import turtle
# Set up Constants
ANGLES = [60, -120, 60, 0]
SIZE_OF_SNOWFLAKE = 300
def get_input_depth():
""" Obtain input from user and convert to an int"""
message = 'Please provide the depth (0 or a positive interger):'
value_as_string = input(message)
while not value_as_string.isnumeric():
print('The input must be an integer!')
value_as_string = input(message)
return int(value_as_string)
def setup_screen(title, background='white', screen_size_x=640, screen_size_y=320, tracer_size=800):
print('Set up Screen')
turtle.title(title)
turtle.setup(screen_size_x, screen_size_y)
turtle.hideturtle()
turtle.penup()
turtle.backward(240)
# Batch drawing to the screen for faster rendering
turtle.tracer(tracer_size)
turtle.bgcolor(background) # Set the background colour of the screen
def draw_koch(size, depth):
if depth > 0:
for angle in ANGLES:
draw_koch(size / 3, depth - 1)
turtle.left(angle)
else:
turtle.forward(size)
depth = get_input_depth()
setup_screen('Koch Snowflake (depth ' + str(depth) + ')',
background='black',
screen_size_x=420, screen_size_y=420)
# Set foreground colours
turtle.color('sky blue')
# Ensure snowflake is centred
turtle.penup()
turtle.setposition(-180,0)
turtle.left(30)
turtle.pendown()
# Draw three sides of snowflake
for _ in range(3):
draw_koch(SIZE_OF_SNOWFLAKE, depth)
turtle.right(120)
# Ensure that all the drawing is rendered
turtle.update()
print('Done')
turtle.done()
