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52447: Re-compute fails after hypothesis modification
[modules/smesh.git] / src / SMESH / SMESH_subMesh.cxx
index 6c484c80a20e6d9eff3ddef37a83010a4532a7c4..4da6bf9ffda286faae4ac101d6de3d94caaca1d2 100644 (file)
@@ -1,30 +1,30 @@
-//  Copyright (C) 2007-2008  CEA/DEN, EDF R&D, OPEN CASCADE
+// Copyright (C) 2007-2014  CEA/DEN, EDF R&D, OPEN CASCADE
 //
-//  Copyright (C) 2003-2007  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, 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
-//  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
+// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
 //
+
 //  SMESH SMESH : implementaion of SMESH idl descriptions
 //  File   : SMESH_subMesh.cxx
 //  Author : Paul RASCLE, EDF
 //  Module : SMESH
-//  $Header$
-//
+
 #include "SMESH_subMesh.hxx"
 
 #include "SMESH_Algo.hxx"
 #include "SMESH_subMeshEventListener.hxx"
 #include "SMESH_Comment.hxx"
 #include "SMDS_SetIterator.hxx"
+#include "SMDSAbs_ElementType.hxx"
+
+#include <Basics_OCCTVersion.hxx>
 
 #include "utilities.h"
 #include "OpUtil.hxx"
+#include "Basics_Utils.hxx"
 
 #include <BRep_Builder.hxx>
 #include <BRep_Tool.hxx>
@@ -54,6 +58,8 @@
 #include <Standard_OutOfMemory.hxx>
 #include <Standard_ErrorHandler.hxx>
 
+#include <numeric>
+
 using namespace std;
 
 //=============================================================================
@@ -82,22 +88,24 @@ SMESH_subMesh::SMESH_subMesh(int                  Id,
                              SMESHDS_Mesh *       meshDS,
                              const TopoDS_Shape & aSubShape)
 {
-       _subShape = aSubShape;
-       _subMeshDS = meshDS->MeshElements(_subShape);   // may be null ...
-       _father = father;
-       _Id = Id;
-       _dependenceAnalysed = _alwaysComputed = false;
-
-       if (_subShape.ShapeType() == TopAbs_VERTEX)
-       {
-               _algoState = HYP_OK;
-               _computeState = READY_TO_COMPUTE;
-       }
-       else
-       {
-          _algoState = NO_ALGO;
-          _computeState = NOT_READY;
-       }
+  _subShape           = aSubShape;
+  _subMeshDS          = meshDS->MeshElements(_subShape);   // may be null ...
+  _father             = father;
+  _Id                 = Id;
+  _dependenceAnalysed = _alwaysComputed = false;
+  _algo               = 0;
+  if (_subShape.ShapeType() == TopAbs_VERTEX)
+  {
+    _algoState = HYP_OK;
+    _computeState = READY_TO_COMPUTE;
+  }
+  else
+  {
+    _algoState = NO_ALGO;
+    _computeState = NOT_READY;
+  }
+  _computeCost = 0; // how costly is to compute this sub-mesh
+  _realComputeCost = 0;
 }
 
 //=============================================================================
@@ -108,9 +116,7 @@ SMESH_subMesh::SMESH_subMesh(int                  Id,
 
 SMESH_subMesh::~SMESH_subMesh()
 {
-  MESSAGE("SMESH_subMesh::~SMESH_subMesh");
-  // ****
-  DeleteOwnListeners();
+  deleteOwnListeners();
 }
 
 //=============================================================================
@@ -143,6 +149,17 @@ SMESHDS_SubMesh * SMESH_subMesh::GetSubMeshDS()
  */
 //=============================================================================
 
+const SMESHDS_SubMesh * SMESH_subMesh::GetSubMeshDS() const
+{
+  return ((SMESH_subMesh*) this )->GetSubMeshDS();
+}
+
+//=============================================================================
+/*!
+ *
+ */
+//=============================================================================
+
 SMESHDS_SubMesh* SMESH_subMesh::CreateSubMeshDS()
 {
   if ( !GetSubMeshDS() ) {
@@ -171,7 +188,20 @@ SMESH_subMesh *SMESH_subMesh::GetFirstToCompute()
 
 //================================================================================
 /*!
- * \brief Allow algo->Compute() if a subshape of lower dim is meshed but
+ * \brief Returns a current algorithm
+ */
+//================================================================================
+
+SMESH_Algo* SMESH_subMesh::GetAlgo() const
+{
+  if ( !_algo )
+    ((SMESH_subMesh*)this)->_algo = _father->GetGen()->GetAlgo(*_father, _subShape);
+  return _algo;
+}
+
+//================================================================================
+/*!
+ * \brief Allow algo->Compute() if a sub-shape of lower dim is meshed but
  *        none mesh entity is bound to it (PAL13615, 2nd part)
  */
 //================================================================================
@@ -236,15 +266,16 @@ bool SMESH_subMesh::IsMeshComputed() const
 
 //=============================================================================
 /*!
- *
+ * Return true if all sub-meshes have been meshed
  */
 //=============================================================================
 
-bool SMESH_subMesh::SubMeshesComputed()
+bool SMESH_subMesh::SubMeshesComputed(bool * isFailedToCompute/*=0*/) const
 {
   int myDim = SMESH_Gen::GetShapeDim( _subShape );
   int dimToCheck = myDim - 1;
   bool subMeshesComputed = true;
+  if ( isFailedToCompute ) *isFailedToCompute = false;
   // check subMeshes with upper dimension => reverse iteration
   SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,true);
   while ( smIt->more() )
@@ -253,95 +284,143 @@ bool SMESH_subMesh::SubMeshesComputed()
     if ( sm->_alwaysComputed )
       continue;
     const TopoDS_Shape & ss = sm->GetSubShape();
+
     // MSV 07.04.2006: restrict checking to myDim-1 only. Ex., there is no sense
     // in checking of existence of edges if the algo needs only faces. Moreover,
     // degenerated edges may have no submesh, as after computing NETGEN_2D.
-    int dim = SMESH_Gen::GetShapeDim( ss );
-    if (dim < dimToCheck)
-      break; // the rest subMeshes are all of less dimension
+    if ( !_algo || _algo->NeedDiscreteBoundary() ) {
+      int dim = SMESH_Gen::GetShapeDim( ss );
+      if (dim < dimToCheck)
+        break; // the rest subMeshes are all of less dimension
+    }
     SMESHDS_SubMesh * ds = sm->GetSubMeshDS();
     bool computeOk = (sm->GetComputeState() == COMPUTE_OK ||
-                      (ds && ( ds->NbNodes() || ds->NbElements() )));
+                      (ds && ( dimToCheck ? ds->NbElements() : ds->NbNodes()  )));
     if (!computeOk)
     {
-      int type = ss.ShapeType();
-
       subMeshesComputed = false;
-
-      switch (type)
-      {
-      case TopAbs_COMPOUND:
-        {
-          MESSAGE("The not computed sub mesh is a COMPOUND");
-          break;
-        }
-      case TopAbs_COMPSOLID:
-        {
-          MESSAGE("The not computed sub mesh is a COMPSOLID");
-          break;
-        }
-      case TopAbs_SHELL:
-        {
-          MESSAGE("The not computed sub mesh is a SHEL");
-          break;
-        }
-      case TopAbs_WIRE:
-        {
-          MESSAGE("The not computed sub mesh is a WIRE");
-          break;
-        }
-      case TopAbs_SOLID:
-        {
-          MESSAGE("The not computed sub mesh is a SOLID");
-          break;
-        }
-      case TopAbs_FACE:
-        {
-          MESSAGE("The not computed sub mesh is a FACE");
-          break;
-        }
-      case TopAbs_EDGE:
-        {
-          MESSAGE("The not computed sub mesh is a EDGE");
-          break;
-        }
-      default:
-        {
-          MESSAGE("The not computed sub mesh is of unknown type");
-          break;
-        }
-      }
-
-      break;
+      if ( isFailedToCompute && !(*isFailedToCompute) )
+        *isFailedToCompute = ( sm->GetComputeState() == FAILED_TO_COMPUTE );
+
+      // int type = ss.ShapeType();
+
+      // switch (type)
+      // {
+      // case TopAbs_COMPOUND:
+      //   {
+      //     MESSAGE("The not computed sub mesh is a COMPOUND");
+      //     break;
+      //   }
+      // case TopAbs_COMPSOLID:
+      //   {
+      //     MESSAGE("The not computed sub mesh is a COMPSOLID");
+      //     break;
+      //   }
+      // case TopAbs_SHELL:
+      //   {
+      //     MESSAGE("The not computed sub mesh is a SHEL");
+      //     break;
+      //   }
+      // case TopAbs_WIRE:
+      //   {
+      //     MESSAGE("The not computed sub mesh is a WIRE");
+      //     break;
+      //   }
+      // case TopAbs_SOLID:
+      //   {
+      //     MESSAGE("The not computed sub mesh is a SOLID");
+      //     break;
+      //   }
+      // case TopAbs_FACE:
+      //   {
+      //     MESSAGE("The not computed sub mesh is a FACE");
+      //     break;
+      //   }
+      // case TopAbs_EDGE:
+      //   {
+      //     MESSAGE("The not computed sub mesh is a EDGE");
+      //     break;
+      //   }
+      // default:
+      //   {
+      //     MESSAGE("The not computed sub mesh is of unknown type");
+      //     break;
+      //   }
+      // }
+
+      if ( !isFailedToCompute )
+        break;
     }
   }
   return subMeshesComputed;
 }
 
-//=============================================================================
+//================================================================================
 /*!
- *
+ * \brief Return cost of computing this sub-mesh. If hypotheses are not well defined,
+ *        zero is returned
+ *  \return int - the computation cost in abstract units.
  */
-//=============================================================================
+//================================================================================
 
-bool SMESH_subMesh::SubMeshesReady()
+int SMESH_subMesh::GetComputeCost() const
 {
-  bool subMeshesReady = true;
-  SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,true);
-  while ( smIt->more() ) {
-    SMESH_subMesh *sm = smIt->next();
-    bool computeOk = (sm->GetComputeState() == COMPUTE_OK ||
-                      sm->GetComputeState() == READY_TO_COMPUTE);
-    if (!computeOk)
-    {
-      subMeshesReady = false;
-      SCRUTE(sm->GetId());
-      break;
+  return _realComputeCost;
+}
+
+//================================================================================
+/*!
+ * \brief Return cost of computing this sub-mesh. The cost depends on the shape type
+ *        and number of sub-meshes this one DependsOn().
+ *  \return int - the computation cost in abstract units.
+ */
+//================================================================================
+
+int SMESH_subMesh::computeCost() const
+{
+  if ( !_computeCost )
+  {
+    int computeCost;
+    switch ( _subShape.ShapeType() ) {
+    case TopAbs_SOLID:
+    case TopAbs_SHELL: computeCost = 5000; break;
+    case TopAbs_FACE:  computeCost = 500; break;
+    case TopAbs_EDGE:  computeCost = 2; break;
+    default:           computeCost = 1;
     }
+    SMESH_subMeshIteratorPtr childIt = getDependsOnIterator(/*includeSelf=*/false);
+    while ( childIt->more() )
+      computeCost += childIt->next()->computeCost();
+
+    ((SMESH_subMesh*)this)->_computeCost = computeCost;
   }
-  return subMeshesReady;
+  return _computeCost;
 }
 
