Re: [hatari-devel] Blitter emulation corner case

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 17/05/2017 à 19:00, Nicolas Pomarède a écrit :
> I will have a closer look to the example in the blitter doc, the generic 
> bitmap copy routine computes NFSR/FXSR, it could be interesting to see 
> which case they take in the end.
Looking at the example in blitter.pdf doc by Atari, we can see there's a 
special case when the number of pixels to copy uses only a 1 word width 
in destination.
 - If source is only 1 word, then copy is performed with FXSR=0 and NFSR=0
 - If source pixels are on 2 words (and dest is one 1 single word), 
then it means pixels need to be shifted and in that case only FXSR is set.

(the example doesn't handle if src/dest region overlap, so Xinc/Yinc 
will be >0)