Conway's Game of Life C++ SFML

#include <SFML/Graphics.hpp>
#include <windows.h>

const int width = 1920;
const int height = 1080;
const int xSize = 8;
const int ySize = 8;
const int cols = width / xSize;
const int rows = height / ySize;
int grid[cols][rows];
int newLife[cols][rows];

void Start()
{
    srand(time(NULL));
    for (int i = 0; i < cols; i++)
    {
        for (int j = 0; j < rows; j++)
        {
            grid[i][j] = rand() % 2;
        }
    }
}

void CalcNewStep()
{
    for (int g = 0; g < cols; g++)
    {
        for (int h = 0; h < rows; h++)
        {
            int neigh = 0;

            for (int i = -1; i < 2; i++)
            {
                for (int j = -1; j < 2; j++)
                {
                    if (grid[g+i][h+j] == 1)
                    {
                        neigh++;
                    }
                }
            }

            neigh = neigh - grid[g][h];

            if (grid[g][h] == 0)
            {
                if (neigh == 3)
                {
                    newLife[g][h] = 1;
                }
                else
                {
                    newLife[g][h] = 0;
                }
            }

            if (grid[g][h] == 1)
            {
                if (neigh == 2 || neigh == 3)
                {
                    newLife[g][h] = 1;
                }

                if (neigh > 3 || neigh < 2)
                {
                    newLife[g][h] = 0;
                }
            }
        }
    }
    for (int i = 0; i < cols; i++)
    {
        for (int j = 0; j < rows; j++)
        {
            grid[i][j] = newLife[i][j];
        }
    }
}

int main()
{
    sf::RenderWindow window(sf::VideoMode(width, height), "Conway's Game of Life");
    Start();

    for (int i = 0; i < cols; i++)
    {
        for (int j = 0; j < rows; j++)
        {
            sf::Vertex linesY[] =
            {
                sf::Vertex(sf::Vector2f(i* xSize, 0), sf::Color(105, 105, 105)),
                sf::Vertex(sf::Vector2f(i* xSize, height), sf::Color(105, 105, 105))
            };
            window.draw(linesY, 2, sf::Lines);
                sf::Vertex linesX[] =
            {
                sf::Vertex(sf::Vector2f(0, j* ySize), sf::Color(105, 105, 105)),
                sf::Vertex(sf::Vector2f(width, j* ySize), sf::Color(105, 105, 105))
            };
            window.draw(linesX, 2, sf::Lines);
        }
    }

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

        window.clear(sf::Color::Black);

        for (int i = 0; i < cols; i++)
            {
                for (int j = 0; j < rows; j++)
                {
                    if (grid[i][j] == 0)
                    {

                    }
                    else
                    {
                        sf::RectangleShape rect(sf::Vector2f(xSize, ySize));
                        rect.setFillColor(sf::Color::White);
                        rect.setPosition(i* xSize, j* ySize);
                        window.draw(rect);
                    }
                    sf::Vertex linesY[] =
                    {
                        sf::Vertex(sf::Vector2f(i* xSize, 0), sf::Color(105, 105, 105)),
                        sf::Vertex(sf::Vector2f(i* xSize, height), sf::Color(105, 105, 105))
                    };
                    window.draw(linesY, 2, sf::Lines);

                    sf::Vertex linesX[] =
                    {
                        sf::Vertex(sf::Vector2f(0, j* ySize), sf::Color(105, 105, 105)),
                        sf::Vertex(sf::Vector2f(width, j* ySize), sf::Color(105, 105, 105))
                    };
                    window.draw(linesX, 2, sf::Lines);
                }
            }


        window.display();
        CalcNewStep();
        Sleep(0);
    }
    return 0;
}