Function get_non_zero_index

tools/Wires/Inflator/PhantomMeshGenerator.cpp:38–51

    template<typename Derived>
    VectorI get_non_zero_index(const Eigen::MatrixBase<Derived>& data) {
        std::list<size_t> indices;
        const size_t num_entries = data.size();
        for (size_t i=0; i<num_entries; i++) {
            if (data(i, 0) != 0) {
                indices.push_back(i);
            }
        }

        const size_t num_non_zero_entries = indices.size();
        VectorI result(num_non_zero_entries);
        std::copy(indices.begin(), indices.end(), result.data());
        return result;
    }

    void dilate(const MatrixIr& edges, std::vector<bool>& indicator) {
        const size_t num_edges = edges.rows();