faux mastering voice + submitting static sounds

src/Audio/AudioDevice.cs

@@ -10,8 +10,12 @@ namespace MoonWorks.Audio
 		public byte[] Handle3D { get; }
 		public FAudio.FAudioDeviceDetails DeviceDetails { get; }
 
-		private MasteringVoice masteringVoice;
+		private IntPtr trueMasteringVoice;
-		public MasteringVoice MasteringVoice => masteringVoice;
+
+		// this is a fun little trick where we use a submix voice as a "faux" mastering voice
+		// this lets us maintain API consistency for effects like panning and reverb
+		private SubmixVoice fauxMasteringVoice;
+		public SubmixVoice MasteringVoice => fauxMasteringVoice;
 
 		public float CurveDistanceScalar = 1f;
 		public float DopplerScale = 1f;
@@ -19,8 +23,8 @@ 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<SoundSequence>> soundSequenceReferences = new List<WeakReference<SoundSequence>>();
+		private readonly List<SourceVoice> autoFreeSourceVoices = new List<SourceVoice>();
 
 		private AudioTweenManager AudioTweenManager;
 
@@ -85,18 +89,25 @@ namespace MoonWorks.Audio
 			}
 
 			/* Init Mastering Voice */
-			var result = MasteringVoice.Create(
+			var result = FAudio.FAudio_CreateMasteringVoice(
-				this,
+				Handle,
+				out trueMasteringVoice,
+				FAudio.FAUDIO_DEFAULT_CHANNELS,
+				FAudio.FAUDIO_DEFAULT_SAMPLERATE,
+				0,
 				i,
-				out masteringVoice
+				IntPtr.Zero
 			);
 
-			if (!result)
+			if (result != 0)
 			{
+				Logger.LogError("Failed to create a mastering voice!");
 				Logger.LogError("Audio device creation failed!");
 				return;
 			}
 
+			fauxMasteringVoice = new SubmixVoice(this, FAudio.FAUDIO_DEFAULT_CHANNELS, FAudio.FAUDIO_DEFAULT_SAMPLERATE);
+
 			/* Init 3D Audio */
 
 			Handle3D = new byte[FAudio.F3DAUDIO_HANDLE_BYTESIZE];
@@ -162,17 +173,6 @@ namespace MoonWorks.Audio
 				}
 			}
 
-			for (var i = autoFreeStaticSoundInstanceReferences.Count - 1; i >= 0; i -= 1)
-			{
-				var staticSoundInstance = autoFreeStaticSoundInstanceReferences[i];
-
-				if (staticSoundInstance.State == SoundState.Stopped)
-				{
-					staticSoundInstance.Free();
-					autoFreeStaticSoundInstanceReferences.RemoveAt(i);
-				}
-			}
-
 			for (var i = soundSequenceReferences.Count - 1; i >= 0; i -= 1)
 			{
 				if (soundSequenceReferences[i].TryGetTarget(out var soundSequence))
@@ -185,14 +185,61 @@ namespace MoonWorks.Audio
 				}
 			}
 
+			for (var i = autoFreeSourceVoices.Count - 1; i >= 0; i -= 1)
+			{
+				var voice = autoFreeSourceVoices[i];
+				if (voice.BuffersQueued == 0)
+				{
+					Return(voice);
+					autoFreeSourceVoices.RemoveAt(i);
+				}
+			}
+
 			AudioTweenManager.Update(elapsedSeconds);
 		}
 
+		/// <summary>
+		/// Triggers all pending operations with the given syncGroup value.
+		/// </summary>
 		public void TriggerSyncGroup(uint syncGroup)
 		{
 			FAudio.FAudio_CommitChanges(Handle, syncGroup);
 		}
 
+		/// <summary>
+		/// Obtains an appropriate source voice from the voice pool.
+		/// </summary>
+		/// <param name="format">The format that the voice must match.</param>
+		/// <returns>A source voice with the given format.</returns>
+		public SourceVoice Obtain(Format format)
+		{
+			lock (StateLock)
+			{
+				return VoicePool.Obtain(format);
+			}
+		}
+
+		internal void ReturnWhenIdle(SourceVoice voice)
+		{
+			lock (StateLock)
+			{
+				autoFreeSourceVoices.Add(voice);
+			}
+		}
+
+		/// <summary>
+		/// Returns the source voice to the voice pool.
+		/// </summary>
+		/// <param name="voice"></param>
+		internal void Return(SourceVoice voice)
+		{
+			lock (StateLock)
+			{
+				voice.Reset();
+				VoicePool.Return(voice);
+			}
+		}
+
 		internal void CreateTween(
 			Voice voice,
 			AudioTweenProperty property,
@@ -252,26 +299,11 @@ namespace MoonWorks.Audio
 			autoUpdateStreamingSoundReferences.Add(instance);
 		}
 
