#define X3DAUDIO_CALCULATE_ZEROCENTER 0x00010000 // do not position to front center speaker, signal positioned to remaining speakers instead, front center destination channel will be zero in returned matrix coefficient table, valid only for matrix calculations with final mix formats that have a front center channel
#define X3DAUDIO_CALCULATE_REDIRECT_TO_LFE 0x00020000 // apply equal mix of all source channels to LFE destination channel, valid only for matrix calculations with sources that have no LFE channel and final mix formats that have an LFE channel
// A piecewise curve made up of linear segments used to
// define DSP behaviour with respect to normalized distance.
//
// Note that curve point distances are normalized within [0.0f, 1.0f].
// X3DAUDIO_EMITTER.CurveDistanceScaler must be used to scale the
// normalized distances to user-defined world units.
// For distances beyond CurveDistanceScaler * 1.0f,
// pPoints[PointCount-1].DSPSetting is used as the DSP setting.
//
// All distance curve spans must be such that:
// pPoints[k-1].DSPSetting + ((pPoints[k].DSPSetting-pPoints[k-1].DSPSetting) / (pPoints[k].Distance-pPoints[k-1].Distance)) * (pPoints[k].Distance-pPoints[k-1].Distance) != NAN or infinite values
// For all points in the distance curve where 1 <= k < PointCount.
typedefstructX3DAUDIO_DISTANCE_CURVE
{
X3DAUDIO_DISTANCE_CURVE_POINT*pPoints;// distance curve point array, must have at least PointCount elements with no duplicates and be sorted in ascending order with respect to Distance
UINT32PointCount;// number of distance curve points, must be >= 2 as all distance curves must have at least two endpoints, defining DSP settings at 0.0f and 1.0f normalized distance
// Specifies directionality for a listener or single-channel emitter by
// modifying DSP behaviour with respect to its front orientation.
// This is modeled using two sound cones: an inner cone and an outer cone.
// On/within the inner cone, DSP settings are scaled by the inner values.
// On/beyond the outer cone, DSP settings are scaled by the outer values.
// If on both the cones, DSP settings are scaled by the inner values only.
// Between the two cones, the scaler is linearly interpolated between the
// inner and outer values. Set both cone angles to 0 or X3DAUDIO_2PI for
// omnidirectionality using only the outer or inner values respectively.
typedefstructX3DAUDIO_CONE
{
FLOAT32InnerAngle;// inner cone angle in radians, must be within [0.0f, X3DAUDIO_2PI]
FLOAT32OuterAngle;// outer cone angle in radians, must be within [InnerAngle, X3DAUDIO_2PI]
FLOAT32InnerVolume;// volume level scaler on/within inner cone, used only for matrix calculations, must be within [0.0f, 2.0f] when used
FLOAT32OuterVolume;// volume level scaler on/beyond outer cone, used only for matrix calculations, must be within [0.0f, 2.0f] when used
FLOAT32InnerLPF;// LPF (both direct and reverb paths) coefficient subtrahend on/within inner cone, used only for LPF (both direct and reverb paths) calculations, must be within [0.0f, 1.0f] when used
FLOAT32OuterLPF;// LPF (both direct and reverb paths) coefficient subtrahend on/beyond outer cone, used only for LPF (both direct and reverb paths) calculations, must be within [0.0f, 1.0f] when used
FLOAT32InnerReverb;// reverb send level scaler on/within inner cone, used only for reverb calculations, must be within [0.0f, 2.0f] when used
FLOAT32OuterReverb;// reverb send level scaler on/beyond outer cone, used only for reverb calculations, must be within [0.0f, 2.0f] when used
// The cone is directed by the listener's front orientation.
typedefstructX3DAUDIO_LISTENER
{
X3DAUDIO_VECTOROrientFront;// orientation of front direction, used only for matrix and delay calculations or listeners with cones for matrix, LPF (both direct and reverb paths), and reverb calculations, must be normalized when used
X3DAUDIO_VECTOROrientTop;// orientation of top direction, used only for matrix and delay calculations, must be orthonormal with OrientFront when used
X3DAUDIO_VECTORPosition;// position in user-defined world units, does not affect Velocity
X3DAUDIO_VECTORVelocity;// velocity vector in user-defined world units/second, used only for doppler calculations, does not affect Position
X3DAUDIO_CONE*pCone;// sound cone, used only for matrix, LPF (both direct and reverb paths), and reverb calculations, NULL specifies omnidirectionality
}X3DAUDIO_LISTENER,*LPX3DAUDIO_LISTENER;
// Emitter:
// Defines a 3D audio source, divided into two classifications:
//
// Single-point -- For use with single-channel sounds.
// Positioned at the emitter base, i.e. the channel radius
// and azimuth are ignored if the number of channels == 1.
//
// May be omnidirectional or directional using a cone.
// The cone originates from the emitter base position,
// and is directed by the emitter's front orientation.
//
// Multi-point -- For use with multi-channel sounds.
// Each non-LFE channel is positioned using an
// azimuth along the channel radius with respect to the
// front orientation vector in the plane orthogonal to the
// top orientation vector. An azimuth of X3DAUDIO_2PI
// specifies a channel is an LFE. Such channels are
// positioned at the emitter base and are calculated
// with respect to pLFECurve only, never pVolumeCurve.
//
// Multi-point emitters are always omnidirectional,
// i.e. the cone is ignored if the number of channels > 1.
