Allow setting osu!mania scroll speed to single decimal precision

[peppy]

Probably fine to allow this?

Addresses #30663.

[frenzibyte]

This change makes it somewhat awkward for players to downgrade from a release that has this change. The following exception is thrown:

[runtime] 2024-11-24 01:41:41 [error]: System.FormatException: The input string '22.0' was not in a correct format.
[runtime] 2024-11-24 01:41:41 [error]: at System.Number.ThrowFormatException[TChar](ReadOnlySpan`1 value)
[runtime] 2024-11-24 01:41:41 [error]: at System.String.System.IConvertible.ToInt32(IFormatProvider provider)
[runtime] 2024-11-24 01:41:41 [error]: at System.Convert.ChangeType(Object value, Type conversionType, IFormatProvider provider)
[runtime] 2024-11-24 01:41:41 [error]: at osu.Framework.Bindables.Bindable`1.Parse(Object input, IFormatProvider provider)

Can be replicated by running osu! on this branch and change the scroll speed to any value, decimal or non-decimal, then run the game again on master.

I can see two options toward this:

• Add special handling in config decoding for when a decimal value is read while the expected type is integer, by truncating said decimal value.
• Create another setting temporarily ScrollSpeedDecimal for the decimal type and, optionally, after a while migrate the setting back to its original name.

While the first option adds perhaps too much leniency to config decoding, I can't really imagine it going wrong myself.

[frenzibyte]

Might be a blocker.

[peppy]

But that's the same as any realm change, no? Are you worried about live users or developers? If the latter, it can be fixed as a separate effort if deemed required?

[frenzibyte]

I'm worried about live users running a new release that turned out to be broken for them and they have to revert back. All of them will have to manually pop up their config file and remove the decimal part to be able to run an old release.

We're quite fast on rolling out hotfixes so if you think it's fine for this to be breaking then I'm fine.

[peppy]

Only if they change the scroll speed then install an old version, right? It's the same as if we roll out an update with a realm change, equal levels of breakage. In general we don't/can't support rollback to older releases in our current development state.

[smoogipoo]

Would've suggested something like Shift+F3/F4 to change by 0.1 increments, but I'm not sure how hard that will be to implement so will get this in as is for now.