content: /*******************************************************************************
   * Copyright 2011 See AUTHORS file.
   * 
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   * 
   *   http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   ******************************************************************************/
  package com.badlogic.gdx.backends.android;
  
  import android.media.AudioFormat;
  import android.media.AudioManager;
  import android.media.AudioTrack;
  
  import com.badlogic.gdx.audio.AudioDevice;
  
  /**
   * Implementation of the {@link AudioDevice} interface for Android using the AudioTrack class. You will need to set the permission
   * android.permission.RECORD_AUDIO in your manifest file.
   * @author mzechner
   * 
   */
  class AndroidAudioDevice implements AudioDevice {
  	/** the audio track **/
  	private final AudioTrack track;
  
  	/** the mighty buffer **/
  	private short[] buffer = new short[1024];
  
  	/** whether this device is in mono or stereo mode **/
  	private final boolean isMono;
  	
  	/** the latency in samples **/
  	private final int latency;
  
  	AndroidAudioDevice (int samplingRate, boolean isMono) {
  		this.isMono = isMono;
  		int minSize = AudioTrack.getMinBufferSize(samplingRate, isMono ? AudioFormat.CHANNEL_CONFIGURATION_MONO
  			: AudioFormat.CHANNEL_CONFIGURATION_STEREO, AudioFormat.ENCODING_PCM_16BIT);
  		track = new AudioTrack(AudioManager.STREAM_MUSIC, samplingRate, isMono ? AudioFormat.CHANNEL_CONFIGURATION_MONO
  			: AudioFormat.CHANNEL_CONFIGURATION_STEREO, AudioFormat.ENCODING_PCM_16BIT, minSize, AudioTrack.MODE_STREAM);
  		track.play();
  		latency = minSize / (isMono?1:2);
  	}
  
  	@Override public void dispose () {
  		track.stop();
  		track.release();
  	}
  
  	@Override public boolean isMono () {
  		return isMono;
  	}
  
  	@Override public void writeSamples (short[] samples, int offset, int numSamples) {
  		int writtenSamples = track.write(samples, offset, numSamples);
  		while (writtenSamples != numSamples)
  			writtenSamples += track.write(samples, offset + writtenSamples, numSamples - writtenSamples);
  	}
  
  	@Override public void writeSamples (float[] samples, int offset, int numSamples) {
  		if (buffer.length < samples.length) buffer = new short[samples.length];
  
  		int bound = offset + numSamples;
  		for (int i = offset, j = 0; i < bound; i++, j++) {
  			float fValue = samples[i];
  			if (fValue > 1) fValue = 1;
  			if (fValue < -1) fValue = -1;
  			short value = (short)(fValue * Short.MAX_VALUE);
  			buffer[j] = value;
  		}
  
  		int writtenSamples = track.write(buffer, 0, numSamples);
  		while (writtenSamples != numSamples)
  			writtenSamples += track.write(buffer, writtenSamples, numSamples - writtenSamples);
  	}
  
  	@Override public int getLatency () {
  		return latency;
  	}
  }
  