text: const Engine = Matter.Engine;
  const World = Matter.World;
  const Bodies = Matter.Bodies;
  const Constraint = Matter.Constraint;
  var engine, world, backgroundImg, waterSound, backgroundMusic, cannonExplosion;
  var canvas, angle, tower, ground, cannon, boat;
  var balls = [];
  var boats = [];
  var brokenBoatanimation= [];
  var brokenBoatSpritedata;
  var brokenBoatSpritesheet;
  var boatAnimation = [];
  var boatSpritedata, boatSpritesheet;
  
  
  
  function preload() {
    backgroundImg = loadImage("./assets/background.gif");
    towerImage = loadImage("./assets/tower.png");
    boatSpritedata = loadJSON("assets/boat/boat.json");
    boatSpritesheet = loadImage("assets/boat/boat.png");
    brokenBoatSpritedata = loadJSON("assets/boat/broken_boat.json");
    brokenBoatSpritesheet = loadImage("assets/boat/broken_boat.png");
  
  }
  
  function setup() {
    canvas = createCanvas(1200, 600);
    engine = Engine.create();
    world = engine.world;
    angle = -PI / 4;
    ground = new Ground(0, height - 1, width * 2, 1);
    tower = new Tower(150, 350, 160, 310);
    cannon = new Cannon(180, 110, 110, 50, angle);
  
    var boatFrames = boatSpritedata.frames;
    for (var i = 0; i < boatFrames.length; i++) {
      var pos = boatFrames[i].position;
      var img = boatSpritesheet.get(pos.x, pos.y, pos.w, pos.h);
      boatAnimation.push(img);
    }
    var brokenBoatFrames = brokenBoatSpritedata.frames;
    for(var j = 0; j < brokenBoatFrames.length; j++){
      var pos = brokenBoatFrames[j].position;
      var img = brokenBoatSpritesheet.get(pos.x,pos.y,pos.w,pos.h)
      brokenBoatanimation.push(img);
    }
  
  
  }
  
  function draw() {
    background(189);
    image(backgroundImg, 0, 0, width, height);
  
  
    Engine.update(engine);
    ground.display();
  
    showBoats();
  
    for (var i = 0; i < balls.length; i++) {
      showCannonBalls(balls[i], i);
      for (var j = 0; j < boats.length; j++) {
        if (balls[i] !== undefined && boats[j] !== undefined) {
          var collision = Matter.SAT.collides(balls[i].body, boats[j].body);
          if (collision.collided) {
            boats[j].remove(j);
  
            Matter.World.remove(world, balls[i].body);
            balls.splice(i, 1);
            i--;
          
          }
        }
      }
    }
  
    cannon.display();
    tower.display();
  
  
  }
  
  
  //creating the cannon ball on key press
  function keyPressed() {
    if (keyCode === DOWN_ARROW) {
      var cannonBall = new CannonBall(cannon.x, cannon.y);
      cannonBall.trajectory = [];
      Matter.Body.setAngle(cannonBall.body, cannon.angle);
      balls.push(cannonBall);
    }
  }
  
  // function to show the ball.
  function showCannonBalls(ball, index) {
    ball.display();
    if (ball.body.position.x >= width || ball.body.position.y >= height - 50) {
      Matter.World.remove(world, ball.body);
      balls.splice(index, 1);
    }
  }
  
  
  //function to show the boat
  function showBoats() {
    if (boats.length > 0) {
      if (
        boats.length < 4 &&
        boats[boats.length - 1].body.position.x < width - 300
      ) {
        var positions = [-40, -60, -70, -20];
        var position = random(positions);
        var boat = new Boat(
          width,
          height - 100,
          170,
          170,
          position,
          boatAnimation
        );
  
        boats.push(boat);
      }
  
      for (var i = 0; i < boats.length; i++) {
        Matter.Body.setVelocity(boats[i].body, {
          x: -0.9,
          y: 0
        });
  
        boats[i].display();
        boats[i].animate();
        var collision = Matter.SAT.collides(tower.body, boats[i].body);
  
      }
    } else {
      var boat = new Boat(width, height - 60, 170, 170, -60, boatAnimation);
      boats.push(boat);
    }
  }
  
  
  //releasing the cannonball on key release
  function keyReleased() {
    if (keyCode === DOWN_ARROW) {
      balls[balls.length - 1].shoot();
    }
  }
  