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Merge from V6_main 11/02/2013
[modules/smesh.git] / src / SMESH / SMESH_Gen.cxx
index 1febbb03a9c115e3def980976eb6cb06f5c914e6..a9ef17d1eb215f0aa5ebb2679111f65eef81a9bb 100644 (file)
-//  SMESH SMESH : implementaion of SMESH idl descriptions
+// Copyright (C) 2007-2012  CEA/DEN, EDF R&D, OPEN CASCADE
 //
-//  Copyright (C) 2003  OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
-//  CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS
+// Copyright (C) 2003-2007  OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
+// CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS
 //
-//  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.
+// 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.
 //
-//  This library is distributed in the hope that it will be useful,
-//  but WITHOUT ANY WARRANTY; without even the implied warranty of
-//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-//  Lesser General Public License for more details.
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
 //
-//  You should have received a copy of the GNU Lesser General Public
-//  License along with this library; if not, write to the Free Software
-//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 //
 // See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
 //
-//
-//
+
+//  SMESH SMESH : implementaion of SMESH idl descriptions
 //  File   : SMESH_Gen.cxx
 //  Author : Paul RASCLE, EDF
 //  Module : SMESH
-//  $Header$
+//
+
+//#define CHRONODEF
 
 #include "SMESH_Gen.hxx"
-#include "SMESH_subMesh.hxx"
-#include "SMESH_HypoFilter.hxx"
+
+#include "SMDS_Mesh.hxx"
 #include "SMDS_MeshElement.hxx"
 #include "SMDS_MeshNode.hxx"
+#include "SMESHDS_Document.hxx"
+#include "SMESH_HypoFilter.hxx"
+#include "SMESH_MesherHelper.hxx"
+#include "SMESH_subMesh.hxx"
 
 #include "utilities.h"
 #include "OpUtil.hxx"
 #include "Utils_ExceptHandlers.hxx"
 
-#include <gp_Pnt.hxx>
-#include <BRep_Tool.hxx>
-#include <TopTools_ListOfShape.hxx>
-#include <TopTools_ListIteratorOfListOfShape.hxx>
+#include <TopoDS_Iterator.hxx>
+#include <LDOMParser.hxx>
+
+#include "memoire.h"
+
+#ifdef WNT
+  #include <windows.h>
+#endif\r
 
 using namespace std;
 
+//#include <vtkDebugLeaks.h>
+
+
 //=============================================================================
 /*!
- *  default constructor:
+ *  Constructor
  */
 //=============================================================================
 
 SMESH_Gen::SMESH_Gen()
 {
-       MESSAGE("SMESH_Gen::SMESH_Gen");
-       _localId = 0;
-       _hypId = 0;
+        MESSAGE("SMESH_Gen::SMESH_Gen");
+        _localId = 0;
+        _hypId = 0;
+        _segmentation = _nbSegments = 10;
+        SMDS_Mesh::_meshList.clear();
+        MESSAGE(SMDS_Mesh::_meshList.size());
+        //_counters = new counters(100);
+#ifdef WITH_SMESH_CANCEL_COMPUTE
+        _compute_canceled = false;
+        _sm_current = NULL;
+#endif
+        //vtkDebugLeaks::SetExitError(0);
 }
 
 //=============================================================================
 /*!
- *
+ * Destructor
  */
 //=============================================================================
 
 SMESH_Gen::~SMESH_Gen()
 {
-       MESSAGE("SMESH_Gen::~SMESH_Gen");
+  MESSAGE("SMESH_Gen::~SMESH_Gen");
+  std::map < int, StudyContextStruct * >::iterator i_sc = _mapStudyContext.begin();
+  for ( ; i_sc != _mapStudyContext.end(); ++i_sc )
+  {
+    delete i_sc->second->myDocument;
+    delete i_sc->second;
+  }  
 }
 
 //=============================================================================
 /*!
- *
- */
-//=============================================================================
-
-/*SMESH_Hypothesis *SMESH_Gen::CreateHypothesis(const char *anHyp, int studyId)
-       throw(SALOME_Exception)
-{
-
-       MESSAGE("CreateHypothesis("<<anHyp<<","<<studyId<<")");
-       // Get studyContext, create it if it does'nt exist, with a SMESHDS_Document
-
-       StudyContextStruct *myStudyContext = GetStudyContext(studyId);
-
-       // create a new hypothesis object, store its ref. in studyContext
-
-       SMESH_Hypothesis *myHypothesis = _hypothesisFactory.Create(anHyp, studyId);
-       int hypId = myHypothesis->GetID();
-       myStudyContext->mapHypothesis[hypId] = myHypothesis;
-       SCRUTE(studyId);
-       SCRUTE(hypId);
-
-       // store hypothesis in SMESHDS document
-
-       myStudyContext->myDocument->AddHypothesis(myHypothesis);
-       return myHypothesis;
-}*/
-
-//=============================================================================
-/*!
- *
+ * Creates a mesh in a study.
+ * if (theIsEmbeddedMode) { mesh modification commands are not logged }
  */
 //=============================================================================
 
@@ -113,129 +113,441 @@ SMESH_Mesh* SMESH_Gen::CreateMesh(int theStudyId, bool theIsEmbeddedMode)
 
   // create a new SMESH_mesh object
   SMESH_Mesh *aMesh = new SMESH_Mesh(_localId++,
-                                    theStudyId,
-                                    this,
-                                    theIsEmbeddedMode,
-                                    aStudyContext->myDocument);
-  aStudyContext->mapMesh[_localId] = aMesh;
+                                     theStudyId,
+                                     this,
+                                     theIsEmbeddedMode,
+                                     aStudyContext->myDocument);
+  aStudyContext->mapMesh[_localId-1] = aMesh;
 
   return aMesh;
 }
 
 //=============================================================================
 /*!
- *
+ * Compute a mesh
  */
 //=============================================================================
 
-bool SMESH_Gen::Compute(SMESH_Mesh & aMesh, const TopoDS_Shape & aShape)
+bool SMESH_Gen::Compute(SMESH_Mesh &          aMesh,
+                        const TopoDS_Shape &  aShape,
+                        const bool            anUpward,
+                        const ::MeshDimension aDim,
+                        TSetOfInt*            aShapesId)
 {
   MESSAGE("SMESH_Gen::Compute");
-  //   bool isDone = false;
-  /*
-     Algo : s'appuie ou non sur une geometrie
-     Si geometrie:
-     Vertex : rien à faire (range le point)
-     Edge, Wire, collection d'edge et wire : 1D
-     Face, Shell, collection de Face et Shells : 2D
-     Solid, Collection de Solid : 3D
-     */
-  // *** corriger commentaires
-  // check hypothesis associated to the mesh :
-  // - only one algo : type compatible with the type of the shape
-  // - hypothesis = compatible with algo
-  //    - check if hypothesis are applicable to this algo
-  //    - check contradictions within hypothesis
-  //    (test if enough hypothesis is done further)
+  MEMOSTAT;
 
   bool ret = true;
 
-//   if ( !CheckAlgoState( aMesh, aShape ))
-//   {
-//     INFOS( "ABORT MESHING: some algos or hypothesis are missing");
-//     return false;
-//   }
-
   SMESH_subMesh *sm = aMesh.GetSubMesh(aShape);
 
