Merge pull request #11857 from Syriiin/diffcalc/refactor/catch-clockrate-effects

Refactor catch Movement skill to not require explicit clockrate usage

Templates/Rulesets/ruleset-empty/osu.Game.Rulesets.EmptyFreeform/EmptyFreeformDifficultyCalculator.cs

@@ -25,6 +25,6 @@ namespace osu.Game.Rulesets.EmptyFreeform
 
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();
 
-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods) => new Skill[0];
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[0];
     }
 }

Templates/Rulesets/ruleset-example/osu.Game.Rulesets.Pippidon/PippidonDifficultyCalculator.cs

@@ -25,6 +25,6 @@ namespace osu.Game.Rulesets.Pippidon
 
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();
 
-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods) => new Skill[0];
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[0];
     }
 }

Templates/Rulesets/ruleset-scrolling-empty/osu.Game.Rulesets.EmptyScrolling/EmptyScrollingDifficultyCalculator.cs

@@ -25,6 +25,6 @@ namespace osu.Game.Rulesets.EmptyScrolling
 
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();
 
-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods) => new Skill[0];
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[0];
     }
 }

Templates/Rulesets/ruleset-scrolling-example/osu.Game.Rulesets.Pippidon/PippidonDifficultyCalculator.cs

@@ -25,6 +25,6 @@ namespace osu.Game.Rulesets.Pippidon
 
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();
 
-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods) => new Skill[0];
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[0];
     }
 }

osu.Game.Rulesets.Catch/Difficulty/CatchDifficultyCalculator.cs

@@ -67,7 +67,7 @@ namespace osu.Game.Rulesets.Catch.Difficulty
             }
         }
 
-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods)
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate)
         {
             halfCatcherWidth = Catcher.CalculateCatchWidth(beatmap.BeatmapInfo.BaseDifficulty) * 0.5f;
 
@@ -76,7 +76,7 @@ namespace osu.Game.Rulesets.Catch.Difficulty
 
             return new Skill[]
             {
-                new Movement(mods, halfCatcherWidth),
+                new Movement(mods, halfCatcherWidth, clockRate),
             };
         }
 

osu.Game.Rulesets.Catch/Difficulty/Preprocessing/CatchDifficultyHitObject.cs

@@ -24,8 +24,6 @@ namespace osu.Game.Rulesets.Catch.Difficulty.Preprocessing
         /// </summary>
         public readonly double StrainTime;
 
-        public readonly double ClockRate;
-
         public CatchDifficultyHitObject(HitObject hitObject, HitObject lastObject, double clockRate, float halfCatcherWidth)
             : base(hitObject, lastObject, clockRate)
         {
@@ -37,7 +35,6 @@ namespace osu.Game.Rulesets.Catch.Difficulty.Preprocessing
 
             // Every strain interval is hard capped at the equivalent of 375 BPM streaming speed as a safety measure
             StrainTime = Math.Max(40, DeltaTime);
-            ClockRate = clockRate;
         }
     }
 }

osu.Game.Rulesets.Catch/Difficulty/Skills/Movement.cs

@@ -28,10 +28,21 @@ namespace osu.Game.Rulesets.Catch.Difficulty.Skills
         private float lastDistanceMoved;
         private double lastStrainTime;
 
-        public Movement(Mod[] mods, float halfCatcherWidth)
+        /// <summary>
+        /// The speed multiplier applied to the player's catcher.
+        /// </summary>
+        private readonly double catcherSpeedMultiplier;
+
+        public Movement(Mod[] mods, float halfCatcherWidth, double clockRate)
             : base(mods)
         {
             HalfCatcherWidth = halfCatcherWidth;
+
+            // In catch, clockrate adjustments do not only affect the timings of hitobjects,
+            // but also the speed of the player's catcher, which has an impact on difficulty
+            // TODO: Support variable clockrates caused by mods such as ModTimeRamp
+            //  (perhaps by using IApplicableToRate within the CatchDifficultyHitObject constructor to set a catcher speed for each object before processing)
+            catcherSpeedMultiplier = clockRate;
         }
 
         protected override double StrainValueOf(DifficultyHitObject current)
@@ -48,7 +59,7 @@ namespace osu.Game.Rulesets.Catch.Difficulty.Skills
 
             float distanceMoved = playerPosition - lastPlayerPosition.Value;
 
