RFR: 8332895: Support interpolation for backgrounds and borders [v2]

[Michael Strauß]

On Thu, 1 Aug 2024 23:21:12 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> Michael Strauß has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   fixed a bug
>
> modules/javafx.graphics/src/main/java/javafx/scene/layout/BackgroundPosition.java line 266:
> 
>> 264:                            Side verticalSide, double verticalPosition, boolean verticalAsPercentage) {
>> 265:         return this.horizontalSide == horizontalSide
>> 266:             && this.horizontalPosition == horizontalPosition
> 
> so here `==` seems to be ok since we are comparing enums and primitive values, but...
> should we account for floating point errors that might appear during interpolation?
> i.e.
> 
> isClose(this.horizontalPosition, horizontalPosition) &&
> 
> 
> where
> 
> private static boolean isClose(double a, double b) {
>  return Math.abs(a - b) < EPSILON; // 0.00001 or something like that should be ok for screen coordinates
> }

I don't think that this is necessary. It would only save an allocation in a exceedingly rare case where the interpolation factor was microscopically different from either 0 or 1. This shouldn't happen in practice.

> modules/javafx.graphics/src/main/java/javafx/scene/layout/Border.java line 331:
> 
>> 329: 
>> 330:         for (int i = 0, max = strokes.size(); i < max; i++) {
>> 331:             final BorderStroke stroke = strokes.get(i);
> 
> just curious: do we really need `final` keyword for local variables after java8?

I don't use it, but I didn't change the existing code here.

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PR Review Comment: https://git.openjdk.org/jfx/pull/1522#discussion_r1701071650
PR Review Comment: https://git.openjdk.org/jfx/pull/1522#discussion_r1701072138