+//=============================================================================
+/*!
+ *
+ */
+//=============================================================================
+
+// bool SMESH_subMesh::SubMeshesReady()
+// {
+//   bool subMeshesReady = true;
+//   SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,true);
+//   while ( smIt->more() ) {
+//     SMESH_subMesh *sm = smIt->next();
+//     bool computeOk = (sm->GetComputeState() == COMPUTE_OK ||
+//                       sm->GetComputeState() == READY_TO_COMPUTE);
+//     if (!computeOk)
+//     {
+//       subMeshesReady = false;
+//       SCRUTE(sm->GetId());
+//       break;
+//     }
+//   }
+//   return subMeshesReady;
+// }
+
 //=============================================================================
 /*!
  * Construct dependence on first level subMeshes. complex shapes (compsolid,
@@ -368,55 +447,57 @@ const map < int, SMESH_subMesh * >& SMESH_subMesh::DependsOn()
   case TopAbs_COMPOUND:
     {
       //MESSAGE("compound");
-      for (TopExp_Explorer exp(_subShape, TopAbs_SOLID); exp.More();
-           exp.Next())
+      for (TopExp_Explorer exp(_subShape, TopAbs_SOLID); exp.More();exp.Next())
       {
-        InsertDependence(exp.Current());
+        insertDependence(exp.Current());
       }
-      for (TopExp_Explorer exp(_subShape, TopAbs_SHELL, TopAbs_SOLID); exp.More();
-           exp.Next())
+      for (TopExp_Explorer exp(_subShape, TopAbs_SHELL, TopAbs_SOLID); exp.More(); exp.Next())
       {
-          InsertDependence(exp.Current());      //only shell not in solid
+        if ( BRep_Tool::IsClosed(exp.Current() ))
+          insertDependence(exp.Current());      //only shell not in solid
+        else
+          for (TopExp_Explorer expF(exp.Current(), TopAbs_FACE); expF.More();expF.Next())
+            insertDependence(expF.Current());    // issue 0020959: HEXA_3D fails on shell
+
       }
-      for (TopExp_Explorer exp(_subShape, TopAbs_FACE, TopAbs_SHELL); exp.More();
-           exp.Next())
+      for (TopExp_Explorer exp(_subShape, TopAbs_FACE, TopAbs_SHELL); exp.More();exp.Next())
       {
-        InsertDependence(exp.Current());
+        insertDependence(exp.Current());
       }
-      for (TopExp_Explorer exp(_subShape, TopAbs_EDGE, TopAbs_FACE); exp.More();
-           exp.Next())
+      for (TopExp_Explorer exp(_subShape, TopAbs_EDGE, TopAbs_FACE); exp.More();exp.Next())
       {
-        InsertDependence(exp.Current());
+        insertDependence(exp.Current());
+      }
+      for (TopExp_Explorer exp(_subShape, TopAbs_VERTEX, TopAbs_EDGE); exp.More();exp.Next())
+      {
+        insertDependence(exp.Current());
       }
       break;
     }
   case TopAbs_COMPSOLID:
     {
-               //MESSAGE("compsolid");
-      for (TopExp_Explorer exp(_subShape, TopAbs_SOLID); exp.More();
-           exp.Next())
+      //MESSAGE("compsolid");
+      for (TopExp_Explorer exp(_subShape, TopAbs_SOLID); exp.More(); exp.Next())
       {
-        InsertDependence(exp.Current());
+        insertDependence(exp.Current());
       }
       break;
     }
   case TopAbs_SHELL:
     {
       //MESSAGE("shell");
-      for (TopExp_Explorer exp(_subShape, TopAbs_FACE); exp.More();
-           exp.Next())
+      for (TopExp_Explorer exp(_subShape, TopAbs_FACE); exp.More(); exp.Next())
       {
-        InsertDependence(exp.Current());
+        insertDependence(exp.Current());
       }
       break;
     }
   case TopAbs_WIRE:
     {
       //MESSAGE("wire");
-      for (TopExp_Explorer exp(_subShape, TopAbs_EDGE); exp.More();
-           exp.Next())
+      for (TopExp_Explorer exp(_subShape, TopAbs_EDGE); exp.More(); exp.Next())
       {
-        InsertDependence(exp.Current());
+        insertDependence(exp.Current());
       }
       break;
     }
@@ -424,10 +505,9 @@ const map < int, SMESH_subMesh * >& SMESH_subMesh::DependsOn()
     {
       //MESSAGE("solid");
       if(_father->HasShapeToMesh()) {
-        for (TopExp_Explorer exp(_subShape, TopAbs_FACE); exp.More();
-             exp.Next())
+        for (TopExp_Explorer exp(_subShape, TopAbs_FACE); exp.More();exp.Next())
         {
-          InsertDependence(exp.Current());
+          insertDependence(exp.Current());
         }
       }
       break;
@@ -435,21 +515,19 @@ const map < int, SMESH_subMesh * >& SMESH_subMesh::DependsOn()
   case TopAbs_FACE:
     {
       //MESSAGE("face");
-      for (TopExp_Explorer exp(_subShape, TopAbs_EDGE); exp.More();
-           exp.Next())
+      for (TopExp_Explorer exp(_subShape, TopAbs_EDGE); exp.More();exp.Next())
       {
-        InsertDependence(exp.Current());
+        insertDependence(exp.Current());
       }
       break;
     }
   case TopAbs_EDGE:
     {
       //MESSAGE("edge");
-      for (TopExp_Explorer exp(_subShape, TopAbs_VERTEX); exp.More();
-           exp.Next())
+      for (TopExp_Explorer exp(_subShape, TopAbs_VERTEX); exp.More(); exp.Next())
       {
-                       InsertDependence(exp.Current());
-                      }
+        insertDependence(exp.Current());
+      }
       break;
     }
   case TopAbs_VERTEX:
@@ -465,20 +543,33 @@ const map < int, SMESH_subMesh * >& SMESH_subMesh::DependsOn()
   return _mapDepend;
 }
 
+//================================================================================
+/*!
+ * \brief Return a key for SMESH_subMesh::_mapDepend map
+ */
+//================================================================================
+
+namespace {
+  int dependsOnMapKey( const SMESH_subMesh* sm )
+  {
+    int type = sm->GetSubShape().ShapeType();
+    int ordType = 9 - type;               // 2 = Vertex, 8 = CompSolid
+    int cle = sm->GetId();
+    cle += 10000000 * ordType;    // sort map by ordType then index
+    return cle;
+  }
+}
+
 //=============================================================================
 /*!
  * For simple Shapes (solid, face, edge): add subMesh into dependence list.
  */
 //=============================================================================
 
-void SMESH_subMesh::InsertDependence(const TopoDS_Shape aSubShape)
+void SMESH_subMesh::insertDependence(const TopoDS_Shape aSubShape)
 {
-  //MESSAGE("SMESH_subMesh::InsertDependence");
   SMESH_subMesh *aSubMesh = _father->GetSubMesh(aSubShape);
-  int type = aSubShape.ShapeType();
-  int ordType = 9 - type;               // 2 = Vertex, 8 = CompSolid
-  int cle = aSubMesh->GetId();
-  cle += 10000000 * ordType;    // sort map by ordType then index
+  int cle = dependsOnMapKey( aSubMesh );
   if ( _mapDepend.find( cle ) == _mapDepend.end())
   {
     _mapDepend[cle] = aSubMesh;
@@ -487,19 +578,28 @@ void SMESH_subMesh::InsertDependence(const TopoDS_Shape aSubShape)
   }
 }
 
+//================================================================================
+/*!
+ * \brief Return \c true if \a this sub-mesh depends on \a other
+ */
+//================================================================================
+
+bool SMESH_subMesh::DependsOn( const SMESH_subMesh* other ) const
+{
+  return other ? _mapDepend.count( dependsOnMapKey( other )) : false;
+}
+
 //=============================================================================
 /*!
- *
+ * Return a shape of \a this sub-mesh
  */
 //=============================================================================
 
 const TopoDS_Shape & SMESH_subMesh::GetSubShape() const
 {
-       //MESSAGE("SMESH_subMesh::GetSubShape");
-       return _subShape;
+  return _subShape;
 }
 
-
 //=======================================================================
 //function : CanAddHypothesis
 //purpose  : return true if theHypothesis can be attached to me:
@@ -510,12 +610,13 @@ bool SMESH_subMesh::CanAddHypothesis(const SMESH_Hypothesis* theHypothesis) cons
 {
   int aHypDim   = theHypothesis->GetDim();
   int aShapeDim = SMESH_Gen::GetShapeDim(_subShape);
-  if (aHypDim == 3 && aShapeDim == 3) {
-    // check case of open shell
-    //if (_subShape.ShapeType() == TopAbs_SHELL && !_subShape.Closed())
-    if (_subShape.ShapeType() == TopAbs_SHELL && !BRep_Tool::IsClosed(_subShape))
-      return false;
-  }
+  // issue 21106. Forbid 3D mesh on the SHELL
+  // if (aHypDim == 3 && aShapeDim == 3) {
+  //   // check case of open shell
+  //   //if (_subShape.ShapeType() == TopAbs_SHELL && !_subShape.Closed())
+  //   if (_subShape.ShapeType() == TopAbs_SHELL && !BRep_Tool::IsClosed(_subShape))
+  //     return false;
+  // }
   if ( aHypDim <= aShapeDim )
     return true;
 
@@ -531,8 +632,14 @@ bool SMESH_subMesh::IsApplicableHypotesis(const SMESH_Hypothesis* theHypothesis,
                                           const TopAbs_ShapeEnum  theShapeType)
 {
   if ( theHypothesis->GetType() > SMESHDS_Hypothesis::PARAM_ALGO)
+  {
     // algorithm
-    return ( theHypothesis->GetShapeType() & (1<< theShapeType));
+    if ( theHypothesis->GetShapeType() & (1<< theShapeType))
+      // issue 21106. Forbid 3D mesh on the SHELL
+      return !( theHypothesis->GetDim() == 3 && theShapeType == TopAbs_SHELL );
+    else
+      return false;
+  }
 
   // hypothesis
   switch ( theShapeType ) {
@@ -568,10 +675,6 @@ bool SMESH_subMesh::IsApplicableHypotesis(const SMESH_Hypothesis* theHypothesis,
 SMESH_Hypothesis::Hypothesis_Status
   SMESH_subMesh::AlgoStateEngine(int event, SMESH_Hypothesis * anHyp)
 {
-  //  MESSAGE("SMESH_subMesh::AlgoStateEngine");
-  //SCRUTE(_algoState);
-  //SCRUTE(event);
-
   // **** les retour des evenement shape sont significatifs
   // (add ou remove fait ou non)
   // le retour des evenement father n'indiquent pas que add ou remove fait
@@ -579,8 +682,8 @@ SMESH_Hypothesis::Hypothesis_Status
   SMESH_Hypothesis::Hypothesis_Status aux_ret, ret = SMESH_Hypothesis::HYP_OK;
 
   SMESHDS_Mesh* meshDS =_father->GetMeshDS();
-  SMESH_Gen*    gen    =_father->GetGen();
   SMESH_Algo*   algo   = 0;
+  _algo = 0;
 
   if (_subShape.ShapeType() == TopAbs_VERTEX )
   {
@@ -596,7 +699,7 @@ SMESH_Hypothesis::Hypothesis_Status
       if ( event != REMOVE_FATHER_ALGO )
       {
         _algoState = NO_ALGO;
-        algo = gen->GetAlgo(*_father, _subShape);
+        algo = GetAlgo();
         if ( algo ) {
           _algoState = MISSING_HYP;
           if ( event == REMOVE_FATHER_HYP ||
@@ -609,6 +712,7 @@ SMESH_Hypothesis::Hypothesis_Status
 
   int oldAlgoState = _algoState;
   bool modifiedHyp = (event == MODIF_HYP);  // if set to true, force event MODIF_ALGO_STATE
+  SMESH_Algo* algoRequiringCleaning = 0;
 
   bool isApplicableHyp = IsApplicableHypotesis( anHyp );
 
