This week we carried on our “Shootah” space shooting game  by adding some bullets with an appropriate sound effect.  This brings the game to the stage shown below:

Not very snazzy but it’s starting to show some promise!

As with last week, this will only run if served up from a web server, we had a few ninjas in that missed last week and had to install node.js and local-web-server application.

Bullets!

Our Bullets were a pretty simple object that just moves up constantly – this has the following code:

class Bullet {
    constructor(x, y){
        this.x = x;
        this.y = y;        
        this.speed = 10;
    }

    move(){
        this.y = this.y - this.speed;
    }

    show(){
        push();
        fill("yellow");
        ellipse(this.x, this.y, 10, 10);
        pop();
    }
}

function preload(){
   playerImage = loadImage("images/spaceship.png");
   bulletSound = loadSound("sound/laser.mp3");
}

function draw() {
  // .... skipping a few lines
  for(let i=0; i< bullets.length; i++){
     bullets[i].move();
     bullets[i].show();
  }
  // .... skipping a few lines
}

function keyPressed(){
   if(keyCode==UP_ARROW){
   bullets.push(new Bullet(player.x, player.y));
   bulletSound.play();
 }
}

The sound was done very similarly to the image – we created a folder (sound) and added a sound file we found on the internet to the folder.  In the preload function we loaded the sound from the file into a variable (“bulletSound”).  In the keyPressed function, we check if the pressed key is UP ARROW and if so, we play the sound and add a new bullet to the list.. voila!

Problems to work on!

A great start but a lot left to be sorted with this game!  Here are some of the items:

• The bullets array grows forever – this really starts to slow down the game as we keep playing it.  We need to add some code to remove a bullet from the array when it is gone off the screen.
• The player has no edge detection – we need some way to keep it onscreen.
• We need some enemies!!
• We need to get the bullets to check when they are hitting the enemies!
• We need to keep and display a score
• We need a way to die.. perhaps the enemies can drop bombs?
• Other ideas:
  • Maybe a background tune in a loop?
  • Maybe a scrolling starfield in the background?
  • Maybe multiple levels?
  • Maybe different types of enemies?
  • Maybe a shield?
  • Perhaps some different weapons or weapons you can pick up?

We have gotten this far so we might as well push forward and make this a fully working game so we’ll get some of the above sorted next week!  The code is as usual up on our github.  https://github.com/coderdojoathenry/creators2018