Merge pull request #24072 from smoogipoo/diffcalc-total-scorev1

Add difficulty attributes to facilitate conversion from legacy score, and convert existing scores

osu.Game.Rulesets.Catch/CatchRuleset.cs

@@ -202,6 +202,8 @@ namespace osu.Game.Rulesets.Catch
 
         public int LegacyID => 2;
 
+        public ILegacyScoreSimulator CreateLegacyScoreSimulator() => new CatchLegacyScoreSimulator();
+
         public override IConvertibleReplayFrame CreateConvertibleReplayFrame() => new CatchReplayFrame();
 
         public override HitObjectComposer CreateHitObjectComposer() => new CatchHitObjectComposer(this);

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

@@ -27,7 +27,6 @@ namespace osu.Game.Rulesets.Catch.Difficulty
             // 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 (ATTRIB_ID_MAX_COMBO, MaxCombo);
         }
 
         public override void FromDatabaseAttributes(IReadOnlyDictionary<int, double> values, IBeatmapOnlineInfo onlineInfo)
@@ -36,7 +35,6 @@ namespace osu.Game.Rulesets.Catch.Difficulty
 
             StarRating = values[ATTRIB_ID_AIM];
             ApproachRate = values[ATTRIB_ID_APPROACH_RATE];
-            MaxCombo = (int)values[ATTRIB_ID_MAX_COMBO];
         }
     }
 }

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

@@ -25,9 +25,12 @@ namespace osu.Game.Rulesets.Catch.Difficulty
 
         public override int Version => 20220701;
 
+        private readonly IWorkingBeatmap workingBeatmap;
+
         public CatchDifficultyCalculator(IRulesetInfo ruleset, IWorkingBeatmap beatmap)
             : base(ruleset, beatmap)
         {
+            workingBeatmap = beatmap;
         }
 
         protected override DifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
@@ -38,13 +41,24 @@ namespace osu.Game.Rulesets.Catch.Difficulty
             // 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;
 
-            return new CatchDifficultyAttributes
+            CatchDifficultyAttributes attributes = new CatchDifficultyAttributes
             {
                 StarRating = Math.Sqrt(skills[0].DifficultyValue()) * star_scaling_factor,
                 Mods = mods,
                 ApproachRate = preempt > 1200.0 ? -(preempt - 1800.0) / 120.0 : -(preempt - 1200.0) / 150.0 + 5.0,
                 MaxCombo = beatmap.HitObjects.Count(h => h is Fruit) + beatmap.HitObjects.OfType<JuiceStream>().SelectMany(j => j.NestedHitObjects).Count(h => !(h is TinyDroplet)),
             };
+
+            if (ComputeLegacyScoringValues)
+            {
+                CatchLegacyScoreSimulator sv1Simulator = new CatchLegacyScoreSimulator();
+                sv1Simulator.Simulate(workingBeatmap, beatmap, mods);
+                attributes.LegacyAccuracyScore = sv1Simulator.AccuracyScore;
+                attributes.LegacyComboScore = sv1Simulator.ComboScore;
+                attributes.LegacyBonusScoreRatio = sv1Simulator.BonusScoreRatio;
+            }
+
+            return attributes;
         }
 
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate)

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

@@ -0,0 +1,142 @@
+// 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.Mods;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Types;
+using osu.Game.Rulesets.Scoring;
+
+namespace osu.Game.Rulesets.Catch.Difficulty
+{
+    internal class CatchLegacyScoreSimulator : ILegacyScoreSimulator
+    {
+        public int AccuracyScore { get; private set; }
+
+        public int ComboScore { get; private set; }
+
+        public double BonusScoreRatio => legacyBonusScore == 0 ? 0 : (double)modernBonusScore / legacyBonusScore;
+
+        private int legacyBonusScore;
+        private int modernBonusScore;
+        private int combo;
+
+        private double scoreMultiplier;
+
+        public void Simulate(IWorkingBeatmap workingBeatmap, IBeatmap playableBeatmap, IReadOnlyList<Mod> mods)
+        {
+            IBeatmap baseBeatmap = workingBeatmap.Beatmap;
+
+            int countNormal = 0;
+            int countSlider = 0;
+            int countSpinner = 0;
+
+            foreach (HitObject obj in baseBeatmap.HitObjects)
+            {
+                switch (obj)
+                {
+                    case IHasPath:
+                        countSlider++;
+                        break;
+
+                    case IHasDuration:
+                        countSpinner++;
+                        break;
+
+                    default:
+                        countNormal++;
+                        break;
+                }
+            }
+
+            int objectCount = countNormal + countSlider + countSpinner;
+
+            int drainLength = 0;
+
+            if (baseBeatmap.HitObjects.Count > 0)
+            {
+                int breakLength = baseBeatmap.Breaks.Select(b => (int)Math.Round(b.EndTime) - (int)Math.Round(b.StartTime)).Sum();
+                drainLength = ((int)Math.Round(baseBeatmap.HitObjects[^1].StartTime) - (int)Math.Round(baseBeatmap.HitObjects[0].StartTime) - breakLength) / 1000;
+            }
+
+            int difficultyPeppyStars = (int)Math.Round(
+                (baseBeatmap.Difficulty.DrainRate
+                 + baseBeatmap.Difficulty.OverallDifficulty
+                 + baseBeatmap.Difficulty.CircleSize
+                 + Math.Clamp((float)objectCount / drainLength * 8, 0, 16)) / 38 * 5);
+
+            scoreMultiplier = difficultyPeppyStars * mods.Aggregate(1.0, (current, mod) => current * mod.ScoreMultiplier);
+
+            foreach (var obj in playableBeatmap.HitObjects)
+                simulateHit(obj);
+        }
+
+        private void simulateHit(HitObject hitObject)
+        {
+            bool increaseCombo = true;
+            bool addScoreComboMultiplier = false;
+
+            bool isBonus = false;
+            HitResult bonusResult = HitResult.None;
+
+            int scoreIncrease = 0;
+
+            switch (hitObject)
+            {
+                case TinyDroplet:
+                    scoreIncrease = 10;
+                    increaseCombo = false;
+                    break;
+
+                case Droplet:
+                    scoreIncrease = 100;
+                    break;
+
+                case Fruit:
+                    scoreIncrease = 300;
+                    addScoreComboMultiplier = true;
+                    increaseCombo = true;
+                    break;
+
+                case Banana:
+                    scoreIncrease = 1100;
+                    increaseCombo = false;
+                    isBonus = true;
+                    bonusResult = HitResult.LargeBonus;
+                    break;
+
+                case JuiceStream:
+                    foreach (var nested in hitObject.NestedHitObjects)
+                        simulateHit(nested);
+                    return;
+
+                case BananaShower:
+                    foreach (var nested in hitObject.NestedHitObjects)
+                        simulateHit(nested);
+                    return;
+            }
+
+            if (addScoreComboMultiplier)
+            {
+                // ReSharper disable once PossibleLossOfFraction (intentional to match osu-stable...)
+                ComboScore += (int)(Math.Max(0, combo - 1) * (scoreIncrease / 25 * scoreMultiplier));
+            }
+
+            if (isBonus)
+            {
+                legacyBonusScore += scoreIncrease;
+                modernBonusScore += Judgement.ToNumericResult(bonusResult);
+            }
+            else
+                AccuracyScore += scoreIncrease;
+
+            if (increaseCombo)
+                combo++;
+        }
+    }
+}

