let w = 5;

let y = 0;

let left, right, state;

​

function setup() {

  createCanvas(600, 600);

​

​

  let total = width / w;

  // Initialize all cells to state 0 (inactive).

  for (let i = 0; i < total; i++) {

    cells[i] = 0;

  }

  cells[floor(total / 2)] = 1;

  background(255);

}

​

function draw() {

  for (let i = 0; i < cells.length; i++) {

    let x = i * w;

    noStroke();

    fill(cells[i]);

    square(x, y, w);

  }

​

  y += w;

​

  let nextCells = [];

​

  let len = cells.length;

  for (let i = 0; i < len; i++) {

    left = cells[(i - 1 + len) % len];

    right = cells[(i + 1) % len];

    state = cells[i];

    let newState = calculateState(left, state, right);

    nextCells[i] = newState;

  }

​

  cells = nextCells;

}

​

function calculateState(a, b, c) {

  if (a > 0.5 && b < 0.5 && c < 0.5) return a;

  if (a > 0.5 && b > 0.5 && c < 0.5) return a + b;

  if (a > 0.5 && b > 0.5 && c > 0.5) return 0;

  if (a > 0.5 && b < 0.5 && c > 0.5) return a + c;

  if (a < 0.5 && b > 0.5 && c > 0.5) return b + c;

  if (a < 0.5 && b > 0.5 && c < 0.5) return b;

  if (a < 0.5 && b < 0.5 && c > 0.5) return c;

  if (a < 0.5 && b < 0.5 && c < 0.5) return 0;  

}

​