RFR: 8217472: Add attenuation for PointLight [v5]

[Nir Lisker]

On Wed, 13 May 2020 23:50:37 GMT, Kevin Rushforth <kcr at openjdk.org> wrote:

>>> We should make sure that we aren't seeing any significant performance drop when rendering spheres (at a couple
>>> different tessellation levels) or boxes.
>> 
>> I missed this. Do you mean that the test should create a mesh of a sphere instead of a flat surface?
>
> I would say in addition to rather than instead of, since both are useful.
> 
> What might help is to add the sphere test plus the pathological test I put together into your test program so we can
> select between them. And then get a few of us to run that updated program and post results.

I've added sphere with 10, 64 (default) and 200 divisions. Note that this number is approximate because the sphere mesh
corrects the division number with `newDivisions = ((oldDivisions + 3) / 4) * 4`.
[attenTest.zip](https://github.com/openjdk/jfx/files/4855989/attenTest.zip)

Using AMD RX 470 4GB on Win 10, all 3 spheres averaged 120 fps both before and after the patch. (It takes a couple of
measurements to hit the consistent fps, so I discarded them.)

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PR: https://git.openjdk.java.net/jfx/pull/43