From 29b9536d0187687b4251e1139e554ac62ea29446 Mon Sep 17 00:00:00 2001
From: Anthony Geay <anthony.geay@edf.fr>
Date: Thu, 14 Dec 2017 10:19:13 +0100
Subject: [PATCH] In progress

---
 src/MEDCoupling/MEDCouplingUMesh.cxx     | 44 ++++++++++++++++++++++++
 src/MEDCoupling/MEDCouplingUMesh.hxx     |  1 +
 src/MEDCoupling_Swig/MEDCouplingCommon.i | 10 ++++++
 3 files changed, 55 insertions(+)

diff --git a/src/MEDCoupling/MEDCouplingUMesh.cxx b/src/MEDCoupling/MEDCouplingUMesh.cxx
index 87c0118f0..5d5e1562b 100644
--- a/src/MEDCoupling/MEDCouplingUMesh.cxx
+++ b/src/MEDCoupling/MEDCouplingUMesh.cxx
@@ -922,6 +922,50 @@ void MEDCouplingUMesh::computeNeighborsOfNodes(DataArrayInt *&neighbors, DataArr
   neighborsIdx=descIndx.retn();
 }
 
+/*!
+ * Computes enlarged neighbors for each nodes in \a this. The behavior of this method is close to MEDCouplingUMesh::computeNeighborsOfNodes except that the neighborhood of each node is wider here.
+ * A node j is considered to be in the neighborhood of i if and only if there is a cell in \a this containing in its nodal connectivity both i and j.
+ * This method is useful to find ghost cells of a part of a mesh with a code based on fields on nodes.
+ * 
+ * \sa MEDCouplingUMesh::computeNeighborsOfNodes
+ */
+void MEDCouplingUMesh::computeEnlargedNeighborsOfNodes(MCAuto<DataArrayInt> &neighbors, MCAuto<DataArrayInt>& neighborsIdx) const
+{
+  checkFullyDefined();
+  int nbOfNodes(getNumberOfNodes());
+  const int *conn(_nodal_connec->begin()),*connIndex(_nodal_connec_index->begin());
+  int nbOfCells(getNumberOfCells());
+  std::vector< std::set<int> > st0(nbOfNodes);
+  for(int eltId=0;eltId<nbOfCells;eltId++)
+    {
+      const int *strtNdlConnOfCurCell(conn+connIndex[eltId]+1),*endNdlConnOfCurCell(conn+connIndex[eltId+1]);
+      std::set<int> s(strtNdlConnOfCurCell,endNdlConnOfCurCell); s.erase(-1); //for polyhedrons
+      for(std::set<int>::const_iterator iter2=s.begin();iter2!=s.end();iter2++)
+        st0[*iter2].insert(s.begin(),s.end());
+    }
+  neighborsIdx=DataArrayInt::New(); neighborsIdx->alloc(nbOfNodes+1,1); neighborsIdx->setIJ(0,0,0);
+  {
+    int *neighIdx(neighborsIdx->getPointer());
+    for(std::vector< std::set<int> >::const_iterator it=st0.begin();it!=st0.end();it++,neighIdx++)
+      {
+        if ((*it).empty())
+          neighIdx[1]=neighIdx[0];
+        else
+          neighIdx[1]=neighIdx[0]+(*it).size()-1;
+      }
+  }
+  neighbors=DataArrayInt::New(); neighbors->alloc(neighborsIdx->back(),1);
+  {
+    const int *neighIdx(neighborsIdx->begin());
+    int *neigh(neighbors->getPointer()),nodeId(0);
+    for(std::vector< std::set<int> >::const_iterator it=st0.begin();it!=st0.end();it++,neighIdx++,nodeId++)
+      {
+        std::set<int> s(*it); s.erase(nodeId);
+        std::copy(s.begin(),s.end(),neigh+*neighIdx);
+      }
+  }
+}
+
 /*!
  * Converts specified cells to either polygons (if \a this is a 2D mesh) or
  * polyhedrons (if \a this is a 3D mesh). The cells to convert are specified by an
diff --git a/src/MEDCoupling/MEDCouplingUMesh.hxx b/src/MEDCoupling/MEDCouplingUMesh.hxx
index efab092eb..082e3a833 100644
--- a/src/MEDCoupling/MEDCouplingUMesh.hxx
+++ b/src/MEDCoupling/MEDCouplingUMesh.hxx
@@ -129,6 +129,7 @@ namespace MEDCoupling
     MEDCOUPLING_EXPORT static void ComputeNeighborsOfCellsAdv(const DataArrayInt *desc, const DataArrayInt *descI, const DataArrayInt *revDesc, const DataArrayInt *revDescI,
                                                               DataArrayInt *&neighbors, DataArrayInt *&neighborsIdx);
     MEDCOUPLING_EXPORT void computeNeighborsOfNodes(DataArrayInt *&neighbors, DataArrayInt *&neighborsIdx) const;
+    MEDCOUPLING_EXPORT void computeEnlargedNeighborsOfNodes(MCAuto<DataArrayInt> &neighbors, MCAuto<DataArrayInt>& neighborsIdx) const;
     MEDCOUPLING_EXPORT MEDCouplingUMesh *mergeMyselfWithOnSameCoords(const MEDCouplingPointSet *other) const;
     MEDCOUPLING_EXPORT MEDCouplingUMesh *buildPartOfMySelf(const int *begin, const int *end, bool keepCoords=true) const;
     MEDCOUPLING_EXPORT MEDCouplingUMesh *buildPartOfMySelfSlice(int start, int end, int step, bool keepCoords=true) const;
diff --git a/src/MEDCoupling_Swig/MEDCouplingCommon.i b/src/MEDCoupling_Swig/MEDCouplingCommon.i
index a1a557ecc..f5057c88a 100644
--- a/src/MEDCoupling_Swig/MEDCouplingCommon.i
+++ b/src/MEDCoupling_Swig/MEDCouplingCommon.i
@@ -2732,6 +2732,16 @@ namespace MEDCoupling
         PyTuple_SetItem(ret,1,SWIG_NewPointerObj(SWIG_as_voidptr(neighborsIdx),SWIGTYPE_p_MEDCoupling__DataArrayInt, SWIG_POINTER_OWN | 0 ));
         return ret;
       }
+
+      PyObject *computeEnlargedNeighborsOfNodes() const throw(INTERP_KERNEL::Exception)
+      {
+        MCAuto<DataArrayInt> neighbors,neighborsIdx;
+        self->computeEnlargedNeighborsOfNodes(neighbors,neighborsIdx);
+        PyObject *ret=PyTuple_New(2);
+        PyTuple_SetItem(ret,0,SWIG_NewPointerObj(SWIG_as_voidptr(neighbors.retn()),SWIGTYPE_p_MEDCoupling__DataArrayInt, SWIG_POINTER_OWN | 0 ));
+        PyTuple_SetItem(ret,1,SWIG_NewPointerObj(SWIG_as_voidptr(neighborsIdx.retn()),SWIGTYPE_p_MEDCoupling__DataArrayInt, SWIG_POINTER_OWN | 0 ));
+        return ret;
+      }
       
       PyObject *computeCellNeighborhoodFromNodesOne(const DataArrayInt *nodeNeigh, const DataArrayInt *nodeNeighI) const throw(INTERP_KERNEL::Exception)
       {
-- 
2.39.2