;;; Scheme Recursive Art Contest Entry
;;;
;;; Please do not include your name or personal info in this file.
;;;
;;; Title: Roses on the River
;;;
;;; Description:
;;;   Wilt in your comfort,
;;;   or leap off the binding stem. 
;;;   Journey the unknown.

(define scale 300)
(define nscale (- 0 scale))
(define penupflag  True)
(define (sq x)
	(* x x))
    
(define (drawjpoint x y)
        (define mycolor (computejulia x y))
    	(define r (quotient mycolor 65536)) 
    	(define r1 (modulo mycolor 65536)) 
    	(define g (quotient r1 256))
	(if (> g 200) (define g (quotient g 10)) )
	(if (> g 100) (define g (- g 80)) )
	(define b (modulo r1 256))
	(setpos x y)
	(if penupflag  (begin (pendown)
    			(define penupflag False)))
	(rgb (modulo r  256)  g  b))

(define (loop2 f x y)
	(define yx (- y x) )
	(define r (+  (sq  x)  (sq  y) ))
        (if (or (and (< yx  scale) (> yx nscale ))  
	        (< r  (sq scale))) 
		(f x y))
	(if (> y nscale)
	    (loop2 f x  (- y 1))))

(define (drawj width height)
    (drawjrow width height)
    (if (> width nscale)
	    (drawj (- width 1)  height)))

(define (drawjrow row col)
    (penup)
    (define penupflag True)
    (loop2 drawjpoint row col))


(define (helper x y  level)
    (if (> (+ (sq x) (sq  y)) 4)
        level
	(begin (define newx  (+ (- (sq  x) (sq y))  0.1 ))
    		(define newy  (+ (* 2 (* x y)) -0.7))
	       (helper newx newy (+ level 1)))))

(define (computejulia x y)
  (* 899191 (helper (/ x scale)  (/ y scale)  0)))

(define (draw)
  (clear)
  (drawj scale scale)
  (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)