Fix "spins per minute" shows up early (fix #31173)

[Rudicito]

Fix #31173

Make isSpinnableTime public in SpinnerRotationTracker and use it to set Tracking in OsuModSpunOut.

Tracking was previously set to true, causing the "spins per minute" to appear immediately when the spinner appeared.

Before:

before.mp4

After:

after.mp4

Sorry for the low framerate of the videos.
I hope the PR is okay.

[smoogipoo]

Makes logical sense to me.

[bdach]

It doesn't to me.

The alpha of the spm stuff is steered by TimeStarted on the judgement result:

osu/osu.Game.Rulesets.Osu/Skinning/Argon/ArgonSpinner.cs

Lines 124 to 125 in 84ab5a5

	if (drawableSpinner.Result?.TimeStarted is double startTime)
	spmContainer.Alpha = (float)Math.Clamp((Clock.CurrentTime - startTime) / drawableSpinner.HitObject.TimeFadeIn, 0, 1);

which is documented as:

osu/osu.Game.Rulesets.Osu/Judgements/OsuSpinnerJudgementResult.cs

Lines 29 to 32 in 84ab5a5

	/// <summary>
	/// Time instant at which the spin was started (the first user input which caused an increase in spin).
	/// </summary>
	public double? TimeStarted;

and set by:

osu/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableSpinner.cs

Lines 328 to 329 in 84ab5a5

	if (Result.TimeStarted == null && RotationTracker.Tracking)
	Result.TimeStarted = Time.Current;

If Tracking can be true before the spinner actually becomes spinnable, then isn't that an issue? What stops this issue from happening outside of the Spun Out mod context?

[bdach]

I guess the answer to my question is this:

osu/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableSpinner.cs

Lines 279 to 286 in 84ab5a5

	if (HandleUserInput)
	{
	bool isValidSpinningTime = Time.Current >= HitObject.StartTime && Time.Current <= HitObject.EndTime;
	RotationTracker.Tracking = !Result.HasResult
	&& correctButtonPressed()
	&& isValidSpinningTime;
	}

but like I dunno. This feels like a very shallow fix.

At least if this is to remain this way the "valid spinning time" checks should be consistent and they're even not. There's like a difference in the equality operators used in both.