google3/third_party/libigl/include/igl/on_boundary.cpp

// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla Public License
// v. 2.0. If a copy of the MPL was not distributed with this file, You can
// obtain one at http://mozilla.org/MPL/2.0/.
#include "on_boundary.h"

// IGL includes
#include "sort.h"
#include "face_occurrences.h"

// STL includes

template <typename IntegerT>
IGL_INLINE void igl::on_boundary(
  const std::vector<std::vector<IntegerT> > & T,
  std::vector<bool> & I,
  std::vector<std::vector<bool> > & C)
{
  using namespace std;
  if(T.empty())
  {
    I.clear();
    C.clear();
    return;
  }

  switch(T[0].size())
  {
    case 3:
    {
      // Get a list of all faces
      vector<vector<IntegerT> > F(T.size()*3,vector<IntegerT>(2));
      // Gather faces, loop over tets
      for(int i = 0; i< (int)T.size();i++)
      {
        assert(T[i].size() == 3);
        // get face in correct order
        F[i*3+0][0] = T[i][1];
        F[i*3+0][1] = T[i][2];
        F[i*3+1][0] = T[i][2];
        F[i*3+1][1] = T[i][0];
        F[i*3+2][0] = T[i][0];
        F[i*3+2][1] = T[i][1];
      }
      // Counts
      vector<int> FC;
      face_occurrences(F,FC);
      C.resize(T.size(),vector<bool>(3));
      I.resize(T.size(),false);
      for(int i = 0; i< (int)T.size();i++)
      {
        for(int j = 0;j<3;j++)
        {
          assert(FC[i*3+j] == 2 || FC[i*3+j] == 1);
          C[i][j] = FC[i*3+j]==1;
          // if any are on boundary set to true
          I[i] = I[i] || C[i][j];
        }
      }
      return;
    }
    case 4:
    {
      // Get a list of all faces
      vector<vector<IntegerT> > F(T.size()*4,vector<IntegerT>(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
        F[i*4+0][0] = T[i][1];
        F[i*4+0][1] = T[i][3];
        F[i*4+0][2] = T[i][2];
        // get face in correct order
        F[i*4+1][0] = T[i][0];
        F[i*4+1][1] = T[i][2];
        F[i*4+1][2] = T[i][3];
        // get face in correct order
        F[i*4+2][0] = T[i][0];
        F[i*4+2][1] = T[i][3];
        F[i*4+2][2] = T[i][1];
        // get face in correct order
        F[i*4+3][0] = T[i][0];
        F[i*4+3][1] = T[i][1];
        F[i*4+3][2] = T[i][2];
      }
      // Counts
      vector<int> FC;
      face_occurrences(F,FC);
      C.resize(T.size(),vector<bool>(4));
      I.resize(T.size(),false);
      for(int i = 0; i< (int)T.size();i++)
      {
        for(int j = 0;j<4;j++)
        {
          assert(FC[i*4+j] == 2 || FC[i*4+j] == 1);
          C[i][j] = FC[i*4+j]==1;
          // if any are on boundary set to true
          I[i] = I[i] || C[i][j];
        }
      }
      return;
    }
  }


}

#include "list_to_matrix.h"
#include "matrix_to_list.h"

template <typename DerivedT, typename DerivedI, typename DerivedC>
IGL_INLINE void igl::on_boundary(
  const Eigen::MatrixBase<DerivedT>& T,
  Eigen::PlainObjectBase<DerivedI>& I,
  Eigen::PlainObjectBase<DerivedC>& C)
{
  assert(T.cols() == 0 || T.cols() == 4 || T.cols() == 3);
  using namespace std;
  using namespace Eigen;
  // Cop out: use vector of vectors version
  vector<vector<typename DerivedT::Scalar> > vT;
  matrix_to_list(T,vT);
  vector<bool> vI;
  vector<vector<bool> > vC;
  on_boundary(vT,vI,vC);
  list_to_matrix(vI,I);
  list_to_matrix(vC,C);
}


#ifdef IGL_STATIC_LIBRARY
// Explicit template instantiation
// generated by autoexplicit.sh
template void igl::on_boundary<Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Array<bool, -1, 1, 0, -1, 1>, Eigen::Array<bool, -1, 3, 0, -1, 3> >(Eigen::MatrixBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Array<bool, -1, 1, 0, -1, 1> >&, Eigen::PlainObjectBase<Eigen::Array<bool, -1, 3, 0, -1, 3> >&);
template void igl::on_boundary<Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1> >(Eigen::MatrixBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> >&, Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> >&);
template void igl::on_boundary<Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Array<bool, -1, 1, 0, -1, 1>, Eigen::Array<bool, -1, -1, 0, -1, -1> >(Eigen::MatrixBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Array<bool, -1, 1, 0, -1, 1> >&, Eigen::PlainObjectBase<Eigen::Array<bool, -1, -1, 0, -1, -1> >&);
#endif