Encapsulate common HP logic from osu and catch HP calculations

osu.Game.Rulesets.Catch/Scoring/CatchHealthProcessor.cs

@@ -1,138 +1,27 @@
 // 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.Beatmaps;
 using osu.Game.Rulesets.Catch.Objects;
-using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Scoring;
 
 namespace osu.Game.Rulesets.Catch.Scoring
 {
-    public partial class CatchHealthProcessor : DrainingHealthProcessor
+    public partial class CatchHealthProcessor : LegacyDrainingHealthProcessor
     {
-        public Action<string>? OnIterationFail;
-        public Action<string>? OnIterationSuccess;
-
-        private double lowestHpEver;
-        private double lowestHpEnd;
-        private double hpRecoveryAvailable;
-        private double hpMultiplierNormal;
-
         public CatchHealthProcessor(double drainStartTime)
             : base(drainStartTime)
         {
         }
 
-        public override void ApplyBeatmap(IBeatmap beatmap)
+        protected override IEnumerable<HitObject> EnumerateTopLevelHitObjects() => EnumerateHitObjects(Beatmap).Where(h => h is Fruit || h is Droplet || h is Banana);
-        {
-            lowestHpEver = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.DrainRate, 0.975, 0.8, 0.3);
-            lowestHpEnd = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.DrainRate, 0.99, 0.9, 0.4);
-            hpRecoveryAvailable = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.DrainRate, 0.04, 0.02, 0);
 
-            base.ApplyBeatmap(beatmap);
+        protected override IEnumerable<HitObject> EnumerateNestedHitObjects(HitObject hitObject) => Enumerable.Empty<HitObject>();
-        }
 
-        protected override void Reset(bool storeResults)
+        protected override double GetHealthIncreaseFor(HitObject hitObject, HitResult result)
-        {
-            hpMultiplierNormal = 1;
-            base.Reset(storeResults);
-        }
-
-        protected override double ComputeDrainRate()
-        {
-            double testDrop = 0.00025;
-            double currentHp;
-            double currentHpUncapped;
-
-            while (true)
-            {
-                currentHp = 1;
-                currentHpUncapped = 1;
-
-                double lowestHp = currentHp;
-                double lastTime = DrainStartTime;
-                int currentBreak = 0;
-                bool fail = false;
-
-                List<HitObject> allObjects = EnumerateHitObjects(Beatmap).Where(h => h is Fruit || h is Droplet || h is Banana).ToList();
-
-                for (int i = 0; i < allObjects.Count; i++)
-                {
-                    HitObject h = allObjects[i];
-
-                    while (currentBreak < Beatmap.Breaks.Count && Beatmap.Breaks[currentBreak].EndTime <= h.StartTime)
-                    {
-                        // If two hitobjects are separated by a break period, there is no drain for the full duration between the hitobjects.
-                        // This differs from legacy (version < 8) beatmaps which continue draining until the break section is entered,
-                        // but this shouldn't have a noticeable impact in practice.
-                        lastTime = h.StartTime;
-                        currentBreak++;
-                    }
-
-                    reduceHp(testDrop * (h.StartTime - lastTime));
-
-                    lastTime = h.GetEndTime();
-
-                    if (currentHp < lowestHp)
-                        lowestHp = currentHp;
-
-                    if (currentHp <= lowestHpEver)
-                    {
-                        fail = true;
-                        testDrop *= 0.96;
-                        OnIterationFail?.Invoke($"FAILED drop {testDrop}: hp too low ({currentHp} < {lowestHpEver})");
-                        break;
-                    }
-
-                    increaseHp(h);
-                }
-
-                if (!fail && currentHp < lowestHpEnd)
-                {
-                    fail = true;
-                    testDrop *= 0.94;
-                    hpMultiplierNormal *= 1.01;
-                    OnIterationFail?.Invoke($"FAILED drop {testDrop}: end hp too low ({currentHp} < {lowestHpEnd})");
-                }
-
-                double recovery = (currentHpUncapped - 1) / allObjects.Count;
-
-                if (!fail && recovery < hpRecoveryAvailable)
-                {
-                    fail = true;
-                    testDrop *= 0.96;
-                    hpMultiplierNormal *= 1.01;
-                    OnIterationFail?.Invoke($"FAILED drop {testDrop}: recovery too low ({recovery} < {hpRecoveryAvailable})");
-                }
-
-                if (!fail)
-                {
-                    OnIterationSuccess?.Invoke($"PASSED drop {testDrop}");
-                    return testDrop;
-                }
-            }
-
-            void reduceHp(double amount)
-            {
-                currentHpUncapped = Math.Max(0, currentHpUncapped - amount);
-                currentHp = Math.Max(0, currentHp - amount);
-            }
-
-            void increaseHp(HitObject hitObject)
-            {
-                double amount = healthIncreaseFor(hitObject.CreateJudgement().MaxResult);
-                currentHpUncapped += amount;
-                currentHp = Math.Max(0, Math.Min(1, currentHp + amount));
-            }
-        }
-
-        protected override double GetHealthIncreaseFor(JudgementResult result) => healthIncreaseFor(result.Type);
-
-        private double healthIncreaseFor(HitResult result)
         {
             double increase = 0;
 
