mirror of
https://github.com/vcmi/vcmi.git
synced 2024-11-24 08:32:34 +02:00
63 lines
1.4 KiB
C++
63 lines
1.4 KiB
C++
/*
|
|
* RNG.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
|
|
|
|
VCMI_LIB_NAMESPACE_BEGIN
|
|
|
|
namespace vstd
|
|
{
|
|
|
|
typedef std::function<int64_t()> TRandI64;
|
|
typedef std::function<double()> TRand;
|
|
|
|
class DLL_LINKAGE RNG
|
|
{
|
|
public:
|
|
|
|
virtual ~RNG() = default;
|
|
|
|
virtual TRandI64 getInt64Range(int64_t lower, int64_t upper) = 0;
|
|
|
|
virtual TRand getDoubleRange(double lower, double upper) = 0;
|
|
};
|
|
|
|
}
|
|
|
|
namespace RandomGeneratorUtil
|
|
{
|
|
template<typename Container>
|
|
auto nextItem(const Container & container, vstd::RNG & rand) -> decltype(std::begin(container))
|
|
{
|
|
assert(!container.empty());
|
|
return std::next(container.begin(), rand.getInt64Range(0, container.size() - 1)());
|
|
}
|
|
|
|
template<typename Container>
|
|
auto nextItem(Container & container, vstd::RNG & rand) -> decltype(std::begin(container))
|
|
{
|
|
assert(!container.empty());
|
|
return std::next(container.begin(), rand.getInt64Range(0, container.size() - 1)());
|
|
}
|
|
|
|
template<typename T>
|
|
void randomShuffle(std::vector<T> & container, vstd::RNG & rand)
|
|
{
|
|
int64_t n = (container.end() - container.begin());
|
|
|
|
for(int64_t i = n-1; i>0; --i)
|
|
{
|
|
std::swap(container.begin()[i],container.begin()[rand.getInt64Range(0, i)()]);
|
|
}
|
|
}
|
|
}
|
|
|
|
VCMI_LIB_NAMESPACE_END
|