;;; Scheme Recursive Art Contest Entry
;;;
;;; Please do not include your name or personal info in this file.
;;;
;;; Title: Pane/Pain
;;;
;;; Description:
;;;   Stained glass pass no pass
;;;    Broken rainbow of my dreams
;;;    window panes of pain

(define (draw)
(define LIMIT 10) ; limit is the smallest distance between points for recursion

(define (make-posn a b)
  (lambda (v) (if v a b)))

(define (mid x y)
    (/ (+ x y) 2))

(define (mid2 w x y z)
(/ (+ x y z w) 4))

(define (colorfunction x)
                  (cond ((= (modulo x 5) 0) "red")
                        ((= (modulo x 5) 1) "orange")
                        ((= (modulo x 5) 2) "yellow")
                        ((= (modulo x 5) 3) "green")
                        (else "violet")))





(define (mid-point a-posn b-posn)
(make-posn (mid (a-posn true) (b-posn true))
           (mid (a-posn false) (b-posn false))))


(define (center-point a-posn b-posn c-posn d-posn)
(make-posn (mid2 (a-posn true) (b-posn true) (c-posn true) (d-posn true))
           (mid2 (a-posn false) (b-posn false) (c-posn false) (d-posn false))))


(define (too-small? a b c d)
(and (< (abs (- (a true) (b true))) LIMIT)
     (< (abs (- (a true) (c true))) LIMIT)
     (< (abs (- (c true) (b true))) LIMIT)
     (< (abs (- (a true) (d true))) LIMIT)
     (< (abs (- (b true) (d true))) LIMIT)
     (< (abs (- (c true) (d true))) LIMIT)
     (< (abs (- (a false) (b false))) LIMIT)
     (< (abs (- (a false) (c false))) LIMIT)
     (< (abs (- (c false) (b false))) LIMIT)
     (< (abs (- (a false) (d false))) LIMIT)
     (< (abs (- (b false) (d false))) LIMIT)
     (< (abs (- (c false) (d false))) LIMIT)))


(define (draw-solid-line a b)
  (penup)
  (goto (a true) (a false))
  (pendown)
  (goto (b true) (b false))
  (penup))

(define (draw-square a b c d)

     (begin_fill)
     (color "black")
     (draw-solid-line a b)
     (draw-solid-line b c)
     (draw-solid-line c d)
     (draw-solid-line d a)

     (color (colorfunction (* (d true) (* (b false) (* (d false) (* (c false) (* (c true) (* (a false) (* (b true ) (a true))))))))))

     (end_fill)
     )


     (define (rug a b c d)
       (cond [(too-small? a b c d) true]
             [else (and (draw-square a b c d)

                        (rug a (mid-point a (mid-point a b)) (center-point a b c d) (mid-point a (mid-point a d)))
                        (rug (mid-point a (mid-point a b)) (center-point a b c d) (mid-point b (mid-point a b)) (mid-point a b))
                        (rug b (mid-point b (mid-point a b))  (center-point a b c d)  (mid-point b (mid-point b c)))
                        (rug (mid-point b (mid-point c b))  (center-point a b c d)  (mid-point c (mid-point b c)) (mid-point b c))
                        (rug c  (mid-point c (mid-point b c))  (center-point a b c d)  (mid-point c (mid-point c d)))
                        (rug (mid-point c (mid-point c d))  (center-point a b c d)  (mid-point d (mid-point d c)) (mid-point d c))
                        (rug d  (mid-point d (mid-point a d))  (center-point a b c d) (mid-point d (mid-point c d)))
                        (rug (mid-point a (mid-point d a))  (center-point a b c d)  (mid-point d (mid-point a d)) (mid-point a d))
                   )]))



(rug (make-posn -300 -300)
          (make-posn 300 -300)
          (make-posn 300 300)
          (make-posn -300 300))
  (exitonclick))

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