-		internal void AddAutoFreeStaticSoundInstance(StaticSoundInstance instance)
-		{
-			autoFreeStaticSoundInstanceReferences.Add(instance);
-		}
-
 		internal void AddSoundSequenceReference(SoundSequence sequence)
 		{
 			soundSequenceReferences.Add(new WeakReference<SoundSequence>(sequence));
 		}
 
-		internal SourceVoice ObtainSourceVoice(Format format)
-		{
-			return VoicePool.Obtain(format);
-		}
-
-		internal void ReturnSourceVoice(SourceVoice voice)
-		{
-			VoicePool.Return(voice);
-		}
-
 		protected virtual void Dispose(bool disposing)
 		{
 			if (!IsDisposed)
@@ -306,6 +338,7 @@ namespace MoonWorks.Audio
 					resources.Clear();
 				}
 
+				FAudio.FAudioVoice_DestroyVoice(trueMasteringVoice);
 				FAudio.FAudio_Release(Handle);
 
 				IsDisposed = true;

src/Audio/AudioTweenManager.cs

@@ -24,10 +24,7 @@ namespace MoonWorks.Audio
 					switch (audioTween.Property)
 					{
 						case AudioTweenProperty.Pan:
-							if (voice is SendableVoice pannableVoice)
+							audioTween.StartValue = voice.Pan;
-							{
-								audioTween.StartValue = pannableVoice.Pan;
-							}
 							break;
 
 						case AudioTweenProperty.Pitch:
@@ -43,10 +40,7 @@ namespace MoonWorks.Audio
 							break;
 
 						case AudioTweenProperty.Reverb:
-							if (voice is SendableVoice reverbableVoice)
+							audioTween.StartValue = voice.Reverb;
-							{
-								audioTween.StartValue = reverbableVoice.Reverb;
-							}
 							break;
 					}
 
@@ -139,10 +133,7 @@ namespace MoonWorks.Audio
 			switch (audioTween.Property)
 			{
 				case AudioTweenProperty.Pan:
-					if (audioTween.Voice is SendableVoice pannableVoice)
+					audioTween.Voice.Pan = value;
-					{
-						pannableVoice.Pan = value;
-					}
 					break;
 
 				case AudioTweenProperty.Pitch:
@@ -158,10 +149,7 @@ namespace MoonWorks.Audio
 					break;
 
 				case AudioTweenProperty.Reverb:
-					if (audioTween.Voice is SendableVoice reverbableVoice)
+					audioTween.Voice.Reverb = value;
-					{
-						reverbableVoice.Reverb = value;
-					}
 					break;
 			}
 

src/Audio/IReceivableVoice.cs

@@ -1,7 +0,0 @@
-namespace MoonWorks.Audio
-{
-	public interface IReceivableVoice
-	{
-		public System.IntPtr Handle { get; }
-	}
-}

src/Audio/MasteringVoice.cs

@@ -1,43 +0,0 @@
-using System;
-
-namespace MoonWorks.Audio
-{
-	public class MasteringVoice : Voice, IReceivableVoice
-	{
-		internal static bool Create(
-			AudioDevice device,
-			uint deviceIndex,
-			out MasteringVoice masteringVoice
-		) {
-			var result = FAudio.FAudio_CreateMasteringVoice(
-				device.Handle,
-				out var handle,
-				FAudio.FAUDIO_DEFAULT_CHANNELS,
-				FAudio.FAUDIO_DEFAULT_SAMPLERATE,
-				0,
-				deviceIndex,
-				IntPtr.Zero
-			);
-
-			if (result == 0)
-			{
-				masteringVoice = new MasteringVoice(device, handle);
-			}
-			else
-			{
-				Logger.LogError("Failed to create mastering voice!");
-				masteringVoice = null;
-			}
-
-			return result == 0;
-		}
-
-		internal MasteringVoice(
-			AudioDevice device,
-			IntPtr handle
-		) : base(device, device.DeviceDetails.OutputFormat.Format.nChannels, 0)
-		{
-			this.handle = handle;
-		}
-	}
-}

