LTCA save me

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

@@ -1,33 +1,51 @@
 // 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.Difficulty.Skills;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Taiko.Difficulty.Evaluators;
+using osu.Game.Rulesets.Taiko.Difficulty.Preprocessing;
 
 namespace osu.Game.Rulesets.Taiko.Difficulty.Skills
 {
     /// <summary>
     /// Calculates the stamina coefficient of taiko difficulty.
     /// </summary>
-    public class Stamina : StrainDecaySkill
+    public class Stamina : StrainSkill
     {
-        protected override double SkillMultiplier => 1.1;
-        protected override double StrainDecayBase => 0.4;
+        private double skillMultiplier => 1.1;
+        private double strainDecayBase => 0.4;
+
+        private bool onlyMono;
+
+        private double currentStrain;
 
         /// <summary>
         /// Creates a <see cref="Stamina"/> skill.
         /// </summary>
         /// <param name="mods">Mods for use in skill calculations.</param>
-        public Stamina(Mod[] mods)
+        /// <param name="onlyMono">I hate strangeprogram</param>
+        public Stamina(Mod[] mods, bool onlyMono)
             : base(mods)
         {
+            this.onlyMono = onlyMono;
         }
 
-        protected override double StrainValueOf(DifficultyHitObject current)
+        private double strainDecay(double ms) => Math.Pow(strainDecayBase, ms / 1000);
+
+        protected override double StrainValueAt(DifficultyHitObject current)
         {
-            return StaminaEvaluator.EvaluateDifficultyOf(current);
+            currentStrain *= strainDecay(current.DeltaTime);
+            currentStrain += StaminaEvaluator.EvaluateDifficultyOf(current) * skillMultiplier;
+
+            if (onlyMono)
+                return ((TaikoDifficultyHitObject)current).Colour.MonoStreak?.RunLength >= 16 ? currentStrain : 0;
+
+            return currentStrain;
         }
+
+        protected override double CalculateInitialStrain(double time, DifficultyHitObject current) => onlyMono ? 0 : currentStrain * strainDecay(time - current.Previous(0).StartTime);
     }
 }

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

@@ -16,6 +16,12 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
         [JsonProperty("stamina_difficulty")]
         public double StaminaDifficulty { get; set; }
 
+        /// <summary>
+        /// The ratio of stamina difficulty from mono-color streams to total stamina difficulty.
+        /// </summary>
+        [JsonProperty("mono_stamina_factor")]
+        public double MonoStaminaFactor { get; set; }
+
         /// <summary>
         /// The difficulty corresponding to the rhythm skill.
         /// </summary>

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

@@ -38,7 +38,8 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
             {
                 new Rhythm(mods),
                 new Colour(mods),
-                new Stamina(mods)
+                new Stamina(mods, false),
+                new Stamina(mods, true)
             };
         }
 
@@ -79,10 +80,14 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
             Colour colour = (Colour)skills.First(x => x is Colour);
             Rhythm rhythm = (Rhythm)skills.First(x => x is Rhythm);
             Stamina stamina = (Stamina)skills.First(x => x is Stamina);
+            Stamina staminaMonos = (Stamina)skills.Last(x => x is Stamina);
 
             double colourRating = colour.DifficultyValue() * colour_skill_multiplier;
             double rhythmRating = rhythm.DifficultyValue() * rhythm_skill_multiplier;
             double staminaRating = stamina.DifficultyValue() * stamina_skill_multiplier;
+            double monoStaminaRating = staminaMonos.DifficultyValue() * stamina_skill_multiplier;
+
+            double monoStaminaFactor = Math.Pow(monoStaminaRating / staminaRating, 5);
 
             double combinedRating = combinedDifficultyValue(rhythm, colour, stamina);
             double starRating = rescale(combinedRating * 1.4);
@@ -95,6 +100,7 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
                 StarRating = starRating,
                 Mods = mods,
                 StaminaDifficulty = staminaRating,
+                MonoStaminaFactor = monoStaminaFactor,
                 RhythmDifficulty = rhythmRating,
                 ColourDifficulty = colourRating,
                 PeakDifficulty = combinedRating,

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

@@ -95,7 +95,11 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
             if (estimatedUnstableRate == null)
                 return 0;
 
-            return difficultyValue * Math.Pow(SpecialFunctions.Erf(400 / (Math.Sqrt(2) * estimatedUnstableRate.Value)), 2.0);
+            // Scale accuracy more harshly on nearly-completely mono speed maps.
+            double accScalingExponent = 2 + attributes.MonoStaminaFactor;
+            double accScalingShift = 300 - 100 * attributes.MonoStaminaFactor;
+
+            return difficultyValue * Math.Pow(SpecialFunctions.Erf(accScalingShift / (Math.Sqrt(2) * estimatedUnstableRate.Value)), accScalingExponent);
         }
 
         private double computeAccuracyValue(ScoreInfo score, TaikoDifficultyAttributes attributes, bool isConvert)