-  if ( sm->GetComputeState() == SMESH_subMesh::COMPUTE_OK )
-    return true; // already computed
-
-  // -----------------------------------------------------------------
-  // apply algos that do not require descretized boundaries, starting
-  // from the most complex shapes
-  // -----------------------------------------------------------------
+  const bool includeSelf = true;
+  const bool complexShapeFirst = true;
+  const int  globalAlgoDim = 100;
 
-  // map containing all subshapes in the order: vertices, edges, faces...
-  const map<int, SMESH_subMesh*>& smMap = sm->DependsOn();
-  map<int, SMESH_subMesh*>::const_reverse_iterator revItSub = smMap.rbegin();
+  SMESH_subMeshIteratorPtr smIt;
 
-  SMESH_subMesh* smToCompute = sm;
-  while ( smToCompute )
+  if ( anUpward ) // is called from below code here
   {
-    const TopoDS_Shape& aSubShape = smToCompute->GetSubShape();
-    if ( GetShapeDim( aSubShape ) < 1 ) break;
-
-    SMESH_Algo* algo = GetAlgo( aMesh, aSubShape );
-    if (algo && !algo->NeedDescretBoundary()) {
-      if (smToCompute->GetComputeState() == SMESH_subMesh::READY_TO_COMPUTE) {
-        ret = smToCompute->ComputeStateEngine( SMESH_subMesh::COMPUTE );
-      } else if (smToCompute->GetComputeState() == SMESH_subMesh::FAILED_TO_COMPUTE) {
-        // JFA for PAL6524
+    // -----------------------------------------------
+    // mesh all the sub-shapes starting from vertices
+    // -----------------------------------------------
+    smIt = sm->getDependsOnIterator(includeSelf, !complexShapeFirst);
+    while ( smIt->more() )
+    {
+      SMESH_subMesh* smToCompute = smIt->next();
+
+      // do not mesh vertices of a pseudo shape
+      const TopAbs_ShapeEnum aShType = smToCompute->GetSubShape().ShapeType();
+      if ( !aMesh.HasShapeToMesh() && aShType == TopAbs_VERTEX )
+        continue;
+
+      // check for preview dimension limitations
+      if ( aShapesId && GetShapeDim( aShType ) > (int)aDim )
+      {
+        // clear compute state not to show previous compute errors
+        //  if preview invoked less dimension less than previous
+        smToCompute->ComputeStateEngine( SMESH_subMesh::CHECK_COMPUTE_STATE );
+        continue;
+      }
+
+      if (smToCompute->GetComputeState() == SMESH_subMesh::READY_TO_COMPUTE)
+      {
+#ifdef WITH_SMESH_CANCEL_COMPUTE
+        if (_compute_canceled)
+          return false;
+        _sm_current = smToCompute;
+#endif
+        smToCompute->ComputeStateEngine( SMESH_subMesh::COMPUTE );
+#ifdef WITH_SMESH_CANCEL_COMPUTE
+        _sm_current = NULL;
+#endif
+      }
+
+      // we check all the submeshes here and detect if any of them failed to compute
+      if (smToCompute->GetComputeState() == SMESH_subMesh::FAILED_TO_COMPUTE)
         ret = false;
-      } else {
+      else if ( aShapesId )
+        aShapesId->insert( smToCompute->GetId() );
+    }
+    //aMesh.GetMeshDS()->Modified();
+    return ret;
+  }
+  else
+  {
+    // -----------------------------------------------------------------
+    // apply algos that DO NOT require Discreteized boundaries and DO NOT
+    // support submeshes, starting from the most complex shapes
+    // and collect submeshes with algos that DO support submeshes
+    // -----------------------------------------------------------------
+    list< SMESH_subMesh* > smWithAlgoSupportingSubmeshes;
+
+    // map to sort sm with same dim algos according to dim of
+    // the shape the algo assigned to (issue 0021217)
+    multimap< int, SMESH_subMesh* > shDim2sm;
+    multimap< int, SMESH_subMesh* >::reverse_iterator shDim2smIt;
+    TopoDS_Shape algoShape;
+    int prevShapeDim = -1;
+
+    smIt = sm->getDependsOnIterator(includeSelf, complexShapeFirst);
+    while ( smIt->more() )
+    {
+      SMESH_subMesh* smToCompute = smIt->next();
+      if ( smToCompute->GetComputeState() != SMESH_subMesh::READY_TO_COMPUTE )
+        continue;
+
+      const TopoDS_Shape& aSubShape = smToCompute->GetSubShape();
+      int aShapeDim = GetShapeDim( aSubShape );
+      if ( aShapeDim < 1 ) break;
+      
+      // check for preview dimension limitations
+      if ( aShapesId && aShapeDim > (int)aDim )
+        continue;
+
+      SMESH_Algo* algo = GetAlgo( aMesh, aSubShape, &algoShape );
+      if ( algo && !algo->NeedDiscreteBoundary() )
+      {
+        if ( algo->SupportSubmeshes() )
+        {
+          // reload sub-meshes from shDim2sm into smWithAlgoSupportingSubmeshes
+          // so that more local algos to go first
+          if ( prevShapeDim != aShapeDim )
+          {
+            prevShapeDim = aShapeDim;
+            for ( shDim2smIt = shDim2sm.rbegin(); shDim2smIt != shDim2sm.rend(); ++shDim2smIt )
+              if ( shDim2smIt->first == globalAlgoDim )
+                smWithAlgoSupportingSubmeshes.push_back( shDim2smIt->second );
+              else
+                smWithAlgoSupportingSubmeshes.push_front( shDim2smIt->second );
+            shDim2sm.clear();
+          }
+          // add smToCompute to shDim2sm map
+          if ( algoShape.IsSame( aMesh.GetShapeToMesh() ))
+          {
+            aShapeDim = globalAlgoDim; // to compute last
+          }
+          else
+          {
+            aShapeDim = GetShapeDim( algoShape );
+            if ( algoShape.ShapeType() == TopAbs_COMPOUND )
+            {
+              TopoDS_Iterator it( algoShape );
+              aShapeDim += GetShapeDim( it.Value() );
+            }
+          }
+          shDim2sm.insert( make_pair( aShapeDim, smToCompute ));
+        }
+        else
+        {
+#ifdef WITH_SMESH_CANCEL_COMPUTE
+          if (_compute_canceled)
+            return false;
+          _sm_current = smToCompute;
+#endif
+          smToCompute->ComputeStateEngine( SMESH_subMesh::COMPUTE );
+#ifdef WITH_SMESH_CANCEL_COMPUTE
+          _sm_current = NULL;
+#endif
+          if ( aShapesId )
+            aShapesId->insert( smToCompute->GetId() );
+        }
       }
     }
-    if (!ret)
-      return false;
+    // reload sub-meshes from shDim2sm into smWithAlgoSupportingSubmeshes
+    for ( shDim2smIt = shDim2sm.rbegin(); shDim2smIt != shDim2sm.rend(); ++shDim2smIt )
+      if ( shDim2smIt->first == globalAlgoDim )
+        smWithAlgoSupportingSubmeshes.push_back( shDim2smIt->second );
+      else
+        smWithAlgoSupportingSubmeshes.push_front( shDim2smIt->second );
+
+    // ------------------------------------------------------------
+    // sort list of submeshes according to mesh order
+    // ------------------------------------------------------------
+    aMesh.SortByMeshOrder( smWithAlgoSupportingSubmeshes );
+
+    // ------------------------------------------------------------
+    // compute submeshes under shapes with algos that DO NOT require
+    // Discreteized boundaries and DO support submeshes
+    // ------------------------------------------------------------
+    list< SMESH_subMesh* >::iterator subIt, subEnd;
+    subIt  = smWithAlgoSupportingSubmeshes.begin();
+    subEnd = smWithAlgoSupportingSubmeshes.end();
+    // start from lower shapes
+    for ( ; subIt != subEnd; ++subIt )
+    {
+      sm = *subIt;
+
+      // get a shape the algo is assigned to
+      if ( !GetAlgo( aMesh, sm->GetSubShape(), & algoShape ))
+        continue; // strange...
 
