diff --git a/osu.Game.Rulesets.Taiko.Tests/TaikoDifficultyCalculatorTest.cs b/osu.Game.Rulesets.Taiko.Tests/TaikoDifficultyCalculatorTest.cs index e00f3da0b7..16130c2c3d 100644 --- a/osu.Game.Rulesets.Taiko.Tests/TaikoDifficultyCalculatorTest.cs +++ b/osu.Game.Rulesets.Taiko.Tests/TaikoDifficultyCalculatorTest.cs @@ -18,7 +18,7 @@ namespace osu.Game.Rulesets.Taiko.Tests public void Test(double expected, string name) => base.Test(expected, name); - protected override LegacyDifficultyCalculator CreateDifficultyCalculator(WorkingBeatmap beatmap) => new TaikoLegacyDifficultyCalculator(new TaikoRuleset(), beatmap); + protected override LegacyDifficultyCalculator CreateDifficultyCalculator(WorkingBeatmap beatmap) => new TaikoDifficultyCalculator(new TaikoRuleset(), beatmap); protected override Ruleset CreateRuleset() => new TaikoRuleset(); } diff --git a/osu.Game.Rulesets.Taiko/Difficulty/Preprocessing/TaikoDifficultyHitObject.cs b/osu.Game.Rulesets.Taiko/Difficulty/Preprocessing/TaikoDifficultyHitObject.cs new file mode 100644 index 0000000000..4d63d81663 --- /dev/null +++ b/osu.Game.Rulesets.Taiko/Difficulty/Preprocessing/TaikoDifficultyHitObject.cs @@ -0,0 +1,20 @@ +// Copyright (c) ppy Pty Ltd . Licensed under the MIT Licence. +// See the LICENCE file in the repository root for full licence text. + +using osu.Game.Rulesets.Difficulty.Preprocessing; +using osu.Game.Rulesets.Objects; +using osu.Game.Rulesets.Taiko.Objects; + +namespace osu.Game.Rulesets.Taiko.Difficulty.Preprocessing +{ + public class TaikoDifficultyHitObject : DifficultyHitObject + { + public readonly bool HasTypeChange; + + public TaikoDifficultyHitObject(HitObject hitObject, HitObject lastObject, double timeRate) + : base(hitObject, lastObject, timeRate) + { + HasTypeChange = lastObject is RimHit != hitObject is RimHit; + } + } +} diff --git a/osu.Game.Rulesets.Taiko/Difficulty/Skills/Strain.cs b/osu.Game.Rulesets.Taiko/Difficulty/Skills/Strain.cs new file mode 100644 index 0000000000..c77e6a3afd --- /dev/null +++ b/osu.Game.Rulesets.Taiko/Difficulty/Skills/Strain.cs @@ -0,0 +1,90 @@ +// Copyright (c) ppy Pty Ltd . Licensed under the MIT Licence. +// See the LICENCE file in the repository root for full licence text. + +using System; +using osu.Game.Rulesets.Difficulty.Preprocessing; +using osu.Game.Rulesets.Difficulty.Skills; +using osu.Game.Rulesets.Taiko.Difficulty.Preprocessing; +using osu.Game.Rulesets.Taiko.Objects; + +namespace osu.Game.Rulesets.Taiko.Difficulty.Skills +{ + public class Strain : Skill + { + private const double rhythm_change_base_threshold = 0.2; + private const double rhythm_change_base = 2.0; + + protected override double SkillMultiplier => 1; + protected override double StrainDecayBase => 0.3; + + private ColourSwitch lastColourSwitch = ColourSwitch.None; + + private int sameTypeCount; + + protected override double StrainValueOf(DifficultyHitObject current) + { + double addition = 1; + + // We get an extra addition if we are not a slider or spinner + if (Previous[0].BaseObject is Hit && current.BaseObject is Hit && current.BaseObject.StartTime - Previous[0].BaseObject.StartTime < 1000) + { + if (hasRhythmChange(current)) + addition += 1; + + if (hasColourChange(current)) + addition += 0.75; + } + + double additionFactor = 1; + + // Scale the addition factor linearly from 0.4 to 1 for DeltaTime from 0 to 50 + if (current.DeltaTime < 50) + additionFactor = 0.4 + 0.6 * current.DeltaTime / 50; + + return additionFactor * addition; + } + + private bool hasRhythmChange(DifficultyHitObject current) + { + // We don't want a division by zero if some random