Re: [hatari-devel] error reading video counter on TT since commit 5316b4081e9d3

[Thomas Huth <th.huth@xxxxxxxxx>]

Am Sat, 23 Jul 2022 11:26:55 +0200
schrieb Nicolas Pomarède <npomarede@xxxxxxxxxxxx>:

> Le 23/07/2022 à 08:09, Thomas Huth a écrit :
> 
> > Instead of reverting, I'd suggest that we just add a special "else" case
> > here to fake a video counter update in TT and Falcon mode, e.g.:
> > 
> > 	if (!Config_IsMachineTT() && !Config_IsMachineFalcon())
> > 	{
> > 		Video_EndHBL();
> > 	}
> > 	else
> > 	{
> > 		/* Fake video counter update in TT and Falcon mode...
> > 		 * should be replaced once we have more precise video
> > 		 * emulation there: */
> > 		pVideoRaster = ((pVideoRaster - STRam + SCREENBYTES_MIDDLE)
> > 		                & 0xffffff) + STRam;
> > 	}
> > 
> > SCREENBYTES_MIDDLE should maybe be adjusted depending on the video mode....
> > Does that sound acceptable?  
> 
> Hi
> 
> I'm not sure this would be fail proof enough ; in the case of 
> hextracker, it compares with video addr at start of screen, but some 
> other program could wait for line 1 or end of screen for example. Also 
> you should not return the above value unless DE has really started (ie 
> not during top border) or it will mess with other cases/

I already jumped the gun and committed the quick fix to get Hextracker
working again (since it's really a trivial change). Agreed that this could
use more precision, especially also for the enhanced resolutions of the TT,
or course.

> I will have a look if you don't plan doing it youself ? (I think I can 
> patch it today)

If you've got some spare time and motivation for implementing a better
solution, that would be very welcome!

 Thomas