0030560: Modeling Algorithms - Improvement of the method BRepTools::DetectClosedness

1. Rewrite the method BRepTools::DetectClosedness.
2. Correct the method BRepOffset_Tool::EnLargeFace to process properly non-periodic but closed faces.

src/BRepOffset/BRepOffset_Tool.cxx

@@ -3103,6 +3103,7 @@ Standard_Boolean BRepOffset_Tool::EnLargeFace
   TopLoc_Location       L;
   Handle (Geom_Surface) S = BRep_Tool::Surface(F,L);
   Standard_Real         UU1,VV1,UU2,VV2;
+  Standard_Boolean      uperiodic = Standard_False, vperiodic = Standard_False;
   Standard_Boolean      isVV1degen = Standard_False, isVV2degen = Standard_False;
   Standard_Real         US1,VS1,US2,VS2;
   Standard_Real         UF1,VF1,UF2,VF2;
@@ -3146,6 +3147,7 @@ Standard_Boolean BRepOffset_Tool::EnLargeFace
   }
 
   if (S->IsUPeriodic()) {
+    uperiodic = Standard_True;
     Standard_Real    Period = S->UPeriod(); 
     Standard_Real    Delta  = Period - (UF2 - UF1);
     Standard_Real    alpha  = 0.1;
@@ -3155,6 +3157,7 @@ Standard_Boolean BRepOffset_Tool::EnLargeFace
     }
   }
   if (S->IsVPeriodic()) {
+    vperiodic = Standard_True;
     Standard_Real    Period = S->VPeriod(); 
     Standard_Real    Delta  = Period - (VF2 - VF1);
     Standard_Real    alpha  = 0.1;
@@ -3199,6 +3202,12 @@ Standard_Boolean BRepOffset_Tool::EnLargeFace
   //Detect closedness in U and V directions
   Standard_Boolean uclosed = Standard_False, vclosed = Standard_False;
   BRepTools::DetectClosedness(F, uclosed, vclosed);
+  if (uclosed && !uperiodic &&
+      (theLenBeforeUfirst != 0. || theLenAfterUlast != 0.))
+    uclosed = Standard_False;
+  if (vclosed && !vperiodic &&
+      (theLenBeforeVfirst != 0. && theLenAfterVlast != 0.))
+    vclosed = Standard_False;
   
   MakeFace(S,UU1,UU2,VV1,VV2,uclosed,vclosed,isVV1degen,isVV2degen,BF);
   BF.Location(L);

src/BRepTools/BRepTools.cxx

@@ -67,25 +67,6 @@
 #include <errno.h>
 
 
-//=======================================================================
-//function : IsPCurveUiso
-//purpose  : 
-//=======================================================================
-
-static Standard_Boolean IsPCurveUiso(const Handle(Geom2d_Curve)& thePCurve,
-                                     Standard_Real theFirstPar,
-                                     Standard_Real theLastPar)
-{
-  gp_Pnt2d FirstP2d = thePCurve->Value(theFirstPar);
-  gp_Pnt2d LastP2d  = thePCurve->Value(theLastPar);
-
-  Standard_Real DeltaU = Abs(FirstP2d.X() - LastP2d.X());
-  Standard_Real DeltaV = Abs(FirstP2d.Y() - LastP2d.Y());
-
-  return (DeltaU < DeltaV);
-}
-
-
 //=======================================================================
 //function : UVBounds
 //purpose  : 
@@ -977,28 +958,24 @@ void BRepTools::DetectClosedness(const TopoDS_Face& theFace,
 {
   theUclosed = theVclosed = Standard_False;
   
-  BRepAdaptor_Surface BAsurf(theFace, Standard_False);
-  Standard_Boolean IsSurfUclosed = BAsurf.IsUClosed();
-  Standard_Boolean IsSurfVclosed = BAsurf.IsVClosed();
-  if (!IsSurfUclosed && !IsSurfVclosed)
-    return;
-  
   TopExp_Explorer Explo(theFace, TopAbs_EDGE);
   for (; Explo.More(); Explo.Next())
   {
     const TopoDS_Edge& anEdge = TopoDS::Edge(Explo.Current());
-    if (BRepTools::IsReallyClosed(anEdge, theFace))
+    if (BRep_Tool::IsClosed(anEdge, theFace) &&
+        BRepTools::IsReallyClosed(anEdge, theFace))
     {
       Standard_Real fpar, lpar;
-      Handle(Geom2d_Curve) aPCurve = BRep_Tool::CurveOnSurface(anEdge, theFace, fpar, lpar);
+      Handle(Geom2d_Curve) PCurve1 = BRep_Tool::CurveOnSurface(anEdge, theFace, fpar, lpar);
-      Standard_Boolean IsUiso = IsPCurveUiso(aPCurve, fpar, lpar);
+      Handle(Geom2d_Curve) PCurve2 = BRep_Tool::CurveOnSurface(TopoDS::Edge(anEdge.Reversed()),
-      if (IsSurfUclosed && IsUiso)
+                                                               theFace, fpar, lpar);
+      gp_Pnt2d Point1 = PCurve1->Value(fpar);
+      gp_Pnt2d Point2 = PCurve2->Value(fpar);
+      Standard_Boolean IsUiso = (Abs(Point1.X() - Point2.X()) > Abs(Point1.Y() - Point2.Y()));
+      if (IsUiso)
         theUclosed = Standard_True;
-      if (IsSurfVclosed && !IsUiso)
+      else
         theVclosed = Standard_True;
-      
-      if (theUclosed && theVclosed)
-        break;
     }
   }
 }

tests/bugs/modalg_7/bug30560_1

@@ -0,0 +1,12 @@
+puts "==============================================================="
+puts "OCC30560: Improvement of the method BRepTools::DetectClosedness"
+puts "==============================================================="
+puts ""
+
+pload QAcommands
+
+restore [locate_data_file bug30560_face.brep] a
+
+OCC30391 result a 0. 0. 2. 2.
+
+checknbshapes result -vertex 2 -edge 3

tests/bugs/modalg_7/bug30560_2

@@ -0,0 +1,12 @@
+puts "==============================================================="
+puts "OCC30560: Improvement of the method BRepTools::DetectClosedness"
+puts "==============================================================="
+puts ""
+
+pload QAcommands
+
+restore [locate_data_file bug30560_face.brep] a
+
+OCC30391 result a 2. 2. 2. 2.
+
+checknbshapes result -vertex 4 -edge 4