RandomNumbers.h

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/* Author: Ioan Sucan, Jonathan Gammell */

#ifndef OMPL_UTIL_RANDOM_NUMBERS_
#define OMPL_UTIL_RANDOM_NUMBERS_

#include <memory>
#include <random>
#include <cassert>
#include <cstdint>

#include "ompl/config.h"
#if OMPL_HAVE_EIGEN3
#include "ompl/util/ProlateHyperspheroid.h"
#endif

namespace ompl
{
    class RNG
    {
    public:

        RNG();

        RNG(std::uint_fast32_t localSeed);

        double uniform01()
        {
            return uniDist_(generator_);
        }

        double uniformReal(double lower_bound, double upper_bound)
        {
            assert(lower_bound <= upper_bound);
            return (upper_bound - lower_bound) * uniDist_(generator_) + lower_bound;
        }

        int uniformInt(int lower_bound, int upper_bound)
        {
            int r = (int)floor(uniformReal((double)lower_bound, (double)(upper_bound) + 1.0));
            return (r > upper_bound) ? upper_bound : r;
        }

        bool uniformBool()
        {
            return uniDist_(generator_) <= 0.5;
        }

        double gaussian01()
        {
            return normalDist_(generator_);
        }

        double gaussian(double mean, double stddev)
        {
            return normalDist_(generator_) * stddev + mean;
        }

        double halfNormalReal(double r_min, double r_max, double focus = 3.0);

        int    halfNormalInt(int r_min, int r_max, double focus = 3.0);

        void   quaternion(double value[4]);

        void   eulerRPY(double value[3]);

        static void setSeed(std::uint_fast32_t seed);

        static std::uint_fast32_t getSeed();

        void setLocalSeed(std::uint_fast32_t localSeed);

        std::uint_fast32_t getLocalSeed() const
        {
            return localSeed_;
        }

        void uniformNormalVector(unsigned int n, double value[]);

        void uniformInBall(double r, unsigned int n, double value[]);

#if OMPL_HAVE_EIGEN3

        void uniformProlateHyperspheroidSurface(const std::shared_ptr<const ProlateHyperspheroid> &phsPtr, double value[]);

        void uniformProlateHyperspheroid(const std::shared_ptr<const ProlateHyperspheroid> &phsPtr, double value[]);
#endif

    private:
        class SphericalData;

        std::uint_fast32_t               localSeed_;
        std::mt19937                     generator_;
        std::uniform_real_distribution<> uniDist_;
        std::normal_distribution<>       normalDist_;
        //A structure holding boost::uniform_on_sphere distributions and the associated boost::variate_generators for various dimension
        std::shared_ptr<SphericalData>   sphericalDataPtr_;

    };
}

#endif