text: const Engine = Matter.Engine;
  const World = Matter.World;
  const Bodies = Matter.Bodies;
  const Constraint = Matter.Constraint;
  
  var engine, world, backgroundImg;
  var canvas, angle, tower, ground, cannon;
  var cannonBall;
  var balls = [];
  
  function preload() {
    backgroundImg = loadImage("./assets/background.gif");
    towerImage = loadImage("./assets/tower.png");
  }
  
  function setup() {
    canvas = createCanvas(1200, 600);
    engine = Engine.create();
    world = engine.world;
  
    angleMode(DEGREES);
    angle = 15;
  
    ground = Bodies.rectangle(0, height - 1, width * 2, 1, { isStatic: true });
    World.add(world, ground);
  
    tower = Bodies.rectangle(160, 350, 160, 310, { isStatic: true });
    World.add(world, tower);
    cannon = new Cannon(180, 110, 130, 100, angle);
    // cannonBall = new CannonBall(cannon.x, cannon.y);
  }
  
  function draw() {
    background(189);
    image(backgroundImg, 0, 0, width, height);
  
    Engine.update(engine);
  }
  
  push();
  fill("brown");
  rectMode(CENTER);
  rect(ground.position.x, ground.position.y, width * 2, 1);
  pop();
  
  push();
  imageMode(CENTER);
  image(towerImage, tower.position.x, tower.position.y, 160, 310);
  pop();
  
  cannon.display();
  // cannonBall.display();
  for (var i = 0; i < ball.lenght; i++) {
    showCannonBalls(balls[i][i])
  }
  
  
  function keyPressed() {
    if (keyCode === DOWN_ARROW) {
      var cannonBall = new CannonBall(cannon.x, cannon.y);
      balls.push(cannonBalls);
    }
  
  }
  function showCannonball() {
    if (balls) {
      balls.display();
    }
  }