face_quad.C

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// The libMesh Finite Element Library.
// Copyright (C) 2002-2014 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner

// 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.

// 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

// C++ includes

// Local includes
#include "libmesh/face_quad.h"
#include "libmesh/edge_edge2.h"

namespace libMesh
{


// ------------------------------------------------------------
// Quad class member functions
dof_id_type Quad::key (const unsigned int s) const
{
  libmesh_assert_less (s, this->n_sides());

  switch (s)
    {
    case 0:
      return
        this->compute_key (this->node(0),
                           this->node(1));

    case 1:
      return
        this->compute_key (this->node(1),
                           this->node(2));

    case 2:
      return
        this->compute_key (this->node(2),
                           this->node(3));

    case 3:
      return
        this->compute_key (this->node(3),
                           this->node(0));

    default:
      libmesh_error_msg("Invalid side s = " << s);
    }

  libmesh_error_msg("We'll never get here!");
  return 0;
}



UniquePtr<Elem> Quad::side (const unsigned int i) const
{
  libmesh_assert_less (i, this->n_sides());

  Elem* edge = new Edge2;

  switch (i)
    {
    case 0:
      {
        edge->set_node(0) = this->get_node(0);
        edge->set_node(1) = this->get_node(1);
        break;
      }
    case 1:
      {
        edge->set_node(0) = this->get_node(1);
        edge->set_node(1) = this->get_node(2);
        break;
      }
    case 2:
      {
        edge->set_node(0) = this->get_node(2);
        edge->set_node(1) = this->get_node(3);
        break;
      }
    case 3:
      {
        edge->set_node(0) = this->get_node(3);
        edge->set_node(1) = this->get_node(0);
        break;
      }
    default:
      libmesh_error_msg("Invalid side i = " << i);
    }

  return UniquePtr<Elem>(edge);
}



bool Quad::is_child_on_side(const unsigned int c,
                            const unsigned int s) const
{
  libmesh_assert_less (c, this->n_children());
  libmesh_assert_less (s, this->n_sides());

  // A quad's children and nodes don't share the same ordering:
  // child 2 and 3 are swapped;
  unsigned int n = (c < 2) ? c : 5-c;
  return (n == s || n == (s+1)%4);
}



unsigned int Quad::opposite_side(const unsigned int side_in) const
{
  libmesh_assert_less (side_in, 4);

  return (side_in + 2) % 4;
}



unsigned int Quad::opposite_node(const unsigned int node_in,
                                 const unsigned int side_in) const
{
  libmesh_assert_less (node_in, 8);
  libmesh_assert_less (node_in, this->n_nodes());
  libmesh_assert_less (side_in, this->n_sides());
  libmesh_assert(this->is_node_on_side(node_in, side_in));

  static const unsigned char side02_nodes_map[] =
    {3, 2, 1, 0, 6, 255, 4, 255};
  static const unsigned char side13_nodes_map[] =
    {1, 0, 3, 2, 255, 7, 255, 5};

  switch (side_in)
    {
    case 0:
    case 2:
      return side02_nodes_map[node_in];
    case 1:
    case 3:
      return side13_nodes_map[node_in];
    default:
      libmesh_error_msg("Unsupported side_in = " << side_in);
    }

  libmesh_error_msg("We'll never get here!");
  return 255;
}


Real Quad::quality (const ElemQuality q) const
{
  switch (q)
    {

    case DISTORTION:
    case DIAGONAL:
    case STRETCH:
      {
        // Diagonal between node 0 and node 2
        const Real d02 = this->length(0,2);

        // Diagonal between node 1 and node 3
        const Real d13 = this->length(1,3);

        // Find the biggest and smallest diagonals
        if ( (d02 > 0.) && (d13 >0.) )
          if (d02 < d13) return d02 / d13;
          else return d13 / d02;
        else
          return 0.;
        break;
      }

    default:
      return Elem::quality(q);
    }

  return Elem::quality(q);
}






std::pair<Real, Real> Quad::qual_bounds (const ElemQuality q) const
{
  std::pair<Real, Real> bounds;

  switch (q)
    {

    case ASPECT_RATIO:
      bounds.first  = 1.;
      bounds.second = 4.;
      break;

    case SKEW:
      bounds.first  = 0.;
      bounds.second = 0.5;
      break;

    case TAPER:
      bounds.first  = 0.;
      bounds.second = 0.7;
      break;

    case WARP:
      bounds.first  = 0.9;
      bounds.second = 1.;
      break;

    case STRETCH:
      bounds.first  = 0.25;
      bounds.second = 1.;
      break;

    case MIN_ANGLE:
      bounds.first  = 45.;
      bounds.second = 90.;
      break;

    case MAX_ANGLE:
      bounds.first  = 90.;
      bounds.second = 135.;
      break;

    case CONDITION:
      bounds.first  = 1.;
      bounds.second = 4.;
      break;

    case JACOBIAN:
      bounds.first  = 0.5;
      bounds.second = 1.;
      break;

    case SHEAR:
    case SHAPE:
    case SIZE:
      bounds.first  = 0.3;
      bounds.second = 1.;
      break;

    case DISTORTION:
      bounds.first  = 0.6;
      bounds.second = 1.;
      break;

    default:
      libMesh::out << "Warning: Invalid quality measure chosen." << std::endl;
      bounds.first  = -1;
      bounds.second = -1;
    }

  return bounds;
}




const unsigned short int Quad::_second_order_adjacent_vertices[4][2] =
  {
    {0, 1}, // vertices adjacent to node 4
    {1, 2}, // vertices adjacent to node 5
    {2, 3}, // vertices adjacent to node 6
    {0, 3}  // vertices adjacent to node 7
  };



const unsigned short int Quad::_second_order_vertex_child_number[9] =
  {
    99,99,99,99, // Vertices
    0,1,2,0,     // Edges
    0            // Interior
  };



const unsigned short int Quad::_second_order_vertex_child_index[9] =
  {
    99,99,99,99, // Vertices
    1,2,3,3,     // Edges
    2            // Interior
  };

} // namespace libMesh