#lang racket
(require (planet wcy/mpost-wrapper))
(provide main)
(define (main)
  (let* ((z0 (point 50 50))
         (z1 (rotate 90 z0))
         (z2 (rotate 90 z1))
         (z3 (rotate 90 z2))
         (carre (op-- z0 z1 z2 z3 'cycle))
         (s 0.01))
    (for ((i (in-range 1  s (- s) )))
         (fill (scale i carre)
               #:withcolor (op* i 'white)))))