vpGaussRand.h

/*
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2025 by Inria. All rights reserved.
 *
 * This software 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 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See https://visp.inria.fr for more information.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
 * Inria at visp@inria.fr
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Description:
 * Generation of random number with uniform and normal probability density.
 */
 
#ifndef VP_GAUSSRAND_H
#define VP_GAUSSRAND_H
 
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpUniRand.h>
 
BEGIN_VISP_NAMESPACE
class VISP_EXPORT vpGaussRand
{
public:
  vpGaussRand() : m_rng(), m_mean(0), m_sigma(0), m_AlreadyDone(false), m_x2(0) { }

  vpGaussRand(double sigma_val, double mean_val, uint64_t noise_seed = 0)
    : m_rng(noise_seed), m_mean(mean_val), m_sigma(sigma_val), m_AlreadyDone(false), m_x2(0)
  { }

  void setSigmaMean(double sigma_val, double mean_val)
  {
    m_mean = mean_val;
    m_sigma = sigma_val;
  }

  void seed(uint64_t seed_val)
  {
    const uint64_t val_ull = 0x123465789ULL;
    m_rng.setSeed(seed_val, val_ull);
  }

  double operator()() { return (m_sigma * gaussianDraw()) + m_mean; }
 
private:
  double gaussianDraw();
 
  vpUniRand m_rng;
  double m_mean;
  double m_sigma;
  bool m_AlreadyDone;
  double m_x2;
};
END_VISP_NAMESPACE
#endif