Merge pull request #18263 from frenzibyte/spotlight-beatmap-badge

Add support for "spotlight" label in beatmap overlay/listing
Move badge hierarchy declaration to constructor for safer access
2026-05-19 21:40:34 +08:00 · 2022-05-15 12:32:20 +09:00 · 2022-05-14 21:54:56 +03:00 · 2022-05-14 20:48:42 +02:00 · 2022-05-15 03:25:14 +09:00 · 2022-05-15 03:16:43 +09:00
619 changed files with 13204 additions and 6395 deletions
@@ -2,14 +2,8 @@
  "version": 1,
  "isRoot": true,
  "tools": {
-    "dotnet-format": {
-      "version": "3.1.37601",
-      "commands": [
-        "dotnet-format"
-      ]
-    },
    "jetbrains.resharper.globaltools": {
-      "version": "2020.3.2",
+      "version": "2022.1.1",
      "commands": [
        "jb"
      ]
@@ -27,10 +21,10 @@
      ]
    },
    "ppy.localisationanalyser.tools": {
-      "version": "2022.320.0",
+      "version": "2022.417.0",
      "commands": [
        "localisation"
      ]
    }
  }
-}
+}
@@ -1,6 +1,14 @@
 # EditorConfig is awesome: http://editorconfig.org
 root = true

+[*.{csproj,props,targets}]
+charset = utf-8-bom
+end_of_line = crlf
+insert_final_newline = true
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true
+
 [*.cs]
 end_of_line = crlf
 insert_final_newline = true
@@ -8,8 +16,19 @@ indent_style = space
 indent_size = 4
 trim_trailing_whitespace = true

+#license header
+file_header_template = Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.\nSee the LICENCE file in the repository root for full licence text.
+
 #Roslyn naming styles

+#PascalCase for public and protected members
+dotnet_naming_style.pascalcase.capitalization = pascal_case
+dotnet_naming_symbols.public_members.applicable_accessibilities = public,internal,protected,protected_internal,private_protected
+dotnet_naming_symbols.public_members.applicable_kinds = property,method,field,event
+dotnet_naming_rule.public_members_pascalcase.severity = error
+dotnet_naming_rule.public_members_pascalcase.symbols = public_members
+dotnet_naming_rule.public_members_pascalcase.style = pascalcase
+
 #camelCase for private members
 dotnet_naming_style.camelcase.capitalization = camel_case

@@ -172,23 +191,11 @@ csharp_style_prefer_index_operator = false:silent
 csharp_style_prefer_range_operator = false:silent
 csharp_style_prefer_switch_expression = false:none

-#Supressing roslyn built-in analyzers
-# Suppress: EC112
-
-#Private method is unused
-dotnet_diagnostic.IDE0051.severity = silent
-#Private member is unused
-dotnet_diagnostic.IDE0052.severity = silent
-
-#Rules for disposable
-dotnet_diagnostic.IDE0067.severity = none
-dotnet_diagnostic.IDE0068.severity = none
-dotnet_diagnostic.IDE0069.severity = none
-
-#Disable operator overloads requiring alternate named methods
-dotnet_diagnostic.CA2225.severity = none
-
-# Banned APIs
-dotnet_diagnostic.RS0030.severity = error
+[*.{yaml,yml}]
+insert_final_newline = true
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true

+dotnet_diagnostic.OLOC001.words_in_name = 5
 dotnet_diagnostic.OLOC001.license_header = // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.\n// See the LICENCE file in the repository root for full licence text.
@@ -2,6 +2,59 @@ on: [push, pull_request]
 name: Continuous Integration

