MoonWorks/src/Audio/SourceVoice.cs

using System;

namespace MoonWorks.Audio
{
	public class SourceVoice : Voice
	{
		protected FAudio.FAudioWaveFormatEx Format;

		protected object StateLock = new object();

		public uint BuffersQueued
		{
			get
			{
				FAudio.FAudioSourceVoice_GetState(
					Handle,
					out var state,
					FAudio.FAUDIO_VOICE_NOSAMPLESPLAYED
				);

				return state.BuffersQueued;
			}
		}

		private SoundState state;
		public SoundState State
		{
			get
			{
				if (BuffersQueued == 0)
				{
					Stop();
				}

				return state;
			}

			internal set
			{
				state = value;
			}
		}

		public delegate void OnUpdateFunc();
		public OnUpdateFunc OnUpdate; // called by AudioDevice thread

		public SourceVoice(
			AudioDevice device,
			ushort formatTag,
			ushort bitsPerSample,
			ushort blockAlign,
			ushort channels,
			uint samplesPerSecond
		) : base(device)
		{
			Format = new FAudio.FAudioWaveFormatEx
			{
				wFormatTag = formatTag,
				wBitsPerSample = bitsPerSample,
				nChannels = channels,
				nBlockAlign = blockAlign,
				nSamplesPerSec = samplesPerSecond,
				nAvgBytesPerSec = blockAlign * samplesPerSecond
			};

			 FAudio.FAudio_CreateSourceVoice(
				device.Handle,
				out var Handle,
				ref Format,
				FAudio.FAUDIO_VOICE_USEFILTER,
				FAudio.FAUDIO_DEFAULT_FREQ_RATIO,
				IntPtr.Zero,
				IntPtr.Zero, // default sends to mastering voice!
				IntPtr.Zero
			);
		}

		public void Play(uint syncGroup = FAudio.FAUDIO_COMMIT_NOW)
		{
			lock (StateLock)
			{
				FAudio.FAudioSourceVoice_Start(Handle, 0, syncGroup);

				State = SoundState.Playing;
			}
		}

		public void Pause(uint syncGroup = FAudio.FAUDIO_COMMIT_NOW)
		{
			lock (StateLock)
			{
				FAudio.FAudioSourceVoice_Stop(Handle, 0, syncGroup);

				State = SoundState.Paused;
			}
		}

		public void ExitLoop(uint syncGroup = FAudio.FAUDIO_COMMIT_NOW)
		{
			lock (StateLock)
			{
				FAudio.FAudioSourceVoice_ExitLoop(Handle, syncGroup);
			}
		}

		public void Stop(uint syncGroup = FAudio.FAUDIO_COMMIT_NOW)
		{
			lock (StateLock)
			{
				FAudio.FAudioSourceVoice_Stop(Handle, 0, syncGroup);
				FAudio.FAudioSourceVoice_FlushSourceBuffers(Handle);

				State = SoundState.Stopped;
			}
		}

		protected override unsafe void Destroy()
		{
			Stop();
			base.Destroy();
		}
	}
}