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Timer & FPS

Posted: Sat Sep 03, 2005 5:20 pm
by gershon
why is my delta-time constantly changing?

u32 time = timer->getTime()
float dt = (float)( time - time2 )
time2 = time

Posted: Sun Sep 04, 2005 8:06 am
by Guest
Because that is what Delta time does. If it was constant all the time there would be no need for it :)

It measures how long the last frame took and returns the result - which can always fluctuate.

However large fluctuations are a sign of something bad in your code, but you didn't post your average results so I don't know how bad they are!?

Posted: Sun Sep 04, 2005 8:35 pm
by gershon
donno what i did exacty, movment was jercky but now it working... :)
at ~200 fps i get values of 1-44.
i use it as:
v = a * (dt/1000)

Posted: Mon Sep 05, 2005 6:24 am
by CZestmyr
I don't know what is your problem, but physical formulas are clear:
v = a * dt
s = v * dt
with relatively small dt, which is your case, you can use
v = a * t
s = v * t