 jobs:
+  inspect-code:
+    name: Code Quality
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      # FIXME: Tools won't run in .NET 6.0 unless you install 3.1.x LTS side by side.
+      # https://itnext.io/how-to-support-multiple-net-sdks-in-github-actions-workflows-b988daa884e
+      - name: Install .NET 3.1.x LTS
+        uses: actions/setup-dotnet@v1
+        with:
+          dotnet-version: "3.1.x"
+
+      - name: Install .NET 6.0.x
+        uses: actions/setup-dotnet@v1
+        with:
+          dotnet-version: "6.0.x"
+
+      - name: Restore Tools
+        run: dotnet tool restore
+
+      - name: Restore Packages
+        run: dotnet restore
+
+      - name: Restore inspectcode cache
+        uses: actions/cache@v3
+        with:
+          path: ${{ github.workspace }}/inspectcode
+          key: inspectcode-${{ hashFiles('.config/dotnet-tools.json', '.github/workflows/ci.yml', 'osu.sln*', '.editorconfig', '.globalconfig') }}
+
+      - name: Dotnet code style
+        run: dotnet build -c Debug -warnaserror osu.Desktop.slnf -p:EnforceCodeStyleInBuild=true
+
+      - name: CodeFileSanity
+        run: |
+          # TODO: Add ignore filters and GitHub Workflow Command Reporting in CFS. That way we don't have to do this workaround.
+          # FIXME: Suppress warnings from templates project
+          exit_code=0
+          while read -r line; do
+            if [[ ! -z "$line" ]]; then
+              echo "::error::$line"
+              exit_code=1
+            fi
+          done <<< $(dotnet codefilesanity)
+          exit $exit_code
+
+      - name: InspectCode
+        run: dotnet jb inspectcode $(pwd)/osu.Desktop.slnf --no-build --output="inspectcodereport.xml" --caches-home="inspectcode" --verbosity=WARN
+
+      - name: NVika
+        run: dotnet nvika parsereport "${{github.workspace}}/inspectcodereport.xml" --treatwarningsaserrors
+
  test:
    name: Test
    runs-on: ${{matrix.os.fullname}}
@@ -94,51 +147,3 @@ jobs:
      # Build just the main game for now.
      - name: Build
        run: msbuild osu.iOS/osu.iOS.csproj /restore /p:Configuration=Debug
-
-  inspect-code:
-    name: Code Quality
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v2
-
-      # FIXME: Tools won't run in .NET 6.0 unless you install 3.1.x LTS side by side.
-      # https://itnext.io/how-to-support-multiple-net-sdks-in-github-actions-workflows-b988daa884e
-      - name: Install .NET 3.1.x LTS
-        uses: actions/setup-dotnet@v1
-        with:
-          dotnet-version: "3.1.x"
-
-      - name: Install .NET 6.0.x
-        uses: actions/setup-dotnet@v1
-        with:
-          dotnet-version: "6.0.x"
-
-      - name: Restore Tools
-        run: dotnet tool restore
-
-      - name: Restore Packages
-        run: dotnet restore
-
-      - name: CodeFileSanity
-        run: |
-          # TODO: Add ignore filters and GitHub Workflow Command Reporting in CFS. That way we don't have to do this workaround.
-          # FIXME: Suppress warnings from templates project
-          exit_code=0
-          while read -r line; do
-            if [[ ! -z "$line" ]]; then
-              echo "::error::$line"
-              exit_code=1
-            fi
-          done <<< $(dotnet codefilesanity)
-          exit $exit_code
-
-      # Temporarily disabled due to test failures, but it won't work anyway until the tool is upgraded.
-      # - name: .NET Format (Dry Run)
