Re: [gtkmm] Re: How to do call a function once every 'frame'? And some documentation feedback.

[Dirk Gerrits <dirk gerrits homeip net>]

Hi Bassoukos,

Bassoukos Tassos wrote:

> On Sat, 2002-11-09 at 17:20, Dirk Gerrits wrote:
>
>
> >But if I understand correctly, with Glib::signal_timeout() the whole
> >DoFrame function becomes unnecessary:
> >
> >Glib::signal_timeout().connect(SigC::slot(&DoComputation), ms_per_tick);
> >
> >That's just plain cool! :) Thanks.
> >
> >Dirk
>
>
> Hello Dirk,
> unfortunately that is not the case! Gtkmm (and most non-Hard-RT
> operating systems) only guarantee that the time interval is *at least*
> as much as what you specified, never less (e.g. your slot will never 
> be called earlier, but possibly later).

I do think think this gaurantee should be in the reference docs.

> That means that you will need to both calculate how much time has 
> passed since the last call and to calculate the remaining time after 
> your computation has finished[1].
>
> HTH,
> Tassos
> [1] consider: your computation takes 10 ms, and then you wait for
>     another 20: sum total 33 ms or 30 frames per second, much less than
>     20ms or 50 frames per second.

Hmm, I see. Well than I guess I can recycle some of that DoFrame pseudo 
code. ;) Too bad the one liner doesn't work, but I do understand why 
this would be necessary.

Thanks again,

Dirk