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

@@ -24,7 +24,6 @@ namespace osu.Game.Rulesets.Mania.Difficulty
             foreach (var v in base.ToDatabaseAttributes())
                 yield return v;
 
-            yield return (ATTRIB_ID_MAX_COMBO, MaxCombo);
             yield return (ATTRIB_ID_DIFFICULTY, StarRating);
             yield return (ATTRIB_ID_GREAT_HIT_WINDOW, GreatHitWindow);
         }
@@ -33,7 +32,6 @@ namespace osu.Game.Rulesets.Mania.Difficulty
         {
             base.FromDatabaseAttributes(values, onlineInfo);
 
-            MaxCombo = (int)values[ATTRIB_ID_MAX_COMBO];
             StarRating = values[ATTRIB_ID_DIFFICULTY];
             GreatHitWindow = values[ATTRIB_ID_GREAT_HIT_WINDOW];
         }

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

@@ -31,9 +31,13 @@ namespace osu.Game.Rulesets.Mania.Difficulty
 
         public override int Version => 20220902;
 
+        private readonly IWorkingBeatmap workingBeatmap;
+
         public ManiaDifficultyCalculator(IRulesetInfo ruleset, IWorkingBeatmap beatmap)
             : base(ruleset, beatmap)
         {
+            workingBeatmap = beatmap;
+
             isForCurrentRuleset = beatmap.BeatmapInfo.Ruleset.MatchesOnlineID(ruleset);
             originalOverallDifficulty = beatmap.BeatmapInfo.Difficulty.OverallDifficulty;
         }
@@ -46,15 +50,26 @@ namespace osu.Game.Rulesets.Mania.Difficulty
             HitWindows hitWindows = new ManiaHitWindows();
             hitWindows.SetDifficulty(beatmap.Difficulty.OverallDifficulty);
 
-            return new ManiaDifficultyAttributes
+            ManiaDifficultyAttributes attributes = new ManiaDifficultyAttributes
             {
                 StarRating = skills[0].DifficultyValue() * star_scaling_factor,
                 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),
-                MaxCombo = beatmap.HitObjects.Sum(maxComboForObject)
+                MaxCombo = beatmap.HitObjects.Sum(maxComboForObject),
             };
+
+            if (ComputeLegacyScoringValues)
+            {
+                ManiaLegacyScoreSimulator sv1Simulator = new ManiaLegacyScoreSimulator();
+                sv1Simulator.Simulate(workingBeatmap, beatmap, mods);
+                attributes.LegacyAccuracyScore = sv1Simulator.AccuracyScore;
+                attributes.LegacyComboScore = sv1Simulator.ComboScore;
+                attributes.LegacyBonusScoreRatio = sv1Simulator.BonusScoreRatio;
+            }
+
+            return attributes;
         }
 
         private static int maxComboForObject(HitObject hitObject)

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

@@ -0,0 +1,28 @@
+// 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.Collections.Generic;
+using System.Linq;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Mania.Mods;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Scoring;
+
+namespace osu.Game.Rulesets.Mania.Difficulty
+{
+    internal class ManiaLegacyScoreSimulator : ILegacyScoreSimulator
+    {
+        public int AccuracyScore => 0;
+        public int ComboScore { get; private set; }
+        public double BonusScoreRatio => 0;
+
+        public void Simulate(IWorkingBeatmap workingBeatmap, IBeatmap playableBeatmap, IReadOnlyList<Mod> mods)
+        {
+            double multiplier = mods.Where(m => m is not (ModHidden or ModHardRock or ModDoubleTime or ModFlashlight or ManiaModFadeIn))
+                                    .Select(m => m.ScoreMultiplier)
+                                    .Aggregate(1.0, (c, n) => c * n);
+
+            ComboScore = (int)(1000000 * multiplier);
+        }
+    }
+}

osu.Game.Rulesets.Mania/ManiaRuleset.cs

@@ -302,6 +302,8 @@ namespace osu.Game.Rulesets.Mania
 
         public int LegacyID => 3;
 
+        public ILegacyScoreSimulator CreateLegacyScoreSimulator() => new ManiaLegacyScoreSimulator();
+
         public override IConvertibleReplayFrame CreateConvertibleReplayFrame() => new ManiaReplayFrame();
 
         public override IRulesetConfigManager CreateConfig(SettingsStore? settings) => new ManiaRulesetConfigManager(settings, RulesetInfo);

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

@@ -93,7 +93,6 @@ namespace osu.Game.Rulesets.Osu.Difficulty
             yield return (ATTRIB_ID_SPEED, SpeedDifficulty);
             yield return (ATTRIB_ID_OVERALL_DIFFICULTY, OverallDifficulty);
             yield return (ATTRIB_ID_APPROACH_RATE, ApproachRate);
-            yield return (ATTRIB_ID_MAX_COMBO, MaxCombo);
             yield return (ATTRIB_ID_DIFFICULTY, StarRating);
 
             if (ShouldSerializeFlashlightRating())
@@ -111,7 +110,6 @@ namespace osu.Game.Rulesets.Osu.Difficulty
             SpeedDifficulty = values[ATTRIB_ID_SPEED];
             OverallDifficulty = values[ATTRIB_ID_OVERALL_DIFFICULTY];
             ApproachRate = values[ATTRIB_ID_APPROACH_RATE];
-            MaxCombo = (int)values[ATTRIB_ID_MAX_COMBO];
             StarRating = values[ATTRIB_ID_DIFFICULTY];
             FlashlightDifficulty = values.GetValueOrDefault(ATTRIB_ID_FLASHLIGHT);
             SliderFactor = values[ATTRIB_ID_SLIDER_FACTOR];

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

@@ -26,9 +26,12 @@ namespace osu.Game.Rulesets.Osu.Difficulty
 
         public override int Version => 20220902;
 
+        private readonly IWorkingBeatmap workingBeatmap;
+
         public OsuDifficultyCalculator(IRulesetInfo ruleset, IWorkingBeatmap beatmap)
             : base(ruleset, beatmap)
         {
+            workingBeatmap = beatmap;
         }
 
         protected override DifficultyAttributes CreateDifficultyAttributes(IBeatmap beatmap, Mod[] mods, Skill[] skills, double clockRate)
@@ -71,7 +74,9 @@ namespace osu.Game.Rulesets.Osu.Difficulty
                     Math.Pow(baseFlashlightPerformance, 1.1), 1.0 / 1.1
                 );
 
-            double starRating = basePerformance > 0.00001 ? Math.Cbrt(OsuPerformanceCalculator.PERFORMANCE_BASE_MULTIPLIER) * 0.027 * (Math.Cbrt(100000 / Math.Pow(2, 1 / 1.1) * basePerformance) + 4) : 0;
+            double starRating = basePerformance > 0.00001
+                ? Math.Cbrt(OsuPerformanceCalculator.PERFORMANCE_BASE_MULTIPLIER) * 0.027 * (Math.Cbrt(100000 / Math.Pow(2, 1 / 1.1) * basePerformance) + 4)
+                : 0;
 
             double preempt = IBeatmapDifficultyInfo.DifficultyRange(beatmap.Difficulty.ApproachRate, 1800, 1200, 450) / clockRate;
             double drainRate = beatmap.Difficulty.DrainRate;
@@ -86,7 +91,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty
 
             double hitWindowGreat = hitWindows.WindowFor(HitResult.Great) / clockRate;
 
