// Daniel Shiffman

  // http://natureofcode.com

​

  // Pathfinding Flowfield w/ Genetic Algorithms

​

  // This example produces an obstacle course with a start and finish

  // Virtual "creatures" are rewarded for making it closer to the finish

​

  // Each creature's DNA is a "flowfield" of PVectors that

  // determine steering vectors for each cell on the screen

​

  let gridscale = 10; // Scale of grid is 1/24 of screen size

​

  // DNA needs one vector for every spot on the grid

  // (it's like a pixel array, but with vectors instead of colors)

  let dnasize;

​

  let lifetime; // How long should each generation live

​

​

  let population; // Population

  let lifecycle; // Timer for cycle of generation

  let recordtime; // Fastest time to target

  let target; // Target position

  let start; // Start position

  let diam = 24; // Size of target

​

  let obstacles; //an array list to keep track of all the obstacles!

​

  let debug = false;

​

  let newObstacle = null;

​

  let info;

​

  function setup() {

    createCanvas(640, 360);

    info = createP('');

    dnasize = floor(width / gridscale) * floor(height / gridscale);

    lifetime = width / 3;

​

    // Initialize let iables

    lifecycle = 0;

    recordtime = lifetime;

    target = new Obstacle(width - diam - diam / 2, height / 2 - diam / 2, diam, diam);

    start = new Obstacle(diam / 2, height / 2 - diam / 2, diam, diam);

​

    // Create a population with a mutation rate, and population max

    let popmax = 500;

    let mutationRate = 0.02;

    population = new Population(mutationRate, popmax);

​

    // Create the obstacle course

    obstacles = [];

​

    // obstacles.push(new Obstacle(width/4,80,10,height-160));

    // obstacles.push(new Obstacle(width/2,0,10,height/2-20));

    // obstacles.push(new Obstacle(width/2,height-height/2+20,10,height/2-20));

    // obstacles.push(new Obstacle(2*width/3,height/2-height/8,10,height/4));

  }

​

  function draw() {

    background(210);

​

    // Draw the target positions

    target.display();

​

    // Draw the obstacles

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

      obstacles[i].display();

    }

​

​

    // If the generation hasn't ended yet

    if (lifecycle < lifetime) {

      population.live(obstacles);

      if ((population.targetReached()) && (lifecycle < recordtime)) {

        recordtime = lifecycle;

      }

      lifecycle++;

      // Otherwise a new generation

    } else {

      lifecycle = 0;

      population.calcFitness();

      population.naturalSelection();

      population.generate();

    }

​

    // Display some info

    if (newObstacle !== null) {

      newObstacle.display();

    }

​

    info.html("Generation #: " + floor(population.getGenerations()) +

      "<br/>Cycles left: " + floor(lifetime - lifecycle) +

      "<br/>Record cycles: " + floor(recordtime));

​

  }

​

  function keyPressed() {

    console.log(key);

    if (key === 'd' || key === 'D') {

      debug = !debug;

    }

  }

​

  function mousePressed() {

    newObstacle = new Obstacle(mouseX, mouseY, 0, 0);

  }

​

  function mouseDragged() {

    newObstacle.w = mouseX - newObstacle.position.x;

    newObstacle.h = mouseY - newObstacle.position.y;

​

  }

​

  function mouseReleased() {

    obstacles.push(newObstacle);

    newObstacle = null;

  }