libigl_Martin/boundary_faces.cpp

#include "boundary_faces.h"
#include "face_occurences.h"

// IGL includes
#include "sort.h"

// STL includes
#include <map>
#include <iostream>

template <typename IntegerT, typename IntegerF>
IGL_INLINE void igl::boundary_faces(
  const std::vector<std::vector<IntegerT> > & T,
  std::vector<std::vector<IntegerF> > & F)
{
  using namespace std;
  using namespace igl;

  // Get a list of all faces
  vector<vector<IntegerF> > allF(T.size()*4,vector<IntegerF>(3));
  // Gather faces, loop over tets
  for(int i = 0; i< (int)T.size();i++)
  {
    assert(T[i].size() == 4);
    // get face in correct order
    allF[i*4+0][0] = T[i][1];
    allF[i*4+0][1] = T[i][3];
    allF[i*4+0][2] = T[i][2];
    // get face in correct order
    allF[i*4+1][0] = T[i][0];
    allF[i*4+1][1] = T[i][2];
    allF[i*4+1][2] = T[i][3];
    // get face in correct order
    allF[i*4+2][0] = T[i][0];
    allF[i*4+2][1] = T[i][3];
    allF[i*4+2][2] = T[i][1];
    // get face in correct order
    allF[i*4+3][0] = T[i][0];
    allF[i*4+3][1] = T[i][1];
    allF[i*4+3][2] = T[i][2];
  }
  // Counts
  vector<int> C;
  face_occurences(allF,C);

  int twos = (int) count(C.begin(),C.end(),2);
  // Resize output to fit number of ones
  F.resize(allF.size() - twos);
  int k = 0;
  for(int i = 0;i< (int)allF.size();i++)
  {
    if(C[i] == 1)
    {
      assert(k<(int)F.size());
      F[k] = allF[i];
      k++;
    }
  }

}

#ifndef IGL_NO_EIGEN
#include "list_to_matrix.h"
#include "matrix_to_list.h"

template <typename DerivedT, typename DerivedF>
IGL_INLINE void igl::boundary_faces(
  const Eigen::PlainObjectBase<DerivedT>& T,
  Eigen::PlainObjectBase<DerivedF>& F)
{
  assert(T.cols() == 0 || T.cols() == 4);
  using namespace std;
  using namespace Eigen;
  using namespace igl;
  // Cop out: use vector of vectors version
  vector<vector<typename Eigen::PlainObjectBase<DerivedT>::Scalar> > vT;
  matrix_to_list(T,vT);
  vector<vector<typename Eigen::PlainObjectBase<DerivedF>::Scalar> > vF;
  boundary_faces(vT,vF);
  list_to_matrix(vF,F);
}
#endif


#ifndef IGL_HEADER_ONLY
// Explicit template specialization
template void igl::boundary_faces<Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> >&);
#endif