On Sun, 21 Dec 2025 16:10:45 GMT, Marius Hanl <[email protected]> wrote:
>> Ah yes, you are right, I skipped over the `+=` operation; indeed it also
>> needs snapping. It is simply the reality that even when values are already
>> snapped, adding two snapped values together can still introduce a rounding
>> error that must be resnapped.
>
> Should we snap the (here intermediate) value of `getSpacing()` as well? We
> could do that once before the whole for loop, and use the value. But I'm not
> sure if that even makes a difference?
Well, it is already snapped in its own way:
private final double getSpacing() {
return spacing == null ? 0.0 : snapSpacing(spacing.get());
}
And even when it is snapped, once there's potential for decimal component
(i.e., introduced by 1.25 scaling) in its value, then there's a risk of these
floating point rounding errors when adding it to anything else.
So I don't think it makes any difference to what is done with the spacing
value. I think what matters is that the final value of x is rounded off, which
is really the point of snapPosition.
This snapPosition on x call could be done at the end, outside of the for loop
either, I imagine, also. As long as a final value looks like 123.62, and not
123.62000000000001.
-------------
PR Review Comment: https://git.openjdk.org/jfx/pull/2016#discussion_r2637973119
