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135 lines
3.3 KiB
C++
135 lines
3.3 KiB
C++
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/*
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* CRandomGenerator.h, part of VCMI engine
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*
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* Authors: listed in file AUTHORS in main folder
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*
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* License: GNU General Public License v2.0 or later
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* Full text of license available in license.txt file, in main folder
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*
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*/
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#pragma once
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#include <boost/version.hpp>
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#include <boost/random/mersenne_twister.hpp>
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#if BOOST_VERSION >= 104700
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#include <boost/random/uniform_int_distribution.hpp>
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#include <boost/random/uniform_real_distribution.hpp>
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#else
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#include <boost/random/uniform_int.hpp>
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#include <boost/random/uniform_real.hpp>
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#endif
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#include <boost/random/variate_generator.hpp>
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typedef boost::mt19937 TGenerator;
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#if BOOST_VERSION >= 104700
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typedef boost::random::uniform_int_distribution<int> TIntDist;
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typedef boost::random::uniform_real_distribution<double> TRealDist;
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#else
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typedef boost::uniform_int<int> TIntDist;
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typedef boost::uniform_real<double> TRealDist;
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#endif
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typedef boost::variate_generator<TGenerator &, TIntDist> TRandI;
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typedef boost::variate_generator<TGenerator &, TRealDist> TRand;
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/**
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* The random generator randomly generates integers and real numbers("doubles") between
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* a given range. This is a header only class and mainly a wrapper for
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* convenient usage of the boost random API.
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*/
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class CRandomGenerator
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{
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public:
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/**
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* Constructor. Seeds the generator with the current time by default.
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*/
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CRandomGenerator()
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{
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gen.seed(std::time(nullptr));
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}
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/**
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* Seeds the generator with the given value.
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*
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* @param value the random seed
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*/
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void seed(int value)
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{
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gen.seed(value);
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}
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/**
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* Gets a generator which generates integers in the given range.
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*
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* Example how to use:
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* @code
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* TRandI rand = getRangeI(0, 10);
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* int a = rand(); // with the operator() the next value can be obtained
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* int b = rand(); // you can generate more values
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* @endcode
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*
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* @param lower the lower boundary
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* @param upper the upper boundary
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* @return the generator which can be used to generate integer numbers
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*/
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TRandI getRangeI(int lower, int upper)
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{
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TIntDist range(lower, upper);
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return TRandI(gen, range);
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}
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/**
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* Gets a integer in the given range. In comparison to getRangeI it's
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* a convenient method if you want to generate only one value in a given
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* range.
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*
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* @param lower the lower boundary
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* @param upper the upper boundary
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* @return the generated integer
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*/
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int getInteger(int lower, int upper)
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{
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return getRangeI(lower, upper)();
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}
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/**
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* Gets a generator which generates doubles in the given range.
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*
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* Example how to use:
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* @code
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* TRand rand = getRange(23.56, 32.10);
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* double a = rand(); // with the operator() the next value can be obtained
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* double b = rand(); // you can generate more values
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* @endcode
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*
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* @param lower the lower boundary
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* @param upper the upper boundary
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* @return the generated double
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*/
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TRand getRange(double lower, double upper)
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{
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TRealDist range(lower, upper);
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return TRand(gen, range);
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}
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/**
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* Gets a double in the given range. In comparison to getRange it's
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* a convenient method if you want to generate only one value in a given
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* range.
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*
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* @param lower the lower boundary
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* @param upper the upper boundary
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* @return the generated double
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*/
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double getDouble(double lower, double upper)
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{
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return getRange(lower, upper)();
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}
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private:
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/** The actual boost random generator. */
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TGenerator gen;
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};
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