;;; Scheme Recursive Art Contest Entry
;;;
;;; Please do not include your name or personal info in this file.
;;;
;;; Title: The fib-meister
;;;
;;; Description:
;;;    Fibonacci helped
;;;    Not really sure how he did
;;;    But it looks pretty neat


;;;                  
(define (list-size n) 
	(if (= n 0) 
		nil
		(cons 0 (list-size (- n 1)))
		)
	)

;;; helps define position
(define (list-Change lst n)
	(cond
		((null? lst) nil)
		((= n 0) (cons (+ 1 (car lst)) (cdr lst)))
		(else (cons (car lst) (list-Change (cdr lst) (- n 1))))
		)

	)
;;; Used for determining posiition of list for fib seq
(define (list-pos n)
	(cond
		((= n 0)     1)
		((= n 1)     2)
		((= n 2)     3)
		((= n 3)     4)
		((= n 5)     5)
		((= n 8)     6)
		((= n 13)    7)
		((= n 21)    8)
		((= n 34)    9)
		((= n 55)   10)
		((= n 89)   11)
		((= n 144)  12)
		((= n 233)  13)
		((= n 377)  14)

		)
	)

;;; List adding mechanic
(define (adder lst1 lst2)
	(cond
		((null? lst1) nil)
		(else (cons (+ (car lst1) (car lst2)) (adder (cdr lst1) (cdr lst2))))
		)
	)

;; get elemet
(define (get-item lst n)
	(cond
		((= n 0) (car lst))
		((null? lst) nil)
		(else (get-item (cdr lst) (- n 1)))
		)
	)

;; main event
(define (fib lst n start1 start2)
	(define p (get-item lst (list-pos (car lst))))
	(goto  start1 start2)
	(cond
		((= n 1)
			(define x (list-Change lst (- 1 n)))
			(define y (list-change x 2))
			(define p (get-item y 2))	
			
			y
			)
		((= n 0)
			(define x (list-Change lst (- 1 n)))
			x
			)
		(else (define x (adder (fib lst (- n 1) start1 start2) (fib lst (- n 2) start1 start2)  ))
			(define y (list-change x (list-pos (car x))))
			(define p (get-item y (list-pos (car y))))
			(forward (* 20 (car y)))
			(left p)	
			y
			)	
		)
	)
(define (cross-out start end)
	(cond
		((> start end) (penup) nil)
		(else
			(penup)
			(goto start -400)
			(pendown)
			(goto (* -1 start) 400)
			(cross-out (+ start 10) end)
			)
		)
	)
(define (wierdforward start1 start end)
    (cond
		((> start1 end) (penup) nil)
		(else
			(penup)
			(goto 0 start)
			(pendown)
			(goto  end 0)
			(wierdforward start1 (+ start 5) (- end 5))
			)
		)
	)
(define (wierdbackward start1 start end)
    (cond
		((< start1 start) (penup) nil)
		(else
			(penup)
			(goto 0 start)
			(pendown)
			(goto  end 0)
			(wierdbackward start1 (+ start 5) (+ end 5))
			)
		)
	)




(define (draw)
  (penup)
  (bgcolor (rgb 0 0 0))
  (speed 0)
  (goto 0 0)
  (pendown)
  (color (rgb 1 1 1))
  (define lst (list-size 16))
  
  (wierdforward 0 0 500)
  (wierdforward -500 -500 0)
  (wierdbackward 0 -500 0)
  (wierdbackward 500 0 -500)
  (penup)
  (goto 250 250)
  (pendown)
  (color (rgb 1 0 1))
  (fib lst 13 250 250)
  (goto 250 250)
  (penup)
  (goto -250 -250)
  (pendown)
  (fib lst 13 -250 -250)
  (goto -250 -250)
  (penup)
  ;(color (rgb 0 0 0))
  ;(cross-out -500 500)
  (goto 1000 1000)

  (exitonclick)
)

; Please leave this last line alone.  You may add additional procedures above
; this line.
(draw)