On Mon, 24 Dec 2001, Andreas Reich wrote:
> Christoph Egger ([EMAIL PROTECTED]) wrote:
> > On Sun, 23 Dec 2001, Andreas Reich wrote:
>
> >> but it *would* be possible to simulate double-buffering like this:
> >> 1.) SetMode() to 800x600, virtual 1600x600
> >> 2.) Draw on the left 800x600 part of the virtual screen
> >> 3.) SetOrigin() to 0,0
> >> 4.) Draw on the right 800x600 part of the virtual screen
> >> 5.) SetOrigin() to 800,0
> >> 6.) GOTO 2.)
> >> Right?
> > No. The right way is:
> > 1.) ggiSetMode() to 800x600, virtual 1600x600
> > 2.) Draw on the virtual screen
> > 3.) ggiSetOrigin() lets you scroll without redrawing things.
> > 4.) GOTO 2.)
>
> OK, true for scrolling. But for general double-buffering (animations
> etc.) you have to do it the way I described.
No. Use ggi{Set|Get}{Read|Write|Display}Frame() instead.
See man ggiSetDisplayFrame for more information.
> >> That's OK. I'm working on a windowing library for our own embedded
> >> systems, and we'll probably never use a PPC in there.
> > Cool. Which device do you use exactly?
>
> We're going to use standard i386 hardware, our own PCI cards for I/O
> and multiple graphic cards. When you heard "embedded", you probably
> thought of things like Linux-on-a-Chip, but here embedded just means
> that the user doesn't actually notice there is a PC running inside the
> device. (OK, s/he *does* notice because of the boot screens, but it
> doesn't matter to him/her.)
I see.
> See http://www.grandma.de/ to see something similar to what we're
> working on.
Cool. BTW: A note for non-german speakers: There's a link to english-sites
on the startup-page.
> > Note: You don't need to install DirectFB. You only need the binary
> > drivers.
>
> I had a look at DirectFB, but I guess it won't be useful for me
> because it relies on the Linux FB drivers.
Exactly. That's the goal of that project and therefore not so flexible
than GGI.
> There is a (non-Vesa) framebuffer driver for the Banshee chipset in my
> test machine, but it's broken: The text is messed up if I boot into
> resolutions higher than 640x480. That's why I use vesafb.
Well, that's definitely a bug in the driver and not in GGI.
> Enough for today 8-)
Good night.
CU,
Christoph Egger
E-Mail: [EMAIL PROTECTED]