-            return new OsuDifficultyAttributes
+            OsuDifficultyAttributes attributes = new OsuDifficultyAttributes
             {
                 StarRating = starRating,
                 Mods = mods,
@@ -103,6 +108,17 @@ namespace osu.Game.Rulesets.Osu.Difficulty
                 SliderCount = sliderCount,
                 SpinnerCount = spinnerCount,
             };
+
+            if (ComputeLegacyScoringValues)
+            {
+                OsuLegacyScoreSimulator sv1Simulator = new OsuLegacyScoreSimulator();
+                sv1Simulator.Simulate(workingBeatmap, beatmap, mods);
+                attributes.LegacyAccuracyScore = sv1Simulator.AccuracyScore;
+                attributes.LegacyComboScore = sv1Simulator.ComboScore;
+                attributes.LegacyBonusScoreRatio = sv1Simulator.BonusScoreRatio;
+            }
+
+            return attributes;
         }
 
         protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate)

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

@@ -0,0 +1,177 @@
+// 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.Mods;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Types;
+using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Rulesets.Scoring;
+
+namespace osu.Game.Rulesets.Osu.Difficulty
+{
+    internal class OsuLegacyScoreSimulator : ILegacyScoreSimulator
+    {
+        public int AccuracyScore { get; private set; }
+
+        public int ComboScore { get; private set; }
+
+        public double BonusScoreRatio => legacyBonusScore == 0 ? 0 : (double)modernBonusScore / legacyBonusScore;
+
+        private int legacyBonusScore;
+        private int modernBonusScore;
+        private int combo;
+
+        private double scoreMultiplier;
+        private IBeatmap playableBeatmap = null!;
+
+        public void Simulate(IWorkingBeatmap workingBeatmap, IBeatmap playableBeatmap, IReadOnlyList<Mod> mods)
+        {
+            this.playableBeatmap = playableBeatmap;
+
+            IBeatmap baseBeatmap = workingBeatmap.Beatmap;
+
+            int countNormal = 0;
+            int countSlider = 0;
+            int countSpinner = 0;
+
+            foreach (HitObject obj in workingBeatmap.Beatmap.HitObjects)
+            {
+                switch (obj)
+                {
+                    case IHasPath:
+                        countSlider++;
+                        break;
+
+                    case IHasDuration:
+                        countSpinner++;
+                        break;
+
+                    default:
+                        countNormal++;
+                        break;
+                }
+            }
+
+            int objectCount = countNormal + countSlider + countSpinner;
+
+            int drainLength = 0;
+
+            if (baseBeatmap.HitObjects.Count > 0)
+            {
+                int breakLength = baseBeatmap.Breaks.Select(b => (int)Math.Round(b.EndTime) - (int)Math.Round(b.StartTime)).Sum();
+                drainLength = ((int)Math.Round(baseBeatmap.HitObjects[^1].StartTime) - (int)Math.Round(baseBeatmap.HitObjects[0].StartTime) - breakLength) / 1000;
+            }
+
+            int difficultyPeppyStars = (int)Math.Round(
+                (baseBeatmap.Difficulty.DrainRate
+                 + baseBeatmap.Difficulty.OverallDifficulty
+                 + baseBeatmap.Difficulty.CircleSize
+                 + Math.Clamp((float)objectCount / drainLength * 8, 0, 16)) / 38 * 5);
+
+            scoreMultiplier = difficultyPeppyStars * mods.Aggregate(1.0, (current, mod) => current * mod.ScoreMultiplier);
+
+            foreach (var obj in playableBeatmap.HitObjects)
+                simulateHit(obj);
+        }
+
+        private void simulateHit(HitObject hitObject)
+        {
+            bool increaseCombo = true;
+            bool addScoreComboMultiplier = false;
+
+            bool isBonus = false;
+            HitResult bonusResult = HitResult.None;
+
+            int scoreIncrease = 0;
+
+            switch (hitObject)
+            {
+                case SliderHeadCircle:
+                case SliderTailCircle:
+                case SliderRepeat:
+                    scoreIncrease = 30;
+                    break;
+
+                case SliderTick:
+                    scoreIncrease = 10;
+                    break;
+
+                case SpinnerBonusTick:
+                    scoreIncrease = 1100;
+                    increaseCombo = false;
+                    isBonus = true;
+                    bonusResult = HitResult.LargeBonus;
+                    break;
+
+                case SpinnerTick:
+                    scoreIncrease = 100;
+                    increaseCombo = false;
+                    isBonus = true;
+                    bonusResult = HitResult.SmallBonus;
+                    break;
+
+                case HitCircle:
+                    scoreIncrease = 300;
+                    addScoreComboMultiplier = true;
+                    break;
+
+                case Slider:
+                    foreach (var nested in hitObject.NestedHitObjects)
+                        simulateHit(nested);
+
+                    scoreIncrease = 300;
+                    increaseCombo = false;
+                    addScoreComboMultiplier = true;
+                    break;
+
+                case Spinner spinner:
+                    // The spinner object applies a lenience because gameplay mechanics differ from osu-stable.
+                    // We'll redo the calculations to match osu-stable here...
+                    const double maximum_rotations_per_second = 477.0 / 60;
+                    double minimumRotationsPerSecond = IBeatmapDifficultyInfo.DifficultyRange(playableBeatmap.Difficulty.OverallDifficulty, 3, 5, 7.5);
+                    double secondsDuration = spinner.Duration / 1000;
+
+                    // The total amount of half spins possible for the entire spinner.
+                    int totalHalfSpinsPossible = (int)(secondsDuration * maximum_rotations_per_second * 2);
+                    // The amount of half spins that are required to successfully complete the spinner (i.e. get a 300).
+                    int halfSpinsRequiredForCompletion = (int)(secondsDuration * minimumRotationsPerSecond);
+                    // To be able to receive bonus points, the spinner must be rotated another 1.5 times.
+                    int halfSpinsRequiredBeforeBonus = halfSpinsRequiredForCompletion + 3;
+
+                    for (int i = 0; i <= totalHalfSpinsPossible; i++)
+                    {
+                        if (i > halfSpinsRequiredBeforeBonus && (i - halfSpinsRequiredBeforeBonus) % 2 == 0)
+                            simulateHit(new SpinnerBonusTick());
+                        else if (i > 1 && i % 2 == 0)
+                            simulateHit(new SpinnerTick());
+                    }
+
+                    scoreIncrease = 300;
+                    addScoreComboMultiplier = true;
+                    break;
+            }
+
+            if (addScoreComboMultiplier)
+            {
+                // ReSharper disable once PossibleLossOfFraction (intentional to match osu-stable...)
+                ComboScore += (int)(Math.Max(0, combo - 1) * (scoreIncrease / 25 * scoreMultiplier));
+            }
+
+            if (isBonus)
+            {
+                legacyBonusScore += scoreIncrease;
+                modernBonusScore += Judgement.ToNumericResult(bonusResult);
+            }
+            else
+                AccuracyScore += scoreIncrease;
+
+            if (increaseCombo)
+                combo++;
+        }
+    }
+}

osu.Game.Rulesets.Osu/OsuRuleset.cs

@@ -253,6 +253,8 @@ namespace osu.Game.Rulesets.Osu
 
         public int LegacyID => 0;
 
