[REBOL] Re: Rebol on Amithlon?
From: holger:rebol at: 24-Nov-2001 12:12
On Sat, Nov 24, 2001 at 06:53:04PM +0000, Don Cox wrote:
> I generally run on 8-bit 1024x768 screens, and that would be what I used
> for View. The scrolling was much slower than on other programs, such as
> the Voyager web browser, running on the same screen mode.
Probably because the scripts you used did not use hardware
scrolling, but rather rerendered all data during every refresh.
You can scroll by only changing the offset of a face, then
setting face/changes to 'offset and calling 'show. This
procedure significantly improves performance, by an order of
magnitude.
There are other tricks that can improve performance,
such as using transparency only where necessary, and using
non-transparent background colors everywhere else. You
won't notice the difference on PCs, but you will on slow
machines like the Amiga. Unfortunately most scripts out
there are written and tested on PCs and therefore not
optimized because the developers would never notice the
effect of such optimizations on their machines.
> As Voyager is loading and assembling 24-bit JPEGs, it must have similar
> tasks to perform.
>
> Surely you don't have to do C2P conversion for a CGFX display?
No, but you still have to quantize 24-bit to 8-bit in real-time.
Plus, for scripts that do not use hardware scrolling the whole
screen has to be refreshed every time. For large screens
such as 1024x768 that obviously takes some time.
> Well, no doubt it will be usable with faster processors, but I feel
> there is something wrong somewhere. A program ought to run at a good
> speed on a 68060 with a graphics card.
View is quite usable on an 060 with graphics board if you
use properly written scripts that make use of hardware
scrolling and do not refresh faces more than necessary.
The Conference applet of Express e.g. performs quite
well on an Amiga, including scrolling.
> PS tried it again, but this time I couldn't get it to open on its own
> screen. No tooltypes, no ASL screen requester, no preferences menu. Just
> a very ugly window on the workbench in what looked like 8 colours, with
> no dithering or anti-aliasing. There was a big bright green square at
> the bottom left, for some reason. It looked like it was just using
> RGBYMC white and black. Next to the GlowIcons in the WB windows, this
> looks bad.
Sounds like you either have bad screen options in user.r or you
are using a patch that redirects REBOL to a different screen mode
than requested. The View docs have some information on how to
set your user.r to use custom screens.
> I really want Rebol to succeed, but it will have to present better than
> this.
Unfortunately, given the complete lack of a commercial Amiga
market these days, there is not much of a chance that we will
be able to concentrate a lot on platform-specific
improvements for the Amiga any time soon, so REBOL's success
is unlikely to be determined by the performance of the Amiga
port. Similarly for the BeOS port, given the situation BeOS
is in.
--
Holger Kruse
[holger--rebol--com]
