opengl-test   scheme

;; opengl-test includes two sources
;; of constant wind speed
;;
;; bottom->top: straight up the middle
;; left->right: oscillates from back to front
;;
;; You might need to slow the rate of this
;; temporal recursion down if your machine
;; doesn't cope.  (i.e. 3000 to 5000 or more
;;
;; standard impromptu callback
(define opengl-test
  (lambda (time degree)
    (if (< (+ time 0) (now))
      (println 'gl-behind (- time (now))))