Do not use statics

osu.Game.Rulesets.Taiko/Difficulty/Preprocessing/TaikoDifficultyHitObject.cs

@@ -23,7 +23,7 @@ namespace osu.Game.Rulesets.Taiko.Difficulty.Preprocessing
         public readonly int n;
         private int counter = 0;
 
-        public TaikoDifficultyHitObject(HitObject hitObject, HitObject lastObject, HitObject lastLastObject, double clockRate)
+        public TaikoDifficultyHitObject(HitObject hitObject, HitObject lastObject, HitObject lastLastObject, double clockRate, TaikoDifficultyHitObjectRhythm rhythm)
             : base(hitObject, lastObject, clockRate)
         {
             var lastHit = lastObject as Hit;
@@ -31,11 +31,11 @@ namespace osu.Game.Rulesets.Taiko.Difficulty.Preprocessing
 
             NoteLength = DeltaTime;
             double prevLength = (lastObject.StartTime - lastLastObject.StartTime) / clockRate;
-            Rhythm = TaikoDifficultyHitObjectRhythm.GetClosest(NoteLength / prevLength);
+            Rhythm = rhythm.GetClosest(NoteLength / prevLength);
             RhythmID = Rhythm.ID;
             HasTypeChange = lastHit?.Type != currentHit?.Type;
             IsKat = lastHit?.Type == HitType.Rim;
-            HasTimingChange = !TaikoDifficultyHitObjectRhythm.IsRepeat(RhythmID);
+            HasTimingChange = !rhythm.IsRepeat(RhythmID);
 
             n = counter;
             counter++;

osu.Game.Rulesets.Taiko/Difficulty/Preprocessing/TaikoDifficultyHitObjectRhythm.cs

@@ -7,18 +7,36 @@ namespace osu.Game.Rulesets.Taiko.Difficulty.Preprocessing
 {
     public class TaikoDifficultyHitObjectRhythm
     {
-
+        private readonly TaikoDifficultyHitObjectRhythm[] commonRhythms;
-        private static TaikoDifficultyHitObjectRhythm[] commonRhythms;
+        private readonly TaikoDifficultyHitObjectRhythm constRhythm;
-        private static TaikoDifficultyHitObjectRhythm constRhythm;
+        private int constRhythmID;
-        private static int constRhythmID;
 
         public int ID = 0;
         public readonly double Difficulty;
         private readonly double ratio;
 
-        private static void initialiseCommonRhythms()
+        public bool IsRepeat()
         {
+            return ID == constRhythmID;
+        }
 
+        public bool IsRepeat(int id)
+        {
+            return id == constRhythmID;
+        }
+
+        public bool IsSpeedup()
+        {
+            return ratio < 1.0;
+        }
+
+        public bool IsLargeSpeedup()
+        {
+            return ratio < 0.49;
+        }
+
+        public TaikoDifficultyHitObjectRhythm()
+        {
             /*
 
                 ALCHYRS CODE
@@ -40,8 +58,7 @@ namespace osu.Game.Rulesets.Taiko.Difficulty.Preprocessing
 
             */
 
-
+            commonRhythms = new[]
-            commonRhythms = new TaikoDifficultyHitObjectRhythm[]
             {
                 new TaikoDifficultyHitObjectRhythm(1, 1, 0.1),
                 new TaikoDifficultyHitObjectRhythm(2, 1, 0.3),
@@ -61,33 +78,6 @@ namespace osu.Game.Rulesets.Taiko.Difficulty.Preprocessing
 
             constRhythmID = 0;
             constRhythm = commonRhythms[constRhythmID];
-
-        }
-
-        public bool IsRepeat()
-        {
-            return ID == constRhythmID;
-        }
-
-        public static bool IsRepeat(int id)
-        {
-            return id == constRhythmID;
-        }
-
-        public bool IsSpeedup()
-        {
-            return ratio < 1.0;
-        }
-
-        public bool IsLargeSpeedup()
-        {
-            return ratio < 0.49;
-        }
-
-        private TaikoDifficultyHitObjectRhythm(double ratio, double difficulty)
-        {
-            this.ratio = ratio;
-            this.Difficulty = difficulty;
         }
 
         private TaikoDifficultyHitObjectRhythm(int numerator, int denominator, double difficulty)
@@ -97,13 +87,8 @@ namespace osu.Game.Rulesets.Taiko.Difficulty.Preprocessing
         }
 
         // Code is inefficient - we are searching exhaustively through the sorted list commonRhythms
-        public static TaikoDifficultyHitObjectRhythm GetClosest(double ratio)
+        public TaikoDifficultyHitObjectRhythm GetClosest(double ratio)
         {
-            if (commonRhythms == null)
-            {
-                initialiseCommonRhythms();
-            }
-
             TaikoDifficultyHitObjectRhythm closestRhythm = commonRhythms[0];
             double closestDistance = Double.MaxValue;
 
@@ -117,8 +102,6 @@ namespace osu.Game.Rulesets.Taiko.Difficulty.Preprocessing
             }
 
             return closestRhythm;
-
         }
-
     }
 }

osu.Game.Rulesets.Taiko/Difficulty/Skills/Colour.cs

@@ -17,12 +17,13 @@ namespace osu.Game.Rulesets.Taiko.Difficulty.Skills
         private ColourSwitch lastColourSwitch = ColourSwitch.None;
         private int sameColourCount = 1;
 
-        private int[] previousDonLengths = { 0, 0 }, previousKatLengths = { 0, 0 };
+        private readonly int[] previousDonLengths = { 0, 0 };
+        private readonly int[] previousKatLengths = { 0, 0 };
 
         private int sameTypeCount = 1;
 
         // TODO: make this smarter (dont initialise with "Don")
-        private bool previousIsKat = false;
+        private bool previousIsKat;
 
         protected override double StrainValueOf(DifficultyHitObject current)
         {

osu.Game.Rulesets.Taiko/Difficulty/Skills/SpeedInvariantRhythm.cs

@@ -14,13 +14,13 @@ namespace osu.Game.Rulesets.Taiko.Difficulty.Skills
         protected override double SkillMultiplier => 1;
         protected override double StrainDecayBase => 0;
         private const double strain_decay = 0.96;
-        private double currentStrain = 0.0;
+        private double currentStrain;
 
         private readonly List<TaikoDifficultyHitObject> ratioObjectHistory = new List<TaikoDifficultyHitObject>();
-        private int ratioHistoryLength = 0;
+        private int ratioHistoryLength;
         private const int ratio_history_max_length = 8;
 
-        private int rhythmLength = 0;
+        private int rhythmLength;
 
         // Penalty for repeated sequences of rhythm changes
         private double repititionPenalty(double timeSinceRepititionMS)

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

@@ -117,10 +117,11 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate)
         {
             List<TaikoDifficultyHitObject> taikoDifficultyHitObjects = new List<TaikoDifficultyHitObject>();
+            var rhythm = new TaikoDifficultyHitObjectRhythm();
 
             for (int i = 2; i < beatmap.HitObjects.Count; i++)
             {
-                taikoDifficultyHitObjects.Add(new TaikoDifficultyHitObject(beatmap.HitObjects[i], beatmap.HitObjects[i - 1], beatmap.HitObjects[i - 2], clockRate));
+                taikoDifficultyHitObjects.Add(new TaikoDifficultyHitObject(beatmap.HitObjects[i], beatmap.HitObjects[i - 1], beatmap.HitObjects[i - 2], clockRate, rhythm));
             }
 
             new StaminaCheeseDetector().FindCheese(taikoDifficultyHitObjects);