@@ -625,6 +729,16 @@ SMESH_Hypothesis::Hypothesis_Status
     // ----------------------
     if (isApplicableHyp && !_father->IsNotConformAllowed() && !IsConform( algo ))
       return SMESH_Hypothesis::HYP_NOTCONFORM;
+
+    // check if all-dimensional algo is hidden by other local one
+    if ( event == ADD_ALGO ) {
+      SMESH_HypoFilter filter( SMESH_HypoFilter::HasType( algo->GetType() ));
+      filter.Or( SMESH_HypoFilter::HasType( algo->GetType()+1 ));
+      filter.Or( SMESH_HypoFilter::HasType( algo->GetType()+2 ));
+      if ( SMESH_Algo * curAlgo = (SMESH_Algo*)_father->GetHypothesis(_subShape, filter, true ))
+        if ( !curAlgo->NeedDiscreteBoundary() )
+          algoRequiringCleaning = curAlgo;
+    }
   }
 
   // ----------------------------------
@@ -635,7 +749,7 @@ SMESH_Hypothesis::Hypothesis_Status
     if ( ! CanAddHypothesis( anHyp )) // check dimension
       return SMESH_Hypothesis::HYP_BAD_DIM;
 
-    if ( /*!anHyp->IsAuxiliary() &&*/ GetSimilarAttached( _subShape, anHyp ) )
+    if ( /*!anHyp->IsAuxiliary() &&*/ getSimilarAttached( _subShape, anHyp ) )
       return SMESH_Hypothesis::HYP_ALREADY_EXIST;
 
     if ( !meshDS->AddHypothesis(_subShape, anHyp))
@@ -653,16 +767,8 @@ SMESH_Hypothesis::Hypothesis_Status
     if (event == REMOVE_ALGO)
     {
       algo = dynamic_cast<SMESH_Algo*> (anHyp);
-      if (!algo->NeedDescretBoundary())
-      {
-        // clean all mesh in the tree of the current submesh;
-        // we must perform it now because later
-        // we will have no information about the type of the removed algo
-        CleanDependants();
-       ComputeStateEngine( CLEAN );
-        CleanDependsOn();
-        ComputeSubMeshStateEngine( CHECK_COMPUTE_STATE );
-      }
+      if (!algo->NeedDiscreteBoundary())
+        algoRequiringCleaning = algo;
     }
   }
 
@@ -682,16 +788,16 @@ SMESH_Hypothesis::Hypothesis_Status
     case ADD_HYP:
       break;
     case ADD_ALGO: {
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       ASSERT(algo);
       if (algo->CheckHypothesis((*_father),_subShape, aux_ret))
-        SetAlgoState(HYP_OK);
+        setAlgoState(HYP_OK);
       else if ( algo->IsStatusFatal( aux_ret )) {
         meshDS->RemoveHypothesis(_subShape, anHyp);
         ret = aux_ret;
       }
       else
-        SetAlgoState(MISSING_HYP);
+        setAlgoState(MISSING_HYP);
       break;
     }
     case REMOVE_HYP:
@@ -699,26 +805,26 @@ SMESH_Hypothesis::Hypothesis_Status
     case ADD_FATHER_HYP:
       break;
     case ADD_FATHER_ALGO: {    // Algo just added in father
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       ASSERT(algo);
       if ( algo == anHyp ) {
         if ( algo->CheckHypothesis((*_father),_subShape, aux_ret))
-          SetAlgoState(HYP_OK);
+          setAlgoState(HYP_OK);
         else
-          SetAlgoState(MISSING_HYP);
+          setAlgoState(MISSING_HYP);
       }
       break;
     }
     case REMOVE_FATHER_HYP:
       break;
     case REMOVE_FATHER_ALGO: {
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       if (algo)
       {
         if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
-            SetAlgoState(HYP_OK);
+            setAlgoState(HYP_OK);
         else
-          SetAlgoState(MISSING_HYP);
+          setAlgoState(MISSING_HYP);
       }
       break;
     }
@@ -735,10 +841,10 @@ SMESH_Hypothesis::Hypothesis_Status
     switch (event)
     {
     case ADD_HYP: {
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       ASSERT(algo);
       if ( algo->CheckHypothesis((*_father),_subShape, ret ))
-        SetAlgoState(HYP_OK);
+        setAlgoState(HYP_OK);
       if (SMESH_Hypothesis::IsStatusFatal( ret ))
         meshDS->RemoveHypothesis(_subShape, anHyp);
       else if (!_father->IsUsedHypothesis( anHyp, this ))
@@ -749,70 +855,70 @@ SMESH_Hypothesis::Hypothesis_Status
       break;
     }
     case ADD_ALGO: {           //already existing algo : on father ?
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       ASSERT(algo);
       if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))// ignore hyp status
-        SetAlgoState(HYP_OK);
+        setAlgoState(HYP_OK);
       else if ( algo->IsStatusFatal( aux_ret )) {
         meshDS->RemoveHypothesis(_subShape, anHyp);
         ret = aux_ret;
       }
       else
-        SetAlgoState(MISSING_HYP);
+        setAlgoState(MISSING_HYP);
       break;
     }
     case REMOVE_HYP:
       break;
     case REMOVE_ALGO: {        // perhaps a father algo applies ?
-      algo = gen->GetAlgo((*_father), _subShape);
-      if (algo == NULL)  // no more algo applying on subShape...
+      algo = GetAlgo();
+      if (algo == NULL)  // no more algo applying on sub-shape...
       {
-        SetAlgoState(NO_ALGO);
+        setAlgoState(NO_ALGO);
       }
       else
       {
         if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
-          SetAlgoState(HYP_OK);
+          setAlgoState(HYP_OK);
         else
-          SetAlgoState(MISSING_HYP);
+          setAlgoState(MISSING_HYP);
       }
       break;
     }
     case MODIF_HYP: // assigned hypothesis value may become good
     case ADD_FATHER_HYP: {
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       ASSERT(algo);
       if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
-        SetAlgoState(HYP_OK);
+        setAlgoState(HYP_OK);
       else
-        SetAlgoState(MISSING_HYP);
+        setAlgoState(MISSING_HYP);
       break;
     }
     case ADD_FATHER_ALGO: { // new father algo
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       ASSERT( algo );
       if ( algo == anHyp ) {
         if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
-          SetAlgoState(HYP_OK);
+          setAlgoState(HYP_OK);
         else
-          SetAlgoState(MISSING_HYP);
+          setAlgoState(MISSING_HYP);
       }
       break;
     }
     case REMOVE_FATHER_HYP:    // nothing to do
       break;
     case REMOVE_FATHER_ALGO: {
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       if (algo == NULL)  // no more applying algo on father
       {
-        SetAlgoState(NO_ALGO);
+        setAlgoState(NO_ALGO);
       }
       else
       {
         if ( algo->CheckHypothesis((*_father),_subShape , aux_ret ))
-          SetAlgoState(HYP_OK);
+          setAlgoState(HYP_OK);
         else
-          SetAlgoState(MISSING_HYP);
+          setAlgoState(MISSING_HYP);
       }
       break;
     }
@@ -828,7 +934,7 @@ SMESH_Hypothesis::Hypothesis_Status
     switch (event)
     {
     case ADD_HYP: {
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       ASSERT(algo);
       if (!algo->CheckHypothesis((*_father),_subShape, ret ))
       {
@@ -851,7 +957,7 @@ SMESH_Hypothesis::Hypothesis_Status
       break;
     }
     case ADD_ALGO: {           //already existing algo : on father ?
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       if ( algo->CheckHypothesis((*_father),_subShape, aux_ret )) {
         // check if algo changes
         SMESH_HypoFilter f;
@@ -864,24 +970,24 @@ SMESH_Hypothesis::Hypothesis_Status
           modifiedHyp = true;
       }
       else
-        SetAlgoState(MISSING_HYP);
+        setAlgoState(MISSING_HYP);
       break;
     }
     case REMOVE_HYP: {
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       ASSERT(algo);
       if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
-        SetAlgoState(HYP_OK);
+        setAlgoState(HYP_OK);
       else
-        SetAlgoState(MISSING_HYP);
+        setAlgoState(MISSING_HYP);
       modifiedHyp = true;
       break;
     }
     case REMOVE_ALGO: {         // perhaps a father algo applies ?
-      algo = gen->GetAlgo((*_father), _subShape);
-      if (algo == NULL)   // no more algo applying on subShape...
+      algo = GetAlgo();
+      if (algo == NULL)   // no more algo applying on sub-shape...
       {
-        SetAlgoState(NO_ALGO);
+        setAlgoState(NO_ALGO);
       }
       else
       {
@@ -891,13 +997,13 @@ SMESH_Hypothesis::Hypothesis_Status
             modifiedHyp = true;
         }
         else
-          SetAlgoState(MISSING_HYP);
+          setAlgoState(MISSING_HYP);
       }
       break;
     }
     case MODIF_HYP: // hypothesis value may become bad
     case ADD_FATHER_HYP: {  // new father hypothesis ?
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       ASSERT(algo);
       if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
       {
@@ -905,11 +1011,11 @@ SMESH_Hypothesis::Hypothesis_Status
           modifiedHyp = true;
       }
       else
-        SetAlgoState(MISSING_HYP);
+        setAlgoState(MISSING_HYP);
       break;
     }
     case ADD_FATHER_ALGO: {
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       if ( algo == anHyp ) { // a new algo on father
         if ( algo->CheckHypothesis((*_father),_subShape, aux_ret )) {
           // check if algo changes
@@ -923,27 +1029,32 @@ SMESH_Hypothesis::Hypothesis_Status
             modifiedHyp = true;
         }
         else
-          SetAlgoState(MISSING_HYP);
+          setAlgoState(MISSING_HYP);
       }
       break;
     }
     case REMOVE_FATHER_HYP: {
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       ASSERT(algo);
       if ( algo->CheckHypothesis((*_father),_subShape, aux_ret )) {
         // is there the same local hyp or maybe a new father algo applied?
-        if ( !GetSimilarAttached( _subShape, anHyp ) )
+        if ( !getSimilarAttached( _subShape, anHyp ) )
           modifiedHyp = true;
       }
       else
-        SetAlgoState(MISSING_HYP);
+        setAlgoState(MISSING_HYP);
       break;
     }
     case REMOVE_FATHER_ALGO: {
-      algo = gen->GetAlgo((*_father), _subShape);
+      // IPAL21346. Edges not removed when Netgen 1d-2d is removed from a SOLID.
+      // CLEAN was not called at event REMOVE_ALGO because the algo is not applicable to SOLID.
+      algo = dynamic_cast<SMESH_Algo*> (anHyp);
+      if (!algo->NeedDiscreteBoundary())
+        algoRequiringCleaning = algo;
+      algo = GetAlgo();
       if (algo == NULL)  // no more applying algo on father
       {
-        SetAlgoState(NO_ALGO);
+        setAlgoState(NO_ALGO);
       }
       else
       {
@@ -953,7 +1064,7 @@ SMESH_Hypothesis::Hypothesis_Status
             modifiedHyp = true;
         }
         else
-          SetAlgoState(MISSING_HYP);
+          setAlgoState(MISSING_HYP);
       }
       break;
     }
@@ -981,16 +1092,19 @@ SMESH_Hypothesis::Hypothesis_Status
     TopTools_ListIteratorOfListOfShape it( _father->GetAncestors( _subShape ));
     for ( ; ( ret == SMESH_Hypothesis::HYP_OK && it.More()); it.Next() ) {
       if ( SMESH_Algo* upperAlgo = gen->GetAlgo( *_father, it.Value() ))
-        if ( !upperAlgo->NeedDescretBoundary() && !upperAlgo->SupportSubmeshes())
+        if ( !upperAlgo->NeedDiscreteBoundary() && !upperAlgo->SupportSubmeshes())
           ret = SMESH_Hypothesis::HYP_HIDDEN_ALGO;
     }
     // is algo hiding?
     if ( ret == SMESH_Hypothesis::HYP_OK &&
-         !algo->NeedDescretBoundary()    &&
+         !algo->NeedDiscreteBoundary()    &&
          !algo->SupportSubmeshes()) {
+      TopoDS_Shape algoAssignedTo, otherAssignedTo;
+      gen->GetAlgo( *_father, _subShape, &algoAssignedTo );
       map<int, SMESH_subMesh*>::reverse_iterator i_sm = _mapDepend.rbegin();
       for ( ; ( ret == SMESH_Hypothesis::HYP_OK && i_sm != _mapDepend.rend()) ; ++i_sm )
-        if ( gen->GetAlgo( *_father, i_sm->second->_subShape ))
+        if ( gen->GetAlgo( *_father, i_sm->second->_subShape, &otherAssignedTo ) &&
+             SMESH_MesherHelper::IsSubShape( /*sub=*/otherAssignedTo, /*main=*/algoAssignedTo ))
           ret = SMESH_Hypothesis::HYP_HIDING_ALGO;
     }
   }
@@ -1000,10 +1114,13 @@ SMESH_Hypothesis::Hypothesis_Status
   if ( stateChange && _algoState == HYP_OK ) // hyp becomes OK
     algo->SetEventListener( this );
 