-      #   run: dotnet format --dry-run --check
-
-      - name: InspectCode
-        run: dotnet jb inspectcode $(pwd)/osu.Desktop.slnf --output=$(pwd)/inspectcodereport.xml --cachesDir=$(pwd)/inspectcode --verbosity=WARN
-
-      - name: NVika
-        run: dotnet nvika parsereport "${{github.workspace}}/inspectcodereport.xml" --treatwarningsaserrors
@@ -0,0 +1,55 @@
+is_global = true
+
+# .NET Code Style
+# IDE styles reference: https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/
+
+# IDE0001: Simplify names
+dotnet_diagnostic.IDE0001.severity = warning
+
+# IDE0002: Simplify member access
+dotnet_diagnostic.IDE0002.severity = warning
+
+# IDE0003: Remove qualification
+dotnet_diagnostic.IDE0003.severity = warning
+
+# IDE0004: Remove unnecessary cast
+dotnet_diagnostic.IDE0004.severity = warning
+
+# IDE0005: Remove unnecessary imports
+dotnet_diagnostic.IDE0005.severity = warning
+
+# IDE0034: Simplify default literal
+dotnet_diagnostic.IDE0034.severity = warning
+
+# IDE0036: Sort modifiers
+dotnet_diagnostic.IDE0036.severity = warning
+
+# IDE0040: Add accessibility modifier
+dotnet_diagnostic.IDE0040.severity = warning
+
+# IDE0049: Use keyword for type name
+dotnet_diagnostic.IDE0040.severity = warning
+
+# IDE0055: Fix formatting
+dotnet_diagnostic.IDE0055.severity = warning
+
+# IDE0051: Private method is unused
+dotnet_diagnostic.IDE0051.severity = silent
+
+# IDE0052: Private member is unused
+dotnet_diagnostic.IDE0052.severity = silent
+
+# IDE0073: File header
+dotnet_diagnostic.IDE0073.severity = warning
+
+# IDE0130: Namespace mismatch with folder
+dotnet_diagnostic.IDE0130.severity = warning
+
+# IDE1006: Naming style
+dotnet_diagnostic.IDE1006.severity = warning
+
+#Disable operator overloads requiring alternate named methods
+dotnet_diagnostic.CA2225.severity = none
+
+# Banned APIs
+dotnet_diagnostic.RS0030.severity = error
@@ -1,5 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="SwUserDefinedSpecifications">
+    <option name="specTypeByUrl">
+      <map />
+    </option>
+  </component>
  <component name="com.jetbrains.rider.android.RiderAndroidMiscFileCreationComponent">
    <option name="ENSURE_MISC_FILE_EXISTS" value="true" />
  </component>
@@ -1,4 +1,4 @@
-<!-- Contains required properties for osu!framework projects. -->
+<!-- Contains required properties for osu!framework projects. -->
 <Project>
  <PropertyGroup Label="C#">
    <LangVersion>8.0</LangVersion>
@@ -26,14 +26,6 @@
    <GenerateDocumentationFile>true</GenerateDocumentationFile>
    <NoWarn>$(NoWarn);CS1591</NoWarn>
  </PropertyGroup>
-  <PropertyGroup Label="Project">
-    <!--
-    NU1701:
-      DeepEqual is not netstandard-compatible. This is fine since we run tests with .NET Framework anyway.
-      This is required due to https://github.com/NuGet/Home/issues/5740
-    -->
-    <NoWarn>$(NoWarn);NU1701</NoWarn>
-  </PropertyGroup>
  <PropertyGroup Label="Nuget">
    <IsPackable>false</IsPackable>
    <Authors>ppy Pty Ltd</Authors>
@@ -42,7 +34,7 @@
    <RepositoryUrl>https://github.com/ppy/osu</RepositoryUrl>
    <PackageReleaseNotes>Automated release.</PackageReleaseNotes>
    <Company>ppy Pty Ltd</Company>
-    <Copyright>Copyright (c) 2021 ppy Pty Ltd</Copyright>
+    <Copyright>Copyright (c) 2022 ppy Pty Ltd</Copyright>
    <PackageTags>osu game</PackageTags>
  </PropertyGroup>
 </Project>
@@ -5,7 +5,7 @@ dotnet tool restore
  # - cmd: dotnet format --dry-run --check

