Re: X.org on Amiga, 16 color mode

[David Brownlee <abs%absd.org@localhost>]

On Sun, 3 Mar 2024 at 18:53, Jukka Andberg <jukka.andberg%welho.com@localhost> wrote:
>
> Frank Wille wrote Sat, 02 Mar 2024 12:24:38 +0100:
> > Jukka Andberg wrote:
> >
> > > Working solution seems to be creating the shadowfb with 8bpp and
> > > depth 4, and then handling conversion from 8bpp pixels to 4
> > > bitplanes in the shadow update function.
> > >
> > > For the conversion it needs a new shadow update function, which is
> > > pretty similar to existing shadowUpdateAfb4, just reading 8-bit
> > > input pixels instead of 4-bit pixels.
> > >
> > > Patch attached. Any thoughts?
> >
> > I think this could work. Nice work!
> >
> > Maybe it makes sense to optimize at least the inner loop of the
> > shadowUpdateAfb4x8() routine into assembler, once it works.
>
> Maybe something to check, yes.

It's possible that if it is good to go this could just make the cut
for NetBSD-10.0 (though releng may well throw a brickbat my way for
suggesting that :)

> Performance-wise there seems to be also something else in the new
> server that makes it slower than Xamiga, even with the existing
> black/white solution a simple thing like moving the mouse pointer
> feels slower.

IIUC the new code ends up dealing with 8 bpp internally in places
where the old could use 1 bpp. (Though always thought that using a
sprite for the X cursor would have been a cute feature on the Amiga
:-p)

David