add SoundQueue

src/Audio/AudioDevice.cs

@@ -30,6 +30,7 @@ namespace MoonWorks.Audio
 		private readonly HashSet<WeakReference> resources = new HashSet<WeakReference>();
 		private readonly List<StreamingSound> autoUpdateStreamingSoundReferences = new List<StreamingSound>();
 		private readonly List<StaticSoundInstance> autoFreeStaticSoundInstanceReferences = new List<StaticSoundInstance>();
+		private readonly List<WeakReference<SoundQueue>> soundQueueReferences = new List<WeakReference<SoundQueue>>();
 
 		private AudioTweenManager AudioTweenManager;
 
@@ -184,6 +185,18 @@ namespace MoonWorks.Audio
 				}
 			}
 
+			for (var i = soundQueueReferences.Count - 1; i >= 0; i -= 1)
+			{
+				if (soundQueueReferences[i].TryGetTarget(out var soundQueue))
+				{
+					soundQueue.Update();
+				}
+				else
+				{
+					soundQueueReferences.RemoveAt(i);
+				}
+			}
+
 			AudioTweenManager.Update(elapsedSeconds);
 		}
 
@@ -256,6 +269,11 @@ namespace MoonWorks.Audio
 			autoFreeStaticSoundInstanceReferences.Add(instance);
 		}
 
+		internal void AddSoundQueueReference(SoundQueue queue)
+		{
+			soundQueueReferences.Add(new WeakReference<SoundQueue>(queue));
+		}
+
 		protected virtual void Dispose(bool disposing)
 		{
 			if (!IsDisposed)

src/Audio/SoundQueue.cs

@@ -0,0 +1,132 @@
+using System;
+
+namespace MoonWorks.Audio
+{
+	// NOTE: all sounds played with a playlist must have the same audio format!
+	public class SoundQueue : SoundInstance
+	{
+		public int NeedBufferThreshold = 0;
+		private uint queuedBufferCount = 0;
+
+		public delegate void OnBufferNeededFunc();
+		public OnBufferNeededFunc OnBufferNeeded;
+
+		private object StateLock = new object();
+
+		public SoundQueue(AudioDevice device, ushort formatTag, ushort bitsPerSample, ushort blockAlign, ushort channels, uint samplesPerSecond) : base(device, formatTag, bitsPerSample, blockAlign, channels, samplesPerSecond)
+		{
+			device.AddSoundQueueReference(this);
+		}
+
+		public SoundQueue(AudioDevice device, StaticSound templateSound) : base(device, templateSound.FormatTag, templateSound.BitsPerSample, templateSound.BlockAlign, templateSound.Channels, templateSound.SamplesPerSecond)
+		{
+			device.AddSoundQueueReference(this);
+		}
+
+		public void Update()
+		{
+			lock (StateLock)
+			{
+				if (IsDisposed) { return; }
+				if (State != SoundState.Playing) { return; }
+
+				if (NeedBufferThreshold > 0)
+				{
+					FAudio.FAudioSourceVoice_GetState(
+						Voice,
+						out var state,
+						FAudio.FAUDIO_VOICE_NOSAMPLESPLAYED
+					);
+
+					var queuedBufferCount = state.BuffersQueued;
+					for (int i = 0; i < NeedBufferThreshold - queuedBufferCount; i += 1)
+					{
+						if (OnBufferNeeded != null)
+						{
+							OnBufferNeeded();
+						}
+					}
+				}
+			}
+		}
+
+		public void EnqueueSound(StaticSound sound)
+		{
+#if DEBUG
+			if (
+				sound.FormatTag != Format.wFormatTag ||
+				sound.BitsPerSample != Format.wBitsPerSample ||
+				sound.Channels != Format.nChannels ||
+				sound.SamplesPerSecond != Format.nSamplesPerSec
+			)
+			{
+				Logger.LogWarn("Playlist audio format mismatch!");
+			}
+#endif
+
+			lock (StateLock)
+			{
+				FAudio.FAudioSourceVoice_SubmitSourceBuffer(
+					Voice,
+					ref sound.Handle,
+					IntPtr.Zero
+				);
+			}
+		}
+
+		public override void Pause()
+		{
+			lock (StateLock)
+			{
+				if (State == SoundState.Playing)
+				{
+					FAudio.FAudioSourceVoice_Stop(Voice, 0, 0);
+					State = SoundState.Paused;
+				}
+			}
+		}
+
+		public override void Play()
+		{
+			PlayUsingOperationSet(0);
+		}
+
+		public override void QueueSyncPlay()
+		{
+			PlayUsingOperationSet(1);
+		}
+
+		private void PlayUsingOperationSet(uint operationSet)
+		{
+			lock (StateLock)
+			{
+				if (State == SoundState.Playing)
+				{
+					return;
+				}
+
+				FAudio.FAudioSourceVoice_Start(Voice, 0, operationSet);
+				State = SoundState.Playing;
+			}
+		}
+
+		public override void Stop()
+		{
+			lock (StateLock)
+			{
+				FAudio.FAudioSourceVoice_ExitLoop(Voice, 0);
+				State = SoundState.Stopped;
+			}
+		}
+
+		public override void StopImmediate()
+		{
+			lock (StateLock)
+			{
+				FAudio.FAudioSourceVoice_Stop(Voice, 0, 0);
+				FAudio.FAudioSourceVoice_FlushSourceBuffers(Voice);
+				State = SoundState.Stopped;
+			}
+		}
+	}
+}