more clean-up

osu.Game.Rulesets.Osu/Difficulty/OsuDifficultyAttributes.cs

@@ -61,9 +61,6 @@ namespace osu.Game.Rulesets.Osu.Difficulty
         [JsonProperty("low_ar_difficult_strain_count")]
         public double LowArDifficultStrainCount { get; set; }
 
-        [JsonProperty("hidden_difficult_strain_count")]
-        public double HiddenDifficultStrainCount { get; set; }
-
         /// <summary>
         /// The perceived approach rate inclusive of rate-adjusting mods (DT/HT/etc).
         /// </summary>

osu.Game.Rulesets.Osu/Difficulty/OsuDifficultyCalculator.cs

@@ -22,7 +22,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty
 {
     public class OsuDifficultyCalculator : DifficultyCalculator
     {
-        public const double DIFFICULTY_MULTIPLIER = 0.0675;
+        private const double difficulty_multiplier = 0.0675;
         public const double SUM_POWER = 1.1;
         public const double FL_SUM_POWER = 1.5;
         public override int Version => 20241007;
@@ -37,17 +37,17 @@ namespace osu.Game.Rulesets.Osu.Difficulty
             if (beatmap.HitObjects.Count == 0)
                 return new OsuDifficultyAttributes { Mods = mods };
 
-            double aimRating = Math.Sqrt(skills[0].DifficultyValue()) * DIFFICULTY_MULTIPLIER;
+            double aimRating = Math.Sqrt(skills[0].DifficultyValue()) * difficulty_multiplier;
-            double aimRatingNoSliders = Math.Sqrt(skills[1].DifficultyValue()) * DIFFICULTY_MULTIPLIER;
+            double aimRatingNoSliders = Math.Sqrt(skills[1].DifficultyValue()) * difficulty_multiplier;
-            double speedRating = Math.Sqrt(skills.OfType<Speed>().First().DifficultyValue()) * DIFFICULTY_MULTIPLIER;
+            double speedRating = Math.Sqrt(skills.OfType<Speed>().First().DifficultyValue()) * difficulty_multiplier;
             double speedNotes = skills.OfType<Speed>().First().RelevantNoteCount();
 
-            double flashlightRating = Math.Sqrt(skills.OfType<Flashlight>().First().DifficultyValue()) * DIFFICULTY_MULTIPLIER;
+            double flashlightRating = Math.Sqrt(skills.OfType<Flashlight>().First().DifficultyValue()) * difficulty_multiplier;
-            double readingLowARRating = Math.Sqrt(skills.OfType<ReadingLowAR>().First().DifficultyValue()) * DIFFICULTY_MULTIPLIER;
+            double readingLowARRating = Math.Sqrt(skills.OfType<ReadingLowAR>().First().DifficultyValue()) * difficulty_multiplier;
 
             double sliderFactor = aimRating > 0 ? aimRatingNoSliders / aimRating : 1;
 
-            double aimDifficultyStrainCount = skills[0].CountTopWeightedStrains();
+            double aimDifficultyStrainCount = skills.OfType<Aim>().First().CountTopWeightedStrains();
             double speedDifficultyStrainCount = skills.OfType<Speed>().First().CountTopWeightedStrains();
             double lowArDifficultyStrainCount = skills.OfType<ReadingLowAR>().First().CountTopWeightedStrains();
 
@@ -62,7 +62,6 @@ namespace osu.Game.Rulesets.Osu.Difficulty
             {
                 aimRating *= 0.9;
                 speedRating = 0.0;
-                readingLowARRating *= 0.95;
                 flashlightRating *= 0.7;
                 readingLowARRating *= 0.95;
             }

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

@@ -1,6 +1,7 @@
 // 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 osu.Game.Rulesets.Difficulty.Preprocessing;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Osu.Difficulty.Evaluators;
@@ -20,17 +21,21 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
 
         private readonly bool withSliders;
 
-        protected double CurrentStrain;
+        private double currentStrain;
-        protected double SkillMultiplier => 25.3;
 
