text: /*****************************************************************************************
   *                                                                                       *
   * OpenSpace                                                                             *
   *                                                                                       *
   * Copyright (c) 2014-2020                                                               *
   *                                                                                       *
   * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
   * software and associated documentation files (the "Software"), to deal in the Software *
   * without restriction, including without limitation the rights to use, copy, modify,    *
   * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
   * permit persons to whom the Software is furnished to do so, subject to the following   *
   * conditions:                                                                           *
   *                                                                                       *
   * The above copyright notice and this permission notice shall be included in all copies *
   * or substantial portions of the Software.                                              *
   *                                                                                       *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
   * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
   * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
   * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
   * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
   * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
   ****************************************************************************************/
  
  #include <ghoul/misc/assert.h>
  
  namespace openspace::interaction {
  
  template <typename T>
  Interpolator<T>::Interpolator()
      : _transferFunction([](float t){ return t; })
  {}
  
  template <typename T>
  void Interpolator<T>::start() {
      _t = 0.f;
  }
  
  template <typename T>
  void Interpolator<T>::end() {
      _t = 1.f;
  }
  
  template <typename T>
  void Interpolator<T>::setDeltaTime(float deltaTime) {
      _scaledDeltaTime = deltaTime / _interpolationTime;
  }
  
  template <typename T>
  void Interpolator<T>::setTransferFunction(std::function<T(float)> transferFunction) {
      _transferFunction = std::move(transferFunction);
  }
  
  template <typename T>
  void Interpolator<T>::setInterpolationTime(float interpolationTime) {
      _interpolationTime = interpolationTime;
  }
  
  template <typename T>
  void Interpolator<T>::step() {
      _t += _scaledDeltaTime;
      _t = glm::clamp(_t, 0.0f, 1.0f);
  }
  
  template <typename T>
  float Interpolator<T>::deltaTimeScaled() const {
      return _scaledDeltaTime;
  }
  
  template <typename T>
  T Interpolator<T>::value() const {
      return _transferFunction(_t);
  }
  
  template <typename T>
  bool Interpolator<T>::isInterpolating() const {
      return (_t < 1.f) && (_t >= 0.f);
  }
  
  } // namespace openspace::interaction
  