multiple sounds in openal - Java-Gaming.org

just a question i'm messing around with the space invaders demo, trying to understand how openal works, but i'm having problems playing more then one sound at a time if i do try play another sound the sound that is currently running restarts, and new one is not played, i've had a look at some of the tutorials but just can't get it to run, i think it may need a for loop or something in the playSound() method, but not sure any help would, thx

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157

package org.newdawn.spaceinvaders;
import java.nio.IntBuffer;

import org.lwjgl.BufferUtils;
import org.lwjgl.LWJGLException;
import org.lwjgl.openal.AL;
import org.lwjgl.openal.AL10;
import org.lwjgl.test.openal.WaveData;


/**
 * $Id: SoundManager.java,v 1.1 2004/06/12 19:59:20 matzon Exp $
 * <p>
 * Simple sound manager for OpenAL using n sources accessed in
 * a round robin schedule. Source n is reserved for a single buffer and checking for
 * whether it's playing.
 * </p>
 * @author Brian Matzon <brian@matzon.dk>
 * @version $Revision: 1.1 $
 */
public class SoundManager {

  /** We support at most 256 buffers*/
  private int[] buffers = new int[256];
  
  /** Number of sources is limited tby user (and hardware) */
  private int[] sources;
  
  /** Our internal scratch buffer */
  private IntBuffer scratchBuffer = BufferUtils.createIntBuffer(256);
  
  /** Whether we're running in no sound mode */
  private boolean soundOutput;
  
  /** Current index in our buffers */
  private int bufferIndex;
  
  /** Current index in our source list */
  private int sourceIndex;
  
  /**
   * Creates a new SoundManager
   */
  public SoundManager() {
  }

  /**
   * Plays a sound effect
   * @param buffer Buffer index to play gotten from addSound 
   */
  public void playEffect(int buffer) {
    if(soundOutput) {
      // make sure we never choose last channel, since it is used for special sounds
          int channel = sources[(sourceIndex++ % (sources.length-1))];
      
      // link buffer and source, and play it
          AL10.alSourcei(channel, AL10.AL_BUFFER, buffers[buffer]);
          AL10.alSourcePlay(channel);
    }
  }

  /**
   * Plays a sound on last source
   * @param buffer Buffer index to play gotten from addSound
   */
  public void playSound(int buffer) {
    if(soundOutput) {
      AL10.alSourcei(sources[sources.length-1], AL10.AL_BUFFER, buffers[buffer]);
      AL10.alSourcePlay(sources[sources.length-1]);
    }
  }
  
  /**
   * Whether a sound is playing on last source
   * @return true if a source is playing right now on source n
   */
  public boolean isPlayingSound() {
        return AL10.alGetSourcei(sources[sources.length-1], AL10.AL_SOURCE_STATE) == AL10.AL_PLAYING;
  }
  
  /**
   * Initializes the SoundManager
   * 
   * @param sources Number of sources to create
   */
  public void initialize(int channels) {
    try {
     AL.create();
     
     // allocate sources
     scratchBuffer.limit(channels);
     AL10.alGenSources(scratchBuffer);
     scratchBuffer.rewind();
     scratchBuffer.get(sources = new int[channels]);
     
     // could we allocate all channels?
     if(AL10.alGetError() != AL10.AL_NO_ERROR) {
           throw new LWJGLException("Unable to allocate " + channels + " sources");
     }
     
     // we have sound
     soundOutput = true;
    } catch (LWJGLException le) {
          le.printStackTrace();
      System.out.println("Sound disabled");
    }
  }
  
  /**
   * Adds a sound to the Sound Managers pool
   * 
   * @param path Path to file to load
   * @return index into SoundManagers buffer list
   */
  public int addSound(String path) {
    // Generate 1 buffer entry
    scratchBuffer.rewind().position(0).limit(1);
    AL10.alGenBuffers(scratchBuffer);
    buffers[bufferIndex] = scratchBuffer.get(0);
    
    // load wave data from buffer
    WaveData wavefile = WaveData.create("sounds/" + path);

    // copy to buffers
    AL10.alBufferData(buffers[bufferIndex], wavefile.format, wavefile.data, wavefile.samplerate);
    
    // unload file again
    wavefile.dispose();        
    
    // return index for this sound
        return bufferIndex++;
  }
  
  /**
   * Destroy this SoundManager
   */
  public void destroy() {
    if(soundOutput) {
      
      // stop playing sounds
      scratchBuffer.position(0).limit(sources.length);
      scratchBuffer.put(sources).flip();
      AL10.alSourceStop(scratchBuffer);

      // destroy sources
      AL10.alDeleteSources(scratchBuffer);
      
      // destroy buffers
      scratchBuffer.position(0).limit(bufferIndex);
      scratchBuffer.put(buffers, 0, bufferIndex).flip();
      AL10.alDeleteBuffers(scratchBuffer);
      
      // destory OpenAL
          AL.destroy();
    }
  }
}