コッホ曲線

turtle_koch_curve.rb

require 'oekaki'
require_relative 'turtle'

Width, Height = 600, 600

Oekaki.app width: Width, height: Height, title: "Koch curve" do
  draw do
    clear
    
    l = 500
    t = Turtle.new(Width, Height, self)
    t.color(0, 65535, 65535)
    t.move(l / 2, -150)
    t.dir = Vector[-1, 0]
    
    drawing = lambda do |length, depth|
      if depth.zero?
        t.forward(length)
      else
        drawing[length / 3, depth - 1]
        t.left(60)
        drawing[length / 3, depth - 1]
        t.right(120)
        drawing[length / 3, depth - 1]
        t.left(60)
        drawing[length / 3, depth - 1]
      end
    end
    
    3.times do
      drawing[l, 3]
      t.right(120)
    end
  end
end