In the Advanced AndEngine Examples - Render Texture and Fragment Shaders tutorial I've shown you how to use render texture and shaders to create some cool effects in AndEngine. At first nobody really wanted the source code but now I got a few requests, so here they are.

I should probably create a GitHub repository for all the examples I have created :)

FIFA World Cup 2014 in Brazil is one of the major holidays this year. The game developers couldn't stay behind and even though I am just a small fish, I am getting football and soccer related games to review, too.

I wrote about one football game before. It is called Nation Soccer and its source code is available as well. One of the submitted games is basically a highly polished variant of this game. It might be worth checking the source code out!

Anyway, here are the games submitted before the event starts in Brazil.

Miniball Tap Football by Naked Penguin Boy UK

A simple reaction/puzzle game that I have seen before, but the football theme suits it quite well. A good timewaster, but it got low ratings. Probably the levels get too repetitive after a while. 



Google Play Store

Puppet Soccer 2014 - Football by NOXGAMES

This game is the one similar to Nation Soccer. The original game was fun and this one brings a lot of new elements. The game even has real footballers drawn as caricatures, really cute. The only thing missing is Brazuca! Well played with the keywords in the title.



Google Play store

Super pocket football by Inlogic Games

Finally a football game, when you actually play football :) It is 2.5D and it reminds me of games I used to play when I was little. The game play can't match games like FIFA 14, but not bad for a change.



Google Play store


 

Due to my demanding full-time job and a few part-time activities such as writing a book about AndEngine (it has been published!), I must take a break from writing the tutorial. The game is complete and I actually published it. You can find it in Google Play store.

If you have followed the tutorial and would like to see how the final code looks like, you can. I am offerring the source code for download for 99¢ (that is about $1 :)).

Features

A lot of important features of AndEngine were used. The list includes but is not limited to:

• Resource Management, loading and unloading of resources
• Scene management - Splash, Menu, Loading, Game and Ad Scene. The Loading scene is animated, using asynchronous task
• Sprites, tiled sprites and simple animations. Entity factories.
• Physics, bodies with multiple fixtures, collisions with filtering. Mouse joint.
• Music, sounds.

Flappy Bird definitely had an impact on indie game scene. It seems that everyone should create at least one Flappy Bird clone. As a person who reviews games, I've seen about 20 flappy bird clones and I am sure that was just a fraction of all the flappy animals on the market.

Creating a similar game is actually very simple. You can make the whole thing in a matter of hours. I've re-used assets from my previous game Mr. Dandelion's Adventures and I've used AndEngine GLES2-Anchorcenter to create it. I've also used Box2D (the AndEngine's extension), but it was a bit overkill. Nevertheless using Box2D probably saved some time. It was a pleasant programming excercise!

If you like learning by example, here's a list of lists of open source games for Android.

F-Droid - a very large list of open source Android apps and games. They also have their own app that simplifies installation of FOSS (free and open source software). List of games is here.
Wikipedia - you can find everything on Wikipedia. 
Another smaller list of games
A blog entry with 15 open source games

Don't forget to check the licensing of the source codes before you start using them ;)

This article will give you a simple tip how to backup your codes in a cloud and use version control at the same time and completely for free. This option uses Git that is included in Eclipse bundled with Android Development Tools and Dropbox.

Code backup

You are probably doing this already. One of the possibilities is to use a cloud storage service. You can use Google Drive or Dropbox, which is my favourite. If you don't have a Dropbox account, get one (this is a referral link. If you use it, we both get extra 500MB of space to use) and install Dropbox.

You can simply put your workspace or your project directory inside Dropbox (symbolic links work too).  Each change is automatically synced with Dropbox server. As a bonus you have your codes available from anywhere.

First I have to warn you, the articles in the Advanced AndEngine Examples series are not step-by-step tutorials for beginners. These articles are meant for more advanced AndEngine users who already know how to use AndEngine.

AndEngine has a lot of advanced features. The more advanced something gets, the less tutorials there are and even less practical examples. Today I am going to show you two features that not many people know about and even less people use: rendering to a texture and fragment shaders.

This part will show you how to load assets to memory and how to use them in a scene.

It's important to preload some resources, especially those that will be used all the time, but you can't load too many resources at once simply because you might run out of memory and the gamers could run out of patience waiting for everything to load. It is equally important to unload those resources that are no longer needed.

For the purpose of preloading resources a splash screen is usually displayed first. It is not necessary, but first you can show your brand or name and second it will give users something to look at while you are loading the resources in the background. You can also show some kind of progress bar, but splash works just fine.