src/Audio/SendableVoice.cs

@@ -1,227 +0,0 @@
-using System;
-using System.Runtime.InteropServices;
-using EasingFunction = System.Func<float, float>;
-
-namespace MoonWorks.Audio
-{
-	public unsafe class SendableVoice : Voice
-	{
-		private IReceivableVoice OutputVoice;
-		private ReverbEffect ReverbEffect;
-
-		byte* pMatrixCoefficients;
-
-		protected float pan = 0;
-		public float Pan
-		{
-			get => pan;
-			internal set
-			{
-				value = Math.MathHelper.Clamp(value, -1f, 1f);
-				if (pan != value)
-				{
-					pan = value;
-
-					if (pan < -1f)
-					{
-						pan = -1f;
-					}
-					if (pan > 1f)
-					{
-						pan = 1f;
-					}
-
-					if (Is3D) { return; }
-
-					SetPanMatrixCoefficients();
-					FAudio.FAudioVoice_SetOutputMatrix(
-						Handle,
-						OutputVoice.Handle,
-						SourceChannelCount,
-						DestinationChannelCount,
-						(nint) pMatrixCoefficients,
-						0
-					);
-				}
-			}
-		}
-
-		private float reverb;
-		public unsafe float Reverb
-		{
-			get => reverb;
-			internal set
-			{
-				if (ReverbEffect != null)
-				{
-					value = MathF.Max(0, value);
-					if (reverb != value)
-					{
-						reverb = value;
-
-						float* outputMatrix = (float*) pMatrixCoefficients;
-						outputMatrix[0] = reverb;
-						if (SourceChannelCount == 2)
-						{
-							outputMatrix[1] = reverb;
-						}
-
-						FAudio.FAudioVoice_SetOutputMatrix(
-							Handle,
-							ReverbEffect.Handle,
-							SourceChannelCount,
-							1,
-							(nint) pMatrixCoefficients,
-							0
-						);
-					}
-				}
-
-				#if DEBUG
-				if (ReverbEffect == null)
-				{
-					Logger.LogWarn("Tried to set reverb value before applying a reverb effect");
-				}
-				#endif
-			}
-		}
-
-		public SendableVoice(AudioDevice device, uint sourceChannelCount, uint destinationChannelCount) : base(device, sourceChannelCount, destinationChannelCount)
-		{
-			OutputVoice = device.MasteringVoice;
-			nuint memsize = (nuint) (4 * sourceChannelCount * destinationChannelCount);
-			pMatrixCoefficients = (byte*) NativeMemory.AllocZeroed(memsize);
-			SetPanMatrixCoefficients();
-		}
-
-		public virtual void SetPan(float targetValue)
-		{
-			Pan = targetValue;
-			Device.ClearTweens(this, AudioTweenProperty.Pan);
-		}
-
-		public virtual void SetPan(float targetValue, float duration, EasingFunction easingFunction)
-		{
-			Device.CreateTween(this, AudioTweenProperty.Pan, easingFunction, Pan, targetValue, duration, 0);
-		}
-
-		public virtual void SetPan(float targetValue, float delayTime, float duration, EasingFunction easingFunction)
-		{
-			Device.CreateTween(this, AudioTweenProperty.Pan, easingFunction, Pan, targetValue, duration, delayTime);
-		}
-
-		public virtual void SetReverb(float targetValue)
-		{
-			Reverb = targetValue;
-			Device.ClearTweens(this, AudioTweenProperty.Reverb);
-		}
-
-		public virtual void SetReverb(float targetValue, float duration, EasingFunction easingFunction)
-		{
-			Device.CreateTween(this, AudioTweenProperty.Reverb, easingFunction, Volume, targetValue, duration, 0);
-		}
-
-		public virtual void SetReverb(float targetValue, float delayTime, float duration, EasingFunction easingFunction)
-		{
-			Device.CreateTween(this, AudioTweenProperty.Reverb, easingFunction, Volume, targetValue, duration, delayTime);
-		}
-
-		public unsafe void SetOutputVoice(IReceivableVoice send)
-		{
-			FAudio.FAudioSendDescriptor* sendDesc = stackalloc FAudio.FAudioSendDescriptor[1];
-			sendDesc[0].Flags = 0;
-			sendDesc[0].pOutputVoice = send.Handle;
-
-			var sends = new FAudio.FAudioVoiceSends();
-			sends.SendCount = 1;
-			sends.pSends = (nint) sendDesc;
-
-			FAudio.FAudioVoice_SetOutputVoices(
-				Handle,
-				ref sends
-			);
-
-			OutputVoice = send;
-		}
-
-		public virtual unsafe void SetReverbEffectChain(ReverbEffect reverbEffect)
-		{
-			var sendDesc = stackalloc FAudio.FAudioSendDescriptor[2];
-			sendDesc[0].Flags = 0;
-			sendDesc[0].pOutputVoice = OutputVoice.Handle;
-			sendDesc[1].Flags = 0;
-			sendDesc[1].pOutputVoice = reverbEffect.Handle;
-
-			var sends = new FAudio.FAudioVoiceSends();
-			sends.SendCount = 2;
-			sends.pSends = (nint) sendDesc;
-
-			FAudio.FAudioVoice_SetOutputVoices(
-				Handle,
-				ref sends
-			);
-
-			ReverbEffect = reverbEffect;
-		}
-
-		// Taken from https://github.com/FNA-XNA/FNA/blob/master/src/Audio/SoundEffectInstance.cs
-		private unsafe void SetPanMatrixCoefficients()
-		{
-			/* Two major things to notice:
-			 * 1. The spec assumes any speaker count >= 2 has Front Left/Right.
-			 * 2. Stereo panning is WAY more complicated than you think.
-			 *    The main thing is that hard panning does NOT eliminate an
-			 *    entire channel; the two channels are blended on each side.
-			 * -flibit
-			 */
-			float* outputMatrix = (float*) pMatrixCoefficients;
-			if (SourceChannelCount == 1)
-			{
-				if (DestinationChannelCount == 1)
-				{
-					outputMatrix[0] = 1.0f;
-				}
-				else
-				{
-					outputMatrix[0] = (pan > 0.0f) ? (1.0f - pan) : 1.0f;
-					outputMatrix[1] = (pan < 0.0f) ? (1.0f + pan) : 1.0f;
-				}
-			}
-			else
-			{
-				if (DestinationChannelCount == 1)
-				{
-					outputMatrix[0] = 1.0f;
-					outputMatrix[1] = 1.0f;
-				}
-				else
-				{
-					if (pan <= 0.0f)
-					{
-						// Left speaker blends left/right channels
-						outputMatrix[0] = 0.5f * pan + 1.0f;
-						outputMatrix[1] = 0.5f * -pan;
-						// Right speaker gets less of the right channel
-						outputMatrix[2] = 0.0f;
-						outputMatrix[3] = pan + 1.0f;
-					}
-					else
-					{
-						// Left speaker gets less of the left channel
-						outputMatrix[0] = -pan + 1.0f;
-						outputMatrix[1] = 0.0f;
-						// Right speaker blends right/left channels
-						outputMatrix[2] = 0.5f * pan;
-						outputMatrix[3] = 0.5f * -pan + 1.0f;
-					}
-				}
-			}
-		}
-
-		protected override unsafe void Destroy()
-		{
-			NativeMemory.Free(pMatrixCoefficients);
-			base.Destroy();
-		}
-	}
-}