 dotnet CodeFileSanity
-dotnet jb inspectcode "osu.Desktop.slnf" --output="inspectcodereport.xml" --caches-home="inspectcode" --verbosity=WARN
+dotnet jb inspectcode "osu.Desktop.slnf" --no-build --output="inspectcodereport.xml" --caches-home="inspectcode" --verbosity=WARN
 dotnet nvika parsereport "inspectcodereport.xml" --treatwarningsaserrors

 exit $LASTEXITCODE
@@ -2,5 +2,5 @@

 dotnet tool restore
 dotnet CodeFileSanity
-dotnet jb inspectcode "osu.Desktop.slnf" --output="inspectcodereport.xml" --caches-home="inspectcode" --verbosity=WARN
+dotnet jb inspectcode "osu.Desktop.slnf" --no-build --output="inspectcodereport.xml" --caches-home="inspectcode" --verbosity=WARN
 dotnet nvika parsereport "inspectcodereport.xml" --treatwarningsaserrors
@@ -1,4 +1,4 @@
-Copyright (c) 2021 ppy Pty Ltd <contact@ppy.sh>.
+Copyright (c) 2022 ppy Pty Ltd <contact@ppy.sh>.

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -1,5 +1,5 @@
 <p align="center">
-  <img width="500px" src="assets/lazer.png">
+  <img width="500" alt="osu! logo" src="assets/lazer.png">
 </p>

 # osu!
@@ -8,6 +8,7 @@
 [![GitHub release](https://img.shields.io/github/release/ppy/osu.svg)](https://github.com/ppy/osu/releases/latest)
 [![CodeFactor](https://www.codefactor.io/repository/github/ppy/osu/badge)](https://www.codefactor.io/repository/github/ppy/osu)
 [![dev chat](https://discordapp.com/api/guilds/188630481301012481/widget.png?style=shield)](https://discord.gg/ppy)
+[![Crowdin](https://d322cqt584bo4o.cloudfront.net/osu-web/localized.svg)](https://crowdin.com/project/osu-web)

 A free-to-win rhythm game. Rhythm is just a *click* away!

@@ -31,7 +32,7 @@ If you are looking to install or test osu! without setting up a development envi

 **Latest build:**

-| [Windows 8.1+ (x64)](https://github.com/ppy/osu/releases/latest/download/install.exe) | macOS 10.15+ ([Intel](https://github.com/ppy/osu/releases/latest/download/osu.app.Intel.zip), [Apple Silicon](https://github.com/ppy/osu/releases/latest/download/osu.app.Apple.Silicon.zip)) | [Linux (x64)](https://github.com/ppy/osu/releases/latest/download/osu.AppImage) | [iOS 10+](https://osu.ppy.sh/home/testflight) | [Android 5+](https://github.com/ppy/osu/releases/latest/download/sh.ppy.osulazer.apk)
+| [Windows 8.1+ (x64)](https://github.com/ppy/osu/releases/latest/download/install.exe) | macOS 10.15+ ([Intel](https://github.com/ppy/osu/releases/latest/download/osu.app.Intel.zip), [Apple Silicon](https://github.com/ppy/osu/releases/latest/download/osu.app.Apple.Silicon.zip)) | [Linux (x64)](https://github.com/ppy/osu/releases/latest/download/osu.AppImage) | [iOS 10+](https://osu.ppy.sh/home/testflight) | [Android 5+](https://github.com/ppy/osu/releases/latest/download/sh.ppy.osulazer.apk) |
 | ------------- | ------------- | ------------- | ------------- | ------------- |

 - The iOS testflight link may fill up (Apple has a hard limit of 10,000 users). We reset it occasionally when this happens. Please do not ask about this. Check back regularly for link resets or follow [peppy](https://twitter.com/ppy) on twitter for announcements of link resets.
@@ -104,6 +105,8 @@ When it comes to contributing to the project, the two main things you can do to

 Note that while we already have certain standards in place, nothing is set in stone. If you have an issue with the way code is structured, with any libraries we are using, or with any processes involved with contributing, *please* bring it up. We welcome all feedback so we can make contributing to this project as painless as possible.

+If you wish to help with localisation efforts, head over to [crowdin](https://crowdin.com/project/osu-web).
+
 For those interested, we love to reward quality contributions via [bounties](https://docs.google.com/spreadsheets/d/1jNXfj_S3Pb5PErA-czDdC9DUu4IgUbe1Lt8E7CYUJuE/view?&rm=minimal#gid=523803337), paid out via PayPal or osu!supporter tags. Don't hesitate to [request a bounty](https://docs.google.com/forms/d/e/1FAIpQLSet_8iFAgPMG526pBZ2Kic6HSh7XPM3fE8xPcnWNkMzINDdYg/viewform) for your work on this project.

 ## Licence
@@ -11,7 +11,7 @@
  <ItemGroup Label="Package References">
    <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
-    <PackageReference Include="NUnit" Version="3.13.2" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
    <PackageReference Include="NUnit3TestAdapter" Version="4.1.0" />
    <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
  </ItemGroup>
@@ -1,6 +1,7 @@
 // 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;
@@ -25,6 +26,6 @@ namespace osu.Game.Rulesets.EmptyFreeform

        protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();

-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[0];
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => Array.Empty<Skill>();
    }
 }
@@ -11,7 +11,7 @@
  <ItemGroup Label="Package References">
    <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
-    <PackageReference Include="NUnit" Version="3.13.2" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
    <PackageReference Include="NUnit3TestAdapter" Version="4.1.0" />
    <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
  </ItemGroup>
@@ -1,6 +1,7 @@
 // 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;
@@ -25,6 +26,6 @@ namespace osu.Game.Rulesets.Pippidon

        protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();

