sidef-scripts/Image/sierpinski_square_curve.sf

#!/usr/bin/ruby

# https://rosettacode.org/wiki/Sierpinski_square_curve

include('LSystem/LSystem.sf')

var rules = Hash(
    x => 'xF-F+F-xF+F+xF-F+F-x',
)

var lsys = LSystem(
    width:  510,
    height: 510,

    xoff: -505,
    yoff: -254,

    len:   4,
    angle: 90,
    color: 'dark green',
)

lsys.execute('F+xF+F+xF', 5, "sierpiński_square_curve.png", rules)