-    // next subMesh
-    if (revItSub != smMap.rend())
+      // look for more local algos
+      smIt = sm->getDependsOnIterator(!includeSelf, !complexShapeFirst);
+      while ( smIt->more() )
+      {
+        SMESH_subMesh* smToCompute = smIt->next();
+
+        const TopoDS_Shape& aSubShape = smToCompute->GetSubShape();
+        const int aShapeDim = GetShapeDim( aSubShape );
+        //if ( aSubShape.ShapeType() == TopAbs_VERTEX ) continue;
+        if ( aShapeDim < 1 ) continue;
+
+        // check for preview dimension limitations
+        if ( aShapesId && GetShapeDim( aSubShape.ShapeType() ) > (int)aDim )
+          continue;
+        
+        SMESH_HypoFilter filter( SMESH_HypoFilter::IsAlgo() );
+        filter
+          .And( SMESH_HypoFilter::IsApplicableTo( aSubShape ))
+          .And( SMESH_HypoFilter::IsMoreLocalThan( algoShape, aMesh ));
+
+        if ( SMESH_Algo* subAlgo = (SMESH_Algo*) aMesh.GetHypothesis( aSubShape, filter, true )) {
+          if ( ! subAlgo->NeedDiscreteBoundary() ) continue;
+          SMESH_Hypothesis::Hypothesis_Status status;
+          if ( subAlgo->CheckHypothesis( aMesh, aSubShape, status ))
+            // mesh a lower smToCompute starting from vertices
+            Compute( aMesh, aSubShape, /*anUpward=*/true, aDim, aShapesId );
+        }
+      }
+    }
+    // ----------------------------------------------------------
+    // apply the algos that do not require Discreteized boundaries
+    // ----------------------------------------------------------
+    for ( subIt = smWithAlgoSupportingSubmeshes.begin(); subIt != subEnd; ++subIt )
     {
-      smToCompute = (*revItSub).second;
-      revItSub++;
+      sm = *subIt;
+      if ( sm->GetComputeState() == SMESH_subMesh::READY_TO_COMPUTE)
+      {
+        const TopAbs_ShapeEnum aShType = sm->GetSubShape().ShapeType();
+        // check for preview dimension limitations
+        if ( aShapesId && GetShapeDim( aShType ) > (int)aDim )
+          continue;
+
+#ifdef WITH_SMESH_CANCEL_COMPUTE
+        if (_compute_canceled)
+          return false;
+        _sm_current = sm;
+#endif
+        sm->ComputeStateEngine( SMESH_subMesh::COMPUTE );
+#ifdef WITH_SMESH_CANCEL_COMPUTE
+        _sm_current = NULL;
+#endif
+        if ( aShapesId )
+          aShapesId->insert( sm->GetId() );
+      }
     }
-    else
-      smToCompute = 0;
+    // -----------------------------------------------
+    // mesh the rest sub-shapes starting from vertices
+    // -----------------------------------------------
+    ret = Compute( aMesh, aShape, /*anUpward=*/true, aDim, aShapesId );
   }
 
-  // -----------------------------------------------
-  // mesh the rest subshapes starting from vertices
-  // -----------------------------------------------
+  MESSAGE( "VSR - SMESH_Gen::Compute() finished, OK = " << ret);
+  MEMOSTAT;
 
-  int i, nbSub = smMap.size();
-  map<int, SMESH_subMesh*>::const_iterator itSub = smMap.begin();
-  for ( i = 0; i <= nbSub; ++i ) // loop on the whole map plus <sm>
+  SMESHDS_Mesh *myMesh = aMesh.GetMeshDS();
+  MESSAGE("*** compactMesh after compute");
+  myMesh->compactMesh();
+
+  // fix quadratic mesh by bending iternal links near concave boundary
+  if ( aShape.IsSame( aMesh.GetShapeToMesh() ) &&
+       !aShapesId && // not preview
+       ret ) // everything is OK
   {
-    if ( itSub == smMap.end() )
-      smToCompute = sm;
-    else
-      smToCompute = (itSub++)->second;
-    if (smToCompute->GetComputeState() != SMESH_subMesh::READY_TO_COMPUTE) {
-      if (smToCompute->GetComputeState() == SMESH_subMesh::FAILED_TO_COMPUTE)
-        ret = false;
-      continue;
-    }
-    TopoDS_Shape subShape = smToCompute->GetSubShape();
-    if ( subShape.ShapeType() != TopAbs_VERTEX )
+    SMESH_MesherHelper aHelper( aMesh );
+    if ( aHelper.IsQuadraticMesh() != SMESH_MesherHelper::LINEAR )
     {
-      if ( !smToCompute->ComputeStateEngine(SMESH_subMesh::COMPUTE) )
-        ret = false;
+      aHelper.FixQuadraticElements( sm->GetComputeError() );
     }
-    else
+  }
+  return ret;
+}
+
+
+#ifdef WITH_SMESH_CANCEL_COMPUTE
+//=============================================================================
+/*!
+ * Prepare Compute a mesh
+ */
+//=============================================================================
+void SMESH_Gen::PrepareCompute(SMESH_Mesh &          aMesh,
+                               const TopoDS_Shape &  aShape)
+{
+  _compute_canceled = false;
+  _sm_current = NULL;
+}
+//=============================================================================
+/*!
+ * Cancel Compute a mesh
+ */
+//=============================================================================
+void SMESH_Gen::CancelCompute(SMESH_Mesh &          aMesh,
+                              const TopoDS_Shape &  aShape)
+{
+  _compute_canceled = true;
+  if(_sm_current)
     {
-      TopoDS_Vertex V1 = TopoDS::Vertex(subShape);
-      gp_Pnt P1 = BRep_Tool::Pnt(V1);
-      SMESHDS_Mesh * meshDS = aMesh.GetMeshDS();
-      SMDS_MeshNode * node = meshDS->AddNode(P1.X(), P1.Y(), P1.Z());
-      if ( node ) {  // san - increase robustness
-        meshDS->SetNodeOnVertex(node, V1);
-        smToCompute->ComputeStateEngine(SMESH_subMesh::COMPUTE);
+      _sm_current->ComputeStateEngine( SMESH_subMesh::COMPUTE_CANCELED );
+    }
+}
+#endif
+
+//=============================================================================
+/*!
+ * Evaluate a mesh
+ */
+//=============================================================================
+
+bool SMESH_Gen::Evaluate(SMESH_Mesh &          aMesh,
+                         const TopoDS_Shape &  aShape,
+                         MapShapeNbElems&      aResMap,
+                         const bool            anUpward,
+                         TSetOfInt*            aShapesId)
+{
+  MESSAGE("SMESH_Gen::Evaluate");
+
+  bool ret = true;
+
+  SMESH_subMesh *sm = aMesh.GetSubMesh(aShape);
+
+  const bool includeSelf = true;
+  const bool complexShapeFirst = true;
+  SMESH_subMeshIteratorPtr smIt;
+
+  if ( anUpward ) { // is called from below code here
+    // -----------------------------------------------
+    // mesh all the sub-shapes starting from vertices
+    // -----------------------------------------------
+    smIt = sm->getDependsOnIterator(includeSelf, !complexShapeFirst);
+    while ( smIt->more() ) {
+      SMESH_subMesh* smToCompute = smIt->next();
+
+      // do not mesh vertices of a pseudo shape
+      const TopAbs_ShapeEnum aShType = smToCompute->GetSubShape().ShapeType();
+      //if ( !aMesh.HasShapeToMesh() && aShType == TopAbs_VERTEX )
+      //  continue;
+      if ( !aMesh.HasShapeToMesh() ) {
+        if( aShType == TopAbs_VERTEX || aShType == TopAbs_WIRE ||
+            aShType == TopAbs_SHELL )
+          continue;
       }
+
+      smToCompute->Evaluate(aResMap);
+      if( aShapesId )
+        aShapesId->insert( smToCompute->GetId() );
     }
+    return ret;
   }
+  else {
+    // -----------------------------------------------------------------
+    // apply algos that DO NOT require Discreteized boundaries and DO NOT
+    // support submeshes, starting from the most complex shapes
+    // and collect submeshes with algos that DO support submeshes
+    // -----------------------------------------------------------------
+    list< SMESH_subMesh* > smWithAlgoSupportingSubmeshes;
+    smIt = sm->getDependsOnIterator(includeSelf, complexShapeFirst);
+    while ( smIt->more() ) {
+      SMESH_subMesh* smToCompute = smIt->next();
+      const TopoDS_Shape& aSubShape = smToCompute->GetSubShape();
+      const int aShapeDim = GetShapeDim( aSubShape );
+      if ( aShapeDim < 1 ) break;
+      
+      SMESH_Algo* algo = GetAlgo( aMesh, aSubShape );
+      if ( algo && !algo->NeedDiscreteBoundary() ) {
+        if ( algo->SupportSubmeshes() ) {
+          smWithAlgoSupportingSubmeshes.push_front( smToCompute );
+        }
+        else {
+          smToCompute->Evaluate(aResMap);
+          if ( aShapesId )
+            aShapesId->insert( smToCompute->GetId() );
+        }
+      }
+    }
 