-  NotifyListenersOnEvent( event, ALGO_EVENT, anHyp );
+  if ( event == REMOVE_ALGO || event == REMOVE_FATHER_ALGO )
+    _algo = 0;
+
+  notifyListenersOnEvent( event, ALGO_EVENT, anHyp );
 
   if ( stateChange && oldAlgoState == HYP_OK ) { // hyp becomes KO
-    DeleteOwnListeners();
+    deleteOwnListeners();
     SetIsAlwaysComputed( false );
     if (_subShape.ShapeType() == TopAbs_VERTEX ) {
       // restore default states
@@ -1012,9 +1129,18 @@ SMESH_Hypothesis::Hypothesis_Status
     }
   }
 
+  if ( algoRequiringCleaning ) {
+    // added or removed algo is all-dimensional
+    ComputeStateEngine( CLEAN );
+    cleanDependsOn( algoRequiringCleaning );
+    ComputeSubMeshStateEngine( CHECK_COMPUTE_STATE );
+  }
+
   if (stateChange || modifiedHyp)
     ComputeStateEngine(MODIF_ALGO_STATE);
 
+  _realComputeCost = ( _algoState == HYP_OK ) ? computeCost() : 0;
+
   return ret;
 }
 
@@ -1031,9 +1157,9 @@ bool SMESH_subMesh::IsConform(const SMESH_Algo* theAlgo)
   // Suppose that theAlgo is applicable to _subShape, do not check it here
   //if ( !IsApplicableHypotesis( theAlgo )) return false;
 
-  // check only algo that doesn't NeedDescretBoundary(): because mesh made
+  // check only algo that doesn't NeedDiscreteBoundary(): because mesh made
   // on a sub-shape will be ignored by theAlgo
-  if ( theAlgo->NeedDescretBoundary() ||
+  if ( theAlgo->NeedDiscreteBoundary() ||
        !theAlgo->OnlyUnaryInput() ) // all adjacent shapes will be meshed by this algo?
     return true;
 
@@ -1062,7 +1188,7 @@ bool SMESH_subMesh::IsConform(const SMESH_Algo* theAlgo)
       // check algo attached to smAdjacent
       SMESH_Algo * algo = gen->GetAlgo((*_father), adjacent);
       if (algo &&
-          !algo->NeedDescretBoundary() &&
+          !algo->NeedDiscreteBoundary() &&
           algo->OnlyUnaryInput())
         return false; // NOT CONFORM MESH WILL BE PRODUCED
     }
@@ -1077,7 +1203,7 @@ bool SMESH_subMesh::IsConform(const SMESH_Algo* theAlgo)
  */
 //=============================================================================
 
-void SMESH_subMesh::SetAlgoState(int state)
+void SMESH_subMesh::setAlgoState(algo_state state)
 {
   _algoState = state;
 }
@@ -1107,17 +1233,81 @@ SMESH_Hypothesis::Hypothesis_Status
   return ret;
 }
 
-//=============================================================================
+//================================================================================
 /*!
- *
+ * \brief Remove elements from sub-meshes.
+ *  \param algoRequiringCleaning - an all-dimensional algorithm whose presence
+ *         causes the cleaning.
  */
-//=============================================================================
+//================================================================================
 
-void SMESH_subMesh::CleanDependsOn()
+void SMESH_subMesh::cleanDependsOn( SMESH_Algo* algoRequiringCleaning/*=0*/ )
 {
-  SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,false);
-  while ( smIt->more() )
-    smIt->next()->ComputeStateEngine(CLEAN);
+  SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,
+                                                       /*complexShapeFirst=*/true);
+  if ( _father->NbNodes() == 0 )
+  {
+    while ( smIt->more() )
+      smIt->next()->ComputeStateEngine(CHECK_COMPUTE_STATE);
+  }
+  else if ( !algoRequiringCleaning || !algoRequiringCleaning->SupportSubmeshes() )
+  {
+    while ( smIt->more() )
+      smIt->next()->ComputeStateEngine(CLEAN);
+  }
+  else if ( algoRequiringCleaning && algoRequiringCleaning->SupportSubmeshes() )
+  {
+    SMESHDS_Mesh* meshDS = _father->GetMeshDS();
+
+    // find sub-meshes to keep elements on
+    set< SMESH_subMesh* > smToKeep;
+    TopAbs_ShapeEnum prevShapeType = TopAbs_SHAPE;
+    bool toKeepPrevShapeType = false;
+    while ( smIt->more() )
+    {
+      SMESH_subMesh* sm = smIt->next();
+      sm->ComputeStateEngine(CHECK_COMPUTE_STATE);
+      if ( !sm->IsEmpty() )
+      {
+        const bool sameShapeType = ( prevShapeType == sm->GetSubShape().ShapeType() );
+        bool keepSubMeshes = ( sameShapeType && toKeepPrevShapeType );
+        if ( !sameShapeType )
+        {
+          // check if the algo allows presence of global algos of dimension the algo
+          // can generate it-self
+          int  shapeDim = SMESH_Gen::GetShapeDim( sm->GetSubShape() );
+          keepSubMeshes = algoRequiringCleaning->NeedLowerHyps( shapeDim );
+          prevShapeType = sm->GetSubShape().ShapeType();
+          toKeepPrevShapeType = keepSubMeshes;
+        }
+        if ( !keepSubMeshes )
+        {
+          // look for an algo assigned to sm
+          bool algoFound = false;
+          const list<const SMESHDS_Hypothesis*>& hyps = meshDS->GetHypothesis( sm->_subShape );
+          list<const SMESHDS_Hypothesis*>::const_iterator h = hyps.begin();
+          for ( ; ( !algoFound && h != hyps.end() ); ++h )
+            algoFound = ((*h)->GetType() != SMESHDS_Hypothesis::PARAM_ALGO );
+          keepSubMeshes = algoFound;
+        }
+        // remember all sub-meshes of sm
+        if ( keepSubMeshes )
+        {
+          SMESH_subMeshIteratorPtr smIt2 = getDependsOnIterator(false,true);
+          while ( smIt2->more() )
+            smToKeep.insert( smIt2->next() );
+        }
+      }
+    }
+    // remove elements
+    SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,true);
+    while ( smIt->more() )
+    {
+      SMESH_subMesh* sm = smIt->next();
+      if ( !smToKeep.count( sm ))
+        sm->ComputeStateEngine(CLEAN);
+    }
+  }
 }
 
 //=============================================================================
@@ -1128,48 +1318,48 @@ void SMESH_subMesh::CleanDependsOn()
 
 void SMESH_subMesh::DumpAlgoState(bool isMain)
 {
-       int dim = SMESH_Gen::GetShapeDim(_subShape);
-//   if (dim < 1) return;
-       if (isMain)
-       {
-               const map < int, SMESH_subMesh * >&subMeshes = DependsOn();
-
-               map < int, SMESH_subMesh * >::const_iterator itsub;
-               for (itsub = subMeshes.begin(); itsub != subMeshes.end(); itsub++)
-               {
-                       SMESH_subMesh *sm = (*itsub).second;
-                       sm->DumpAlgoState(false);
-               }
-       }
-       int type = _subShape.ShapeType();
-       MESSAGE("dim = " << dim << " type of shape " << type);
-       switch (_algoState)
-       {
-       case NO_ALGO:
-               MESSAGE(" AlgoState = NO_ALGO");
-               break;
-       case MISSING_HYP:
-               MESSAGE(" AlgoState = MISSING_HYP");
-               break;
-       case HYP_OK:
-               MESSAGE(" AlgoState = HYP_OK");
-               break;
-       }
-       switch (_computeState)
-       {
-       case NOT_READY:
-               MESSAGE(" ComputeState = NOT_READY");
-               break;
-       case READY_TO_COMPUTE:
-               MESSAGE(" ComputeState = READY_TO_COMPUTE");
-               break;
-       case COMPUTE_OK:
-               MESSAGE(" ComputeState = COMPUTE_OK");
-               break;
-       case FAILED_TO_COMPUTE:
-               MESSAGE(" ComputeState = FAILED_TO_COMPUTE");
-               break;
-       }
+  // if (dim < 1) return;
+        if (isMain)
+        {
+                const map < int, SMESH_subMesh * >&subMeshes = DependsOn();
+
+                map < int, SMESH_subMesh * >::const_iterator itsub;
+                for (itsub = subMeshes.begin(); itsub != subMeshes.end(); itsub++)
+                {
+                        SMESH_subMesh *sm = (*itsub).second;
+                        sm->DumpAlgoState(false);
+                }
+        }
+        //int type = _subShape.ShapeType();
+        MESSAGE("dim = " << SMESH_Gen::GetShapeDim(_subShape) <<
+                " type of shape " << _subShape.ShapeType());
+        switch (_algoState)
+        {
+        case NO_ALGO:
+                MESSAGE(" AlgoState = NO_ALGO");
+                break;
+        case MISSING_HYP:
+                MESSAGE(" AlgoState = MISSING_HYP");
+                break;
+        case HYP_OK:
+                MESSAGE(" AlgoState = HYP_OK");
+                break;
+        }
+        switch (_computeState)
+        {
+        case NOT_READY:
+                MESSAGE(" ComputeState = NOT_READY");
+                break;
+        case READY_TO_COMPUTE:
+                MESSAGE(" ComputeState = READY_TO_COMPUTE");
+                break;
+        case COMPUTE_OK:
+                MESSAGE(" ComputeState = COMPUTE_OK");
+                break;
+        case FAILED_TO_COMPUTE:
+                MESSAGE(" ComputeState = FAILED_TO_COMPUTE");
+                break;
+        }
 }
 
 //================================================================================
@@ -1189,7 +1379,7 @@ static void cleanSubMesh( SMESH_subMesh * subMesh )
         const SMDS_MeshElement * elt = ite->next();
         //MESSAGE( " RM elt: "<<elt->GetID()<<" ( "<<elt->NbNodes()<<" )" );
         //meshDS->RemoveElement(elt);
-        meshDS->RemoveFreeElement(elt, subMeshDS);
+        meshDS->RemoveFreeElement(elt, 0);
       }
 