//
// Note that many properties are shared among all channel points,
// locking certain behaviour with respect to the emitter base position.
// For example, doppler shift is always calculated with respect to the
// emitter base position and so is constant for all its channel points.
// Distance curve calculations are also with respect to the emitter base
// position, with the curves being calculated independently of each other.
// For instance, volume and LFE calculations do not affect one another.
typedefstructX3DAUDIO_EMITTER
{
X3DAUDIO_CONE*pCone;// sound cone, used only with single-channel emitters for matrix, LPF (both direct and reverb paths), and reverb calculations, NULL specifies omnidirectionality
X3DAUDIO_VECTOROrientFront;// orientation of front direction, used only for emitter angle calculations or with multi-channel emitters for matrix calculations or single-channel emitters with cones for matrix, LPF (both direct and reverb paths), and reverb calculations, must be normalized when used
X3DAUDIO_VECTOROrientTop;// orientation of top direction, used only with multi-channel emitters for matrix calculations, must be orthonormal with OrientFront when used
X3DAUDIO_VECTORPosition;// position in user-defined world units, does not affect Velocity
X3DAUDIO_VECTORVelocity;// velocity vector in user-defined world units/second, used only for doppler calculations, does not affect Position
FLOAT32InnerRadius;// inner radius, must be within [0.0f, FLT_MAX]
FLOAT32InnerRadiusAngle;// inner radius angle, must be within [0.0f, X3DAUDIO_PI/4.0)
UINT32ChannelCount;// number of sound channels, must be > 0
FLOAT32ChannelRadius;// channel radius, used only with multi-channel emitters for matrix calculations, must be >= 0.0f when used
FLOAT32*pChannelAzimuths;// channel azimuth array, used only with multi-channel emitters for matrix calculations, contains positions of each channel expressed in radians along the channel radius with respect to the front orientation vector in the plane orthogonal to the top orientation vector, or X3DAUDIO_2PI to specify an LFE channel, must have at least ChannelCount elements, all within [0.0f, X3DAUDIO_2PI] when used
X3DAUDIO_DISTANCE_CURVE*pVolumeCurve;// volume level distance curve, used only for matrix calculations, NULL specifies a default curve that conforms to the inverse square law, calculated in user-defined world units with distances <= CurveDistanceScaler clamped to no attenuation
X3DAUDIO_DISTANCE_CURVE*pLFECurve;// LFE level distance curve, used only for matrix calculations, NULL specifies a default curve that conforms to the inverse square law, calculated in user-defined world units with distances <= CurveDistanceScaler clamped to no attenuation
X3DAUDIO_DISTANCE_CURVE*pLPFDirectCurve;// LPF direct-path coefficient distance curve, used only for LPF direct-path calculations, NULL specifies the default curve: [0.0f,1.0f], [1.0f,0.75f]
X3DAUDIO_DISTANCE_CURVE*pLPFReverbCurve;// LPF reverb-path coefficient distance curve, used only for LPF reverb-path calculations, NULL specifies the default curve: [0.0f,0.75f], [1.0f,0.75f]
X3DAUDIO_DISTANCE_CURVE*pReverbCurve;// reverb send level distance curve, used only for reverb calculations, NULL specifies the default curve: [0.0f,1.0f], [1.0f,0.0f]
FLOAT32CurveDistanceScaler;// curve distance scaler, used to scale normalized distance curves to user-defined world units and/or exaggerate their effect, used only for matrix, LPF (both direct and reverb paths), and reverb calculations, must be within [FLT_MIN, FLT_MAX] when used
FLOAT32DopplerScaler;// doppler shift scaler, used to exaggerate doppler shift effect, used only for doppler calculations, must be within [0.0f, FLT_MAX] when used
}X3DAUDIO_EMITTER,*LPX3DAUDIO_EMITTER;
// DSP settings:
// Receives results from a call to X3DAudioCalculate to be sent
// to the low-level audio rendering API for 3D signal processing.
//
// The user is responsible for allocating the matrix coefficient table,
// delay time array, and initializing the channel counts when used.
typedefstructX3DAUDIO_DSP_SETTINGS
{
FLOAT32*pMatrixCoefficients;// [inout] matrix coefficient table, receives an array representing the volume level used to send from source channel S to destination channel D, stored as pMatrixCoefficients[SrcChannelCount * D + S], must have at least SrcChannelCount*DstChannelCount elements
FLOAT32*pDelayTimes;// [inout] delay time array, receives delays for each destination channel in milliseconds, must have at least DstChannelCount elements (stereo final mix only)
UINT32SrcChannelCount;// [in] number of source channels, must equal number of channels in respective emitter
UINT32DstChannelCount;// [in] number of destination channels, must equal number of channels of the final mix
FLOAT32DopplerFactor;// [out] doppler shift factor, scales resampler ratio for doppler shift effect, where the effective frequency = DopplerFactor * original frequency
FLOAT32EmitterToListenerAngle;// [out] emitter-to-listener interior angle, expressed in radians with respect to the emitter's front orientation
FLOAT32EmitterToListenerDistance;// [out] distance in user-defined world units from the emitter base to listener position, always calculated
FLOAT32EmitterVelocityComponent;// [out] component of emitter velocity vector projected onto emitter->listener vector in user-defined world units/second, calculated only for doppler
FLOAT32ListenerVelocityComponent;// [out] component of listener velocity vector projected onto emitter->listener vector in user-defined world units/second, calculated only for doppler
