misc.h

Go to the documentation of this file.

// g2o - General Graph Optimization
// Copyright (C) 2011 R. Kuemmerle, G. Grisetti, W. Burgard
// 
// g2o is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// g2o 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 Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#ifndef STUFF_MISC_H
#define STUFF_MISC_H

#include <cmath>

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

// @{

namespace g2o {

template <typename T>
inline T square(T x)
{
  return x*x;
}

template <typename T>
inline T hypot(T x, T y)
{
  return (T) (sqrt(x*x + y*y));
}

template <typename T>
inline T hypot_sqr(T x, T y)
{
  return x*x + y*y;
}

inline double deg2rad(double degree)
{
  return degree * 0.01745329251994329576;
}

inline double rad2deg(double rad)
{
  return rad * 57.29577951308232087721;
}

inline double normalize_theta(double theta)
{
  if (theta >= -M_PI && theta < M_PI)
    return theta;
  
  double multiplier = floor(theta / (2*M_PI));
  theta = theta - multiplier*2*M_PI;
  if (theta >= M_PI)
    theta -= 2*M_PI;
  if (theta < -M_PI)
    theta += 2*M_PI;

  return theta;
}

inline double inverse_theta(double th)
{
  return normalize_theta(th + M_PI);
}

inline double average_angle(double theta1, double theta2)
{
  double x, y;

  x = cos(theta1) + cos(theta2);
  y = sin(theta1) + sin(theta2);
  if(x == 0 && y == 0)
    return 0;
  else
    return std::atan2(y, x);
}

template <typename T>
inline int sign(T x)
{
  if (x > 0)
    return 1;
  else if (x < 0)
    return -1;
  else
    return 0;
}

template <typename T>
inline T clamp(T l, T x, T u) 
{
  if (x < l)
    return l;
  if (x > u)
    return u;
  return x;
}

template <typename T>
inline T wrap(T l, T x, T u) 
{
  T intervalWidth = u - l;
  while (x < l)
    x += intervalWidth;
  while (x > u)
    x -= intervalWidth;
  return x;
}

} // end namespace

// @}

#endif