X-Git-Url: http://git.salome-platform.org/gitweb/?p=modules%2Fsmesh.git;a=blobdiff_plain;f=src%2FSMESHUtils%2FSMESH_MeshAlgos.cxx;h=9bc76d69d4da63c1da3ed8857a3c0a7b9a2688cd;hp=9f0c88e20e9c849f9e1efe4dc7c1c24ea94853f7;hb=ff53fa3701555ca921fd568e921709528e26c5dc;hpb=dce88c3f8b2fd680f0ca56edc0c0518a0d58892c

diff --git a/src/SMESHUtils/SMESH_MeshAlgos.cxx b/src/SMESHUtils/SMESH_MeshAlgos.cxx
index 9f0c88e20..9bc76d69d 100644
--- a/src/SMESHUtils/SMESH_MeshAlgos.cxx
+++ b/src/SMESHUtils/SMESH_MeshAlgos.cxx
@@ -2252,6 +2252,56 @@ std::vector< const SMDS_MeshNode*> SMESH_MeshAlgos::GetCommonNodes(const SMDS_Me
   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