;;; Scheme Recursive Art Contest Entry
;;;
;;; Please do not include your name or personal info in this file.
;;;
;;; Title: Psychodelic Fern
;;;
;;; Description:
;;;   Psychodelic fern
;;;   Oh yea, so many colors
;;;   Recursive rainbow!

(define (sier d k i)
  (cond ((= i 1) (color 'red))
        ((= i 2) (color 'orange))
        ((= i 3) (color 'yellow))
        ((= i 4) (color 'lightgreen))
        ((= i 5) (color 'green))
        ((= i 6) (color 'darkgreen))
        ((= i 7) (color 'blue))
        ((= i 8) (color 'purple))
        ((= i 9) (color 'violet))
        ((= i 10) (color 'pink))
        ((= i 11) (color 'red))
        ((= i 12) (color 'orange))
        ((= i 13) (color 'yellow))
        ((= i 14) (color 'lightgreen))
        ((= i 15) (color 'green))
        (else (color 'darkgreen)))
  (begin_fill)
  (circle d)
  (end_fill)
  (if (< k 1) (circle d) (alternate (/ d (/ 5 4)) k i)))

(define (leg d k i)
  (penup)
  (lt 10)
  (fd (* d 3))
  (pendown)
  (sier (* d (/ 8 9)) (- k 1) i))

(define (alternate d k i)
  (let ((x (xcor)) (y (ycor)) (head (heading)))
    (leg d k (+ i 1))
    (seth head)
    (penup)
    (setpos x y)
    (bk d)
    (rt 90)
    (bk d)
    (pendown)
    (leg (/ d (/ 4 3)) (- k 1) (+ i 1))))

(define (draw)
  (speed 0)
  (penup)
  (bk 200)
  (pendown)
  (sier 80 15 1)
  (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)