---------------------------------------------------------------
// storage of aTrCracc
  TopOpeBRepDS_Curve tct2(aTrCracc, aTolReached);

  indCurve = DStr.AddCurve(tct2);
  anInterfp1 = ChFi3d_FilPointInDS(TopAbs_FORWARD,indCurve,
				   indPoint1, aTrCracc->FirstParameter());
  anInterfp2 = ChFi3d_FilPointInDS(TopAbs_REVERSED,indCurve,
				   indPoint2, aTrCracc->LastParameter());
  DStr.ChangeCurveInterferences(indCurve).Append(anInterfp1);
  DStr.ChangeCurveInterferences(indCurve).Append(anInterfp2);

  // interference of aTrCracc on the SurfData number anIndPrev

  anInterfc = ChFi3d_FilCurveInDS(indCurve,aSurfData->Surf(),aPCraccS, anOrSurf);
  DStr.ChangeSurfaceInterferences(aSurfData->Surf()).Append(anInterfc);
  aStripe->InDS(isFirst);

  // interference of aTrCracc on the SurfData number anInd
  if (anOrSD1 == anOrSD2)
    anOrSurf = TopAbs::Reverse(anOrSurf);

  anInterfc = ChFi3d_FilCurveInDS(indCurve, indSurf1, aPCurv1, anOrSurf);
  DStr.ChangeSurfaceInterferences(indSurf1).Append(anInterfc);

// ---------------------------------------------------------------
// storage of aCint1

  aCint1->D0(aCint1->FirstParameter(),aPext1);
  if (aPext1.Distance(aCP1onArc.Point()) <= aTol3d){
    indPoint1 = indCP1onArc;
    indPoint2 = indPoint;
  } else {
    indPoint1 = indPoint;
    indPoint2 = indCP1onArc;
  }

  //  definition of the orientation of aCint1

  aCint1->D0(aCint1->FirstParameter(), aP1);
  aCint1->D0(aCint1->LastParameter(),  aP2);
  aTrCracc->D0(aTrCracc->FirstParameter(), aP3);
  aTrCracc->D0(aTrCracc->LastParameter(),  aP4);

  if (aP1.Distance(aP4) > aTol3d && aP2.Distance(aP3) > aTol3d)
    anOrSurf=TopAbs::Reverse(anOrSurf);

  TopOpeBRepDS_Curve aTCint1(aCint1, aTolex1);
  indCurve= DStr.AddCurve(aTCint1);
  anInterfp1 = ChFi3d_FilPointInDS(TopAbs_FORWARD, indCurve,
				   indPoint1, aCint1->FirstParameter());
  anInterfp2 = ChFi3d_FilPointInDS(TopAbs_REVERSED, indCurve,
				   indPoint2, aCint1->LastParameter());
  DStr.ChangeCurveInterferences(indCurve).Append(anInterfp1);
  DStr.ChangeCurveInterferences(indCurve).Append(anInterfp2);

  // interference of aCint1 on the SurfData number anInd

  anInterfc = ChFi3d_FilCurveInDS(indCurve, indSurf1, aPCint12, anOrSurf);
  DStr.ChangeSurfaceInterferences(indSurf1).Append(anInterfc);

  // interference of aCint1 on aFace

  anOrFace = aFace.Orientation();

  if (anOrFace == anOrSD1)
    anOrFace = TopAbs::Reverse(anOrSurf);
  else
    anOrFace = anOrSurf;

  anInterfc = ChFi3d_FilCurveInDS(indCurve, indaFace, aPCint11, anOrFace);
  DStr.ChangeShapeInterferences(indaFace).Append(anInterfc);
// ---------------------------------------------------------------
// storage of aCline passing through aCP1onArc and aCP2NotonArc

  Handle(Geom_Curve) aTrCline   =
                     new Geom_TrimmedCurve(aCline, aCline->FirstParameter(),
					           aCline->LastParameter());
  Standard_Real      aTolerance = DStr.Curve(indLine).Tolerance();
  TopOpeBRepDS_Curve aTct3(aTrCline, aTolerance);

  indCurve = DStr.AddCurve(aTct3);

  aTrCline->D0(aTrCline->FirstParameter(),aPext1);

  if (aPext1.Distance(aCP1onArc.Point()) < aTol3d) {
    indPoint1 = indCP1onArc;
    indPoint2 = indCP2NotonArc;
  } else {
    indPoint1 = indCP2NotonArc;
    indPoint2 = indCP1onArc;
  }
  //  definition of the orientation of aTrCline

  aTrCline->D0(aTrCline->FirstParameter(), aP1);
  aTrCline->D0(aTrCline->LastParameter(),  aP2);
  aCint1->D0(aCint1->FirstParameter(), aP3);
  aCint1->D0(aCint1->LastParameter(),  aP4);

  if (aP1.Distance(aP4) > aTol3d && aP2.Distance(aP3) > aTol3d)
    anOrSurf = TopAbs::Reverse(anOrSurf);

  anInterfp1 = ChFi3d_FilPointInDS(TopAbs_FORWARD,indCurve,
				   indPoint1,aTrCline->FirstParameter());
  anInterfp2 = ChFi3d_FilPointInDS(TopAbs_REVERSED,indCurve,
				   indPoint2,aTrCline->LastParameter());
  DStr.ChangeCurveInterferences(indCurve).Append(anInterfp1);
  DStr.ChangeCurveInterferences(indCurve).Append(anInterfp2);