mapper decides to put two HitObjects at the same time. + if (current.DeltaTime == 0 || Previous[0].DeltaTime == 0) + return false; + + double timeElapsedRatio = Math.Max(Previous[0].DeltaTime / current.DeltaTime, current.DeltaTime / Previous[0].DeltaTime); + + if (timeElapsedRatio >= 8) + return false; + + double difference = Math.Log(timeElapsedRatio, rhythm_change_base) % 1.0; + + return difference > rhythm_change_base_threshold && difference < 1 - rhythm_change_base_threshold; + } + + private bool hasColourChange(DifficultyHitObject current) + { + var taikoCurrent = (TaikoDifficultyHitObject)current; + + if (!taikoCurrent.HasTypeChange) + { + sameTypeCount++; + return false; + } + + var oldColourSwitch = lastColourSwitch; + var newColourSwitch = sameTypeCount % 2 == 0 ? ColourSwitch.Even : ColourSwitch.Odd; + + lastColourSwitch = newColourSwitch; + sameTypeCount = 1; + + // We only want a bonus if the parity of the color switch changes + return oldColourSwitch != ColourSwitch.None && oldColourSwitch != newColourSwitch; + } + + private enum ColourSwitch + { + None, + Even, + Odd + } + } +} diff --git a/osu.Game.Rulesets.Taiko/Difficulty/TaikoDifficultyAttributes.cs b/osu.Game.Rulesets.Taiko/Difficulty/TaikoDifficultyAttributes.cs index 3770f9601a..07721e2ac5 100644 --- a/osu.Game.Rulesets.Taiko/Difficulty/TaikoDifficultyAttributes.cs +++ b/osu.Game.Rulesets.Taiko/Difficulty/TaikoDifficultyAttributes.cs @@ -11,8 +11,8 @@ namespace osu.Game.Rulesets.Taiko.Difficulty public double GreatHitWindow; public int MaxCombo; - public TaikoDifficultyAttributes(Mod[] mods, double starRating) - : base(mods, starRating) + public TaikoDifficultyAttributes(Mod[] mods) + : base(mods) { } } diff --git a/osu.Game.Rulesets.Taiko/Difficulty/TaikoDifficultyCalculator.cs b/osu.Game.Rulesets.Taiko/Difficulty/TaikoDifficultyCalculator.cs new file mode 100644 index 0000000000..3d18274bba --- /dev/null +++ b/osu.Game.Rulesets.Taiko/Difficulty/TaikoDifficultyCalculator.cs @@ -0,0 +1,56 @@ +// Copyright (c) ppy Pty Ltd . Licensed under the MIT Licence. +// See the LICENCE file in the repository root for full licence text. + +using System.Collections.Generic; +using System.Linq; +using osu.Game.Beatmaps; +using osu.Game.Rulesets.Difficulty; +using osu.Game.Rulesets.Difficulty.Preprocessing; +using osu.Game.Rulesets.Difficulty.Skills; +using osu.Game.Rulesets.Mods; +using osu.Game.Rulesets.Taiko.Difficulty.Preprocessing; +using osu.Game.Rulesets.Taiko.Difficulty.Skills; +using osu.Game.Rulesets.Taiko.Mods; +using osu.Game.Rulesets.Taiko.Objects; + +namespace osu.Game.Rulesets.Taiko.Difficulty +{ + public class TaikoDifficultyCalculator : DifficultyCalculator + { + private const double star_scaling_factor = 0.018; + + public TaikoDifficultyCalculator(Ruleset ruleset, WorkingBeatmap beatmap) + : base(ruleset, beatmap) + { + } + + protected override void PopulateAttributes(DifficultyAttributes attributes, IBeatmap beatmap, Skill[] skills, double timeRate) + { + var taikoAttributes = (TaikoDifficultyAttributes)attributes; + + taikoAttributes.StarRating = skills.Single().DifficultyValue() * star_scaling_factor; + + // Todo: This int cast is temporary to achieve 1:1 results with osu!stable, and should be removed in the future + taikoAttributes.GreatHitWindow = (int)(beatmap.HitObjects.First().HitWindows.Great / 2) / timeRate; + taikoAttributes.MaxCombo = beatmap.HitObjects.Count(h => h is Hit); + } + + protected override IEnumerable CreateDifficultyHitObjects(IBeatmap beatmap, double timeRate) + { + for (int i = 1; i < beatmap.HitObjects.Count; i++) + yield return new