Re: SVG API for canvas

Alex,

The overhead of SMIL (aka FROWN) will be greater than the performance
difference between javascript and C++. The math of calculating animation
keyframes is negligible in either language. I wrote up a testcase of 15,000
simultaneous animations at http://pr.gg/smil.html

On Chrome 37.0.2042.0 (canary) the javascript+rAF testcase is 10% faster
than SMIL. I profiled an instrumented build of Chrome and confirmed our
SMIL code is hot on this testcase. Safari 7 feels similar to Chrome. On
Firefox the javascript version certainly feels faster.



On Tue, Jun 10, 2014 at 6:07 AM, Alex Danilo <alex@abbra.com> wrote:

> >> On 6/9/14, 11:09 PM, Rik Cabanier wrote:
> >>> However, requestAnimationFrame should result in smoother animation than
> >>> SMIL.
> >>
> >> Why, exactly?
> >>
> >> -Boris
> >
> >In Blink (Chrome/Opera), svg animations (aka SMIL) are internally driven
> >by rAF too, so there should be no difference.
>
> Boris is right, sorry.
>
> JS driving the animation uses the JS engine to do the animation
> calculations
> instead of native code which can also take advantage of any browser
> internals
> it wants, like layers, etc.
>
> When JS execution speed matches C/C++ this _might_ be moot but the best
> asm.js results still show 50% slow-down (addmittedly on non-critical render
> times from what I've seen), however claiming rAF is equivalent to SMIL for
> performance is a bit of a stretch. To claim rAF is smoother than SMIL needs
> some hard data to support, and I'd bet that's lacking, please contradict
> this
> with some numbers if I've missed something.
>
> rAF can at best match but  not beat (or be smoother than) native SMIL if
> the stars are aligned nicely:-)
>
> Alex
>
>
>