From 83eb268a4aa2c646665bd5b03510befc7dfa6098 Mon Sep 17 00:00:00 2001
From: cosmonaut <evan@moonside.games>
Date: Wed, 20 Apr 2022 14:29:46 -0700
Subject: [PATCH] add audio Seek functionality

---
 src/Audio/SoundInstance.cs       |  2 ++
 src/Audio/StaticSoundInstance.cs | 25 +++++++++++++++++++++++++
 src/Audio/StreamingSoundOgg.cs   | 29 +++++++++++++++++++++++++++++
 3 files changed, 56 insertions(+)

diff --git a/src/Audio/SoundInstance.cs b/src/Audio/SoundInstance.cs
index 731237e..7a77fdf 100644
--- a/src/Audio/SoundInstance.cs
+++ b/src/Audio/SoundInstance.cs
@@ -241,6 +241,8 @@ namespace MoonWorks.Audio
 		public abstract void Play(bool loop);
 		public abstract void Pause();
 		public abstract void Stop(bool immediate);
+		public abstract void Seek(float seconds);
+		public abstract void Seek(uint sampleFrame);
 
 		private void InitDSPSettings(uint srcChannels)
 		{
diff --git a/src/Audio/StaticSoundInstance.cs b/src/Audio/StaticSoundInstance.cs
index cb7966a..1afbb0d 100644
--- a/src/Audio/StaticSoundInstance.cs
+++ b/src/Audio/StaticSoundInstance.cs
@@ -93,6 +93,31 @@ namespace MoonWorks.Audio
 			}
 		}
 
+		private void PerformSeek(uint sampleFrame)
+		{
+			if (State == SoundState.Playing)
+			{
+				FAudio.FAudioSourceVoice_Stop(Handle, 0, 0);
+				FAudio.FAudioSourceVoice_FlushSourceBuffers(Handle);
+			}
+
+			Parent.Handle.PlayBegin = sampleFrame;
+			Play();
+		}
+
+		public override void Seek(float seconds)
+		{
+			uint sampleFrame =
+				(uint) (Parent.SamplesPerSecond * seconds);
+
+			PerformSeek(sampleFrame);
+		}
+
+		public override void Seek(uint sampleFrame)
+		{
+			PerformSeek(sampleFrame);
+		}
+
 		public void Free()
 		{
 			Parent.FreeInstance(this);
diff --git a/src/Audio/StreamingSoundOgg.cs b/src/Audio/StreamingSoundOgg.cs
index a83e95a..8aa4721 100644
--- a/src/Audio/StreamingSoundOgg.cs
+++ b/src/Audio/StreamingSoundOgg.cs
@@ -62,6 +62,35 @@ namespace MoonWorks.Audio
 			device.AddDynamicSoundInstance(this);
 		}
 
+		private void PerformSeek(uint sampleFrame)
+		{
+			if (State == SoundState.Playing)
+			{
+				FAudio.FAudioSourceVoice_Stop(Handle, 0, 0);
+			}
+
+			FAudio.FAudioSourceVoice_FlushSourceBuffers(Handle);
+			ClearBuffers();
+			FAudio.stb_vorbis_seek(VorbisHandle, sampleFrame);
+			QueueBuffers();
+
+			if (State == SoundState.Playing)
+			{
+				Play();
+			}
+		}
+
+		public override void Seek(float seconds)
+		{
+			uint sampleFrame = (uint) (Info.sample_rate * seconds);
+			PerformSeek(sampleFrame);
+		}
+
+		public override void Seek(uint sampleFrame)
+		{
+			PerformSeek(sampleFrame);
+		}
+
 		protected override void AddBuffer(
 			out float[] buffer,
 			out uint bufferOffset,