Added OpenTK.Audio.AudioContext.

Source/OpenTK/OpenAL/AudioContext.cs

@@ -0,0 +1,190 @@
+#region --- License ---
+/* Copyright (c) 2008 the OpenTK team
+ * See license.txt for license details
+ * http://www.opentk.com
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+using OpenTK.OpenAL;
+using OpenTK.OpenAL.Enums;
+
+namespace OpenTK.Audio
+{
+    /// <summary>
+    /// Provides methods to create and use an audio context.
+    /// </summary>
+    public sealed class AudioContext : IDisposable
+    {
+        #region --- Fields ---
+
+        bool disposed;
+        static List<string> available_devices;
+        IntPtr device_handle, context_handle;
+        static object audio_context_lock = new object();
+
+        #endregion
+
+        #region --- Constructors ---
+
+        // Runs before the actual class constructor, to load available devices.
+        static AudioContext()
+        {
+            LoadAvailableDevices();
+        }
+
+        /// <summary>Constructs a new AudioContext, using the default audio device.</summary>
+        /// <exception cref="NotSupportedException">Occurs when no audio devices are available.</exception>
+        public AudioContext()
+        {
+            if (available_devices.Count == 0)
+                throw new NotSupportedException("No audio hardware is available.");
+            CreateContext(available_devices[0], 44100, 0, false);
+        }
+
+        /// <summary>Constructs a new AudioContext, using the specified audio device.</summary>
+        /// <param name="device">The name of the audio device to use.</param>
+        /// <remarks>
+        /// Use AudioContext.AvailableDevices to obtain a list of all available audio
+        /// devices.
+        /// </remarks>
+        public AudioContext(string device)
+        {
+            
+        }
+
+        #endregion
+
+        #region --- Private Members ---
+
+        #region static void LoadAvailableDevices()
+
+        // Loads all available audio devices into the available_devices array.
+        static void LoadAvailableDevices()
+        {
+            lock (audio_context_lock)
+            {
+                if (available_devices == null)
+                {
+                    available_devices = new List<string>();
+                    available_devices.AddRange(Alc.GetString(IntPtr.Zero, OpenTK.OpenAL.Enums.AlcGetStringList.AllDevicesSpecifier));
+                }
+            }
+        }
+
+        #endregion
+
+        #region void CreateContext(string device)
+
+        /// <private />
+        /// <summary>Creates the audio context using the specified device.</summary>
+        /// <param name="device">The device descriptor obtained through AudioContext.AvailableDevices.</param>
+        /// <param name="freq">Frequency for mixing output buffer, in units of Hz. </param>
+        /// <param name="refresh">Refresh intervalls, in units of Hz.</param>
+        /// <param name="sync">Flag, indicating a synchronous context.</param>
+        /// <exception cref="InvalidAudioDeviceException">
+        /// Occurs when the specified device is not available, or is in use by another program.
+        /// </exception>
+        /// <exception cref="InvalidAudioContextException">
+        /// Occurs when an audio context could not be created with the specified parameters.
+        /// </exception>
+        void CreateContext(string device, int freq, int refresh, bool sync)
+        {
+            if (String.IsNullOrEmpty(device)) throw new ArgumentNullException("device");
+            if (freq < 0) throw new ArgumentOutOfRangeException("freq", freq, "Should be greater than zero");
+            if (refresh < 0) throw new ArgumentOutOfRangeException("refresh", refresh, "Should be greater than zero");
+
+            device_handle = Alc.OpenDevice(device);
+            if (device_handle == IntPtr.Zero)
+                throw new InvalidAudioDeviceException();
+
+            List<int> attributes = new List<int>();
+            if (freq != 0)
+            {
+                attributes.Add((int)AlcContextAttributes.Frequency);
+                attributes.Add(freq);
+            }
+            if (refresh != 0)
+            {
+                attributes.Add((int)AlcContextAttributes.Refresh);
+                attributes.Add(refresh);
+            }
+            attributes.Add((int)AlcContextAttributes.Frequency);
+            attributes.Add(sync ? 1 : 0);
+
+            context_handle = Alc.CreateContext(device_handle, attributes.ToArray());
+            if (context_handle == IntPtr.Zero)
+            {
+                Alc.CloseDevice(device_handle);
+                throw new InvalidAudioContextException();
+            }
+        }
+
+
+        #endregion
+
+        #endregion
+
+        #region --- Public Members ---
+
+        #region public static string[] AvailableDevices
+
+        /// <summary>
+        /// Gets a System.String array containing all available audio devices.
+        /// </summary>
+        public static IEnumerable<string> AvailableDevices
+        {
+            get
+            {
+                return (IEnumerable<string>)available_devices;
+            }
+        }
+
+        #endregion
+
+        #endregion
+
+        #region --- IDisposable Members ---
+
+        public void Dispose()
+        {
+            this.Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        void Dispose(bool manual)
+        {
+            if (!disposed)
+            {
+                if (manual)
+                {
+                }
+                disposed = true;
+            }
+        }
+
+        ~AudioContext()
+        {
+            this.Dispose(false);
+        }
+
+        #endregion
+    }
+
+    #region --- Exceptions ---
+
+    public class InvalidAudioDeviceException : Exception
+    {
+        public InvalidAudioDeviceException() : base("The specified audio device does not exist or is tied up by another application.") { }
+    }
+
+    public class InvalidAudioContextException : Exception
+    {
+        public InvalidAudioContextException() : base("The audio context could not be created with the specified parameters.") { }
+    }
+
+    #endregion
+}