return common;
}
+//================================================================================
+/*!
+ * \brief Return true if a node is on a boundary of 2D mesh.
+ * Optionally returns two neighboring boundary nodes (or more in non-manifold mesh)
+ */
+//================================================================================
+
+bool SMESH_MeshAlgos::IsOn2DBoundary( const SMDS_MeshNode* theNode,
+ std::vector< const SMDS_MeshNode*> * theNeibors )
+{
+ typedef NCollection_DataMap< SMESH_TLink, int, SMESH_TLink > TLinkCountMap;
+ TLinkCountMap linkCountMap( 10 );
+
+ int nbFreeLinks = 0;
+ for ( SMDS_ElemIteratorPtr fIt = theNode->GetInverseElementIterator(SMDSAbs_Face); fIt->more(); )
+ {
+ const SMDS_MeshElement* face = fIt->next();
+ const int nbCorners = face->NbCornerNodes();
+
+ int iN = face->GetNodeIndex( theNode );
+ int iPrev = ( iN - 1 + nbCorners ) % nbCorners;
+ int iNext = ( iN + 1 ) % nbCorners;
+
+ for ( int i : { iPrev, iNext } )
+ {
+ SMESH_TLink link( theNode, face->GetNode( i ));
+ int* count = linkCountMap.ChangeSeek( link );
+ if ( count ) ++( *count );
+ else linkCountMap.Bind( link, 1 );
+
+ if ( !count ) ++nbFreeLinks;
+ else --nbFreeLinks;
+ }
+ }
+
+ if ( theNeibors )
+ {
+ theNeibors->clear();
+ theNeibors->reserve( nbFreeLinks );
+ for ( TLinkCountMap::Iterator linkIt( linkCountMap ); linkIt.More(); linkIt.Next() )
+ if ( linkIt.Value() == 1 )
+ {
+ theNeibors->push_back( linkIt.Key().node1() );
+ if ( theNeibors->back() == theNode )
+ theNeibors->back() = linkIt.Key().node2();
+ }
+ }
+ return nbFreeLinks > 0;
+}
+
//================================================================================
/*!
* \brief Return true if node1 encounters first in the face and node2, after