-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[0];
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => Array.Empty<Skill>();
    }
 }
@@ -11,7 +11,7 @@
  <ItemGroup Label="Package References">
    <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
-    <PackageReference Include="NUnit" Version="3.13.2" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
    <PackageReference Include="NUnit3TestAdapter" Version="4.1.0" />
    <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
  </ItemGroup>
@@ -1,6 +1,7 @@
 // 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;
@@ -25,6 +26,6 @@ namespace osu.Game.Rulesets.EmptyScrolling

        protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();

-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[0];
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => Array.Empty<Skill>();
    }
 }
@@ -11,7 +11,7 @@
  <ItemGroup Label="Package References">
    <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
-    <PackageReference Include="NUnit" Version="3.13.2" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
    <PackageReference Include="NUnit3TestAdapter" Version="4.1.0" />
    <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
  </ItemGroup>
@@ -1,6 +1,7 @@
 // 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;
@@ -25,6 +26,6 @@ namespace osu.Game.Rulesets.Pippidon

        protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(IBeatmap beatmap, double clockRate) => Enumerable.Empty<DifficultyHitObject>();

-        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => new Skill[0];
+        protected override Skill[] CreateSkills(IBeatmap beatmap, Mod[] mods, double clockRate) => Array.Empty<Skill>();
    }
 }
@@ -8,7 +8,7 @@
    <PackageProjectUrl>https://github.com/ppy/osu/blob/master/Templates</PackageProjectUrl>
    <RepositoryUrl>https://github.com/ppy/osu</RepositoryUrl>
    <PackageReleaseNotes>Automated release.</PackageReleaseNotes>
-    <copyright>Copyright (c) 2021 ppy Pty Ltd</copyright>
+    <copyright>Copyright (c) 2022 ppy Pty Ltd</copyright>
    <Description>Templates to use when creating a ruleset for consumption in osu!.</Description>
    <PackageTags>dotnet-new;templates;osu</PackageTags>
    <TargetFramework>netstandard2.1</TargetFramework>
@@ -1,4 +1,4 @@
-<Project>
+<Project>
  <PropertyGroup>
    <LangVersion>8.0</LangVersion>
    <OutputPath>bin\$(Configuration)</OutputPath>
@@ -51,11 +51,11 @@
    <Reference Include="Java.Interop" />
  </ItemGroup>
  <ItemGroup>
-    <PackageReference Include="ppy.osu.Game.Resources" Version="2022.405.0" />
-    <PackageReference Include="ppy.osu.Framework.Android" Version="2022.404.0" />
+    <PackageReference Include="ppy.osu.Game.Resources" Version="2022.513.0" />
+    <PackageReference Include="ppy.osu.Framework.Android" Version="2022.511.0" />
  </ItemGroup>
  <ItemGroup Label="Transitive Dependencies">
    <!-- Realm needs to be directly referenced in all Xamarin projects, as it will not pull in its transitive dependencies otherwise. -->
-    <PackageReference Include="Realm" Version="10.10.0" />
+    <PackageReference Include="Realm" Version="10.12.0" />
  </ItemGroup>
 </Project>
@@ -4,8 +4,6 @@
 using System;
 using System.IO;
 using System.Runtime.Versioning;
-using System.Threading;
-using System.Threading.Tasks;
 using osu.Desktop.LegacyIpc;
 using osu.Framework;
 using osu.Framework.Development;
@@ -63,8 +61,6 @@ namespace osu.Desktop

            using (DesktopGameHost host = Host.GetSuitableDesktopHost(gameName, new HostOptions { BindIPC = true }))
            {
-                host.ExceptionThrown += handleException;
-
                if (!host.IsPrimaryInstance)
                {
                    if (args.Length > 0 && args[0].Contains('.')) // easy way to check for a file import in args
@@ -123,26 +119,13 @@ namespace osu.Desktop
                tools.RemoveUninstallerRegistryEntry();
            }, onEveryRun: (version, tools, firstRun) =>
            {
-                tools.SetProcessAppUserModelId();
+                // While setting the `ProcessAppUserModelId` fixes duplicate icons/shortcuts on the taskbar, it currently
+                // causes the right-click context menu to function incorrectly.
+                //
+                // This may turn out to be non-required after an alternative solution is implemented.
+                // see https://github.com/clowd/Clowd.Squirrel/issues/24
+                // tools.SetProcessAppUserModelId();
            });
        }
-
-        private static int allowableExceptions = DebugUtils.IsDebugBuild ? 0 : 1;
-
-        /// <summary>
-        /// Allow a maximum of one unhandled exception, per second of execution.
-        /// </summary>
-        /// <param name="arg"></param>
-        private static bool handleException(Exception arg)
-        {
-            bool continueExecution = Interlocked.Decrement(ref allowableExceptions) >= 0;
-
-            Logger.Log($"Unhandled exception has been {(continueExecution ? $"allowed with {allowableExceptions} more allowable exceptions" : "denied")} .");
-
-            // restore the stock of allowable exceptions after a short delay.
-            Task.Delay(1000).ContinueWith(_ => Interlocked.Increment(ref allowableExceptions));
-
-            return continueExecution;
-        }
    }
 }
@@ -19,7 +19,7 @@ namespace osu.Desktop.Security
    public class ElevatedPrivilegesChecker : Component
    {
        [Resolved]
-        private NotificationOverlay notifications { get; set; }
+        private INotificationOverlay notifications { get; set; }

