diff --git a/src/BOPAlgo/BOPAlgo_BuilderFace.cdl b/src/BOPAlgo/BOPAlgo_BuilderFace.cdl
index ac99e8d03f..42e640ac46 100644
--- a/src/BOPAlgo/BOPAlgo_BuilderFace.cdl
+++ b/src/BOPAlgo/BOPAlgo_BuilderFace.cdl
@@ -26,7 +26,8 @@ class BuilderFace from BOPAlgo
 	 
 	---Purpose: The algorithm to build faces from set of edges  
 
-uses   
+uses    
+    Orientation from TopAbs,
     Face from TopoDS,
     BaseAllocator from BOPCol 
 --raises
@@ -76,9 +77,13 @@ is
      
     CheckData(me:out) 
 	is redefined protected;   
-
+     
+    Orientation(me) 
+    	returns Orientation from TopAbs; 
+ 
 fields  
     myFace : Face from TopoDS is protected;     
-     
+    myOrientation: Orientation from TopAbs is protected;   	      
+ 
 end BuilderFace; 
 
diff --git a/src/BOPAlgo/BOPAlgo_BuilderFace.cxx b/src/BOPAlgo/BOPAlgo_BuilderFace.cxx
index 5ad003ef6e..2b3e34307f 100644
--- a/src/BOPAlgo/BOPAlgo_BuilderFace.cxx
+++ b/src/BOPAlgo/BOPAlgo_BuilderFace.cxx
@@ -83,6 +83,7 @@ static
 :
   BOPAlgo_BuilderArea()
 {
+  myOrientation=TopAbs_EXTERNAL;
 }
 //=======================================================================
 //function : 
@@ -91,7 +92,8 @@ static
   BOPAlgo_BuilderFace::BOPAlgo_BuilderFace(const Handle(NCollection_BaseAllocator)& theAllocator)
 :
   BOPAlgo_BuilderArea(theAllocator)
-{
+{ 
+  myOrientation=TopAbs_EXTERNAL;
 }
 //=======================================================================
 //function : ~
@@ -106,7 +108,17 @@ static
 //=======================================================================
   void BOPAlgo_BuilderFace::SetFace(const TopoDS_Face& theFace)
 {
+  myOrientation=theFace.Orientation();
   myFace=theFace;
+  myFace.Orientation(TopAbs_FORWARD);
+}
+//=======================================================================
+//function : Orientation
+//purpose  : 
+//=======================================================================
+TopAbs_Orientation BOPAlgo_BuilderFace::Orientation()const
+{
+  return myOrientation;
 }
 //=======================================================================
 //function : Face
diff --git a/src/BOPAlgo/BOPAlgo_Builder_2.cxx b/src/BOPAlgo/BOPAlgo_Builder_2.cxx
index 54f2a9a601..528f54b853 100644
--- a/src/BOPAlgo/BOPAlgo_Builder_2.cxx
+++ b/src/BOPAlgo/BOPAlgo_Builder_2.cxx
@@ -54,12 +54,14 @@
 
 #include <BOPTools.hxx>
 #include <BOPTools_AlgoTools.hxx>
+#include <BOPTools_AlgoTools2D.hxx>
 #include <BOPTools_AlgoTools3D.hxx>
 #include <BOPAlgo_BuilderFace.hxx>
 #include <BOPTools_CoupleOfShape.hxx>
 #include <BOPTools_ListOfCoupleOfShape.hxx>
 #include <BOPTools_MapOfSet.hxx>
 #include <BOPTools_DataMapOfShapeSet.hxx>
+#include <BOPAlgo_Builder_2Cnt.hxx>
 
 static
   Standard_Boolean HasPaveBlocksOnIn(const BOPDS_FaceInfo& aFI1,
@@ -74,11 +76,12 @@ static
                      BOPCol_DataMapOfIntegerListOfShape& aMBlocks,
                      Handle(NCollection_IncAllocator)& aAllocator);
 
