Turn difficulty & performance attributes into structs

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

@@ -19,9 +19,9 @@
         {
         }
 
-        protected override DifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
+        protected override IDifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
         {
-            return new DifficultyAttributes(mods, 0);
+            return new EmptyDifficultyAttributes();
         }
 
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();

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

@@ -19,9 +19,9 @@
         {
         }
 
-        protected override DifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
+        protected override IDifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
         {
-            return new DifficultyAttributes(mods, 0);
+            return new EmptyDifficultyAttributes();
         }
 
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();

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

@@ -19,9 +19,9 @@
         {
         }
 
-        protected override DifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
+        protected override IDifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
         {
-            return new DifficultyAttributes(mods, 0);
+            return new EmptyDifficultyAttributes();
         }
 
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();

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

@@ -19,9 +19,9 @@
         {
         }
 
-        protected override DifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
+        protected override IDifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
         {
-            return new DifficultyAttributes(mods, 0);
+            return new EmptyDifficultyAttributes();
         }
 
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();

osu.Game.Benchmarks/BenchmarkDifficultyCalculation.cs

@@ -0,0 +1,96 @@
+// Copyright (c) ppy Pty Ltd <[email protected]>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.IO;
+using BenchmarkDotNet.Attributes;
+using osu.Framework.IO.Stores;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.Formats;
+using osu.Game.IO;
+using osu.Game.IO.Archives;
+using osu.Game.Rulesets;
+using osu.Game.Rulesets.Catch;
+using osu.Game.Rulesets.Difficulty;
+using osu.Game.Rulesets.Mania;
+using osu.Game.Rulesets.Osu;
+using osu.Game.Rulesets.Taiko;
+using osu.Game.Scoring;
+using osu.Game.Tests.Resources;
+
+namespace osu.Game.Benchmarks
+{
+    public class BenchmarkDifficultyCalculation : BenchmarkTest
+    {
+        private FlatWorkingBeatmap beatmap = null!;
+
+        private IDifficultyAttributes osuAttributes = null!;
+        private IDifficultyAttributes taikoAttributes = null!;
+        private IDifficultyAttributes catchAttributes = null!;
+        private IDifficultyAttributes maniaAttributes = null!;
+
+        public override void SetUp()
+        {
+            using var resources = new DllResourceStore(typeof(TestResources).Assembly);
+            using var archive = resources.GetStream("Resources/Archives/241526 Soleily - Renatus.osz");
+            using var zipReader = new ZipArchiveReader(archive);
+
+            using var beatmapStream = new MemoryStream();
+            zipReader.GetStream("Soleily - Renatus (Gamu) [Insane].osu").CopyTo(beatmapStream);
+            beatmapStream.Seek(0, SeekOrigin.Begin);
+            var reader = new LineBufferedReader(beatmapStream);
+            var decoder = Decoder.GetDecoder<Beatmap>(reader);
+
+            beatmap = new FlatWorkingBeatmap(decoder.Decode(reader));
+
+            // Prepare difficulty attributes for an isolated performance calculation in every mode.
+            osuAttributes = DifficultyOsu();
+            taikoAttributes = DifficultyTaiko();
+            catchAttributes = DifficultyCatch();
+            maniaAttributes = DifficultyMania();
+        }
+
+        [Benchmark]
+        public IDifficultyAttributes DifficultyOsu() => new OsuRuleset().CreateDifficultyCalculator(beatmap).Calculate();
+
+        [Benchmark]
+        public IDifficultyAttributes DifficultyTaiko() => new TaikoRuleset().CreateDifficultyCalculator(beatmap).Calculate();
+
+        [Benchmark]
+        public IDifficultyAttributes DifficultyCatch() => new CatchRuleset().CreateDifficultyCalculator(beatmap).Calculate();
+
+        [Benchmark]
+        public IDifficultyAttributes DifficultyMania() => new ManiaRuleset().CreateDifficultyCalculator(beatmap).Calculate();
+
+        [Benchmark]
+        public void PerformanceOsu()
+        {
+            Ruleset ruleset = new OsuRuleset();
+            ScoreInfo score = new ScoreInfo(beatmap.BeatmapInfo, ruleset.RulesetInfo);
+            ruleset.CreatePerformanceCalculator()!.Calculate(score, osuAttributes);
+        }
+
+        [Benchmark]
+        public void PerformanceTaiko()
+        {
+            Ruleset ruleset = new TaikoRuleset();
+            ScoreInfo score = new ScoreInfo(beatmap.BeatmapInfo, ruleset.RulesetInfo);
+            ruleset.CreatePerformanceCalculator()!.Calculate(score, taikoAttributes);
+        }
+
+        [Benchmark]
+        public void PerformanceCatch()
+        {
+            Ruleset ruleset = new CatchRuleset();
+            ScoreInfo score = new ScoreInfo(beatmap.BeatmapInfo, ruleset.RulesetInfo);
+            ruleset.CreatePerformanceCalculator()!.Calculate(score, catchAttributes);
+        }
+
+        [Benchmark]
+        public void PerformanceMania()
+        {
+            Ruleset ruleset = new ManiaRuleset();
+            ScoreInfo score = new ScoreInfo(beatmap.BeatmapInfo, ruleset.RulesetInfo);
+            ruleset.CreatePerformanceCalculator()!.Calculate(score, maniaAttributes);
+        }
+    }
+}