       SMDS_NodeIteratorPtr itn = subMeshDS->GetNodes();
@@ -1197,10 +1387,11 @@ static void cleanSubMesh( SMESH_subMesh * subMesh )
         const SMDS_MeshNode * node = itn->next();
         //MESSAGE( " RM node: "<<node->GetID());
         if ( node->NbInverseElements() == 0 )
-          meshDS->RemoveFreeNode(node, subMeshDS);
+          meshDS->RemoveFreeNode(node, 0);
         else // for StdMeshers_CompositeSegment_1D: node in one submesh, edge in another
           meshDS->RemoveNode(node);
       }
+      subMeshDS->Clear();
     }
   }
 }
@@ -1213,25 +1404,40 @@ static void cleanSubMesh( SMESH_subMesh * subMesh )
 
 bool SMESH_subMesh::ComputeStateEngine(int event)
 {
-  _computeError.reset();
+  switch ( event ) {
+  case MODIF_ALGO_STATE:
+  case COMPUTE:
+  case COMPUTE_SUBMESH:
+    //case COMPUTE_CANCELED:
+  case CLEAN:
+    //case SUBMESH_COMPUTED:
+    //case SUBMESH_RESTORED:
+    //case SUBMESH_LOADED:
+    //case MESH_ENTITY_REMOVED:
+    //case CHECK_COMPUTE_STATE:
+    _computeError.reset(); break;
+  default:;
+  }
 
-  //MESSAGE("SMESH_subMesh::ComputeStateEngine");
-  //SCRUTE(_computeState);
-  //SCRUTE(event);
+  if ( event == CLEAN )
+    _alwaysComputed = false; // Unset 'true' set by MergeNodes() (issue 0022182)
 
   if (_subShape.ShapeType() == TopAbs_VERTEX)
   {
     _computeState = READY_TO_COMPUTE;
     SMESHDS_SubMesh* smDS = GetSubMeshDS();
-    if ( smDS && smDS->NbNodes() ) {
+    if ( smDS && smDS->NbNodes() )
+    {
       if ( event == CLEAN ) {
-        CleanDependants();
+        cleanDependants();
         cleanSubMesh( this );
       }
       else
         _computeState = COMPUTE_OK;
     }
-    else if ( event == COMPUTE && !_alwaysComputed ) {
+    else if (( event == COMPUTE || event == COMPUTE_SUBMESH )
+             && !_alwaysComputed )
+    {
       const TopoDS_Vertex & V = TopoDS::Vertex( _subShape );
       gp_Pnt P = BRep_Tool::Pnt(V);
       if ( SMDS_MeshNode * n = _father->GetMeshDS()->AddNode(P.X(), P.Y(), P.Z()) ) {
@@ -1240,7 +1446,7 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
       }
     }
     if ( event == MODIF_ALGO_STATE )
-      CleanDependants();
+      cleanDependants();
     return true;
   }
   SMESH_Gen *gen = _father->GetGen();
@@ -1258,25 +1464,32 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
     switch (event)
     {
     case MODIF_ALGO_STATE:
-      algo = gen->GetAlgo((*_father), _subShape);
-      if (algo && !algo->NeedDescretBoundary())
-        CleanDependsOn(); // clean sub-meshes with event CLEAN
+      algo = GetAlgo();
+      if (algo && !algo->NeedDiscreteBoundary())
+        cleanDependsOn( algo ); // clean sub-meshes with event CLEAN
       if ( _algoState == HYP_OK )
         _computeState = READY_TO_COMPUTE;
       break;
-    case COMPUTE:              // nothing to do
+    case COMPUTE:               // nothing to do
+    case COMPUTE_SUBMESH:
+      break;
+    case COMPUTE_CANCELED:      // nothing to do
       break;
     case CLEAN:
-      CleanDependants();
-      RemoveSubMeshElementsAndNodes();
+      cleanDependants();
+      removeSubMeshElementsAndNodes();
       break;
-    case SUBMESH_COMPUTED:     // nothing to do
+    case SUBMESH_COMPUTED:      // nothing to do
       break;
     case SUBMESH_RESTORED:
       ComputeSubMeshStateEngine( SUBMESH_RESTORED );
       break;
     case MESH_ENTITY_REMOVED:
       break;
+    case SUBMESH_LOADED:
+      loadDependentMeshes();
+      ComputeSubMeshStateEngine( SUBMESH_LOADED );
+      //break;
     case CHECK_COMPUTE_STATE:
       if ( IsMeshComputed() )
         _computeState = COMPUTE_OK;
@@ -1294,60 +1507,75 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
     {
     case MODIF_ALGO_STATE:
       _computeState = NOT_READY;
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       if (algo)
       {
-        if (!algo->NeedDescretBoundary())
-          CleanDependsOn(); // clean sub-meshes with event CLEAN
+        if (!algo->NeedDiscreteBoundary())
+          cleanDependsOn( algo ); // clean sub-meshes with event CLEAN
         if ( _algoState == HYP_OK )
           _computeState = READY_TO_COMPUTE;
       }
       break;
     case COMPUTE:
+    case COMPUTE_SUBMESH:
       {
-        algo = gen->GetAlgo((*_father), _subShape);
+        algo = GetAlgo();
         ASSERT(algo);
         ret = algo->CheckHypothesis((*_father), _subShape, hyp_status);
         if (!ret)
         {
           MESSAGE("***** verify compute state *****");
           _computeState = NOT_READY;
-          SetAlgoState(MISSING_HYP);
+          setAlgoState(MISSING_HYP);
           break;
         }
         TopoDS_Shape shape = _subShape;
+        algo->SubMeshesToCompute().assign( 1, this );
         // check submeshes needed
         if (_father->HasShapeToMesh() ) {
-          bool subComputed = false;
-          if (!algo->OnlyUnaryInput())
-            shape = GetCollection( gen, algo, subComputed );
-          else
+          bool subComputed = false, subFailed = false;
+          if (!algo->OnlyUnaryInput()) {
+            if ( event == COMPUTE /*&&
+                 ( algo->NeedDiscreteBoundary() || algo->SupportSubmeshes() )*/)
+              shape = getCollection( gen, algo, subComputed, subFailed, algo->SubMeshesToCompute());
+            else
+              subComputed = SubMeshesComputed( & subFailed );
+          }
+          else {
             subComputed = SubMeshesComputed();
-          ret = ( algo->NeedDescretBoundary() ? subComputed :
-                  algo->SupportSubmeshes() ? true :
+          }
+          ret = ( algo->NeedDiscreteBoundary() ? subComputed :
+                  algo->SupportSubmeshes() ? !subFailed :
                   ( !subComputed || _father->IsNotConformAllowed() ));
-          if (!ret) {
+          if (!ret)
+          {
             _computeState = FAILED_TO_COMPUTE;
-            if ( !algo->NeedDescretBoundary() )
+            if ( !algo->NeedDiscreteBoundary() && !subFailed )
               _computeError =
                 SMESH_ComputeError::New(COMPERR_BAD_INPUT_MESH,
-                                        "Unexpected computed submesh",algo);
-            break;
+                                        "Unexpected computed sub-mesh",algo);
+            break; // goto exit
           }
         }
-        // compute
-//         CleanDependants(); for "UseExisting_*D" algos
-//         RemoveSubMeshElementsAndNodes();
+        // Compute
+
+        // to restore cout that may be redirected by algo
+        std::streambuf* coutBuffer = std::cout.rdbuf();
+
+        //cleanDependants(); for "UseExisting_*D" algos
+        //removeSubMeshElementsAndNodes();
+        loadDependentMeshes();
         ret = false;
         _computeState = FAILED_TO_COMPUTE;
         _computeError = SMESH_ComputeError::New(COMPERR_OK,"",algo);
         try {
-#if (OCC_VERSION_MAJOR << 16 | OCC_VERSION_MINOR << 8 | OCC_VERSION_MAINTENANCE) > 0x060100
           OCC_CATCH_SIGNALS;
-#endif
+
           algo->InitComputeError();
+
           MemoryReserve aMemoryReserve;
           SMDS_Mesh::CheckMemory();
+          Kernel_Utils::Localizer loc;
           if ( !_father->HasShapeToMesh() ) // no shape
           {
             SMESH_MesherHelper helper( *_father );
@@ -1359,8 +1587,13 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
           {
             ret = algo->Compute((*_father), shape);
           }
-          if ( !_computeError || ( !ret && _computeError->IsOK() ) ) // algo can set _computeError of submesh
-            _computeError = algo->GetComputeError();
+          // algo can set _computeError of submesh
+          _computeError = SMESH_ComputeError::Worst( _computeError, algo->GetComputeError() );
+        }
+        catch ( ::SMESH_ComputeError& comperr ) {
+          cout << " SMESH_ComputeError caught" << endl;
+          if ( !_computeError ) _computeError = SMESH_ComputeError::New();
+          *_computeError = comperr;
         }
         catch ( std::bad_alloc& exc ) {
           MESSAGE("std::bad_alloc thrown inside algo->Compute()");
@@ -1390,9 +1623,12 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
           }
         }
         catch ( SALOME_Exception& S_ex ) {
+          const int skipSalomeShift = 7; /* to skip "Salome " of
+                                            "Salome Exception" prefix returned
+                                            by SALOME_Exception::what() */
           if ( !_computeError ) _computeError = SMESH_ComputeError::New();
           _computeError->myName    = COMPERR_SLM_EXCEPTION;
-          _computeError->myComment = S_ex.what();
+          _computeError->myComment = S_ex.what() + skipSalomeShift;
         }
         catch ( std::exception& exc ) {
           if ( !_computeError ) _computeError = SMESH_ComputeError::New();
@@ -1405,38 +1641,79 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
           else
             ret = false;
         }
-        if (ret && !_alwaysComputed && shape == _subShape) { // check if anything was built
-          ret = ( GetSubMeshDS() && ( GetSubMeshDS()->NbElements() || GetSubMeshDS()->NbNodes() ));
+        std::cout.rdbuf( coutBuffer ); // restore cout that could be redirected by algo
+
+        // check if an error reported on any sub-shape
+        bool isComputeErrorSet = !checkComputeError( algo, ret, shape );
+        if ( isComputeErrorSet )
+          ret = false;
+        // check if anything was built
+        TopExp_Explorer subS(shape, _subShape.ShapeType());
+        if (ret)
+        {
+          for (; ret && subS.More(); subS.Next())
+            if ( !_father->GetSubMesh( subS.Current() )->IsMeshComputed() &&
+                 ( _subShape.ShapeType() != TopAbs_EDGE ||
+                   !algo->isDegenerated( TopoDS::Edge( subS.Current() ))))
+              ret = false;
         }
-        bool isComputeErrorSet = !CheckComputeError( algo, shape );
+        // Set _computeError
         if (!ret && !isComputeErrorSet)
         {
-          // Set _computeError
-          if ( !_computeError )
-            _computeError = SMESH_ComputeError::New();
-          if ( _computeError->IsOK() )
-            _computeError->myName = COMPERR_ALGO_FAILED;
-          _computeState = FAILED_TO_COMPUTE;
+          for (subS.ReInit(); subS.More(); subS.Next())
+          {
+            SMESH_subMesh* sm = _father->GetSubMesh( subS.Current() );
+            if ( !sm->IsMeshComputed() )
+            {
+              if ( !sm->_computeError )
+                sm->_computeError = SMESH_ComputeError::New();
+              if ( sm->_computeError->IsOK() )
+                sm->_computeError->myName = COMPERR_ALGO_FAILED;
+              sm->_computeState = FAILED_TO_COMPUTE;
+              sm->_computeError->myAlgo = algo;
+            }
+          }
         }
-        if (ret)
+        if (ret && _computeError && _computeError->myName != COMPERR_WARNING )
         {
           _computeError.reset();
         }
-        UpdateDependantsState( SUBMESH_COMPUTED ); // send event SUBMESH_COMPUTED
+
+        // send event SUBMESH_COMPUTED
+        if ( ret ) {
+          if ( !algo->NeedDiscreteBoundary() )
+            // send SUBMESH_COMPUTED to dependants of all sub-meshes of shape
+            for (subS.ReInit(); subS.More(); subS.Next())
+            {
+              SMESH_subMesh* sm = _father->GetSubMesh( subS.Current() );
+              SMESH_subMeshIteratorPtr smIt = sm->getDependsOnIterator(false,false);
+              while ( smIt->more() ) {
+                sm = smIt->next();
+                if ( sm->GetSubShape().ShapeType() == TopAbs_VERTEX )
+                  sm->updateDependantsState( SUBMESH_COMPUTED );
+                else
+                  break;
+              }
+            }
+          else
+            updateDependantsState( SUBMESH_COMPUTED );
+        }
       }
       break;
+    case COMPUTE_CANCELED:               // nothing to do
+      break;
     case CLEAN:
-      CleanDependants();
-      RemoveSubMeshElementsAndNodes();
+      cleanDependants();
+      removeSubMeshElementsAndNodes();
       _computeState = NOT_READY;
-      algo = gen->GetAlgo((*_father), _subShape);
+      algo = GetAlgo();
       if (algo)
       {
         ret = algo->CheckHypothesis((*_father), _subShape, hyp_status);
         if (ret)
           _computeState = READY_TO_COMPUTE;
         else
-          SetAlgoState(MISSING_HYP);
+          setAlgoState(MISSING_HYP);
       }
       break;
     case SUBMESH_COMPUTED:      // nothing to do
@@ -1446,11 +1723,15 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
       // happen after retrieval from a file
       ComputeStateEngine( CHECK_COMPUTE_STATE );
       ComputeSubMeshStateEngine( SUBMESH_RESTORED );
-      algo = gen->GetAlgo(*_father, _subShape);
+      algo = GetAlgo();
       if (algo) algo->SubmeshRestored( this );
       break;
     case MESH_ENTITY_REMOVED:
       break;
+    case SUBMESH_LOADED:
+      loadDependentMeshes();
+      ComputeSubMeshStateEngine( SUBMESH_LOADED );
+      //break;
     case CHECK_COMPUTE_STATE:
       if ( IsMeshComputed() )
         _computeState = COMPUTE_OK;
@@ -1468,15 +1749,17 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
     {
     case MODIF_ALGO_STATE:
       ComputeStateEngine( CLEAN );
-      algo = gen->GetAlgo((*_father), _subShape);
-      if (algo && !algo->NeedDescretBoundary())
-        CleanDependsOn(); // clean sub-meshes with event CLEAN
+      algo = GetAlgo();
+      if (algo && !algo->NeedDiscreteBoundary())
+        cleanDependsOn( algo ); // clean sub-meshes with event CLEAN
       break;
     case COMPUTE:               // nothing to do
       break;
+    case COMPUTE_CANCELED:      // nothing to do
+      break;
     case CLEAN:
-      CleanDependants();  // clean sub-meshes, dependant on this one, with event CLEAN
-      RemoveSubMeshElementsAndNodes();
+      cleanDependants();  // clean sub-meshes, dependant on this one, with event CLEAN
+      removeSubMeshElementsAndNodes();
       _computeState = NOT_READY;
       if ( _algoState == HYP_OK )
         _computeState = READY_TO_COMPUTE;
@@ -1486,20 +1769,24 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
     case SUBMESH_RESTORED:
       ComputeStateEngine( CHECK_COMPUTE_STATE );
       ComputeSubMeshStateEngine( SUBMESH_RESTORED );
-      algo = gen->GetAlgo(*_father, _subShape);
+      algo = GetAlgo();
       if (algo) algo->SubmeshRestored( this );
       break;
     case MESH_ENTITY_REMOVED:
-      UpdateDependantsState( CHECK_COMPUTE_STATE );
-      ComputeStateEngine( CHECK_COMPUTE_STATE );
+      updateDependantsState    ( CHECK_COMPUTE_STATE );
+      ComputeStateEngine       ( CHECK_COMPUTE_STATE );
       ComputeSubMeshStateEngine( CHECK_COMPUTE_STATE );
       break;
     case CHECK_COMPUTE_STATE:
-      if ( !IsMeshComputed() )
+      if ( !IsMeshComputed() ) {
         if (_algoState == HYP_OK)
           _computeState = READY_TO_COMPUTE;
         else
           _computeState = NOT_READY;
+      }
+      break;
+    case SUBMESH_LOADED:
+      // already treated event, thanks to which _computeState == COMPUTE_OK
       break;
     default:
       ASSERT(0);
@@ -1513,19 +1800,28 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
     switch (event)
     {
     case MODIF_ALGO_STATE:
-      algo = gen->GetAlgo((*_father), _subShape);
-      if (algo && !algo->NeedDescretBoundary())
-        CleanDependsOn(); // clean sub-meshes with event CLEAN
+      if ( !IsEmpty() )
+        ComputeStateEngine( CLEAN );
+      algo = GetAlgo();
+      if (algo && !algo->NeedDiscreteBoundary())
+        cleanDependsOn( algo ); // clean sub-meshes with event CLEAN
       if (_algoState == HYP_OK)
         _computeState = READY_TO_COMPUTE;
       else
         _computeState = NOT_READY;
       break;
-    case COMPUTE:      // nothing to do
+    case COMPUTE:        // nothing to do
+    case COMPUTE_SUBMESH:
+      break;
+    case COMPUTE_CANCELED:
+      {
+        algo = GetAlgo();
+        algo->CancelCompute();
+      }
       break;
     case CLEAN:
-      CleanDependants(); // submeshes dependent on me should be cleaned as well
-      RemoveSubMeshElementsAndNodes();
+      cleanDependants(); // submeshes dependent on me should be cleaned as well
+      removeSubMeshElementsAndNodes();
       break;
     case SUBMESH_COMPUTED:      // allow retry compute
       if (_algoState == HYP_OK)
@@ -1547,6 +1843,8 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
         else
           _computeState = NOT_READY;
       break;
+    // case SUBMESH_LOADED:
+    //   break;
     default:
       ASSERT(0);
       break;
@@ -1559,11 +1857,68 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
     break;
   }
 
