[hatari-devel] Mahabharata demo problem ?

[Eero Tamminen]

Hi,

On torstai 13 tammikuu 2011, David Savinkoff wrote:
> >    I don't know what happen, but when I launch the Mahabharata demo
> >    with the latest hatari, all my linux applications close, my linux
> >    cession close too. I have to sign me to return to my gnome
> >    environment. (of course, hatari is closed too)
> >    
> >    Do you encounter something similar ?
> >    
> >    It seems to do this only with this demo (maybe something related to
> >    Eero's patch about strange screen's size) ?
>
> On my system this demo temporarily makes an extremely wide
> window on several occasions (in windowed mode). This wide
> window is of unbounded size,

Not unbounded sizes.  During the demo, 5120x200 and 5120x240
sized resolutions are requested several times.

I think there could be some corner-case that Hatari Videl code isn't
emulating.   Maybe the real HW clips large resolutions and like ST/STE
does something "unexpected" when being requested funny resolution
changes.


With my aspect correction code the height is doubled while it remains less
than half of width, but is still smaller than width and the zoom max height
setting.

If one would have unbounded max height setting, it would result in
resolution of 5120x3200 which at 32-bits is 62.5MB of RAM for that
surface.  With the default max height of ~600, it should take "only"
~11MB of RAM.

That's still rather large video surface, but my integrated Intel HD graphics
handles it fine.  I think even my old Matrox G550 (~10 years old) handled it
fine.


> possibly causing a buffer overflow on your system. Ok on mine.

I added to Hatari a rather large patch which among other things limits
resolution request dimensions to desktop size before aspect correction
(potentially) zooms it in one of the directions.

On quick look Videl code should be clipping its conversions if host screen
size is smaller than requested resolution, so that kind of limiting
shouldn't crash Hatari.

Laurent, could you test whether this fixes your X server crash?


	- Eero

PS. The aspect correction max size will now by default be that size too.
If you have saved Hatari configuration, you can in SDL GUI increase
the max aspect correction zoom size to your desktop size.
(Unless you want Hatari window to keep smaller)