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

@@ -8,8 +8,15 @@
 
 namespace osu.Game.Rulesets.Catch.Difficulty
 {
-    public class CatchDifficultyAttributes : DifficultyAttributes
+    [JsonObject(MemberSerialization.OptIn)]
+    public struct CatchDifficultyAttributes : IDifficultyAttributes
     {
+        /// <inheritdoc/>
+        public double StarRating { get; set; }
+
+        /// <inheritdoc/>
+        public int MaxCombo { get; set; }
+
         /// <summary>
         /// The perceived approach rate inclusive of rate-adjusting mods (DT/HT/etc).
         /// </summary>
@@ -19,22 +26,19 @@ public class CatchDifficultyAttributes : DifficultyAttributes
         [JsonProperty("approach_rate")]
         public double ApproachRate { get; set; }
 
-        public override IEnumerable<(int attributeId, object value)> ToDatabaseAttributes()
+        public IEnumerable<(int attributeId, object value)> ToDatabaseAttributes()
         {
-            foreach (var v in base.ToDatabaseAttributes())
-                yield return v;
-
+            yield return (IDifficultyAttributes.ATTRIB_ID_MAX_COMBO, MaxCombo);
             // Todo: osu!catch should not output star rating in the 'aim' attribute.
-            yield return (ATTRIB_ID_AIM, StarRating);
-            yield return (ATTRIB_ID_APPROACH_RATE, ApproachRate);
+            yield return (IDifficultyAttributes.ATTRIB_ID_AIM, StarRating);
+            yield return (IDifficultyAttributes.ATTRIB_ID_APPROACH_RATE, ApproachRate);
         }
 
-        public override void FromDatabaseAttributes(IReadOnlyDictionary<int, double> values, IBeatmapOnlineInfo onlineInfo)
+        public void FromDatabaseAttributes(IReadOnlyDictionary<int, double> values, IBeatmapOnlineInfo onlineInfo)
         {
-            base.FromDatabaseAttributes(values, onlineInfo);
-
-            StarRating = values[ATTRIB_ID_AIM];
-            ApproachRate = values[ATTRIB_ID_APPROACH_RATE];
+            MaxCombo = (int)values[IDifficultyAttributes.ATTRIB_ID_MAX_COMBO];
+            StarRating = values[IDifficultyAttributes.ATTRIB_ID_AIM];
+            ApproachRate = values[IDifficultyAttributes.ATTRIB_ID_APPROACH_RATE];
         }
     }
 }

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

@@ -30,18 +30,17 @@ public CatchDifficultyCalculator(IRulesetInfo ruleset, IWorkingBeatmap beatmap)
         {
         }
 
-        protected override DifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
+        protected override IDifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
         {
             if (beatmap.HitObjects.Count == 0)
-                return new CatchDifficultyAttributes { Mods = mods };
+                return new CatchDifficultyAttributes();
 
