class Laser {

  constructor() {

    // Laser originates from the player

    this.playerPos = player.getPlayerPos();

    // Laser has a random direction and travels in a straight path in that direction

    this.angle = random(0, 360);

    // to track the position of the laser

    this.pos = createVector(this.playerPos.x, this.playerPos.y);

    // speed of the laser

    this.speed = 3;

    // size of the laser

    this.radius = 10

    // sturdiness defines how strong the laser is. If 0, the laser disappears

    this.sturdiness = laserSturdiness;

  }

  // Laser starts from the player position and the laser is just a circle

  show() {

    stroke(255);

    strokeWeight(2);

    fill("black");

    circle(this.pos.x, this.pos.y, this.radius);

  }

  // Laser moves in a straight line defined by the angle

  move() {

    angleMode(DEGREES);

    // calculating the vector of movement

    this.pos.x += this.speed * cos(this.angle);

    this.pos.y += this.speed * sin(this.angle);

  }

  // Getter function for laser position.

  getLaserPos() {

    return this.pos;

  }

}

​

// Upgrading the weapon as the game progresses

function upgrade_weapons() {

  // this will increase the number of lasers the player can shoot as time passes.

  if (laserCount != 20) {

    laserCount -= 10;

  }

  // Sturdiness of the laser is increased with certain interval, such that the laser will pierce through more aliens

  laserSturdiness++;

  // a flag so that this function is only called once every few seconds

  upgrade_flipper = false;

}

​

// This function was added because the game started lagging when it went on for a longer period of time.

// It basically deletes all the lasers that are outside the canvas

function delete_lasers_outside() {

  // checking for every laser if they are outside the canvas.

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

    if (lasers[i].pos.x < 0 || lasers[i].pos.x > width || lasers[i].pos.y < 0 || lasers[i].pos.y > height) {

      // removing the laser from the global lasers array is the same as deleting the laser.

      lasers.splice(i, 1);

    }

  }

}