Re: [hatari-devel] New blitter code for xcount=1 nfsr=1

[Thomas Huth <th.huth@xxxxxxxxx>]

Am Thu, 10 Sep 2020 17:44:23 +0200
schrieb Nicolas Pomarède <npomarede@xxxxxxxxxxxx>:

> Hi
> 
> some times ago we had several examples of wrong blitter emulation
> when xcount=1 and nfsr=1 at the same time.
> 
> Various tests showed some different result depending on "source x 
> increment" values and other parameters maybe.
> 
> Thanks to the work by Ijor who did a Verilog implementation of the 
> blitter, based on some reverse engineering as well as on the
> blitter's schematics that Christian Zietz found some years ago, I was
> able to fix this behaviour under Hatari and get all the cases to work
> under Hatari using the small test program that Christian wrote at
> this time (see attached BLIT.ZIP for reference)

Great job! It's really cool to see Hatari getting more and more
accurate!

Any chance you could add that test from BLIT.ZIP to the "make test"
regression test suite?

> I tried some games / demos that make use of the blitter and didn't
> see any regression so far (Lethal Xcess, We Were by Oxygene, rgbbeast
> by agression, sea of colors by dhs, ...)
> 
> Given the number of changes, it's possible some cases were forgotten. 
> Please test your favorite STE games/demos that use the blitter and 
> report any problem.

I just tried "Pacemaker" from Paradox, and as far as I can see, all
looks fine.

 Thomas