rigid_transform.h

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/*
 * Copyright 2016 The Cartographer Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CARTOGRAPHER_TRANSFORM_RIGID_TRANSFORM_H_
#define CARTOGRAPHER_TRANSFORM_RIGID_TRANSFORM_H_

#include <cmath>
#include <iostream>
#include <string>

#include "Eigen/Core"
#include "Eigen/Geometry"
#include "absl/strings/substitute.h"
#include "cartographer/common/lua_parameter_dictionary.h"
#include "cartographer/common/math.h"
#include "cartographer/common/port.h"

namespace cartographer {
namespace transform {

template <typename FloatType>
class Rigid2 {
 public:
  using Vector = Eigen::Matrix<FloatType, 2, 1>;
  using Rotation2D = Eigen::Rotation2D<FloatType>;

  Rigid2() : translation_(Vector::Zero()), rotation_(Rotation2D::Identity()) {}
  Rigid2(const Vector& translation, const Rotation2D& rotation)
      : translation_(translation), rotation_(rotation) {}
  Rigid2(const Vector& translation, const double rotation)
      : translation_(translation), rotation_(rotation) {}

  static Rigid2 Rotation(const double rotation) {
    return Rigid2(Vector::Zero(), rotation);
  }

  static Rigid2 Rotation(const Rotation2D& rotation) {
    return Rigid2(Vector::Zero(), rotation);
  }

  static Rigid2 Translation(const Vector& vector) {
    return Rigid2(vector, Rotation2D::Identity());
  }

  static Rigid2<FloatType> Identity() { return Rigid2<FloatType>(); }

  template <typename OtherType>
  Rigid2<OtherType> cast() const {
    return Rigid2<OtherType>(translation_.template cast<OtherType>(),
                             rotation_.template cast<OtherType>());
  }

  const Vector& translation() const { return translation_; }

  Rotation2D rotation() const { return rotation_; }

  double normalized_angle() const {
    return common::NormalizeAngleDifference(rotation().angle());
  }

  Rigid2 inverse() const {
    const Rotation2D rotation = rotation_.inverse();
    const Vector translation = -(rotation * translation_);
    return Rigid2(translation, rotation);
  }

  std::string DebugString() const {
    return absl::Substitute("{ t: [$0, $1], r: [$2] }", translation().x(),
                            translation().y(), rotation().angle());
  }

 private:
  Vector translation_;
  Rotation2D rotation_;
};

template <typename FloatType>
Rigid2<FloatType> operator*(const Rigid2<FloatType>& lhs,
                            const Rigid2<FloatType>& rhs) {
  return Rigid2<FloatType>(
      lhs.rotation() * rhs.translation() + lhs.translation(),
      lhs.rotation() * rhs.rotation());
}

template <typename FloatType>
typename Rigid2<FloatType>::Vector operator*(
    const Rigid2<FloatType>& rigid,
    const typename Rigid2<FloatType>::Vector& point) {
  return rigid.rotation() * point + rigid.translation();
}

// This is needed for gmock.
template <typename T>
std::ostream& operator<<(std::ostream& os,
                         const cartographer::transform::Rigid2<T>& rigid) {
  os << rigid.DebugString();
  return os;
}

using Rigid2d = Rigid2<double>;
using Rigid2f = Rigid2<float>;

template <typename FloatType>
class Rigid3 {
 public:
  using Vector = Eigen::Matrix<FloatType, 3, 1>;
  using Quaternion = Eigen::Quaternion<FloatType>;
  using AngleAxis = Eigen::AngleAxis<FloatType>;

  Rigid3() : translation_(Vector::Zero()), rotation_(Quaternion::Identity()) {}
  Rigid3(const Vector& translation, const Quaternion& rotation)
      : translation_(translation), rotation_(rotation) {}
  Rigid3(const Vector& translation, const AngleAxis& rotation)
      : translation_(translation), rotation_(rotation) {}

  static Rigid3 Rotation(const AngleAxis& angle_axis) {
    return Rigid3(Vector::Zero(), Quaternion(angle_axis));
  }

  static Rigid3 Rotation(const Quaternion& rotation) {
    return Rigid3(Vector::Zero(), rotation);
  }

  static Rigid3 Translation(const Vector& vector) {
    return Rigid3(vector, Quaternion::Identity());
  }

  static Rigid3 FromArrays(const std::array<FloatType, 4>& rotation,
                           const std::array<FloatType, 3>& translation) {
    return Rigid3(Eigen::Map<const Vector>(translation.data()),
                  Eigen::Quaternion<FloatType>(rotation[0], rotation[1],
                                               rotation[2], rotation[3]));
  }

  static Rigid3<FloatType> Identity() { return Rigid3<FloatType>(); }

  template <typename OtherType>
  Rigid3<OtherType> cast() const {
    return Rigid3<OtherType>(translation_.template cast<OtherType>(),
                             rotation_.template cast<OtherType>());
  }

  const Vector& translation() const { return translation_; }
  const Quaternion& rotation() const { return rotation_; }

  Rigid3 inverse() const {
    const Quaternion rotation = rotation_.conjugate();
    const Vector translation = -(rotation * translation_);
    return Rigid3(translation, rotation);
  }

  std::string DebugString() const {
    return absl::Substitute("{ t: [$0, $1, $2], q: [$3, $4, $5, $6] }",
                            translation().x(), translation().y(),
                            translation().z(), rotation().w(), rotation().x(),
                            rotation().y(), rotation().z());
  }

  bool IsValid() const {
    return !std::isnan(translation_.x()) && !std::isnan(translation_.y()) &&
           !std::isnan(translation_.z()) &&
           std::abs(FloatType(1) - rotation_.norm()) < FloatType(1e-3);
  }

 private:
  Vector translation_;
  Quaternion rotation_;
};

template <typename FloatType>
Rigid3<FloatType> operator*(const Rigid3<FloatType>& lhs,
                            const Rigid3<FloatType>& rhs) {
  return Rigid3<FloatType>(
      lhs.rotation() * rhs.translation() + lhs.translation(),
      (lhs.rotation() * rhs.rotation()).normalized());
}

template <typename FloatType>
typename Rigid3<FloatType>::Vector operator*(
    const Rigid3<FloatType>& rigid,
    const typename Rigid3<FloatType>::Vector& point) {
  return rigid.rotation() * point + rigid.translation();
}

// This is needed for gmock.
template <typename T>
std::ostream& operator<<(std::ostream& os,
                         const cartographer::transform::Rigid3<T>& rigid) {
  os << rigid.DebugString();
  return os;
}

using Rigid3d = Rigid3<double>;
using Rigid3f = Rigid3<float>;

// Converts (roll, pitch, yaw) to a unit length quaternion. Based on the URDF
// specification http://wiki.ros.org/urdf/XML/joint.
Eigen::Quaterniond RollPitchYaw(double roll, double pitch, double yaw);

// Returns an transform::Rigid3d given a 'dictionary' containing 'translation'
// (x, y, z) and 'rotation' which can either we an array of (roll, pitch, yaw)
// or a dictionary with (w, x, y, z) values as a quaternion.
Rigid3d FromDictionary(common::LuaParameterDictionary* dictionary);

}  // namespace transform
}  // namespace cartographer

#endif  // CARTOGRAPHER_TRANSFORM_RIGID_TRANSFORM_H_