TaikoDifficultyHitObject(beatmap.HitObjects[i], beatmap.HitObjects[i - 1], timeRate); + } + + protected override Skill[] CreateSkills() => new Skill[] { new Strain() }; + + protected override DifficultyAttributes CreateDifficultyAttributes(Mod[] mods) => new TaikoDifficultyAttributes(mods); + + protected override Mod[] DifficultyAdjustmentMods => new Mod[] + { + new TaikoModDoubleTime(), + new TaikoModHalfTime(), + new TaikoModEasy(), + new TaikoModHardRock(), + }; + } +} diff --git a/osu.Game.Rulesets.Taiko/Difficulty/TaikoLegacyDifficultyCalculator.cs b/osu.Game.Rulesets.Taiko/Difficulty/TaikoLegacyDifficultyCalculator.cs deleted file mode 100644 index 650b367e34..0000000000 --- a/osu.Game.Rulesets.Taiko/Difficulty/TaikoLegacyDifficultyCalculator.cs +++ /dev/null @@ -1,144 +0,0 @@ -// Copyright (c) ppy Pty Ltd . 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.Taiko.Mods; -using osu.Game.Rulesets.Taiko.Objects; - -namespace osu.Game.Rulesets.Taiko.Difficulty -{ - internal class TaikoLegacyDifficultyCalculator : LegacyDifficultyCalculator - { - private const double star_scaling_factor = 0.04125; - - /// - /// In milliseconds. For difficulty calculation we will only look at the highest strain value in each time interval of size STRAIN_STEP. - /// This is to eliminate higher influence of stream over aim by simply having more HitObjects with high strain. - /// The higher this value, the less strains there will be, indirectly giving long beatmaps an advantage. - /// - private const double strain_step = 400; - - /// - /// The weighting of each strain value decays to this number * it's previous value - /// - private const double decay_weight = 0.9; - - public TaikoLegacyDifficultyCalculator(Ruleset ruleset, WorkingBeatmap beatmap) - : base(ruleset, beatmap) - { - } - - protected override DifficultyAttributes Calculate(IBeatmap beatmap, Mod[] mods, double timeRate) - { - if (!beatmap.HitObjects.Any()) - return new TaikoDifficultyAttributes(mods, 0); - - var difficultyHitObjects = new List(); - - foreach (var hitObject in beatmap.HitObjects) - difficultyHitObjects.Add(new TaikoHitObjectDifficulty((TaikoHitObject)hitObject)); - - // Sort DifficultyHitObjects by StartTime of the HitObjects - just to make sure. - difficultyHitObjects.Sort((a, b) => a.BaseHitObject.StartTime.CompareTo(b.BaseHitObject.StartTime)); - - if (!calculateStrainValues(difficultyHitObjects, timeRate)) - return new TaikoDifficultyAttributes(mods, 0); - - double starRating = calculateDifficulty(difficultyHitObjects, timeRate) * star_scaling_factor; - - return new TaikoDifficultyAttributes(mods, starRating) - { - // Todo: This int cast is temporary to achieve 1:1 results with osu!stable, and should be remoevd in the future - GreatHitWindow = (int)(beatmap.HitObjects.First().HitWindows.Great / 2) / timeRate, - MaxCombo = beatmap.HitObjects.Count(h => h is Hit) - }; - } - - private bool calculateStrainValues(List objects, double timeRate) - { - // Traverse hitObjects in pairs to calculate the strain value of NextHitObject from the strain value of CurrentHitObject and environment. - using (var hitObjectsEnumerator = objects.GetEnumerator()) - { - if (!hitObjectsEnumerator.MoveNext()) return false; - - TaikoHitObjectDifficulty current = hitObjectsEnumerator.Current; - - // First hitObject starts at strain 1. 