显示FPS的方法

// A FPS counter.
// It calculates frames/second over each updateInterval,
// so the display does not keep changing wildly.

var updateInterval = 0.5;
private var lastInterval : double; // Last interval end time
private var frames = 0; // Frames over current interval
private var fps : float; // Current FPS

function Start() {
lastInterval = Time.realtimeSinceStartup;
frames = 0;
}

function OnGUI () {
// Display label with two fractional digits
GUILayout.Label("" + fps.ToString("f2"));
}

function Update() {
++frames;
var timeNow = Time.realtimeSinceStartup;
if( timeNow > lastInterval + updateInterval )
{
fps = frames / (timeNow - lastInterval);
frames = 0;
lastInterval = timeNow;
}
}