Help with smoothing game loop

Newbie & Debugging Questions
#1

Hello peeps,
First post here.

I have been working on a game loop and can’t seem to get the frames/game to run smoothly
I was wondering if anyone could have a look at the code and see if they know why its laggy every so often.

http://pastebin.com/HPEa9dfV

Thanks in advanced!

#2

It looks fine. In fact, that whole sleeping code looks like mine :wink:

Maybe it’s your computer?

#3

80% was made from you :stuck_out_tongue:
Hm, I just cant help but see it jump every so often.
Im OSX based? could it be the shitty graphics performance of OSX?

#4

Yup, I blame OS X.

#5

:(, despite the hate, +1 internets to you!
Thanks for the help + the code :wink:

#6

Try to turn the ‘wait loop’ into:

while(System.nanoTime() < nextFrame) {
   Thread.yield();
}

If that smoothens the framerate, then the problem lies in the ‘accuracy’ of Thread.sleep(1).

If that doesn’t solve it, try this:

while(System.nanoTime() < nextFrame) {
   ; // do nothing
}

If that smoothens the framerate, then the problem lies in the ‘accuracy’ of Thread.yield().

If that doesn’t solve it, you’re screwed. Probably some background-process is grabbing CPU cycles, or your OS is swapping.

#7

If the problem is with the ‘accuracy’ of Thread.sleep(1), try using that sleeping trick everyone talks about:


new Thread() {
    {
        setDaemon(true);
        start();
    }
    
    public void run() {
        while(true) {
            try { Thread.sleep(Long.MAX_VALUE); } catch(Exception exc) {}
        }
    }
};
#8

I was just seeking advice about my graphics driver loop code. I use the nanosecond sleep call (but not sure if this would help your case):


if (wait > 0)
{
    long mill = wait / NS_PER_MS;
    long nano = wait - (mill * NS_PER_MS);
    Thread.currentThread().sleep(mill, (int)nano);
}
#9

Thread.sleep(millis, nanos) simply calls Thread.sleep(millis).

That method shouldn’t have existed. :cranky:

#10

Thanks for the help guys!
I have been playing around with the sleep call, but still seem to get the same results
Ive tested it on 2 Macs I have (MBA and iMac), I obviously get better frames on the iMac compared to the MBA
FYI, it looks like the BufferImage just stops for a split second then resume’s, it doesnt really ‘skip’ a frame, it just pauses (kind of annoying)

Is there a more accurate way of calculating the sleep time?

I thought if i tried a simpler loop it may help? (that might have been stupid of me)
And it didn’t :stuck_out_tongue:


unprocessed += (now - lastTime)/nanosPerTick;
while(unprocessed >= 1){
	ticks++;
	update();
	unprocessed = 0;
	shouldRender = true;
}
	if(shouldRender){
		frames++;
		render();
}
			
try {
	Thread.sleep(1);
} catch (Exception e) {
	e.printStackTrace();
}

Like you guys mentioned it seems it has more to do with the thread then the loop/render - update

Thanks again!