Method init_face_adjacencies

src/Connectivity/MeshConnectivity.cpp:256–324

}

void MeshConnectivity::init_face_adjacencies(Mesh* mesh) {
    if (face_adjacencies_computed()) return;
    if (!vertex_adjacencies_computed())
        init_vertex_adjacencies(mesh);

    const size_t num_faces = mesh->get_num_faces();
    const size_t vertex_per_face = mesh->get_vertex_per_face();

    std::vector<IndexSet> neighbor_faces(num_faces);
    std::vector<IndexSet> neighbor_voxels(num_faces);

    for (size_t i=0; i<num_faces; i++) {
        VectorI face = mesh->get_face(i);
        IndexSet& face_neighbors = neighbor_faces[i];

        assert(face.size() == vertex_per_face);
        std::map<int, int> face_counter;
        for (size_t j=0; j<vertex_per_face; j++) {
            VectorI neighbors = get_vertex_adjacent_faces(face[j]);
            size_t num_neighbors = neighbors.size();
            for (size_t k=0; k<num_neighbors; k++) {
                if (face_counter.find(neighbors[k]) == face_counter.end()) {
                    face_counter[neighbors[k]] = 1;
                } else {
                    face_counter[neighbors[k]] += 1;
                }
            }
        }
        for (std::map<int, int>::const_iterator itr = face_counter.begin();
                itr != face_counter.end(); itr++) {
            if (itr->second == 2) {
                face_neighbors.insert(itr->first);
            }
        }
    }

    for (size_t i=0; i<num_faces; i++) {
        VectorI face = mesh->get_face(i);
        IndexSet& face_neighbors = neighbor_voxels[i];

        std::map<int, int> voxel_counter;
        for (size_t j=0; j<vertex_per_face; j++) {
            VectorI neighbors = get_vertex_adjacent_voxels(face[j]);
            size_t num_neighbors = neighbors.size();
            for (size_t k=0; k<num_neighbors; k++) {
                if (voxel_counter.find(neighbors[k]) == voxel_counter.end()) {
                    voxel_counter[neighbors[k]] = 1;
                } else {
                    voxel_counter[neighbors[k]] += 1;
                }
            }
        }
        for (std::map<int, int>::const_iterator itr = voxel_counter.begin();
                itr != voxel_counter.end(); itr++) {
            if (itr->second == 3) {
                face_neighbors.insert(itr->first);
            }
        }