osu/osu.Game.Rulesets.Taiko/Difficulty/TaikoPerformanceCalculator.cs

113 lines
4.4 KiB
C#

// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
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.Rulesets.Taiko.Objects;
namespace osu.Game.Rulesets.Taiko.Difficulty
{
public class TaikoPerformanceCalculator : PerformanceCalculator
{
private readonly int beatmapMaxCombo;
private Mod[] mods;
private int countGreat;
private int countGood;
private int countMeh;
private int countMiss;
public TaikoPerformanceCalculator(Ruleset ruleset, IBeatmap beatmap, Score score)
: base(ruleset, beatmap, score)
{
beatmapMaxCombo = beatmap.HitObjects.Count(h => h is Hit);
}
public override double Calculate(Dictionary<string, double> categoryDifficulty = null)
{
mods = Score.Mods;
countGreat = Convert.ToInt32(Score.Statistics[HitResult.Great]);
countGood = Convert.ToInt32(Score.Statistics[HitResult.Good]);
countMeh = Convert.ToInt32(Score.Statistics[HitResult.Meh]);
countMiss = Convert.ToInt32(Score.Statistics[HitResult.Miss]);
// Don't count scores made with supposedly unranked mods
if (mods.Any(m => !m.Ranked))
return 0;
// Custom multipliers for NoFail and SpunOut.
double multiplier = 1.1; // This is being adjusted to keep the final pp value scaled around what it used to be when changing things
if (mods.Any(m => m is ModNoFail))
multiplier *= 0.90;
if (mods.Any(m => m is ModHidden))
multiplier *= 1.10;
double strainValue = computeStrainValue();
double accuracyValue = computeAccuracyValue();
double totalValue =
Math.Pow(
Math.Pow(strainValue, 1.1) +
Math.Pow(accuracyValue, 1.1), 1.0 / 1.1
) * multiplier;
if (categoryDifficulty != null)
{
categoryDifficulty["Strain"] = strainValue;
categoryDifficulty["Accuracy"] = accuracyValue;
}
return totalValue;
}
private double computeStrainValue()
{
double strainValue = Math.Pow(5.0 * Math.Max(1.0, Attributes["Strain"] / 0.0075) - 4.0, 2.0) / 100000.0;
// Longer maps are worth more
double lengthBonus = 1 + 0.1f * Math.Min(1.0, totalHits / 1500.0);
strainValue *= lengthBonus;
// Penalize misses exponentially. This mainly fixes tag4 maps and the likes until a per-hitobject solution is available
strainValue *= Math.Pow(0.985, countMiss);
// Combo scaling
if (beatmapMaxCombo > 0)
strainValue *= Math.Min(Math.Pow(Score.MaxCombo, 0.5) / Math.Pow(beatmapMaxCombo, 0.5), 1.0);
if (mods.Any(m => m is ModHidden))
strainValue *= 1.025;
if (mods.Any(m => m is ModFlashlight))
// Apply length bonus again if flashlight is on simply because it becomes a lot harder on longer maps.
strainValue *= 1.05 * lengthBonus;
// Scale the speed value with accuracy _slightly_
return strainValue * Score.Accuracy;
}
private double computeAccuracyValue()
{
// Todo: This int cast is temporary to achieve 1:1 results with osu!stable, and should be remoevd in the future
double hitWindowGreat = (int)(Beatmap.HitObjects.First().HitWindows.Great / 2) / TimeRate;
if (hitWindowGreat <= 0)
return 0;
// Lots of arbitrary values from testing.
// Considering to use derivation from perfect accuracy in a probabilistic manner - assume normal distribution
double accValue = Math.Pow(150.0 / hitWindowGreat, 1.1) * Math.Pow(Score.Accuracy, 15) * 22.0;
// Bonus for many hitcircles - it's harder to keep good accuracy up for longer
return accValue * Math.Min(1.15, Math.Pow(totalHits / 1500.0, 0.3));
}
private int totalHits => countGreat + countGood + countMeh + countMiss;
}
}