/// \internal
/// <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="enableEfx">Indicates whether the EFX extension should be initialized, if present.</param>
/// <param name="efxAuxiliarySends">Requires EFX enabled. The number of desired Auxiliary Sends per source.</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="AudioContextException">
/// 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, bool enableEfx, MaxAuxiliarySends efxAuxiliarySends)
{
if (!AudioDeviceEnumerator.IsOpenALSupported)
{
throw new DllNotFoundException("openal32.dll");
}
if (AudioDeviceEnumerator.Version == AudioDeviceEnumerator.AlcVersion.Alc1_1 && AudioDeviceEnumerator.AvailablePlaybackDevices.Count == 0) // Alc 1.0 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 (!String.IsNullOrEmpty(device))
{
device_name = device;
device_handle = Alc.OpenDevice(device); // try to open device by name
}
if (device_handle == IntPtr.Zero)
{
device_name = "IntPtr.Zero (null string)";
device_handle = Alc.OpenDevice(null); // try to open unnamed default device
}
if (device_handle == IntPtr.Zero)
{
device_name = AudioContext.DefaultDevice;
device_handle = Alc.OpenDevice(AudioContext.DefaultDevice); // try to open named default device
}
if (device_handle == IntPtr.Zero)
{
device_name = "None";
throw new AudioDeviceException(String.Format("Audio device '{0}' does not exist or is tied up by another application.",
String.IsNullOrEmpty(device) ? "default" : device));
}
CheckErrors();
// 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.Sync);
attributes.Add(sync ? 1 : 0);
if (enableEfx && Alc.IsExtensionPresent(device_handle, "ALC_EXT_EFX"))
{
int num_slots;
switch (efxAuxiliarySends)
{
case MaxAuxiliarySends.One:
case MaxAuxiliarySends.Two:
case MaxAuxiliarySends.Three:
case MaxAuxiliarySends.Four:
num_slots = (int)efxAuxiliarySends;
break;
default:
case MaxAuxiliarySends.UseDriverDefault:
Alc.GetInteger(device_handle, AlcGetInteger.EfxMaxAuxiliarySends, 1, out num_slots);
break;
}
attributes.Add((int)AlcContextAttributes.EfxMaxAuxiliarySends);
attributes.Add(num_slots);
}
attributes.Add(0);
context_handle = Alc.CreateContext(device_handle, attributes.ToArray());
if (context_handle == ContextHandle.Zero)
{
Alc.CloseDevice(device_handle);
throw new AudioContextException("The audio context could not be created with the specified parameters.");
}
CheckErrors();
// 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 (AudioDeviceEnumerator.AvailablePlaybackDevices.Count > 0)
{
MakeCurrent();
}
CheckErrors();
device_name = Alc.GetString(device_handle, AlcGetString.DeviceSpecifier);
lock (audio_context_lock)
{
available_contexts.Add(this.context_handle, this);
context_exists = true;
}
}
private void CreateContext(string device, int freq, int refresh, bool sync, bool enableEfx, AudioContext.MaxAuxiliarySends efxAuxiliarySends)
{
if (!AudioDeviceEnumerator.IsOpenALSupported)
{
throw new DllNotFoundException("soft_oal.dll");
}
if (AudioDeviceEnumerator.Version == AudioDeviceEnumerator.AlcVersion.Alc1_1 && AudioDeviceEnumerator.AvailablePlaybackDevices.Count == 0)
{
throw new NotSupportedException("No audio hardware is available.");
}
if (this.context_exists)
{
throw new NotSupportedException("Multiple AudioContexts are not supported.");
}
if (freq < 0)
{
throw new ArgumentOutOfRangeException("freq", (object)freq, "Should be greater than zero.");
}
if (refresh < 0)
{
throw new ArgumentOutOfRangeException("refresh", (object)refresh, "Should be greater than zero.");
}
if (!string.IsNullOrEmpty(device))
{
this.device_name = device;
this.device_handle = Alc.OpenDevice(device);
}
if (this.device_handle == IntPtr.Zero)
{
this.device_name = "IntPtr.Zero (null string)";
this.device_handle = Alc.OpenDevice((string)null);
}
if (this.device_handle == IntPtr.Zero)
{
this.device_name = AudioContext.DefaultDevice;
this.device_handle = Alc.OpenDevice(AudioContext.DefaultDevice);
}
if (this.device_handle == IntPtr.Zero)
{
this.device_name = "None";
throw new AudioDeviceException(string.Format("Audio device '{0}' does not exist or is tied up by another application.", string.IsNullOrEmpty(device) ? (object)"default" : (object)device));
}
else
{
this.CheckErrors();
List <int> list = new List <int>();
if (freq != 0)
{
list.Add(4103);
list.Add(freq);
}
if (refresh != 0)
{
list.Add(4104);
list.Add(refresh);
}
list.Add(4105);
list.Add(sync ? 1 : 0);
if (enableEfx && Alc.IsExtensionPresent(this.device_handle, "ALC_EXT_EFX"))
{
int data;
switch (efxAuxiliarySends)
{
case AudioContext.MaxAuxiliarySends.One:
case AudioContext.MaxAuxiliarySends.Two:
case AudioContext.MaxAuxiliarySends.Three:
case AudioContext.MaxAuxiliarySends.Four:
data = (int)efxAuxiliarySends;
break;
default:
Alc.GetInteger(this.device_handle, AlcGetInteger.EfxMaxAuxiliarySends, 1, out data);
break;
}
list.Add(131075);
list.Add(data);
}
list.Add(0);
this.context_handle = Alc.CreateContext(this.device_handle, list.ToArray());
if (this.context_handle == ContextHandle.Zero)
{
Alc.CloseDevice(this.device_handle);
throw new AudioContextException("The audio context could not be created with the specified parameters.");
}
else
{
this.CheckErrors();
if (AudioDeviceEnumerator.AvailablePlaybackDevices.Count > 0)
{
this.MakeCurrent();
}
this.CheckErrors();
this.device_name = Alc.GetString(this.device_handle, AlcGetString.DeviceSpecifier);
lock (AudioContext.audio_context_lock)
{
AudioContext.available_contexts.Add(this.context_handle, this);
this.context_exists = true;
}
}
}
}
