Random.cpp

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// ----------------------------------------------------------------------------
// -                        CloudViewer: www.cloudViewer.org                  -
// ----------------------------------------------------------------------------
// Copyright (c) 2018-2024 www.cloudViewer.org
// SPDX-License-Identifier: MIT
// ----------------------------------------------------------------------------
 
#include "cloudViewer/utility/Random.h"
 
#include <Logging.h>
 
namespace cloudViewer {
namespace utility {
namespace random {
 
class RandomContext {
public:
    RandomContext(RandomContext const&) = delete;
    void operator=(RandomContext const&) = delete;
 
    static RandomContext& GetInstance() {
        static RandomContext instance;
        return instance;
    }
 
    void Seed(const int seed) {
        seed_ = seed;
        engine_ = std::mt19937(seed_);
    }
 
    std::mt19937* GetEngine() { return &engine_; }
 
    std::mutex* GetMutex() { return &mutex_; }
 
private:
    RandomContext() {
        // Randomly seed the seed by default.
        std::random_device rd;
        Seed(rd());
    }
    int seed_;
    std::mt19937 engine_;
    std::mutex mutex_;
};
 
void Seed(const int seed) { RandomContext::GetInstance().Seed(seed); }
 
std::mt19937* GetEngine() { return RandomContext::GetInstance().GetEngine(); }
 
std::mutex* GetMutex() { return RandomContext::GetInstance().GetMutex(); }
 
uint32_t RandUint32() {
    std::lock_guard<std::mutex> lock(*GetMutex());
    return (*GetEngine())();
}
 
}  // namespace random
}  // namespace utility
}  // namespace cloudViewer