-  MESSAGE( "VSR - SMESH_Gen::Compute() finished, OK = " << ret);
+    // ------------------------------------------------------------
+    // sort list of meshes according to mesh order
+    // ------------------------------------------------------------
+    aMesh.SortByMeshOrder( smWithAlgoSupportingSubmeshes );
+
+    // ------------------------------------------------------------
+    // compute submeshes under shapes with algos that DO NOT require
+    // Discreteized boundaries and DO support submeshes
+    // ------------------------------------------------------------
+    list< SMESH_subMesh* >::iterator subIt, subEnd;
+    subIt  = smWithAlgoSupportingSubmeshes.begin();
+    subEnd = smWithAlgoSupportingSubmeshes.end();
+    // start from lower shapes
+    for ( ; subIt != subEnd; ++subIt ) {
+      sm = *subIt;
+
+      // get a shape the algo is assigned to
+      TopoDS_Shape algoShape;
+      if ( !GetAlgo( aMesh, sm->GetSubShape(), & algoShape ))
+        continue; // strange...
+
+      // look for more local algos
+      smIt = sm->getDependsOnIterator(!includeSelf, !complexShapeFirst);
+      while ( smIt->more() ) {
+        SMESH_subMesh* smToCompute = smIt->next();
+
+        const TopoDS_Shape& aSubShape = smToCompute->GetSubShape();
+        const int aShapeDim = GetShapeDim( aSubShape );
+        if ( aShapeDim < 1 ) continue;
+
+        //const TopAbs_ShapeEnum aShType = smToCompute->GetSubShape().ShapeType();
+
+        SMESH_HypoFilter filter( SMESH_HypoFilter::IsAlgo() );
+        filter
+          .And( SMESH_HypoFilter::IsApplicableTo( aSubShape ))
+          .And( SMESH_HypoFilter::IsMoreLocalThan( algoShape, aMesh ));
+
+        if ( SMESH_Algo* subAlgo = (SMESH_Algo*) aMesh.GetHypothesis( aSubShape, filter, true )) {
+          SMESH_Hypothesis::Hypothesis_Status status;
+          if ( subAlgo->CheckHypothesis( aMesh, aSubShape, status ))
+            // mesh a lower smToCompute starting from vertices
+            Evaluate( aMesh, aSubShape, aResMap, /*anUpward=*/true, aShapesId );
+        }
+      }
+    }
+    // ----------------------------------------------------------
+    // apply the algos that do not require Discreteized boundaries
+    // ----------------------------------------------------------
+    for ( subIt = smWithAlgoSupportingSubmeshes.begin(); subIt != subEnd; ++subIt )
+    {
+      sm = *subIt;
+      sm->Evaluate(aResMap);
+      if ( aShapesId )
+        aShapesId->insert( sm->GetId() );
+    }
+
+    // -----------------------------------------------
+    // mesh the rest sub-shapes starting from vertices
+    // -----------------------------------------------
+    ret = Evaluate( aMesh, aShape, aResMap, /*anUpward=*/true, aShapesId );
+  }
+
+  MESSAGE( "VSR - SMESH_Gen::Evaluate() finished, OK = " << ret);
   return ret;
 }
 
@@ -250,7 +562,7 @@ static bool checkConformIgnoredAlgos(SMESH_Mesh&               aMesh,
                                      const SMESH_Algo*         aGlobIgnoAlgo,
                                      const SMESH_Algo*         aLocIgnoAlgo,
                                      bool &                    checkConform,
-                                     map<int, SMESH_subMesh*>& aCheckedMap,
+                                     set<SMESH_subMesh*>&      aCheckedMap,
                                      list< SMESH_Gen::TAlgoStateError > & theErrors)
 {
   ASSERT( aSubMesh );
@@ -274,23 +586,29 @@ static bool checkConformIgnoredAlgos(SMESH_Mesh&               aMesh,
 
     if ( aLocIgnoAlgo ) // algo is hidden by a local algo of upper dim
     {
+      theErrors.push_back( SMESH_Gen::TAlgoStateError() );
+      theErrors.back().Set( SMESH_Hypothesis::HYP_HIDDEN_ALGO, algo, false );
       INFOS( "Local <" << algo->GetName() << "> is hidden by local <"
             << aLocIgnoAlgo->GetName() << ">");
     }
     else
     {
-      bool isGlobal = (aMesh.IsMainShape( aSubMesh->GetSubShape() ));
-      int dim = algo->GetDim();
+      bool       isGlobal = (aMesh.IsMainShape( aSubMesh->GetSubShape() ));
+      int             dim = algo->GetDim();
       int aMaxGlobIgnoDim = ( aGlobIgnoAlgo ? aGlobIgnoAlgo->GetDim() : -1 );
+      bool    isNeededDim = ( aGlobIgnoAlgo ? aGlobIgnoAlgo->NeedLowerHyps( dim ) : false );
 