-  NotifyListenersOnEvent( event, COMPUTE_EVENT );
+  notifyListenersOnEvent( event, COMPUTE_EVENT );
+
+  return ret;
+}
+
+
+//=============================================================================
+/*!
+ *
+ */
+//=============================================================================
+
+bool SMESH_subMesh::Evaluate(MapShapeNbElems& aResMap)
+{
+  _computeError.reset();
+
+  bool ret = true;
+
+  if (_subShape.ShapeType() == TopAbs_VERTEX) {
+    vector<int> aVec(SMDSEntity_Last,0);
+    aVec[SMDSEntity_Node] = 1;
+    aResMap.insert(make_pair(this,aVec));
+    return ret;
+  }
+
+  //SMESH_Gen *gen = _father->GetGen();
+  SMESH_Algo *algo = 0;
+  SMESH_Hypothesis::Hypothesis_Status hyp_status;
+
+  algo = GetAlgo();
+  if(algo && !aResMap.count(this) )
+  {
+    ret = algo->CheckHypothesis((*_father), _subShape, hyp_status);
+    if (!ret) return false;
+
+    if (_father->HasShapeToMesh() && algo->NeedDiscreteBoundary())
+    {
+      // check submeshes needed
+      bool subMeshEvaluated = true;
+      int dimToCheck = SMESH_Gen::GetShapeDim( _subShape ) - 1;
+      SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,/*complexShapeFirst=*/true);
+      while ( smIt->more() && subMeshEvaluated )
+      {
+        SMESH_subMesh* sm = smIt->next();
+        int dim = SMESH_Gen::GetShapeDim( sm->GetSubShape() );
+        if (dim < dimToCheck) break; // the rest subMeshes are all of less dimension
+        const vector<int> & nbs = aResMap[ sm ];
+        subMeshEvaluated = (std::accumulate( nbs.begin(), nbs.end(), 0 ) > 0 );
+      }
+      if ( !subMeshEvaluated )
+        return false;
+    }
+    _computeError = SMESH_ComputeError::New(COMPERR_OK,"",algo);
+    ret = algo->Evaluate((*_father), _subShape, aResMap);
+
+    aResMap.insert( make_pair( this,vector<int>(0)));
+  }
 
   return ret;
 }
 
+
 //=======================================================================
 /*!
  * \brief Update compute_state by _computeError and send proper events to
@@ -1572,18 +1927,20 @@ bool SMESH_subMesh::ComputeStateEngine(int event)
  */
 //=======================================================================
 
-bool SMESH_subMesh::CheckComputeError(SMESH_Algo* theAlgo, const TopoDS_Shape& theShape)
+bool SMESH_subMesh::checkComputeError(SMESH_Algo*         theAlgo,
+                                      const bool          theComputeOK,
+                                      const TopoDS_Shape& theShape)
 {
   bool noErrors = true;
 
   if ( !theShape.IsNull() )
   {
     // Check state of submeshes
-    if ( !theAlgo->NeedDescretBoundary())
+    if ( !theAlgo->NeedDiscreteBoundary())
     {
       SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,false);
       while ( smIt->more() )
-        if ( !smIt->next()->CheckComputeError( theAlgo ))
+        if ( !smIt->next()->checkComputeError( theAlgo, theComputeOK ))
           noErrors = false;
     }
 
@@ -1595,27 +1952,39 @@ bool SMESH_subMesh::CheckComputeError(SMESH_Algo* theAlgo, const TopoDS_Shape& t
       for (TopoDS_Iterator subIt( theShape ); subIt.More(); subIt.Next()) {
         SMESH_subMesh* sm = _father->GetSubMesh( subIt.Value() );
         if ( sm != this ) {
-          if ( !sm->CheckComputeError( theAlgo, sm->GetSubShape() ))
+          if ( !sm->checkComputeError( theAlgo, theComputeOK, sm->GetSubShape() ))
             noErrors = false;
-          UpdateDependantsState( SUBMESH_COMPUTED ); // send event SUBMESH_COMPUTED
+          updateDependantsState( SUBMESH_COMPUTED ); // send event SUBMESH_COMPUTED
         }
       }
     }
   }
   {
-    // Check my state
+
+    // Set my _computeState
+
     if ( !_computeError || _computeError->IsOK() )
     {
-      _computeState = COMPUTE_OK;
+      // no error description is set to this sub-mesh, check if any mesh is computed
+      _computeState = IsMeshComputed() ? COMPUTE_OK : FAILED_TO_COMPUTE;
+      if ( _computeState != COMPUTE_OK )
+      {
+        if ( _subShape.ShapeType() == TopAbs_EDGE &&
+             SMESH_Algo::isDegenerated( TopoDS::Edge( _subShape )) )
+          _computeState = COMPUTE_OK;
+        else if ( theComputeOK )
+          _computeError = SMESH_ComputeError::New(COMPERR_NO_MESH_ON_SHAPE,"",theAlgo);
+      }
     }
-    else
+
+    if ( _computeError && !_computeError->IsOK() )
     {
       if ( !_computeError->myAlgo )
         _computeError->myAlgo = theAlgo;
 
