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  From: becka@rz.uni-duesseldorf.de
  To  : ggi-develop@eskimo.com
  Date: Wed, 5 May 1999 01:18:36 +0200 (MEST)

Re: Dynamic linking problem?

> > FBDev does not work with my vesafb(ywrap) or rivafb kgicon (TNT),

> Probably because the hardcoded frames. Run 'fbset -i' and check the
> ypanstep entry. If it's zero you can only have one frame on those
> drivers. Otherwise I'm not sure what might be the problem.

Or to put it in other words: Check the number of frames you got for
the mode.

> > but it works with matroxfb (Mystique).

> > BTW: Do you know why there is flickering using FBDev or DGA
> > although I use doublebuffering (or panning in FBDev), AGP problem?

> Are you sure that you are really using double buffering? The current
> CVS version of Clanlib are not using it:

Hmm - he should see artifacts on the X target, if he wouldn't be doing it
right - or ?

I have that very same problem with the cube3d demo when running on the
Permedia KGI driver. It get's lots of flicker, if I scale the cube to just
the right size.

The problem is, that I do _not_ wait on CRT retrace, as there is no 
mechanism to do it on fbdev (is there ? If yes, please tell me, so we 
can hack the ggimisc extension to use it).

This results in me flipping frames in the middle of a screen, which can
cause anything from a strange striped effect like a VCR in search mode
(happens when the card instantly changes pages as instructed) to black
stripes wandering around the screen that happen, if the card only cares
for the offset at the frame start (switches within the screen will
let the program _think_ the buffer it now draws on is in BG, though it is
still displayed).

So anyone knows, how to query/wait on CRT ray position on XFDGA and/or 
fbdev ? We should at least add it to the extra KGI ioctls ...
the Permedia _can_ do it, and I even know how :-).

CU, ANdy

-- 
= Andreas Beck                    |  Email :  <andreas.beck@ggi-project.org> =

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