src/Audio/SoundSequence.cs

@@ -59,11 +59,7 @@ namespace MoonWorks.Audio
 
 			lock (StateLock)
 			{
-				FAudio.FAudioSourceVoice_SubmitSourceBuffer(
+				Submit(sound);
-					Handle,
-					ref sound.Handle,
-					IntPtr.Zero
-				);
 			}
 		}
 	}

src/Audio/SourceVoice.cs

@@ -2,7 +2,10 @@ using System;
 
 namespace MoonWorks.Audio
 {
-	public class SourceVoice : SendableVoice
+	/// <summary>
+	/// Emits audio from submitted audio buffers.
+	/// </summary>
+	public class SourceVoice : Voice
 	{
 		private Format format;
 		public Format Format => format;
@@ -55,7 +58,7 @@ namespace MoonWorks.Audio
 
 			 FAudio.FAudio_CreateSourceVoice(
 				device.Handle,
-				out var Handle,
+				out handle,
 				ref fAudioFormat,
 				FAudio.FAUDIO_VOICE_USEFILTER,
 				FAudio.FAUDIO_DEFAULT_FREQ_RATIO,
@@ -65,6 +68,11 @@ namespace MoonWorks.Audio
 			);
 		}
 
+		/// <summary>
+		/// Starts consumption and processing of audio by the voice.
+		/// Delivers the result to any connected submix or mastering voice.
+		/// </summary>
+		/// <param name="syncGroup">Optional. Denotes that the operation will be pending until AudioDevice.TriggerSyncGroup is called.</param>
 		public void Play(uint syncGroup = FAudio.FAUDIO_COMMIT_NOW)
 		{
 			lock (StateLock)
@@ -75,6 +83,11 @@ namespace MoonWorks.Audio
 			}
 		}
 
+		/// <summary>
+		/// Pauses playback.
+		/// All source buffers that are queued on the voice and the current cursor position are preserved.
+		/// </summary>
+		/// <param name="syncGroup">Optional. Denotes that the operation will be pending until AudioDevice.TriggerSyncGroup is called.</param>
 		public void Pause(uint syncGroup = FAudio.FAUDIO_COMMIT_NOW)
 		{
 			lock (StateLock)
@@ -85,6 +98,11 @@ namespace MoonWorks.Audio
 			}
 		}
 
+		/// <summary>
+		/// Stops looping the voice when it reaches the end of the current loop region.
+		/// If the cursor for the voice is not in a loop region, ExitLoop does nothing.
+		/// </summary>
+		/// <param name="syncGroup">Optional. Denotes that the operation will be pending until AudioDevice.TriggerSyncGroup is called.</param>
 		public void ExitLoop(uint syncGroup = FAudio.FAUDIO_COMMIT_NOW)
 		{
 			lock (StateLock)
@@ -93,6 +111,10 @@ namespace MoonWorks.Audio
 			}
 		}
 
+		/// <summary>
+		/// Stops playback and removes all pending audio buffers from the voice queue.
+		/// </summary>
+		/// <param name="syncGroup">Optional. Denotes that the operation will be pending until AudioDevice.TriggerSyncGroup is called.</param>
 		public void Stop(uint syncGroup = FAudio.FAUDIO_COMMIT_NOW)
 		{
 			lock (StateLock)
@@ -104,7 +126,32 @@ namespace MoonWorks.Audio
 			}
 		}
 
