startshape grid

gridsize = 20
width = 0.1

CF::Tile = [s gridsize]

shape grid {
  loop gridsize [y 1]
    loop gridsize [x 1]
      diag[]
}

shape diag
rule {
  SQUARE [r 45 s (width) (sqrt(2) + width)]
}
rule {
  SQUARE [r -45 s (width) (sqrt(2) + width)]
}
