osu/osu.Game.Rulesets.Mania/Difficulty/ManiaPerformanceCalculator.cs

129 lines
4.8 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.
using System;
using System.Collections.Generic;
using System.Linq;
using osu.Game.Beatmaps;
using osu.Game.Rulesets.Difficulty;
using osu.Game.Rulesets.Mods;
using osu.Game.Rulesets.Scoring;
using osu.Game.Scoring;
namespace osu.Game.Rulesets.Mania.Difficulty
{
public class ManiaPerformanceCalculator : PerformanceCalculator
{
protected new ManiaDifficultyAttributes Attributes => (ManiaDifficultyAttributes)base.Attributes;
private Mod[] mods;
// Score after being scaled by non-difficulty-increasing mods
private double scaledScore;
private int countPerfect;
private int countGreat;
private int countGood;
private int countOk;
private int countMeh;
private int countMiss;
public ManiaPerformanceCalculator(Ruleset ruleset, WorkingBeatmap beatmap, ScoreInfo score)
: base(ruleset, beatmap, score)
{
}
public override double Calculate(Dictionary<string, double> categoryDifficulty = null)
{
mods = Score.Mods;
scaledScore = Score.TotalScore;
countPerfect = Score.Statistics[HitResult.Perfect];
countGreat = Score.Statistics[HitResult.Great];
countGood = Score.Statistics[HitResult.Good];
countOk = Score.Statistics[HitResult.Ok];
countMeh = Score.Statistics[HitResult.Meh];
countMiss = Score.Statistics[HitResult.Miss];
if (mods.Any(m => !m.Ranked))
return 0;
IEnumerable<Mod> scoreIncreaseMods = Ruleset.GetModsFor(ModType.DifficultyIncrease);
double scoreMultiplier = 1.0;
foreach (var m in mods.Where(m => !scoreIncreaseMods.Contains(m)))
scoreMultiplier *= m.ScoreMultiplier;
// Scale score up, so it's comparable to other keymods
scaledScore *= 1.0 / scoreMultiplier;
// Arbitrary initial value for scaling pp in order to standardize distributions across game modes.
// The specific number has no intrinsic meaning and can be adjusted as needed.
double multiplier = 0.8;
if (mods.Any(m => m is ModNoFail))
multiplier *= 0.9;
if (mods.Any(m => m is ModEasy))
multiplier *= 0.5;
double strainValue = computeStrainValue();
double accValue = computeAccuracyValue(strainValue);
double totalValue =
Math.Pow(
Math.Pow(strainValue, 1.1) +
Math.Pow(accValue, 1.1), 1.0 / 1.1
) * multiplier;
if (categoryDifficulty != null)
{
categoryDifficulty["Strain"] = strainValue;
categoryDifficulty["Accuracy"] = accValue;
}
return totalValue;
}
private double computeStrainValue()
{
// Obtain strain difficulty
double strainValue = Math.Pow(5 * Math.Max(1, Attributes.StarRating / 0.2) - 4.0, 2.2) / 135.0;
// Longer maps are worth more
strainValue *= 1.0 + 0.1 * Math.Min(1.0, totalHits / 1500.0);
if (scaledScore <= 500000)
strainValue = 0;
else if (scaledScore <= 600000)
strainValue *= (scaledScore - 500000) / 100000 * 0.3;
else if (scaledScore <= 700000)
strainValue *= 0.3 + (scaledScore - 600000) / 100000 * 0.25;
else if (scaledScore <= 800000)
strainValue *= 0.55 + (scaledScore - 700000) / 100000 * 0.20;
else if (scaledScore <= 900000)
strainValue *= 0.75 + (scaledScore - 800000) / 100000 * 0.15;
else
strainValue *= 0.90 + (scaledScore - 900000) / 100000 * 0.1;
return strainValue;
}
private double computeAccuracyValue(double strainValue)
{
if (Attributes.GreatHitWindow <= 0)
return 0;
// Lots of arbitrary values from testing.
// Considering to use derivation from perfect accuracy in a probabilistic manner - assume normal distribution
double accuracyValue = Math.Max(0.0, 0.2 - (Attributes.GreatHitWindow - 34) * 0.006667)
* strainValue
* Math.Pow(Math.Max(0.0, scaledScore - 960000) / 40000, 1.1);
// Bonus for many hitcircles - it's harder to keep good accuracy up for longer
// accuracyValue *= Math.Min(1.15, Math.Pow(totalHits / 1500.0, 0.3));
return accuracyValue;
}
private double totalHits => countPerfect + countOk + countGreat + countGood + countMeh + countMiss;
}
}