Additionally, you can keep the long format by using the following method instead:
......
private long lastTime;
// Returns the duration of time since the last call to getDelta, in the supplied resolution (1000 for milliseconds, etc)
public long getDelta(long resolution)
{
long time = Sys.getTime();
long delta = ((time - lastTime * resolution)) / Sys.getTimerResolution();
lastTime = time;
return delta;
}
......
I prefer the first method, though (I like floating-point time stamps). It'd be simple to provide both, however (either synced together or independent).