-      if ( dim < aMaxGlobIgnoDim )
+      if (( dim < aMaxGlobIgnoDim && !isNeededDim ) &&
+          ( isGlobal || !aGlobIgnoAlgo->SupportSubmeshes() ))
       {
         // algo is hidden by a global algo
+        theErrors.push_back( SMESH_Gen::TAlgoStateError() );
+        theErrors.back().Set( SMESH_Hypothesis::HYP_HIDDEN_ALGO, algo, true );
         INFOS( ( isGlobal ? "Global" : "Local" )
               << " <" << algo->GetName() << "> is hidden by global <"
               << aGlobIgnoAlgo->GetName() << ">");
       }
-      else if ( !algo->NeedDescretBoundary() && !isGlobal)
+      else if ( !algo->NeedDiscreteBoundary() && !isGlobal)
       {
         // local algo is not hidden and hides algos on sub-shapes
         if (checkConform && !aSubMesh->IsConform( algo ))
@@ -301,23 +619,19 @@ static bool checkConformIgnoredAlgos(SMESH_Mesh&               aMesh,
                 "> would produce not conform mesh: "
                 "<Not Conform Mesh Allowed> hypotesis is missing");
           theErrors.push_back( SMESH_Gen::TAlgoStateError() );
-          theErrors.back().Set( SMESH_Gen::NOT_CONFORM_MESH, algo, false );
+          theErrors.back().Set( SMESH_Hypothesis::HYP_NOTCONFORM, algo, false );
         }
 
         // sub-algos will be hidden by a local <algo>
-        const map<int, SMESH_subMesh*>& smMap = aSubMesh->DependsOn();
-        map<int, SMESH_subMesh*>::const_reverse_iterator revItSub;
+        SMESH_subMeshIteratorPtr revItSub =
+          aSubMesh->getDependsOnIterator( /*includeSelf=*/false, /*complexShapeFirst=*/true);
         bool checkConform2 = false;
-        for ( revItSub = smMap.rbegin(); revItSub != smMap.rend(); revItSub++)
+        while ( revItSub->more() )
         {
-          checkConformIgnoredAlgos (aMesh, (*revItSub).second, aGlobIgnoAlgo,
+          SMESH_subMesh* sm = revItSub->next();
+          checkConformIgnoredAlgos (aMesh, sm, aGlobIgnoAlgo,
                                     algo, checkConform2, aCheckedMap, theErrors);
-          int key = (*revItSub).first;
-         SMESH_subMesh* sm = (*revItSub).second;
-          if ( aCheckedMap.find( key ) == aCheckedMap.end() )
-          {
-            aCheckedMap[ key ] = sm;
-          }
+          aCheckedMap.insert( sm );
         }
       }
     }
@@ -338,10 +652,18 @@ static bool checkMissing(SMESH_Gen*                aGen,
                          const int                 aTopAlgoDim,
                          bool*                     globalChecked,
                          const bool                checkNoAlgo,
-                         map<int, SMESH_subMesh*>& aCheckedMap,
+                         set<SMESH_subMesh*>&      aCheckedMap,
                          list< SMESH_Gen::TAlgoStateError > & theErrors)
 {
-  if ( aSubMesh->GetSubShape().ShapeType() == TopAbs_VERTEX)
+  switch ( aSubMesh->GetSubShape().ShapeType() )
+  {
+  case TopAbs_EDGE:
+  case TopAbs_FACE:
+  case TopAbs_SOLID: break; // check this submesh, it can be meshed
+  default:
+    return true; // not meshable submesh
+  }
+  if ( aCheckedMap.count( aSubMesh ))
     return true;
 
   //MESSAGE("=====checkMissing");
@@ -358,34 +680,54 @@ static bool checkMissing(SMESH_Gen*                aGen,
       int shapeDim = SMESH_Gen::GetShapeDim( aSubMesh->GetSubShape() );
       if (aTopAlgoDim > shapeDim)
       {
-        INFOS( "ERROR: " << shapeDim << "D algorithm is missing" );
+        MESSAGE( "ERROR: " << shapeDim << "D algorithm is missing" );
         ret = false;
         theErrors.push_back( SMESH_Gen::TAlgoStateError() );
-        theErrors.back().Set( SMESH_Gen::MISSING_ALGO, shapeDim, true );
+        theErrors.back().Set( SMESH_Hypothesis::HYP_MISSING, shapeDim, true );
       }
     }
     return ret;
   }
   case SMESH_subMesh::MISSING_HYP: {
     // notify if an algo missing hyp is attached to aSubMesh
-    algo = aGen->GetAlgo( aMesh, aSubMesh->GetSubShape() );
+    algo = aSubMesh->GetAlgo();
     ASSERT( algo );
     bool IsGlobalHypothesis = aGen->IsGlobalHypothesis( algo, aMesh );
     if (!IsGlobalHypothesis || !globalChecked[ algo->GetDim() ])
     {
-      INFOS( "ERROR: " << (IsGlobalHypothesis ? "Global " : "Local ")
-            << "<" << algo->GetName() << "> misses some hypothesis");
+      TAlgoStateErrorName errName = SMESH_Hypothesis::HYP_MISSING;
+      SMESH_Hypothesis::Hypothesis_Status status;
+      algo->CheckHypothesis( aMesh, aSubMesh->GetSubShape(), status );
+      if ( status == SMESH_Hypothesis::HYP_BAD_PARAMETER ) {
+        MESSAGE( "ERROR: hypothesis of " << (IsGlobalHypothesis ? "Global " : "Local ")
+                 << "<" << algo->GetName() << "> has a bad parameter value");
+        errName = status;
+      } else if ( status == SMESH_Hypothesis::HYP_BAD_GEOMETRY ) {
+        MESSAGE( "ERROR: " << (IsGlobalHypothesis ? "Global " : "Local ")
+                 << "<" << algo->GetName() << "> assigned to mismatching geometry");
+        errName = status;
+      } else {
+        MESSAGE( "ERROR: " << (IsGlobalHypothesis ? "Global " : "Local ")
+                 << "<" << algo->GetName() << "> misses some hypothesis");
+      }
       if (IsGlobalHypothesis)
         globalChecked[ algo->GetDim() ] = true;
       theErrors.push_back( SMESH_Gen::TAlgoStateError() );
-      theErrors.back().Set( SMESH_Gen::MISSING_HYPO, algo, IsGlobalHypothesis );
+      theErrors.back().Set( errName, algo, IsGlobalHypothesis );
     }
     ret = false;
     break;
   }
   case SMESH_subMesh::HYP_OK:
-    algo = aGen->GetAlgo( aMesh, aSubMesh->GetSubShape() );
+    algo = aSubMesh->GetAlgo();
     ret = true;
+    if (!algo->NeedDiscreteBoundary())
+    {
+      SMESH_subMeshIteratorPtr itsub = aSubMesh->getDependsOnIterator( /*includeSelf=*/false,
+                                                                       /*complexShapeFirst=*/false);
+      while ( itsub->more() )
+        aCheckedMap.insert( itsub->next() );
+    }
     break;
   default: ASSERT(0);
   }
@@ -395,18 +737,15 @@ static bool checkMissing(SMESH_Gen*                aGen,
   ASSERT (algo);
   bool isTopLocalAlgo =
     ( aTopAlgoDim <= algo->GetDim() && !aGen->IsGlobalHypothesis( algo, aMesh ));
-  if (!algo->NeedDescretBoundary() || isTopLocalAlgo)
+  if (!algo->NeedDiscreteBoundary() || isTopLocalAlgo)
   {
-    bool checkNoAlgo2 = ( algo->NeedDescretBoundary() );
-    const map<int, SMESH_subMesh*>& subMeshes = aSubMesh->DependsOn();
-    map<int, SMESH_subMesh*>::const_iterator itsub;
-    for (itsub = subMeshes.begin(); itsub != subMeshes.end(); itsub++)
+    bool checkNoAlgo2 = ( algo->NeedDiscreteBoundary() );
+    SMESH_subMeshIteratorPtr itsub = aSubMesh->getDependsOnIterator( /*includeSelf=*/false,
+                                                                     /*complexShapeFirst=*/true);
+    while ( itsub->more() )
     {
       // sub-meshes should not be checked further more
-      int key = (*itsub).first;
-      SMESH_subMesh* sm = (*itsub).second;
-      if ( aCheckedMap.find( key ) == aCheckedMap.end() )
-        aCheckedMap[ key ] = sm;
+      SMESH_subMesh* sm = itsub->next();
 
