除了我的代码以外，其他原因会加速计时吗？

Question

进入我的游戏几秒钟，一切都加快了。我的代码找不到任何问题，但是肯定有一个问题。我想知道我的显卡是否有可能加速发展。任何建议将不胜感激，谢谢！

#include <SFML/Graphics.hpp>
#include <iostream>
#include <chrono>
#include <ctime>    
#include "PongGame.h"

int main()
{

    PongGame game(10);
    sf::RenderWindow window(sf::VideoMode(1500, 900), "SFML works!");

    float UPDATE_INTERVAL = 900000000.0f;
    float lag = 0.0f;

    typedef std::chrono::high_resolution_clock Time;
    typedef std::chrono::milliseconds ms;
    typedef std::chrono::duration<float> fsec;
    auto prevTime = Time::now();

    while (window.isOpen())
    {
        auto currTime = Time::now();
        fsec fs = currTime - prevTime;
        ms d = std::chrono::duration_cast<ms>(fs);
        lag += d.count();
        //std::cout << "lag1: " << lag << "\n";
        while (lag > UPDATE_INTERVAL) {
            std::cout << "loop";
            sf::Event currEvent;
            while (window.pollEvent(currEvent))
            {
                if (currEvent.type == sf::Event::Closed) { window.close(); }
            }
            game.PollKeys();
            game.Update(1.0f);
            game.Render(1.0f, &window);
            //lag -= UPDATE_INTERVAL;
            lag = 0;
            std::cout << "lag2: " << lag << "\n";
        }
    }

    return 0;
}

@ Howard Hinnant

我现在以毫秒为单位比较所有内容。我现在已经逐步完成了很多代码，但我不明白为什么它会如此加速。这是新代码：

#include <SFML/Graphics.hpp>
#include <iostream>
#include <chrono>
#include <ctime>    
#include "PongGame.h"

int main()
{
    typedef std::chrono::high_resolution_clock hiResTime;
    typedef std::chrono::milliseconds ms;
    typedef std::chrono::high_resolution_clock::time_point time_point;

    PongGame game(10);
    sf::RenderWindow window(sf::VideoMode(1500, 900), "SFML works!");
    time_point prevTime = hiResTime::now();
    time_point currTime = hiResTime::now();
    const ms UPDATE_INTERVAL(99999999);
    ms lag(0);

    while (window.isOpen())
    {
        prevTime = currTime;
        time_point currTime = hiResTime::now();
        ms currInterval = std::chrono::duration_cast<std::chrono::milliseconds>(currTime - prevTime);
        lag += currInterval;
        if (lag > UPDATE_INTERVAL) {
            //std::cout << "loop";
            sf::Event currEvent;

            if ((window.pollEvent(currEvent)) && (currEvent.type == sf::Event::Closed)) { window.close(); }
            game.PollKeys();
            game.Update(1.0f);
            game.Render(1.0f, &window);

            //lag -= UPDATE_INTERVAL;
            lag = ms(0);
        }
    }
    return 0;
}

Answer 1

在旧版本的代码中，您忘记更新prevTime。在当前版本中，您仍不执行此操作，因为currTime中的prevTime = currTime;是直接在main()中定义的变量，但由于time_point currTime = hiResTime::now();定义了具有相同名称的新变量（允许使用，因此永远不会更新）因为它在嵌套块中）而不是更新先前定义的块。因此，第一个currTime始终包含游戏的开始时间。