-		public void SubmitBuffer(FAudio.FAudioBuffer buffer)
+		/// <summary>
+		/// Adds a static sound to the voice queue.
+		/// The voice processes and plays back the buffers in its queue in the order that they were submitted.
+		/// </summary>
+		/// <param name="sound">The sound to submit to the voice.</param>
+		/// <param name="loop">Designates that the voice will loop the submitted buffer.</param>
+		public void Submit(StaticSound sound, bool loop = false)
+		{
+			if (loop)
+			{
+				sound.Buffer.LoopCount = FAudio.FAUDIO_LOOP_INFINITE;
+			}
+			else
+			{
+				sound.Buffer.LoopCount = 0;
+			}
+
+			Submit(sound.Buffer);
+		}
+
+		/// <summary>
+		/// Adds an FAudio buffer to the voice queue.
+		/// The voice processes and plays back the buffers in its queue in the order that they were submitted.
+		/// </summary>
+		/// <param name="buffer">The buffer to submit to the voice.</param>
+		public void Submit(FAudio.FAudioBuffer buffer)
 		{
 			FAudio.FAudioSourceVoice_SubmitSourceBuffer(
 				Handle,
@@ -113,31 +160,27 @@ namespace MoonWorks.Audio
 			);
 		}
 
-		// FIXME: maybe this is bad
+		public void Submit(StreamingSound streamingSound)
-		// NOTE: SourceVoices obtained this way will be returned to the voice pool when stopped!
-		public static SourceVoice ObtainSourceVoice(AudioDevice device, Format format)
 		{
-			return device.ObtainSourceVoice(format);
+
 		}
 
-		// intended for short-lived sound effects
+		/// <summary>
-		public static SourceVoice PlayStaticSound(AudioDevice device, StaticSound sound, SubmixVoice sendVoice = null)
+		/// Designates that this source voice will return to the voice pool once all its buffers are exhausted.
+		/// </summary>
+		public void ReturnWhenIdle()
 		{
-			var voice = ObtainSourceVoice(device, sound.Format);
+			Device.ReturnWhenIdle(this);
+		}
 
-			if (sendVoice == null)
+		/// <summary>
-			{
+		/// Returns this source voice to the voice pool.
-				voice.SetOutputVoice(device.MasteringVoice);
+		/// </summary>
-			}
+		public void Return()
-			else
+		{
-			{
+			Stop();
-				voice.SetOutputVoice(sendVoice);
+			Reset();
-			}
+			Device.Return(this);
-
-			voice.SubmitBuffer(sound.Handle);
-			voice.Play();
-
-			return voice;
 		}
 
 		protected override unsafe void Destroy()

src/Audio/StaticSound.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Generic;
 using System.IO;
 using System.Runtime.InteropServices;
 
@@ -7,17 +6,11 @@ namespace MoonWorks.Audio
 {
 	public class StaticSound : AudioResource
 	{
-		internal FAudio.FAudioBuffer Handle;
+		internal FAudio.FAudioBuffer Buffer;
 
 		private Format format;
 		public Format Format => format;
 
-		public uint LoopStart { get; set; } = 0;
-		public uint LoopLength { get; set; } = 0;
-
-		private Stack<StaticSoundInstance> AvailableInstances = new Stack<StaticSoundInstance>();
-		private HashSet<StaticSoundInstance> UsedInstances = new HashSet<StaticSoundInstance>();
-
 		private bool OwnsBuffer;
 
 		public static unsafe StaticSound LoadOgg(AudioDevice device, string filePath)
@@ -253,10 +246,9 @@ namespace MoonWorks.Audio
 			uint bufferLengthInBytes,
 			bool ownsBuffer) : base(device)
 		{
-			// TODO: should we wrap the format struct to make it nicer?
 			this.format = format;
 
-			Handle = new FAudio.FAudioBuffer
+			Buffer = new FAudio.FAudioBuffer
 			{
 				Flags = FAudio.FAUDIO_END_OF_STREAM,
 				pContext = IntPtr.Zero,
@@ -269,66 +261,11 @@ namespace MoonWorks.Audio
 			OwnsBuffer = ownsBuffer;
 		}
 
-		/// <summary>
-		/// Gets a sound instance from the pool.
-		/// NOTE: If AutoFree is false, you will have to call StaticSoundInstance.Free() yourself or leak the instance!
-		/// </summary>
-		public StaticSoundInstance GetInstance(bool autoFree = true)
-		{
-			StaticSoundInstance instance;
-
-			lock (AvailableInstances)
-			{
-				if (AvailableInstances.Count == 0)
-				{
-					AvailableInstances.Push(new StaticSoundInstance(Device, this));
-				}
-
-				instance = AvailableInstances.Pop();
-			}
-
-			instance.AutoFree = autoFree;
-
-			lock (UsedInstances)
-			{
-				UsedInstances.Add(instance);
-			}
-
-			return instance;
-		}
-
-		internal void FreeInstance(StaticSoundInstance instance)
-		{
-			instance.Reset();
-
-			lock (UsedInstances)
-			{
-				UsedInstances.Remove(instance);
-			}
-
-			lock (AvailableInstances)
-			{
-				AvailableInstances.Push(instance);
-			}
-		}
-
 		protected override unsafe void Destroy()
 		{
-			foreach (var instance in UsedInstances)
-			{
-				instance.Free();
-			}
-
-			foreach (var instance in AvailableInstances)
-			{
-				instance.Dispose();
-			}
-
-			AvailableInstances.Clear();
-
 			if (OwnsBuffer)
 			{
-				NativeMemory.Free((void*) Handle.pAudioData);
+				NativeMemory.Free((void*) Buffer.pAudioData);
 			}
 		}
 	}