+
 //=======================================================================
 //function : FillImagesFaces
 //purpose  : 
 //=======================================================================
-  void BOPAlgo_Builder::FillImagesFaces()
+void BOPAlgo_Builder::FillImagesFaces()
 {
   myErrorStatus=0;
   //
@@ -90,10 +93,12 @@ static
 //function : BuildSplitFaces
 //purpose  : 
 //=======================================================================
-  void BOPAlgo_Builder::BuildSplitFaces()
+void BOPAlgo_Builder::BuildSplitFaces()
 {
   Standard_Boolean bHasFaceInfo, bIsClosed, bIsDegenerated, bToReverse;
   Standard_Integer i, j, aNbS, aNbPBIn, aNbPBOn, aNbPBSc, aNbAV, nSp;
+  Standard_Boolean bRunParallel;
+  Standard_Size aNbBF, k;
   TopoDS_Face aFF, aFSD;
   TopoDS_Edge aSp, aEE;
   TopAbs_Orientation anOriF, anOriE;
@@ -101,9 +106,10 @@ static
   BOPCol_ListIteratorOfListOfShape aIt;
   BOPCol_ListOfInteger aLIAV;
   BOPCol_MapOfShape aMFence;
-  Handle(NCollection_IncAllocator) aAllocator;
+  Handle(NCollection_BaseAllocator) aAllocator;
   BOPCol_ListOfShape aLFIm(myAllocator);
   BOPCol_MapIteratorOfMapOfShape aItMS;
+  BOPAlgo_VectorOfBuilderFace aVBF;
   //
   myErrorStatus=0;
   //
@@ -114,6 +120,7 @@ static
   BOPCol_MapOfShape aMDE(100, aAllocator);
   //
   aNbS=myDS->NbSourceShapes();
+  //
   for (i=0; i<aNbS; ++i) {
     const BOPDS_ShapeInfo& aSI=myDS->ShapeInfo(i);
     if (aSI.ShapeType()!=TopAbs_FACE) {
@@ -127,9 +134,6 @@ static
       continue;
     }
     //
-    // aLFIm will contain images of aF
-    aLFIm.Clear();
-    //
     const BOPDS_FaceInfo& aFI=myDS->FaceInfo(i);
     //
     const BOPDS_IndexedMapOfPaveBlock& aMPBIn=aFI.PaveBlocksIn();
@@ -247,17 +251,29 @@ static
       aLE.Append(aSp);
     }
     //
+    BOPTools_AlgoTools2D::BuildPCurveForEdgesOnPlane (aLE, aFF);
+    //
     // 3 Build split faces
-    BOPAlgo_BuilderFace aBF(aAllocator);
-    //
-    aBF.SetFace(aFF);
-    //aBF.SetContext(myContext);
-    //
-    // <-DEB ft
-    //
+    BOPAlgo_BuilderFace& aBF=aVBF.Append1();
+    aBF.SetFace(aF);
     aBF.SetShapes(aLE);
     //
-    aBF.Perform();
+  }// for (i=0; i<aNbS; ++i) {
+  //
+  aNbBF=aVBF.Extent();
+  //
+  //===================================================
+  bRunParallel=Standard_True;
+  BOPAlgo_BuilderFaceCnt::Perform(bRunParallel, aVBF);
+  //===================================================
+  //
+  for (k=0; k<aNbBF; ++k) {
+    aLFIm.Clear();
+    //
+    BOPAlgo_BuilderFace& aBF=aVBF(k);
+    TopoDS_Face aF=aBF.Face();
+    anOriF=aBF.Orientation();
+    aF.Orientation(anOriF);
     //
     const BOPCol_ListOfShape& aLFR=aBF.Areas();
     aIt.Initialize(aLFR);
@@ -271,7 +287,7 @@ static
     }
     //
     mySplits.Bind(aF, aLFIm); 
-  }// for (i=0; i<aNbS; ++i) {
+  }// for (k=0; k<aNbBF; ++k) {
   //
   aAllocator.Nullify();
   //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~scope t
