Timing distribution graph shows slider head hits in an unintuitive way on classic scores

[bdach]

Type

Game behaviour

Bug description

Originally reported on discord. Opening as issue because I'm not sure what to do with this one.

The slider head circle is judged either as a full circle (with classic mod off), or as a large slider tick (with classic mod on):

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

Lines 83 to 93 in 551c243

	protected override HitResult ResultFor(double timeOffset)
	{
	Debug.Assert(HitObject != null);
	if (HitObject.JudgeAsNormalHitCircle)
	return base.ResultFor(timeOffset);
	// If not judged as a normal hitcircle, judge as a slider tick instead. This is the classic osu!stable scoring.
	var result = base.ResultFor(timeOffset);
	return result.IsHit() ? HitResult.LargeTickHit : HitResult.LargeTickMiss;
	}

Notably, when classic mod is on, the head circle is judged as a large slider tick, but contrary to normal slider ticks, it still has non-empty hit windows due to inheriting from HitCircle : OsuHitObject:

osu/osu.Game.Rulesets.Osu/Objects/SliderHeadCircle.cs

Line 9 in 551c243

public class SliderHeadCircle : HitCircle

osu/osu.Game.Rulesets.Osu/Objects/OsuHitObject.cs

Line 156 in 551c243

protected override HitWindows CreateHitWindows() => new OsuHitWindows();

The hit event distribution graph discards hit events for objects with empty hit windows:

osu/osu.Game/Screens/Ranking/Statistics/HitEventTimingDistributionGraph.cs

Line 62 in 551c243

this.hitEvents = hitEvents.Where(e => !(e.HitObject.HitWindows is HitWindows.EmptyHitWindows) && e.Result.IsHit()).ToList();

However, with classic active, slider heads are objects that are judged as ticks but have non-empty hit windows, leading them to be included on the stacked bar graph (in the topmost position on each bar). What compounds the confusion is the fact that they will always be painted on the graph using blue:

osu/osu.Game/Graphics/OsuColour.cs

Lines 92 to 95 in 551c243

	case HitResult.SmallTickHit:
	case HitResult.LargeTickHit:
	case HitResult.Great:
	return Blue;

With classic off, this just isn't an issue because the slider heads are judged as standard circles.

Screenshots or videos

Version

current master

Logs

n/a

[peppy]

Is the fix here as simple as returning empty windows when classic mod is enabled (probably via a flag set somewhere on the OsuHitObject, or applied by the mod – HitWindows is publicly settable)?

[bdach]

Is the fix here as simple as returning empty windows when classic mod is enabled (probably via a flag set somewhere on the OsuHitObject, or applied by the mod – HitWindows is publicly settable)?

I'm 99% sure it is not. Doing this would essentially mean that with classic mod active the slider head would need to be hit with zero offset to be considered as hit. As in precise to the millisecond.

This isn't an issue for normal slider ticks as they are generally not timed objects and judgements on them are set via their parent objects using slider tracking state.