I've participated in Game Jam organized by Game Developement at Stack Exchange.

A game jam is a gathering of game developers for the purpose of planning, designing, and creating one or more games within a short span of time, usually ranging between 24 to 48 hours. Game developers are generally made up of programmers, game designers, artists, and others in game development-related fields. (Wikipedia)

The great thing about Game Jam is that it forces you to think and code quickly. The requirement was to make a game playable in browser. I was thinking of using libgdx, but ended up using Phaser, a Javascript/Typescript framework. It was a great learning experience.

I call the game TCOB1. Theme was "There can only be one" (sic) and the genre of my game ended up being "endless" space racing where players are eliminated by asteroids. The last player in the game wins.

It took me about 8 hours to finish the first prototype and another 8 hours to complete the game. Phaser development is really fast. My next step will be to get better in Javascript and make the game more portable - I want it to be playable in Android stock browser and mobile Chrome.

You can play the game in your browser. Instructions are on the page itself. Source code is available if you want to take a look. The Javascript code is not so nice - but not that bad considering I started learning Javascript on Friday night and submitted the game on Sunday night!

Simple screenshot from the game

In the third part we have created an empty activity. We have set the engine to show "null" as our scene in onCreateScene method. If you check the examples, there is always a real scene created in this method. But we want to have multiple scenes and therefore we need a mechanism how to switch between them.

Also we will need a mechanism to pass important objects to each scene. We can do it when constructing scenes. Or we can use another class called ResourceManager.

Resource manager

This class will be used for our resources like textures, sounds and music. Because all of our scenes will be using it extensively, we will also put some important objects there. Loading the textures etc will be described in the next parts, I will be adding them as they will be needed. For now, create a really simple Resource Manager that looks like this:

package is.kul.squongtutorial.resources;

import is.kul.squongtutorial.GameActivity;

import org.andengine.engine.Engine;
import org.andengine.engine.camera.Camera;
import org.andengine.opengl.vbo.VertexBufferObjectManager;

public class ResourceManager {
  private static final ResourceManager INSTANCE = new ResourceManager();
  
  //common objects
  public GameActivity activity;
  public Engine engine;
  public Camera camera;
  public VertexBufferObjectManager vbom;
  
  private ResourceManager() {}
  
  public static ResourceManager getInstance() {
    return INSTANCE;
  }
  
  public void init(GameActivity activity) {
    this.activity = activity;
    this.engine = activity.getEngine();
    this.camera = engine.getCamera();
    this.vbom = engine.getVertexBufferObjectManager();
  }
}

Update the GameActivity to instantiate the ResourceManager:

  @Override
  public void onCreateResources(
      OnCreateResourcesCallback pOnCreateResourcesCallback)
      throws IOException {
    ResourceManager.getInstance().init(this);
    pOnCreateResourcesCallback.onCreateResourcesFinished();
  }

This class follows what we call Singleton pattern. It means there can be only one instance in the whole program. That's why there is the private constructor, nobody else can create a new instance. It is important to have only single resource manager because due to the limitations of the hardware, you really want to keep only one instance of assets in memory.

For now, we will only use it to have a simple reference to activity, engine, camera and vertex buffer object manager.

Vertex Buffer Object is part of OpenGL. It provides methods to render vertex data. AndEngine does great job of hiding this from you. Simply use the VBO Manager all the time, at least for your first game.

Scene is basically a set of entities that are being currently displayed. You typically want to have completely different entities in menu and in the game. And that's why you create menu scene and game scene.

Android platform suffers from variety of different screen sizes and ratios. AndEngine tries to deal with this by letting you specify one resolution and then scaling the resulting picture to any device.

You don't need to care whether the screen size of the phone is bigger than your desired resolution  (AndEngine can enlarge your scene) or smaller (AndEngine can shrink your scene). You place your sprites at coordinates in your resolution. However you still have to hint AndEngine how should the resulting picture be scaled (if at all). And that's what Resolution Policy is for.

You might want to have multiple sets of textures for let's say two or three typical resolutions. For example low-res, normal and HD textures. But that is a more advanced topic.

My first app (as in "not a game") that will be soon published to the Google Play Store. A simple tool to toggle auto-rotate screen and in case the screen is locked, shake to rotate the screen to desired orientation.

I created the app to learn more about programming for Android. My intention was to learn about the accelerometer, notofications and background services and this is an app that combines all three.


It's still in beta test phase but if you want, you can help testing it.