@@ -280,7 +296,7 @@ static
 //function : FillSameDomainFaces
 //purpose  : 
 //=======================================================================
-  void BOPAlgo_Builder::FillSameDomainFaces()
+void BOPAlgo_Builder::FillSameDomainFaces()
 {
   Standard_Boolean bFlag;
   Standard_Integer i, aNbFFs, aNbCurves, aNbPoints, nF1, nF2, aNbS;
@@ -450,7 +466,7 @@ static
 // function: FillImagesFaces1
 // purpose: 
 //=======================================================================
-  void BOPAlgo_Builder::FillImagesFaces1()
+void BOPAlgo_Builder::FillImagesFaces1()
 {
   Standard_Integer i, aNbS, iSense;
   TopoDS_Face aFSD;
@@ -508,8 +524,8 @@ static
 // function: FillInternalVertices
 // purpose: 
 //=======================================================================
-  void BOPAlgo_Builder::FillInternalVertices(BOPCol_ListOfShape& aLFIm,
-                                             BOPCol_ListOfInteger& aLIAV)
+void BOPAlgo_Builder::FillInternalVertices(BOPCol_ListOfShape& aLFIm,
+					   BOPCol_ListOfInteger& aLIAV)
 {
   Standard_Integer nV, iFlag;
   Standard_Real aU1, aU2;
@@ -681,7 +697,6 @@ Standard_Boolean HasPaveBlocksOnIn(const BOPDS_FaceInfo& aFI1,
   }
   return bRet;
 }
-
 /*
 //DEBf
     {
diff --git a/src/BOPAlgo/BOPAlgo_Builder_2Cnt.hxx b/src/BOPAlgo/BOPAlgo_Builder_2Cnt.hxx
new file mode 100644
index 0000000000..626cef3408
--- /dev/null
+++ b/src/BOPAlgo/BOPAlgo_Builder_2Cnt.hxx
@@ -0,0 +1,133 @@
+// Created by: Peter KURNEV
+// Copyright (c) 1999-2013 OPEN CASCADE SAS
+//
+// The content of this file is subject to the Open CASCADE Technology Public
+// License Version 6.5 (the "License"). You may not use the content of this file
+// except in compliance with the License. Please obtain a copy of the License
+// at http://www.opencascade.org and read it completely before using this file.
+//
+// The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
+// main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
+//
+// The Original Code and all software distributed under the License is
+// distributed on an "AS IS" basis, without warranty of any kind, and the
+// Initial Developer hereby disclaims all such warranties, including without
+// limitation, any warranties of merchantability, fitness for a particular
+// purpose or non-infringement. Please see the License for the specific terms
+// and conditions governing the rights and limitations under the License.
+
+#ifndef BOPAlgo_Builder_2Cnt_HeaderFile
+#define BOPAlgo_Builder_2Cnt_HeaderFile
+
+/*
+#ifdef HAVE_TBB
+#undef HAVE_TBB
+#endif
+*/
+#include <BOPCol_NCVector.hxx>
+#include <BOPAlgo_BuilderFace.hxx>
+
+#ifdef HAVE_TBB
+#include <BOPCol_TBB.hxx>
+
+#define flexible_range blocked_range
+#define flexible_for   parallel_for
+#else 
+#define flexible_range serial_range
+#define flexible_for   serial_for
+#endif
+
+//=======================================================================
+//class : serial_range
