Opentk/Source/OpenTK/Audio/AudioContext.cs

629 lines
24 KiB
C#

#region --- License ---
/* Licensed under the MIT/X11 license.
* Copyright (c) 2006-2008 the OpenTK Team.
* This notice may not be removed from any source distribution.
* See license.txt for licensing details.
*/
#endregion
using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using OpenTK.Audio;
namespace OpenTK.Audio
{
/// <summary>
/// Provides methods to create and use an audio context.
/// </summary>
public sealed class AudioContext : IDisposable
{
#region --- Fields ---
bool disposed;
bool is_processing;
ContextHandle device_handle, context_handle;
bool context_exists;
string device_name;
static object audio_context_lock = new object();
static List<string> available_devices = new List<string>();
static Dictionary<ContextHandle, AudioContext> available_contexts = new Dictionary<ContextHandle, AudioContext>();
static bool openal_supported = true;
static Version version;
private enum Version
{
OpenAL10,
OpenAL11
}
#endregion
#region --- Constructors ---
#region static AudioContext()
/// <private />
/// <static />
/// <summary>
/// Runs before the actual class constructor, to load available devices.
/// </summary>
static AudioContext()
{
LoadAvailableDevices();
}
#endregion
#region public AudioContext()
/// <summary>Constructs a new AudioContext, using the default audio device.</summary>
/// <exception cref="NotSupportedException">Occurs when no audio devices are available.</exception>
public AudioContext()// : this(available_devices.Count > 0 ? available_devices[0] : null, 0, 0, false, 0) { }
{
if (!openal_supported)
throw new DllNotFoundException("openal32.dll");
CreateContext(null, 0, 0, false, 0);
}
#endregion
#if false
#region public AudioContext(string device)
/// <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.
/// devices.
/// </remarks>
public AudioContext(string device) : this(device, 0, 0, false, 0) { }
#endregion
#region public AudioContext(string device, int freq)
/// <summary>Constructs a new AudioContext, using the specified audio device and device parameters.</summary>
/// <param name="device">The name of the audio device to use.</param>
/// <param name="freq">Frequency for mixing output buffer, in units of Hz. Pass 0 for driver default.</param>
/// <remarks>
/// Use AudioContext.AvailableDevices to obtain a list of all available audio devices.
/// devices.
/// </remarks>
/// <see cref="AudioContext(string device, int freq, int refresh, bool sync, int maxEfxSends)"/>
public AudioContext(string device, int freq) : this(device, freq, 0, false, 0) { }
#endregion
#region public AudioContext(string device, int freq, int refresh)
/// <summary>Constructs a new AudioContext, using the specified audio device and device parameters.</summary>
/// <param name="device">The name of the audio device to use.</param>
/// <param name="freq">Frequency for mixing output buffer, in units of Hz. Pass 0 for driver default.</param>
/// <param name="refresh">Refresh intervals, in units of Hz. Pass 0 for driver default.</param>
/// <remarks>
/// Use AudioContext.AvailableDevices to obtain a list of all available audio devices.
/// devices.
/// </remarks>
/// <see cref="AudioContext(string device, int freq, int refresh, bool sync, int maxEfxSends)"/>
public AudioContext(string device, int freq, int refresh)
: this(device, freq, refresh, false, 0) { }
#endregion
#region public AudioContext(string device)
/// <summary>Constructs a new AudioContext, using the specified audio device and device parameters.</summary>
/// <param name="device">The name of the audio device to use.</param>
/// <param name="freq">Frequency for mixing output buffer, in units of Hz. Pass 0 for driver default.</param>
/// <param name="refresh">Refresh intervals, in units of Hz. Pass 0 for driver default.</param>
/// <param name="sync">Flag, indicating a synchronous context.</param>
/// <remarks>
/// Use AudioContext.AvailableDevices to obtain a list of all available audio devices.
/// devices.
