;;; Scheme Recursive Art Contest Entry
;;;
;;; Please do not include your name or personal info in this file.
;;;
;;; Title: <One in Tree>
;;;
;;; Description:
;;;   <and it's recursive.
;;;    one in three a leaf in tree,
;;;    and it's recursive.>

; chance
(define (chance a b) (= 1 (randint a b)))

; draw a line with length l then turn right r degrees
(define (l_t_r l r) (fd l) (rt r))

; draw a rectangle with width w and height h
(define (rectangle w h)
    (define half_width (/ w 2))
    (begin_fill) (lt 90) (bk half_width) (l_t_r w 90) (l_t_r h 90)
    (l_t_r w 90) (l_t_r h 90) (l_t_r half_width 90) (end_fill)
)

; draw a leaf of approximate size s
(define (leaf s)
    (define half_size (/ s 2))
    (begin_fill) (color "#AFA44D") (lt 90) (bk half_size) (l_t_r s 90) (l_t_r s 30) 
    (l_t_r s 120) (l_t_r s 30) (l_t_r s 90) (l_t_r half_size 90) (end_fill)
)

; draw a three-leafed tree with starting tree size t, 
; parent branch/child branch ratio of r, 
; an angle of a1 in between left and middle branches,
; an angle of a2 in between middle and right branches,
; and a leaf size of l
(define (three_leafed_tree_special t r a1 a2 l)
    (define angle (/ (+ a1 a2) 2))
    (cond
    ((<= t l)
        (if (chance 1 3)
            (begin (leaf (/ l 2)) (color "#765F5F"))
            (begin (fd t) (bk t))))
        (else (color "#765F5F") 
            (cond 
                ((and (chance 1 11) (<= t 55)) (three_leafed_tree_special (* t 0.72) r a1 a2 l))
                ((and (chance 1 8) (<= t 88)) (three_leafed_tree_special (+ t 6) r a1 a2 l))
                ((chance 1 4) (three_leafed_tree_special t r a2 a1 l))
                ((chance 1 10) (three_leafed_tree_special t r (- a1 6) (+ a2 6) l))
                ((chance 1 8) (three_leafed_tree_special t r (+ a1 7) (- a2 7) l))
                (else 
                    (rectangle (* 0.1 t) t)
                    (fd t) (lt angle) (three_leafed_tree_special (* t r) r a1 a2 l) (rt a1) 
                    (three_leafed_tree_special (* t r) r a1 a2 l) (rt a2) 
                    (three_leafed_tree_special (* t r) r a1 a2 l) (lt angle) (bk t)
                )
            )
        )
    )
)

(define (draw)
    (bgcolor "#304A77") (speed 0) (tp_goto 0 -240)

    (three_leafed_tree_special 200 0.65 68 38 23)

    (lt 90) (begin_fill) (color "#4A7857") (circle 1000) (end_fill)

    (ht) (exitonclick)
)

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