+//purpose  : 
+//=======================================================================
+template <class Type> class serial_range {
+ public:
+  serial_range(const Type& aBegin,
+	       const Type& aEnd)
+    : myBegin(aBegin), myEnd(aEnd) {
+  }
+  //
+  ~serial_range() {
+  }
+  //
+  const Type& begin() const{
+    return myBegin;
+  }
+  //
+  const Type& end() const{
+    return myEnd;
+  };
+  //
+ protected:
+  Type myBegin;
+  Type myEnd;
+};
+//=======================================================================
+//function : serial_for
+//purpose  : 
+//=======================================================================
+template<typename Range, typename Body>
+static void serial_for( const Range& range, const Body& body ) {
+  body.operator()(range);
+};
+//
+//=======================================================================
+//class    : BOPAlgo_VectorOfBuilderFace
+//purpose  : 
+//=======================================================================
+typedef BOPCol_NCVector<BOPAlgo_BuilderFace> BOPAlgo_VectorOfBuilderFace;
+//
+//=======================================================================
+//class    : BOPAlgo_BuilderFaceFunctor
+//purpose  : 
+//=======================================================================
+class BOPAlgo_BuilderFaceFunctor {
+ protected:
+  BOPAlgo_VectorOfBuilderFace* myPVBF;
+  //
+ public:
+  //
+  BOPAlgo_BuilderFaceFunctor(BOPAlgo_VectorOfBuilderFace& aVBF) 
+    : myPVBF(&aVBF) {
+  }
+  //
+  void operator()( const flexible_range<Standard_Size>& aBR ) const{
+    Standard_Size i, iBeg, iEnd;
+    //
+    BOPAlgo_VectorOfBuilderFace& aVBF=*myPVBF;
+    //
+    iBeg=aBR.begin();
+    iEnd=aBR.end();
+    for(i=iBeg; i!=iEnd; ++i) {
+      BOPAlgo_BuilderFace& aBF=aVBF(i);
+      //
+      aBF.Perform();
+    }
+  }
+};
+//=======================================================================
+//class    : BOPAlgo_BuilderFaceCnt
+//purpose  : 
+//=======================================================================
+class BOPAlgo_BuilderFaceCnt {
+ public:
+  //-------------------------------
+  // Perform
+  Standard_EXPORT static void Perform(const Standard_Boolean bRunParallel,
+				      BOPAlgo_VectorOfBuilderFace& aVBF) {
+    //
+    BOPAlgo_BuilderFaceFunctor aBFF(aVBF);
+    Standard_Size aNbBF=aVBF.Extent();
+    //
+    if (bRunParallel) {
+      flexible_for(flexible_range<Standard_Size>(0,aNbBF), aBFF);
+    }
+    else {
+      aBFF.operator()(flexible_range<Standard_Size>(0,aNbBF));
+    }
+  }
+  //
+};
+
+#endif
diff --git a/src/BOPAlgo/BOPAlgo_WireSplitter_1.cxx b/src/BOPAlgo/BOPAlgo_WireSplitter_1.cxx
index 71b7af0636..fb9132c7c9 100644
--- a/src/BOPAlgo/BOPAlgo_WireSplitter_1.cxx
+++ b/src/BOPAlgo/BOPAlgo_WireSplitter_1.cxx
@@ -48,6 +48,7 @@
 #include <BOPCol_SequenceOfReal.hxx>
 #include <TopExp.hxx>
 #include <TopExp_Explorer.hxx>
+#include <BOPTools_AlgoTools2D.hxx>
 //
 