src/Audio/StaticSoundInstance.cs

@@ -1,141 +0,0 @@
-using System;
-
-namespace MoonWorks.Audio
-{
-	public class StaticSoundInstance : SoundInstance
-	{
-		public StaticSound Parent { get; }
-
-		public bool Loop { get; set; }
-
-		private SoundState _state = SoundState.Stopped;
-		public override SoundState State
-		{
-			get
-			{
-				FAudio.FAudioSourceVoice_GetState(
-					Voice,
-					out var state,
-					FAudio.FAUDIO_VOICE_NOSAMPLESPLAYED
-				);
-				if (state.BuffersQueued == 0)
-				{
-					StopImmediate();
-				}
-
-				return _state;
-			}
-
-			protected set
-			{
-				_state = value;
-			}
-		}
-
-		public bool AutoFree { get; internal set; }
-
-		internal StaticSoundInstance(
-			AudioDevice device,
-			StaticSound parent
-		) : base(device, parent.FormatTag, parent.BitsPerSample, parent.BlockAlign, parent.Channels, parent.SamplesPerSecond)
-		{
-			Parent = parent;
-		}
-
-		public override void Play()
-		{
-			PlayUsingOperationSet(0);
-		}
-
-		public override void QueueSyncPlay()
-		{
-			PlayUsingOperationSet(1);
-		}
-
-		private void PlayUsingOperationSet(uint operationSet)
-		{
-			if (State == SoundState.Playing)
-			{
-				return;
-			}
-
-			if (Loop)
-			{
-				Parent.Handle.LoopCount = 255;
-				Parent.Handle.LoopBegin = Parent.LoopStart;
-				Parent.Handle.LoopLength = Parent.LoopLength;
-			}
-			else
-			{
-				Parent.Handle.LoopCount = 0;
-				Parent.Handle.LoopBegin = 0;
-				Parent.Handle.LoopLength = 0;
-			}
-
-			FAudio.FAudioSourceVoice_SubmitSourceBuffer(
-				Voice,
-				ref Parent.Handle,
-				IntPtr.Zero
-			);
-
-			FAudio.FAudioSourceVoice_Start(Voice, 0, operationSet);
-			State = SoundState.Playing;
-
-			if (AutoFree)
-			{
-				Device.AddAutoFreeStaticSoundInstance(this);
-			}
-		}
-
-		public override void Pause()
-		{
-			if (State == SoundState.Playing)
-			{
-				FAudio.FAudioSourceVoice_Stop(Voice, 0, 0);
-				State = SoundState.Paused;
-			}
-		}
-
-		public override void Stop()
-		{
-			FAudio.FAudioSourceVoice_ExitLoop(Voice, 0);
-			State = SoundState.Stopped;
-		}
-
-		public override void StopImmediate()
-		{
-			FAudio.FAudioSourceVoice_Stop(Voice, 0, 0);
-			FAudio.FAudioSourceVoice_FlushSourceBuffers(Voice);
-			State = SoundState.Stopped;
-		}
-
-		public void Seek(uint sampleFrame)
-		{
-			if (State == SoundState.Playing)
-			{
-				FAudio.FAudioSourceVoice_Stop(Voice, 0, 0);
-				FAudio.FAudioSourceVoice_FlushSourceBuffers(Voice);
-			}
-
-			Parent.Handle.PlayBegin = sampleFrame;
-		}
-
-		// Call this when you no longer need the sound instance.
-		// If AutoFree is set, this will automatically be called when the sound instance stops playing.
-		// If the sound isn't stopped when you call this, things might get weird!
-		public void Free()
-		{
-			Parent.FreeInstance(this);
-		}
-
-		internal void Reset()
-		{
-			Pan = 0;
-			Pitch = 0;
-			Volume = 1;
-			Loop = false;
-			Is3D = false;
-			FilterType = FilterType.None;
-		}
-	}
-}

src/Audio/SubmixVoice.cs

@@ -2,7 +2,7 @@ using System;
 
 namespace MoonWorks.Audio
 {
-	public class SubmixVoice : SendableVoice, IReceivableVoice
+	public class SubmixVoice : Voice
 	{
 		public SubmixVoice(
 			AudioDevice device,

src/Audio/Voice.cs

@@ -1,9 +1,10 @@
 using System;
+using System.Runtime.InteropServices;
 using EasingFunction = System.Func<float, float>;
 
 namespace MoonWorks.Audio
 {
-	public abstract class Voice : AudioResource
+	public abstract unsafe class Voice : AudioResource
 	{
 		protected IntPtr handle;
 		public IntPtr Handle => handle;
@@ -11,6 +12,11 @@ namespace MoonWorks.Audio
 		public uint SourceChannelCount { get; }
 		public uint DestinationChannelCount { get; }
 
