# Let's have some fun with Rule 110:
# https://en.wikipedia.org/wiki/Rule_110

import turtle
import random

# enumerate next state for Rule 110
ca_rule = [0, 1, 1, 1, 0, 1, 1, 0]

# Note we can use the same encoding trick for all 1D CAs. 
# For example, for Rule 54 we can have:
# ca_rule = [0, 1, 1, 0, 1, 1, 0, 0]

def next_state(state):
  n = []
  j = len(state)
  for i in range(j):
    # Let's assume that the two edges of the list are connected
    left = i - 1
    right = i + 1 if i < j - 1 else 0
    n.append(ca_rule[4 * state[left] + 2 * state[i] + state[right]])

  return n

game_len = 120
x_pos = -100
y_pos = 200

window = turtle.Screen()
window.bgcolor('light gray')

pen = turtle.Turtle()
pen.speed(20)
pen.color('dark blue')
pen.pensize(2)
pen.shape('classic')

# create a random starting state 
curr_state = [ random.choice([1, 0]) for x in range(game_len) ]

for g in range(game_len):
  pen.penup()
  pen.setx(x_pos)
  pen.sety(y_pos)
  for c in curr_state:
    if c == 1:
      pen.pendown()
    else:
      pen.penup()

    pen.forward(3)
  
  curr_state = next_state(curr_state)
  y_pos -= 3