        private bool elevated;

@@ -25,7 +25,7 @@ namespace osu.Desktop.Updater
    public class SquirrelUpdateManager : osu.Game.Updater.UpdateManager
    {
        private UpdateManager updateManager;
-        private NotificationOverlay notificationOverlay;
+        private INotificationOverlay notificationOverlay;

        public Task PrepareUpdateAsync() => UpdateManager.RestartAppWhenExited();

@@ -39,9 +39,9 @@ namespace osu.Desktop.Updater
        private readonly SquirrelLogger squirrelLogger = new SquirrelLogger();

        [BackgroundDependencyLoader]
-        private void load(NotificationOverlay notification)
+        private void load(INotificationOverlay notifications)
        {
-            notificationOverlay = notification;
+            notificationOverlay = notifications;

            SquirrelLocator.CurrentMutable.Register(() => squirrelLogger, typeof(ILogger));
        }
@@ -24,8 +24,7 @@
    <ProjectReference Include="..\osu.Game.Rulesets.Taiko\osu.Game.Rulesets.Taiko.csproj" />
  </ItemGroup>
  <ItemGroup Label="Package References">
-    <PackageReference Include="Clowd.Squirrel" Version="2.8.28-pre" />
-    <PackageReference Include="Microsoft.NETCore.Targets" Version="5.0.0" />
+    <PackageReference Include="Clowd.Squirrel" Version="2.9.40" />
    <PackageReference Include="Mono.Posix.NETStandard" Version="1.0.0" />
    <PackageReference Include="System.IO.Packaging" Version="6.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="5.0.14" />
@@ -33,7 +32,6 @@
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
-    <PackageReference Include="Microsoft.Win32.Registry" Version="5.0.0" />
    <PackageReference Include="DiscordRichPresence" Version="1.0.175" />
  </ItemGroup>
  <ItemGroup Label="Resources">
@@ -11,7 +11,7 @@
        <requireLicenseAcceptance>false</requireLicenseAcceptance>
        <description>A free-to-win rhythm game. Rhythm is just a *click* away!</description>
        <releaseNotes>testing</releaseNotes>
-        <copyright>Copyright (c) 2021 ppy Pty Ltd</copyright>
+        <copyright>Copyright (c) 2022 ppy Pty Ltd</copyright>
        <language>en-AU</language>
    </metadata>
    <files>
@@ -8,7 +8,7 @@

  <ItemGroup>
    <PackageReference Include="BenchmarkDotNet" Version="0.13.1" />
-    <PackageReference Include="nunit" Version="3.13.2" />
+    <PackageReference Include="nunit" Version="3.13.3" />
    <PackageReference Include="NUnit3TestAdapter" Version="4.1.0" />
  </ItemGroup>

@@ -29,13 +29,14 @@ namespace osu.Game.Rulesets.Catch.Tests.Editor

        protected CatchSelectionBlueprintTestScene()
        {
-            EditorBeatmap = new EditorBeatmap(new CatchBeatmap
+            var catchBeatmap = new CatchBeatmap
            {
                BeatmapInfo =
                {
                    Ruleset = new CatchRuleset().RulesetInfo,
                }
-            }) { Difficulty = { CircleSize = 0 } };
+            };
+            EditorBeatmap = new EditorBeatmap(catchBeatmap) { Difficulty = { CircleSize = 0 } };
            EditorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint
            {
                BeatLength = 100
@@ -55,7 +55,10 @@ namespace osu.Game.Rulesets.Catch.Tests.Editor

