float AudioMixer::azimuthForSource(const PositionalAudioStream& streamToAdd, const AvatarAudioStream& listeningNodeStream,
const glm::vec3& relativePosition) {
glm::quat inverseOrientation = glm::inverse(listeningNodeStream.getOrientation());
// Compute sample delay for the two ears to create phase panning
glm::vec3 rotatedSourcePosition = inverseOrientation * relativePosition;
// project the rotated source position vector onto the XZ plane
rotatedSourcePosition.y = 0.0f;
static const float SOURCE_DISTANCE_THRESHOLD = 1e-30f;
if (glm::length2(rotatedSourcePosition) > SOURCE_DISTANCE_THRESHOLD) {
// produce an oriented angle about the y-axis
return glm::orientedAngle(glm::vec3(0.0f, 0.0f, -1.0f), glm::normalize(rotatedSourcePosition), glm::vec3(0.0f, -1.0f, 0.0f));
} else {
// there is no distance between listener and source - return no azimuth
return 0;
}
}
float computeAzimuth(const AvatarAudioStream& listeningNodeStream, const PositionalAudioStream& streamToAdd,
const glm::vec3& relativePosition) {
glm::quat inverseOrientation = glm::inverse(listeningNodeStream.getOrientation());
glm::vec3 rotatedSourcePosition = inverseOrientation * relativePosition;
// project the rotated source position vector onto the XZ plane
rotatedSourcePosition.y = 0.0f;
const float SOURCE_DISTANCE_THRESHOLD = 1e-30f;
float rotatedSourcePositionLength2 = glm::length2(rotatedSourcePosition);
if (rotatedSourcePositionLength2 > SOURCE_DISTANCE_THRESHOLD) {
// produce an oriented angle about the y-axis
glm::vec3 direction = rotatedSourcePosition * (1.0f / fastSqrtf(rotatedSourcePositionLength2));
float angle = fastAcosf(glm::clamp(-direction.z, -1.0f, 1.0f)); // UNIT_NEG_Z is "forward"
return (direction.x < 0.0f) ? -angle : angle;
} else {
// no azimuth if they are in same spot
return 0.0f;
}
}