ranged_noise.hpp

//=======================================================================
// Copyright (c) 2014-2023 Baptiste Wicht
// Distributed under the terms of the MIT License.
// (See accompanying file LICENSE or copy at
//  http://opensource.org/licenses/MIT)
//=======================================================================

#pragma once

#include <ctime>

namespace etl {

template <typename G, typename T, typename E>
struct ranged_noise_binary_g_op {
    static constexpr bool linear      = true;  
    static constexpr bool thread_safe = false; 
    static constexpr bool desc_func   = true;  

    template <vector_mode_t V>
    static constexpr bool vectorizable = false;

    template <typename L, typename R>
    static constexpr bool gpu_computable = false;

    static constexpr int complexity() {
        return 1;
    }

    G& rand_engine; 

    ranged_noise_binary_g_op(G& rand_engine) : rand_engine(rand_engine) {
        //Nothing else to init
    }

    T apply(const T& x, E value) {
        std::normal_distribution<double> normal_distribution(0.0, 1.0);
        auto noise = std::bind(normal_distribution, rand_engine);

        if (x == 0.0 || x == value) {
            return x;
        } else {
            return x + noise();
        }
    }

    static std::string desc() noexcept {
        return "ranged_noise";
    }
};

template <typename T, typename E>
struct ranged_noise_binary_op {
    static constexpr bool linear      = true;  
    static constexpr bool thread_safe = false; 
    static constexpr bool desc_func   = true;  

    template <vector_mode_t V>
    static constexpr bool vectorizable = false;

    template <typename L, typename R>
    static constexpr bool gpu_computable = false;

    static T apply(const T& x, E value) {
        static random_engine rand_engine(std::time(nullptr));
        static std::normal_distribution<double> normal_distribution(0.0, 1.0);
        static auto noise = std::bind(normal_distribution, rand_engine);

        if (x == 0.0 || x == value) {
            return x;
        } else {
            return x + noise();
        }
    }

    static std::string desc() noexcept {
        return "ranged_noise";
    }
};

} //end of namespace etl