1 is the default for strain values, so we don't need to set it here. See DifficultyHitObject. - while (hitObjectsEnumerator.MoveNext()) - { - var next = hitObjectsEnumerator.Current; - next?.CalculateStrains(current, timeRate); - current = next; - } - - return true; - } - } - - private double calculateDifficulty(List objects, double timeRate) - { - double actualStrainStep = strain_step * timeRate; - - // Find the highest strain value within each strain step - List highestStrains = new List(); - double intervalEndTime = actualStrainStep; - double maximumStrain = 0; // We need to keep track of the maximum strain in the current interval - - TaikoHitObjectDifficulty previousHitObject = null; - foreach (var hitObject in objects) - { - // While we are beyond the current interval push the currently available maximum to our strain list - while (hitObject.BaseHitObject.StartTime > intervalEndTime) - { - highestStrains.Add(maximumStrain); - - // The maximum strain of the next interval is not zero by default! We need to take the last hitObject we encountered, take its strain and apply the decay - // until the beginning of the next interval. - if (previousHitObject == null) - { - maximumStrain = 0; - } - else - { - double decay = Math.Pow(TaikoHitObjectDifficulty.DECAY_BASE, (intervalEndTime - previousHitObject.BaseHitObject.StartTime) / 1000); - maximumStrain = previousHitObject.Strain * decay; - } - - // Go to the next time interval - intervalEndTime += actualStrainStep; - } - - // Obtain maximum strain - maximumStrain = Math.Max(hitObject.Strain, maximumStrain); - - previousHitObject = hitObject; - } - - // Build the weighted sum over the highest strains for each interval - double difficulty = 0; - double weight = 1; - highestStrains.Sort((a, b) => b.CompareTo(a)); // Sort from highest to lowest strain. - - foreach (double strain in highestStrains) - { - difficulty += weight * strain; - weight *= decay_weight; - } - - return difficulty; - } - - protected override Mod[] DifficultyAdjustmentMods => new Mod[] - { - new TaikoModDoubleTime(), - new TaikoModHalfTime(), - new TaikoModEasy(), - new TaikoModHardRock(), - }; - } -} diff --git a/osu.Game.Rulesets.Taiko/Objects/TaikoHitObjectDifficulty.cs b/osu.Game.Rulesets.Taiko/Objects/TaikoHitObjectDifficulty.cs deleted file mode 100644 index 46dd7aa87f..0000000000 --- a/osu.Game.Rulesets.Taiko/Objects/TaikoHitObjectDifficulty.cs +++ /dev/null @@ -1,127 +0,0 @@ -// Copyright (c) ppy Pty Ltd . Licensed under the MIT Licence. -// See the LICENCE file in the repository root for full licence text. - -using System; - -namespace osu.Game.Rulesets.Taiko.Objects -{ - internal class TaikoHitObjectDifficulty - { - /// - /// Factor by how much individual / overall strain decays per second. - /// - /// - /// These values are results of tweaking a lot and taking into account general feedback. - /// - internal const double DECAY_BASE = 0.30; - - private const double type_change_bonus = 0.75; - private const double rhythm_change_bonus = 1.0; - private const double rhythm_change_base_threshold = 0.2; - private const double rhythm_change_base = 2.0; - - internal TaikoHitObject BaseHitObject; - - /// - /// Measures note density in a way - /// - internal double Strain = 1; - - private double timeElapsed; - private int sameTypeSince = 1; - - private bool isRim => BaseHitObject is RimHit; - - public TaikoHitObjectDifficulty(TaikoHitObject baseHitObject) - { - BaseHitObject = baseHitObject; - } - - internal void CalculateStrains(TaikoHitObjectDifficulty previousHitObject, double timeRate) - { - // Rather simple, but more specialized things are inherently inaccurate due to the big difference playstyles and opinions make. - // See Taiko feedback thread. - timeElapsed = (BaseHitObject.StartTime - previousHitObject.BaseHitObject.StartTime) / timeRate; - double decay = Math.Pow(DECAY_BASE, timeElapsed / 1000); - - double