turtle_sierpinski.py

# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT

import board
from adafruit_turtle import turtle


def getMid(p1, p2):
    return ((p1[0] + p2[0]) / 2, (p1[1] + p2[1]) / 2)  # find midpoint


def triangle(points, depth):

    turtle.penup()
    turtle.goto(points[0][0], points[0][1])
    turtle.pendown()
    turtle.goto(points[1][0], points[1][1])
    turtle.goto(points[2][0], points[2][1])
    turtle.goto(points[0][0], points[0][1])

    if depth > 0:
        triangle(
            [points[0], getMid(points[0], points[1]), getMid(points[0], points[2])],
            depth - 1,
        )
        triangle(
            [points[1], getMid(points[0], points[1]), getMid(points[1], points[2])],
            depth - 1,
        )
        triangle(
            [points[2], getMid(points[2], points[1]), getMid(points[0], points[2])],
            depth - 1,
        )


turtle = turtle(board.DISPLAY)
big = min(board.DISPLAY.width / 2, board.DISPLAY.height / 2)
little = big / 1.4
seed_points = [[-big, -little], [0, big], [big, -little]]  # size of triangle
triangle(seed_points, 4)

while True:
    pass