;;; Scheme Recursive Art Contest Entry
;;;
;;; Please do not include your name or personal info in this file.
;;;
;;; Title: Nuclear Eclipse
;;;
;;; Description:
;;;    Tornado of fire,
;;;    Rays of red yellow and orange,
;;;    Power of turtles.


(define hue (cons-stream 1 (cons-stream 2 (cons-stream 3 hue))))
(define c (cons-stream "red" (cons-stream "yellow" (cons-stream "red" c))))

(define (tornado ridges size angle c x)
  (if (zero? ridges) #t
    (begin
    (forward size)
    (right angle)
    (pendown)
    (cond ((= (car c) 1) (color (rgb 1 (/ (+ 0 x) 2) 0)))
          ((= (car c) 2) (color (rgb 1 (- 1 (/ x 2)) 0)))
          ((= (car c) 3) (color (rgb 1 (/ (+ 0.5 (/ x 2)) 1.5) 0))))
    (begin_fill)
    (circle size)
    (end_fill)
    (penup)
    (tornado (- ridges 1) (* size 1.05) (* angle 0.99) (cdr-stream c) (+ x .01))
      )
    )
  )

(define (cornerright) (right 90))

(define (corner)
  (begin_fill)
  (circle 300 90)
  (cornerright)
  (forward 1000)
  (cornerright)
  (forward 1300)
  (cornerright)
  (forward 1300)
  (cornerright)
  (forward 1000)
  (end_fill)
  (cornerright)
  (circle 300 90))

(define (four-corners x)
  (if (= x 0) #t
    (begin (corner) (four-corners (- x 1)))))

(define (rays times clr thick)
  (if (= times 0) #t
    (begin
      (color clr)
      (circle 300 (/ 720 thick))
      (cornerright)
      (begin_fill)
      (forward 1000)
      (cornerright)
      (circle -1300 (/ 360 thick))
      (cornerright)
      (forward 1000)
      (cornerright)
      (circle 300 (/ 360 thick))
      (end_fill)
      (rays (- times 1) clr thick))))

(define (draw)
  ; YOUR CODE HERE
  (showturtle)
  (bgcolor "orange")
  (speed 10)
  (tornado 50 40 210 hue 0)
  (setposition 0 300)
  (setheading 270)
  (color "white")
  (pendown)
  (four-corners 4)
  (rays 7 (rgb 1 0.5 0) 100)
  (rays 17 (rgb 1 0.75 0) 100)
  (rays 19 (rgb 1 0.25 0) 100)
  (rays 7 (rgb 1 0.5 0) 100)
  (exitonclick))

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