const VertexArray &get_vertices() const { return vertices; }
void add_batch(const Batch &b);
const std::list<Batch> &get_batches() { return batches; }
const VertexArray &get_vertices() const { return vertices; }
void add_batch(const Batch &b);
const std::list<Batch> &get_batches() { return batches; }