-        protected override double CalculateInitialStrain(double time, DifficultyHitObject current) => CurrentStrain * StrainDecay(time - current.Previous(0).StartTime);
+        private double skillMultiplier => 25.3;
+        private double strainDecayBase => 0.15;
+
+        private double strainDecay(double ms) => Math.Pow(strainDecayBase, ms / 1000);
+
+        protected override double CalculateInitialStrain(double time, DifficultyHitObject current) => currentStrain * strainDecay(time - current.Previous(0).StartTime);
 
         protected override double StrainValueAt(DifficultyHitObject current)
         {
-            CurrentStrain *= StrainDecay(current.DeltaTime);
+            currentStrain *= strainDecay(current.DeltaTime);
-            CurrentStrain += AimEvaluator.EvaluateDifficultyOf(current, withSliders) * SkillMultiplier;
+            currentStrain += AimEvaluator.EvaluateDifficultyOf(current, withSliders) * skillMultiplier;
 
-            return CurrentStrain;
+            return currentStrain;
         }
     }
 }

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

@@ -23,10 +23,6 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
         /// </summary>
         protected virtual double ReducedStrainBaseline => 0.75;
 
-        protected virtual double StrainDecayBase => 0.15;
-
-        protected double StrainDecay(double ms) => Math.Pow(StrainDecayBase, ms / 1000);
-
         protected OsuStrainSkill(Mod[] mods)
             : base(mods)
         {
@@ -61,9 +57,6 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
             return difficulty;
         }
 
-        /// <summary>
-        /// Converts difficulty value from <see cref="OsuDifficultyAttributes"/> to base performance.
-        /// </summary>
         public static double DifficultyToPerformance(double difficulty) => Math.Pow(5.0 * Math.Max(1.0, difficulty / 0.0675) - 4.0, 3.0) / 100000.0;
     }
 }

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

@@ -28,7 +28,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
 
         private double currentDensityAimStrain = 0;
 
-        public override void Process(DifficultyHitObject current)
+        protected override double StrainValueAt(DifficultyHitObject current)
         {
             double densityReadingDifficulty = ReadingEvaluator.EvaluateDifficultyOf(current);
             double densityAimingFactor = ReadingEvaluator.EvaluateAimingDensityFactorOf(current);
@@ -37,22 +37,11 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
             currentDensityAimStrain += densityAimingFactor * AimEvaluator.EvaluateDifficultyOf(current, true) * aimComponentMultiplier;
 
             double totalDensityDifficulty = (currentDensityAimStrain + densityReadingDifficulty) * skillMultiplier;
-
+            return totalDensityDifficulty;
-            ObjectStrains.Add(totalDensityDifficulty);
-
-            if (current.Index == 0)
-                CurrentSectionEnd = Math.Ceiling(current.StartTime / SectionLength) * SectionLength;
-
-            while (current.StartTime > CurrentSectionEnd)
-            {
-                StrainPeaks.Add(CurrentSectionPeak);
-                CurrentSectionPeak = 0;
-                CurrentSectionEnd += SectionLength;
-            }
-
-            CurrentSectionPeak = Math.Max(totalDensityDifficulty, CurrentSectionPeak);
         }
 
+        protected override double CalculateInitialStrain(double time, DifficultyHitObject current) => 0;
+
         private double reducedNoteCount => 5;
         private double reducedNoteBaseline => 0.7;
         public override double DifficultyValue()
@@ -85,15 +74,5 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
         public static double DifficultyToPerformance(double difficulty) => Math.Max(
             Math.Max(Math.Pow(difficulty, 1.5) * 20, Math.Pow(difficulty, 2) * 17.0),
             Math.Max(Math.Pow(difficulty, 3) * 10.5, Math.Pow(difficulty, 4) * 6.00));
-
-        protected override double StrainValueAt(DifficultyHitObject current)
-        {
-            throw new NotImplementedException();
-        }
-
-        protected override double CalculateInitialStrain(double time, DifficultyHitObject current)
-        {
-            throw new NotImplementedException();
-        }
     }
 }