  // interference of aTrCline on the SurfData number anInd

  anInterfc = ChFi3d_FilCurveInDS(indCurve, indSurf1, aPClineOnSurf, anOrSurf);
  DStr.ChangeSurfaceInterferences(indSurf1).Append(anInterfc);

  // interference de ctlin par rapport a Fvoisin
  indShape = DStr.AddShape(aNeighborFace);
  anOrFace = aNeighborFace.Orientation();

  if (anOrFace == anOrSD1)
    anOrFace = TopAbs::Reverse(anOrSurf);
  else
    anOrFace = anOrSurf;

  anInterfc = ChFi3d_FilCurveInDS(indCurve, indShape, aPClineOnFace, anOrFace);
  DStr.ChangeShapeInterferences(indShape).Append(anInterfc);
}
//  Modified by Sergey KHROMOV - Thu Apr 11 12:23:40 2002 End

//==============================================================
//function : FindFace
//purpose  : attention it works only if there is only one common face 
//           between P1,P2,V
//===========================================================


Standard_Boolean ChFi3d_Builder::FindFace(const TopoDS_Vertex& V,
					  const ChFiDS_CommonPoint& P1,
					  const ChFiDS_CommonPoint& P2,
					  TopoDS_Face& Fv) const
{
  TopoDS_Face Favoid;
  return FindFace(V,P1,P2,Fv,Favoid);
}

Standard_Boolean ChFi3d_Builder::FindFace(const TopoDS_Vertex& V,
					  const ChFiDS_CommonPoint& P1,
					  const ChFiDS_CommonPoint& P2,
					  TopoDS_Face& Fv,
					  const TopoDS_Face& Favoid) const
{
  if (P1.IsVertex() || P2.IsVertex()) {
#ifdef DEB
    cout<<"change of face on vertex"<<endl;
#endif
  }
  if (!(P1.IsOnArc() && P2.IsOnArc())) {
    return Standard_False;
  }
  TopTools_ListIteratorOfListOfShape It,Jt;
  Standard_Boolean Found = Standard_False, ContainsV = Standard_False;
  for(It.Initialize(myEFMap(P1.Arc()));It.More() && !Found;It.Next()) {
    Fv = TopoDS::Face(It.Value());
    if(!Fv.IsSame(Favoid)){
      for(Jt.Initialize(myEFMap(P2.Arc()));Jt.More() && !Found ;Jt.Next()) {
	if (TopoDS::Face(Jt.Value()).IsSame(Fv)) Found = Standard_True;
      }
    }
  }
  if (Found) {
    for(It.Initialize(myVFMap(V));It.More();It.Next()) {
      if (TopoDS::Face(It.Value()).IsSame(Fv)) {
	ContainsV = Standard_True;
	break;
      }
    }
  }
#ifdef DEB
  if(!ContainsV){
    cout<<"FindFace : the extremity of the spine is not in the end face"<<endl;
  }
#endif
  return Found;
}

//=======================================================================
//function : MoreSurfdata
//purpose  : detects if the intersection at end concerns several Surfdata
//=======================================================================
Standard_Boolean ChFi3d_Builder::MoreSurfdata(const Standard_Integer Index) const
{
  // intersection at end is created on several surfdata if :
  // - the number of surfdata concerning the vertex is more than 1.
  // - and if the last but one surfdata has one of commonpoints on one of 
  // two arcs, which constitute the intersections of the face at end and of the fillet

  ChFiDS_ListIteratorOfListOfStripe It;
  It.Initialize(myVDataMap(Index));
  Handle(ChFiDS_Stripe)& stripe = It.Value();
  ChFiDS_SequenceOfSurfData& SeqFil =
    stripe->ChangeSetOfSurfData()->ChangeSequence();
  const TopoDS_Vertex& Vtx = myVDataMap.FindKey(Index);
  Standard_Integer sens = 0;
  Standard_Integer num = ChFi3d_IndexOfSurfData(Vtx,stripe,sens);
  Standard_Boolean isfirst = (sens == 1);
  Handle(ChFiDS_SurfData)& Fd = SeqFil.ChangeValue(num);
  ChFiDS_CommonPoint& CV1 = Fd->ChangeVertex(isfirst,1);
  ChFiDS_CommonPoint& CV2 = Fd->ChangeVertex(isfirst,2);

  Standard_Integer num1,num2,nbsurf;
  TopoDS_Face Fv;
  Standard_Boolean inters,oksurf;
  nbsurf= stripe->SetOfSurfData()->Length();
  // Fv is the face at end
  inters = FindFace(Vtx,CV1,CV2,Fv);
  if (sens==1)  {
    num1=1;
    num2=num1+1;
  }
  else {
    num1=nbsurf;
    num2=num1-1;
  }

  oksurf=Standard_False;

  if (nbsurf!=1 && inters) {

    // determination of arc1 and arc2 intersection of the fillet and the face at end

    TopoDS_Edge arc1,arc2;
    TopTools_ListIteratorOfListOfShape ItE;
    Standard_Boolean trouve=Standard_False;
    for(ItE.Initialize(myVEMap(Vtx));ItE.More()&&!trouve;ItE.Next()) {
      arc1=TopoDS::Edge(ItE.Value());
      if (containE(Fv,arc1)) trouve=Standard_True;
    }
    trouve=Standard_False;
    for(ItE.Initialize(myVEMap(Vtx));ItE.More()&&!trouve;ItE.Next()) {
      arc2=TopoDS::Edge(ItE.Value());
      if (containE(Fv,arc2)&& !arc2.IsSame(arc1)) trouve=Standard_True;
    }

