;;; Scheme Recursive Art Contest Entry
;;;
;;; Please do not include your name or personal info in this file.
;;;
;;; Title: <National Security Agency>
;;;
;;; Description:
;;;   <NSA is here
;;;    Patriotism goes gray
;;;    Liberty fades away.>
;;; Please don't take offense / take this super seriously
;;; A short haiku isn't meant to be a sweeping statement
;;; This is just something to think about
;;; Go Bears!

(define (cadr lst) (car(cdr lst)))

;Having 50 subboxes will result in a long run time. If you're trying this out, use 10 instead of 50
(define runs_in_stripe 50);This specifies how many boxes each stripe will be composed of

;By changing this number the flag can be scaled to an arbritrary large size, I was thinking about putting an eyeball it blue portion but it would have to go in as a background picture, which wouldn't scale
(define scaling_factor 400)

(define flag_red (cons .689 (cons .132 (cons .203 nil))))
(define flag_blue (cons .234(cons .233 (cons .430 nil))))
(define flag_white (cons 1 (cons 1 (cons 1 nil))))

(define (get_red lst)
  (car lst))

(define (get_green lst)
  (cadr lst))

(define (get_blue lst)
  (cadr(cdr lst)))

;This makes a simple box
(define (make_box ratio1 ratio2 multiplier)
  (repeat 2 (lambda () (begin (fd (* ratio1 multiplier)) (rt 90) (fd (* ratio2 multiplier)) (rt 90)))))

;This allows for boxes within boxes
(define (inner_box_spacing ratio1 ratio2 multiplier decrement)
  (define shift (* multiplier decrement))
  (begin (fd (/ (* ratio1 shift) 2)) (rt 90) (fd (/ (* ratio2 shift) 2)) (lt 90))
)

;(bgcolor .1 .1 .1)
(bgcolor 0 0 0)
(define (repeat k fn)
  (if (> k 0)
      (begin (fn) (repeat (- k 1) fn))
      'done))

;This helps make the colors of the flag fade away into the background
(define (greyify color_to_modify)
  (cons (* (get_red color_to_modify) .9) (cons (* (get_green color_to_modify) .9) (cons (* (get_blue color_to_modify) .9) nil)));The .9 specifies how fast the colors fade away
)

;This builds 'runs' number of boxes within each other
(define (inner_boxes ratio1 ratio2 scale_by runs color_vals)
  (if (> runs 0) (begin
  (fillcolor (get_red color_vals) (get_green color_vals) (get_blue color_vals))
  (pencolor (get_red color_vals) (get_green color_vals) (get_blue color_vals))

  (begin_fill)
  (make_box ratio1 ratio2 scale_by)
  (penup)
  (inner_box_spacing ratio1 ratio2 scale_by .1)
  (pendown)
  (make_box ratio1 ratio2 (* scale_by .9));The .9 in each call to make box determines how much smaller each box within the stripe gets.
  (end_fill)
  (begin_fill)
  (make_box ratio1 ratio2 (* scale_by .9))

  (inner_boxes ratio1 ratio2 (* scale_by .95) (- runs 1) (greyify color_vals));The .95 shifts the subsequent boxes, to create a sort of gradient. If it were .9 the center of the stripe would be darker instead of its edge
  ))
)

;This builds each stripe of the flag
;ratio1 is the width, ratio is the length
(define (build_stripes ratio1 ratio2 scale_by stripes_left org_color starting_x starting_y)
  (if (> stripes_left 0)( begin
    (penup)
    (setpos starting_x starting_y)  
    (pendown)
    (pencolor (get_red org_color) (get_green org_color) (get_blue org_color))
    (inner_boxes ratio1 ratio2 (* scale_by .9) runs_in_stripe org_color)
    (end_fill)
    (pencolor (get_red flag_red) (get_green flag_red) (get_blue flag_red))
    (build_stripes ratio1 ratio2 scale_by (- stripes_left 1) org_color starting_x (+ starting_y (* 2 ratio2 scale_by))))
  )
)

;This draws each stripe of the flag, and then draws the blue portion of the flag.
;The height to width ratio of the flag is 1:1.9
(define (draw)
  (ht);The turtle is hidden to speed up the drawing
  (setpos 0 0)
  (build_stripes 1.9 (/ 1 13) scaling_factor 3 flag_red 0 0);The US flag has 13 stripes, hence the 1/13
  (build_stripes 1.9 (/ 1 13) scaling_factor 3 flag_white 0 (* (/ 1 13) scaling_factor))
  (build_stripes 1.14 (/ 1 13) scaling_factor 4 flag_red (* .76 scaling_factor .9) (* 6 (/ 1 13) scaling_factor))
  (build_stripes 1.14 (/ 1 13) scaling_factor 3 flag_white (* .76 scaling_factor .9) (* 7 (/ 1 13) scaling_factor))
  (build_stripes .76 (* 1.09 (/ 7 13)) scaling_factor 1 flag_blue 0 (* (/ 12 13) scaling_factor)); * 1.09 shouldn't be neccesary
  (exitonclick))

  (speed 0)

; 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)