-// Copyright (C) 2007-2012 CEA/DEN, EDF R&D
+// Copyright (C) 2007-2020 CEA/DEN, EDF R&D
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
-// version 2.1 of the License.
+// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
#include "BlockTopology.hxx"
-namespace ParaMEDMEM
+namespace MEDCoupling
{
class DEC;
class BlockTopology;
+
+ /*!
+ \anchor StructuredCoincidentDEC-det
+ \class StructuredCoincidentDEC
+
+ This class aims at \ref interpolation "remapping fields" that have identical
+ structured supports (=the same underlying mesh) but different parallel topologies
+ (=different sub-domains in the structured mesh). It can be used to couple
+ together multi-physics codes that operate on the same domain
+ with different partitioning. This can be useful for example if one of
+ the computation is much faster than the other. It can also be used
+ to couple together codes that share an interface that was generated
+ in the same manner (with identical global ids).
+ Also, this \ref para-dec "DEC" can be used for fields that have component topologies,
+ i.e., components that are scattered over several processors.
+
+ The remapping between the two supports is based on identity of global
+ ids, instead of geometrical considerations (as it is the case for
+ \ref InterpKernelDEC-det "InterpKernelDEC").
+ Therefore, beware that this \ref para-dec "DEC" can not be used
+ for coincident meshes if they do *not* have the exact same numbering.
+
+ With this %DEC no projection, and no interpolation of the field data is done, contrary
+ to what happens in \ref InterpKernelDEC-det "InterpKernelDEC". It is just
+ a matter of allocating the values from one side to the other, using directly the cell
+ identifiers.
+
+ As all the other DECs, its usage requires two phases :
+ - a setup phase during which the topologies are exchanged so that
+ the target side knows from which processors it should expect
+ the data.
+ - a send/recv phase during which the field data is actually transferred.
+
+ This example illustrates the sending of a field with
+ the \c StructuredCoincidentDEC :
+ \code
+ ...
+ StructuredCoincidentDEC dec(groupA, groupB);
+ dec.attachLocalField(field);
+ dec.synchronize();
+ if (groupA.containsMyRank())
+ dec.recvData();
+ else if (groupB.containsMyRank())
+ dec.sendData();
+ ...
+ \endcode
+
+ Creating a ParaFIELD to be attached to the %DEC is done in exactly the same way as for
+ the other DECs, if only the partitioning of the support mesh differs.
+ In the case where the
+ fields have also different *component* topologies, creating the ParaFIELD
+ requires some more effort. See the \ref para-over "parallelism" section for more details.
+ */
class StructuredCoincidentDEC : public DisjointDEC
{
public: