Java 每x毫秒更新一个对象

我有个问题。要制作视频游戏，我必须实现一个名为update（）的函数

参数lastCallTime是我们最后一次调用update

它必须做到以下几点：

计算自上次调用更新以来经过的时间

如果经过的时间比ifUpdate=true多20[ms]

并重置每个对象的上次更新时间

线程将以以下方式调用此方法：

@Override
public void run(){
    long lastCallTime;
    int k = 0;

    lastCallTime = System.currentTimeMillis();
    while(true){
        //Do something
        boolean ifUpdate = update(lastCallTime);          
    }
}

---

不久前，我写了一些类似的东西。 update方法将以FPS速率调用（示例中为24）。因此，需要计算更新方法所消耗的时间（变量

timeDiff

）。还将检查进程睡眠时间是否大于或小于所指示的时间（变量

overSleepTime

），此时间将在下一个周期中被加/减

我希望它能帮助你

long timeDiff, sleepTime;
long afterTime, beforeTime;
long overSleepTime = 0L;

int fps = 24; // the desire FPS
long period = 1000000000L / fps;

while(true) {
  beforeTime = System.nanoTime();

  // your game logic
  update();

  afterTime = System.nanoTime();

  // timeDiff is time needed by the update process
  timeDiff = afterTime - beforeTime;
  sleepTime = (period - timeDiff) - overSleepTime;

  if(sleepTime > 0) {
    try {
      Thread.sleep(sleepTime / 1000000L); // sleeptTime is in nano secs and sleep expects millis
    } catch(InterruptedException e) {}

    // checks if the thread has slept more than desired
    overSleepTime = (System.nanoTime() - afterTime) - sleepTime;

  } else {
    // negative sleeptTime means that the system can't be update at the desired rate
    overSleepTime = 0L;
  }
}

---

}

lastUpdated=System.currentTimeMillis（）

instrad of

=0

@darijan:事实上，我想你应该希望

lastUpdated=currentTime

。你应该看看观察者的模式我不明白为什么lastUpdated=0；因为你想让它在最后一次更新1）这是秋千吗？2） 为了更快地获得更好的帮助，请发布一个。3） 不要阻止EDT（事件调度线程）-发生这种情况时，GUI将“冻结”。不要调用

Thread.sleep（n）

为重复任务执行Swing

计时器，或为长时间运行的任务执行
SwingWorker
。有关更多详细信息，请参阅。4） 你的问题是什么？
long timeDiff, sleepTime;
long afterTime, beforeTime;
long overSleepTime = 0L;

int fps = 24; // the desire FPS
long period = 1000000000L / fps;

while(true) {
  beforeTime = System.nanoTime();

  // your game logic
  update();

  afterTime = System.nanoTime();

  // timeDiff is time needed by the update process
  timeDiff = afterTime - beforeTime;
  sleepTime = (period - timeDiff) - overSleepTime;

  if(sleepTime > 0) {
    try {
      Thread.sleep(sleepTime / 1000000L); // sleeptTime is in nano secs and sleep expects millis
    } catch(InterruptedException e) {}

    // checks if the thread has slept more than desired
    overSleepTime = (System.nanoTime() - afterTime) - sleepTime;

  } else {
    // negative sleeptTime means that the system can't be update at the desired rate
    overSleepTime = 0L;
  }
}