@@ -162,7 +51,7 @@ namespace osu.Game.Rulesets.Catch.Scoring
                     break;
             }
 
-            return hpMultiplierNormal * increase;
+            return HpMultiplierNormal * increase;
         }
     }
 }

osu.Game.Rulesets.Osu/Scoring/OsuHealthProcessor.cs

@@ -1,166 +1,43 @@
 // 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.Beatmaps;
-using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Rulesets.Scoring;
 
 namespace osu.Game.Rulesets.Osu.Scoring
 {
-    public partial class OsuHealthProcessor : DrainingHealthProcessor
+    public partial class OsuHealthProcessor : LegacyDrainingHealthProcessor
     {
-        public Action<string>? OnIterationFail;
-        public Action<string>? OnIterationSuccess;
-
-        private double lowestHpEver;
-        private double lowestHpEnd;
-        private double hpRecoveryAvailable;
-        private double hpMultiplierNormal;
-
         public OsuHealthProcessor(double drainStartTime)
             : base(drainStartTime)
         {
         }
 
-        public override void ApplyBeatmap(IBeatmap beatmap)
+        protected override IEnumerable<HitObject> EnumerateTopLevelHitObjects() => Beatmap.HitObjects;
+
+        protected override IEnumerable<HitObject> EnumerateNestedHitObjects(HitObject hitObject)
         {
-            lowestHpEver = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.DrainRate, 0.975, 0.8, 0.3);
+            switch (hitObject)
-            lowestHpEnd = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.DrainRate, 0.99, 0.9, 0.4);
-            hpRecoveryAvailable = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.DrainRate, 0.04, 0.02, 0);
-
-            base.ApplyBeatmap(beatmap);
-        }
-
-        protected override void Reset(bool storeResults)
-        {
-            hpMultiplierNormal = 1;
-            base.Reset(storeResults);
-        }
-
-        protected override double ComputeDrainRate()
-        {
-            double testDrop = 0.00025;
-            double currentHp;
-            double currentHpUncapped;
-
-            while (true)
-            {
-                currentHp = 1;
-                currentHpUncapped = 1;
-
-                double lowestHp = currentHp;
-                double lastTime = DrainStartTime;
-                int currentBreak = 0;
-                bool fail = false;
-
-                for (int i = 0; i < Beatmap.HitObjects.Count; i++)
-                {
-                    HitObject h = Beatmap.HitObjects[i];
-
-                    while (currentBreak < Beatmap.Breaks.Count && Beatmap.Breaks[currentBreak].EndTime <= h.StartTime)
-                    {
-                        // If two hitobjects are separated by a break period, there is no drain for the full duration between the hitobjects.
-                        // This differs from legacy (version < 8) beatmaps which continue draining until the break section is entered,
-                        // but this shouldn't have a noticeable impact in practice.
-                        lastTime = h.StartTime;
-                        currentBreak++;
-                    }
-
-                    reduceHp(testDrop * (h.StartTime - lastTime));
-
-                    lastTime = h.GetEndTime();
-
-                    if (currentHp < lowestHp)
-                        lowestHp = currentHp;
-
-                    if (currentHp <= lowestHpEver)
-                    {
-                        fail = true;
-                        testDrop *= 0.96;
-                        OnIterationFail?.Invoke($"FAILED drop {testDrop}: hp too low ({currentHp} < {lowestHpEver})");
-                        break;
-                    }
-
-                    double hpReduction = testDrop * (h.GetEndTime() - h.StartTime);
-                    double hpOverkill = Math.Max(0, hpReduction - currentHp);
-                    reduceHp(hpReduction);
-
-                    switch (h)
             {
                 case Slider slider:
-                        {
                     foreach (var nested in slider.NestedHitObjects)
-                                increaseHp(nested);
+                        yield return nested;
+
                     break;
-                        }
 
                 case Spinner spinner:
-                        {
                     foreach (var nested in spinner.NestedHitObjects.Where(t => t is not SpinnerBonusTick))
-                                increaseHp(nested);
+                        yield return nested;
+
                     break;
             }
         }
 
