RFR: 8220484: JFXPanel renders a slanted image with a hidpi monitor scale of 125% or 175% [v2]

[Kevin Rushforth]

On Tue, 30 Jun 2020 18:21:52 GMT, Oliver Schmidtmer <github.com+10960818+Schmidor at openjdk.org> wrote:

>> In 2D, we normally use sun.java2d.pipe.Region.clipRound as it also checks for -ve/+ve max INTEGER but I guess that is
>> internal class to FX so it's ok to use Math.round.  Approval pending test creation.
>
> While both might work, as long as there is no mixed usage of round and ceil, Math.ceil seems to be better.
> 
> I'm not sure if the timed waiting for the resizes is the best way for ensuring that the buffer is resized to the new
> bounds, so I'm open for suggestions. To me at least it seems to create a reproducible sheared output after the second
> resize in the test case and not anymore after changing the calculations to Math.ceil.

This fix might be a candidate for JavaFX 15, so I recommend to _not_ merge the master branch.

If we don't spot anything of concern during the review, then we might ask you to retarget your PR to the `jfx15` branch.

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PR: https://git.openjdk.java.net/jfx/pull/246