hilbert.scm

(define (hilbert order width)
  (let loop ((count 0)
             (shape (h0 width)))
    (if (= count order)
        shape
        (let* ((next-shape (shrink-shape shape 0.5))
               (upper-left (reflect-shape (rotate-shape next-shape (* 3.14159 1.5))))
               (upper-right (translate-shape next-shape 'east width))
               (lower-left (translate-shape next-shape 'south width))
               (lower-left* (reflect-shape (rotate-shape lower-left (* 3.14159 .5))))
               (lower-right (translate-shape next-shape 'southeast width)))
          (loop (+ count 1)
                (merge-shapes upper-left upper-right lower-right lower-left*))))))