       if (isTopLocalAlgo)
       {
@@ -420,6 +759,7 @@ static bool checkMissing(SMESH_Gen*                aGen,
             checkNoAlgo2 = false;
         }
       }
+      aCheckedMap.insert( sm );
     }
   }
   return ret;
@@ -453,9 +793,9 @@ bool SMESH_Gen::GetAlgoState(SMESH_Mesh&               theMesh,
   bool ret = true;
   bool hasAlgo = false;
 
-  SMESH_subMesh* sm = theMesh.GetSubMesh(theShape);
+  SMESH_subMesh*          sm = theMesh.GetSubMesh(theShape);
   const SMESHDS_Mesh* meshDS = theMesh.GetMeshDS();
-  TopoDS_Shape mainShape = meshDS->ShapeToMesh();
+  TopoDS_Shape     mainShape = meshDS->ShapeToMesh();
 
   // -----------------
   // get global algos
@@ -482,57 +822,44 @@ bool SMESH_Gen::GetAlgoState(SMESH_Mesh&               theMesh,
 
   // --------------------------------------------------------
   // info on algos that will be ignored because of ones that
-  // don't NeedDescretBoundary() attached to super-shapes,
+  // don't NeedDiscreteBoundary() attached to super-shapes,
   // check that a conform mesh will be produced
   // --------------------------------------------------------
 
 
-  // find a global algo possibly hidding sub-algos
+  // find a global algo possibly hiding sub-algos
   int dim;
   const SMESH_Algo* aGlobIgnoAlgo = 0;
   for (dim = 3; dim > 0; dim--)
   {
     if (aGlobAlgoArr[ dim ] &&
-        !aGlobAlgoArr[ dim ]->NeedDescretBoundary())
+        !aGlobAlgoArr[ dim ]->NeedDiscreteBoundary() /*&&
+        !aGlobAlgoArr[ dim ]->SupportSubmeshes()*/ )
     {
       aGlobIgnoAlgo = aGlobAlgoArr[ dim ];
       break;
     }
   }
 
-  const map<int, SMESH_subMesh*>& smMap = sm->DependsOn();
-  map<int, SMESH_subMesh*>::const_reverse_iterator revItSub = smMap.rbegin();
-  map<int, SMESH_subMesh*> aCheckedMap;
+  set<SMESH_subMesh*> aCheckedSubs;
   bool checkConform = ( !theMesh.IsNotConformAllowed() );
-  int aKey = 1;
-  SMESH_subMesh* smToCheck = sm;
 
   // loop on theShape and its sub-shapes
-  while ( smToCheck )
+  SMESH_subMeshIteratorPtr revItSub = sm->getDependsOnIterator( /*includeSelf=*/true,
+                                                                /*complexShapeFirst=*/true);
+  while ( revItSub->more() )
   {
+    SMESH_subMesh* smToCheck = revItSub->next();
     if ( smToCheck->GetSubShape().ShapeType() == TopAbs_VERTEX)
       break;
 
-    if ( aCheckedMap.find( aKey ) == aCheckedMap.end() )
+    if ( aCheckedSubs.insert( smToCheck ).second ) // not yet checked
       if (!checkConformIgnoredAlgos (theMesh, smToCheck, aGlobIgnoAlgo,
-                                     0, checkConform, aCheckedMap, theErrors))
+                                     0, checkConform, aCheckedSubs, theErrors))
         ret = false;
 
     if ( smToCheck->GetAlgoState() != SMESH_subMesh::NO_ALGO )
       hasAlgo = true;
-
-    // next subMesh
-    if (revItSub != smMap.rend())
-    {
-      aKey = (*revItSub).first;
-      smToCheck = (*revItSub).second;
-      revItSub++;
-    }
-    else
-    {
-      smToCheck = 0;
-    }
-
   }
 
   // ----------------------------------------------------------------
@@ -552,43 +879,32 @@ bool SMESH_Gen::GetAlgoState(SMESH_Mesh&               theMesh,
       break;
     }
   }
-  aCheckedMap.clear();
-  smToCheck = sm;
-  revItSub = smMap.rbegin();
-  bool checkNoAlgo = (bool) aTopAlgoDim;
+  bool checkNoAlgo = theMesh.HasShapeToMesh() ? bool( aTopAlgoDim ) : false;
   bool globalChecked[] = { false, false, false, false };
 
   // loop on theShape and its sub-shapes
-  while ( smToCheck )
+  aCheckedSubs.clear();
+  revItSub = sm->getDependsOnIterator( /*includeSelf=*/true, /*complexShapeFirst=*/true);
+  while ( revItSub->more() )
   {
+    SMESH_subMesh* smToCheck = revItSub->next();
     if ( smToCheck->GetSubShape().ShapeType() == TopAbs_VERTEX)
       break;
 
-    if ( aCheckedMap.find( aKey ) == aCheckedMap.end() )
-      if (!checkMissing (this, theMesh, smToCheck, aTopAlgoDim,
-                         globalChecked, checkNoAlgo, aCheckedMap, theErrors))
-      {
-        ret = false;
-        if (smToCheck->GetAlgoState() == SMESH_subMesh::NO_ALGO )
-          checkNoAlgo = false;
-      }
-
-    // next subMesh
-    if (revItSub != smMap.rend())
+    if (!checkMissing (this, theMesh, smToCheck, aTopAlgoDim,
+                       globalChecked, checkNoAlgo, aCheckedSubs, theErrors))
     {
-      aKey = (*revItSub).first;
-      smToCheck = (*revItSub).second;
-      revItSub++;
+      ret = false;
+      if (smToCheck->GetAlgoState() == SMESH_subMesh::NO_ALGO )
+        checkNoAlgo = false;
     }
-    else
-      smToCheck = 0;
   }
 
   if ( !hasAlgo ) {
     ret = false;
     INFOS( "None algorithm attached" );
     theErrors.push_back( TAlgoStateError() );
-    theErrors.back().Set( MISSING_ALGO, 1, true );
+    theErrors.back().Set( SMESH_Hypothesis::HYP_MISSING, 1, true );
   }
 
   return ret;
@@ -605,92 +921,273 @@ bool SMESH_Gen::IsGlobalHypothesis(const SMESH_Hypothesis* theHyp, SMESH_Mesh& a
   return aMesh.GetHypothesis( aMesh.GetMeshDS()->ShapeToMesh(), filter, false );
 }
 
-//=============================================================================
+//================================================================================
 /*!
- *
+ * \brief Return paths to xml files of plugins
  */
-//=============================================================================
+//================================================================================
 
