0025656: Specification of semantic of Closed flag of an edge

1. Using of the "Closed" flag was unified:
  a) this flag is applicable for TopoDS_Wire and TopoDS_Shell only, because these entities may hedge an area in 2D space or a volume in 3D space correspondingly;
  b) other types of TopoDS shapes are passing over this flag;
  c) changing of this flag should be controlled by high-level algorithms (not BRep_Builder).
2. Implemented verification of the closedness of edges. An edge is closed if and only if its first and last vertices are the same.
3. Test cases were changed according to new behavior.

src/BRepFill/BRepFill.cxx

@@ -304,7 +304,6 @@ TopoDS_Face BRepFill::Face(const TopoDS_Edge& Edge1,
   TopoDS_Edge Edge3, Edge4;
 
   Iso = Surf->UIso(f1);
-//  Tol = Max(BT.Tolerance(V1f), BT.Tolerance(V2f));
   Tol = Max(BRep_Tool::Tolerance(V1f), BRep_Tool::Tolerance(V2f));
   if (Iso->Value(f2).Distance(Iso->Value(l2)) > Tol) {
     B.MakeEdge(Edge3,Iso,Precision::Confusion());
@@ -324,7 +323,6 @@ TopoDS_Face BRepFill::Face(const TopoDS_Edge& Edge1,
   }
   else {
     Iso = Surf->UIso(l1);
-//    Tol = Max(BT.Tolerance(V1l), BT.Tolerance(V2l));
     Tol = Max(BRep_Tool::Tolerance(V1l), BRep_Tool::Tolerance(V2l));
     if (Iso->Value(l2).Distance(Iso->Value(f2)) > Tol) {
       B.MakeEdge(Edge4,Iso,Precision::Confusion());
@@ -436,7 +434,8 @@ TopoDS_Shell BRepFill::Shell(const TopoDS_Wire& Wire1,
     Edge1 = TopoDS::Edge(ex1.Current());
     Edge2 = TopoDS::Edge(ex2.Current());
 
-    Standard_Boolean Periodic = Edge1.Closed() && Edge2.Closed();
+    Standard_Boolean Periodic =
+      BRep_Tool::IsClosed(Edge1) && BRep_Tool::IsClosed(Edge2);
     
     ex1.Next();
     ex2.Next();

src/BRepFill/BRepFill_Evolved.cxx

@@ -3218,7 +3218,7 @@ void CutEdge (const TopoDS_Edge& E,
   CT2d = new Geom2d_TrimmedCurve(C2d,f,l);
 
   if (CT2d->BasisCurve()->IsKind(STANDARD_TYPE(Geom2d_Circle)) &&
-      E.Closed()) {
+      BRep_Tool::IsClosed(E)) {
     //---------------------------
     // Cut closed circle.
     //---------------------------

src/BRepFill/BRepFill_Filling.cxx

@@ -681,7 +681,7 @@ void BRepFill_Filling::Build()
     Handle(Geom2d_Curve) aCurveOnPlate = CurvesOnPlate->Value(i);
 
     TopoDS_Edge NewEdge = TopoDS::Edge(anEdge.EmptyCopied());
-    NewEdge.Closed(anEdge.Closed());
+
     TopoDS_Vertex V1, V2;
     TopExp::Vertices(anEdge, V1, V2, Standard_True); //with orientation
     BB.UpdateVertex(V1, dmax);

src/BRepFill/BRepFill_Generator.cxx

@@ -620,8 +620,8 @@ void BRepFill_Generator::Perform()
 	Edge2 = TopoDS::Edge(ex2.Current());
       }
 
-      Standard_Boolean Periodic
-	= (Edge1.Closed() || degen1) && (Edge2.Closed() || degen2);
+      Standard_Boolean Periodic = (BRep_Tool::IsClosed(Edge1) || degen1) &&
+                                  (BRep_Tool::IsClosed(Edge2) || degen2);
       // ATTENTION : a non-punctual wire should not 
       //             contain a punctual edge
       if (!wPoint1) ex1.Next();
@@ -648,13 +648,7 @@ void BRepFill_Generator::Perform()
 	  Vf_toMap = V1f;
 	  Vl_toMap = V1l;
 	}
-      
-      if(Periodic) {
-	Standard_Boolean E1IsReallyClosed = BRepTools::Compare(V1f,V1l);
-	Standard_Boolean E2IsReallyClosed = BRepTools::Compare(V2f,V2l);
-	Periodic 
-	  = (E1IsReallyClosed || degen1) && (E2IsReallyClosed || degen2);
-      }
+
       // processing of KPart
       Standard_Integer IType = DetectKPart(Edge1,Edge2);
       if (IType==0) {