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

@@ -15,11 +15,11 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
     /// </summary>
     public class Speed : OsuStrainSkill
     {
-        protected double SkillMultiplier => 1.430;
+        private double skillMultiplier => 1.430;
-        protected override double StrainDecayBase => 0.3;
+        private double strainDecayBase => 0.3;
 
-        protected double CurrentStrain;
+        private double currentStrain;
-        protected double CurrentRhythm;
+        private double currentRhythm;
 
         protected override int ReducedSectionCount => 5;
 
@@ -28,17 +28,18 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
         {
         }
 
-        protected override double CalculateInitialStrain(double time, DifficultyHitObject current) => (CurrentStrain * CurrentRhythm) * StrainDecay(time - current.Previous(0).StartTime);
+        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)
         {
-            OsuDifficultyHitObject currODHO = (OsuDifficultyHitObject)current;
+            currentStrain *= strainDecay(((OsuDifficultyHitObject)current).StrainTime);
+            currentStrain += SpeedEvaluator.EvaluateDifficultyOf(current) * skillMultiplier;
 
-            CurrentStrain *= StrainDecay(currODHO.StrainTime);
+            currentRhythm = RhythmEvaluator.EvaluateDifficultyOf(current);
-            CurrentStrain += SpeedEvaluator.EvaluateDifficultyOf(current) * SkillMultiplier;
 
-            CurrentRhythm = RhythmEvaluator.EvaluateDifficultyOf(current);
+            double totalStrain = currentStrain * currentRhythm;
-            double totalStrain = CurrentStrain * CurrentRhythm;
 
             return totalStrain;
         }

osu.Game/Rulesets/Difficulty/Skills/Skill.cs

@@ -1,9 +1,7 @@
 // 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.Rulesets.Difficulty.Preprocessing;
 using osu.Game.Rulesets.Mods;
 
@@ -29,8 +27,6 @@ namespace osu.Game.Rulesets.Difficulty.Skills
             this.mods = mods;
         }
 
-        protected List<double> ObjectStrains = new List<double>();
-
         /// <summary>
         /// Process a <see cref="DifficultyHitObject"/>.
         /// </summary>
@@ -41,23 +37,5 @@ namespace osu.Game.Rulesets.Difficulty.Skills
         /// Returns the calculated difficulty value representing all <see cref="DifficultyHitObject"/>s that have been processed up to this point.
         /// </summary>
         public abstract double DifficultyValue();
-
-        /// <summary>
-        /// Calculates the number of strains weighted against the top strain.
-        /// The result is scaled by clock rate as it affects the total number of strains.
-        /// </summary>
-        public virtual double CountTopWeightedStrains()
-        {
-            if (ObjectStrains.Count == 0)
-                return 0.0;
-
-            double consistentTopStrain = DifficultyValue() / 10; // What would the top strain be if all strain values were identical
-
-            if (consistentTopStrain == 0)
-                return ObjectStrains.Count;
-
-            // Use a weighted sum of all strains. Constants are arbitrary and give nice values
-            return ObjectStrains.Sum(s => 1.1 / (1 + Math.Exp(-10 * (s / consistentTopStrain - 0.88))));
-        }
     }
 }

osu.Game/Rulesets/Difficulty/Skills/StrainSkill.cs

@@ -20,21 +20,21 @@ namespace osu.Game.Rulesets.Difficulty.Skills
         /// </summary>
         protected virtual double DecayWeight => 0.9;
 
-        protected StrainSkill(Mod[] mods)
-            : base(mods)
-        {
-        }
-
         /// <summary>
         /// The length of each strain section.
         /// </summary>
         protected virtual int SectionLength => 400;
 
-        public double CurrentSectionPeak { get; protected set; } // We also keep track of the peak level in the current section.
+        private double currentSectionPeak; // We also keep track of the peak strain level in the current section.
+        private double currentSectionEnd;
 
