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我有一個問題,deltaTime我一直在使用。我的代碼如下:DeltaTime問題在程序啓動
public class Time {
public static float deltaTime = 0;
public static long frameCount = 0;
public static float fixedTime = 0;
public static float fixedDeltaTime = 0.1f;
public static float maxDeltaTime = 0.25f;
}
我MainThread.java現在在我的run()函數:
while (running) {
canvas = null;
try {
canvas = this.surfaceHolder.lockCanvas();
synchronized (surfaceHolder) {
float newTime = System.nanoTime()/1000000000.0f;
Time.deltaTime = frameTime = newTime - currentTime;
if(frameTime > Time.maxDeltaTime)
frameTime = Time.maxDeltaTime;
currentTime = newTime;
accumulator += frameTime;
while(accumulator > Time.fixedDeltaTime)
{
this.gamePanel.update(); // where the player and my enemy gets updated
accumulator -= Time.fixedDeltaTime;
}
this.gamePanel.render(canvas);
//Perform all non-physics-related updates here
++Time.frameCount;
framesSkipped = 0; // resetting the frames skipped
timeDiff = System.currentTimeMillis() - beginTime;
// calculate sleep time
sleepTime = (int)(FRAME_PERIOD - timeDiff);
if (sleepTime > 0) {
// if sleepTime > 0 we're OK
try {
Thread.sleep(sleepTime);
} catch (InterruptedException e) {}
}
while (sleepTime < 0 && framesSkipped < MAX_FRAME_SKIPS) {
// we need to catch up
this.gamePanel.update(); // update without rendering
sleepTime += FRAME_PERIOD; // add frame period to check if in next frame
framesSkipped++;
}
if (framesSkipped > 0) {
Log.d(TAG, "Skipped:" + framesSkipped);
}
// for statistics
framesSkippedPerStatCycle += framesSkipped;
// calling the routine to store the gathered statistics
storeStats();
}
} finally {
// in case of an exception the surface is not left in
// an inconsistent state
if (canvas != null) {
surfaceHolder.unlockCanvasAndPost(canvas);
}
} //end finally
}
}
在gamePanel.update( )我得到了玩家和我的敵人的更新通知。 我現在的問題是,在我的遊戲中的DeltaTime開始是都知道:高UND因此我的運動是非常快的,因爲我有我的敵人類的更新方法如下:
x += vX * Time.deltaTime; // velocity * deltaTime
y -= vY * Time.deltaTime;
//Log.d(TAG, "Time:"+Time.deltaTime+" x: "+x+" y: "+y);
vY -= gravity;
我在幹嘛它是正確的還是我的結構有問題? 感謝您的幫助。
你是對的。 currentTime初始設置爲0.您建議將其設置爲? System.nanoTime()呢?如果運動一開始就是0,那就不會那麼糟糕。感謝迄今 – puelo 2012-01-15 18:36:02
@ P.S.不需要使用毫秒來計算avgFps/currentFPS。當我測試deltaTime時,我不想影響fpsCount。但我想爲我的目的毫秒已經足夠了! – puelo 2012-01-15 18:39:00
@puelo - 我將它初始化爲System.nanoTime()。第一次迭代的運動爲零,因爲遊戲剛剛開始。這隻會發生一幀。 (順便說一下,我的猜測是,你的'beginTime'也有同樣的問題。) – 2012-01-15 18:43:47