message: Use boundary_opposite_vertex_simplex_range instead of boundary_simplex_range in cech
diff: @@ -74,25 +74,15 @@ class Cech_blocker {
  bool is_min_enclos_ball = false;
  // for each face of simplex sh, test outsider point is indeed inside enclosing ball, if yes, take it and exit loop, otherwise, new sphere is circumsphere of all vertices
  - for (auto face : sc_ptr_->boundary_simplex_range(sh)) {
  - // Find which vertex of sh is missing in face. We rely on the fact that simplex_vertex_range is sorted.
  - auto longlist = sc_ptr_->simplex_vertex_range(sh);
  - auto shortlist = sc_ptr_->simplex_vertex_range(face);
  -
  - auto longiter = std::begin(longlist);
  - auto shortiter = std::begin(shortlist);
  - auto enditer = std::end(shortlist);
  - while(shortiter != enditer && *longiter == *shortiter) { ++longiter; ++shortiter; }
  - auto extra = *longiter; // Vertex_handle
  -
  + for (auto face_opposite_vertex : sc_ptr_->boundary_opposite_vertex_simplex_range(sh)) {
  Sphere sph;
  - auto k = sc_ptr_->key(face);
  + auto k = sc_ptr_->key(face_opposite_vertex.first);
  if(k != sc_ptr_->null_key()) {
  sph = cc_ptr_->get_cache().at(k);
  }
  else {
  Point_cloud face_points;
  - for (auto vertex : sc_ptr_->simplex_vertex_range(face)) {
  + for (auto vertex : sc_ptr_->simplex_vertex_range(face_opposite_vertex.first)) {
  face_points.push_back(cc_ptr_->get_point(vertex));
  #ifdef DEBUG_TRACES
  std::clog << "#(" << vertex << ")#";
  @@ -100,13 +90,13 @@ class Cech_blocker {
  }
  sph = get_sphere(face_points.cbegin(), face_points.cend());
  // Put edge sphere in cache
  - sc_ptr_->assign_key(face, cc_ptr_->get_cache().size());
  + sc_ptr_->assign_key(face_opposite_vertex.first, cc_ptr_->get_cache().size());
  cc_ptr_->get_cache().push_back(sph);
  // Clear face_points
  face_points.clear();
  }
  - // Check if the minimal enclosing ball of current face contains the extra point
  - if (kernel_.squared_distance_d_object()(sph.first, cc_ptr_->get_point(extra)) <= sph.second) {
  + // Check if the minimal enclosing ball of current face contains the extra point/opposite vertex
  + if (kernel_.squared_distance_d_object()(sph.first, cc_ptr_->get_point(face_opposite_vertex.second)) <= sph.second) {
  #ifdef DEBUG_TRACES
  std::clog << "center: " << sph.first << ", radius: " << radius << std::endl;
  #endif // DEBUG_TRACES
  