src/BRepFill/BRepFill_NSections.cxx

@@ -573,7 +573,7 @@ void BRepFill_NSections::Init(const TColStd_SequenceOfReal & P,
 	    Last = aux;
 	    C =  CBis;
 	  } 
-	  if ((ii>1) || (!E.Closed()) ) { // Cut C
+	  if ((ii>1) || (!BRep_Tool::IsClosed(E)) ) { // Cut C
 	    Handle(Geom_TrimmedCurve) TC = 
 	      new (Geom_TrimmedCurve) (C,First, Last);
 	    C  = TC;

src/BRepFill/BRepFill_OffsetWire.cxx

@@ -251,9 +251,7 @@ static Standard_Boolean KPartCircle
     C = Ct->BasisCurve();
   }
 
-  TopoDS_Vertex V1,V2;
-  TopExp::Vertices(E,V1,V2);
-  if ((C->IsKind(STANDARD_TYPE(Geom_Circle)) && V1.IsSame(V2)) || //closed circle
+  if ((C->IsKind(STANDARD_TYPE(Geom_Circle)) && BRep_Tool::IsClosed(E)) || //closed circle
       IsOpenResult)
   {
     Standard_Real anOffset = myOffset;

src/BRepFill/BRepFill_Pipe.cxx

@@ -556,18 +556,18 @@ TopoDS_Shape BRepFill_Pipe::MakeShape(const TopoDS_Shape& S,
       B.MakeShell(TopoDS::Shell(result));
       B.MakeWire(W);
       B.Add(W, S);
-      W.Closed(S.Closed());
+      W.Closed(BRep_Tool::IsClosed(S));
       TheS = W;
       if (!FirstShape.IsNull()) {
 	B.MakeWire(W);
 	B.Add(W, FirstShape);
-	W.Closed(FirstShape.Closed());
+	W.Closed(BRep_Tool::IsClosed(FirstShape));
 	TheFirst = W;
       }
       if (!LastShape.IsNull()) {
 	B.MakeWire(W);
 	B.Add(W, LastShape);
-	W.Closed(LastShape.Closed());
+	W.Closed(BRep_Tool::IsClosed(LastShape));
 	TheLast = W;
       }
       result.Closed (BRep_Tool::IsClosed (result));

src/BRepFill/BRepFill_Section.cxx

@@ -46,7 +46,6 @@ BRepFill_Section::BRepFill_Section(const TopoDS_Shape& Profile,
       BB.Add( DegEdge, aVertex.Oriented(TopAbs_FORWARD) );
       BB.Add( DegEdge, aVertex.Oriented(TopAbs_REVERSED) );
       BB.Degenerated( DegEdge, Standard_True );
-      DegEdge.Closed( Standard_True );
       
       BB.MakeWire( wire );
       BB.Add( wire, DegEdge );

src/BRepFill/BRepFill_ShapeLaw.cxx

@@ -149,23 +149,12 @@ void BRepFill_ShapeLaw::Init(const Standard_Boolean Build)
 	    C = CBis;
 	  }
 
-	  Standard_Boolean IsReallyClosed = E.Closed();
-	  //IFV - some checking when closed flag is wrong
-	  if(IsReallyClosed) {
-	    TopoDS_Vertex V1, V2;
-	    TopExp::Vertices(E, V1, V2);
-	    if(V1.IsNull() || V2.IsNull()) {
-	      IsReallyClosed = Standard_False;
-	    }
-	    else {
-	      IsReallyClosed = V1.IsSame(V2);
-	    }
-	  }
-          if (IsReallyClosed &&
+          Standard_Boolean IsClosed = BRep_Tool::IsClosed(E);
+          if (IsClosed &&
               Abs(C->FirstParameter() - First) > Precision::PConfusion())
-            IsReallyClosed = Standard_False; //trimmed curve differs
+            IsClosed = Standard_False; //trimmed curve differs
 
-	  if ((ii>1) || !IsReallyClosed ) { // Trim C
+	  if ((ii>1) || !IsClosed ) { // Trim C
 	    Handle(Geom_TrimmedCurve) TC = new Geom_TrimmedCurve(C,First, Last);
 	    C = TC;
 	  }