Re: GNOME 2.3.x DirectFB support

[Mike Hearn <mike theoretic com>]

On Sun, 18 May 2003 18:55:36 +0200, Sir Ali Akcaagac scribed thus:
> startup-notification, libwnck, libbonoboui, ..., and a few more needs
> deeper changes because a bunch of parts are simply to tied to X11. 

Not so much tied to X11, more that they need some kind of IPC system. If I
recall correctly, DirectFB were developing an in-kernel IPC engine called
Fusion, which was supposed to replace that part of X11 but I don't know
how far along it is. Rewriting those libraries to use that would need to
wait until DirectFB is feature-competitive with X.

> Please respect that I don't want to start a discussion about why I like
> to have GNOME run on directfb and what you think that I think may be
> wrong with XFree and why not use xdirectfb and so on but my personal
> interests with directfb are simple and I want to give you a few personal
> reasons.

Having GNOME run on DirectFB would be a fine thing indeed. Not sure I'd
personally use it, but then DFB isn't quite as mature yet as XFree is,
perhaps given time it might work better.

> a) Memory consumption. I think that XFree eats to much memory,

Remember that XFree stores pixmaps internally, so that's effectively
memory "stolen" from other apps. If you're using top, it'll also show the
framebuffer memory region I think.

> b) Loading times of XFree86

I haven't used DirectFB so I can't really compare, but with the free nv
drivers X loads in about 2 seconds for me.

> c) Speed and more direct hardware access,

XFree is pretty fast at most things, but perceived speed is affected by a
lot of things. I suspect you see the flashing of damaged areas repainting
as "slowness", which is indeed what it feels like. That's not an inherant
property of X or Xfree though, just need a good backing store
implementation.

> d) nearly 130 mb of XFree86 compared to 200-300 kb of directfb libs.

I think that's mostly fonts. Anyway, remember that XFree includes stuff
like a terminal program, window manager, and lots of other tools that
simply counting the DFB libs does not.

> e) to make GNOME to use as many GDK functions as possible instead of
>    directly calling X11 calls.
> f) to interest the developer during development to think about using
>    GDK calls in favor of direct X11 calls whenever possible.


That would be good if possible, yes.

thanks -mike