java - 为什么这个游戏循环滞后？

Question

我对 Java 完全陌生，并尝试编写自己的小游戏循环

package com.luap555.main;

import java.awt.Graphics;
import java.awt.image.BufferStrategy;

import javax.swing.Timer;

public class Game implements Runnable{

private Window window;
public int width, height;
public String title;

private boolean running = false;
private Thread thread;

private BufferStrategy bs;
private Graphics g;

private int fps = 60;
private long lastTime;
private long now;
private long delta;
private long timer;
private long ticks;
private boolean initialized = false;

public Game(String title, int width, int height) {
    this.title = title;
    this.width = width;
    this.height = height;

}

private void init() {
    window = new Window(title, width, height);
    Assets.init();
    System.out.println("Initializing finished");
    initialized = true;
}

private int x = 0;

private void tick() {
        x += 1;

}

private void render() {
    bs = window.getCanvas().getBufferStrategy();
    if(bs == null) {
        window.getCanvas().createBufferStrategy(3);
        return;
    }
    g = bs.getDrawGraphics();

    g.clearRect(0, 0, width, height);

    g.drawImage(Assets.unten, 0 + x, 0, 700, 350, null);

    bs.show();
    g.dispose();
}

private void runtick() {
        lastTime = System.currentTimeMillis();

        tick();

        now = System.currentTimeMillis();
        delta += now - lastTime;

        try {
            Thread.sleep((delta + 1000) / fps);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        delta -= now - lastTime;
}

private void runrender() {
    render();
}

@Override
public void run() {
    init();

    if(initialized) {
        while(running) {
            runtick();
            runrender();
        }
    }

    stop();

}

public synchronized void start() {
    if(running)
        return;
    running = true;
    thread = new Thread(this);
    thread.start();

}

public synchronized void stop() {
    if(!running)
        return;
    running = false;
    try {
        thread.join();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

}

在我的主要方法中，我调用 game.start() 方法。但每当我运行这段代码时，图片的移动就相当滞后。我的移动相当流畅，但每隔一秒左右就会出现一些滞后。我认为问题出在“runtick()”方法中。有谁知道为什么会发生这种情况？我希望你们中的一些人可以帮助我；D

Answer 1

您将根据游戏逻辑所需的时间来增加游戏的 sleep 时间。您想要做的是根据游戏逻辑所需的时间来减少 sleep 。

您还需要将渲染时间纳入您的计算中(在很多游戏中，这很快就会变得比游戏逻辑时间长)。尝试这样的事情:

long delta, end, start = System.currentTimeMillis();
while (running) {
    runtick();
    runrender();

    end = System.currentTimeMillis();
    delta = (end - start);
    Thread.sleep((1000 / fps) - delta);
    start = end;
}

如果您发现delta变得大于tick间隔(1000/fps)，那么您应该记录一些警告，并为了缓解这种情况，您可以在每个渲染tick中运行多个游戏逻辑tick，以允许游戏逻辑 catch 动画。