ヒルベルト曲線

turtle_hilbert_curve.rb

require 'oekaki'
require_relative 'turtle'

Width, Height = 600, 600

Oekaki.app width: Width, height: Height, title: "Hilbert curve" do
  draw do
    clear
    
    depth = 5
    
    l = 500
    t = Turtle.new(Width, Height, self)
    t.color(0xffff, 0x7dff, 0)
    t.move(-l / 2, l / 2)
    step = l / (2 ** depth - 1)
    
    drawing = lambda do |depth, angle|
      if depth.zero?
        return
      else
        t.right(angle)
        drawing[depth - 1, -angle]
        t.forward(step)
        t.left(angle)
        drawing[depth - 1,  angle]
        t.forward(step)
        drawing[depth - 1,  angle]
        t.left(angle)
        t.forward(step)
        drawing[depth - 1, -angle]
        t.right(angle)
      end
    end
    
    drawing[depth, 90]
  end
end