Re: [GD-Consoles] Generic MP3 Player for Playstation 2

[Arn <ar...@bl...>]

Alistair Milne wrote:
> [..]
> > Rachid El Guerrab
> > [..]
> > It's mostly some jittering.. and my guess is that it mostly happens in my
> > collision processing (lots of floating point computations). And I
> > have that
> > behavior too when I'm far away from the center of my sector (Big floating
> > numbers).
> 
> When you do a floating point multiply on the PS2, the lowest order bit of
> the mantissa effectively becomes random.  You cannot get around this.  This
> is why you get the jitter.  You need to scale things so that the lowest
> order bit makes the smallest possible difference to the outcome.

I also had jitter problems and tracked them down to my camera
matricies.  The sin/cos functions I was using for one of the camera
modes wasn't giving accurate enough results.  I replaced with the
sin/cos with the algorithm described in the VU manuals and all of my
jitter problems went away.


Arn