OpenALでの使用例

OpenAL.cs

//略

IntPtr device;
OpenTK.ContextHandle context;

private void button1_Click(object sender, EventArgs e)
{
        if (_tokenSource == null) _tokenSource = new CancellationTokenSource();
        var token = _tokenSource.Token;
        
        //初期化
        device = Alc.OpenDevice(null);
        context = Alc.CreateContext(device, (int[])null);
        Alc.MakeContextCurrent(context);
        
        string filename = Path.Combine("wav", "walk-fallen-leaves_mono.wav");
        
        //リッスンポジションなどの設定
        float[] ListenOri = { 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f }; // look.x.y.z / up.x.y.z

        
        AL.Listener(ALListener3f.Position, 0.0f, 1.5f, 0.0f);
        AL.Listener(ALListener3f.Velocity, 0.0f, 0.0f, 0.0f);
        AL.Listener(ALListenerfv.Orientation, ref ListenOri);
        AL.Listener(ALListenerf.Gain, 1.0f);
        
        //buffer とsourceのひもづけ
        var buffer = createBuffer(filename);
        var source = AL.GenSource();
        AL.BindBufferToSource(source, buffer);
        
        //ソースの設定
        AL.Source(source[0], ALSourceb.Looping, true);  // 繰り返し
        AL.Source(source[0], ALSourcef.Pitch, 1.0f); //
        AL.Source(source[0], ALSourcef.Gain, 1.0f);     // 音量
        AL.Source(source[0], ALSource3f.Position, 0.0f, 0.0f, 0.0f);
        
        AL.SourcePlay(source);
        
        
        //1周16秒で円を描きたい 2πr
        //2*3*3 18m
        //を16秒は妥当かな？
        int i = 0;
        int n = 160;
        double rate = 0.0d;
        double r = 2.0d;
        float x;
        float z;
        
        Task.Factory.StartNew(() =>
        {
                while (true)
                {
                        //円
                        //座標を計算
                        rate = (double)i / (double)n;
                        x = (float)(r * Math.Cos(2.0 * Math.PI * rate));
                        z = (float)(r * Math.Sin(2.0 * Math.PI * rate));
                        AL.Source(source, ALSource3f.Position, x, 0.0f, z);

                        System.Threading.Thread.Sleep(100);
                        i++;
                        //Console.WriteLine("x:{0},z:{1},i:{2},rate:{3:000.0000}", x, z, i, rate);
                        if (i == n)
                        {
                                i = 0;
                        }

                        if (token.IsCancellationRequested)
                        {
                                // TODO:キャンセル処理
                                break;
                        }

                }
        }, token).ContinueWith(t =>
        {
                // TODO:あとしまつ
                _tokenSource.Dispose();
                _tokenSource = null;

                // TODO:キャンセルされたときの処理
                AL.SourcePause(source);

                //使わなくなったデータをクリーンアップ
                AL.DeleteSource(source);
                AL.DeleteBuffer(buffer);


                Alc.MakeContextCurrent(OpenTK.ContextHandle.Zero);
                Alc.DestroyContext(context);
                Alc.CloseDevice(device);
        });
}

private static int createBuffer(string filename)
{
        int channels, bits_per_sample, sample_rate;
        var buffer = AL.GenBuffer();

        var bufferData = new byte[bufferFrequency * bufferSeconds];

        var sound_data = LoadWave(File.Open(filename, FileMode.Open), out channels, out bits_per_sample, out sample_rate);
        AL.BufferData(buffer, GetSoundFormat(channels, bits_per_sample), sound_data, sound_data.Length, sample_rate);
        return buffer;
}