 static
@@ -111,9 +112,7 @@ static
   Standard_Real Tolerance2D (const TopoDS_Vertex& aV,
                              const GeomAdaptor_Surface& aGAS);
 
-static
-  void BuildPCurveForPlane (const BOPCol_ListOfShape myEdges,
-                            const TopoDS_Face& myFace);
+
 
 static
   Standard_Real UTolerance2D (const TopoDS_Vertex& aV,
@@ -154,7 +153,8 @@ static
   const BOPCol_ListOfShape& myEdges=aCB.Shapes();
   //
   // 1.Filling mySmartMap
-  BuildPCurveForPlane(myEdges, myFace);
+  BOPTools_AlgoTools2D::BuildPCurveForEdgesOnPlane(myEdges, myFace);
+  //
   aIt.Initialize(myEdges);
   for(; aIt.More(); aIt.Next()) {
     const TopoDS_Edge& aE=(*(TopoDS_Edge *)&aIt.Value());
@@ -817,42 +817,7 @@ Standard_Real Angle (const gp_Dir2d& aDir2D)
   //
   return aTol2D;
 }
-//=======================================================================
-// function: BuildPCurvesForPlane
-// purpose: 
-//=======================================================================
-  void BuildPCurveForPlane (const BOPCol_ListOfShape myEdges,
-                            const TopoDS_Face& myFace)
-{
-  TopLoc_Location aLoc;
-  Handle(Geom2d_Curve) aC2D;
-  Handle(Geom_Plane) aGP;
-  Handle(Geom_RectangularTrimmedSurface) aGRTS;
-  //
-  const Handle(Geom_Surface)& aS = BRep_Tool::Surface(myFace, aLoc);
-  aGRTS=Handle(Geom_RectangularTrimmedSurface)::DownCast(aS);
-  if(!aGRTS.IsNull()){
-    aGP=Handle(Geom_Plane)::DownCast(aGRTS->BasisSurface());
-    }    
-  else {
-    aGP=Handle(Geom_Plane)::DownCast(aS);
-  }
-  //
-  if (aGP.IsNull()) {
-    return;
-  }
-  //
-  Standard_Real aTolE;
-  BOPCol_ListIteratorOfListOfShape aIt;
-  BRep_Builder aBB;
-  //
-  aIt.Initialize(myEdges);
-  for(; aIt.More(); aIt.Next()) {
-    const TopoDS_Edge& aE=(*(TopoDS_Edge *)&aIt.Value());
-    BOPTools_AlgoTools2D::CurveOnSurface(aE, myFace, aC2D, aTolE);
-    aBB.UpdateEdge(aE, aC2D, myFace, aTolE);
-  }
-}
+
 //=======================================================================
 //function : UTolerance2D
 //purpose  : 
diff --git a/src/BOPAlgo/FILES b/src/BOPAlgo/FILES
index f2caa5c223..01a0706439 100644
--- a/src/BOPAlgo/FILES
+++ b/src/BOPAlgo/FILES
@@ -13,3 +13,5 @@ BOPAlgo_Builder_4.cxx
 BOPAlgo_BOP_1.cxx
 BOPAlgo_WireSplitter_1.cxx
 BOPAlgo_ListOfCheckResult.hxx
+
+BOPAlgo_Builder_2Cnt.hxx
diff --git a/src/BOPCol/BOPCol.cdl b/src/BOPCol/BOPCol.cdl
index 9937dace42..c898bb85dd 100644
--- a/src/BOPCol/BOPCol.cdl
+++ b/src/BOPCol/BOPCol.cdl
@@ -54,5 +54,6 @@ is
     imported DataMapOfIntegerListOfShape from BOPCol;
     imported IndexedDataMapOfIntegerListOfInteger from BOPCol;
     imported IndexedDataMapOfShapeInteger from BOPCol;  
+   
     