    Handle(ChFiDS_SurfData) Fd1 = SeqFil.ChangeValue(num2);
    ChFiDS_CommonPoint& CV3 = Fd1->ChangeVertex(isfirst,1);
    ChFiDS_CommonPoint& CV4 = Fd1->ChangeVertex(isfirst,2);

    if (CV3.IsOnArc()) {
      if (CV3.Arc().IsSame(arc1) ){
	if (CV1.Point().Distance(CV3.Point())<1.e-4)
	  oksurf=Standard_True;
      }
      else if (CV3.Arc().IsSame(arc2)){
        if (CV2.Point().Distance(CV3.Point())<1.e-4)
	  oksurf=Standard_True;
      }
    }

    if (CV4.IsOnArc()) {
      if (CV1.Point().Distance(CV4.Point())<1.e-4)
	oksurf=Standard_True;
      else if  (CV4.Arc().IsSame(arc2)){
	if (CV2.Point().Distance(CV4.Point())<1.e-4)
	  oksurf=Standard_True;
      }
    }
  }
  return oksurf;
}


//Case of fillets on top with 4 edges, one of them is on the same geometry as the edgeof the fillet


void ChFi3d_Builder::IntersectMoreCorner(const Standard_Integer Index)
{
  TopOpeBRepDS_DataStructure& DStr = myDS->ChangeDS();

#ifdef DEB
  OSD_Chronometer ch;// init perf pour PerformSetOfKPart
#endif
  // The fillet is returned,
  ChFiDS_ListIteratorOfListOfStripe StrIt;
  StrIt.Initialize(myVDataMap(Index));
  Handle(ChFiDS_Stripe) stripe = StrIt.Value();
  const Handle(ChFiDS_Spine) spine = stripe->Spine();
  ChFiDS_SequenceOfSurfData& SeqFil =
    stripe->ChangeSetOfSurfData()->ChangeSequence();
  // the top,
  const TopoDS_Vertex& Vtx = myVDataMap.FindKey(Index);
  // the SurfData concerned and its CommonPoints,
  Standard_Integer sens = 0;

  // Choose the proper SurfData
  Standard_Integer num = ChFi3d_IndexOfSurfData(Vtx,stripe,sens);
  Standard_Boolean isfirst = (sens == 1);
  if (isfirst) {
    for (; num<SeqFil.Length() && (
	 (SeqFil.Value(num)->IndexOfS1()==0) ||
	 (SeqFil.Value(num)->IndexOfS2()==0) ); ) {
      SeqFil.Remove(num); // The surplus is removed
    }
  }
  else {
   for (; num>1 && (
	 (SeqFil.Value(num)->IndexOfS1()==0) ||
	 (SeqFil.Value(num)->IndexOfS2()==0) ); ) {
     SeqFil.Remove(num);// The surplus is removed
     num--;
    }
  }

  Handle(ChFiDS_SurfData)& Fd = SeqFil.ChangeValue(num);
  ChFiDS_CommonPoint& CV1 = Fd->ChangeVertex(isfirst,1);
  ChFiDS_CommonPoint& CV2 = Fd->ChangeVertex(isfirst,2);
  //To evaluate the cloud of new points.
  Bnd_Box box1,box2;

  // The cases of cap are processed separately from intersection.
  // ----------------------------------------------------------

  TopoDS_Face Fv,Fad,Fop,Fopbis;
  TopoDS_Edge Arcpiv,Arcprol,Arcspine,Arcprolbis;
  if(isfirst) Arcspine = spine->Edges(1);
  else Arcspine = spine->Edges(spine->NbEdges());
  TopAbs_Orientation OArcprolbis = TopAbs_FORWARD;
#ifndef DEB
  TopAbs_Orientation OArcprolv = TopAbs_FORWARD, OArcprolop = TopAbs_FORWARD;
#else
  TopAbs_Orientation OArcprolv, OArcprolop;
#endif
  Standard_Integer ICurve;
  Handle(BRepAdaptor_HSurface) HBs  = new BRepAdaptor_HSurface();
  Handle(BRepAdaptor_HSurface) HBad = new BRepAdaptor_HSurface();
  Handle(BRepAdaptor_HSurface) HBop = new BRepAdaptor_HSurface();
  BRepAdaptor_Surface& Bs  = HBs->ChangeSurface();
  BRepAdaptor_Surface& Bad = HBad->ChangeSurface();
  BRepAdaptor_Surface& Bop = HBop->ChangeSurface();
  Handle(Geom_Curve) Cc;
  Handle(Geom2d_Curve) Pc,Ps;
  Standard_Real Ubid,Vbid;//,mu,Mu,mv,Mv;
#ifndef DEB
  Standard_Real Udeb = 0.,Ufin = 0.;
#else
  Standard_Real Udeb,Ufin;
#endif
  //gp_Pnt2d UVf1,UVl1,UVf2,UVl2;
  //Standard_Real Du,Dv,Step;
  Standard_Boolean inters = Standard_True;
  Standard_Integer IFadArc = 1, IFopArc = 2;
  Fop = TopoDS::Face(DStr.Shape(Fd->Index(IFopArc)));
  TopExp_Explorer ex;

