let timeSlider;

let lifeSpan = 250; // How long should each generation live

let lifeCounter = 0; // Timer for cycle of generation

let food;

let generations = 0;

​

function setup() {

  createCanvas(640, 240);

  ml5.tf.setBackend("cpu");

  for (let i = 0; i < 50; i++) {

    creatures[i] = new Creature(random(width), random(height));

  }

  glow = new Glow();

  timeSlider = createSlider(1, 20, 1);

  timeSlider.position(10, 220);

}

​

function draw() {

  background(255);

​

  glow.show();

​

  for (let creature of creatures) {

    creature.show();

  }

​

  for (let i = 0; i < timeSlider.value(); i++) {

    for (let creature of creatures) {

      creature.seek(glow);

      creature.update(glow);

    }

    glow.update();

    lifeCounter++;

  }

​

  if (lifeCounter > lifeSpan) {

    normalizeFitness();

    reproduction();

    lifeCounter = 0;

    generations++;

  }

  fill(0);

  noStroke();

  text("Generation #: " + generations, 10, 18);

  text("Cycles left: " + (lifeSpan - lifeCounter), 10, 36);

}

​

function normalizeFitness() {

  let sum = 0;

  for (let creature of creatures) {

    sum += creature.fitness;

  }

  for (let creature of creatures) {

    creature.fitness = creature.fitness / sum;

  }

}

​

function reproduction() {

  let nextCreatures = [];

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

    let parentA = weightedSelection();

    let parentB = weightedSelection();

    let child = parentA.crossover(parentB);

    child.mutate(0.1);

    nextCreatures[i] = new Creature(random(width), random(height), child);

  }

  creatures = nextCreatures;

}

​

function weightedSelection() {

  let index = 0;

  let start = random(1);

  while (start > 0) {

    start = start - creatures[index].fitness;

    index++;

  }

  index--;

  return creatures[index].brain;

}

​