-;; (define (move-shots shots)
-;; (cond ((null? shots) '())
-;; (else
-;; (let* ((sh (car shots))
-;; (x (assoc-ref sh 'x)) (y (assoc-ref sh 'y))
-;; (angle (assoc-ref sh 'angle))
-;; (r (degrees-to-radians (- angle))))
-;; (set! x (+ x (* 10 (sin r))))
-;; (set! y (+ y (* 10 (cos r))))
-;; (cond ((and (<= x max-x)
-;; (>= x min-x)
-;; (<= y max-y)
-;; (>= y min-y))
-;; (cons `((x . ,x) (y . ,y) (angle . ,angle))
-;; (move-shots (cdr shots))))
-;; (else
-;; (move-shots (cdr shots))))))))
-
-;; (define (make-asteroids n)
-;; (define (xy n r)
-;; (let ((n2 (- (random (* n 2)) n)))
-;; (cond ((and (< n2 r) (>= n2 0)) r)
-;; ((and (> n2 (- r)) (< n2 0)) (- r))
-;; (else n2))))
-
-;; (cond ((= n 0) '())
-;; (else
-;; (cons `((x . ,(xy max-x 20)) (y . ,(xy max-y 20)) (angle . 0) (vx . 1) (vy . 1) (size . 95))
-;; (make-asteroids (- n 1))))))