#ifdef DEB
  ChFi3d_InitChron(ch); // init perf condition
#endif
  {
    if(!CV1.IsOnArc() && !CV2.IsOnArc())
      Standard_Failure::Raise("Corner intersmore : no point on arc");
    else if(CV1.IsOnArc() && CV2.IsOnArc()){
      Standard_Boolean sur2 = 0;
      for(ex.Init(CV1.Arc(),TopAbs_VERTEX); ex.More(); ex.Next()){
	if(Vtx.IsSame(ex.Current())) {
	  break;
	}
      }
      for(ex.Init(CV2.Arc(),TopAbs_VERTEX); ex.More(); ex.Next()){
	if(Vtx.IsSame(ex.Current())){
	  sur2 = 1;
	  break;
	}
      }
      if(sur2) IFadArc = 2;
    }
    else if(CV2.IsOnArc()) IFadArc = 2;
    IFopArc = 3-IFadArc;

    Arcpiv = Fd->Vertex(isfirst,IFadArc).Arc();
    Fad = TopoDS::Face(DStr.Shape(Fd->Index(IFadArc)));
    Fop = TopoDS::Face(DStr.Shape(Fd->Index(IFopArc)));
    TopTools_ListIteratorOfListOfShape It;
    // The face at end is returned without control of its unicity.
    for(It.Initialize(myEFMap(Arcpiv));It.More();It.Next()) {
      if(!Fad.IsSame(It.Value())){
	Fv = TopoDS::Face(It.Value());
	break;
      }
    }

    // does the face at end contain the Vertex ?
    Standard_Boolean isinface = Standard_False;
    for (ex.Init(Fv,TopAbs_VERTEX); ex.More(); ex.Next()){
      if (ex.Current().IsSame(Vtx)) {
	isinface = Standard_True;
	break;
      }
    }
    if (!isinface) {
      IFadArc = 3-IFadArc;
      IFopArc = 3-IFopArc;
      Arcpiv = Fd->Vertex(isfirst,IFadArc).Arc();
      Fad = TopoDS::Face(DStr.Shape(Fd->Index(IFadArc)));
      Fop = TopoDS::Face(DStr.Shape(Fd->Index(IFopArc)));
      //TopTools_ListIteratorOfListOfShape It;
    // The face at end is returned without control of its unicity.
     for(It.Initialize(myEFMap(Arcpiv));It.More();It.Next()) {
	if(!Fad.IsSame(It.Value())){
	  Fv = TopoDS::Face(It.Value());
	  break;
	}
      }
    }

    if(Fv.IsNull()) StdFail_NotDone::Raise
      ("OneCorner : face at end is not found");

    Fv.Orientation(TopAbs_FORWARD);
    Fad.Orientation(TopAbs_FORWARD);

    // In the same way the edge to be extended is returned.
    for(It.Initialize(myVEMap(Vtx));It.More() && Arcprol.IsNull();It.Next()){
      if(!Arcpiv.IsSame(It.Value())){
	for(ex.Init(Fv,TopAbs_EDGE); ex.More(); ex.Next()){
	  if(It.Value().IsSame(ex.Current())) {
	    Arcprol = TopoDS::Edge(It.Value());
	    OArcprolv = ex.Current().Orientation();
	    break;
	  }
	}
      }
    }

    //Fopbis is the face containing the trace of fillet CP.Arc() which of does not contain Vtx.
    //Normallly Fobis is either the same as Fop (cylinder), or Fobis is G1 with Fop.
    Fopbis.Orientation(TopAbs_FORWARD);

    //Fop calls the 4th face non-used for the vertex
    cherche_face(myVFMap(Vtx),Arcprol,Fad,Fv,Fv,Fopbis);
    Fop.Orientation(TopAbs_FORWARD);

    if(Arcprol.IsNull()) StdFail_NotDone::Raise
      ("OneCorner : edge to be extended is not found");
    for(ex.Init(Fopbis,TopAbs_EDGE); ex.More(); ex.Next()){
      if(Arcprol.IsSame(ex.Current())) {
	OArcprolop = ex.Current().Orientation();
	break;
      }
    }
    TopoDS_Face FFv;
    Standard_Real tol;
    Standard_Integer prol;
    BRep_Builder BRE;
    Handle(Geom_Surface ) Sface;
    Sface=BRep_Tool::Surface(Fv);
    ChFi3d_ExtendSurface(Sface,prol);
    tol=BRep_Tool::Tolerance(Fv);
    BRE.MakeFace(FFv,Sface,tol);
    if (prol) {
      Bs.Initialize(FFv,Standard_False);
      DStr.SetNewSurface(Fv,Sface);
    }
    else Bs.Initialize(Fv,Standard_False);
    Bad.Initialize(Fad);
    Bop.Initialize(Fop);
  }
  // it is necessary to modify the CommonPoint
  // in the space and its parameter in FaceInterference.
  // So both of them are returned in references
  // non const. Attention the modifications are done behind
  // CV1,CV2,Fi1,Fi2.
  ChFiDS_CommonPoint& CPopArc = Fd->ChangeVertex(isfirst,IFopArc);
  ChFiDS_FaceInterference& FiopArc = Fd->ChangeInterference(IFopArc);
  ChFiDS_CommonPoint& CPadArc = Fd->ChangeVertex(isfirst,IFadArc);
  ChFiDS_FaceInterference& FiadArc = Fd->ChangeInterference(IFadArc);
  // the parameter of the vertex is initialized with the value 
  // of its opposing vertex (point on arc).
  Standard_Real wop = Fd->ChangeInterference(IFadArc).Parameter(isfirst);
  Handle(Geom_Curve) c3df;
  Handle(GeomAdaptor_HSurface)
    HGs = new GeomAdaptor_HSurface(DStr.Surface(Fd->Surf()).Surface());
  gp_Pnt2d p2dbout;
  {

