-----Original Message----- From: Engelen, J.B.C. (Johan) Sent: maandag 16 juni 2008 17:45 To: 'bulia byak' Cc: Anhalter42@...173...; inkscape-devel@lists.sourceforge.net Subject: RE: [Inkscape-devel] Startup slowdown caused by nr_arena_updates?
-----Original Message----- From: bulia byak [mailto:buliabyak@...400...] Sent: maandag 16 juni 2008 17:14 To: Engelen, J.B.C. (Johan) Cc: Anhalter42@...173...; inkscape-devel@lists.sourceforge.net Subject: Re: [Inkscape-devel] Startup slowdown caused by nr_arena_updates?
On Mon, Jun 16, 2008 at 10:27 AM, <J.B.C.Engelen@...1578...> wrote:
I changed bbox calculation to use the 2geom path instead of
NArtBpath.
I'll do some tests whether this is much slower. Right now I am thinking this is very bad news for my project: it might
mean that path
transformation (operator*) is significantly slower in the
2geom lib
than NR lib...
No need to despair - there was simply no motivation so far
to speed up
2geom. Now this motivation is aplenty. I also noticed the slowdowns during work; part of them (during transformations) I traced down to path data writing and reported to Jasper who was looking into it, but part is also
undoubtedly blameable
on 2geom. So let's make this a call to arms for all 2geom devels to make 0.47 not a bit slower - and ideally faster - than 0.46.
Thank you for your positive note Bulia!
I was a bit unfair... the "slow" function used to use the rough bbox at first (defined by the handles of the path), instead of the exact bounding box. So I changed that in the code now. Still, operator*(Geom::Path, Geom::Matrix) is a "slow" function, and a lot of time is spent there. So we could try to focus optimizing attempts there.
(I like -pg and gprof for profiling!)
The above was false, Inkscape 0.46 *does* use the exact bounding box in that method, so I changed that back. I have refactored the bbox calculation for transformed paths and it is a lot faster now. To conclude I think the huge speed improvement comes from: 1 - no longer generating transformed path, but taking separate points and transforming those 2 - use optimized bbox calculation for straight line segments and cubic segments, instead of the default root finding algorithm.
Now, Inkscape is super fast starting up. Might be worth doing a measurement against Inkscape 0.46, to see how it compares.
Cheers, Johan
(and now I absolutely love -pg and gprof for profiling!)