Re: gEDA-user: PCB GTK version...

[Jakub Piotr CÅapa <jpc@xxxxxxxxxxxxx>]

Bill Wilson wrote:
> On Wed, 27 Jul 2005 15:41:58 +0200
> Jakub Piotr C__apa <jpc@xxxxxxxxxxxxx> wrote:
>
> > Ales Hvezda wrote:
> >
> > > [snip]
> > >
> > > Interesting thread, but nobody answered my first question:
> > >
> > > What specifically is it about gtk+ 2.[4|6] that is so much slower than
> > > say gtk+ 1.x? 
> >
> > That's a good question (bot wrong list probably)... :)
>
> I think he's asking for slower specifics wrt gschem and the gtk pcb
> and not in general.

I didn't really notice big differences but I haven't really used both on 
something older than Athlon 1,33 (I rarely use a Celeron 333 but I got 
used to making myself a cup of tea while waiting for any program to 
launch on it ;-)

> > > I haven't notice critical amounts of slowdown in gschem
> > > or gtkPCB on my P2-400/256M.  Certainly pango and friends do impact text
> > > rendering performance and I have noticed longer startup times because
> > > of the larger number of dependencies
> >
> > Blender also has many dependencies and starts almost instantly.
>
> On Ales' P2-400?  Blender takes several seconds to start on my k6-2 450.

Ok, I have a PentiumM 1,8 but I find it much faster than any GTK+2 app 
so thats not a linker issue.

> I've a test program that shows Gtk pango text draws using gdk_draw_layout() can
> be 20-40 times slower than xlib text draws using gdk_draw_string(), but pango
> text is used in Gtk PCB only for pinout numbers and I'm not sure if it is
> used on gschem schematics.  The pcb and gschem drawing areas use
> gdk draw functions which are mostly short simple single function wrappers around
> the xlib equivalent calls so raw drawing speed should be good.

The pango text is (probably sub-pixel) anti-aliased so it must take 
longer. I know that not everybody loves text anti-aliasing but I really 
like this feature (if done right --- I can't call ClearType a pleasant 
experience).

Btw. IMHO the anti-aliased drawings would be a really cool feature to 
have. I find them really more readable and pleasant to look at and cairo 
is a pretty cool drawing(/printing/graphicing ;)) library.

> [...]
>
> While Gtk can be slow for apps that heavily use Pango or large treeviews,
> it really depends on the app and general Gtk complaints don't really help
> with respect to any possible real issues with Gtk PCB or gschem.

I'm afraid it slows much more things but I kind of lost some interest in 
it since I bought a new laptop (and that's probably the reason the GTK+2 
developers also don't consider it critical ;).

> And we still don't know the original posters hardware or what his
> specific complaint was, and yet it sure lit some fires :)

It's mostly my fault. Sorry...

--
Regards,
Jakub Piotr CÅapa