/// \internal
/// <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 ? context.context_handle : ContextHandle.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"));
}
}
}
// Loads all available audio devices into the available_*_devices lists.
static AudioDeviceEnumerator()
{
IntPtr dummy_device = IntPtr.Zero;
ContextHandle dummy_context = ContextHandle.Zero;
try
{
Debug.WriteLine("Enumerating audio devices.");
Debug.Indent();
// need a dummy context for correct results
dummy_device = Alc.OpenDevice(null);
dummy_context = Alc.CreateContext(dummy_device, (int[])null);
bool dummy_success = Alc.MakeContextCurrent(dummy_context);
AlcError dummy_error = Alc.GetError(dummy_device);
if (!dummy_success || dummy_error != AlcError.NoError)
{
throw new AudioContextException("Failed to create dummy Context. Device (" + dummy_device.ToString() +
") Context (" + dummy_context.Handle.ToString() +
") MakeContextCurrent " + (dummy_success ? "succeeded" : "failed") +
", Alc Error (" + dummy_error.ToString() + ") " + Alc.GetString(IntPtr.Zero, (AlcGetString)dummy_error));
}
// Get a list of all known playback devices, using best extension available
if (Alc.IsExtensionPresent(IntPtr.Zero, "ALC_ENUMERATION_EXT"))
{
version = AlcVersion.Alc1_1;
if (Alc.IsExtensionPresent(IntPtr.Zero, "ALC_ENUMERATE_ALL_EXT"))
{
available_playback_devices.AddRange(Alc.GetString(IntPtr.Zero, AlcGetStringList.AllDevicesSpecifier));
default_playback_device = Alc.GetString(IntPtr.Zero, AlcGetString.DefaultAllDevicesSpecifier);
}
else
{
available_playback_devices.AddRange(Alc.GetString(IntPtr.Zero, AlcGetStringList.DeviceSpecifier));
default_playback_device = Alc.GetString(IntPtr.Zero, AlcGetString.DefaultDeviceSpecifier);
}
}
else
{
version = AlcVersion.Alc1_0;
Debug.Print("Device enumeration extension not available. Failed to enumerate playback devices.");
}
AlcError playback_err = Alc.GetError(dummy_device);
if (playback_err != AlcError.NoError)
{
throw new AudioContextException("Alc Error occured when querying available playback devices. " + playback_err.ToString());
}
// Get a list of all known recording devices, at least ALC_ENUMERATION_EXT is needed too
if (version == AlcVersion.Alc1_1 && Alc.IsExtensionPresent(IntPtr.Zero, "ALC_EXT_CAPTURE"))
{
available_recording_devices.AddRange(Alc.GetString(IntPtr.Zero, AlcGetStringList.CaptureDeviceSpecifier));
default_recording_device = Alc.GetString(IntPtr.Zero, AlcGetString.CaptureDefaultDeviceSpecifier);
}
else
{
Debug.Print("Capture extension not available. Failed to enumerate recording devices.");
}
AlcError record_err = Alc.GetError(dummy_device);
if (record_err != AlcError.NoError)
{
throw new AudioContextException("Alc Error occured when querying available recording devices. " + record_err.ToString());
}
#if DEBUG
Debug.WriteLine("Found playback devices:");
foreach (string s in available_playback_devices)
{
Debug.WriteLine(s);
}
Debug.WriteLine("Default playback device: " + default_playback_device);
Debug.WriteLine("Found recording devices:");
foreach (string s in available_recording_devices)
{
Debug.WriteLine(s);
}
Debug.WriteLine("Default recording device: " + default_recording_device);
#endif
}
catch (DllNotFoundException e)
{
Trace.WriteLine(e.ToString());
openal_supported = false;
}
catch (AudioContextException ace)
{
Trace.WriteLine(ace.ToString());
openal_supported = false;
}
finally
{
Debug.Unindent();
if (openal_supported)
{
try
{
// clean up the dummy context
Alc.MakeContextCurrent(ContextHandle.Zero);
if (dummy_context != ContextHandle.Zero && dummy_context.Handle != IntPtr.Zero)
{
Alc.DestroyContext(dummy_context);
}
if (dummy_device != IntPtr.Zero)
{
Alc.CloseDevice(dummy_device);
}
}
catch
{
openal_supported = false;
}
}
}
}