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vcmi/lib/CRandomGenerator.h

83 lines
2.0 KiB
C++

/*
* CRandomGenerator.h, part of VCMI engine
*
* Authors: listed in file AUTHORS in main folder
*
* License: GNU General Public License v2.0 or later
* Full text of license available in license.txt file, in main folder
*
*/
#pragma once
#include <boost/version.hpp>
#include <boost/random/mersenne_twister.hpp>
#if BOOST_VERSION >= 104700
#include <boost/random/uniform_int_distribution.hpp>
#include <boost/random/uniform_real_distribution.hpp>
#else
#include <boost/random/uniform_int.hpp>
#include <boost/random/uniform_real.hpp>
#endif
#include <boost/random/variate_generator.hpp>
typedef boost::mt19937 TGenerator;
#if BOOST_VERSION >= 104700
typedef boost::random::uniform_int_distribution<int> TIntDist;
typedef boost::random::uniform_real_distribution<double> TRealDist;
#else
typedef boost::uniform_int<int> TIntDist;
typedef boost::uniform_real<double> TRealDist;
#endif
typedef boost::variate_generator<TGenerator &, TIntDist> TRandI;
typedef boost::variate_generator<TGenerator &, TRealDist> TRand;
/// The random generator randomly generates integers and real numbers("doubles") between
/// a given range. This is a header only class and mainly a wrapper for
/// convenient usage of the boost random API.
class CRandomGenerator
{
public:
/// Seeds the generator with the current time by default.
CRandomGenerator()
{
gen.seed(std::time(nullptr));
}
void seed(int value)
{
gen.seed(value);
}
/// Generate several integer numbers within the same range.
/// e.g.: auto a = gen.getRangeI(0,10); a(); a(); a();
TRandI getRangeI(int lower, int upper)
{
TIntDist range(lower, upper);
return TRandI(gen, range);
}
int getInteger(int lower, int upper)
{
return getRangeI(lower, upper)();
}
/// Generate several double/real numbers within the same range.
/// e.g.: auto a = gen.getRangeI(0,10); a(); a(); a();
TRand getRange(double lower, double upper)
{
TRealDist range(lower, upper);
return TRand(gen, range);
}
double getDouble(double lower, double upper)
{
return getRange(lower, upper)();
}
private:
TGenerator gen;
};