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//
// Copyright 2014 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// random_utils:
// Helper functions for random number generation.
//
#include "random_utils.h"
#include <chrono>
#include <cstdlib>
namespace angle
{
// Seed from clock
RNG::RNG()
{
long long timeSeed = std::chrono::system_clock::now().time_since_epoch().count();
mGenerator.seed(static_cast<unsigned int>(timeSeed));
}
// Seed from fixed number.
RNG::RNG(unsigned int seed) : mGenerator(seed) {}
RNG::~RNG() {}
void RNG::reseed(unsigned int newSeed)
{
mGenerator.seed(newSeed);
}
bool RNG::randomBool(float probTrue)
{
std::bernoulli_distribution dist(probTrue);
return dist(mGenerator);
}
int RNG::randomInt()
{
std::uniform_int_distribution<int> intDistribution;
return intDistribution(mGenerator);
}
int RNG::randomIntBetween(int min, int max)
{
std::uniform_int_distribution<int> intDistribution(min, max);
return intDistribution(mGenerator);
}
unsigned int RNG::randomUInt()
{
std::uniform_int_distribution<unsigned int> uintDistribution;
return uintDistribution(mGenerator);
}
float RNG::randomFloat()
{
std::uniform_real_distribution<float> floatDistribution;
return floatDistribution(mGenerator);
}
float RNG::randomFloatBetween(float min, float max)
{
std::uniform_real_distribution<float> floatDistribution(min, max);
return floatDistribution(mGenerator);
}
float RNG::randomFloatNonnegative()
{
std::uniform_real_distribution<float> floatDistribution(0.0f,
std::numeric_limits<float>::max());
return floatDistribution(mGenerator);
}
float RNG::randomNegativeOneToOne()
{
return randomFloatBetween(-1.0f, 1.0f);
}
} // namespace angle