[Sugar-devel] SVG performance

[Walter Bender]

On Tue, Dec 9, 2008 at 9:52 AM, Tomeu Vizoso <tomeu at sugarlabs.org> wrote:
> On Tue, Dec 9, 2008 at 3:34 PM,  <pgf at laptop.org> wrote:
>> walter wrote:
>>  > And in the case of TA, I currently render about 30 svg files in the
>>  > initialization phase, hence the long delay. I'll look into how I can
>>  > background some of this.
>>
>> there's only so much cpu.  how will that help?
>
> Placeholders could appear instantly, and those would be replaced by
> the rendered blocks when each of those are ready.
>
> Or we could block only on the ones that are visible at startup, then
> render the rest on the background.

This is what I have in mind... but I need to do some intervention in
the overall flow of the TA start up.

>
>> i'd still like to know how fast it would be to render the equivalent
>> bitmap.
>>
>> clearly SVG is the wave of the future, but current h/w is the
>> wave of the past.  if pre-rendering our icons in predictably
>> needed sizes (at build-time, not run-time) would help a lot, then
>> it seems like we should do that.
>
> I think the problem is that they depend on the screen size and
> language, but we could render them at first boot and keep a cache on
> disk. So first run would be slow, but provided we give appropriate
> feedback, might not be so bad.
>
> As many people have pointed before, there are loads of techniques that
> were used when computers were much slower and more value was delivered
> to the user. We cannot use all of those techniques for various
> reasons, but many still hold valid.
>
> Regards,
>
> Tomeu
>
>> paul
>>
>>  >
>>  > -walter
>>  >
>>  > On Tue, Dec 9, 2008 at 9:11 AM, Tomeu Vizoso <tomeu at sugarlabs.org> wrote:
>>  > > On Tue, Dec 9, 2008 at 3:04 PM,  <pgf at laptop.org> wrote:
>>  > >> bernie wrote:
>>  > >>  > Jim Gettys wrote:
>>  > >>  > > IIRC, librsvg is it.
>>  > >>  > >
>>  > >>  > > A bit more profiling to get through the tangled web of dependencies is
>>  > >>  > > probably in order.
>>  > >>  >
>>  > >>  > To exclude the noise coming from  Python and GDK, I tried timing again
>>  > >>  > with the command-line tool rsvg:
>>  > >>  >
>>  > >>  >   for i in *.svg; do echo $i; time rsvg $i $i.png; done
>>  > >>  >
>>  > >>  > This way I could not find any problematic svg file within the
>>  > >>  > turtleart repository.  The slowest ones render in <0.1 seconds.
>>  > >>
>>  > >> i'm not sure i'd agree that "<0.1 seconds" isn't problematic.  how
>>  > >> fast would the equivalent bitmap render?
>>  > >
>>  > > In order to not give a perception of slugginesh, all UI operations
>>  > > should take less than 0.2s.
>>  > >
>>  > > If one icon takes 0.05s, we can render 4 of them before starting to look slow.
>>  > >
>>  > > So we need to make those values much lower, or stop rendering icons
>>  > > during UI operations.
>>  > >
>>  > > Regards,
>>  > >
>>  > > Tomeu
>>  > > _______________________________________________
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>>  > > Sugar-devel at lists.sugarlabs.org
>>  > > http://lists.sugarlabs.org/listinfo/sugar-devel
>>  > >
>>  >
>>  >
>>  >
>>  > --
>>  > Walter Bender
>>  > Sugar Labs
>>  > http://www.sugarlabs.org
>>
>> =---------------------
>>  paul fox, pgf at laptop.org
>>  give one laptop, get one laptop --- http://www.laptop.com/xo
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Regarding the difference between SVG and GIF rendering on the XO, it
is ~ 4x slower: 20+ seconds vs 5+ seconds for initialization.

-walter


-- 
Walter Bender
Sugar Labs
http://www.sugarlabs.org