fractal-curves

import turtle
import math

WIDTH, HEIGHT = 1200, 1200

def generate_thue_morse_sequence(n):
    value = 0
    for item in range(n):
        if (len(bin(item ^ (item - 1))) - 2) % 2:
            value = 1 - value
        yield value


def draw_koch_snowflake(n_iterations, colour="white"):
    koch.color(colour)

    def instruction_0():
        koch.left(180)

    def instruction_1():
        koch.forward(WIDTH / (3**n_iterations))
        koch.left(60)


    instructions = {
        0: instruction_0,
        1: instruction_1,
    }

    for idx in range(3):
        sequence = generate_thue_morse_sequence(2 ** (n_iterations * 2 - 1))
        # print(list(sequence))
        for instruction in sequence:
            instructions[instruction]()
            window.update()

if __name__ == "__main__":
    window = turtle.Screen()
    window.bgcolor(0.2, 0.2, 0.2)
    window.setup(WIDTH, HEIGHT)
    window.tracer(0)

    koch = turtle.Turtle()
    koch.pensize(2)
    koch.penup()
    koch.setposition((WIDTH / 6), -(WIDTH / 6) * math.sin(math.pi / 6))
    koch.hideturtle()
    koch.pendown()

    draw_koch_snowflake(1)
    draw_koch_snowflake(2, "light green")
    draw_koch_snowflake(3, "turquoise")
    draw_koch_snowflake(4, "firebrick")
    draw_koch_snowflake(5, "dark salmon")
    turtle.done()