Full Game Tutorial - part 2 - creating Activity:

In the previous article, we successfully downloaded the engine, and physics extension, we also created our game project, linked the engine sources, and created a new blank class for our activity, in this article we will set-up this activity.

We will use only one activity, and multiple scenes, here`s little diagram showing our scenes:

After opening our game, the following order will be used:

1. load splash texture, create splash screen, display splash scene.
2. while displaying splash, load menu resources, and create menu scene(s).
3. menu has been loaded, unload splash screen, display main menu scene.
4. user can switch between main menu scene and sub-scene (ex. options)
5. while switching to the game play scene, a loading scene will be displayed first, unloading menu textures, loading game resources and creating the game scene.
6. user can switch back from the game to the menu scene, the loading scene will be displayed while unloading game resources, destroying the game scene and loading back menu textures.

So as you can see, its pretty easy, nothing too complicated. Please note it is my way of handling it. It's up to you to modify it to suit your needs, depending on your game complexity for most games it should be good enough.

1. Setting up Game Activity:

package com.matimdev;

import java.io.IOException;

import org.andengine.engine.options.EngineOptions;
import org.andengine.entity.scene.Scene;
import org.andengine.ui.activity.BaseGameActivity;

/**
 * @author Mateusz Mysliwiec
 * @author www.matim-dev.com
 * @version 1.0
 */
public class GameActivity extends BaseGameActivity
{
    public EngineOptions onCreateEngineOptions()
    {
        return null;
    }

    public void onCreateResources(OnCreateResourcesCallback pOnCreateResourcesCallback) throws IOException
    {
        
    }

    public void onCreateScene(OnCreateSceneCallback pOnCreateSceneCallback) throws IOException
    {
        
    }

    public void onPopulateScene(Scene pScene, OnPopulateSceneCallback pOnPopulateSceneCallback) throws IOException
    {
        
    }
}

@Override
public Engine onCreateEngine(EngineOptions pEngineOptions) 
{
    return new LimitedFPSEngine(pEngineOptions, 60);
}

private Camera camera;
    
public EngineOptions onCreateEngineOptions()
{
    camera = new Camera(0, 0, 800, 480);
    EngineOptions engineOptions = new EngineOptions(true, ScreenOrientation.LANDSCAPE_FIXED, new RatioResolutionPolicy(800, 480), this.camera);
    engineOptions.getAudioOptions().setNeedsMusic(true).setNeedsSound(true);
    engineOptions.setWakeLockOptions(WakeLockOptions.SCREEN_ON);
    return engineOptions;
}

We've created a new camera, sized 800 x 480 pixels (it is up to you to decide what screen resolution you are going to tackle, this is currently most frequently used one) next we created our engine options, setting the full screen parameter to true, using fixed landscape orientation, and ratio resolution policy (if the game will be used on a different screen resolution the engine will resize our game, while keeping the proper ratio) we also set needs music and sound to true, so we will be able to use some audio for our game.

2. Editing android manifest file:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.matimdev"
    android:versionCode="1"
    android:versionName="1.0">

    <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="15" />
    
	<uses-permission android:name="android.permission.WAKE_LOCK" />
	<uses-permission android:name="android.permission.VIBRATE"/>
	<uses-permission android:name="android.permission.INTERNET"/>
	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
	<uses-permission android:name="android.permission.READ_PHONE_STATE" />

    <application
        
        android:label="@string/app_name"
        android:icon="@drawable/ic_launcher"
        android:theme="@style/AppTheme">
        
        <activity
            android:name=".GameActivity"
            android:label="@string/app_name"
			android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize|mcc|mnc"
            android:screenOrientation="landscape">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>

</manifest>

We are enabling the most important permissions, such as internet access. (Used if you would like to include advertisements in your app etc) we also provided information about our activity. We also included configChanges property.

Check out the next article, where I will introduce the scene manager and scene management system.