            AddMoveStep(end_time, 0);
            AddClickStep(MouseButton.Left);
+
            AddMoveStep(start_time, 0);
+            AddAssert("duration is positive", () => ((BananaShower)CurrentBlueprint.HitObject).Duration > 0);
+
            AddClickStep(MouseButton.Right);
            AddAssert("start time is correct", () => Precision.AlmostEquals(LastObject.HitObject.StartTime, start_time));
            AddAssert("end time is correct", () => Precision.AlmostEquals(LastObject.HitObject.GetEndTime(), end_time));
@@ -3,7 +3,7 @@
  <ItemGroup Label="Package References">
    <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
-    <PackageReference Include="NUnit" Version="3.13.2" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
    <PackageReference Include="NUnit3TestAdapter" Version="4.1.0" />
    <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
  </ItemGroup>
@@ -5,10 +5,10 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using osu.Game.Beatmaps;
-using osu.Game.Rulesets.Catch.MathUtils;
 using osu.Game.Rulesets.Catch.Objects;
 using osu.Game.Rulesets.Catch.UI;
 using osu.Game.Rulesets.Objects.Types;
+using osu.Game.Utils;

 namespace osu.Game.Rulesets.Catch.Beatmaps
 {
@@ -46,7 +46,7 @@ namespace osu.Game.Rulesets.Catch.Beatmaps

        public void ApplyPositionOffsets(IBeatmap beatmap)
        {
-            var rng = new FastRandom(RNG_SEED);
+            var rng = new LegacyRandom(RNG_SEED);

            float? lastPosition = null;
            double lastStartTime = 0;
@@ -98,7 +98,7 @@ namespace osu.Game.Rulesets.Catch.Beatmaps
            initialiseHyperDash(beatmap);
        }

-        private static void applyHardRockOffset(CatchHitObject hitObject, ref float? lastPosition, ref double lastStartTime, FastRandom rng)
+        private static void applyHardRockOffset(CatchHitObject hitObject, ref float? lastPosition, ref double lastStartTime, LegacyRandom rng)
        {
            float offsetPosition = hitObject.OriginalX;
            double startTime = hitObject.StartTime;
@@ -146,7 +146,7 @@ namespace osu.Game.Rulesets.Catch.Beatmaps
        /// <param name="position">The position which the offset should be applied to.</param>
        /// <param name="maxOffset">The maximum offset, cannot exceed 20px.</param>
        /// <param name="rng">The random number generator.</param>
-        private static void applyRandomOffset(ref float position, double maxOffset, FastRandom rng)
+        private static void applyRandomOffset(ref float position, double maxOffset, LegacyRandom rng)
        {
            bool right = rng.NextBool();
            float rand = Math.Min(20, (float)rng.Next(0, Math.Max(0, maxOffset)));
@@ -1,6 +1,7 @@
 // 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 osu.Framework.Input.Events;
 using osu.Game.Rulesets.Catch.Edit.Blueprints.Components;
 using osu.Game.Rulesets.Catch.Objects;
@@ -13,11 +14,21 @@ namespace osu.Game.Rulesets.Catch.Edit.Blueprints
    {
        private readonly TimeSpanOutline outline;

+        private double placementStartTime;
+        private double placementEndTime;
+
        public BananaShowerPlacementBlueprint()
        {
            InternalChild = outline = new TimeSpanOutline();
        }

+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            BeginPlacement();
+        }
+
        protected override void Update()
        {
            base.Update();
@@ -38,13 +49,6 @@ namespace osu.Game.Rulesets.Catch.Edit.Blueprints
                case PlacementState.Active:
                    if (e.Button != MouseButton.Right) break;

-                    // If the duration is negative, swap the start and the end time to make the duration positive.
-                    if (HitObject.Duration < 0)
-                    {
-                        HitObject.StartTime = HitObject.EndTime;
-                        HitObject.Duration = -HitObject.Duration;
-                    }
-
                    EndPlacement(HitObject.Duration > 0);
                    return true;
            }
@@ -61,13 +65,16 @@ namespace osu.Game.Rulesets.Catch.Edit.Blueprints
            switch (PlacementActive)
            {
                case PlacementState.Waiting:
-                    HitObject.StartTime = time;
+                    placementStartTime = placementEndTime = time;
                    break;

