ENH: polyBoundaryMesh additional faces() and faceOwner() slice methods

- return a subList view of the mesh faces, owners

applications/test/foamMeshToTet-vtk/writeVTKtetMesh.C

@@ -52,9 +52,9 @@ void writeVTKtetMesh(const fileName& output, const polyMesh& mesh_)
     {
         nTets += 2 * faces[facei].nTriangles();
     }
-    for (label facei = mesh_.nInternalFaces(); facei < mesh_.nFaces(); ++facei)
+    for (const face& f : mesh_.boundaryMesh().faces())
     {
-        nTets += faces[facei].nTriangles();
+        nTets += f.nTriangles();
     }
     const label nPoints = (mesh_.nPoints() + mesh_.nCells());
 

src/OpenFOAM/meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.C

@@ -300,6 +300,34 @@ void Foam::polyBoundaryMesh::calcGeometry()
 }
 
 
+const Foam::faceList::subList Foam::polyBoundaryMesh::faces() const
+{
+    return faceList::subList
+    (
+        mesh_.faces(),
+        mesh_.nBoundaryFaces(),
+        mesh_.nInternalFaces()
+    );
+}
+
+
+const Foam::labelList::subList Foam::polyBoundaryMesh::faceOwner() const
+{
+    return labelList::subList
+    (
+        mesh_.faceOwner(),
+        mesh_.nBoundaryFaces(),
+        mesh_.nInternalFaces()
+    );
+}
+
+// Potentially useful to simplify logic elsewhere?
+// const Foam::labelList::subList Foam::polyBoundaryMesh::faceNeighbour() const
+// {
+//     return labelList::subList();
+// }
+
+
 Foam::UPtrList<const Foam::labelUList>
 Foam::polyBoundaryMesh::faceCells() const
 {

src/OpenFOAM/meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.H

@@ -171,6 +171,12 @@ public:
             return mesh_;
         }
 
+        //- Return mesh faces for the entire boundary
+        const faceList::subList faces() const;
+
+        //- Return face owner for the entire boundary
+        const labelList::subList faceOwner() const;
+
         //- Return a list of faceCells for each patch
         UPtrList<const labelUList> faceCells() const;