random_utils.cpp

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Author : Jamie Madill
Date : 2016-01-22 15:27:21
Hash : f83cbc65
Message : Use std::random functions for test and samples RNG. These standard functions are much more powerful than the C random() routines. Use them to improve the random utils, and use a class to clean things up further. This fixes a problem I was having using random_utils where I was having trouble generating random 32 bit unsigned integers. BUG=angleproject:1290 Change-Id: I5081764053d0667a4e323553b7dea531256aa778 Reviewed-on: https://chromium-review.googlesource.com/323440 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Tryjob-Request: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org>

util/random_utils.cpp

//
// Copyright (c) 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);
}

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::randomNegativeOneToOne()
{
    return randomFloatBetween(-1.0f, 1.0f);
}

}  // namespace angle

kc3-lang/angle/util/random_utils.cpp

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kc3-lang/angle /util/random_utils.cpp