// g2o - General Graph Optimization
// Copyright (C) 2011 R. Kuemmerle, G. Grisetti, W. Burgard
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright notice,
//   this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
//   notice, this list of conditions and the following disclaimer in the
//   documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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#include "edge_se3_euler.h"

#include <iostream>

#include "g2o/core/factory.h"

using namespace Eigen;

namespace g2o {

/** conversion code from Euler angles */
static void jac_quat3_euler3(Eigen::Matrix<double, 6, 6, Eigen::ColMajor>& J,
                             const Isometry3& t) {
  Vector7 t0 = g2o::internal::toVectorQT(t);

  double delta = cst(1e-6);
  double idelta = 1 / (2 * delta);

  Vector7 ta;
  Vector7 tb;
  for (int i = 0; i < 6; i++) {
    ta = tb = t0;
    ta[i] -= delta;
    tb[i] += delta;
    Vector6 ea = g2o::internal::toVectorET(g2o::internal::fromVectorQT(ta));
    Vector6 eb = g2o::internal::toVectorET(g2o::internal::fromVectorQT(tb));
    J.col(i) = (eb - ea) * idelta;
  }
}

bool EdgeSE3Euler::read(std::istream& is) {
  Vector6 meas;
  for (int i = 0; i < 6; i++) is >> meas[i];
  Isometry3 transf = g2o::internal::fromVectorET(meas);
  Matrix<double, 6, 6, Eigen::ColMajor> infMatEuler;
  for (int i = 0; i < 6; i++)
    for (int j = i; j < 6; j++) {
      is >> infMatEuler(i, j);
      if (i != j) infMatEuler(j, i) = infMatEuler(i, j);
    }
  Matrix<double, 6, 6, Eigen::ColMajor> J;
  jac_quat3_euler3(J, transf);
  Matrix<double, 6, 6, Eigen::ColMajor> infMat =
      J.transpose() * infMatEuler * J;
  setMeasurement(transf);
  setInformation(infMat);
  return true;
}

bool EdgeSE3Euler::write(std::ostream& os) const {
  Vector6 meas = g2o::internal::toVectorET(_measurement);
  for (int i = 0; i < 6; i++) os << meas[i] << " ";

  Matrix<double, 6, 6, Eigen::ColMajor> J;
  jac_quat3_euler3(J, measurement());
  // HACK: invert the jacobian to simulate the inverse derivative
  J = J.inverse();
  Matrix<double, 6, 6, Eigen::ColMajor> infMatEuler =
      J.transpose() * information() * J;
  for (int i = 0; i < 6; i++)
    for (int j = i; j < 6; j++) {
      os << " " << infMatEuler(i, j);
    }
  return os.good();
}

}  // namespace g2o
