;;; Scheme Recursive Art Contest Entry
;;;
;;; Please do not include your name or personal info in this file.
;;;
;;; Title: <O U T R U N>
;;;
;;; Description:
;;;   <Reminiscent of
;;;    an eighties arcade machine:
;;;    it's all a e s t h e t i c s>

(define unit (/ 100 3))

(define (stripe top height col)
    (setpos 400 top)
    (pendown)
    (color col)
    (begin_fill)
    (setpos 400 (- top height))
    (setpos -400 (- top height))
    (setpos -400 top)
    (end_fill)
    (penup)
)

(define (gradient top col_list)
    (cond 
        ((not (null? col_list)) 
            (stripe top unit (car col_list))
            (gradient (- top unit) (cdr col_list))
        )
    )
)

(define (grid loc)
    (cond
        ((<= loc 400)
            (color "#00aeff")
            (setpos 0 20)
            (setheading (towards loc 5))
            (pendown)
            (forward 500)
            (setpos (- (xcor)) (ycor))
            (penup)
            (grid (+ loc 5))
        )
    )
)

(define (sun)
    (setpos 0 0)
    (pendown)
    (color "#ff7b00")
    (begin_fill)
    (circle 80)
    (end_fill)
    (penup)
    (stripe unit unit "#E200E5")
    (stripe (* 1.35 unit) 5 "#D200E0")
    (stripe (* 2 unit) 2 "#B300D8")
    (stripe 100 1 "#B300D8")
)

(define (mountain maxheight col)
    (define maxlen (floor (/ maxheight 2)))
    (setpos -400 maxlen)
    (color col)
    (begin_fill)
    (pendown)
    (define (mountain_help d)
        (cond
            ((< (xcor) 400)
                (cond
                    ((> (+ (ycor) maxlen) maxheight) (define d -1))
                    ((<= (- (ycor) maxlen) 0) (define d 1))
                )
                (if (> d 0) (setheading 45)
                    (setheading 135)
                )
                (forward (randint 0 maxlen))
                (mountain_help (randint -1 1))
            )
        )
    )
    (mountain_help (randint -1 1))
    (setpos 400 -5)
    (setpos -400 -5)
    (end_fill)
    (penup)
)

(define (draw)
    (penup)
    (speed 0)
    (define groundgrad (list "#281028" "#280F32" "#290E3D" "#2A0E48" "#2B0D53" "#2C0C5E" "#2D0C69" "#2E0B74" "#300A8A"))
    (gradient 0 groundgrad)
    (grid -400)
    (define skygrad (list "#5500BF" "#6400C3" "#7400C7" "#8400CB" "#9300CF" "#A300D4" "#B300D8" "#D200E0" "#E200E5"))
    (gradient 300 skygrad)
    (sun)
    (mountain 75 "#3c008c")
    (mountain 40 "#060023")
    (exitonclick))

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