(** An immutable 2D vector class. 

    @author Victor Nicollet *)

(** A vector as a pair of coordinates. *)
type vector = { x : float; y : float }

(** The horizontal 'right' vector *)
val right : vector

(** The vertical 'up' vector *)
val up : vector

(** The zero vector *)
val zero : vector

(** Are two vectors equal? *)
val equal : vector -> vector -> bool

(** Add two vectors together *)
val ( ++ ) : vector -> vector -> vector

(** Substract a vector from another *)
val ( -- ) : vector -> vector -> vector

(** Scale a vector *)
val ( *+ ) : float -> vector -> vector

(** The squared length of a vector *)
val sqlen : vector -> float

(** The length of a vector *)
val len : vector -> float

(** Exception thrown when expecting a non-null vector *)
exception ZeroVector

(** The unit vector corresponding to a vector. 
    @raise ZeroVector if the vector is zero. *)
val normalize : vector -> vector

(** Dot product *)
val dot : vector -> vector -> float