+		private SubmixVoice OutputVoice;
+		private ReverbEffect ReverbEffect;
+
+		byte* pMatrixCoefficients;
+
 		public bool Is3D { get; protected set; }
 
 		private float dopplerFactor;
@@ -27,21 +33,6 @@ namespace MoonWorks.Audio
 			}
 		}
 
-		private float pitch = 0;
-		public float Pitch
-		{
-			get => pitch;
-			internal set
-			{
-				value = Math.MathHelper.Clamp(value, -1f, 1f);
-				if (pitch != value)
-				{
-					pitch = value;
-					UpdatePitch();
-				}
-			}
-		}
-
 		private float volume = 1;
 		public float Volume
 		{
@@ -57,6 +48,21 @@ namespace MoonWorks.Audio
 			}
 		}
 
+		private float pitch = 0;
+		public float Pitch
+		{
+			get => pitch;
+			internal set
+			{
+				value = Math.MathHelper.Clamp(value, -1f, 1f);
+				if (pitch != value)
+				{
+					pitch = value;
+					UpdatePitch();
+				}
+			}
+		}
+
 		private const float MAX_FILTER_FREQUENCY = 1f;
 		private const float MAX_FILTER_ONEOVERQ = 1.5f;
 
@@ -150,10 +156,89 @@ namespace MoonWorks.Audio
 			}
 		}
 
+		protected float pan = 0;
+		public float Pan
+		{
+			get => pan;
+			internal set
+			{
+				value = Math.MathHelper.Clamp(value, -1f, 1f);
+				if (pan != value)
+				{
+					pan = value;
+
+					if (pan < -1f)
+					{
+						pan = -1f;
+					}
+					if (pan > 1f)
+					{
+						pan = 1f;
+					}
+
+					if (Is3D) { return; }
+
+					SetPanMatrixCoefficients();
+					FAudio.FAudioVoice_SetOutputMatrix(
+						Handle,
+						OutputVoice.Handle,
+						SourceChannelCount,
+						DestinationChannelCount,
+						(nint) pMatrixCoefficients,
+						0
+					);
+				}
+			}
+		}
+
+		private float reverb;
+		public unsafe float Reverb
+		{
+			get => reverb;
+			internal set
+			{
+				if (ReverbEffect != null)
+				{
+					value = MathF.Max(0, value);
+					if (reverb != value)
+					{
+						reverb = value;
+
+						float* outputMatrix = (float*) pMatrixCoefficients;
+						outputMatrix[0] = reverb;
+						if (SourceChannelCount == 2)
+						{
+							outputMatrix[1] = reverb;
+						}
+
+						FAudio.FAudioVoice_SetOutputMatrix(
+							Handle,
+							ReverbEffect.Handle,
+							SourceChannelCount,
+							1,
+							(nint) pMatrixCoefficients,
+							0
+						);
+					}
+				}
+
+				#if DEBUG
+				if (ReverbEffect == null)
+				{
+					Logger.LogWarn("Tried to set reverb value before applying a reverb effect");
+				}
+				#endif
+			}
+		}
+
 		public Voice(AudioDevice device, uint sourceChannelCount, uint destinationChannelCount) : base(device)
 		{
 			SourceChannelCount = sourceChannelCount;
 			DestinationChannelCount = destinationChannelCount;
+			OutputVoice = device.MasteringVoice;
+			nuint memsize = 4 * sourceChannelCount * destinationChannelCount;
+			pMatrixCoefficients = (byte*) NativeMemory.AllocZeroed(memsize);
+			SetPanMatrixCoefficients();
 		}
 
 		public void SetPitch(float targetValue)
@@ -209,6 +294,159 @@ namespace MoonWorks.Audio
 			FilterOneOverQ = targetValue;
 		}
 
