/Multimedia/OpenTK/OggMusicData.cs

using System;

using System.IO;

using Delta.Multimedia.BaseOpenAL;

using Delta.Utilities;

using Delta.Utilities.Helpers;

using OpenTK.Audio.OpenAL;



namespace Delta.Multimedia.OpenTK

{

	/// <summary>

	/// OGG music data

	/// </summary>

	internal class OggMusicData

	{

		#region Constants

		/// <summary>

		/// Size of a stream buffer in bytes.

		/// </summary>

		private const int BufferSize = 4096 * 8;

		#endregion



		#region Format (Public)

		/// <summary>

		/// Format

		/// </summary>

		public ALFormat Format

		{

			get;

			private set;

		}

		#endregion



		#region SampleRate (Public)

		/// <summary>

		/// Sample rate

		/// </summary>

		public int SampleRate

		{

			get;

			private set;

		}

		#endregion



		#region BufferHandles (Public)

		/// <summary>

		/// OpenAL buffers for music streaming.

		/// </summary>

		public int[] BufferHandles

		{

			get;

			private set;

		}

		#endregion



		#region Handle (Public)

		/// <summary>

		/// OpenAL source handle.

		/// </summary>

		public int Handle

		{

			get;

			private set;

		}

		#endregion



		#region Private



		#region oggFileStream (Private)

		/// <summary>

		/// The direct stream to the OGG file that we store for later disposing.

		/// </summary>

		private Stream oggFileStream;

		#endregion



		#region oggStream (Private)

		/// <summary>

		/// Decoding OGG input stream for loading the music data.

		/// </summary>

		private OggInputStream oggStream;

		#endregion



		#region contentPath (Private)

		/// <summary>

		/// The path to the music content file.

		/// </summary>

		private readonly string contentPath;

		#endregion



		#endregion



		#region Constructors

		/// <summary>

		/// Create OGG music data

		/// </summary>

		/// <param name="relativeFilePath">

		/// The path to the music content file.

		/// </param>

		public OggMusicData(string relativeFilePath)

		{

			contentPath = relativeFilePath;

			oggFileStream = FileHelper.OpenFileAsStream(contentPath);

			oggStream = new OggInputStream(oggFileStream);



			Format = oggStream.Format;

			SampleRate = oggStream.SampleRate;



			if (SampleRate == 0)

			{

				Log.Warning(

					"Loading Ogg music file '" + contentPath +

					"' failed, nothing found to play back, the file is probably not " +

					"in the ogg format! Try to upload it again and test with the " +

					"ContentManager to make sure the music file works correctly.");

			}



			BufferHandles = OpenALBinding.GenBuffers(2);

			Handle = OpenALBinding.GenSource();

			OpenALBinding.CheckError();



			if (Handle == MathHelper.InvalidIndex)

			{

				Log.Warning(

					"OggMusicData failed to load the music file '" + contentPath + "'");

			}

		}

		#endregion



		#region Rewind (Public)

		/// <summary>

		/// Rewind the music stream to the start position, used for looping and

		/// called when the music finished playing.

		/// </summary>

		public void Rewind()

		{

			oggFileStream.Close();

			oggFileStream = FileHelper.OpenFileAsStream(contentPath);

			oggStream = new OggInputStream(oggFileStream);

		}

		#endregion



		#region Stream (Public)

		/// <summary>

		/// Stream

		/// </summary>

		/// <param name="bufferHandle">The buffer handle.</param>

		/// <returns>

		/// amount of buffered bytes

		/// </returns>

		public bool Stream(int bufferHandle)

		{

			byte[] data = new byte[BufferSize];

			int size = 0;

			int result;



			while (size < BufferSize)

			{

				result = oggStream.Read(data, size, BufferSize - size);

				if (result > 0)

				{

					size += result;

				}

				else if (result < 0)

				{

					throw new Exception("Stream Error: " + result);

				}

				else

				{

					break;

				}

			}



			bool dataAvailable = (size > 0);

			if (dataAvailable)

			{

				OpenALBinding.BufferData(bufferHandle, Format, data, SampleRate);

			}



			return dataAvailable;

		}

		#endregion



		#region Dispose (Public)

		/// <summary>

		/// Dispose the source and all buffers of the ogg music.

		/// </summary>

		public void Dispose()

		{

			// Nothing to do if this was already disposed

			if (Handle == MathHelper.InvalidIndex)

			{

				return;

			}



			if (oggFileStream != null)

			{

				oggFileStream.Close();

			}

			oggStream = null;



			// Otherwise do the normal disposing. First stop the source playback

			OpenALBinding.StopSource(Handle);

			OpenALBinding.CheckError();



			// and empty the buffer queue.

			int queued = OpenALBinding.GetBuffersQueued(Handle);

			while (queued-- != 0)

			{

				OpenALBinding.SourceUnqueueBuffers(Handle, 1);

			}



			// Delete the music source

			OpenALBinding.DeleteSource(Handle);

			Handle = MathHelper.InvalidIndex;



			// And finally delete the buffers

			OpenALBinding.DeleteBuffers(BufferHandles);

			OpenALBinding.CheckError();

		}

		#endregion

	}

}