osu/osu.Game.Rulesets.Osu/Difficulty/Skills/Speed.cs

69 lines
2.2 KiB
C#

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.
#nullable disable
using System;
using osu.Game.Rulesets.Difficulty.Preprocessing;
using osu.Game.Rulesets.Mods;
using osu.Game.Rulesets.Osu.Difficulty.Evaluators;
using osu.Game.Rulesets.Osu.Difficulty.Preprocessing;
using System.Collections.Generic;
using System.Linq;
namespace osu.Game.Rulesets.Osu.Difficulty.Skills
{
/// <summary>
/// Represents the skill required to press keys with regards to keeping up with the speed at which objects need to be hit.
/// </summary>
public class Speed : OsuStrainSkill
{
private double skillMultiplier => 1375;
private double strainDecayBase => 0.3;
private double currentStrain;
private double currentRhythm;
protected override int ReducedSectionCount => 5;
protected override double DifficultyMultiplier => 1.04;
private readonly List<double> objectStrains = new List<double>();
public Speed(Mod[] mods)
: base(mods)
{
}
private double strainDecay(double ms) => Math.Pow(strainDecayBase, ms / 1000);
protected override double CalculateInitialStrain(double time, DifficultyHitObject current) => (currentStrain * currentRhythm) * strainDecay(time - current.Previous(0).StartTime);
protected override double StrainValueAt(DifficultyHitObject current)
{
currentStrain *= strainDecay(((OsuDifficultyHitObject)current).StrainTime);
currentStrain += SpeedEvaluator.EvaluateDifficultyOf(current) * skillMultiplier;
currentRhythm = RhythmEvaluator.EvaluateDifficultyOf(current);
double totalStrain = currentStrain * currentRhythm;
objectStrains.Add(totalStrain);
return totalStrain;
}
public double RelevantNoteCount()
{
if (objectStrains.Count == 0)
return 0;
double maxStrain = objectStrains.Max();
if (maxStrain == 0)
return 0;
return objectStrains.Sum(strain => 1.0 / (1.0 + Math.Exp(-(strain / maxStrain * 12.0 - 6.0))));
}
}
}