(load "stk-turtle-stuff")

(cs)

;Draws a spiral that consists of 1/4 circles with radius increase by the fibonacci sequence.
(define (goldenspiral radius previous count) (if (> count 0) (begin (circle radius 45)
    (goldenspiral (+ previous radius) radius (- count 1)))))

;Colors of the rainbow.
(define colorlst (list "#ff0000" "#ff0000" "#ff7f00" "#ff7f00" "#ffff00" "#ffff00" "#00ff00" "#00ff00" "#0000ff" "#0000ff" "#8b00ff" "#8b00ff"))

;Draws 12 goldenspirals spaced by a fibonacci sequence of starting angles.
(define (metagolden start count degrees previous colorlst) (if (> count 0)
    (begin (penup) (setposition 0 0) (setheading (+ start degrees)) (pendown) (color (car colorlst))
        (goldenspiral 1 1 14)
            (metagolden start (- count 1) (+ degrees previous) degrees (cdr colorlst)))))

;Paints canvas black.
(color "#000000")
(define (shader x y) (if (= x 350) (if (< y 350) (begin (goto x y) (shader -350 (+ y 1))))
    (begin (goto x y) (shader 350 y))))

(shader -350 -350)

;Draws the two spirals at 180 degrees to each other.
(metagolden 0 12 0 1 colorlst)
(metagolden 180 12 0 1 colorlst)