orb_slam3_details/Thirdparty/DBoW2/DUtils/Random.cpp

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/*
* File: Random.cpp
* Project: DUtils library
* Author: Dorian Galvez-Lopez
* Date: April 2010
* Description: manages pseudo-random numbers
* License: see the LICENSE.txt file
*
*/
#include "Random.h"
#include "Timestamp.h"
#include <cstdlib>
using namespace std;
bool DUtils::Random::m_already_seeded = false;
void DUtils::Random::SeedRand(){
Timestamp time;
time.setToCurrentTime();
srand((unsigned)time.getFloatTime());
}
void DUtils::Random::SeedRandOnce()
{
if(!m_already_seeded)
{
DUtils::Random::SeedRand();
m_already_seeded = true;
}
}
void DUtils::Random::SeedRand(int seed)
{
srand(seed);
}
void DUtils::Random::SeedRandOnce(int seed)
{
if(!m_already_seeded)
{
DUtils::Random::SeedRand(seed);
m_already_seeded = true;
}
}
int DUtils::Random::RandomInt(int min, int max){
int d = max - min + 1;
return int(((double)rand()/((double)RAND_MAX + 1.0)) * d) + min;
}
// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------
DUtils::Random::UnrepeatedRandomizer::UnrepeatedRandomizer(int min, int max)
{
if(min <= max)
{
m_min = min;
m_max = max;
}
else
{
m_min = max;
m_max = min;
}
createValues();
}
// ---------------------------------------------------------------------------
DUtils::Random::UnrepeatedRandomizer::UnrepeatedRandomizer
(const DUtils::Random::UnrepeatedRandomizer& rnd)
{
*this = rnd;
}
// ---------------------------------------------------------------------------
int DUtils::Random::UnrepeatedRandomizer::get()
{
if(empty()) createValues();
DUtils::Random::SeedRandOnce();
int k = DUtils::Random::RandomInt(0, m_values.size()-1);
int ret = m_values[k];
m_values[k] = m_values.back();
m_values.pop_back();
return ret;
}
// ---------------------------------------------------------------------------
void DUtils::Random::UnrepeatedRandomizer::createValues()
{
int n = m_max - m_min + 1;
m_values.resize(n);
for(int i = 0; i < n; ++i) m_values[i] = m_min + i;
}
// ---------------------------------------------------------------------------
void DUtils::Random::UnrepeatedRandomizer::reset()
{
if((int)m_values.size() != m_max - m_min + 1) createValues();
}
// ---------------------------------------------------------------------------
DUtils::Random::UnrepeatedRandomizer&
DUtils::Random::UnrepeatedRandomizer::operator=
(const DUtils::Random::UnrepeatedRandomizer& rnd)
{
if(this != &rnd)
{
this->m_min = rnd.m_min;
this->m_max = rnd.m_max;
this->m_values = rnd.m_values;
}
return *this;
}
// ---------------------------------------------------------------------------