-SMESH_Algo *SMESH_Gen::GetAlgo(SMESH_Mesh & aMesh, const TopoDS_Shape & aShape)
+std::vector< std::string > SMESH_Gen::GetPluginXMLPaths()
 {
-//  MESSAGE("SMESH_Gen::GetAlgo");
+  // Get paths to xml files of plugins
+  vector< string > xmlPaths;
+  string sep;
+  if ( const char* meshersList = getenv("SMESH_MeshersList") )
+  {
+    string meshers = meshersList, plugin;
+    string::size_type from = 0, pos;
+    while ( from < meshers.size() )
+    {
+      // cut off plugin name
+      pos = meshers.find( ':', from );
+      if ( pos != string::npos )
+        plugin = meshers.substr( from, pos-from );
+      else
+        plugin = meshers.substr( from ), pos = meshers.size();
+      from = pos + 1;
+
+      // get PLUGIN_ROOT_DIR path
+      string rootDirVar, pluginSubDir = plugin;
+      if ( plugin == "StdMeshers" )
+        rootDirVar = "SMESH", pluginSubDir = "smesh";
+      else
+        for ( pos = 0; pos < plugin.size(); ++pos )
+          rootDirVar += toupper( plugin[pos] );
+      rootDirVar += "_ROOT_DIR";
+
+      const char* rootDir = getenv( rootDirVar.c_str() );
+      if ( !rootDir || strlen(rootDir) == 0 )
+      {
+        rootDirVar = plugin + "_ROOT_DIR"; // HexoticPLUGIN_ROOT_DIR
+        rootDir = getenv( rootDirVar.c_str() );
+        if ( !rootDir || strlen(rootDir) == 0 ) continue;
+      }
 
-  SMESH_HypoFilter filter( SMESH_HypoFilter::IsAlgo() );
-  filter.And( filter.IsApplicableTo( aShape ));
+      // get a separator from rootDir
+      for ( pos = strlen( rootDir )-1; pos >= 0 && sep.empty(); --pos )
+        if ( rootDir[pos] == '/' || rootDir[pos] == '\\' )
+        {
+          sep = rootDir[pos];
+          break;
+        }
+#ifdef WNT
+      if (sep.empty() ) sep = "\\";
+#else
+      if (sep.empty() ) sep = "/";
+#endif
+
+      // get a path to resource file
+      string xmlPath = rootDir;
+      if ( xmlPath[ xmlPath.size()-1 ] != sep[0] )
+        xmlPath += sep;
+      xmlPath += "share" + sep + "salome" + sep + "resources" + sep;
+      for ( pos = 0; pos < pluginSubDir.size(); ++pos )
+        xmlPath += tolower( pluginSubDir[pos] );
+      xmlPath += sep + plugin + ".xml";
+      bool fileOK;
+#ifdef WNT
+      fileOK = (GetFileAttributes(xmlPath.c_str()) != INVALID_FILE_ATTRIBUTES);
+#else
+      fileOK = (access(xmlPath.c_str(), F_OK) == 0);
+#endif
+      if ( fileOK )
+        xmlPaths.push_back( xmlPath );
+    }
+  }
 
-  list <const SMESHDS_Hypothesis * > algoList;
-  aMesh.GetHypotheses( aShape, filter, algoList, true );
+  return xmlPaths;
+}
 
-  if ( algoList.empty() )
-    return NULL;
+//=======================================================================
+namespace // Access to type of input and output of an algorithm
+//=======================================================================
+{
+  struct AlgoData
+  {
+    int                       _dim;
+    set<SMDSAbs_GeometryType> _inElemTypes; // acceptable types of input mesh element
+    set<SMDSAbs_GeometryType> _outElemTypes; // produced types of mesh elements
 
-  // Now it is checked in SMESH_Mesh::GetHypotheses()
-//   if (algoList.size() > 1 ) { // check if there is one algo several times
-//     list <const SMESHDS_Hypothesis * >::iterator algo = algoList.begin();
-//     for ( ; algo != algoList.end(); ++algo )
-//       if ( (*algo) != algoList.front() &&
-//            (*algo)->GetName() != algoList.front()->GetName() )
-//         return NULL;
-//   }
+    bool IsCompatible( const AlgoData& algo2 ) const
+    {
+      if ( _dim > algo2._dim ) return algo2.IsCompatible( *this );
+      // algo2 is of highter dimension
+      if ( _outElemTypes.empty() || algo2._inElemTypes.empty() )
+        return false;
+      bool compatible = true;
+      set<SMDSAbs_GeometryType>::const_iterator myOutType = _outElemTypes.begin();
+      for ( ; myOutType != _outElemTypes.end() && compatible; ++myOutType )
+        compatible = algo2._inElemTypes.count( *myOutType );
+      return compatible;
+    }
+  };
+
+  //================================================================================
+  /*!
+   * \brief Return AlgoData of the algorithm
+   */
+  //================================================================================
 
-  return const_cast<SMESH_Algo*> ( static_cast<const SMESH_Algo* >( algoList.front() ));
+  const AlgoData& getAlgoData( const SMESH_Algo* algo )
+  {
+    static map< string, AlgoData > theDataByName;
+    if ( theDataByName.empty() )
+    {
+      // Read Plugin.xml files
+      vector< string > xmlPaths = SMESH_Gen::GetPluginXMLPaths();
+      LDOMParser xmlParser;
+      for ( size_t iXML = 0; iXML < xmlPaths.size(); ++iXML )
+      {
+        bool error = xmlParser.parse( xmlPaths[iXML].c_str() );
+        if ( error )
+        {
+          TCollection_AsciiString data;
+          INFOS( xmlParser.GetError(data) );
+          continue;
+        }
+        // <algorithm type="Regular_1D"
+        //            ...
+        //            input="EDGE"
+        //            output="QUAD,TRIA">
+        //
+        LDOM_Document xmlDoc = xmlParser.getDocument();
+        LDOM_NodeList algoNodeList = xmlDoc.getElementsByTagName( "algorithm" );
+        for ( int i = 0; i < algoNodeList.getLength(); ++i )
+        {
+          LDOM_Node     algoNode           = algoNodeList.item( i );
+          LDOM_Element& algoElem           = (LDOM_Element&) algoNode;
+          TCollection_AsciiString algoType = algoElem.getAttribute("type");
+          TCollection_AsciiString input    = algoElem.getAttribute("input");
+          TCollection_AsciiString output   = algoElem.getAttribute("output");
+          TCollection_AsciiString dim      = algoElem.getAttribute("dim");
+          if ( algoType.IsEmpty() ) continue;
+          AlgoData & data                  = theDataByName[ algoType.ToCString() ];
+          data._dim = dim.IntegerValue();
+          for ( int isInput = 0; isInput < 2; ++isInput )
+          {
+            TCollection_AsciiString&   typeStr = isInput ? input : output;
+            set<SMDSAbs_GeometryType>& typeSet = isInput ? data._inElemTypes : data._outElemTypes;
+            int beg = 1, end;
+            while ( beg <= typeStr.Length() )
+            {
+              while ( beg < typeStr.Length() && !isalpha( typeStr.Value( beg ) ))
+                ++beg;
+              end = beg;
+              while ( end < typeStr.Length() && isalpha( typeStr.Value( end + 1 ) ))
+                ++end;
+              if ( end > beg )
+              {
+                TCollection_AsciiString typeName = typeStr.SubString( beg, end );
+                if      ( typeName == "EDGE" ) typeSet.insert( SMDSGeom_EDGE );
+                else if ( typeName == "TRIA" ) typeSet.insert( SMDSGeom_TRIANGLE );
+                else if ( typeName == "QUAD" ) typeSet.insert( SMDSGeom_QUADRANGLE );
+              }
+              beg = end + 1;
+            }
+          }
+        }
+      }
+    }
+    return theDataByName[ algo->GetName() ];
+  }
 }
 