+		public virtual void SetPan(float targetValue)
+		{
+			Pan = targetValue;
+			Device.ClearTweens(this, AudioTweenProperty.Pan);
+		}
+
+		public virtual void SetPan(float targetValue, float duration, EasingFunction easingFunction)
+		{
+			Device.CreateTween(this, AudioTweenProperty.Pan, easingFunction, Pan, targetValue, duration, 0);
+		}
+
+		public virtual void SetPan(float targetValue, float delayTime, float duration, EasingFunction easingFunction)
+		{
+			Device.CreateTween(this, AudioTweenProperty.Pan, easingFunction, Pan, targetValue, duration, delayTime);
+		}
+
+		public virtual void SetReverb(float targetValue)
+		{
+			Reverb = targetValue;
+			Device.ClearTweens(this, AudioTweenProperty.Reverb);
+		}
+
+		public virtual void SetReverb(float targetValue, float duration, EasingFunction easingFunction)
+		{
+			Device.CreateTween(this, AudioTweenProperty.Reverb, easingFunction, Volume, targetValue, duration, 0);
+		}
+
+		public virtual void SetReverb(float targetValue, float delayTime, float duration, EasingFunction easingFunction)
+		{
+			Device.CreateTween(this, AudioTweenProperty.Reverb, easingFunction, Volume, targetValue, duration, delayTime);
+		}
+
+		public unsafe void SetOutputVoice(SubmixVoice send)
+		{
+			OutputVoice = send;
+
+			if (ReverbEffect != null)
+			{
+				SetReverbEffectChain(ReverbEffect);
+			}
+			else
+			{
+				FAudio.FAudioSendDescriptor* sendDesc = stackalloc FAudio.FAudioSendDescriptor[1];
+				sendDesc[0].Flags = 0;
+				sendDesc[0].pOutputVoice = send.Handle;
+
+				var sends = new FAudio.FAudioVoiceSends();
+				sends.SendCount = 1;
+				sends.pSends = (nint) sendDesc;
+
+				FAudio.FAudioVoice_SetOutputVoices(
+					Handle,
+					ref sends
+				);
+			}
+		}
+
+		public unsafe void SetReverbEffectChain(ReverbEffect reverbEffect)
+		{
+			var sendDesc = stackalloc FAudio.FAudioSendDescriptor[2];
+			sendDesc[0].Flags = 0;
+			sendDesc[0].pOutputVoice = OutputVoice.Handle;
+			sendDesc[1].Flags = 0;
+			sendDesc[1].pOutputVoice = reverbEffect.Handle;
+
+			var sends = new FAudio.FAudioVoiceSends();
+			sends.SendCount = 2;
+			sends.pSends = (nint) sendDesc;
+
+			FAudio.FAudioVoice_SetOutputVoices(
+				Handle,
+				ref sends
+			);
+
+			ReverbEffect = reverbEffect;
+		}
+
+		public void RemoveReverbEffectChain()
+		{
+			if (ReverbEffect != null)
+			{
+				ReverbEffect = null;
+				reverb = 0;
+				SetOutputVoice(OutputVoice);
+			}
+		}
+
+		// Taken from https://github.com/FNA-XNA/FNA/blob/master/src/Audio/SoundEffectInstance.cs
+		private unsafe void SetPanMatrixCoefficients()
+		{
+			/* Two major things to notice:
+			 * 1. The spec assumes any speaker count >= 2 has Front Left/Right.
+			 * 2. Stereo panning is WAY more complicated than you think.
+			 *    The main thing is that hard panning does NOT eliminate an
+			 *    entire channel; the two channels are blended on each side.
+			 * -flibit
+			 */
+			float* outputMatrix = (float*) pMatrixCoefficients;
+			if (SourceChannelCount == 1)
+			{
+				if (DestinationChannelCount == 1)
+				{
+					outputMatrix[0] = 1.0f;
+				}
+				else
+				{
+					outputMatrix[0] = (pan > 0.0f) ? (1.0f - pan) : 1.0f;
+					outputMatrix[1] = (pan < 0.0f) ? (1.0f + pan) : 1.0f;
+				}
+			}
+			else
+			{
+				if (DestinationChannelCount == 1)
+				{
+					outputMatrix[0] = 1.0f;
+					outputMatrix[1] = 1.0f;
+				}
+				else
+				{
+					if (pan <= 0.0f)
+					{
+						// Left speaker blends left/right channels
+						outputMatrix[0] = 0.5f * pan + 1.0f;
+						outputMatrix[1] = 0.5f * -pan;
+						// Right speaker gets less of the right channel
+						outputMatrix[2] = 0.0f;
+						outputMatrix[3] = pan + 1.0f;
+					}
+					else
+					{
+						// Left speaker gets less of the left channel
+						outputMatrix[0] = -pan + 1.0f;
+						outputMatrix[1] = 0.0f;
+						// Right speaker blends right/left channels
+						outputMatrix[2] = 0.5f * pan;
+						outputMatrix[3] = 0.5f * -pan + 1.0f;
+					}
+				}
+			}
+		}
+
+		public virtual void Reset()
+		{
+			RemoveReverbEffectChain();
+			Volume = 1;
+			Pan = 0;
+			Pitch = 0;
+			FilterType = FilterType.None;
+			FilterFrequency = 1;
+			FilterOneOverQ = 1;
+			SetOutputVoice(Device.MasteringVoice);
+		}
+
 		private void UpdatePitch()
 		{
 			float doppler;
@@ -231,6 +469,7 @@ namespace MoonWorks.Audio
 
 		protected unsafe override void Destroy()
 		{
+			NativeMemory.Free(pMatrixCoefficients);
 			FAudio.FAudioVoice_DestroyVoice(Handle);
 		}
 	}