;;; Scheme Recursive Art Contest Entry
;;;
;;; Please do not include your name or personal info in this file.
;;;
;;; Title: <Postmodern Holiday>
;;;
;;; Description:
;;;   <Dashing through the snow
;;;    In a one-horse open sleigh
;;;    Laughing all the way!>

(define (draw)
  ; *YOUR CODE HERE*
  (speed 0) (ht) (pu) (setposition -200 -200)

  (define (christmas_dict index)
    (cond ((= index 0) "#66df9a")
          ((= index 1) "#CC0000")
          ((= index 2) "#E60000")
          ((= index 3) "#FF0000")
          ((= index 4) "#FF1919")
          ((= index 5) "#FF3333")
          ((= index 6) "#FF4D4D")
          ((= index 7) "#FF6666")
          ((= index 8) "#FF8080")
          ((= index 9) "#007A5C")
          ((= index 10) "#008F6B")
          ((= index 11) "#00A37A")
          ((= index 12) "#00B88A")
          ((= index 13) "#00CC99")
          ((= index 14) "#19D1A3")
          ((= index 15) "#33D6AD")
          ((= index 16) "#4DDBB8")
          ((= index 17) "#66E0C2")
          ((= index 18) "#80E6CC")))


  ;changes the color of pen
  (define (rand_color) (color (christmas_dict (random 19))))

  ;draw recursively smaller concentric squares around point(x, y)
  (define (concentric_squares x y len)
    (if (> len 5) (begin (rand_color)
                         (pu) (goto (- x (/ len 2)) y) (pd)
                         (begin_fill) (goto (- x (/ len 2)) (- y (/ len 2)))
                                      (goto (+ x (/ len 2)) (- y (/ len 2)))
                                      (goto (+ x (/ len 2)) (+ y (/ len 2)))
                                      (goto (- x (/ len 2)) (+ y (/ len 2)))
                                      (goto (- x (/ len 2)) y) (end_fill)
                         (concentric_squares x y (- len 10)))))

  ;draw recursively smaller concentric circles around point (x, y)
  (define (concentric_circles x y rad)
    (if (> rad 0) (begin (rand_color) (pu) (goto (+ x rad) y) (pd)
                          (begin_fill) (circle rad) (end_fill)
                          (concentric_circles x y (- rad 5)))))

  ;draw concentric squares from point (a, b) to point (x, y)
  (define (draw_squares a b x y numsteps len)
    (begin (rand_color) (pu)
    (if (> numsteps 0) (begin (concentric_squares a b len)
                              (draw_squares (+ (/ (- x a) (+ numsteps 1)) a) (+ (/ (- y b) (+ numsteps 1)) b) x y (- numsteps 1) len))
                       (goto x y))))

  ;draw concentric circles from point (a, b) to point (x, y)
  (define (draw_circles a b x y numsteps rad)
    (begin (rand_color) (pu)
    (if (> numsteps 0) (begin (concentric_circles a b rad)
                              (draw_circles (+ (/ (- x a) (+ numsteps 1)) a) (+ (/ (- y b) (+ numsteps 1)) b) x y (- numsteps 1) rad))
                       (goto x y))))

  ;base point (x0, y0), unit vectors defined by (xi, xj) and (yi, yj), number of recursions n
  (define (recursive_art x0 y0 xi xj yi yj n)
    (begin (pu)
    (if (> n 0) (begin (recursive_art x0 y0 (/ yi 2) (/ yj 2) (/ xi 2) (/ xj 2) (- n 1))
                       (draw_circles (+ x0 (/ xi 2)) (+ y0 (/ xj 2)) (+ x0 (/ (+ xi yi) 2)) (+ y0 (/ (+ xj yj) 2)) 2 30)
                       (recursive_art (+ x0 (/ xi 2)) (+ y0 (/ xj 2)) (/ xi 2) (/ xj 2) (/ yi 2) (/ yj 2) (- n 1))
                       (draw_circles (+ x0 (/ xi 2)) (+ y0 (/ xj 2)) (+ x0 (/ (+ xi yi) 2)) (+ y0 (/ (+ xj yj) 2)) 5 10)
                       (recursive_art (+ x0 (/ xi 2) (/ yi 2)) (+ y0 (/ xj 2) (/ yj 2)) (/ xi 2) (/ xj 2) (/ yi 2) (/ yj 2) (- n 1))
                       (draw_circles (+ x0 (/ xi 2) (/ yi 2)) (+ y0 (/ xj 4) (/ yj 4)) (+ x0 (/ (+ xi yi) 2)) (+ y0 (/ (+ xj yj) 2)) 1 20)
                       (draw_squares (+ x0 (/ xi 2) (/ yi 2)) (+ y0 (/ xj 2) (/ yj 2)) (+ x0 (/ (+ xi yi) 2)) (+ y0 (/ (+ xj yj) 2)) 1 100)
                       (recursive_art (+ x0 (/ xi 2) yi) (+ y0 (/ xj 2) yj) (/ (- yi) 2) (/ (- yj) 2) (/ (- xi) 2) (/ (- xj) 2) (- n 1))
                       (draw_circles (+ x0 (/ xi 2) yi) (+ y0 (/ xj 2) yj) (+ x0 (/ (+ xi yi) 2)) (+ y0 (/ (+ xj yj) 2)) 5 10)
                       (recursive_art x0 y0 xi xj yi yj (- n 1))))))

  (recursive_art -200 -200 450 0 0 450 3)

  (exitonclick))


;Inspired by the hilbert-curve

; 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)