type t val id : t val translate : float -> float -> float -> t val scale : float -> float -> float -> t val rotatex : float -> t val rotatey : float -> t val rotatez : float -> t val compose : t -> t -> t val apply_to_point : t -> Point.t -> Point.t val apply_to_vect : t -> Vector.t -> Vector.t val fudge_id : unit -> t * t