mirror of
https://github.com/vcmi/vcmi.git
synced 2024-11-28 08:48:48 +02:00
fe1b16a7ec
- refactored CRandomGenerator (added util methods, improved method names) - usages of std::minstd_ran are replaced by CRandomGenerator (not in entire code base, C rand() usages are still not replaced) - refactored getArtSync method of CArtHandler -> now named pickRandomArtifact - fixed some compiler warnings - updated source code URL in VCMI spec
112 lines
2.8 KiB
C++
112 lines
2.8 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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typedef std::mt19937 TGenerator;
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typedef std::uniform_int_distribution<int> TIntDist;
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typedef std::uniform_real_distribution<double> TRealDist;
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typedef std::function<int()> TRandI;
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typedef std::function<double()> TRand;
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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 standard random API.
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class CRandomGenerator : boost::noncopyable
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{
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public:
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/// Seeds the generator with the current time by default.
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CRandomGenerator()
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{
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rand.seed(static_cast<unsigned long>(std::time(nullptr)));
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}
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void setSeed(int seed)
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{
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rand.seed(seed);
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}
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/// Generate several integer numbers within the same range.
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/// e.g.: auto a = gen.getIntRange(0,10); a(); a(); a();
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/// requires: lower <= upper
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TRandI getIntRange(int lower, int upper)
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{
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return boost::bind(TIntDist(lower, upper), boost::ref(rand));
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}
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/// Generates an integer between 0 and upper.
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/// requires: 0 <= upper
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int nextInt(int upper)
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{
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return getIntRange(0, upper)();
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}
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/// requires: lower <= upper
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int nextInt(int lower, int upper)
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{
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return getIntRange(lower, upper)();
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}
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/// Generates an integer between 0 and the maximum value it can hold.
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int nextInt()
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{
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return TIntDist()(rand);
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}
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/// Generate several double/real numbers within the same range.
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/// e.g.: auto a = gen.getDoubleRange(4.5,10.2); a(); a(); a();
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/// requires: lower <= upper
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TRand getDoubleRange(double lower, double upper)
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{
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return boost::bind(TRealDist(lower, upper), boost::ref(rand));
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}
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/// Generates a double between 0 and upper.
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/// requires: 0 <= upper
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double nextDouble(double upper)
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{
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return getDoubleRange(0, upper)();
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}
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/// requires: lower <= upper
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double nextDouble(double lower, double upper)
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{
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return getDoubleRange(lower, upper)();
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}
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/// Generates a double between 0.0 and 1.0.
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double nextDouble()
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{
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return TRealDist()(rand);
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}
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private:
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TGenerator rand;
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};
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namespace RandomGeneratorUtil
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{
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/// Gets an iterator to an element of a nonempty container randomly. Undefined behaviour if container is empty.
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template<typename Container>
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auto nextItem(const Container & container, CRandomGenerator & rand) -> decltype(std::begin(container))
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{
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assert(!container.empty());
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return std::next(container.begin(), rand.nextInt(container.size() - 1));
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}
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template<typename Container>
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auto nextItem(Container & container, CRandomGenerator & rand) -> decltype(std::begin(container))
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{
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assert(!container.empty());
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return std::next(container.begin(), rand.nextInt(container.size() - 1));
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}
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}
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