// http://codingtra.in

// http://patreon.com/codingtrain

// Code for this video: https://youtu.be/BAejnwN4Ccw

​

var cities = [];

var totalCities = 5;

​

var recordDistance;

var bestEver;

​

function setup() {

  createCanvas(400, 300);

  for (var i = 0; i < totalCities; i++) {

    var v = createVector(random(width), random(height));

    cities[i] = v;

  }

​

  var d = calcDistance(cities);

  recordDistance = d;

  bestEver = cities.slice();

​

}

​

function draw() {

  background(0);

  fill(255);

  for (var i = 0; i < cities.length; i++) {

    ellipse(cities[i].x, cities[i].y, 8, 8);

  }

​

  stroke(255);

  strokeWeight(1);

  noFill();

  beginShape();

  for (var i = 0; i < cities.length; i++) {

    vertex(cities[i].x, cities[i].y);

  }

  endShape();

​

  stroke(255, 0, 255);

  strokeWeight(4);

  noFill();

  beginShape();

  for (var i = 0; i < cities.length; i++) {

    vertex(bestEver[i].x, bestEver[i].y);

  }

  endShape();

​

​

​

  var i = floor(random(cities.length));

  var j = floor(random(cities.length));

  swap(cities, i, j);

​

  var d = calcDistance(cities);

  if (d < recordDistance) {

    recordDistance = d;

    bestEver = cities.slice();

  }

}

​

function swap(a, i, j) {

  var temp = a[i];

  a[i] = a[j];

  a[j] = temp;

}

​

​

function calcDistance(points) {

  var sum = 0;

  for (var i = 0; i < points.length - 1; i++) {

    var d = dist(points[i].x, points[i].y, points[i + 1].x, points[i + 1].y);

    sum += d;

  }

  return sum;

}