private void PlatformApply3D(AudioListener listener, AudioEmitter emitter)
{
// If we have no voice then nothing to do.
if (_voice == null || SoundEffect.MasterVoice == null)
{
return;
}
// Convert from XNA Emitter to a SharpDX Emitter
var e = ToDXEmitter(emitter);
e.CurveDistanceScaler = SoundEffect.DistanceScale;
e.DopplerScaler = SoundEffect.DopplerScale;
e.ChannelCount = _effect._format.Channels;
//stereo channel
if (e.ChannelCount > 1)
{
e.ChannelRadius = 0;
e.ChannelAzimuths = _defaultChannelAzimuths;
}
// Convert from XNA Listener to a SharpDX Listener
var l = ToDXListener(listener);
// Number of channels in the sound being played.
// Not actually sure if XNA supported 3D attenuation of sterio sounds, but X3DAudio does.
var srcChannelCount = _effect._format.Channels;
// Number of output channels.
var dstChannelCount = SoundEffect.MasterVoice.VoiceDetails.InputChannelCount;
// XNA supports distance attenuation and doppler.
var dpsSettings = SoundEffect.Device3D.Calculate(l, e, CalculateFlags.Matrix | CalculateFlags.Doppler, srcChannelCount, dstChannelCount);
// Apply Volume settings (from distance attenuation) ...
_voice.SetOutputMatrix(SoundEffect.MasterVoice, srcChannelCount, dstChannelCount, dpsSettings.MatrixCoefficients, 0);
// Apply Pitch settings (from doppler) ...
_voice.SetFrequencyRatio(dpsSettings.DopplerFactor);
}
private Emitter ToDXEmitter(AudioEmitter emitter)
{
// Pulling out Vector properties for efficiency.
var pos = emitter.Position;
var vel = emitter.Velocity;
var forward = emitter.Forward;
var up = emitter.Up;
// From MSDN:
// X3DAudio uses a left-handed Cartesian coordinate system,
// with values on the x-axis increasing from left to right, on the y-axis from bottom to top,
// and on the z-axis from near to far.
// Azimuths are measured clockwise from a given reference direction.
//
// From MSDN:
// The XNA Framework uses a right-handed coordinate system,
// with the positive z-axis pointing toward the observer when the positive x-axis is pointing to the right,
// and the positive y-axis is pointing up.
//
// Programmer Notes:
// According to this description the z-axis (forward vector) is inverted between these two coordinate systems.
// Therefore, we need to negate the z component of any position/velocity values, and negate any forward vectors.
forward *= -1.0f;
pos.Z *= -1.0f;
vel.Z *= -1.0f;
if (_dxEmitter == null)
{
_dxEmitter = new Emitter();
}
_dxEmitter.Position = new RawVector3(pos.X, pos.Y, pos.Z);
_dxEmitter.Velocity = new RawVector3(vel.X, vel.Y, vel.Z);
_dxEmitter.OrientFront = new RawVector3(forward.X, forward.Y, forward.Z);
_dxEmitter.OrientTop = new RawVector3(up.X, up.Y, up.Z);
_dxEmitter.DopplerScaler = emitter.DopplerScale;
return(_dxEmitter);
}
private void PlatformApply3D(AudioListener listener, AudioEmitter emitter)
{
}