improvements on visualizer in terms of synchronization

desktop/src/zero1hd/rhythmbullet/desktop/DesktopLauncher.java

@@ -14,8 +14,6 @@ public class DesktopLauncher {
 		config.resizable = false;
 		config.allowSoftwareMode = true;
 		config.useHDPI = true;
-		config.vSyncEnabled = false;
-		config.foregroundFPS = 0;
 		core = new RhythmBullet();
 		core.setInitialScreen(new LoadingScreen(core));
 		new LwjglApplication(core, config);

desktop/src/zero1hd/rhythmbullet/desktop/audio/Mp3Manager.java

@@ -92,8 +92,9 @@ public class Mp3Manager implements MusicManager {
 	}
 
 	@Override
-	public void playbackIndexUpdate() {
+	public int playbackIndexUpdate() {
 		playbackIndex = (int) (playbackMusic.getPosition() * sampleRate / readWindowSize);
+		return playbackIndex;
 	}
 
 	@Override

desktop/src/zero1hd/rhythmbullet/desktop/audio/WAVManager.java

@@ -47,8 +47,9 @@ public class WAVManager implements MusicManager {
 	}
 
 	@Override
-	public void playbackIndexUpdate() {
+	public int playbackIndexUpdate() {
 		playbackIndex = (int) ((getSampleRate() * getDuration())/getReadWindowSize());
+		return playbackIndex;
 	}
 
 	@Override

desktop/src/zero1hd/rhythmbullet/desktop/graphics/ui/components/Visualizer.java

@@ -29,18 +29,20 @@ public class Visualizer extends Widget implements Disposable {
 	private int sourceID;
 	private float visRefreshRate = 1f/60f;
 	private float timer;
+	private int readWindowIndex;
 	public Visualizer() {
 		vis = new BasicVisualizer();
 		
 		try {
 			Field bufferField = ClassReflection.getDeclaredField(OpenALMusic.class, "tempBuffer");
 			bufferField.setAccessible(true);
-			buffer = ((ByteBuffer) bufferField.get(null)).asShortBuffer();
+			buffer = ((ByteBuffer) bufferField.get(null)).asShortBuffer().asReadOnlyBuffer();
 		} catch (IllegalArgumentException | SecurityException | ReflectionException e) {
 			e.printStackTrace();
 			Gdx.app.debug("Visualizer reflection", "Failed attempt at retrieving tempBuffer field.");
 			Gdx.app.exit();
 		}
+		
 	}
 	
 	@Override
@@ -79,21 +81,31 @@ public class Visualizer extends Widget implements Disposable {
 	
 	public void calcPCMData() {
 		short chanVal;
-		
-		int pos = (int) ((alGetSourcef(sourceID, AL11.AL_SAMPLE_OFFSET)));
-		try {
-			buffer.position(pos);
-		} catch (IllegalArgumentException outOfBounds) {
-			System.out.println(outOfBounds);
+		if (mm.playbackIndexUpdate() != readWindowIndex) {
+			updateBufferPosition();
 		}
+		
 		for (int sid = 0; sid < vis.getAudioPCM().length && sid < buffer.remaining(); sid++) {
 			for (int channel = 0; channel < mm.getChannelCount(); channel ++) {
 				if (vis.getAudioPCM()[sid] < (chanVal = buffer.get())) {
 					vis.getAudioPCM()[sid] = chanVal;
 				}
 			}
-			vis.getAudioPCM()[sid] /= Short.MAX_VALUE+1;
+			vis.getAudioPCM()[sid] /= Short.MAX_VALUE+1f;
 		}
+		readWindowIndex++;
+	}
+	
+	private int updateBufferPosition() {
+		int pos = (int) ((alGetSourcef(sourceID, AL11.AL_SAMPLE_OFFSET))-mm.getReadWindowSize()*mm.getChannelCount());
+		try {
+			readWindowIndex = mm.getPlaybackIndexPosition();
+			buffer.position(pos);
+		} catch (IllegalArgumentException iae) {
+			buffer.position(0);
+			Gdx.app.error("BufferPosition", iae + " position was " + pos);
+		}
+		return pos;
 	}
 	
 	public void setMM(MusicManager mm) {
@@ -102,7 +114,6 @@ public class Visualizer extends Widget implements Disposable {
 			sourceIDField.setAccessible(true);
 			sourceID = (int) sourceIDField.get(mm.getMusic());
 		} catch (ReflectionException e) {
-			// TODO Auto-generated catch block
 			e.printStackTrace();
 		}
 		this.mm = mm;