-                    // Note: Because HP is capped during the above increases, long sliders (with many ticks) or spinners
+        protected override double GetHealthIncreaseFor(HitObject hitObject, HitResult result)
-                    // will appear to overkill at lower drain levels than they should. However, it is also not correct to simply use the uncapped version.
-                    if (hpOverkill > 0 && currentHp - hpOverkill <= lowestHpEver)
-                    {
-                        fail = true;
-                        testDrop *= 0.96;
-                        OnIterationFail?.Invoke($"FAILED drop {testDrop}: overkill ({currentHp} - {hpOverkill} <= {lowestHpEver})");
-                        break;
-                    }
-
-                    increaseHp(h);
-                }
-
-                if (!fail && currentHp < lowestHpEnd)
-                {
-                    fail = true;
-                    testDrop *= 0.94;
-                    hpMultiplierNormal *= 1.01;
-                    OnIterationFail?.Invoke($"FAILED drop {testDrop}: end hp too low ({currentHp} < {lowestHpEnd})");
-                }
-
-                double recovery = (currentHpUncapped - 1) / Beatmap.HitObjects.Count;
-
-                if (!fail && recovery < hpRecoveryAvailable)
-                {
-                    fail = true;
-                    testDrop *= 0.96;
-                    hpMultiplierNormal *= 1.01;
-                    OnIterationFail?.Invoke($"FAILED drop {testDrop}: recovery too low ({recovery} < {hpRecoveryAvailable})");
-                }
-
-                if (!fail)
-                {
-                    OnIterationSuccess?.Invoke($"PASSED drop {testDrop}");
-                    return testDrop;
-                }
-            }
-
-            void reduceHp(double amount)
-            {
-                currentHpUncapped = Math.Max(0, currentHpUncapped - amount);
-                currentHp = Math.Max(0, currentHp - amount);
-            }
-
-            void increaseHp(HitObject hitObject)
-            {
-                double amount = healthIncreaseFor(hitObject, hitObject.CreateJudgement().MaxResult);
-                currentHpUncapped += amount;
-                currentHp = Math.Max(0, Math.Min(1, currentHp + amount));
-            }
-        }
-
-        protected override double GetHealthIncreaseFor(JudgementResult result) => healthIncreaseFor(result.HitObject, result.Type);
-
-        private double healthIncreaseFor(HitObject hitObject, HitResult result)
         {
             double increase = 0;
 
@@ -206,7 +83,7 @@ namespace osu.Game.Rulesets.Osu.Scoring
                     break;
             }
 
-            return hpMultiplierNormal * increase;
+            return HpMultiplierNormal * increase;
         }
     }
 }

