RFR: 8372203: Piecewise linear easing function

[Andy Goryachev]

On Fri, 21 Nov 2025 21:46:07 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> Implementation of the [linear](https://www.w3.org/TR/css-easing-2/#the-linear-easing-function) easing function, which is now widely supported by all browsers, but still missing in JavaFX.
>> 
>> It allows developers to approximate arbitrary easing functions with linear segments:
>> 
>> 
>> linear(
>>     /* Start to 1st bounce */
>>     0, 0.063, 0.25, 0.563, 1 36.4%,
>>     /* 1st to 2nd bounce */
>>     0.812, 0.75, 0.813, 1 72.7%,
>>     /* 2nd to 3rd bounce */
>>     0.953, 0.938, 0.953, 1 90.9%,
>>     /* 3rd bounce to end */
>>     0.984, 1 100% 100%
>>   )
>> 
>> 
>> <img src="https://github.com/user-attachments/assets/73aac0d4-0185-47c5-8791-bdb247eb69c8" width="400"/>
>
> modules/javafx.graphics/src/main/java/com/sun/scenario/animation/LinearInterpolator.java line 198:
> 
>> 196: 
>> 197:         // Linearly interpolate (or extrapolate) along the segment (ax, ay) -> (bx, by).
>> 198:         if (ax == bx) {
> 
> FP alert: is it possible for `ax != bx` yet the result of division on L203 to produce an infinity?

jshell> 1 / 9e-310
$25 ==> Infinity

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PR Review Comment: https://git.openjdk.org/jfx/pull/1977#discussion_r2551083513