;;; Scheme Recursive Art Contest Entry
;;;
;;; Please do not include your name or personal info in this file.
;;;
;;; Title: Factorial Star Art
;;;
;;; Description:
;;;   <Overlapping stars
;;;    create new stars. Recursion!
;;;    Dots are all that count.
;;;
;;;    Squirrel squirrel squirrel squirrel squirrel.
;;;    Squirrel squirrel squirrel squirrel squirrel squirrel squirrel.
;;;    Squirrel squirrel squirrel squirrel squirrel.>

(define color-list '(darkorange1 yellow2))
(define (color-choose n color-list)
  (define n (modulo n (length color-list)))
  (if (= n 0) (car color-list)
      (color-choose (- n 1) (cdr color-list))))
(define (right k) (rt 90) (fd k) (lt 90))
(define (left k) (lt 90) (fd k) (rt 90))
(define (repeat k func)
  (if (> k 0) (begin (func) (repeat (- k 1) func))
      'done))
(define (helper n)
  (fd (* 15 n)) (fact-draw (- n 1))
  (penup) (back (* 45 n)) (pendown) (lt (/ 360 n)))
(define (dot k)
  (color 'red)
  (right k) (begin_fill) (circle k) (end_fill) (left k))
(define (fact-draw n)
  (color (color-choose n color-list))
  (if (= n 0) (begin (dot 4) (color (color-choose n color-list)))
      (repeat n (lambda () (helper n)))))
(define (black-canvas)
  (color 'black) (setpos -1000 1000)
  (begin_fill) (goto 1000 1000) (goto 1000 -1000) (goto -1000 -1000) (end_fill))

(define (draw-procedure x-pos n)
  (penup) (seth 15) (setpos x-pos 0) (pendown)
  (fact-draw n))

(define (draw)
  (ht)
  (speed 0)
  (black-canvas)
  (draw-procedure -500 3)
  (draw-procedure -50 4)
  (draw-procedure 500 5)
  (exitonclick))

; Please leave this last line alone.  You may add additional procedures above
; this line.  All Scheme tokens in this file (including the one below) count
; toward the token limit.
(draw)