android-project/src/org/libsdl/app/SDLActivity.java

package org.libsdl.app;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import javax.microedition.khronos.egl.*;

import android.app.*;
import android.content.*;
import android.view.*;
import android.os.*;
import android.util.Log;
import android.graphics.*;
import android.text.method.*;
import android.text.*;
import android.media.*;
import android.hardware.*;
import android.content.*;

import java.lang.*;


/**
    SDL Activity
*/
public class SDLActivity extends Activity {

    //Main components
    private static SDLActivity mSingleton;
    private static SDLSurface mSurface;

    //Audio
    private static AudioTrack mAudioTrack;
    private static boolean bAudioIsEnabled;

    //Sensors
    private static boolean bAccelIsEnabled;

    //feature IDs. Must match up on the C side as well.
    private static int FEATURE_AUDIO = 1;
    private static int FEATURE_ACCEL = 2;

    //Load the .so
    static {
        System.loadLibrary("SDL");
        System.loadLibrary("main");
    }

    //Setup
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        //So we can call stuff from static callbacks
        mSingleton = this;

        //Set up the surface
        mSurface = new SDLSurface(getApplication());
        setContentView(mSurface);
        SurfaceHolder holder = mSurface.getHolder();
        holder.setType(SurfaceHolder.SURFACE_TYPE_GPU);
        
    }

    //Audio
    public static boolean initAudio(){        

        //blah. Hardcoded things are bad. FIXME when we have more sound stuff
        //working properly. 
        mAudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                    11025,
                    AudioFormat.CHANNEL_CONFIGURATION_MONO,
                    AudioFormat.ENCODING_PCM_8BIT,
                    2048,
                    AudioTrack.MODE_STREAM);   
        bAudioIsEnabled = true;     
        return true;
    }

    //Accel
    public static boolean initAccel(){
        mSurface.enableSensor(Sensor.TYPE_ACCELEROMETER, true);
        bAccelIsEnabled = true;
        return true;
    }
    
    public static boolean closeAccel(){
        mSurface.enableSensor(Sensor.TYPE_ACCELEROMETER, false);
        bAccelIsEnabled = false;
        return true;
    }
    

    //Events
    protected void onPause() {
        super.onPause();
    }

    protected void onResume() {
        super.onResume();
    }

    
    //C functions we call
    public static native void nativeInit();
    public static native void nativeQuit();
    public static native void nativeSetScreenSize(int width, int height);
    public static native void onNativeKeyDown(int keycode);
    public static native void onNativeKeyUp(int keycode);
    public static native void onNativeTouch(int action, float x, 
                                            float y, float p);
    public static native void onNativeResize(int x, int y, int format);
    public static native void onNativeAccel(float x, float y, float z);


    //Java functions called from C
    private static void createGLContext(){
        mSurface.initEGL();
    }

    public static void flipBuffers(){
        mSurface.flipEGL();
    }

    public static void updateAudio(byte [] buf){
    
        if(mAudioTrack == null){
            return;
        }
        
        mAudioTrack.write(buf, 0, buf.length);
        mAudioTrack.play();
        
        Log.v("SDL","Played some audio");
    }

    public static void enableFeature(int featureid, int enabled){
         Log.v("SDL","Feature " + featureid + " = " + enabled);

        //Yuck. This is all horribly inelegent. If it gets to more than a few
        //'features' I'll rip this out and make something nicer, I promise :)
        if(featureid == FEATURE_AUDIO){
            if(enabled == 1){
                initAudio();
            }else{
                //We don't have one of these yet...
                //closeAudio(); 
            }
        }

        else if(featureid == FEATURE_ACCEL){
            if(enabled == 1){
                initAccel();
            }else{
                closeAccel();
            }
        }
    }


}

/**
    Simple nativeInit() runnable
*/
class SDLRunner implements Runnable{
    public void run(){
        //SDLActivity.initAudio();
        
        //Runs SDL_main()
        SDLActivity.nativeInit();

        Log.v("SDL","SDL thread terminated");
    }
}


/**
    SDLSurface. This is what we draw on, so we need to know when it's created
    in order to do anything useful. 

    Because of this, that's where we set up the SDL thread
*/
class SDLSurface extends SurfaceView implements SurfaceHolder.Callback, 
    View.OnKeyListener, View.OnTouchListener, SensorEventListener  {

    //This is what SDL runs in. It invokes SDL_main(), eventually
    private Thread mSDLThread;    
    
    //EGL private objects
    private EGLContext  mEGLContext;
    private EGLSurface  mEGLSurface;
    private EGLDisplay  mEGLDisplay;

    //Sensors
    private static SensorManager mSensorManager;

