;;; Fichier spiro.s / 28 fevrier 2000
;;; d'apres Tim Hickey : spirograph.jsc
;;; http://www.cs.brandeis.edu/~tim/Packages/Jscheme/latest/demos/spirograph.jsc

(define b (button "Vas-y!"))
(add b appletwin)
(validate appletwin)
(define sam (turtle 100 100 appletwin))

(define (Baction) 
  (penup sam)  
  (goto (+ 100 (* (random) 150)) 
           (+ 100 (* (random) 150)) sam) 
  (pendown sam)
  (draw-spirograph 30 (+ 50 (* (random) 130)) 100 sam))

(refresh appletwin)
(addCallback b Baction appletwin)



(define (draw-spirograph n angle x tortue)
  (sleep 100) (go x tortue) (turn angle tortue)
  (if (> n 0) (draw-spirograph (- n 1) angle x tortue) 'fin))