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



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