    //Startup    
    public SDLSurface(Context context) {
        super(context);
        getHolder().addCallback(this); 
    
        setFocusable(true);
        setFocusableInTouchMode(true);
        requestFocus();
        setOnKeyListener(this); 
        setOnTouchListener(this);   
        
        mSensorManager = (SensorManager)context.getSystemService("sensor");  
    }

    //Called when we have a valid drawing surface
    public void surfaceCreated(SurfaceHolder holder) {
        Log.v("SDL","Surface created"); 

        int width = getWidth();
        int height = getHeight();

        //Set the width and height variables in C before we start SDL so we have
        //it available on init
        SDLActivity.nativeSetScreenSize(width, height);

        //Now start up the C app thread
        mSDLThread = new Thread(new SDLRunner(), "SDLThread"); 
		mSDLThread.start();       
    }

    //Called when we lose the surface
    public void surfaceDestroyed(SurfaceHolder holder) {
        Log.v("SDL","Surface destroyed");
        
        SDLActivity.nativeQuit();

        //Now wait for the SDL thread to quit
        try{
            mSDLThread.wait();
        }catch(Exception e){
            Log.v("SDL","Problem stopping thread: " + e);
        }
    }

    //Called when the surface is resized
    public void surfaceChanged(SurfaceHolder holder, int format, 
                                int width, int height) {
        Log.v("SDL","Surface resized");
        
        SDLActivity.onNativeResize(width, height, format);
    }

    //unused
    public void onDraw(Canvas canvas) {}

    
    //EGL functions
    public boolean initEGL(){
        Log.v("SDL","Starting up");

        try{

            EGL10 egl = (EGL10)EGLContext.getEGL();

            EGLDisplay dpy = egl.eglGetDisplay(EGL10.EGL_DEFAULT_DISPLAY);

            int[] version = new int[2];
            egl.eglInitialize(dpy, version);

            int[] configSpec = {
                    //EGL10.EGL_DEPTH_SIZE,   16,
                    EGL10.EGL_NONE
            };
            EGLConfig[] configs = new EGLConfig[1];
            int[] num_config = new int[1];
            egl.eglChooseConfig(dpy, configSpec, configs, 1, num_config);
            EGLConfig config = configs[0];

            EGLContext ctx = egl.eglCreateContext(dpy, config, EGL10.EGL_NO_CONTEXT, null);

            EGLSurface surface = egl.eglCreateWindowSurface(dpy, config, this, null);

            egl.eglMakeCurrent(dpy, surface, surface, ctx);

            mEGLContext = ctx;
            mEGLDisplay = dpy;
            mEGLSurface = surface;
            
            
        }catch(Exception e){
            Log.v("SDL", e + "");
            for(StackTraceElement s : e.getStackTrace()){
                Log.v("SDL", s.toString());
            }
        }
        Log.v("SDL","Done making!");

        return true;
    }

    //EGL buffer flip
    public void flipEGL(){      
        try{
        
            EGL10 egl = (EGL10)EGLContext.getEGL();
            GL10 gl = (GL10)mEGLContext.getGL();

            egl.eglWaitNative(EGL10.EGL_NATIVE_RENDERABLE, null);

            //drawing here

            egl.eglWaitGL();

            egl.eglSwapBuffers(mEGLDisplay, mEGLSurface);

            
        }catch(Exception e){
            Log.v("SDL", "flipEGL(): " + e);

            for(StackTraceElement s : e.getStackTrace()){
                Log.v("SDL", s.toString());
            }
        }
    }


    //Key events
    public boolean onKey(View  v, int keyCode, KeyEvent event){

        if(event.getAction() == KeyEvent.ACTION_DOWN){
            SDLActivity.onNativeKeyDown(keyCode);
            return true;
        }
        
        else if(event.getAction() == KeyEvent.ACTION_UP){
            SDLActivity.onNativeKeyUp(keyCode);
            return true;
        }
        
        return false;
    }

    //Touch events
    public boolean onTouch(View v, MotionEvent event){
    
        int action = event.getAction();
        float x = event.getX();
        float y = event.getY();
        float p = event.getPressure();

        //TODO: Anything else we need to pass?        
        SDLActivity.onNativeTouch(action, x, y, p);
        return true;
    }

    //Sensor events
    public void enableSensor(int sensortype, boolean enabled){
        //TODO: This uses getDefaultSensor - what if we have >1 accels?
        if(enabled){
            mSensorManager.registerListener(this, 
                            mSensorManager.getDefaultSensor(sensortype), 
                            SensorManager.SENSOR_DELAY_GAME, null);
        }else{
            mSensorManager.unregisterListener(this, 
                            mSensorManager.getDefaultSensor(sensortype));
        }
    }
    
    public void onAccuracyChanged(Sensor sensor, int accuracy){
        //TODO
    }

    public void onSensorChanged(SensorEvent event){
        if(event.sensor.getType() == Sensor.TYPE_ACCELEROMETER){
            SDLActivity.onNativeAccel(  event.values[0],
                                        event.values[1],
                                        event.values[2] );
        }
    }


}