double ConeEffect::gain(FloatPoint3D sourcePosition, FloatPoint3D sourceOrientation, FloatPoint3D listenerPosition)
{
if (sourceOrientation.isZero() || ((m_innerAngle == 360.0) && (m_outerAngle == 360.0)))
return 1.0; // no cone specified - unity gain
// Normalized source-listener vector
FloatPoint3D sourceToListener = listenerPosition - sourcePosition;
sourceToListener.normalize();
FloatPoint3D normalizedSourceOrientation = sourceOrientation;
normalizedSourceOrientation.normalize();
// Angle between the source orientation vector and the source-listener vector
double dotProduct = sourceToListener.dot(normalizedSourceOrientation);
double angle = 180.0 * acos(dotProduct) / piDouble;
double absAngle = fabs(angle);
// Divide by 2.0 here since API is entire angle (not half-angle)
double absInnerAngle = fabs(m_innerAngle) / 2.0;
double absOuterAngle = fabs(m_outerAngle) / 2.0;
double gain = 1.0;
if (absAngle <= absInnerAngle)
// No attenuation
gain = 1.0;
else if (absAngle >= absOuterAngle)
// Max attenuation
gain = m_outerGain;
else {
// Between inner and outer cones
// inner -> outer, x goes from 0 -> 1
double x = (absAngle - absInnerAngle) / (absOuterAngle - absInnerAngle);
gain = (1.0 - x) + m_outerGain * x;
}
return gain;
}
void PannerNode::getAzimuthElevation(double* outAzimuth, double* outElevation)
{
// FIXME: we should cache azimuth and elevation (if possible), so we only re-calculate if a change has been made.
double azimuth = 0.0;
// Calculate the source-listener vector
FloatPoint3D listenerPosition = listener()->position();
FloatPoint3D sourceListener = m_position - listenerPosition;
if (sourceListener.isZero()) {
// degenerate case if source and listener are at the same point
*outAzimuth = 0.0;
*outElevation = 0.0;
return;
}
sourceListener.normalize();
// Align axes
FloatPoint3D listenerFront = listener()->orientation();
FloatPoint3D listenerUp = listener()->upVector();
FloatPoint3D listenerRight = listenerFront.cross(listenerUp);
listenerRight.normalize();
FloatPoint3D listenerFrontNorm = listenerFront;
listenerFrontNorm.normalize();
FloatPoint3D up = listenerRight.cross(listenerFrontNorm);
float upProjection = sourceListener.dot(up);
FloatPoint3D projectedSource = sourceListener - upProjection * up;
projectedSource.normalize();
azimuth = 180.0 * acos(projectedSource.dot(listenerRight)) / piDouble;
fixNANs(azimuth); // avoid illegal values
// Source in front or behind the listener
double frontBack = projectedSource.dot(listenerFrontNorm);
if (frontBack < 0.0)
azimuth = 360.0 - azimuth;
// Make azimuth relative to "front" and not "right" listener vector
if ((azimuth >= 0.0) && (azimuth <= 270.0))
azimuth = 90.0 - azimuth;
else
azimuth = 450.0 - azimuth;
// Elevation
double elevation = 90.0 - 180.0 * acos(sourceListener.dot(up)) / piDouble;
fixNANs(elevation); // avoid illegal values
if (elevation > 90.0)
elevation = 180.0 - elevation;
else if (elevation < -90.0)
elevation = -180.0 - elevation;
if (outAzimuth)
*outAzimuth = azimuth;
if (outElevation)
*outElevation = elevation;
}