/// </remarks>
/// <see cref="AudioContext(string device, int freq, int refresh, bool sync, int maxEfxSends)"/>
public AudioContext(string device, int freq, int refresh, bool sync)
: this(available_devices[0], freq, refresh, sync, 0) { }
#endregion
#region public AudioContext(string device, int freq, int refresh, bool sync, int maxSends)
/// <summary>Creates the audio context using the specified device and device parameters.</summary>
/// <param name="device">The device descriptor obtained through AudioContext.AvailableDevices.</param>
/// <param name="freq">Frequency for mixing output buffer, in units of Hz. Pass 0 for driver default.</param>
/// <param name="refresh">Refresh intervals, in units of Hz. Pass 0 for driver default.</param>
/// <param name="sync">Flag, indicating a synchronous context.</param>
/// <param name="maxSends">Number of auxilliary send slots for the EFX extensions. Can be 0 (use driver default) or higher.</param>
/// <exception cref="ArgumentNullException">Occurs when the device string is invalid.</exception>
/// <exception cref="ArgumentOutOfRangeException">Occurs when a specified parameter is invalid.</exception>
/// <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>
/// <exception cref="NotSupportedException">
/// Occurs when an AudioContext already exists.</exception>
/// <remarks>
/// <para>For maximum compatibility, you are strongly recommended to use the default constructor.</para>
/// <para>Multiple AudioContexts are not supported at this point.</para>
/// <para>
/// The number of auxilliary EFX sends depends on the audio hardware and drivers. Most Realtek devices, as well
/// as the Creative SB Live!, support 1 auxilliary send. Creative's Audigy and X-Fi series support 4 sends.
/// Values higher than supported will be clamped by the driver.
/// </para>
/// </remarks>
public AudioContext(string device, int freq, int refresh, bool sync, int maxSends)
{
CreateContext(device, freq, refresh, sync, maxSends);
}
#endregion
#endif
#endregion
#region --- Private Methods ---
#region static void LoadAvailableDevices()
/// <private />
/// <static />
/// <summary>
/// Loads all available audio devices into the available_devices array.
/// </summary>
/// <remarks>
/// Only called by the static AudioContext constructor.
/// </remarks>
static void LoadAvailableDevices()
{
lock (audio_context_lock)
{
if (available_devices.Count == 0)
{
try
{
Debug.WriteLine("Enumerating audio devices.");
Debug.Indent();
if (Alc.IsExtensionPresent(IntPtr.Zero, "ALC_ENUMERATION_EXT"))
{
version = Version.OpenAL11;
available_devices.AddRange(Alc.GetString(IntPtr.Zero, AlcGetStringList.DeviceSpecifier));
}
else
{
version = Version.OpenAL10;
Debug.Print("Device enumeration extension not available. Failed to enumerate devices.");
}
foreach (string s in available_devices)
Debug.WriteLine(s);
}
catch (DllNotFoundException e)
{
Debug.WriteLine(e.ToString());
openal_supported = false;
}
finally
{
Debug.Unindent();
}
}
}
}
#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, or null for the default device.</param>
/// <param name="freq">Frequency for mixing output buffer, in units of Hz. Pass 0 for driver default.</param>
/// <param name="refresh">Refresh intervals, in units of Hz. Pass 0 for driver default.</param>
/// <param name="sync">Flag, indicating a synchronous context.</param>
/// <param name="maxEfxSends">Number of auxilliary send slots for the EFX extensions. Can be 0 (use driver default) or higher.</param>
/// /// <exception cref="ArgumentOutOfRangeException">Occurs when a specified parameter is invalid.</exception>
/// <exception cref="AudioDeviceException">
/// Occurs when the specified device is not available, or is in use by another program.
/// </exception>
/// <exception cref="AudioDeviceException">
/// Occurs when an audio context could not be created with the specified parameters.
/// </exception>
/// <exception cref="NotSupportedException">
/// Occurs when an AudioContext already exists.</exception>
/// <remarks>
/// <para>For maximum compatibility, you are strongly recommended to use the default constructor.</para>
/// <para>Multiple AudioContexts are not supported at this point.</para>
/// <para>
/// The number of auxilliary EFX sends depends on the audio hardware and drivers. Most Realtek devices, as well
/// as the Creative SB Live!, support 1 auxilliary send. Creative's Audigy and X-Fi series support 4 sends.
/// Values higher than supported will be clamped by the driver.