+        public ILegacyScoreSimulator CreateLegacyScoreSimulator() => new OsuLegacyScoreSimulator();
+
         public override IConvertibleReplayFrame CreateConvertibleReplayFrame() => new OsuReplayFrame();
 
         public override IRulesetConfigManager CreateConfig(SettingsStore? settings) => new OsuRulesetConfigManager(settings, RulesetInfo);

osu.Game.Rulesets.Taiko.Tests/TestSceneFlyingHits.cs

@@ -38,7 +38,7 @@ namespace osu.Game.Rulesets.Taiko.Tests
 
         private void addFlyingHit(HitType hitType)
         {
-            var tick = new DrumRollTick { HitWindows = HitWindows.Empty, StartTime = DrawableRuleset.Playfield.Time.Current };
+            var tick = new DrumRollTick(new DrumRoll()) { HitWindows = HitWindows.Empty, StartTime = DrawableRuleset.Playfield.Time.Current };
 
             DrawableDrumRollTick h;
             DrawableRuleset.Playfield.Add(h = new DrawableDrumRollTick(tick) { JudgementType = hitType });

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

@@ -48,7 +48,6 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
             foreach (var v in base.ToDatabaseAttributes())
                 yield return v;
 
-            yield return (ATTRIB_ID_MAX_COMBO, MaxCombo);
             yield return (ATTRIB_ID_DIFFICULTY, StarRating);
             yield return (ATTRIB_ID_GREAT_HIT_WINDOW, GreatHitWindow);
         }
@@ -57,7 +56,6 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
         {
             base.FromDatabaseAttributes(values, onlineInfo);
 
-            MaxCombo = (int)values[ATTRIB_ID_MAX_COMBO];
             StarRating = values[ATTRIB_ID_DIFFICULTY];
             GreatHitWindow = values[ATTRIB_ID_GREAT_HIT_WINDOW];
         }

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

@@ -25,9 +25,12 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
 
         public override int Version => 20220902;
 
+        private readonly IWorkingBeatmap workingBeatmap;
+
         public TaikoDifficultyCalculator(IRulesetInfo ruleset, IWorkingBeatmap beatmap)
             : base(ruleset, beatmap)
         {
+            workingBeatmap = beatmap;
         }
 
         protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate)
@@ -84,7 +87,7 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
             HitWindows hitWindows = new TaikoHitWindows();
             hitWindows.SetDifficulty(beatmap.Difficulty.OverallDifficulty);
 
-            return new TaikoDifficultyAttributes
+            TaikoDifficultyAttributes attributes = new TaikoDifficultyAttributes
             {
                 StarRating = starRating,
                 Mods = mods,
@@ -95,6 +98,17 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
                 GreatHitWindow = hitWindows.WindowFor(HitResult.Great) / clockRate,
                 MaxCombo = beatmap.HitObjects.Count(h => h is Hit),
             };
+
+            if (ComputeLegacyScoringValues)
+            {
+                TaikoLegacyScoreSimulator sv1Simulator = new TaikoLegacyScoreSimulator();
+                sv1Simulator.Simulate(workingBeatmap, beatmap, mods);
+                attributes.LegacyAccuracyScore = sv1Simulator.AccuracyScore;
+                attributes.LegacyComboScore = sv1Simulator.ComboScore;
+                attributes.LegacyBonusScoreRatio = sv1Simulator.BonusScoreRatio;
+            }
+
+            return attributes;
         }
 
         /// <summary>

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

@@ -0,0 +1,202 @@
+// 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.Mods;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Types;
+using osu.Game.Rulesets.Scoring;
+using osu.Game.Rulesets.Taiko.Objects;
+
+namespace osu.Game.Rulesets.Taiko.Difficulty
+{
+    internal class TaikoLegacyScoreSimulator : ILegacyScoreSimulator
+    {
+        public int AccuracyScore { get; private set; }
+
+        public int ComboScore { get; private set; }
+
+        public double BonusScoreRatio => legacyBonusScore == 0 ? 0 : (double)modernBonusScore / legacyBonusScore;
+
+        private int legacyBonusScore;
+        private int modernBonusScore;
+        private int combo;
+
+        private double modMultiplier;
+        private int difficultyPeppyStars;
+        private IBeatmap playableBeatmap = null!;
+        private IReadOnlyList<Mod> mods = null!;
+
+        public void Simulate(IWorkingBeatmap workingBeatmap, IBeatmap playableBeatmap, IReadOnlyList<Mod> mods)
+        {
+            this.playableBeatmap = playableBeatmap;
+            this.mods = mods;
+
+            IBeatmap baseBeatmap = workingBeatmap.Beatmap;
+
+            int countNormal = 0;
+            int countSlider = 0;
+            int countSpinner = 0;
+
+            foreach (HitObject obj in baseBeatmap.HitObjects)
+            {
+                switch (obj)
+                {
+                    case IHasPath:
+                        countSlider++;
+                        break;
+
+                    case IHasDuration:
+                        countSpinner++;
+                        break;
+
+                    default:
+                        countNormal++;
+                        break;
+                }
+            }
+
+            int objectCount = countNormal + countSlider + countSpinner;
+
+            int drainLength = 0;
+
+            if (baseBeatmap.HitObjects.Count > 0)
+            {
+                int breakLength = baseBeatmap.Breaks.Select(b => (int)Math.Round(b.EndTime) - (int)Math.Round(b.StartTime)).Sum();
+                drainLength = ((int)Math.Round(baseBeatmap.HitObjects[^1].StartTime) - (int)Math.Round(baseBeatmap.HitObjects[0].StartTime) - breakLength) / 1000;
+            }
+
+            difficultyPeppyStars = (int)Math.Round(
+                (baseBeatmap.Difficulty.DrainRate
+                 + baseBeatmap.Difficulty.OverallDifficulty
+                 + baseBeatmap.Difficulty.CircleSize
+                 + Math.Clamp((float)objectCount / drainLength * 8, 0, 16)) / 38 * 5);
+
+            modMultiplier = mods.Aggregate(1.0, (current, mod) => current * mod.ScoreMultiplier);
+
+            foreach (var obj in playableBeatmap.HitObjects)
+                simulateHit(obj);
+        }
+
+        private void simulateHit(HitObject hitObject)
+        {
+            bool increaseCombo = true;
+            bool addScoreComboMultiplier = false;
+
+            bool isBonus = false;
+            HitResult bonusResult = HitResult.None;
+
+            int scoreIncrease = 0;
+
+            switch (hitObject)
+            {
+                case SwellTick:
+                    scoreIncrease = 300;
+                    increaseCombo = false;
+                    break;
+
+                case DrumRollTick:
+                    scoreIncrease = 300;
+                    increaseCombo = false;
+                    isBonus = true;
+                    bonusResult = HitResult.SmallBonus;
+                    break;
+
+                case Swell swell:
+                    // The taiko swell generally does not match the osu-stable implementation in any way.
+                    // We'll redo the calculations to match osu-stable here...
+                    double minimumRotationsPerSecond = IBeatmapDifficultyInfo.DifficultyRange(playableBeatmap.Difficulty.OverallDifficulty, 3, 5, 7.5);
+                    double secondsDuration = swell.Duration / 1000;
+
+                    // The amount of half spins that are required to successfully complete the spinner (i.e. get a 300).
+                    int halfSpinsRequiredForCompletion = (int)(secondsDuration * minimumRotationsPerSecond);
+
+                    halfSpinsRequiredForCompletion = (int)Math.Max(1, halfSpinsRequiredForCompletion * 1.65f);
+
+                    if (mods.Any(m => m is ModDoubleTime))
+                        halfSpinsRequiredForCompletion = Math.Max(1, (int)(halfSpinsRequiredForCompletion * 0.75f));
+                    if (mods.Any(m => m is ModHalfTime))
+                        halfSpinsRequiredForCompletion = Math.Max(1, (int)(halfSpinsRequiredForCompletion * 1.5f));
+
+                    for (int i = 0; i <= halfSpinsRequiredForCompletion; i++)
+                        simulateHit(new SwellTick());
+
+                    scoreIncrease = 300;
+                    addScoreComboMultiplier = true;
+                    increaseCombo = false;
+                    isBonus = true;
+                    bonusResult = HitResult.LargeBonus;
+                    break;
+
+                case Hit:
+                    scoreIncrease = 300;
+                    addScoreComboMultiplier = true;
+                    break;
+
+                case DrumRoll:
+                    foreach (var nested in hitObject.NestedHitObjects)
+                        simulateHit(nested);
+                    return;
+            }
+
+            if (hitObject is DrumRollTick tick)
+            {
+                if (playableBeatmap.ControlPointInfo.EffectPointAt(tick.Parent.StartTime).KiaiMode)
+                    scoreIncrease = (int)(scoreIncrease * 1.2f);
+
+                if (tick.IsStrong)
+                    scoreIncrease += scoreIncrease / 5;
+            }
+
+            // The score increase directly contributed to by the combo-multiplied portion.
+            int comboScoreIncrease = 0;
+
+            if (addScoreComboMultiplier)
+            {
+                int oldScoreIncrease = scoreIncrease;
+
+                // ReSharper disable once PossibleLossOfFraction (intentional to match osu-stable...)
+                scoreIncrease += (int)(scoreIncrease / 35 * 2 * (difficultyPeppyStars + 1) * modMultiplier) * (Math.Min(100, combo) / 10);
+
+                if (hitObject is Swell)
+                {
+                    if (playableBeatmap.ControlPointInfo.EffectPointAt(hitObject.GetEndTime()).KiaiMode)
+                        scoreIncrease = (int)(scoreIncrease * 1.2f);
+                }
+                else
+                {
+                    if (playableBeatmap.ControlPointInfo.EffectPointAt(hitObject.StartTime).KiaiMode)
+                        scoreIncrease = (int)(scoreIncrease * 1.2f);
+                }
+
+                comboScoreIncrease = scoreIncrease - oldScoreIncrease;
+            }
+
+            if (hitObject is Swell || (hitObject is TaikoStrongableHitObject strongable && strongable.IsStrong))
+            {
+                scoreIncrease *= 2;
+                comboScoreIncrease *= 2;
+            }
+
+            scoreIncrease -= comboScoreIncrease;
+
+            if (addScoreComboMultiplier)
+                ComboScore += comboScoreIncrease;
+
+            if (isBonus)
+            {
+                legacyBonusScore += scoreIncrease;
+                modernBonusScore += Judgement.ToNumericResult(bonusResult);
+            }
+            else
+                AccuracyScore += scoreIncrease;
+
+            if (increaseCombo)
+                combo++;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/DrumRoll.cs

