added example sounds for JNI calls

proj.android-studio/app/src/main/java/fishrungames/doublehitballs/GL2JNIActivity.java

@@ -21,6 +21,8 @@ import android.view.MotionEvent;
 public class GL2JNIActivity extends Activity
 {
 
+	private static GL2JNIActivity instance;
+	
 	GLView mView;
 	
 	@Override
@@ -29,6 +31,8 @@ public class GL2JNIActivity extends Activity
 		
 		super.onCreate(icicle);
 
+		instance = this;
+
 		EngineWrapper.LoadSalmonEngineLibrary();
 		EngineWrapper.SetActivityInstance(this);
 		EngineWrapper.SetupEnviroment();
@@ -88,4 +92,9 @@ public class GL2JNIActivity extends Activity
 		EngineWrapper.ProcessKeyDown(keyCode, event);
 		return super.onKeyDown(keyCode, event);
 	}
+
+	public static GL2JNIActivity getInstance() {
+		return instance;
+	}
+
 }

proj.android-studio/app/src/main/java/fishrungames/doublehitballs/sounds/JniSoundCalls.java

@@ -0,0 +1,11 @@
+package fishrungames.doublehitballs.sounds;
+
+public interface JniSoundCalls {
+
+    void playBackgroundSound();
+    void stopBackgroundSound();
+
+    void playGunshotSound();
+    void stopGunshotSound();
+
+}

proj.android-studio/app/src/main/java/fishrungames/doublehitballs/sounds/JniSoundCallsImpl.java

@@ -0,0 +1,47 @@
+package fishrungames.doublehitballs.sounds;
+
+import android.media.MediaPlayer;
+
+import fishrungames.doublehitballs.GL2JNIActivity;
+import fishrungames.doublehitballs.R;
+
+/**
+ * example sounds for JNI calls
+ * @author Artem Budarin
+ * Created by Artem Budarin on 06.08.2018.
+ */
+
+public class JniSoundCallsImpl implements JniSoundCalls {
+
+    private MediaPlayer backgroundPlayer = null;
+    private MediaPlayer gunshotPlayer = null;
+
+    @Override
+    public void playBackgroundSound() {
+        backgroundPlayer = MediaPlayer.create(GL2JNIActivity.getInstance(), R.raw.background_sound);
+        backgroundPlayer.setLooping(true);
+        backgroundPlayer.start();
+    }
+
+    @Override
+    public void stopBackgroundSound() {
+        if (backgroundPlayer != null) {
+            backgroundPlayer.stop();
+        }
+    }
+
+    @Override
+    public void playGunshotSound() {
+        gunshotPlayer = MediaPlayer.create(GL2JNIActivity.getInstance(), R.raw.gunshot_sound);
+        gunshotPlayer.setLooping(false);
+        gunshotPlayer.start();
+    }
+
+    @Override
+    public void stopGunshotSound() {
+        if (gunshotPlayer != null) {
+            gunshotPlayer.stop();
+        }
+    }
+
+}