[hatari-devel] Re: [Emutos-devel] blitter

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On 05/08/2017 07:57 PM, Christian Zietz wrote:
> "Markus Fröschle" schrieb:
>
>> Feel free to pull the fork at https://github.com/mfro0/emutos for
>> testing and address any issues to me.
>
> Tested on my 1040STFm with added Blitter. I noticed that some of the
> icons on the desktop are not correctly redrawn after I open and then
> close the desktop's preferences dialog. The edge of this dialog goes
> right through the icons in question. See
> <https://ocean.czietz.de/index.php/s/SXMOS3jsuI1yGge>
>
> Happens on the STE, as well.

On 05/08/2017 09:56 PM, Christian Zietz wrote:
> Christian Zietz schrieb:
> > Like you, I also wasn't able to reproduce this with Hatari. But I can
> > reproduce the incorrectly drawn icons with Steem SSE 3.9.1. Maybe
> > Blitter emulation in Hatari is not 100% accurate?

CCing hatari-devel.  I assume Nicolas will be interested about
any emulation issues.

Which Hatari version you used?


> I used part of the debugging code in do_blit() to dump the Blitter
> configuration prior to the call to blitter_do_blt(blt).

In the Hatari debugger you can use:
	info blitter

To check current blitter settings.


	- Eero

> Here's a case where an icon is drawn correctly:
>
> X COUNT 2
> Y COUNT 32
> X S INC -2
> Y S INC -2
> X D INC -2
> Y D INC -78
> ENDMASK 0xffff-ffff-0007
> S_ADDR  0x00026c7e
> D_ADDR  0x003fac74
> HOP 2, OP 7
> NFSR=1,FXSR=1,SKEW=0
>
> ... while this is a case where the icon is *not* drawn correctly like
> shown in my previous photo:
>
> X COUNT 1
> Y COUNT 32
> X S INC -2
> Y S INC -4
> X D INC -2
> Y D INC -80
> ENDMASK 0xffff-ffff-0007
> S_ADDR  0x00026c7e
> D_ADDR  0x003fac72
> HOP 2, OP 7
> NFSR=1,FXSR=1,SKEW=0
>
> As you can see the difference is that the X count is only 1. Probably
> something special happens (in the real Blitter and in Steem) when only
> one word per line is copied, that is not properly accounted for in your
> code.
>
> Regards
> Christian