@@ -90,7 +90,7 @@ namespace osu.Game.Rulesets.Taiko.Objects
             {
                 cancellationToken.ThrowIfCancellationRequested();
 
-                AddNested(new DrumRollTick
+                AddNested(new DrumRollTick(this)
                 {
                     FirstTick = first,
                     TickSpacing = tickSpacing,

osu.Game.Rulesets.Taiko/Objects/DrumRollTick.cs

@@ -9,6 +9,8 @@ namespace osu.Game.Rulesets.Taiko.Objects
 {
     public class DrumRollTick : TaikoStrongableHitObject
     {
+        public readonly DrumRoll Parent;
+
         /// <summary>
         /// Whether this is the first (initial) tick of the slider.
         /// </summary>
@@ -25,6 +27,11 @@ namespace osu.Game.Rulesets.Taiko.Objects
         /// </summary>
         public double HitWindow => TickSpacing / 2;
 
+        public DrumRollTick(DrumRoll parent)
+        {
+            Parent = parent;
+        }
+
         public override Judgement CreateJudgement() => new TaikoDrumRollTickJudgement();
 
         protected override HitWindows CreateHitWindows() => HitWindows.Empty;

osu.Game.Rulesets.Taiko/TaikoRuleset.cs

@@ -197,6 +197,8 @@ namespace osu.Game.Rulesets.Taiko
 
         public int LegacyID => 1;
 
+        public ILegacyScoreSimulator CreateLegacyScoreSimulator() => new TaikoLegacyScoreSimulator();
+
         public override IConvertibleReplayFrame CreateConvertibleReplayFrame() => new TaikoReplayFrame();
 
         public override IRulesetConfigManager CreateConfig(SettingsStore? settings) => new TaikoRulesetConfigManager(settings, RulesetInfo);

osu.Game/BackgroundBeatmapProcessor.cs

@@ -14,8 +14,11 @@ using osu.Framework.Graphics;
 using osu.Framework.Logging;
 using osu.Game.Beatmaps;
 using osu.Game.Database;
+using osu.Game.Overlays;
+using osu.Game.Overlays.Notifications;
 using osu.Game.Rulesets;
 using osu.Game.Scoring;
+using osu.Game.Scoring.Legacy;
 using osu.Game.Screens.Play;
 
 namespace osu.Game
@@ -25,6 +28,9 @@ namespace osu.Game
         [Resolved]
         private RulesetStore rulesetStore { get; set; } = null!;
 
+        [Resolved]
+        private BeatmapManager beatmapManager { get; set; } = null!;
+
         [Resolved]
         private ScoreManager scoreManager { get; set; } = null!;
 
@@ -40,19 +46,23 @@ namespace osu.Game
         [Resolved]
         private ILocalUserPlayInfo? localUserPlayInfo { get; set; }
 
+        [Resolved]
+        private INotificationOverlay? notificationOverlay { get; set; }
+
         protected virtual int TimeToSleepDuringGameplay => 30000;
 
         protected override void LoadComplete()
         {
             base.LoadComplete();
 