             // this is the same as osu!, so there's potential to share the implementation... maybe
             double preempt = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.ApproachRate, 1800, 1200, 450) / clockRate;
 
             CatchDifficultyAttributes attributes = new CatchDifficultyAttributes
             {
                 StarRating = Math.Sqrt(skills[0].DifficultyValue()) * difficulty_multiplier,
-                Mods = mods,
                 ApproachRate = preempt > 1200.0 ? -(preempt - 1800.0) / 120.0 : -(preempt - 1200.0) / 150.0 + 5.0,
                 MaxCombo = beatmap.GetMaxCombo(),
             };

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

@@ -1,11 +1,23 @@
 // Copyright (c) ppy Pty Ltd <[email protected]>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Collections.Generic;
+using Newtonsoft.Json;
 using osu.Game.Rulesets.Difficulty;
 
 namespace osu.Game.Rulesets.Catch.Difficulty
 {
-    public class CatchPerformanceAttributes : PerformanceAttributes
+    public struct CatchPerformanceAttributes : IPerformanceAttributes
     {
+        /// <summary>
+        /// Calculated score performance points.
+        /// </summary>
+        [JsonProperty("pp")]
+        public double Total { get; set; }
+
+        public IEnumerable<PerformanceDisplayAttribute> GetAttributesForDisplay()
+        {
+            yield return new PerformanceDisplayAttribute(nameof(Total), "Achieved PP", Total);
+        }
     }
 }

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

@@ -23,7 +23,7 @@ public CatchPerformanceCalculator()
         {
         }
 
-        protected override PerformanceAttributes CreatePerformanceAttributes(ScoreInfo score, DifficultyAttributes attributes)
+        protected override IPerformanceAttributes CreatePerformanceAttributes(ScoreInfo score, IDifficultyAttributes attributes)
         {
             var catchAttributes = (CatchDifficultyAttributes)attributes;
 

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

@@ -8,8 +8,15 @@
 
 namespace osu.Game.Rulesets.Mania.Difficulty
 {
-    public class ManiaDifficultyAttributes : DifficultyAttributes
+    [JsonObject(MemberSerialization.OptIn)]
+    public struct ManiaDifficultyAttributes : IDifficultyAttributes
     {
+        /// <inheritdoc/>
+        public double StarRating { get; set; }
+
+        /// <inheritdoc/>
+        public int MaxCombo { get; set; }
+
         /// <summary>
         /// The hit window for a GREAT hit inclusive of rate-adjusting mods (DT/HT/etc).
         /// </summary>
@@ -19,21 +26,18 @@ public class ManiaDifficultyAttributes : DifficultyAttributes
         [JsonProperty("great_hit_window")]
         public double GreatHitWindow { get; set; }
 
-        public override IEnumerable<(int attributeId, object value)> ToDatabaseAttributes()
+        public IEnumerable<(int attributeId, object value)> ToDatabaseAttributes()
         {
-            foreach (var v in base.ToDatabaseAttributes())
-                yield return v;
-
-            yield return (ATTRIB_ID_DIFFICULTY, StarRating);
-            yield return (ATTRIB_ID_GREAT_HIT_WINDOW, GreatHitWindow);
+            yield return (IDifficultyAttributes.ATTRIB_ID_MAX_COMBO, MaxCombo);
+            yield return (IDifficultyAttributes.ATTRIB_ID_DIFFICULTY, StarRating);
+            yield return (IDifficultyAttributes.ATTRIB_ID_GREAT_HIT_WINDOW, GreatHitWindow);
         }
 
-        public override void FromDatabaseAttributes(IReadOnlyDictionary<int, double> values, IBeatmapOnlineInfo onlineInfo)
+        public void FromDatabaseAttributes(IReadOnlyDictionary<int, double> values, IBeatmapOnlineInfo onlineInfo)
         {
-            base.FromDatabaseAttributes(values, onlineInfo);
-
-            StarRating = values[ATTRIB_ID_DIFFICULTY];
-            GreatHitWindow = values[ATTRIB_ID_GREAT_HIT_WINDOW];
+            MaxCombo = (int)values[IDifficultyAttributes.ATTRIB_ID_MAX_COMBO];
+            StarRating = values[IDifficultyAttributes.ATTRIB_ID_DIFFICULTY];
+            GreatHitWindow = values[IDifficultyAttributes.ATTRIB_ID_GREAT_HIT_WINDOW];
         }
     }
 }

