BetweenQuaternionFactor.h

/***************************************************************************
 * libRSF - A Robust Sensor Fusion Library
 *
 * Copyright (C) 2023 Chair of Automation Technology / TU Chemnitz
 * For more information see https://www.tu-chemnitz.de/etit/proaut/libRSF
 *
 * libRSF is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * libRSF is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with libRSF.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Author: Tim Pfeifer (tim.pfeifer@etit.tu-chemnitz.de)
 ***************************************************************************/

/**
 * @file BetweenQuaternion.h
 * @author Tim Pfeifer
 * @date 03.12.2019
 * @brief A Factor that connects two quaternions with a body-frame rotation.
 * @copyright GNU Public License.
 *
 */

#ifndef BETWEENQUATERNIONFACTOR_H
#define BETWEENQUATERNIONFACTOR_H

#include "BaseFactor.h"
#include "../Geometry.h"

namespace libRSF
{
  template <typename ErrorType>
  class BetweenQuaternionFactor : public BaseFactor<ErrorType, true, false, 4, 4>
  {
    public:
      /** construct factor and store measurement */
      BetweenQuaternionFactor(ErrorType &Error, const Data &QuaternionMeasurement)
      {
        this->Error_ = Error;
        this->MeasurementVector_.resize(4);
        this->MeasurementVector_ = QuaternionMeasurement.getMean();
      }

      /** geometric error model */
      template <typename T>
      VectorT<T, 3> Evaluate(const T* const Quat1,
                                      const T* const Quat2,
                                      const Vector4 &Rotation) const
      {
        /** store as quaternion */
        Quaternion QuatRot(Rotation(3), Rotation(0), Rotation(1), Rotation(2)); /**< storage order is different from constructor! */

        /** map states */
        QuaternionRefConst<T> Q1(Quat1);
        QuaternionRefConst<T> Q2(Quat2);

        return RelativeQuaternionError<T>(Q1, Q2, QuatRot.template cast<T>());
      }

      /** combine probabilistic and geometric model */
      template <typename T, typename... ParamsType>
      bool operator()(const T* const Quat1,
                      const T* const Quat2,
                      ParamsType... Params) const
      {
        return this->Error_.template weight<T>(this->Evaluate(Quat1,
                                                              Quat2,
                                                              this->MeasurementVector_),
                                               Params...);
      }
  };

  /** compile time mapping from factor type enum to corresponding factor class */
  template<typename ErrorType>
  struct FactorTypeTranslator<FactorType::BetweenQuaternion, ErrorType> {using Type = BetweenQuaternionFactor<ErrorType>;};
}

#endif // BETWEENQUATERNIONFACTOR_H