Android Game Development

1. Android Game Development Androidbasics

2. AboutAndroid • Linux based operating system • Open source • Designed for handheld devices • Developed by • Android Inc. • Google (2005) • Open HandsetAlliance (2007) • Very successful system (75% sales in 2012)

3. Top mobile operating systems

4. Android basics • Can run Java code on Dalvik VM • Multi-user system (each application is a different user) • Unique user ID • Has its own virtual machine • Has its own Linux process • Principle of least privilege • Applications can share data

5. Application components • Building blocks of an application • 4 types • Activity • Single screen with UI • Service • Backgroud process without UI • Content provider • Manages a shared set of application data • Broadcast receiver • Responds to system-wide broadcast announcements

6. Applications • All components of an application runs in the same process • The system tries to keep a process as long as possible • Applications are stored in a stack • The systems duty to destroy the applications • The system uses importance hierarchy • Foreground processes • Visible process • Service process • Background process • Empty process

7. Activitylifecycle

8. Androiddevelopment • Andriod SDK (http://developer.android.com/sdk) • Java API libraries for different platforms • SDK manager • AVD Manager (emulator) • Developer IDE • Eclipse with ADT (Juno has it by default) • Netbeans with NBAndroidplugin • Android device • USB Driver • Enable USB debugging • Useful link: http://developer.android.com

9. IDE basics • NetBeans • https://kenai.com/projects/nbandroid/pages/Install • https://kenai.com/projects/nbandroid/pages/Intro • Eclipse • For ADT bundle everything is set up • http://developer.android.com/sdk/installing/bundle.html • For Juno install is not required, for other existing Eclipse installs: • http://developer.android.com/sdk/installing/adding-packages.html • Add platforms and packages • http://developer.android.com/sdk/installing/adding-packages.html

10. Set up virtual devices

11. Set up virtual devices Presets

12. API levels

13. API levels

14. New Project (NetBeans)

15. New Project

16. New Project

17. AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="gamedev.android.UEngine.PlatformGame" android:versionCode="1" android:versionName="1.0"> <application android:label="@string/app_name" > <activity android:name="MainActivity" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest> Our application version Activity to start Icon label of our Activity We can change this to e.g.: “MyPlatformGame”

18. Start a virtual device

19. Build and run the project MainActivity.java: setContentView(R.layout.main); Main.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Hello World, MainActivity" /> </LinearLayout>

20. OpenGL ES – MainActivity.java import android.app.Activity; import android.opengl.GLSurfaceView; import android.os.Bundle; public class MainActivity extends Activity { private GLSurfaceViewmGLView; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mGLView = new MainSurfaceView(this); setContentView(mGLView); } }

21. OpenGL ES – MainSurfaceView.java package gamedev.android.UEngine.PlatformGame; import android.content.Context; import android.opengl.GLSurfaceView; public class MainSurfaceView extends GLSurfaceView { private MainRenderermRenderer; public MainSurfaceView(Context context) { super(context); this.mRenderer = new MainRenderer(getContext()); setRenderer(this.mRenderer); } }

22. OpenGLES – MainRenderer.java package gamedev.android.UEngine.PlatformGame; import android.content.Context; import android.opengl.GLSurfaceView; import javax.microedition.khronos.egl.EGLConfig; import javax.microedition.khronos.opengles.GL10; public class MainRenderer implements GLSurfaceView.Renderer{ private Context context; public MainRenderer(Context context) { this.context = context; } public void onSurfaceCreated(GL10 gl, EGLConfigconfig) { gl.glClearColor(0.5F, 0.5F, 1.0F, 1.0F); } public void onDrawFrame(GL10 gl) { gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT ); } public void onSurfaceChanged(GL10 gl, int width, int height) { gl.glViewport(0, 0, width, height); } }

23. Build and run

24. Draw something - MainRenderer • New imports import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.nio.FloatBuffer; • New data member protected FloatBuffer VB = null; public float rotAngle = 0;

25. Draw something - MainRenderer public void onSurfaceCreated(GL10 gl, EGLConfigconfig) { gl.glClearColor(0.5F, 0.5F, 1.0F, 1.0F); float[] VCoords = { -1.0F, -1.0F, 0.0F, 1.0F, -1.0F, 0.0F, 1.0F, 1.0F, 0.0F, -1.0F, -1.0F, 0.0F, 1.0F, 1.0F, 0.0F, -1.0F, 1.0F, 0.0F }; ByteBuffervbb = ByteBuffer.allocateDirect(VCoords.length * 4); vbb.order(ByteOrder.nativeOrder()); this.VB = vbb.asFloatBuffer(); this.VB.put(VCoords); this.VB.position(0); }

26. Draw something - MainRenderer public void onDrawFrame(GL10 gl) { gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT ); gl.glMatrixMode(gl.GL_MODELVIEW); gl.glLoadIdentity(); gl.glTranslatef(0,0,-6); gl.glColor4f(1, 0, 0, 1); gl.glRotatef(rotAngle, 0, 1, 0); gl.glEnableClientState(gl.GL_VERTEX_ARRAY); gl.glVertexPointer(3, gl.GL_FLOAT, 0, this.VB); gl.glDrawArrays(gl.GL_TRIANGLES, 0, 6); gl.glDisableClientState(gl.GL_VERTEX_ARRAY); rotAngle += 2.5f; }

27. Draw something - MainRenderer public void onSurfaceChanged(GL10 gl, int width, int height) { gl.glViewport(0, 0, width, height); float ratio = (float) width / height; gl.glMatrixMode(gl.GL_PROJECTION); gl.glLoadIdentity(); gl.glFrustumf(-ratio, ratio, -1, 1, 1.0f, 10); }

28. Build and run

29. Input handling - MainSurfaceView protected float lastX = -1; public booleanonTouchEvent(MotionEvent e) { float x = e.getX(); switch (e.getAction()) { case MotionEvent.ACTION_MOVE: float dx = lastX == -1 ? 0 : x - lastX; mRenderer.rotAngle += dx * 1.0f; break; } lastX = x; return true; } Also remove rotAngle += 2.5f; from MainRenderer.onDrawFrame

30. Build and run • Quad can be rotated with the mouse in emulator

31. Orientation – Full screen • Fix orientation to landscape (typical in games) Activity::onCreate(): setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); • Set to full screen (typical in games) Activity::onCreate(): requestWindowFeature(Window.FEATURE_NO_TITLE); getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); • Rotate emulator to landscape mode: Ctrl+F12

32. Compile and run

33. The End