 end BOPCol;
diff --git a/src/BOPCol/BOPCol_NCVector.hxx b/src/BOPCol/BOPCol_NCVector.hxx
new file mode 100644
index 0000000000..a23c8c4563
--- /dev/null
+++ b/src/BOPCol/BOPCol_NCVector.hxx
@@ -0,0 +1,61 @@
+// Created by: Peter KURNEV
+// Copyright (c) 1999-2013 OPEN CASCADE SAS
+//
+// The content of this file is subject to the Open CASCADE Technology Public
+// License Version 6.5 (the "License"). You may not use the content of this file
+// except in compliance with the License. Please obtain a copy of the License
+// at http://www.opencascade.org and read it completely before using this file.
+//
+// The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
+// main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
+//
+// The Original Code and all software distributed under the License is
+// distributed on an "AS IS" basis, without warranty of any kind, and the
+// Initial Developer hereby disclaims all such warranties, including without
+// limitation, any warranties of merchantability, fitness for a particular
+// purpose or non-infringement. Please see the License for the specific terms
+// and conditions governing the rights and limitations under the License.
+
+
+#ifndef BOPCol_NCVector_HeaderFile
+#define BOPCol_NCVector_HeaderFile
+
+#include <Standard.hxx>
+#include <NCollection_Vector.hxx>
+#include <NCollection_BaseAllocator.hxx>
+
+//=======================================================================
+//class    : BOPCol_NCVector
+//purpose  : 
+//=======================================================================
+template <class Type> class BOPCol_NCVector 
+  :
+  public NCollection_Vector<Type>
+{
+ public:
+  BOPCol_NCVector(const Standard_Integer theIncrement=256,
+		  const Handle_NCollection_BaseAllocator& theAlloc = NULL) 
+    : NCollection_Vector<Type>(theIncrement, theAlloc) {
+  };
+  //
+  BOPCol_NCVector(const BOPCol_NCVector& theOther) 
+    : NCollection_Vector<Type>(theOther) {
+  };
+  //
+  Type& Append1 ()
+  {
+    Type& anAppended = 
+      *(Type* )expandV (NCollection_BaseCollection<Type>::myAllocator, 
+			NCollection_Vector<Type>::myLength);
+    return anAppended;
+  }
+  //
+  Standard_Integer Extent() const
+  {
+    return NCollection_Vector<Type>::myLength;
+  }
+ protected:
+  
+};
+
+#endif
diff --git a/src/BOPCol/BOPCol_TBB.hxx b/src/BOPCol/BOPCol_TBB.hxx
new file mode 100644
index 0000000000..fbde3bc85e
--- /dev/null
+++ b/src/BOPCol/BOPCol_TBB.hxx
@@ -0,0 +1,31 @@
+// Created by: Peter KURNEV
+// Copyright (c) 1999-2013 OPEN CASCADE SAS
+//
+// The content of this file is subject to the Open CASCADE Technology Public
+// License Version 6.5 (the "License"). You may not use the content of this file
+// except in compliance with the License. Please obtain a copy of the License
+// at http://www.opencascade.org and read it completely before using this file.
+//
+// The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
+// main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
+//
+// The Original Code and all software distributed under the License is
+// distributed on an "AS IS" basis, without warranty of any kind, and the
+// Initial Developer hereby disclaims all such warranties, including without
+// limitation, any warranties of merchantability, fitness for a particular
+// purpose or non-infringement. Please see the License for the specific terms
+// and conditions governing the rights and limitations under the License.
+
+#ifndef _BOPDS_Col_HeaderFile
+#define _BOPDS_Col_HeaderFile
+
+#ifdef HAVE_TBB
+
+
+#include <tbb/tbb.h>
+using namespace tbb;
+
+
+#endif
+
+#endif
diff --git a/src/BOPCol/FILES b/src/BOPCol/FILES
index 3543673a7b..e1d8d8ba58 100644
--- a/src/BOPCol/FILES
+++ b/src/BOPCol/FILES
@@ -28,4 +28,7 @@ BOPCol_DataMapOfIntegerListOfShape.hxx
 BOPCol_SequenceOfReal.hxx
 BOPCol_DataMapOfIntegerShape.hxx
 BOPCol_IndexedDataMapOfIntegerListOfInteger.hxx
-BOPCol_IndexedDataMapOfShapeInteger.hxx
\ No newline at end of file
+BOPCol_IndexedDataMapOfShapeInteger.hxx
+
+BOPCol_TBB.hxx
+BOPCol_NCVector.hxx
diff --git a/src/BOPTools/BOPTools_AlgoTools2D.cdl b/src/BOPTools/BOPTools_AlgoTools2D.cdl
index 7be6e33787..94674bc608 100644
--- a/src/BOPTools/BOPTools_AlgoTools2D.cdl
+++ b/src/BOPTools/BOPTools_AlgoTools2D.cdl
@@ -32,8 +32,9 @@ uses
      
     Curve from Geom2d,
     Curve from Geom, 
-    ProjectedCurve from ProjLib
-
+    ProjectedCurve from ProjLib,
+    ListOfShape from BOPCol 
+    
 is   
 
