backward_step_mesh.template.cc

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//LIC// ====================================================================
//LIC// This file forms part of oomph-lib, the object-oriented, 
//LIC// multi-physics finite-element library, available 
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//LIC// 
//LIC//    Version 1.0; svn revision $LastChangedRevision$
//LIC//
//LIC// $LastChangedDate$
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//LIC// Copyright (C) 2006-2016 Matthias Heil and Andrew Hazel
//LIC// 
//LIC// This library is free software; you can redistribute it and/or
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//LIC// License as published by the Free Software Foundation; either
//LIC// version 2.1 of the License, or (at your option) any later version.
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//LIC// Lesser General Public License for more details.
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#ifndef OOMPH_BACKWARD_STEP_MESH_TEMPLATE_CC
#define OOMPH_BACKWARD_STEP_MESH_TEMPLATE_CC

#include<set>
#include<map>
#include "backward_step_mesh.template.h"

namespace oomph
{


 
 
//=================================================================
 /// \short Actual build function. Pass overall number of elements in the 
 /// horizontal and vertical directions, nx and ny, and the corresponding 
 /// dimensions, lx and ly. nx_cut_out and ny_cut_out elements
 /// are cut out from the lower right corner to create the
 /// (reversed) backward step geometry. Timestepper defaults 
 /// to Steady.
//=================================================================
 template<class ELEMENT>
 void BackwardStepQuadMesh<ELEMENT>::build_mesh(
  const unsigned &nx,
  const unsigned &ny, 
  const unsigned& nx_cut_out,
  const unsigned& ny_cut_out,
  const double &lx, 
  const double &ly)
 {

  // Mesh can only be built with 2D Qelements.
  MeshChecker::assert_geometric_element<QElementGeometricBase,ELEMENT>(2);
  
  // By default nobody's claiming any nodes
  std::map<Node*,bool> keep;
  
  // Get elements outside lower right block
  Vector<FiniteElement*> el_retained_pt;
  Vector<FiniteElement*> el_killed_pt;
  for (unsigned i=0;i<nx;i++)
   {     
    for (unsigned j=0;j<ny;j++)
     {
      FiniteElement* el_pt=this->finite_element_pt(i+nx*j);
      if ((i>(nx_cut_out-1))&&(j<ny_cut_out))
       {
        el_killed_pt.push_back(el_pt);
       }
      else
       {
        el_retained_pt.push_back(el_pt);
        unsigned nnod_el=el_pt->nnode();
        for (unsigned jj=0;jj<nnod_el;jj++)
         {
          keep[el_pt->node_pt(jj)]=true;
         }
       }
     }
   }
  
  
  // By default nobody's claiming the nodes; also store old
  // boundary ids
  std::map<Node*,std::set<unsigned> > boundaries; 
  unsigned nnod=this->nnode();
  for (unsigned j=0;j<nnod;j++)
   {
    std::set<unsigned>* aux_pt=0;
    this->node_pt(j)->get_boundaries_pt(aux_pt);
    if (aux_pt!=0)
     {
      boundaries[this->node_pt(j)]=(*aux_pt);
     }
   }
  
  // Remove information about boundary nodes
  this->remove_boundary_nodes();
  
  // Reset number of boundaries
  this->set_nboundary(6);
  
  // Kill superfluous nodes
  Vector<Node*> node_backup_pt(this->Node_pt);
  this->Node_pt.clear();
  for (unsigned j=0;j<nnod;j++)
   {
    Node* nod_pt=node_backup_pt[j];
    if (keep[nod_pt])
     {
      this->Node_pt.push_back(nod_pt);
      std::set<unsigned> aux=boundaries[nod_pt];
      for (std::set<unsigned>::iterator it=boundaries[nod_pt].begin();
           it!=boundaries[nod_pt].end();it++)
       {
        unsigned b=(*it);
        if (b>0) b+=2;
        this->add_boundary_node(b,nod_pt);
       }
     }
    else
     {
      delete node_backup_pt[j];
     }
   }
  
  // Add nodes to new boundary 1
  unsigned i=nx_cut_out-1;
  for (unsigned j=0;j<ny_cut_out;j++)
   {
    FiniteElement* el_pt=this->finite_element_pt(i+nx*j);     
    unsigned nnod_1d=el_pt->nnode_1d();
    for (unsigned jj=0;jj<nnod_1d;jj++)
     {
      unsigned jnod=(nnod_1d-1)+jj*nnod_1d;
      if (!(el_pt->node_pt(jnod)->is_on_boundary()))
       {
        Node* nod_pt=el_pt->node_pt(jnod);
        this->convert_to_boundary_node(nod_pt);
       }
      this->add_boundary_node(1,el_pt->node_pt(jnod));
     }
   }
  
  // Add nodes to new boundary 2
  unsigned j=ny_cut_out;
  for (unsigned i=nx_cut_out;i<nx;i++)
   {
    FiniteElement* el_pt=this->finite_element_pt(i+nx*j);     
    unsigned nnod_1d=el_pt->nnode_1d();
    for (unsigned jj=0;jj<nnod_1d;jj++)
     {
      unsigned jnod=jj;
      if (!(el_pt->node_pt(jnod)->is_on_boundary()))
       {
        Node* nod_pt=el_pt->node_pt(jnod);
        this->convert_to_boundary_node(nod_pt);
       }
      this->add_boundary_node(2,el_pt->node_pt(jnod));
     }
   }
  
  
  
  // Kill redundant elements   
  this->Element_pt.clear();
  unsigned n_retained=el_retained_pt.size();
  for (unsigned e=0;e<n_retained;e++)
   {
    this->Element_pt.push_back(el_retained_pt[e]);
   }
  unsigned n_killed=el_killed_pt.size();
  for (unsigned e=0;e<n_killed;e++)
   {
    delete el_killed_pt[e];
   }
  
  // Re-setup lookup scheme that establishes which elements are located
  // on the mesh boundaries
  this->setup_boundary_element_info();
 }

}

#endif