-            Task.Run(() =>
+            Task.Factory.StartNew(() =>
             {
                 Logger.Log("Beginning background beatmap processing..");
                 checkForOutdatedStarRatings();
                 processBeatmapSetsWithMissingMetrics();
                 processScoresWithMissingStatistics();
-            }).ContinueWith(t =>
+                convertLegacyTotalScoreToStandardised();
+            }, TaskCreationOptions.LongRunning).ContinueWith(t =>
             {
                 if (t.Exception?.InnerException is ObjectDisposedException)
                 {
@@ -121,11 +131,7 @@ namespace osu.Game
 
             foreach (var id in beatmapSetIds)
             {
-                while (localUserPlayInfo?.IsPlaying.Value == true)
+                sleepIfRequired();
-                {
-                    Logger.Log("Background processing sleeping due to active gameplay...");
-                    Thread.Sleep(TimeToSleepDuringGameplay);
-                }
 
                 realmAccess.Run(r =>
                 {
@@ -166,11 +172,7 @@ namespace osu.Game
 
             foreach (var id in scoreIds)
             {
-                while (localUserPlayInfo?.IsPlaying.Value == true)
+                sleepIfRequired();
-                {
-                    Logger.Log("Background processing sleeping due to active gameplay...");
-                    Thread.Sleep(TimeToSleepDuringGameplay);
-                }
 
                 try
                 {
@@ -187,11 +189,98 @@ namespace osu.Game
 
                     Logger.Log($"Populated maximum statistics for score {id}");
                 }
+                catch (ObjectDisposedException)
+                {
+                    throw;
+                }
                 catch (Exception e)
                 {
                     Logger.Log(@$"Failed to populate maximum statistics for {id}: {e}");
                 }
             }
         }
+
+        private void convertLegacyTotalScoreToStandardised()
+        {
+            Logger.Log("Querying for scores that need total score conversion...");
+
+            HashSet<Guid> scoreIds = realmAccess.Run(r => new HashSet<Guid>(r.All<ScoreInfo>().Where(s => s.TotalScoreVersion == 30000002).AsEnumerable().Select(s => s.ID)));
+
+            Logger.Log($"Found {scoreIds.Count} scores which require total score conversion.");
+
+            if (scoreIds.Count == 0)
+                return;
+
+            ProgressNotification notification = new ProgressNotification { State = ProgressNotificationState.Active };
+
+            notificationOverlay?.Post(notification);
+
+            int processedCount = 0;
+            int failedCount = 0;
+
+            foreach (var id in scoreIds)
+            {
+                if (notification.State == ProgressNotificationState.Cancelled)
+                    break;
+
+                notification.Text = $"Upgrading scores to new scoring algorithm ({processedCount} of {scoreIds.Count})";
+                notification.Progress = (float)processedCount / scoreIds.Count;
+
+                sleepIfRequired();
+
+                try
+                {
+                    var score = scoreManager.Query(s => s.ID == id);
+                    long newTotalScore = StandardisedScoreMigrationTools.ConvertFromLegacyTotalScore(score, beatmapManager);
+
+                    // Can't use async overload because we're not on the update thread.
+                    // ReSharper disable once MethodHasAsyncOverload
+                    realmAccess.Write(r =>
+                    {
+                        ScoreInfo s = r.Find<ScoreInfo>(id);
+                        s.TotalScore = newTotalScore;
+                        s.TotalScoreVersion = LegacyScoreEncoder.LATEST_VERSION;
+                    });
+
+                    Logger.Log($"Converted total score for score {id}");
+                    ++processedCount;
+                }
+                catch (ObjectDisposedException)
+                {
+                    throw;
+                }
+                catch (Exception e)
+                {
+                    Logger.Log($"Failed to convert total score for {id}: {e}");
+                    ++failedCount;
+                }
+            }
+
+            if (processedCount == scoreIds.Count)
+            {
+                notification.CompletionText = $"{processedCount} score(s) have been upgraded to the new scoring algorithm";
+                notification.Progress = 1;
+                notification.State = ProgressNotificationState.Completed;
+            }
+            else
+            {
+                notification.Text = $"{processedCount} of {scoreIds.Count} score(s) have been upgraded to the new scoring algorithm.";
+
+                // We may have arrived here due to user cancellation or completion with failures.
+                if (failedCount > 0)
+                    notification.Text += $" Check logs for issues with {failedCount} failed upgrades.";
+
+                notification.State = ProgressNotificationState.Cancelled;
+            }
+        }
+
+        private void sleepIfRequired()
+        {
+            while (localUserPlayInfo?.IsPlaying.Value == true)
+            {
+                Logger.Log("Background processing sleeping due to active gameplay...");
+                Thread.Sleep(TimeToSleepDuringGameplay);
+            }
+        }
     }
 }

osu.Game/Database/RealmAccess.cs

@@ -78,8 +78,9 @@ namespace osu.Game.Database
         /// 28   2023-06-08    Added IsLegacyScore to ScoreInfo, parsed from replay files.
         /// 29   2023-06-12    Run migration of old lazer scores to be best-effort in the new scoring number space. No actual realm changes.
         /// 30   2023-06-16    Run migration of old lazer scores again. This time with more correct rounding considerations.
+        /// 31   2023-06-26    Add Version and LegacyTotalScore to ScoreInfo, set Version to 30000002 and copy TotalScore into LegacyTotalScore for legacy scores.
         /// </summary>
-        private const int schema_version = 30;
+        private const int schema_version = 31;
 
         /// <summary>
         /// Lock object which is held during <see cref="BlockAllOperations"/> sections, blocking realm retrieval during blocking periods.
@@ -966,6 +967,25 @@ namespace osu.Game.Database
 
                     break;
                 }
+
+                case 31:
+                {
+                    foreach (var score in migration.NewRealm.All<ScoreInfo>())
+                    {
+                        if (score.IsLegacyScore && score.Ruleset.IsLegacyRuleset())
+                        {
+                            // Scores with this version will trigger the score upgrade process in BackgroundBeatmapProcessor.
+                            score.TotalScoreVersion = 30000002;
+
+                            // Transfer known legacy scores to a permanent storage field for preservation.
+                            score.LegacyTotalScore = score.TotalScore;
+                        }
+                        else
+                            score.TotalScoreVersion = LegacyScoreEncoder.LATEST_VERSION;
+                    }
+
+                    break;
+                }
             }
 
             Logger.Log($"Migration completed in {stopwatch.ElapsedMilliseconds}ms");

osu.Game/Database/StandardisedScoreMigrationTools.cs

@@ -3,8 +3,11 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using osu.Game.Beatmaps;
+using osu.Game.Rulesets;
+using osu.Game.Rulesets.Difficulty;
 using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Scoring;
@@ -185,6 +188,100 @@ namespace osu.Game.Database
             return (long)Math.Round((1000000 * (accuracyPortion * accuracyScore + (1 - accuracyPortion) * comboScore) + bonusScore) * modMultiplier);
         }
 
