RFR: 8211294: ScrollPane content is blurry with 125% scaling

[Frederic Thevenet]

On Fri, 18 Dec 2020 16:54:46 GMT, Kevin Rushforth <kcr at openjdk.org> wrote:

>> So that leaves two follow-on bugs then:
>> 1. Rendering a cached node doesn't match rendering it directly even when the transform is unchanged.
>> 2. TextFlow: methods copied from Region have not picked up subsequent changes in those methods
>
> I filed the following follow-on bugs:
> 1. [JDK-8258694](https://bugs.openjdk.java.net/browse/JDK-8258694) : Rendering cached nodes with sub-pixel translation is blurry
> 2. [JDK-8258697](https://bugs.openjdk.java.net/browse/JDK-8258697) : TextFlow: methods copied from Region have diverged

I've added a test that verifies that the inset values for a scrollpane in a scene are snapped to whole pixels, given the actual screen scale.
The test passes without this fix for screen scale of 100% or 200% but fails at 125%, 150% and 175%
With this fix, it passes at all screen scale.

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PR: https://git.openjdk.java.net/jfx/pull/308