pisces, produceFillAlphas

[Jim Graham]

Perhaps optimization flags with the native compiler?  Also, was it 
called a similar number of times on both?

Ideally we'd just be using copyArea for the scrolling, but at one point 
we disabled the scrolling optimizations on retina MBP because they 
didn't work with a scale factor and I don't think we reenabled them yet. 
  That would kill scrolling performance on mobile as a result of having 
to rerender the scene on each scroll regardless of how long 
produceAlphas takes...

			...jim

On 10/15/15 4:27 AM, Johan Vos wrote:
> After spending lots of time optimizing JavaFX on iOS, I am now at the point
> where scrolling is 10 times faster on iOS than on Android.
> The scrolling in the iOS version of the Gluon JavaOne mobile schedule
> builder is pretty good imho. On Android, it is much slower. I profiled and
> compared both, and it turns out that on Android, we spend lots of time in
> the native implementation of NativePiscesRasterizer.produceFillAlphas
> (implemented in native-prism/NativePiscesRasterizer.c)
>
> On average, calling this native function on an iPhone 6 takes 40,000ns
> whereas on a Nexus 6, this takes about 800,000ns.
>
> If anyone has a suggestion on how to improve or avoid this, I'm all ears.
>
> Thanks,
>
> - Johan
>