addition = 1; - - // Only if we are no slider or spinner we get an extra addition - if (previousHitObject.BaseHitObject is Hit && BaseHitObject is Hit - && BaseHitObject.StartTime - previousHitObject.BaseHitObject.StartTime < 1000) // And we only want to check out hitobjects which aren't so far in the past - { - addition += typeChangeAddition(previousHitObject); - addition += rhythmChangeAddition(previousHitObject); - } - - double additionFactor = 1.0; - // Scale AdditionFactor linearly from 0.4 to 1 for TimeElapsed from 0 to 50 - if (timeElapsed < 50.0) - additionFactor = 0.4 + 0.6 * timeElapsed / 50.0; - - Strain = previousHitObject.Strain * decay + addition * additionFactor; - } - - private TypeSwitch lastTypeSwitchEven = TypeSwitch.None; - private double typeChangeAddition(TaikoHitObjectDifficulty previousHitObject) - { - // If we don't have the same hit type, trigger a type change! - if (previousHitObject.isRim != isRim) - { - lastTypeSwitchEven = previousHitObject.sameTypeSince % 2 == 0 ? TypeSwitch.Even : TypeSwitch.Odd; - - // We only want a bonus if the parity of the type switch changes! - switch (previousHitObject.lastTypeSwitchEven) - { - case TypeSwitch.Even: - if (lastTypeSwitchEven == TypeSwitch.Odd) - return type_change_bonus; - break; - case TypeSwitch.Odd: - if (lastTypeSwitchEven == TypeSwitch.Even) - return type_change_bonus; - break; - } - } - // No type change? Increment counter and keep track of last type switch - else - { - lastTypeSwitchEven = previousHitObject.lastTypeSwitchEven; - sameTypeSince = previousHitObject.sameTypeSince + 1; - } - - return 0; - } - - private double rhythmChangeAddition(TaikoHitObjectDifficulty previousHitObject) - { - // We don't want a division by zero if some random mapper decides to put 2 HitObjects at the same time. - if (timeElapsed == 0 || previousHitObject.timeElapsed == 0) - return 0; - - double timeElapsedRatio = Math.Max(previousHitObject.timeElapsed / timeElapsed, timeElapsed / previousHitObject.timeElapsed); - - if (timeElapsedRatio >= 8) - return 0; - - double difference = Math.Log(timeElapsedRatio, rhythm_change_base) % 1.0; - - if (isWithinChangeThreshold(difference)) - return rhythm_change_bonus; - - return 0; - } - - private bool isWithinChangeThreshold(double value) - { - return value > rhythm_change_base_threshold && value < 1 - rhythm_change_base_threshold; - } - - private enum TypeSwitch - { - None, - Even, - Odd - } - } -} diff --git a/osu.Game.Rulesets.Taiko/TaikoRuleset.cs b/osu.Game.Rulesets.Taiko/TaikoRuleset.cs index 77a53858fe..b4becae7c2 100644 --- a/osu.Game.Rulesets.Taiko/TaikoRuleset.cs +++ b/osu.Game.Rulesets.Taiko/TaikoRuleset.cs @@ -110,7 +110,7 @@ namespace osu.Game.Rulesets.Taiko public override Drawable CreateIcon() => new SpriteIcon { Icon = FontAwesome.fa_osu_taiko_o }; - public override LegacyDifficultyCalculator CreateDifficultyCalculator(WorkingBeatmap beatmap) => new TaikoLegacyDifficultyCalculator(this, beatmap); + public override LegacyDifficultyCalculator CreateDifficultyCalculator(WorkingBeatmap beatmap) => new TaikoDifficultyCalculator(this, beatmap); public override PerformanceCalculator CreatePerformanceCalculator(WorkingBeatmap beatmap, ScoreInfo score) => new TaikoPerformanceCalculator(this, beatmap, score); diff --git a/osu.Game.Rulesets.Taiko/osu.Game.Rulesets.Taiko.csproj b/osu.Game.Rulesets.Taiko/osu.Game.Rulesets.Taiko.csproj index 002d6a7e8d..563ed2e7ca 100644 --- a/osu.Game.Rulesets.Taiko/osu.Game.Rulesets.Taiko.csproj +++ b/osu.Game.Rulesets.Taiko/osu.Game.Rulesets.Taiko.csproj @@ -10,4 +10,7 @@ + + + \ No newline at end of file