interiornode.hh

// -*- tab-width: 4; indent-tabs-mode: nil -*-
#ifndef DUNE_PDELAB_CONSTRAINTS_INTERIORNODE_HH
#define DUNE_PDELAB_CONSTRAINTS_INTERIORNODE_HH
 
#include <array>
 
#include <dune/grid/common/gridenums.hh>
#include <dune/geometry/referenceelements.hh>
#include <dune/localfunctions/common/interfaceswitch.hh>
#include <dune/localfunctions/common/localkey.hh>
 
#include <dune/typetree/typetree.hh>
 
namespace Dune {
  namespace PDELab {
 
 
    class InteriorNodeConstraints
      : public TypeTree::LeafNode
    {
      std::vector<bool> interior;
    public:
      enum{doBoundary=false};
      enum{doProcessor=false};
      enum{doSkeleton=false};
      enum{doVolume=true};
 
 
      template<typename P, typename EG, typename LFS, typename T>
      void volume (const P& param, const EG& eg, const LFS& lfs, T& trafo) const
      {
        typedef typename EG::Entity Entity;
        enum { dim = Entity::dimension };
 
        // update component
        typename T::RowType empty;
        typedef typename LFS::Traits::SizeType size_type;
        typedef FiniteElementInterfaceSwitch<
          typename LFS::Traits::FiniteElementType
          > FESwitch;
        for (size_type i=0; i<lfs.size(); i++){
          const LocalKey& key = FESwitch::coefficients(lfs.finiteElement()).localKey(i);
          assert(key.codim() == dim && "InteriorNodeConstraints only work for vertex DOFs");
          assert(key.index() == 0   && "InteriorNodeConstraints only work for P1 shape functions");
 
          // subentity index
          unsigned int local_idx = key.subEntity();
 
          // global idx
          unsigned int idx = lfs.gridFunctionSpace().gridView().indexSet().subIndex(eg.entity(), local_idx, dim);
 
          // update constraints
          if (interior[idx])
              trafo[lfs.dofIndex(i)] = empty;
        }
 
      }
 
      const std::vector<bool> & interiorNodes() const
      {
        return interior;
      }
 
      template<typename GV>
      void updateInteriorNodes(const GV & gv)
      {
        // update vector size
        const int dim = GV::dimension;
        typedef typename GV::Grid::ctype ctype;
 
        interior.resize(gv.indexSet().size(dim));
        for(std::size_t i=0; i< interior.size(); i++)
          interior[i] = true;
 
        // loop over all cells
        for(const auto& entity : elements(gv))
        {
          // find boundary faces & associated vertices
          for (const auto& intersection : intersections(gv,entity))
          {
            if (intersection.boundary())
            {
              // boundary face
              unsigned int f = intersection.indexInInside();
              // remember associated vertices
              auto refelem = Dune::ReferenceElements<ctype,dim>::simplex();
              assert(entity.geometry().type().isSimplex() && "InteriorNodeConstraints only work for simplicial meshes");
              unsigned int sz = refelem.size(f,1, dim);
              assert(sz == dim);
              for (unsigned int v = 0; v < sz; ++v)
              {
                unsigned int local_idx = refelem.subEntity (f,1, v,dim);
                unsigned int idx = gv.indexSet().subIndex(entity, local_idx, dim);
                interior[idx] = false;
              }
            }
          }
        }
      }
    };
 
  } // end namespace PDELab
} // end namespace Dune
 
#endif // DUNE_PDELAB_CONSTRAINTS_INTERIORNODE_HH