+        /// <summary>
+        /// Converts from <see cref="ScoreInfo.LegacyTotalScore"/> to the new standardised scoring of <see cref="ScoreProcessor"/>.
+        /// </summary>
+        /// <param name="score">The score to convert the total score of.</param>
+        /// <param name="beatmaps">A <see cref="BeatmapManager"/> used for <see cref="WorkingBeatmap"/> lookups.</param>
+        /// <returns>The standardised total score.</returns>
+        public static long ConvertFromLegacyTotalScore(ScoreInfo score, BeatmapManager beatmaps)
+        {
+            if (!score.IsLegacyScore)
+                return score.TotalScore;
+
+            WorkingBeatmap beatmap = beatmaps.GetWorkingBeatmap(score.BeatmapInfo);
+            Ruleset ruleset = score.Ruleset.CreateInstance();
+
+            if (ruleset is not ILegacyRuleset legacyRuleset)
+                return score.TotalScore;
+
+            var playableBeatmap = beatmap.GetPlayableBeatmap(ruleset.RulesetInfo, score.Mods);
+
+            if (playableBeatmap.HitObjects.Count == 0)
+                throw new InvalidOperationException("Beatmap contains no hit objects!");
+
+            ILegacyScoreSimulator sv1Simulator = legacyRuleset.CreateLegacyScoreSimulator();
+
+            sv1Simulator.Simulate(beatmap, playableBeatmap, score.Mods);
+
+            return ConvertFromLegacyTotalScore(score, new DifficultyAttributes
+            {
+                LegacyAccuracyScore = sv1Simulator.AccuracyScore,
+                LegacyComboScore = sv1Simulator.ComboScore,
+                LegacyBonusScoreRatio = sv1Simulator.BonusScoreRatio
+            });
+        }
+
+        /// <summary>
+        /// Converts from <see cref="ScoreInfo.LegacyTotalScore"/> to the new standardised scoring of <see cref="ScoreProcessor"/>.
+        /// </summary>
+        /// <param name="score">The score to convert the total score of.</param>
+        /// <param name="attributes">Difficulty attributes providing the legacy scoring values
+        /// (<see cref="DifficultyAttributes.LegacyAccuracyScore"/>, <see cref="DifficultyAttributes.LegacyComboScore"/>, and <see cref="DifficultyAttributes.LegacyBonusScoreRatio"/>)
+        /// for the beatmap which the score was set on.</param>
+        /// <returns>The standardised total score.</returns>
+        public static long ConvertFromLegacyTotalScore(ScoreInfo score, DifficultyAttributes attributes)
+        {
+            if (!score.IsLegacyScore)
+                return score.TotalScore;
+
+            Debug.Assert(score.LegacyTotalScore != null);
+
+            int maximumLegacyAccuracyScore = attributes.LegacyAccuracyScore;
+            int maximumLegacyComboScore = attributes.LegacyComboScore;
+            double maximumLegacyBonusRatio = attributes.LegacyBonusScoreRatio;
+            double modMultiplier = score.Mods.Select(m => m.ScoreMultiplier).Aggregate(1.0, (c, n) => c * n);
+
+            // The part of total score that doesn't include bonus.
+            int maximumLegacyBaseScore = maximumLegacyAccuracyScore + maximumLegacyComboScore;
+
+            // The combo proportion is calculated as a proportion of maximumLegacyBaseScore.
+            double comboProportion = Math.Min(1, (double)score.LegacyTotalScore / maximumLegacyBaseScore);
+
+            // The bonus proportion makes up the rest of the score that exceeds maximumLegacyBaseScore.
+            double bonusProportion = Math.Max(0, ((long)score.LegacyTotalScore - maximumLegacyBaseScore) * maximumLegacyBonusRatio);
+
+            switch (score.Ruleset.OnlineID)
+            {
+                case 0:
+                    return (long)Math.Round((
+                        700000 * comboProportion
+                        + 300000 * Math.Pow(score.Accuracy, 10)
+                        + bonusProportion) * modMultiplier);
+
+                case 1:
+                    return (long)Math.Round((
+                        250000 * comboProportion
+                        + 750000 * Math.Pow(score.Accuracy, 3.6)
+                        + bonusProportion) * modMultiplier);
+
+                case 2:
+                    return (long)Math.Round((
+                        600000 * comboProportion
+                        + 400000 * score.Accuracy
+                        + bonusProportion) * modMultiplier);
+
+                case 3:
+                    return (long)Math.Round((
+                        990000 * comboProportion
+                        + 10000 * Math.Pow(score.Accuracy, 2 + 2 * score.Accuracy)
+                        + bonusProportion) * modMultiplier);
+
+                default:
+                    return score.TotalScore;
+            }
+        }
+
         private class FakeHit : HitObject
         {
             private readonly Judgement judgement;

osu.Game/Rulesets/Difficulty/DifficultyAttributes.cs

@@ -3,10 +3,10 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using Newtonsoft.Json;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Scoring;
 
 namespace osu.Game.Rulesets.Difficulty
 {
@@ -27,6 +27,9 @@ namespace osu.Game.Rulesets.Difficulty
         protected const int ATTRIB_ID_FLASHLIGHT = 17;
         protected const int ATTRIB_ID_SLIDER_FACTOR = 19;
         protected const int ATTRIB_ID_SPEED_NOTE_COUNT = 21;
+        protected const int ATTRIB_ID_LEGACY_ACCURACY_SCORE = 23;
+        protected const int ATTRIB_ID_LEGACY_COMBO_SCORE = 25;
+        protected const int ATTRIB_ID_LEGACY_BONUS_SCORE_RATIO = 27;
 
         /// <summary>
         /// The mods which were applied to the beatmap.
@@ -45,6 +48,22 @@ namespace osu.Game.Rulesets.Difficulty
         [JsonProperty("max_combo", Order = -2)]
         public int MaxCombo { get; set; }
 
+        /// <summary>
+        /// The accuracy portion of the legacy (ScoreV1) total score.
+        /// </summary>
+        public int LegacyAccuracyScore { get; set; }
+
+        /// <summary>
+        /// The combo-multiplied portion of the legacy (ScoreV1) total score.
+        /// </summary>
+        public int LegacyComboScore { get; set; }
+
+        /// <summary>
+        /// A ratio of <c>new_bonus_score / old_bonus_score</c> for converting the bonus score of legacy scores to the new scoring.
+        /// This is made up of all judgements that would be <see cref="HitResult.SmallBonus"/> or <see cref="HitResult.LargeBonus"/>.
+        /// </summary>
+        public double LegacyBonusScoreRatio { get; set; }
+
         /// <summary>
         /// Creates new <see cref="DifficultyAttributes"/>.
         /// </summary>
@@ -69,7 +88,13 @@ namespace osu.Game.Rulesets.Difficulty
         /// <remarks>
         /// See: osu_difficulty_attribs table.
         /// </remarks>
-        public virtual IEnumerable<(int attributeId, object value)> ToDatabaseAttributes() => Enumerable.Empty<(int, object)>();
+        public virtual IEnumerable<(int attributeId, object value)> ToDatabaseAttributes()
+        {
+            yield return (ATTRIB_ID_MAX_COMBO, MaxCombo);
+            yield return (ATTRIB_ID_LEGACY_ACCURACY_SCORE, LegacyAccuracyScore);
+            yield return (ATTRIB_ID_LEGACY_COMBO_SCORE, LegacyComboScore);
+            yield return (ATTRIB_ID_LEGACY_BONUS_SCORE_RATIO, LegacyBonusScoreRatio);
+        }
 