osu.Game/Rulesets/Scoring/LegacyDrainingHealthProcessor.cs

@@ -0,0 +1,158 @@
+// 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 osu.Game.Beatmaps;
+using osu.Game.Rulesets.Judgements;
+using osu.Game.Rulesets.Objects;
+
+namespace osu.Game.Rulesets.Scoring
+{
+    /// <summary>
+    /// A <see cref="DrainingHealthProcessor"/> that matches legacy drain rate calculations as best as possible.
+    /// </summary>
+    public abstract partial class LegacyDrainingHealthProcessor : DrainingHealthProcessor
+    {
+        public Action<string>? OnIterationFail;
+        public Action<string>? OnIterationSuccess;
+
+        protected double HpMultiplierNormal { get; private set; }
+
+        private double lowestHpEver;
+        private double lowestHpEnd;
+        private double hpRecoveryAvailable;
+
+        protected LegacyDrainingHealthProcessor(double drainStartTime)
+            : base(drainStartTime)
+        {
+        }
+
+        public override void ApplyBeatmap(IBeatmap beatmap)
+        {
+            lowestHpEver = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.DrainRate, 0.975, 0.8, 0.3);
+            lowestHpEnd = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.DrainRate, 0.99, 0.9, 0.4);
+            hpRecoveryAvailable = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.DrainRate, 0.04, 0.02, 0);
+
+            base.ApplyBeatmap(beatmap);
+        }
+
+        protected override void Reset(bool storeResults)
+        {
+            HpMultiplierNormal = 1;
+            base.Reset(storeResults);
+        }
+
+        protected override double ComputeDrainRate()
+        {
+            double testDrop = 0.00025;
+            double currentHp;
+            double currentHpUncapped;
+
+            while (true)
+            {
+                currentHp = 1;
+                currentHpUncapped = 1;
+
+                double lowestHp = currentHp;
+                double lastTime = DrainStartTime;
+                int currentBreak = 0;
+                bool fail = false;
+                int topLevelObjectCount = 0;
+
+                foreach (var h in EnumerateTopLevelHitObjects())
+                {
+                    topLevelObjectCount++;
+
+                    while (currentBreak < Beatmap.Breaks.Count && Beatmap.Breaks[currentBreak].EndTime <= h.StartTime)
+                    {
+                        // If two hitobjects are separated by a break period, there is no drain for the full duration between the hitobjects.
+                        // This differs from legacy (version < 8) beatmaps which continue draining until the break section is entered,
+                        // but this shouldn't have a noticeable impact in practice.
+                        lastTime = h.StartTime;
+                        currentBreak++;
+                    }
+
+                    reduceHp(testDrop * (h.StartTime - lastTime));
+
+                    lastTime = h.GetEndTime();
+
+                    if (currentHp < lowestHp)
+                        lowestHp = currentHp;
+
+                    if (currentHp <= lowestHpEver)
+                    {
+                        fail = true;
+                        testDrop *= 0.96;
+                        OnIterationFail?.Invoke($"FAILED drop {testDrop}: hp too low ({currentHp} < {lowestHpEver})");
+                        break;
+                    }
+
+                    double hpReduction = testDrop * (h.GetEndTime() - h.StartTime);
+                    double hpOverkill = Math.Max(0, hpReduction - currentHp);
+                    reduceHp(hpReduction);
+
+                    foreach (var nested in EnumerateNestedHitObjects(h))
+                        increaseHp(nested);
+
+                    // Note: Because HP is capped during the above increases, long sliders (with many ticks) or spinners
+                    // will appear to overkill at lower drain levels than they should. However, it is also not correct to simply use the uncapped version.
+                    if (hpOverkill > 0 && currentHp - hpOverkill <= lowestHpEver)
+                    {
+                        fail = true;
+                        testDrop *= 0.96;
+                        OnIterationFail?.Invoke($"FAILED drop {testDrop}: overkill ({currentHp} - {hpOverkill} <= {lowestHpEver})");
+                        break;
+                    }
+
+                    increaseHp(h);
+                }
+
+                if (!fail && currentHp < lowestHpEnd)
+                {
+                    fail = true;
+                    testDrop *= 0.94;
+                    HpMultiplierNormal *= 1.01;
+                    OnIterationFail?.Invoke($"FAILED drop {testDrop}: end hp too low ({currentHp} < {lowestHpEnd})");
+                }
+
+                double recovery = (currentHpUncapped - 1) / Math.Max(1, topLevelObjectCount);
+
+                if (!fail && recovery < hpRecoveryAvailable)
+                {
+                    fail = true;
+                    testDrop *= 0.96;
+                    HpMultiplierNormal *= 1.01;
+                    OnIterationFail?.Invoke($"FAILED drop {testDrop}: recovery too low ({recovery} < {hpRecoveryAvailable})");
+                }
+
+                if (!fail)
+                {
+                    OnIterationSuccess?.Invoke($"PASSED drop {testDrop}");
+                    return testDrop;
+                }
+            }
+
+            void reduceHp(double amount)
+            {
+                currentHpUncapped = Math.Max(0, currentHpUncapped - amount);
+                currentHp = Math.Max(0, currentHp - amount);
+            }
+
+            void increaseHp(HitObject hitObject)
+            {
+                double amount = GetHealthIncreaseFor(hitObject, hitObject.CreateJudgement().MaxResult);
+                currentHpUncapped += amount;
+                currentHp = Math.Max(0, Math.Min(1, currentHp + amount));
+            }
+        }
+
+        protected sealed override double GetHealthIncreaseFor(JudgementResult result) => GetHealthIncreaseFor(result.HitObject, result.Type);
+
+        protected abstract IEnumerable<HitObject> EnumerateTopLevelHitObjects();
+
+        protected abstract IEnumerable<HitObject> EnumerateNestedHitObjects(HitObject hitObject);
+
+        protected abstract double GetHealthIncreaseFor(HitObject hitObject, HitResult result);
+    }
+}