(define make-timer* (foreign-lambda timer "al_create_timer" double))
(define (make-timer d)
  (let ((t (make-timer* d)))
    (set-finalizer! t free-timer!)
    t))

(define free-timer! (foreign-lambda void "al_destroy_timer" timer))

(define usec->sec (foreign-lambda* double ((double x)) "C_return(ALLEGRO_USECS_TO_SECS(x));"))
(define msec->sec (foreign-lambda* double ((double x)) "C_return(ALLEGRO_MSECS_TO_SECS(x));"))
(define bps->sec (foreign-lambda* double ((double x)) "C_return(ALLEGRO_BPS_TO_SECS(x));"))
(define bpm->sec (foreign-lambda* double ((double x)) "C_return(ALLEGRO_BPM_TO_SECS(x));"))

(define timer-start! (foreign-lambda void "al_start_timer" timer))
(define timer-stop! (foreign-lambda void "al_stop_timer" timer))
(define timer-started? (foreign-lambda bool "al_get_timer_started" timer))
(define timer-speed (foreign-lambda double "al_get_timer_speed" timer))
(define timer-speed-set! (foreign-lambda void "al_set_timer_speed" timer double))
(define timer-count (foreign-lambda integer64 "al_get_timer_count" timer))
(define timer-count-set! (foreign-lambda void "al_set_timer_count" timer integer64))
(define timer-count-add! (foreign-lambda void "al_add_timer_count" timer integer64))
(define timer-source (foreign-lambda event-source "al_get_timer_event_source" timer))