         /// <summary>
         /// Reads osu-web database attribute mappings into this <see cref="DifficultyAttributes"/> object.
@@ -78,6 +103,10 @@ namespace osu.Game.Rulesets.Difficulty
         /// <param name="onlineInfo">The <see cref="IBeatmapOnlineInfo"/> where more information about the beatmap may be extracted from (such as AR/CS/OD/etc).</param>
         public virtual void FromDatabaseAttributes(IReadOnlyDictionary<int, double> values, IBeatmapOnlineInfo onlineInfo)
         {
+            MaxCombo = (int)values[ATTRIB_ID_MAX_COMBO];
+            LegacyAccuracyScore = (int)values[ATTRIB_ID_LEGACY_ACCURACY_SCORE];
+            LegacyComboScore = (int)values[ATTRIB_ID_LEGACY_COMBO_SCORE];
+            LegacyBonusScoreRatio = (int)values[ATTRIB_ID_LEGACY_BONUS_SCORE_RATIO];
         }
     }
 }

osu.Game/Rulesets/Difficulty/DifficultyCalculator.cs

@@ -23,6 +23,13 @@ namespace osu.Game.Rulesets.Difficulty
 {
     public abstract class DifficultyCalculator
     {
+        /// <summary>
+        /// Whether legacy scoring values (ScoreV1) should be computed to populate the difficulty attributes
+        /// <see cref="DifficultyAttributes.LegacyAccuracyScore"/>, <see cref="DifficultyAttributes.LegacyComboScore"/>,
+        /// and <see cref="DifficultyAttributes.LegacyBonusScoreRatio"/>.
+        /// </summary>
+        public bool ComputeLegacyScoringValues;
+
         /// <summary>
         /// The beatmap for which difficulty will be calculated.
         /// </summary>

osu.Game/Rulesets/ILegacyRuleset.cs

@@ -1,6 +1,8 @@
 // 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 osu.Game.Rulesets.Scoring;
+
 namespace osu.Game.Rulesets
 {
     public interface ILegacyRuleset
@@ -11,5 +13,7 @@ namespace osu.Game.Rulesets
         /// Identifies the server-side ID of a legacy ruleset.
         /// </summary>
         int LegacyID { get; }
+
+        ILegacyScoreSimulator CreateLegacyScoreSimulator();
     }
 }

osu.Game/Rulesets/Scoring/ILegacyScoreSimulator.cs

@@ -0,0 +1,40 @@
+// 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.Collections.Generic;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Mods;
+
+namespace osu.Game.Rulesets.Scoring
+{
+    /// <summary>
+    /// Generates attributes which are required to calculate old-style Score V1 scores.
+    /// </summary>
+    public interface ILegacyScoreSimulator
+    {
+        /// <summary>
+        /// The accuracy portion of the legacy (ScoreV1) total score.
+        /// </summary>
+        int AccuracyScore { get; }
+
+        /// <summary>
+        /// The combo-multiplied portion of the legacy (ScoreV1) total score.
+        /// </summary>
+        int ComboScore { get; }
+
+        /// <summary>
+        /// A ratio of <c>new_bonus_score / old_bonus_score</c> for converting the bonus score of legacy scores to the new scoring.
+        /// This is made up of all judgements that would be <see cref="HitResult.SmallBonus"/> or <see cref="HitResult.LargeBonus"/>.
+        /// </summary>
+        double BonusScoreRatio { get; }
+
+        /// <summary>
+        /// Performs the simulation, computing the maximum <see cref="AccuracyScore"/>, <see cref="ComboScore"/>,
+        /// and <see cref="BonusScoreRatio"/> achievable for the given beatmap.
+        /// </summary>
+        /// <param name="workingBeatmap">The working beatmap.</param>
+        /// <param name="playableBeatmap">A playable version of the beatmap for the ruleset.</param>
+        /// <param name="mods">The applied mods.</param>
+        void Simulate(IWorkingBeatmap workingBeatmap, IBeatmap playableBeatmap, IReadOnlyList<Mod> mods);
+    }
+}

osu.Game/Scoring/Legacy/LegacyScoreEncoder.cs

@@ -28,10 +28,11 @@ namespace osu.Game.Scoring.Legacy
         /// <remarks>
         /// <list type="bullet">
         /// <item><description>30000001: Appends <see cref="LegacyReplaySoloScoreInfo"/> to the end of scores.</description></item>
-        /// <item><description>30000002: Score stored to replay calculated using the Score V2 algorithm.</description></item>
+        /// <item><description>30000002: Score stored to replay calculated using the Score V2 algorithm. Legacy scores on this version are candidate to Score V1 -> V2 conversion.</description></item>
+        /// <item><description>30000003: First version after converting legacy total score to standardised.</description></item>
         /// </list>
         /// </remarks>
-        public const int LATEST_VERSION = 30000002;
+        public const int LATEST_VERSION = 30000003;
 
         /// <summary>
         /// The first stable-compatible YYYYMMDD format version given to lazer usage of replays.

osu.Game/Scoring/Legacy/ScoreInfoExtensions.cs

@@ -14,13 +14,7 @@ namespace osu.Game.Scoring.Legacy
             => getDisplayScore(scoreProcessor.Ruleset.RulesetInfo.OnlineID, scoreProcessor.TotalScore.Value, mode, scoreProcessor.MaximumStatistics);
 
         public static long GetDisplayScore(this ScoreInfo scoreInfo, ScoringMode mode)
-        {
+            => getDisplayScore(scoreInfo.Ruleset.OnlineID, scoreInfo.TotalScore, mode, scoreInfo.MaximumStatistics);
-            // Temporary to not scale stable scores that are already in the XX-millions with the classic scoring mode.
-            if (scoreInfo.IsLegacyScore)
-                return scoreInfo.TotalScore;
-
-            return getDisplayScore(scoreInfo.Ruleset.OnlineID, scoreInfo.TotalScore, mode, scoreInfo.MaximumStatistics);
-        }
 
         private static long getDisplayScore(int rulesetId, long score, ScoringMode mode, IReadOnlyDictionary<HitResult, int> maximumStatistics)
         {

osu.Game/Scoring/ScoreImporter.cs

@@ -88,6 +88,11 @@ namespace osu.Game.Scoring
             // this requires: max combo, statistics, max statistics (where available), and mods to already be populated on the score.
             if (StandardisedScoreMigrationTools.ShouldMigrateToNewStandardised(model))
                 model.TotalScore = StandardisedScoreMigrationTools.GetNewStandardised(model);
+            else if (model.IsLegacyScore)
+            {
+                model.LegacyTotalScore = model.TotalScore;
+                model.TotalScore = StandardisedScoreMigrationTools.ConvertFromLegacyTotalScore(model, beatmaps());
+            }
         }
 
         /// <summary>

osu.Game/Scoring/ScoreInfo.cs

@@ -15,6 +15,7 @@ using osu.Game.Online.API.Requests.Responses;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Scoring;
+using osu.Game.Scoring.Legacy;
 using osu.Game.Users;
 using osu.Game.Utils;
 using Realms;
@@ -53,6 +54,26 @@ namespace osu.Game.Scoring
 
         public long TotalScore { get; set; }
 
+        /// <summary>
+        /// The version of processing applied to calculate total score as stored in the database.
+        /// If this does not match <see cref="LegacyScoreEncoder.LATEST_VERSION"/>,
+        /// the total score has not yet been updated to reflect the current scoring values.
+        ///
+        /// See <see cref="BackgroundBeatmapProcessor"/>'s conversion logic.
+        /// </summary>
+        /// <remarks>
+        /// This may not match the version stored in the replay files.
+        /// </remarks>
+        internal int TotalScoreVersion { get; set; } = LegacyScoreEncoder.LATEST_VERSION;
+
+        /// <summary>
+        /// Used to preserve the total score for legacy scores.
+        /// </summary>
+        /// <remarks>
+        /// Not populated if <see cref="IsLegacyScore"/> is <c>false</c>.
+        /// </remarks>
+        internal long? LegacyTotalScore { get; set; }
+
         public int MaxCombo { get; set; }
 
         public double Accuracy { get; set; }