       // Show error
       SMESH_Comment text;
-      text << theAlgo->GetName() << " failed on subshape #" << _Id << " with error ";
+      text << theAlgo->GetName() << " failed on sub-shape #" << _Id << " with error ";
       if (_computeError->IsCommon() )
         text << _computeError->CommonName();
       else
@@ -1623,73 +1992,22 @@ bool SMESH_subMesh::CheckComputeError(SMESH_Algo* theAlgo, const TopoDS_Shape& t
       if ( _computeError->myComment.size() > 0 )
         text << " \"" << _computeError->myComment << "\"";
 
-#ifdef _DEBUG_
-      MESSAGE_BEGIN ( text );
-      // Show vertices location of a failed shape
-      TopTools_IndexedMapOfShape vMap;
-      TopExp::MapShapes( _subShape, TopAbs_VERTEX, vMap );
-      MESSAGE_ADD ( "Subshape vertices " << ( vMap.Extent()>10 ? "(first 10):" : ":") );
-      for ( int iv = 1; iv <= vMap.Extent() && iv < 11; ++iv ) {
-        gp_Pnt P( BRep_Tool::Pnt( TopoDS::Vertex( vMap( iv ) )));
-        MESSAGE_ADD ( "#" << _father->GetMeshDS()->ShapeToIndex( vMap( iv )) << " "
-                   << P.X() << " " << P.Y() << " " << P.Z() << " " );
-      }
-#else
       INFOS( text );
-#endif
-      _computeState = FAILED_TO_COMPUTE;
-      noErrors = false;
-    }
-  }
-  return noErrors;
-}
-
-//=======================================================================
-//function : ApplyToCollection
-//purpose  : Apply theAlgo to all subshapes in theCollection
-//=======================================================================
 
-bool SMESH_subMesh::ApplyToCollection (SMESH_Algo*         theAlgo,
-                                       const TopoDS_Shape& theCollection)
-{
-  MESSAGE("SMESH_subMesh::ApplyToCollection");
-  ASSERT ( !theAlgo->NeedDescretBoundary() );
-
-  if ( _computeError )
-    _computeError->myName = COMPERR_OK;
-
-  bool ok = theAlgo->Compute( *_father, theCollection );
+      _computeState = _computeError->IsKO() ? FAILED_TO_COMPUTE : COMPUTE_OK;
 
-  // set _computeState of subshapes
-  TopExp_Explorer anExplorer( theCollection, _subShape.ShapeType() );
-  for ( ; anExplorer.More(); anExplorer.Next() )
-  {
-    if ( SMESH_subMesh* subMesh = _father->GetSubMeshContaining( anExplorer.Current() ))
-    {
-      bool localOK = subMesh->CheckComputeError( theAlgo );
-      if ( !ok && localOK && !subMesh->IsMeshComputed() )
-      {
-        subMesh->_computeError = theAlgo->GetComputeError();
-        if ( subMesh->_computeError->IsOK() )
-          _computeError = SMESH_ComputeError::New(COMPERR_ALGO_FAILED);
-        localOK = CheckComputeError( theAlgo );
-      }
-      if ( localOK )
-        subMesh->UpdateDependantsState( SUBMESH_COMPUTED );
-      subMesh->UpdateSubMeshState( localOK ? COMPUTE_OK : FAILED_TO_COMPUTE );
+      noErrors = false;
     }
   }
-
-  return true;
+  return noErrors;
 }
 
-
 //=======================================================================
-//function : UpdateSubMeshState
+//function : updateSubMeshState
 //purpose  :
 //=======================================================================
 
-void SMESH_subMesh::UpdateSubMeshState(const compute_state theState)
+void SMESH_subMesh::updateSubMeshState(const compute_state theState)
 {
   SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,false);
   while ( smIt->more() )
@@ -1701,28 +2019,25 @@ void SMESH_subMesh::UpdateSubMeshState(const compute_state theState)
 //purpose  :
 //=======================================================================
 
-void SMESH_subMesh::ComputeSubMeshStateEngine(int event)
+void SMESH_subMesh::ComputeSubMeshStateEngine(int event, const bool includeSelf)
 {
-  SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,false);
+  SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(includeSelf,false);
   while ( smIt->more() )
     smIt->next()->ComputeStateEngine(event);
 }
 
 //=======================================================================
-//function : UpdateDependantsState
+//function : updateDependantsState
 //purpose  :
 //=======================================================================
 
-void SMESH_subMesh::UpdateDependantsState(const compute_event theEvent)
+void SMESH_subMesh::updateDependantsState(const compute_event theEvent)
 {
-  //MESSAGE("SMESH_subMesh::UpdateDependantsState");
   TopTools_ListIteratorOfListOfShape it( _father->GetAncestors( _subShape ));
   for (; it.More(); it.Next())
   {
     const TopoDS_Shape& ancestor = it.Value();
-    SMESH_subMesh *aSubMesh =
-      _father->GetSubMeshContaining(ancestor);
-    if (aSubMesh)
+    if ( SMESH_subMesh *aSubMesh = _father->GetSubMeshContaining(ancestor))
       aSubMesh->ComputeStateEngine( theEvent );
   }
 }
@@ -1733,7 +2048,7 @@ void SMESH_subMesh::UpdateDependantsState(const compute_event theEvent)
  */
 //=============================================================================
 
-void SMESH_subMesh::CleanDependants()
+void SMESH_subMesh::cleanDependants()
 {
   int dimToClean = SMESH_Gen::GetShapeDim( _subShape ) + 1;
 
@@ -1746,7 +2061,8 @@ void SMESH_subMesh::CleanDependants()
       // will erase mesh on other shapes in a compound
       if ( ancestor.ShapeType() >= TopAbs_SOLID ) {
         SMESH_subMesh *aSubMesh = _father->GetSubMeshContaining(ancestor);
-        if (aSubMesh)
+        if (aSubMesh &&
+            !aSubMesh->IsEmpty() ) // prevent infinite CLEAN via event lesteners
           aSubMesh->ComputeStateEngine(CLEAN);
       }
     }
@@ -1759,10 +2075,8 @@ void SMESH_subMesh::CleanDependants()
  */
 //=============================================================================
 
-void SMESH_subMesh::RemoveSubMeshElementsAndNodes()
+void SMESH_subMesh::removeSubMeshElementsAndNodes()
 {
-  //SCRUTE(_subShape.ShapeType());
-
   cleanSubMesh( this );
 
   // algo may bind a submesh not to _subShape, eg 3D algo
@@ -1783,18 +2097,18 @@ void SMESH_subMesh::RemoveSubMeshElementsAndNodes()
 }
 
 //=======================================================================
-//function : GetCollection
+//function : getCollection
 //purpose  : return a shape containing all sub-shapes of the MainShape that can be
 //           meshed at once along with _subShape
 //=======================================================================
 
-TopoDS_Shape SMESH_subMesh::GetCollection(SMESH_Gen * theGen,
+TopoDS_Shape SMESH_subMesh::getCollection(SMESH_Gen * theGen,
                                           SMESH_Algo* theAlgo,
-                                          bool &      theSubComputed)
+                                          bool &      theSubComputed,
+                                          bool &      theSubFailed,
+                                          std::vector<SMESH_subMesh*>& theSubs)
 {
-  MESSAGE("SMESH_subMesh::GetCollection");
-
-  theSubComputed = SubMeshesComputed();
+  theSubComputed = SubMeshesComputed( & theSubFailed );
 
   TopoDS_Shape mainShape = _father->GetMeshDS()->ShapeToMesh();
 
@@ -1806,17 +2120,20 @@ TopoDS_Shape SMESH_subMesh::GetCollection(SMESH_Gen * theGen,
     theAlgo->GetUsedHypothesis( *_father, _subShape, ignoreAuxiliaryHyps ); // copy
 
   // put in a compound all shapes with the same hypothesis assigned
-  // and a good ComputState
+  // and a good ComputeState
 
   TopoDS_Compound aCompound;
   BRep_Builder aBuilder;
   aBuilder.MakeCompound( aCompound );
 
+  theSubs.clear();
+
   TopExp_Explorer anExplorer( mainShape, _subShape.ShapeType() );
   for ( ; anExplorer.More(); anExplorer.Next() )
   {
     const TopoDS_Shape& S = anExplorer.Current();
     SMESH_subMesh* subMesh = _father->GetSubMesh( S );
+    theSubs.push_back( subMesh );
     if ( subMesh == this )
     {
       aBuilder.Add( aCompound, S );
@@ -1836,14 +2153,14 @@ TopoDS_Shape SMESH_subMesh::GetCollection(SMESH_Gen * theGen,
 }
 
 //=======================================================================
-//function : GetSimilarAttached
+//function : getSimilarAttached
 //purpose  : return a hypothesis attached to theShape.
 //           If theHyp is provided, similar but not same hypotheses
 //           is returned; else only applicable ones having theHypType
 //           is returned
 //=======================================================================
 
-const SMESH_Hypothesis* SMESH_subMesh::GetSimilarAttached(const TopoDS_Shape&      theShape,
+const SMESH_Hypothesis* SMESH_subMesh::getSimilarAttached(const TopoDS_Shape&      theShape,
                                                           const SMESH_Hypothesis * theHyp,
                                                           const int                theHypType)
 {
@@ -1876,7 +2193,7 @@ SMESH_Hypothesis::Hypothesis_Status
   MESSAGE ("SMESH_subMesh::CheckConcurentHypothesis");
 
   // is there local hypothesis on me?
-  if ( GetSimilarAttached( _subShape, 0, theHypType ) )
+  if ( getSimilarAttached( _subShape, 0, theHypType ) )
     return SMESH_Hypothesis::HYP_OK;
 
 
@@ -1886,7 +2203,7 @@ SMESH_Hypothesis::Hypothesis_Status
   for (; it.More(); it.Next())
   {
     const TopoDS_Shape& ancestor = it.Value();
-    const SMESH_Hypothesis* hyp = GetSimilarAttached( ancestor, 0, theHypType );
+    const SMESH_Hypothesis* hyp = getSimilarAttached( ancestor, 0, theHypType );
     if ( hyp )
     {
       if ( aPrevWithHyp.IsNull() || aPrevWithHyp.IsSame( ancestor ))
@@ -1903,14 +2220,26 @@ SMESH_Hypothesis::Hypothesis_Status
   return SMESH_Hypothesis::HYP_OK;
 }
 
+//================================================================================
+/*!
+ * \brief Constructor of OwnListenerData
+ */
+//================================================================================
+
+SMESH_subMesh::OwnListenerData::OwnListenerData( SMESH_subMesh* sm, EventListener* el):
+  mySubMesh( sm ),
+  myMeshID( sm ? sm->GetFather()->GetId() : -1 ),
+  mySubMeshID( sm ? sm->GetId() : -1 ),
+  myListener( el )
+{
+}
+
 //================================================================================
 /*!
  * \brief Sets an event listener and its data to a submesh
  * \param listener - the listener to store
  * \param data - the listener data to store
  * \param where - the submesh to store the listener and it's data
- * \param deleteListener - if true then the listener will be deleted as
- *        it is removed from where submesh
  * 
  * It remembers the submesh where it puts the listener in order to delete
  * them when HYP_OK algo_state is lost
@@ -1923,8 +2252,8 @@ void SMESH_subMesh::SetEventListener(EventListener*     listener,
                                      SMESH_subMesh*     where)
 {
   if ( listener && where ) {
-    where->SetEventListener( listener, data );
-    myOwnListeners.push_back( make_pair( where, listener ));
+    where->setEventListener( listener, data );
+    _ownListeners.push_back( OwnListenerData( where, listener ));
   }
 }
 
@@ -1938,34 +2267,95 @@ void SMESH_subMesh::SetEventListener(EventListener*     listener,
  */
 //================================================================================
 