    // add here more or less restrictive criteria to
    // decide if the intersection with face is done at the
    // extended end or if there will be a cap on sharp end.
    c3df = DStr.Curve(FiopArc.LineIndex()).Curve();
    Standard_Real uf = FiopArc.FirstParameter();
    Standard_Real ul = FiopArc.LastParameter();
      Handle(GeomAdaptor_HCurve) Hc3df;
    if(c3df->IsPeriodic()){
      Hc3df = new GeomAdaptor_HCurve(c3df);
    }
    else{
      Hc3df = new GeomAdaptor_HCurve(c3df,uf,ul);
    }
    inters = Update(HBs,Hc3df,FiopArc,CPopArc,p2dbout,isfirst,wop);
//  Modified by Sergey KHROMOV - Fri Dec 21 18:08:27 2001 Begin
//  if(!inters && BRep_Tool::Continuity(Arcprol,Fv,Fop) != GeomAbs_C0){
    if(!inters && isTangentFaces(Arcprol,Fv,Fop)){
//  Modified by Sergey KHROMOV - Fri Dec 21 18:08:29 2001 End
      // Arcprol is an edge of tangency, ultimate adjustment by an extrema curve/curve is attempted.
      Standard_Real ff,ll;
      Handle(Geom2d_Curve) gpcprol = BRep_Tool::CurveOnSurface(Arcprol,Fv,ff,ll);
      Handle(Geom2dAdaptor_HCurve) pcprol = new Geom2dAdaptor_HCurve(gpcprol);
      Standard_Real partemp = BRep_Tool::Parameter(Vtx,Arcprol);
      inters = Update(HBs,pcprol,HGs,FiopArc,CPopArc,p2dbout,
		      isfirst,partemp,wop,10*tolesp);
    }
    Handle(BRepAdaptor_HCurve2d) pced = new BRepAdaptor_HCurve2d();
    pced->ChangeCurve2d().Initialize(CPadArc.Arc(),Fv);
    Update(HBs,pced,HGs,FiadArc,CPadArc,isfirst);
  }
#ifdef DEB
  ChFi3d_ResultChron(ch,t_same); // result perf condition if (same)
  ChFi3d_InitChron(ch); // init perf condition if (inters)
#endif

  TopoDS_Edge edgecouture;
  Standard_Boolean couture,intcouture=Standard_False;;
  Standard_Real tolreached = 0.0;
#ifndef DEB
  Standard_Real par1 = 0.,par2 = 0.;
  Standard_Integer indpt =0,Icurv1 =0,Icurv2 =0;
#else
  Standard_Real par1,par2;
  Standard_Integer indpt,Icurv1,Icurv2;
#endif
  Handle(Geom_TrimmedCurve) curv1,curv2;
  Handle(Geom2d_Curve) c2d1,c2d2;

  Standard_Integer Isurf=Fd->Surf();

  if (inters){
    HGs = ChFi3d_BoundSurf(DStr,Fd,1,2);
    const ChFiDS_FaceInterference& Fi1 = Fd->InterferenceOnS1();
    const ChFiDS_FaceInterference& Fi2 = Fd->InterferenceOnS2();
    TColStd_Array1OfReal Pardeb(1,4),Parfin(1,4);
    gp_Pnt2d pfil1,pfac1,pfil2,pfac2;
    Handle(Geom2d_Curve) Hc1,Hc2;
    if( IFopArc == 1) pfac1 = p2dbout;
    else {
      Hc1 = BRep_Tool::CurveOnSurface(CV1.Arc(),Fv,Ubid,Ubid);
      pfac1 = Hc1->Value(CV1.ParameterOnArc());
    }
    if(IFopArc == 2) pfac2 = p2dbout;
    else {
      Hc2 = BRep_Tool::CurveOnSurface(CV2.Arc(),Fv,Ubid,Ubid);
      pfac2 = Hc2->Value(CV2.ParameterOnArc());
    }
    if(Fi1.LineIndex() != 0){
      pfil1 = Fi1.PCurveOnSurf()->Value(Fi1.Parameter(isfirst));
    }
    else{
      pfil1 = Fi1.PCurveOnSurf()->Value(Fi1.Parameter(!isfirst));
    }
    if(Fi2.LineIndex() != 0){
      pfil2 = Fi2.PCurveOnSurf()->Value(Fi2.Parameter(isfirst));
    }
    else{
      pfil2 = Fi2.PCurveOnSurf()->Value(Fi2.Parameter(!isfirst));
    }
    ChFi3d_Recale(Bs,pfac1,pfac2,(IFadArc == 1));
    Pardeb(1)= pfil1.X();Pardeb(2) = pfil1.Y();
    Pardeb(3)= pfac1.X();Pardeb(4) = pfac1.Y();
    Parfin(1)= pfil2.X();Parfin(2) = pfil2.Y();
    Parfin(3)= pfac2.X();Parfin(4) = pfac2.Y();
    Standard_Real uu1,uu2,vv1,vv2;
    ChFi3d_Boite(pfac1,pfac2,uu1,uu2,vv1,vv2);
    ChFi3d_BoundFac(Bs,uu1,uu2,vv1,vv2);

    if (!ChFi3d_ComputeCurves(HGs,HBs,Pardeb,Parfin,Cc,
			      Ps,
			      Pc,tolesp,tol2d,tolreached))
    Standard_Failure::Raise("OneCorner : failed calculation intersection");

    Udeb = Cc->FirstParameter();
    Ufin = Cc->LastParameter();

