add accuracy challenge mod

osu.Game.Rulesets.Catch/CatchRuleset.cs

@@ -109,6 +109,7 @@ namespace osu.Game.Rulesets.Catch
                         new MultiMod(new CatchModDoubleTime(), new CatchModNightcore()),
                         new CatchModHidden(),
                         new CatchModFlashlight(),
+                        //new ModAccuracyChallenge(),
                     };
 
                 case ModType.Conversion:

osu.Game.Rulesets.Mania/ManiaRuleset.cs

@@ -222,6 +222,7 @@ namespace osu.Game.Rulesets.Mania
                         new MultiMod(new ManiaModDoubleTime(), new ManiaModNightcore()),
                         new MultiMod(new ManiaModFadeIn(), new ManiaModHidden()),
                         new ManiaModFlashlight(),
+                        //new ModAccuracyChallenge(),
                     };
 
                 case ModType.Conversion:

osu.Game.Rulesets.Osu/OsuRuleset.cs

@@ -159,7 +159,8 @@ namespace osu.Game.Rulesets.Osu
                         new MultiMod(new OsuModDoubleTime(), new OsuModNightcore()),
                         new OsuModHidden(),
                         new MultiMod(new OsuModFlashlight(), new OsuModBlinds()),
-                        new OsuModStrictTracking()
+                        new OsuModStrictTracking(),
+                        new ModAccuracyChallenge(),
                     };
 
                 case ModType.Conversion:

osu.Game.Rulesets.Taiko/TaikoRuleset.cs

@@ -128,6 +128,7 @@ namespace osu.Game.Rulesets.Taiko
                         new MultiMod(new TaikoModDoubleTime(), new TaikoModNightcore()),
                         new TaikoModHidden(),
                         new TaikoModFlashlight(),
+                        //new ModAccuracyChallenge(),
                     };
 
                 case ModType.Conversion:

osu.Game/Rulesets/Mods/ModAccuracyChallenge.cs

@@ -0,0 +1,59 @@
+// 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.Linq;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics.Sprites;
+using osu.Game.Configuration;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Overlays.Settings;
+using osu.Game.Rulesets.Scoring;
+using osu.Game.Rulesets.Judgements;
+
+namespace osu.Game.Rulesets.Mods
+{
+    public class ModAccuracyChallenge : ModFailCondition
+    {
+        public override string Name => "Accuracy Challenge";
+        public override string Acronym => "AC";
+        public override string Description => "Fail the map if you don't maintain a certain accuracy.";
+        public override IconUsage? Icon => FontAwesome.Solid.Calculator;
+        public override ModType Type => ModType.DifficultyIncrease;
+        public override double ScoreMultiplier => 1.0;
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Append(typeof(ModEasyWithExtraLives)).Append(typeof(ModPerfect)).ToArray();
+
+        [SettingSource("Minimum accuracy", "Trigger a failure if your accuracy goes below this value.", SettingControlType = typeof(SettingsSlider<double, PercentSlider>))]
+        public BindableNumber<double> MinimumAccuracy { get; } = new BindableDouble
+        {
+            MinValue = 0,
+            MaxValue = 1,
+            Precision = 0.01,
+            Default = 0.9,
+            Value = 0.9,
+        };
+
+        private double baseScore;
+        private double maxBaseScore;
+        private double accuracy => maxBaseScore > 0 ? baseScore / maxBaseScore : 1;
+
+        protected override bool FailCondition(HealthProcessor healthProcessor, JudgementResult result)
+        {
+            if (!result.Type.IsScorable() || result.Type.IsBonus())
+                return false;
+
+            baseScore += result.Type.IsHit() ? result.Judgement.NumericResultFor(result) : 0;
+            maxBaseScore += result.Judgement.MaxNumericResult;
+
+            return accuracy < MinimumAccuracy.Value;
+        }
+    }
+
+    public class PercentSlider : OsuSliderBar<double>
+    {
+        public PercentSlider()
+        {
+            DisplayAsPercentage = true;
+        }
+    }
+}

osu.Game/Rulesets/Mods/ModEasyWithExtraLives.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 System;
+using System.Linq;
 using Humanizer;
 using osu.Framework.Bindables;
 using osu.Game.Beatmaps;
@@ -19,6 +21,7 @@ namespace osu.Game.Rulesets.Mods
         };
 
         public override string SettingDescription => Retries.IsDefault ? string.Empty : $"{"lives".ToQuantity(Retries.Value)}";
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Append(typeof(ModAccuracyChallenge)).ToArray();
 
         private int retries;
 

osu.Game/Rulesets/Mods/ModPerfect.cs

@@ -19,7 +19,7 @@ namespace osu.Game.Rulesets.Mods
         public override double ScoreMultiplier => 1;
         public override string Description => "SS or quit.";
 
-        public override Type[] IncompatibleMods => base.IncompatibleMods.Append(typeof(ModSuddenDeath)).ToArray();
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Append(typeof(ModSuddenDeath)).Append(typeof(ModAccuracyChallenge)).ToArray();
 
         protected ModPerfect()
         {