     BuildPCurveForEdgeOnFace  (myclass; 
@@ -144,6 +145,10 @@ is
           ---
     BuildPCurveForEdgeOnPlane(myclass; 
               theE : Edge from TopoDS; 
+              theF : Face from TopoDS); 
+	      
+    BuildPCurveForEdgesOnPlane(myclass; 
+              theLE : ListOfShape from BOPCol; 
               theF : Face from TopoDS);
  
     Make2D  (myclass;  
diff --git a/src/BOPTools/BOPTools_AlgoTools2D.cxx b/src/BOPTools/BOPTools_AlgoTools2D.cxx
index 9bfda5dd68..e52bd3cbef 100755
--- a/src/BOPTools/BOPTools_AlgoTools2D.cxx
+++ b/src/BOPTools/BOPTools_AlgoTools2D.cxx
@@ -400,8 +400,8 @@ static
 //function : BuildPCurveForEdgeOnPlane
 //purpose  : 
 //=======================================================================
-  void BOPTools_AlgoTools2D::BuildPCurveForEdgeOnPlane (const TopoDS_Edge& aE,
-                                                    const TopoDS_Face& aF)
+void BOPTools_AlgoTools2D::BuildPCurveForEdgeOnPlane (const TopoDS_Edge& aE,
+						      const TopoDS_Face& aF)
 { 
   Standard_Real aTolE;
   TopLoc_Location aLoc;
@@ -428,14 +428,57 @@ static
   //
   return;
 }
+//=======================================================================
+// function: BuildPCurveForEdgesOnPlane
+// purpose: 
+//=======================================================================
+void BOPTools_AlgoTools2D::BuildPCurveForEdgesOnPlane 
+  (const BOPCol_ListOfShape& aEdges,
+   const TopoDS_Face& aFace)
+{
+  
+  TopLoc_Location aLoc;
+  Handle(Geom2d_Curve) aC2D;
+  Handle(Geom_Plane) aGP;
+  Handle(Geom_RectangularTrimmedSurface) aGRTS;
+  //
+  const Handle(Geom_Surface)& aS = BRep_Tool::Surface(aFace, aLoc);
+  aGRTS=Handle(Geom_RectangularTrimmedSurface)::DownCast(aS);
+  if(!aGRTS.IsNull()){
+    aGP=Handle(Geom_Plane)::DownCast(aGRTS->BasisSurface());
+    }    
+  else {
+    aGP=Handle(Geom_Plane)::DownCast(aS);
+  }
+  //
+  if (aGP.IsNull()) {
+    return;
+  }
+  //
+  Standard_Boolean bHasOld;
+  Standard_Real aTolE, aT1, aT2;
+  BOPCol_ListIteratorOfListOfShape aIt;
+  BRep_Builder aBB;
+  //
+  aIt.Initialize(aEdges);
+  for(; aIt.More(); aIt.Next()) {
+    const TopoDS_Edge& aE=(*(TopoDS_Edge *)&aIt.Value());
+    bHasOld=BOPTools_AlgoTools2D::HasCurveOnSurface
+      (aE, aFace, aC2D, aT1, aT2, aTolE);
+    if (!bHasOld) {
+      BOPTools_AlgoTools2D::CurveOnSurface(aE, aFace, aC2D, aTolE);
+      aBB.UpdateEdge(aE, aC2D, aFace, aTolE);
+    }
+  }
+}
 
 //=======================================================================
 //function : Make2D
 //purpose  : 
 //=======================================================================
-  void BOPTools_AlgoTools2D::Make2D (const TopoDS_Edge& aE,
-                                 const TopoDS_Face& aF,
-                                 Handle(Geom2d_Curve)& aC2D,
+void BOPTools_AlgoTools2D::Make2D (const TopoDS_Edge& aE,
+				   const TopoDS_Face& aF,
+				   Handle(Geom2d_Curve)& aC2D,
                                  Standard_Real& aFirst,
                                  Standard_Real& aLast,
                                  Standard_Real& aToler)