    // check if the curve has an intersection with sewing edge

    ChFi3d_Couture(Fv,couture,edgecouture);

    if (couture  && !BRep_Tool::Degenerated(edgecouture)) {

      //Standard_Real Ubid,Vbid;
      Handle (Geom_Curve) C=BRep_Tool::Curve(edgecouture,Ubid,Vbid);
      Handle(Geom_TrimmedCurve) Ctrim=new Geom_TrimmedCurve (C,Ubid,Vbid);
      GeomAdaptor_Curve cur1(Ctrim->BasisCurve());
      GeomAdaptor_Curve cur2(Cc);
      Extrema_ExtCC extCC (cur1,cur2);
      if (extCC.IsDone()&&extCC.NbExt()!=0)
	{
	  Standard_Integer imin=0;
	  Standard_Real dist2min = RealLast();
	  for (Standard_Integer i = 1; i <= extCC.NbExt(); i++)
	    if (extCC.SquareDistance(i) < dist2min)
	      {
		dist2min = extCC.SquareDistance(i);
		imin = i;
	      }
	  if (dist2min <= Precision::Confusion() * Precision::Confusion())
	    {
	      Extrema_POnCurv ponc1,ponc2;
	      extCC.Points( imin, ponc1, ponc2 );
	      par1 = ponc1.Parameter();
	      par2 = ponc2.Parameter();
	      Standard_Real Tol = 1.e-4;
	      if (Abs(par2-Udeb) > Tol && Abs(Ufin-par2) > Tol)
		{
		  gp_Pnt P1=ponc1.Value();
		  TopOpeBRepDS_Point tpoint( P1, Tol );
		  indpt = DStr.AddPoint(tpoint);
		  intcouture = Standard_True;
		  curv1 = new Geom_TrimmedCurve(Cc,Udeb,par2);
		  curv2 = new Geom_TrimmedCurve(Cc,par2,Ufin);
		  TopOpeBRepDS_Curve tcurv1(curv1,tolreached);
		  TopOpeBRepDS_Curve tcurv2(curv2,tolreached);
		  Icurv1=DStr.AddCurve(tcurv1);
		  Icurv2=DStr.AddCurve(tcurv2);
		}
	    }
	}
    }
  }

  else{
    Standard_NotImplemented::Raise("OneCorner : cap not written");
  }
  Standard_Integer IShape = DStr.AddShape(Fv);
#ifndef DEB
  TopAbs_Orientation Et = TopAbs_FORWARD;
#else
  TopAbs_Orientation Et;
#endif
  if(IFadArc == 1){
    TopExp_Explorer Exp;
    for (Exp.Init(Fv.Oriented(TopAbs_FORWARD),
		  TopAbs_EDGE);Exp.More();Exp.Next()) {
      if (Exp.Current().IsSame(CV1.Arc())) {
	Et = TopAbs::Reverse(TopAbs::Compose
			     (Exp.Current().Orientation(),
			      CV1.TransitionOnArc()));
	break;
      }
    }
  }
  else{
    TopExp_Explorer Exp;
    for (Exp.Init(Fv.Oriented(TopAbs_FORWARD),
		  TopAbs_EDGE);Exp.More();Exp.Next()) {
      if (Exp.Current().IsSame(CV2.Arc())) {
	Et = TopAbs::Compose(Exp.Current().Orientation(),
			     CV2.TransitionOnArc());
	break;
      }
    }

//


  }

#ifdef DEB
  ChFi3d_ResultChron(ch ,t_inter); //result perf condition if (inter)
  ChFi3d_InitChron(ch); // init perf condition  if ( inters)
#endif

  stripe->SetIndexPoint(ChFi3d_IndexPointInDS(CV1,DStr),isfirst,1);
  stripe->SetIndexPoint(ChFi3d_IndexPointInDS(CV2,DStr),isfirst,2);

  if (!intcouture) {
// there is no intersection with edge of sewing
// curve Cc is stored in the stripe
// the storage in the DS is done by FILDS.

    TopOpeBRepDS_Curve Tc(Cc,tolreached);
    ICurve = DStr.AddCurve(Tc);
    Handle(TopOpeBRepDS_SurfaceCurveInterference)
      Interfc = ChFi3d_FilCurveInDS(ICurve,IShape,Pc,Et);
    DStr.ChangeShapeInterferences(IShape).Append(Interfc);
    stripe->ChangePCurve(isfirst)=Ps;
    stripe->SetCurve(ICurve,isfirst);
    stripe->SetParameters(isfirst,Udeb,Ufin);
   }
  else {
// curves curv1 and curv2 are stored in the DS
// these curves are not reconstructed by FILDS as
// stripe->InDS(isfirst) is placed;

    // interferences of curv1 and curv2 on Fv
    ComputeCurve2d(curv1,Fv,c2d1);
    Handle(TopOpeBRepDS_SurfaceCurveInterference) InterFv;
    InterFv = ChFi3d_FilCurveInDS(Icurv1,IShape,c2d1,Et);
    DStr.ChangeShapeInterferences(IShape).Append(InterFv);
    ComputeCurve2d(curv2,Fv,c2d2);
    InterFv = ChFi3d_FilCurveInDS(Icurv2,IShape,c2d2,Et);
    DStr.ChangeShapeInterferences(IShape).Append(InterFv);
     // interferences of curv1 and curv2 on Isurf
    if (Fd->Orientation()== Fv.Orientation()) Et=TopAbs::Reverse(Et);
    c2d1=new Geom2d_TrimmedCurve(Ps,Udeb,par2);
    InterFv = ChFi3d_FilCurveInDS(Icurv1,Isurf,c2d1,Et);
    DStr.ChangeSurfaceInterferences(Isurf).Append(InterFv);
    c2d2=new Geom2d_TrimmedCurve(Ps,par2,Ufin);
       InterFv = ChFi3d_FilCurveInDS(Icurv2,Isurf,c2d2,Et);
    DStr.ChangeSurfaceInterferences(Isurf).Append(InterFv);

