On Sat, 27 Nov 2004, James Wright wrote:
> My understanding is that flat panels do not "scan" a screen as a CRT does,
> so there is no vertcial blank period to perform a page flip. They do have a
> refresh rate of usually around 60Hz, but his is simply how aften the pixels
> are able to switch states, or how often the display is refreshed from the
> panels backbuffer. In a DGA mode if you try waiting for a vblank with a flat
> panel, then the page flip is performed immediately, instead of waiting for
> anything. The panels own circuits decide when to change the display anyway,
> so anything you try to do yourself is moot. If I am incorrect, then I
> apologise...
>
That's sortof the correct idea for when using the panel's VGA
interface. For the VGA interface, the panel is not necessarily
refreshing at the rate coming through the VGA connector. For DVI,
the panel is refreshing at the rate coming through the DVI connector,
but this doesn't necessarily correspond to the timings programmed
in the VGA registers. At least on the hardware I've worked on,
the VGA timing merely correspond to the input to the flat panel
scaler in the graphics chip, not the output going to the panel.
Mark.
>
>
> On Sat, 27 Nov 2004 13:37:01 -0500
> Michel Dänzer <[EMAIL PROTECTED]> wrote:
>
> > On Sat, 2004-11-27 at 16:40 +0000, James Wright wrote:
> > > About a year ago I was using DGA for my games graphics library. I
> > > was told by various people that using DGA was not the way to go. At
> > > first I thought this was nonsense, as you can't get vsync using the
> > > more standard XPutImage method (and get tearing). However, all changed
> > > when I bought a laptop with TFT screen. Problem is, there is no vsync
> > > on the new LCD/TFT monitors!
> >
> > There is in my experience, at least if you use the panel's native mode.
> >
> >
> > --
> > Earthling Michel Dänzer | Debian (powerpc), X and DRI developer
> > Libre software enthusiast | http://svcs.affero.net/rm.php?r=daenzer
> >
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