//
//  RotationAccumulator.h
//
//  Copyright 2015 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#include "RotationAccumulator.h"

#include <glm/gtx/quaternion.hpp>

void RotationAccumulator::add(const glm::quat& rotation, float weight) {
    // make sure both quaternions are on the same hyper-hemisphere before we add them linearly (lerp)
    _rotationSum += copysignf(weight, glm::dot(_rotationSum, rotation)) * rotation;
    ++_numRotations;
    _isDirty = true;
}

glm::quat RotationAccumulator::getAverage() {
    return (_numRotations > 0) ?  glm::normalize(_rotationSum) : glm::quat();
}

void RotationAccumulator::clear() {
    _rotationSum *= 0.0f;
    _numRotations = 0;
}

void RotationAccumulator::clearAndClean() { 
    clear();
    _isDirty = false;
}