      // limitation of the sewing edge
    Standard_Integer Iarc=DStr.AddShape(edgecouture);
    Handle(TopOpeBRepDS_CurvePointInterference) Interfedge;
    TopAbs_Orientation ori;
    TopoDS_Vertex Vdeb,Vfin;
    Vdeb=TopExp::FirstVertex(edgecouture);
    Vfin=TopExp::LastVertex(edgecouture);
    Standard_Real pard,parf;
    pard=BRep_Tool::Parameter(Vdeb,edgecouture);
    parf=BRep_Tool::Parameter(Vfin,edgecouture);
    if (Abs(par1-pard)<Abs(parf-par1)) ori=TopAbs_FORWARD;
    else ori=TopAbs_REVERSED;
    Interfedge = ChFi3d_FilPointInDS(ori,Iarc,indpt,par1);
    DStr.ChangeShapeInterferences(Iarc).Append(Interfedge);

    // creation of CurveInterferences from Icurv1 and Icurv2
    stripe->InDS(isfirst);
    Standard_Integer ind1= stripe->IndexPoint(isfirst,1);
    Standard_Integer ind2= stripe->IndexPoint(isfirst,2);
    Handle(TopOpeBRepDS_CurvePointInterference)
      interfprol = ChFi3d_FilPointInDS(TopAbs_FORWARD,Icurv1,ind1,Udeb);
    DStr.ChangeCurveInterferences(Icurv1).Append(interfprol);
    interfprol = ChFi3d_FilPointInDS(TopAbs_REVERSED,Icurv1,indpt,par2);
    DStr.ChangeCurveInterferences(Icurv1).Append(interfprol);
    interfprol = ChFi3d_FilPointInDS(TopAbs_FORWARD,Icurv2,indpt,par2);
    DStr.ChangeCurveInterferences(Icurv2).Append(interfprol);
    interfprol = ChFi3d_FilPointInDS(TopAbs_REVERSED,Icurv2,ind2,Ufin);
    DStr.ChangeCurveInterferences(Icurv2).Append(interfprol);

  }

  ChFi3d_EnlargeBox(HBs,Pc,Udeb,Ufin,box1,box2);

  if( inters){
//

    // The small end of curve missing for the extension
    // of the face at end and the limitation of the opposing face is added.

    // Above all the points cut the points with the edge of the spine.
    Standard_Integer IArcspine = DStr.AddShape(Arcspine);
    Standard_Integer IVtx = DStr.AddShape(Vtx);
    TopAbs_Orientation OVtx2 = TopAbs_FORWARD;
#ifndef DEB
    TopAbs_Orientation OVtx = TopAbs_FORWARD;
#else
    TopAbs_Orientation OVtx;
#endif
    for(ex.Init(Arcspine.Oriented(TopAbs_FORWARD),TopAbs_VERTEX);
	ex.More(); ex.Next()){
      if(Vtx.IsSame(ex.Current())) {
	OVtx = ex.Current().Orientation();
	break;
      }
    }
    OVtx = TopAbs::Reverse(OVtx);
    Standard_Real parVtx = BRep_Tool::Parameter(Vtx,Arcspine);
    Handle(TopOpeBRepDS_CurvePointInterference)
      interfv = ChFi3d_FilVertexInDS(OVtx,IArcspine,IVtx,parVtx);
    DStr.ChangeShapeInterferences(IArcspine).Append(interfv);


    //Modif of lvt to find the suite of Arcprol in the other face
    {
      TopTools_ListIteratorOfListOfShape It;
      for (It.Initialize(myVEMap(Vtx)); It.More(); It.Next()){
	if (!(Arcprol.IsSame(It.Value()) ||
	      Arcspine.IsSame(It.Value()) ||
	      Arcpiv.IsSame(It.Value()))) {
	  Arcprolbis = TopoDS::Edge(It.Value());
	  break;
	}
      }
    }
    //end of modif

    //Now the missing curves are constructed.
    for(ex.Init(Arcprolbis.Oriented(TopAbs_FORWARD),TopAbs_VERTEX);
	ex.More(); ex.Next()){
      if(Vtx.IsSame(ex.Current())) {
	OVtx2 = ex.Current().Orientation();
	break;
      }
    }
    for(ex.Init(Arcprol.Oriented(TopAbs_FORWARD),TopAbs_VERTEX);
	ex.More(); ex.Next()){
      if(Vtx.IsSame(ex.Current())) {
	OVtx = ex.Current().Orientation();
	break;
      }
    }
// it is checked if Fop has a sewing edge