-            double weightedStrainTime = catchCurrent.StrainTime + 13 + (3 / catchCurrent.ClockRate);
+            double weightedStrainTime = catchCurrent.StrainTime + 13 + (3 / catcherSpeedMultiplier);
 
             double distanceAddition = (Math.Pow(Math.Abs(distanceMoved), 1.3) / 510);
             double sqrtStrain = Math.Sqrt(weightedStrainTime);
@@ -81,7 +92,7 @@ namespace osu.Game.Rulesets.Catch.Difficulty.Skills
                     playerPosition = catchCurrent.NormalizedPosition;
                 }
 
-                distanceAddition *= 1.0 + edgeDashBonus * ((20 - catchCurrent.LastObject.DistanceToHyperDash) / 20) * Math.Pow((Math.Min(catchCurrent.StrainTime * catchCurrent.ClockRate, 265) / 265), 1.5); // Edge Dashes are easier at lower ms values
+                distanceAddition *= 1.0 + edgeDashBonus * ((20 - catchCurrent.LastObject.DistanceToHyperDash) / 20) * Math.Pow((Math.Min(catchCurrent.StrainTime * catcherSpeedMultiplier, 265) / 265), 1.5); // Edge Dashes are easier at lower ms values
             }
 
             lastPlayerPosition = playerPosition;

osu.Game.Rulesets.Mania/Difficulty/ManiaDifficultyCalculator.cs

@@ -68,7 +68,7 @@ namespace osu.Game.Rulesets.Mania.Difficulty
         // Sorting is done in CreateDifficultyHitObjects, since the full list of hitobjects is required.
         protected override IEnumerable<DifficultyHitObject> SortObjects(IEnumerable<DifficultyHitObject> input) => input;
 
-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods) => new Skill[]
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[]
         {
             new Strain(mods, ((ManiaBeatmap)beatmap).TotalColumns)
         };

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

@@ -79,7 +79,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty
             }
         }
 
-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods) => new Skill[]
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[]
         {
             new Aim(mods),
             new Speed(mods)

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

@@ -29,7 +29,7 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
         {
         }
 
-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods) => new Skill[]
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[]
         {
             new Colour(mods),
             new Rhythm(mods),

osu.Game.Tests/NonVisual/DifficultyAdjustmentModCombinationsTest.cs

@@ -217,7 +217,7 @@ namespace osu.Game.Tests.NonVisual
                 throw new NotImplementedException();
             }
 
-            protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods)
+            protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate)
             {
                 throw new NotImplementedException();
             }

osu.Game/Rulesets/Difficulty/DifficultyCalculator.cs

@@ -59,7 +59,7 @@ namespace osu.Game.Rulesets.Difficulty
 
         private DifficultyAttributes calculate(IBeatmap beatmap, Mod[] mods, double clockRate)
         {
-            var skills = CreateSkills(beatmap, mods);
+            var skills = CreateSkills(beatmap, mods, clockRate);
 
             if (!beatmap.HitObjects.Any())
                 return CreateDifficultyAttributes(beatmap, mods, skills, clockRate);
@@ -180,7 +180,8 @@ namespace osu.Game.Rulesets.Difficulty
         /// </summary>
         /// <param name="beatmap">The <see cref="IBeatmap"/> whose difficulty will be calculated.</param>
         /// <param name="mods">Mods to calculate difficulty with.</param>
+        /// <param name="clockRate">Clockrate to calculate difficulty with.</param>
         /// <returns>The <see cref="Skill"/>s.</returns>
-        protected abstract Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods);
+        protected abstract Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate);
     }
 }