 //=============================================================================
 /*!
- *
+ * Finds algo to mesh a shape. Optionally returns a shape the found algo is bound to
  */
 //=============================================================================
 
-StudyContextStruct *SMESH_Gen::GetStudyContext(int studyId)
+SMESH_Algo *SMESH_Gen::GetAlgo(SMESH_Mesh &         aMesh,
+                               const TopoDS_Shape & aShape,
+                               TopoDS_Shape*        assignedTo)
 {
-       // Get studyContext, create it if it does'nt exist, with a SMESHDS_Document
-
-       if (_mapStudyContext.find(studyId) == _mapStudyContext.end())
-       {
-               _mapStudyContext[studyId] = new StudyContextStruct;
-               _mapStudyContext[studyId]->myDocument = new SMESHDS_Document(studyId);
-       }
-       StudyContextStruct *myStudyContext = _mapStudyContext[studyId];
-//   ASSERT(_mapStudyContext.find(studyId) != _mapStudyContext.end());
-       return myStudyContext;
-}
+  SMESH_HypoFilter filter( SMESH_HypoFilter::IsAlgo() );
+  filter.And( filter.IsApplicableTo( aShape ));
 
-//=============================================================================
-/*!
- *
- */
-//=============================================================================
+  TopoDS_Shape assignedToShape;
+  SMESH_Algo* algo =
+    (SMESH_Algo*) aMesh.GetHypothesis( aShape, filter, true, &assignedToShape );
 
-void SMESH_Gen::Save(int studyId, const char *aUrlOfFile)
-{
-}
+  if ( algo &&
+       aShape.ShapeType() == TopAbs_FACE &&
+       !aShape.IsSame( assignedToShape ) &&
+       SMESH_MesherHelper::NbAncestors( aShape, aMesh, TopAbs_SOLID ) > 1 )
+  {
+    // Issue 0021559. If there is another 2D algo with different types of output
+    // elements that can be used to mesh aShape, and 3D algos on adjacent SOLIDs
+    // have different types of input elements, we choose a most appropriate 2D algo.
+
+    // try to find a concurrent 2D algo
+    filter.AndNot( filter.Is( algo ));
+    TopoDS_Shape assignedToShape2;
+    SMESH_Algo* algo2 =
+      (SMESH_Algo*) aMesh.GetHypothesis( aShape, filter, true, &assignedToShape2 );
+    if ( algo2 &&                                                  // algo found
+         !assignedToShape2.IsSame( aMesh.GetShapeToMesh() ) &&     // algo is local
+         ( SMESH_MesherHelper::GetGroupType( assignedToShape2 ) == // algo of the same level
+           SMESH_MesherHelper::GetGroupType( assignedToShape )) &&
+         aMesh.IsOrderOK( aMesh.GetSubMesh( assignedToShape2 ),    // no forced order
+                          aMesh.GetSubMesh( assignedToShape  )))
+    {
+      // get algos on the adjacent SOLIDs
+      filter.Init( filter.IsAlgo() ).And( filter.HasDim( 3 ));
+      vector< SMESH_Algo* > algos3D;
+      PShapeIteratorPtr solidIt = SMESH_MesherHelper::GetAncestors( aShape, aMesh,
+                                                                    TopAbs_SOLID );
+      while ( const TopoDS_Shape* solid = solidIt->next() )
+        if ( SMESH_Algo* algo3D = (SMESH_Algo*) aMesh.GetHypothesis( *solid, filter, true ))
+        {
+          algos3D.push_back( algo3D );
+          filter.AndNot( filter.HasName( algo3D->GetName() ));
+        }
+      // check compatibility of algos
+      if ( algos3D.size() > 1 )
+      {
+        const AlgoData& algoData    = getAlgoData( algo );
+        const AlgoData& algoData2   = getAlgoData( algo2 );
+        const AlgoData& algoData3d0 = getAlgoData( algos3D[0] );
+        const AlgoData& algoData3d1 = getAlgoData( algos3D[1] );
+        if (( algoData2.IsCompatible( algoData3d0 ) &&
+              algoData2.IsCompatible( algoData3d1 ))
+            &&
+            !(algoData.IsCompatible( algoData3d0 ) &&
+              algoData.IsCompatible( algoData3d1 )))
+          algo = algo2;
+      }
+    }
+  }
 
-//=============================================================================
-/*!
- *
- */
-//=============================================================================
+  if ( assignedTo && algo )
+    * assignedTo = assignedToShape;
 
-void SMESH_Gen::Load(int studyId, const char *aUrlOfFile)
-{
+  return algo;
 }
 
 //=============================================================================
 /*!
- *
+ * Returns StudyContextStruct for a study
  */
 //=============================================================================
 
-void SMESH_Gen::Close(int studyId)
+StudyContextStruct *SMESH_Gen::GetStudyContext(int studyId)
 {
+  // Get studyContext, create it if it does'nt exist, with a SMESHDS_Document
+
+  if (_mapStudyContext.find(studyId) == _mapStudyContext.end())
+  {
+    _mapStudyContext[studyId] = new StudyContextStruct;
+    _mapStudyContext[studyId]->myDocument = new SMESHDS_Document(studyId);
+  }
+  StudyContextStruct *myStudyContext = _mapStudyContext[studyId];
+  return myStudyContext;
 }
 
-//=============================================================================
+//================================================================================
 /*!
- *
+ * \brief Return shape dimension by TopAbs_ShapeEnum
  */
-//=============================================================================
+//================================================================================
 
 int SMESH_Gen::GetShapeDim(const TopAbs_ShapeEnum & aShapeType)
 {
@@ -698,26 +1195,25 @@ int SMESH_Gen::GetShapeDim(const TopAbs_ShapeEnum & aShapeType)
   if ( dim.empty() )
   {
     dim.resize( TopAbs_SHAPE, -1 );
-    dim[ TopAbs_COMPOUND ]  = 3;
-    dim[ TopAbs_COMPSOLID ] = 3;
-    dim[ TopAbs_SOLID ]     = 3;
-    dim[ TopAbs_SHELL ]     = 3;
-    dim[ TopAbs_FACE  ]     = 2;
-    dim[ TopAbs_WIRE ]      = 1;
-    dim[ TopAbs_EDGE ]      = 1;
-    dim[ TopAbs_VERTEX ]    = 0;
+    dim[ TopAbs_COMPOUND ]  = MeshDim_3D;
+    dim[ TopAbs_COMPSOLID ] = MeshDim_3D;
+    dim[ TopAbs_SOLID ]     = MeshDim_3D;
+    dim[ TopAbs_SHELL ]     = MeshDim_2D;
+    dim[ TopAbs_FACE  ]     = MeshDim_2D;
+    dim[ TopAbs_WIRE ]      = MeshDim_1D;
+    dim[ TopAbs_EDGE ]      = MeshDim_1D;
+    dim[ TopAbs_VERTEX ]    = MeshDim_0D;
   }
   return dim[ aShapeType ];
 }
 
 //=============================================================================
 /*!
- *
+ * Genarate a new id unique withing this Gen
  */
 //=============================================================================
 
 int SMESH_Gen::GetANewId()
 {
-       //MESSAGE("SMESH_Gen::GetANewId");
-       return _hypId++;
+  return _hypId++;
 }