//     TopoDS_Edge edgecouture;
//     Standard_Boolean couture;
    ChFi3d_Couture(Fop,couture,edgecouture);
    Handle(Geom2d_Curve) Hc;
//    parVtx = BRep_Tool::Parameter(Vtx,Arcprol);
    const ChFiDS_FaceInterference& Fiop = Fd->Interference(IFopArc);
    gp_Pnt2d pop1, pop2, pv1, pv2;
    //deb modif
    parVtx = BRep_Tool::Parameter(Vtx,Arcprolbis);
//  Modified by skv - Thu Aug 21 11:55:58 2008 OCC20222 Begin
//    if(Fop.IsSame(Fopbis)) OArcprolbis = OArcprolop;
//    else OArcprolbis = Arcprolbis.Orientation();
    if(Fop.IsSame(Fopbis)) {
      OArcprolbis = OArcprolop;
    } else {
      for(ex.Init(Fop,TopAbs_EDGE); ex.More(); ex.Next()){
	if(Arcprolbis.IsSame(ex.Current())) {
	  OArcprolbis = ex.Current().Orientation();
	  break;
	}
      }
    }
//  Modified by skv - Thu Aug 21 11:55:58 2008 OCC20222 End
    //fin modif
    Hc = BRep_Tool::CurveOnSurface(Arcprolbis,Fop,Ubid,Ubid);
    pop1 = Hc->Value(parVtx);
    pop2 = Fiop.PCurveOnFace()->Value(Fiop.Parameter(isfirst));
    Hc = BRep_Tool::CurveOnSurface(Arcprol,Fv,Ubid,Ubid);
    //modif
    parVtx = BRep_Tool::Parameter(Vtx,Arcprol);
    //fin modif
    pv1 = Hc->Value(parVtx);
    pv2 = p2dbout;
    ChFi3d_Recale(Bs,pv1,pv2,1);
    TColStd_Array1OfReal Pardeb(1,4),Parfin(1,4);
    Pardeb(1) = pop1.X(); Pardeb(2) = pop1.Y();
    Pardeb(3) = pv1.X();  Pardeb(4) = pv1.Y();
    Parfin(1) = pop2.X(); Parfin(2) = pop2.Y();
    Parfin(3) = pv2.X();  Parfin(4) = pv2.Y();
    Standard_Real uu1,uu2,vv1,vv2;
    ChFi3d_Boite(pv1,pv2,uu1,uu2,vv1,vv2);
    ChFi3d_BoundFac(Bs,uu1,uu2,vv1,vv2);
    ChFi3d_Boite(pop1,pop2,uu1,uu2,vv1,vv2);
    ChFi3d_BoundFac(Bop,uu1,uu2,vv1,vv2);

    Handle(Geom_Curve) zob3d;
    Handle(Geom2d_Curve) zob2dop, zob2dv;
//    Standard_Real tolreached;
    if (!ChFi3d_ComputeCurves(HBop,HBs,Pardeb,Parfin,zob3d,zob2dop,
			      zob2dv,tolesp,tol2d,tolreached))
      Standard_Failure::Raise("OneCorner : echec calcul intersection");

    Udeb = zob3d->FirstParameter();
    Ufin = zob3d->LastParameter();
    TopOpeBRepDS_Curve Zob(zob3d,tolreached);
    Standard_Integer IZob = DStr.AddCurve(Zob);

    // it is not determined if the curve has an intersection with the sewing edge


    {
      Et = TopAbs::Reverse(TopAbs::Compose(OVtx,OArcprolv));
      Standard_Integer Iop = DStr.AddShape(Fop);
      Handle(TopOpeBRepDS_SurfaceCurveInterference)
	InterFv = ChFi3d_FilCurveInDS(IZob,IShape,zob2dv,Et);
      DStr.ChangeShapeInterferences(IShape).Append(InterFv);
      //OVtx = TopAbs::Reverse(OVtx);
//  Modified by skv - Thu Aug 21 11:55:58 2008 OCC20222 Begin
//      Et = TopAbs::Reverse(TopAbs::Compose(OVtx,OArcprolbis));
      Et = TopAbs::Reverse(TopAbs::Compose(OVtx2,OArcprolbis));
//  Modified by skv - Thu Aug 21 11:55:58 2008 OCC20222 End
      //OVtx = TopAbs::Reverse(OVtx);
//      Et = TopAbs::Reverse(Et);
      Handle(TopOpeBRepDS_SurfaceCurveInterference)
	Interfop = ChFi3d_FilCurveInDS(IZob,Iop,zob2dop,Et);
      DStr.ChangeShapeInterferences(Iop).Append(Interfop);
      Handle(TopOpeBRepDS_CurvePointInterference)
	interfprol = ChFi3d_FilVertexInDS(TopAbs_FORWARD,IZob,IVtx,Udeb);
      DStr.ChangeCurveInterferences(IZob).Append(interfprol);
      Standard_Integer icc = stripe->IndexPoint(isfirst,IFopArc);
      interfprol = ChFi3d_FilPointInDS(TopAbs_REVERSED,IZob,icc,Ufin);
      DStr.ChangeCurveInterferences(IZob).Append(interfprol);

    }
  }
  ChFi3d_EnlargeBox(DStr,stripe,Fd,box1,box2,isfirst);
  if(CV1.IsOnArc()){
    ChFi3d_EnlargeBox(CV1.Arc(),myEFMap(CV1.Arc()),CV1.ParameterOnArc(),box1);
  }
  if(CV2.IsOnArc()){
    ChFi3d_EnlargeBox(CV2.Arc(),myEFMap(CV2.Arc()),CV2.ParameterOnArc(),box2);
  }
  if  (!CV1.IsVertex())
    ChFi3d_SetPointTolerance(DStr,box1,stripe->IndexPoint(isfirst,1));
  if (!CV2.IsVertex())
    ChFi3d_SetPointTolerance(DStr,box2,stripe->IndexPoint(isfirst,2));

#ifdef DEB
   ChFi3d_ResultChron(ch, t_sameinter);//result perf condition if (same &&inter)
#endif
}