/// </para>
/// </remarks>
void CreateContext(string device, int freq, int refresh, bool sync, int maxEfxSends)
{
if (version == Version.OpenAL11 && available_devices.Count == 0) // Version.OpenAL10 does not support device enumeration.
throw new NotSupportedException("No audio hardware is available.");
if (context_exists) throw new NotSupportedException("Multiple AudioContexts are not supported.");
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.");
if (maxEfxSends < 0) throw new ArgumentOutOfRangeException("maxEfxSends", maxEfxSends, "Should be greater than zero.");
if (!String.IsNullOrEmpty(device))
device_handle = Alc.OpenDevice(device);
if (device_handle == IntPtr.Zero)
Alc.OpenDevice(Alc.GetString(IntPtr.Zero, AlcGetString.DefaultDeviceSpecifier));
if (device_handle == IntPtr.Zero && available_devices.Count > 0)
device_handle = Alc.OpenDevice(available_devices[0]);
if (device_handle == IntPtr.Zero)
device_handle = Alc.OpenDevice(null);
if (device_handle == IntPtr.Zero)
throw new AudioDeviceException(String.Format("Audio device '{0}' does not exist or is tied up by another application.",
String.IsNullOrEmpty(device) ? "default" : device));
CheckForAlcErrors();
device_name = device;
// Build the attribute list
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);
if (maxEfxSends > 0)
{
throw new NotImplementedException();
//if (Alc.IsExtensionPresent(device_handle, "ALC_EXT_EFX"))
//attributes.Add((int)AlcContextAttributes.MaxAuxilliarySends);
//attributes.Add(maxEfxSends);
}
context_handle = Alc.CreateContext(device_handle, attributes.ToArray());
if (context_handle == IntPtr.Zero)
{
Alc.CloseDevice(device_handle);
throw new AudioContextException("The audio context could not be created with the specified parameters.");
}
CheckForAlcErrors();
// HACK: OpenAL SI on Linux/ALSA crashes on MakeCurrent. This hack avoids calling MakeCurrent when
// an old OpenAL version is detect - it may affect outdated OpenAL versions different than OpenAL SI,
// but it looks like a good compromise for now.
if (available_devices.Count > 0)
MakeCurrent();
CheckForAlcErrors();
//device_name = Alc.GetString(device_handle, AlcGetString.DeviceSpecifier);
//Debug.Print(device_name);
lock (audio_context_lock)
{
available_contexts.Add(this.context_handle, this);
context_exists = true;
}
}
#endregion
#region void CheckForAlcErrors()
void CheckForAlcErrors()
{
AlcError err = Alc.GetError(device_handle);
if (err != AlcError.NoError)
throw new AudioContextException(err.ToString());
}
#endregion
#region static void MakeCurrent(AudioContext context)
/// <private />
/// <summary>Makes the specified AudioContext current in the calling thread.</summary>
/// <param name="context">The OpenTK.Audio.AudioContext to make current, or null.</param>
/// <exception cref="ObjectDisposedException">
/// Occurs if this function is called after the AudioContext has been disposed.
/// </exception>
/// <exception cref="AudioContextException">
/// Occurs when the AudioContext could not be made current.
/// </exception>
static void MakeCurrent(AudioContext context)
{
lock (audio_context_lock)
{
if (!Alc.MakeContextCurrent(context != null ? (IntPtr)context.context_handle : IntPtr.Zero))
throw new AudioContextException(String.Format("ALC {0} error detected at {1}.",
Alc.GetError(context != null ? (IntPtr)context.context_handle : IntPtr.Zero).ToString(),
context != null ? context.ToString() : "null"));
}
}
#endregion
#region internal bool IsCurrent
/// <summary>
/// Gets or sets a System.Boolean indicating whether the AudioContext
/// is current.
/// </summary>
/// <remarks>
/// Only one AudioContext can be current in the application at any time,
/// <b>regardless of the number of threads</b>.
/// </remarks>
internal bool IsCurrent
{
get
{
lock (audio_context_lock)
{
if (available_contexts.Count == 0)
return false;
else
{
return AudioContext.CurrentContext == this;
}
}
}
set
{
if (value) AudioContext.MakeCurrent(this);
else AudioContext.MakeCurrent(null);
}
}
#endregion
#region IntPtr Device
IntPtr Device { get { return device_handle.Handle; } }
#endregion
#endregion
#region --- Public Members ---
#region internal void MakeCurrent()
/// <summary>Makes the AudioContext current in the calling thread.</summary>
/// <exception cref="ObjectDisposedException">
/// Occurs if this function is called after the AudioContext has been disposed.
/// </exception>
/// <exception cref="AudioContextException">
/// Occurs when the AudioContext could not be made current.
/// </exception>
/// <remarks>
/// Only one AudioContext can be current in the application at any time,
/// <b>regardless of the number of threads</b>.
/// </remarks>
public void MakeCurrent()
{
AudioContext.MakeCurrent(this);
}
#endregion
#region public bool IsProcessing
/// <summary>
/// Gets a System.Boolean indicating whether the AudioContext is
/// currently processing audio events.
