Method compute

tools/Wires/Attributes/WireVertexPeriodicIndexAttribute.cpp:73–130

using namespace WireVertexPeriodicIndexAttributeHelper;

void WireVertexPeriodicIndexAttribute::compute(const WireNetwork& network) {
    const Float EPS = 1e-6;
    const size_t dim = network.get_dim();
    const size_t num_vertices = network.get_num_vertices();
    const MatrixFr& vertices = network.get_vertices();

    const VectorF bbox_min = vertices.colwise().minCoeff();
    const VectorF bbox_max = vertices.colwise().maxCoeff();
    const VectorF bbox_size = bbox_max - bbox_min;

    HashGrid::Ptr grid = HashGrid::create(EPS, dim);
    m_values.resize(num_vertices, 1);
    for (size_t i=0; i<num_vertices; i++) {
        const VectorF& v = vertices.row(i);
        m_values(i, 0) = i;
        grid->insert(i, v);
    }

    FunctionList transforms = get_periodic_transforms(bbox_size);
    for (auto trans: transforms) {
        std::vector<bool> visited(num_vertices, false);
        for (size_t i=0; i<num_vertices; i++) {
            if (visited[i]) continue;
            const VectorF& v = vertices.row(i);

            if ((v - bbox_min).cwiseAbs().minCoeff() < EPS) {
                VectorF opposite = trans(v);
                VectorI opposite_indices = grid->get_items_near_point(opposite);
                VectorI current_indices = grid->get_items_near_point(v);

                if (opposite_indices.size() == 0) continue;

                std::vector<int> indices(opposite_indices.size() +
                        current_indices.size());
                std::copy(opposite_indices.data(), opposite_indices.data() +
                        opposite_indices.size(), indices.begin());
                std::copy(current_indices.data(), current_indices.data() +
                        current_indices.size(), indices.begin() +
                        opposite_indices.size());

                auto get_value = [&](size_t i) {
                    return size_t(m_values(i,0));
                };

                std::vector<size_t> periodic_indices(indices.size());
                std::transform(indices.begin(), indices.end(),
                        periodic_indices.begin(), get_value);
                size_t label = *std::min_element(
                        periodic_indices.begin(), periodic_indices.end());

                for (auto idx : indices) {
                    m_values(idx, 0) = label;
                    visited[idx] = true;
                }
            }
        }
    }
}