Fractals Invaders in doodle

Inspired by jtarbell's original fractal invaders, I took the liberty of implementing this in CHICKEN Scheme using doodle.

(use doodle matchable (srfi 1))

(define block-width 3)
(define block-height 3)
(define block-rows 5)
(define block-cols 6)

(new-doodle width: 840
            height: 420
            background: solid-white)

(define (block x y row col)
  (let*  ((x0 (+ x (* col block-width)))
          (y0 (+ y (* row block-height)))
          (x1 (+ x0 block-width))
          (y1 (+ y0 block-height)))
    (list x0 y0 block-width block-height)))

(define (color v)
  (if (= v 0) solid-black solid-white))

(define (mirror grid)
  (map (lambda (lst)
         (append lst (cdr (reverse lst)))) grid))

(define (draw-blocks x y blks color-chooser)
  (let loop ((bs (mirror blks))
             (row 0))
    (cond ((null? bs) #t)
           (fold (lambda (b col)
                   (apply filled-rectangle `(,@(block x y row col)
                                             ,(color-chooser b)))
                   (add1 col))
                 (car bs))
           (loop (cdr bs)
                 (add1 row))))))

(define (random-blocks)
  (list-tabulate block-rows
                 (lambda _
                   (list-tabulate (/ block-cols 2)
                                  (lambda _ (random 2))))))

(define (random-critter! x y)
  (draw-blocks x y (random-blocks) color))

(define (invaders)
  (let outer ((x 3))
    (if (< x doodle-width)
          (let inner ((y 3))
            (if (< y doodle-height)
                  (random-critter! x y)
                  (inner (+ y (* 2 block-width block-cols))))))
          (outer (+ x (* 2 block-height block-rows))))))

(define *painting* #t)

(world-inits (lambda ()

(world-changes (lambda (events dt exit)
                  (lambda (e)
                    (match e
                           (('key 'pressed #\esc)
                            (exit #t))
                           (('key 'pressed #\space)
                            (set! *painting* (not *painting*)))
                           (else (void))))
                 (when *painting*


It turned out to be a nice coffee break hack and the resulting images leave a lot of room for imagination. Maybe this is a nice way to create sprites for the next retro arcarde game procedurally? Try tuning the block rows and columns!


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