-        protected double CurrentSectionEnd;
+        private readonly List<double> strainPeaks = new List<double>();
+        protected readonly List<double> ObjectStrains = new List<double>(); // Store individual strains
 
-        protected readonly List<double> StrainPeaks = new List<double>();
+        protected StrainSkill(Mod[] mods)
+            : base(mods)
+        {
+        }
 
         /// <summary>
         /// Returns the strain value at <see cref="DifficultyHitObject"/>. This value is calculated with or without respect to previous objects.
@@ -48,28 +48,46 @@ namespace osu.Game.Rulesets.Difficulty.Skills
         {
             // The first object doesn't generate a strain, so we begin with an incremented section end
             if (current.Index == 0)
-                CurrentSectionEnd = Math.Ceiling(current.StartTime / SectionLength) * SectionLength;
+                currentSectionEnd = Math.Ceiling(current.StartTime / SectionLength) * SectionLength;
 
-            while (current.StartTime > CurrentSectionEnd)
+            while (current.StartTime > currentSectionEnd)
             {
                 saveCurrentPeak();
-                startNewSectionFrom(CurrentSectionEnd, current);
+                startNewSectionFrom(currentSectionEnd, current);
-                CurrentSectionEnd += SectionLength;
+                currentSectionEnd += SectionLength;
             }
 
             double strain = StrainValueAt(current);
-            CurrentSectionPeak = Math.Max(strain, CurrentSectionPeak);
+            currentSectionPeak = Math.Max(strain, currentSectionPeak);
 
             // Store the strain value for the object
             ObjectStrains.Add(strain);
         }
 
+        /// <summary>
+        /// Calculates the number of strains weighted against the top strain.
+        /// The result is scaled by clock rate as it affects the total number of strains.
+        /// </summary>
+        public virtual double CountTopWeightedStrains()
+        {
+            if (ObjectStrains.Count == 0)
+                return 0.0;
+
+            double consistentTopStrain = DifficultyValue() / 10; // What would the top strain be if all strain values were identical
+
+            if (consistentTopStrain == 0)
+                return ObjectStrains.Count;
+
+            // Use a weighted sum of all strains. Constants are arbitrary and give nice values
+            return ObjectStrains.Sum(s => 1.1 / (1 + Math.Exp(-10 * (s / consistentTopStrain - 0.88))));
+        }
+
         /// <summary>
         /// Saves the current peak strain level to the list of strain peaks, which will be used to calculate an overall difficulty.
         /// </summary>
         private void saveCurrentPeak()
         {
-            StrainPeaks.Add(CurrentSectionPeak);
+            strainPeaks.Add(currentSectionPeak);
         }
 
         /// <summary>
@@ -81,7 +99,7 @@ namespace osu.Game.Rulesets.Difficulty.Skills
         {
             // The maximum strain of the new section is not zero by default
             // This means we need to capture the strain level at the beginning of the new section, and use that as the initial peak level.
-            CurrentSectionPeak = CalculateInitialStrain(time, current);
+            currentSectionPeak = CalculateInitialStrain(time, current);
         }
 
         /// <summary>
@@ -93,9 +111,10 @@ namespace osu.Game.Rulesets.Difficulty.Skills
         protected abstract double CalculateInitialStrain(double time, DifficultyHitObject current);
 
         /// <summary>
-        /// Returns a live enumerable of the difficulties
+        /// Returns a live enumerable of the peak strains for each <see cref="SectionLength"/> section of the beatmap,
+        /// including the peak of the current section.
         /// </summary>
-        public virtual IEnumerable<double> GetCurrentStrainPeaks() => StrainPeaks.Append(CurrentSectionPeak);
+        public IEnumerable<double> GetCurrentStrainPeaks() => strainPeaks.Append(currentSectionPeak);
 
         /// <summary>
         /// Returns the calculated difficulty value representing all <see cref="DifficultyHitObject"/>s that have been processed up to this point.