在 Java 游戏中计算 FPS
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Calculate FPS in Java Game
提问by SirTrashyton
Yesterday I wrote a Thread addressing how my game loop ran (in java) and how it works.
昨天我写了一个线程来解决我的游戏循环如何运行（在 Java 中）以及它是如何工作的。
My game loop works completely, and I know why, but now I just wan't to know how to calculate FPS (Frames Per Second) and print it out every second.
我的游戏循环完全正常，我知道为什么，但现在我只是不知道如何计算 FPS（每秒帧数）并每秒打印出来。
I got a response yesterday about this, but he/she explained it in words and I couldn't understand it.
我昨天收到了关于这个的回复，但他/她用语言解释了，我无法理解。
If anyone could help me (with a code example? :D) that would be great.
如果有人可以帮助我（使用代码示例？:D）那就太好了。
Here is my game loop:
这是我的游戏循环：
while (running) {
start = System.nanoTime();
update();
draw();
drawToScreen();
elapsed = System.nanoTime() - start;
wait = targetTime - elapsed / 1000000;
if (wait < 0) {
wait = 5;
}
try {
Thread.sleep(wait);
} catch (Exception e) {
Game.logger.log("ERROR! Printing Stacktrace...");
e.printStackTrace();
}
}
ALSO:
还：
In my JFrame when ever I call setName(string) it never works/updates on the Frame - Link me to a thread?
在我的 JFrame 中，当我调用 setName(string) 它永远不会在框架上工作/更新 - 将我链接到一个线程？
回答by Trojan
You can combine a simple counter and Timer.scheduleAtFixedRatefor this.
您可以为此组合一个简单的计数器和Timer.scheduleAtFixedRate。
Disclaimer: I don't know if this is the best method; it's just easy.
免责声明：我不知道这是否是最好的方法；这很容易。
int totalFrameCount = 0;
TimerTask updateFPS = new TimerTask() {
public void run() {
// display current totalFrameCount - previous,
// OR
// display current totalFrameCount, then set
totalFrameCount = 0;
}
}
Timer t = new Timer();
t.scheduleAtFixedRate(updateFPS, 1000, 1000);
while (running) {
// your code
totalFrameCount++;
}
回答by Justin
The easiest way to do this is to keep a variable whatTheLastTimeWasstored and doing this where you want to check your frame rate:
最简单的方法是保存一个变量whatTheLastTimeWas并在您想要检查帧速率的地方执行此操作：
double fps = 1000000.0 / (lastTime - (lastTime = System.nanoTime())); //This way, lastTime is assigned and used at the same time.
Alternatively, you can make a FPS counter like so:
或者，您可以像这样制作 FPS 计数器：
class FPSCounter extends Thread{
private long lastTime;
private double fps; //could be int or long for integer values
public void run(){
while (true){//lazy me, add a condition for an finishable thread
lastTime = System.nanoTime();
try{
Thread.sleep(1000); // longer than one frame
}
catch (InterruptedException e){
}
fps = 1000000000.0 / (System.nanoTime() - lastTime); //one second(nano) divided by amount of time it takes for one frame to finish
lastTime = System.nanoTime();
}
}
public double fps(){
return fps;
}
}
Then in your game, have an instance of FPSCounterand call nameOfInstance.interrupt();when one frame is finished.
然后在你的游戏中，当一帧完成时有一个FPSCounter和调用的实例nameOfInstance.interrupt();。