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

@@ -38,18 +38,17 @@ public ManiaDifficultyCalculator(IRulesetInfo ruleset, IWorkingBeatmap beatmap)
             originalOverallDifficulty = beatmap.BeatmapInfo.Difficulty.OverallDifficulty;
         }
 
-        protected override DifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
+        protected override IDifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
         {
             if (beatmap.HitObjects.Count == 0)
-                return new ManiaDifficultyAttributes { Mods = mods };
+                return new ManiaDifficultyAttributes();
 
             HitWindows hitWindows = new ManiaHitWindows();
             hitWindows.SetDifficulty(beatmap.Difficulty.OverallDifficulty);
 
             ManiaDifficultyAttributes attributes = new ManiaDifficultyAttributes
             {
                 StarRating = skills[0].DifficultyValue() * difficulty_multiplier,
-                Mods = mods,
                 // In osu-stable mania, rate-adjustment mods don't affect the hit window.
                 // This is done the way it is to introduce fractional differences in order to match osu-stable for the time being.
                 GreatHitWindow = Math.Ceiling((int)(getHitWindow300(mods) * clockRate) / clockRate),

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

@@ -7,16 +7,20 @@
 
 namespace osu.Game.Rulesets.Mania.Difficulty
 {
-    public class ManiaPerformanceAttributes : PerformanceAttributes
+    public struct ManiaPerformanceAttributes : IPerformanceAttributes
     {
+        /// <summary>
+        /// Calculated score performance points.
+        /// </summary>
+        [JsonProperty("pp")]
+        public double Total { get; set; }
+
         [JsonProperty("difficulty")]
         public double Difficulty { get; set; }
 
-        public override IEnumerable<PerformanceDisplayAttribute> GetAttributesForDisplay()
+        public IEnumerable<PerformanceDisplayAttribute> GetAttributesForDisplay()
         {
-            foreach (var attribute in base.GetAttributesForDisplay())
-                yield return attribute;
-
+            yield return new PerformanceDisplayAttribute(nameof(Total), "Achieved PP", Total);
             yield return new PerformanceDisplayAttribute(nameof(Difficulty), "Difficulty", Difficulty);
         }
     }

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

@@ -26,7 +26,7 @@ public ManiaPerformanceCalculator()
         {
         }
 
-        protected override PerformanceAttributes CreatePerformanceAttributes(ScoreInfo score, DifficultyAttributes attributes)
+        protected override IPerformanceAttributes CreatePerformanceAttributes(ScoreInfo score, IDifficultyAttributes attributes)
         {
             var maniaAttributes = (ManiaDifficultyAttributes)attributes;
 

osu.Game.Rulesets.Osu.Tests/OsuDifficultyCalculatorTest.cs

@@ -34,6 +34,18 @@ public void TestClockRateAdjusted(double expectedStarRating, int expectedMaxComb
         public void TestClassicMod(double expectedStarRating, int expectedMaxCombo, string name)
             => Test(expectedStarRating, expectedMaxCombo, name, new OsuModClassic());
 
+        [Test]
+        public void TestFlashlightDifficultyNullability()
+        {
+            IWorkingBeatmap beatmap = GetBeatmap("diffcalc-test");
+
+            OsuDifficultyAttributes attributes = (OsuDifficultyAttributes)CreateDifficultyCalculator(beatmap).Calculate();
+            Assert.IsNull(attributes.FlashlightDifficulty);
+
+            attributes = (OsuDifficultyAttributes)CreateDifficultyCalculator(GetBeatmap("diffcalc-test")).Calculate([new OsuModFlashlight()]);
+            Assert.IsNotNull(attributes.FlashlightDifficulty);
+        }
+
         protected override DifficultyCalculator CreateDifficultyCalculator(IWorkingBeatmap beatmap) => new OsuDifficultyCalculator(new OsuRuleset().RulesetInfo, beatmap);
 
         protected override Ruleset CreateRuleset() => new OsuRuleset();