-void SMESH_subMesh::SetEventListener(EventListener* listener, EventListenerData* data)
+void SMESH_subMesh::setEventListener(EventListener*     listener,
+                                     EventListenerData* data)
 {
   map< EventListener*, EventListenerData* >::iterator l_d =
-    myEventListeners.find( listener );
-  if ( l_d != myEventListeners.end() ) {
+    _eventListeners.find( listener );
+  if ( l_d != _eventListeners.end() ) {
     EventListenerData* curData = l_d->second;
     if ( curData && curData != data && curData->IsDeletable() )
       delete curData;
     l_d->second = data;
   }
-  else 
-    myEventListeners.insert( make_pair( listener, data ));
+  else
+  {
+    for ( l_d = _eventListeners.begin(); l_d != _eventListeners.end(); ++l_d )
+      if ( listener->GetName() == l_d->first->GetName() )
+      {
+        EventListenerData* curData = l_d->second;
+        if ( curData && curData != data && curData->IsDeletable() )
+          delete curData;
+        if ( l_d->first != listener && l_d->first->IsDeletable() )
+          delete l_d->first;
+        _eventListeners.erase( l_d );
+        break;
+      }
+    _eventListeners.insert( make_pair( listener, data ));
+  }
 }
 
 //================================================================================
 /*!
  * \brief Return an event listener data
  * \param listener - the listener whose data is
+ * \param myOwn - if \c true, returns a listener set by this sub-mesh,
+ *        else returns a listener listening to events of this sub-mesh
  * \retval EventListenerData* - found data, maybe NULL
  */
 //================================================================================
 
-EventListenerData* SMESH_subMesh::GetEventListenerData(EventListener* listener) const
+EventListenerData* SMESH_subMesh::GetEventListenerData(EventListener* listener,
+                                                       const bool     myOwn) const
 {
-  map< EventListener*, EventListenerData* >::const_iterator l_d =
-    myEventListeners.find( listener );
-  if ( l_d != myEventListeners.end() )
-    return l_d->second;
+  if ( myOwn )
+  {
+    list< OwnListenerData >::const_iterator d;
+    for ( d = _ownListeners.begin(); d != _ownListeners.end(); ++d )
+    {
+      if ( d->myListener == listener && _father->MeshExists( d->myMeshID ))
+        return d->mySubMesh->GetEventListenerData( listener, !myOwn );
+    }
+  }
+  else
+  {
+    map< EventListener*, EventListenerData* >::const_iterator l_d =
+      _eventListeners.find( listener );
+    if ( l_d != _eventListeners.end() )
+      return l_d->second;
+  }
+  return 0;
+}
+
+//================================================================================
+/*!
+ * \brief Return an event listener data
+ * \param listenerName - the listener name
+ * \param myOwn - if \c true, returns a listener set by this sub-mesh,
+ *        else returns a listener listening to events of this sub-mesh
+ * \retval EventListenerData* - found data, maybe NULL
+ */
+//================================================================================
+
+EventListenerData* SMESH_subMesh::GetEventListenerData(const string& listenerName,
+                                                       const bool    myOwn) const
+{
+  if ( myOwn )
+  {
+    list< OwnListenerData >::const_iterator d;
+    for ( d = _ownListeners.begin(); d != _ownListeners.end(); ++d )
+    {
+      if ( _father->MeshExists( d->myMeshID ) && listenerName == d->myListener->GetName())
+        return d->mySubMesh->GetEventListenerData( listenerName, !myOwn );
+    }
+  }
+  else
+  {
+    map< EventListener*, EventListenerData* >::const_iterator l_d = _eventListeners.begin();
+    for ( ; l_d != _eventListeners.end(); ++l_d )
+      if ( listenerName == l_d->first->GetName() )
+        return l_d->second;
+  }
   return 0;
 }
 
@@ -1974,19 +2364,32 @@ EventListenerData* SMESH_subMesh::GetEventListenerData(EventListener* listener)
  * \brief Notify stored event listeners on the occured event
  * \param event - algo_event or compute_event itself
  * \param eventType - algo_event or compute_event
- * \param subMesh - the submesh where the event occures
- * \param data - listener data stored in the subMesh
  * \param hyp - hypothesis, if eventType is algo_event
  */
 //================================================================================
 
-void SMESH_subMesh::NotifyListenersOnEvent( const int         event,
+void SMESH_subMesh::notifyListenersOnEvent( const int         event,
                                             const event_type  eventType,
                                             SMESH_Hypothesis* hyp)
 {
-  map< EventListener*, EventListenerData* >::iterator l_d = myEventListeners.begin();
-  for ( ; l_d != myEventListeners.end(); ++l_d )
-    l_d->first->ProcessEvent( event, eventType, this, l_d->second, hyp );
+  list< pair< EventListener*, EventListenerData* > > eventListeners( _eventListeners.begin(),
+                                                                     _eventListeners.end());
+  list< pair< EventListener*, EventListenerData* > >::iterator l_d = eventListeners.begin();
+  for ( ; l_d != eventListeners.end(); ++l_d )
+  {
+    std::pair< EventListener*, EventListenerData* > li_da = *l_d;
+    if ( !_eventListeners.count( li_da.first )) continue;
+
+    if ( li_da.first->myBusySM.insert( this ).second )
+    {
+      const bool isDeletable = li_da.first->IsDeletable();
+
+      li_da.first->ProcessEvent( event, eventType, this, li_da.second, hyp );
+
+      if ( !isDeletable || _eventListeners.count( li_da.first ))
+        li_da.first->myBusySM.erase( this ); // a listener is hopefully not dead
+    }
+  }
 }
 
 //================================================================================
@@ -1999,11 +2402,20 @@ void SMESH_subMesh::NotifyListenersOnEvent( const int         event,
 void SMESH_subMesh::DeleteEventListener(EventListener* listener)
 {
   map< EventListener*, EventListenerData* >::iterator l_d =
-    myEventListeners.find( listener );
-  if ( l_d != myEventListeners.end() ) {
-    if ( l_d->first  && l_d->first->IsDeletable() )  delete l_d->first;
-    if ( l_d->second && l_d->second->IsDeletable() ) delete l_d->second;
-    myEventListeners.erase( l_d );
+    _eventListeners.find( listener );
+  if ( l_d != _eventListeners.end() && l_d->first )
+  {
+    if ( l_d->second && l_d->second->IsDeletable() )
+    {
+      delete l_d->second;
+    }
+    l_d->first->myBusySM.erase( this );
+    if ( l_d->first->IsDeletable() )
+    {
+      l_d->first->BeforeDelete( this, l_d->second );
+      delete l_d->first;
+    }
+    _eventListeners.erase( l_d );
   }
 }
 
@@ -2013,12 +2425,42 @@ void SMESH_subMesh::DeleteEventListener(EventListener* listener)
  */
 //================================================================================
 
-void SMESH_subMesh::DeleteOwnListeners()
+void SMESH_subMesh::deleteOwnListeners()
+{
+  list< OwnListenerData >::iterator d;
+  for ( d = _ownListeners.begin(); d != _ownListeners.end(); ++d )
+  {
+    if ( !_father->MeshExists( d->myMeshID ))
+      continue;
+    if ( _father->GetId() == d->myMeshID && !_father->GetSubMeshContaining( d->mySubMeshID ))
+      continue;
+    d->mySubMesh->DeleteEventListener( d->myListener );
+  }
+  _ownListeners.clear();
+}
+
+//=======================================================================
+//function : loadDependentMeshes
+//purpose  : loads dependent meshes on SUBMESH_LOADED event
+//=======================================================================
+
+void SMESH_subMesh::loadDependentMeshes()
 {
-  list< pair< SMESH_subMesh*, EventListener* > >::iterator sm_l;
-  for ( sm_l = myOwnListeners.begin(); sm_l != myOwnListeners.end(); ++sm_l)
-    sm_l->first->DeleteEventListener( sm_l->second );
-  myOwnListeners.clear();
+  list< OwnListenerData >::iterator d;
+  for ( d = _ownListeners.begin(); d != _ownListeners.end(); ++d )
+    if ( _father != d->mySubMesh->_father )
+      d->mySubMesh->_father->Load();
+
+  // map< EventListener*, EventListenerData* >::iterator l_d = _eventListeners.begin();
+  // for ( ; l_d != _eventListeners.end(); ++l_d )
+  //   if ( l_d->second )
+  //   {
+  //     const list<SMESH_subMesh*>& smList = l_d->second->mySubMeshes;
+  //     list<SMESH_subMesh*>::const_iterator sm = smList.begin();
+  //     for ( ; sm != smList.end(); ++sm )
+  //       if ( _father != (*sm)->_father )
+  //         (*sm)->_father->Load();
+  //   }
 }
 
 //================================================================================
@@ -2054,6 +2496,7 @@ void SMESH_subMeshEventListener::ProcessEvent(const int          event,
         (*smIt)->ComputeStateEngine( event );
       break;
     case SMESH_subMesh::COMPUTE:
+    case SMESH_subMesh::COMPUTE_SUBMESH:
       if ( subMesh->GetComputeState() == SMESH_subMesh::COMPUTE_OK )
         for ( ; smIt != smEnd; ++ smIt)
           (*smIt)->ComputeStateEngine( SMESH_subMesh::SUBMESH_COMPUTED );
@@ -2111,21 +2554,48 @@ namespace {
 //================================================================================
 
 SMESH_subMeshIteratorPtr SMESH_subMesh::getDependsOnIterator(const bool includeSelf,
-                                                             const bool reverse)
+                                                             const bool reverse) const
 {
+  SMESH_subMesh *me = (SMESH_subMesh*) this;
   SMESH_subMesh *prepend=0, *append=0;
   if ( includeSelf ) {
-    if ( reverse ) prepend = this;
-    else            append = this;
+    if ( reverse ) prepend = me;
+    else            append = me;
   }
   typedef map < int, SMESH_subMesh * > TMap;
   if ( reverse )
   {
     return SMESH_subMeshIteratorPtr
-      ( new _Iterator( new SMDS_mapReverseIterator<TMap>( DependsOn() ), prepend, append ));
+      ( new _Iterator( new SMDS_mapReverseIterator<TMap>( me->DependsOn() ), prepend, append ));
   }
   {
     return SMESH_subMeshIteratorPtr
-      ( new _Iterator( new SMDS_mapIterator<TMap>( DependsOn() ), prepend, append ));
+      ( new _Iterator( new SMDS_mapIterator<TMap>( me->DependsOn() ), prepend, append ));
   }
 }
+
+//================================================================================
+/*!
+ * \brief  Find common submeshes (based on shared sub-shapes with other
+  * \param theOther submesh to check
+  * \param theSetOfCommon set of common submesh
+ */
+//================================================================================
+
+bool SMESH_subMesh::FindIntersection(const SMESH_subMesh* theOther,
+                                     std::set<const SMESH_subMesh*>& theSetOfCommon ) const
+{
+  int oldNb = theSetOfCommon.size();
+  // check main submeshes
+  const map <int, SMESH_subMesh*>::const_iterator otherEnd = theOther->_mapDepend.end();
+  if ( theOther->_mapDepend.find(this->GetId()) != otherEnd )
+    theSetOfCommon.insert( this );
+  if ( _mapDepend.find(theOther->GetId()) != _mapDepend.end() )
+    theSetOfCommon.insert( theOther );
+  // check common submeshes
+  map <int, SMESH_subMesh*>::const_iterator mapIt = _mapDepend.begin();
+  for( ; mapIt != _mapDepend.end(); mapIt++ )
+    if ( theOther->_mapDepend.find((*mapIt).first) != otherEnd )
+      theSetOfCommon.insert( (*mapIt).second );
+  return oldNb < theSetOfCommon.size();
+}