/// </summary>
/// <seealso cref="Process"/>
/// <seealso cref="Suspend"/>
public bool IsProcessing
{
get { return is_processing; }
private set { is_processing = value; }
}
#endregion
#region public void Process
/// <summary>
/// Processes queued audio events.
/// </summary>
/// <remarks>
/// <para>
/// If AudioContext.IsSynchronized is true, this function will resume
/// the internal audio processing thread. If AudioContext.IsSynchronized is false,
/// you will need to call this function multiple times per second to process
/// audio events.
/// </para>
/// <para>
/// In some implementations this function may have no effect.
/// </para>
/// </remarks>
/// <exception cref="ObjectDisposedException">Occurs when this function is called after the AudioContext had been disposed.</exception>
/// <seealso cref="Suspend"/>
/// <seealso cref="IsSuspended"/>
/// <seealso cref="IsSynchronized"/>
public void Process()
{
if (disposed) throw new ObjectDisposedException(this.ToString());
Alc.ProcessContext(this.context_handle);
IsProcessing = true;
}
#endregion
#region public void Suspend
/// <summary>
/// Suspends processing of audio events.
/// </summary>
/// <remarks>
/// <para>
/// To avoid audio artifacts when calling this function, set audio gain to zero before
/// suspending an AudioContext.
/// </para>
/// <para>
/// In some implementations, it can be faster to suspend processing before changing
/// AudioContext state.
/// </para>
/// <para>
/// In some implementations this function may have no effect.
/// </para>
/// </remarks>
/// <exception cref="ObjectDisposedException">Occurs when this function is called after the AudioContext had been disposed.</exception>
/// <seealso cref="Process"/>
/// <seealso cref="IsSuspended"/>
/// <seealso cref="IsSynchronized"/>
public void Suspend()
{
if (disposed) throw new ObjectDisposedException(this.ToString());
Alc.SuspendContext(this.context_handle);
IsProcessing = false;
}
#endregion
#region public bool SupportsExtension(string extension)
/// <summary>
/// Checks whether the specified OpenAL extension is supported.
/// </summary>
/// <param name="extension">The name of the extension to check (e.g. "ALC_EXT_EFX").</param>
/// <returns>true if the extension is supported; false otherwise.</returns>
public bool SupportsExtension(string extension)
{
if (disposed) throw new ObjectDisposedException(this.GetType().FullName);
return Alc.IsExtensionPresent(this.Device, extension);
}
#endregion
#region public static AudioContext CurrentContext
/// <summary>
/// Gets the OpenTK.Audio.AudioContext which is current in the application.
/// </summary>
/// <remarks>
/// Only one AudioContext can be current in the application at any time,
/// <b>regardless of the number of threads</b>.
/// </remarks>
public static AudioContext CurrentContext
{
get
{
lock (audio_context_lock)
{
if (available_contexts.Count == 0)
return null;
else
{
AudioContext context;
AudioContext.available_contexts.TryGetValue(
(ContextHandle)Alc.GetCurrentContext(),
out context);
return context;
}
}
}
}
#endregion
#region public static string[] AvailableDevices
/// <summary>
/// Gets a System.String array containing all available audio devices.
/// </summary>
/// <remarks>This property allocates memory.</remarks>
public static string[] AvailableDevices
{
get
{
if (available_devices.Count == 0)
LoadAvailableDevices();
return available_devices.ToArray();
}
}
#endregion
#endregion
#region --- IDisposable Members ---
/// <summary>
/// Disposes of the AudioContext, cleaning up all resources consumed by it.
/// </summary>
public void Dispose()
{
this.Dispose(true);
GC.SuppressFinalize(this);
}
void Dispose(bool manual)
{
if (!disposed)
{
if (this.IsCurrent)
this.IsCurrent = false;
if (context_handle != IntPtr.Zero)
{
available_contexts.Remove(context_handle);
Alc.DestroyContext(context_handle);
}
if (device_handle != IntPtr.Zero)
Alc.CloseDevice(device_handle);
if (manual)
{
}
disposed = true;
}
}
~AudioContext()
{
this.Dispose(false);
}
#endregion
#region --- Overrides ---
public override int GetHashCode()
{
return base.GetHashCode();
}
public override bool Equals(object obj)
{
return base.Equals(obj);
}
public override string ToString()
{
return String.Format("{0} (handle: {1}, device: {2})",
this.device_name, this.context_handle, this.device_handle);
}
#endregion
}
}