Purple Rain Drops in C++ SFML

#include <SFML/Graphics.hpp>
#include <vector>
#include <random>
#include <cmath>

const int Width = 1080;
const int Heigth = 720;

class RainDrop {
private:
    double _x, _y, _z;
    int ceiling=Heigth;
    double yspeed=0, gravity=0;

public:

    RainDrop() : _x(0), _y(0), _z(1),gravity(0) {};
    RainDrop(double x, double y, double z, double G = 0) : _x(x), _y(y), _z(z) { SetGravity(G); };
    void Show(sf::RenderWindow & window) {
        using namespace sf;
        RectangleShape Drop;
        Drop.setFillColor(Color::Magenta);
        Drop.setSize(Vector2f(_z,2*_z));
        Drop.setPosition(_x, _y);
        window.draw(Drop);
    }
    bool Fall() {
        if (_y > ceiling) {
            yspeed = 0;
            return 1;
        }
        yspeed -= gravity;
        _y -= yspeed;
        return 0;

    }
    void SetGravity(double Gravity){
        gravity = Gravity * (std::exp(_z/2)) / 100;
    }
    void SetCoordX(double x) {
        _x = x;
    }
    void SetCoordY(double y) {
        _y = y;
    }

};

int main()
{


    sf::RenderWindow window(sf::VideoMode(Width, Heigth), "SFML works!");
    window.setFramerateLimit(60);

    std::random_device rd;
    std::mt19937 mt(rd());
    std::uniform_real_distribution<> RandX(0, Width);
    std::uniform_real_distribution<> RandY(0, -100);
    std::uniform_real_distribution<> RandZ(1,7);

    const int RainDrops = 2000;
    std::vector<RainDrop> Rain(RainDrops);
    for (auto & Drop : Rain) {
        Drop = RainDrop(RandX(mt),RandY(mt),RandZ(mt),0.1);
    }

    while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        window.clear();

        for (auto & Drop : Rain) {
            if (Drop.Fall()) {
                Drop.SetCoordX(RandX(mt));
                Drop.SetCoordY(RandY(mt));
            }
            Drop.Show(window);
        }
        window.display();
    }

    return 0;
}