                case PlacementState.Active:
-                    HitObject.EndTime = time;
+                    placementEndTime = time;
                    break;
            }
+
+            HitObject.StartTime = Math.Min(placementStartTime, placementEndTime);
+            HitObject.EndTime = Math.Max(placementStartTime, placementEndTime);
        }
    }
 }
@@ -47,6 +47,8 @@ namespace osu.Game.Rulesets.Catch.Edit.Blueprints
            base.LoadComplete();

            inputManager = GetContainingInputManager();
+
+            BeginPlacement();
        }

        protected override bool OnMouseDown(MouseDownEvent e)
@@ -24,7 +24,7 @@ using osuTK;

 namespace osu.Game.Rulesets.Catch.Edit
 {
-    public class CatchHitObjectComposer : HitObjectComposer<CatchHitObject>
+    public class CatchHitObjectComposer : DistancedHitObjectComposer<CatchHitObject>
    {
        private const float distance_snap_radius = 50;

@@ -42,6 +42,10 @@ namespace osu.Game.Rulesets.Catch.Edit
        [BackgroundDependencyLoader]
        private void load()
        {
+            // todo: enable distance spacing once catch supports applying it to its existing distance snap grid implementation.
+            RightSideToolboxContainer.Alpha = 0;
+            DistanceSpacingMultiplier.Disabled = true;
+
            LayerBelowRuleset.Add(new PlayfieldBorder
            {
                RelativeSizeAxes = Axes.Both,
@@ -85,9 +89,9 @@ namespace osu.Game.Rulesets.Catch.Edit
            new TernaryButton(distanceSnapToggle, "Distance Snap", () => new SpriteIcon { Icon = FontAwesome.Solid.Ruler })
        });

-        public override SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition)
        {
-            var result = base.SnapScreenSpacePositionToValidTime(screenSpacePosition);
+            var result = base.FindSnappedPositionAndTime(screenSpacePosition);
            result.ScreenSpacePosition.X = screenSpacePosition.X;

            if (distanceSnapGrid.IsPresent && distanceSnapGrid.GetSnappedPosition(result.ScreenSpacePosition) is SnapResult snapResult &&
@@ -90,6 +90,9 @@ namespace osu.Game.Rulesets.Catch.Skinning.Legacy
                            return new LegacyHitExplosion();

                        return null;
+
+                    default:
+                        throw new UnsupportedSkinComponentException(component);
                }
            }

@@ -13,7 +13,6 @@ using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Mania.Beatmaps;
 using osu.Game.Rulesets.Mania.Edit;
 using osu.Game.Rulesets.Mania.UI;
-using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.UI;
 using osu.Game.Rulesets.UI.Scrolling;
@@ -98,37 +97,12 @@ namespace osu.Game.Rulesets.Mania.Tests.Editor
            set => InternalChild = value;
        }

-        public override SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition)
        {
            throw new System.NotImplementedException();
        }

-        public override SnapResult SnapScreenSpacePositionToValidPosition(Vector2 screenSpacePosition)
-        {
-            throw new System.NotImplementedException();
-        }
-
-        public override float GetBeatSnapDistanceAt(HitObject referenceObject)
-        {
-            throw new System.NotImplementedException();
-        }
-
-        public override float DurationToDistance(HitObject referenceObject, double duration)
-        {
-            throw new System.NotImplementedException();
-        }
-
-        public override double DistanceToDuration(HitObject referenceObject, float distance)
-        {
-            throw new System.NotImplementedException();
-        }
-
-        public override double GetSnappedDurationFromDistance(HitObject referenceObject, float distance)
-        {
-            throw new System.NotImplementedException();
-        }
-
-        public override float GetSnappedDistanceFromDistance(HitObject referenceObject, float distance)
+        public override SnapResult FindSnappedPosition(Vector2 screenSpacePosition)
        {
            throw new System.NotImplementedException();
        }
@@ -3,7 +3,7 @@
  <ItemGroup Label="Package References">
    <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
-    <PackageReference Include="NUnit" Version="3.13.2" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
    <PackageReference Include="NUnit3TestAdapter" Version="4.1.0" />
    <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
  </ItemGroup>
@@ -11,8 +11,8 @@ using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Mania.Beatmaps.Patterns;
-using osu.Game.Rulesets.Mania.MathUtils;
 using osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy;
+using osu.Game.Utils;
 using osuTK;

 namespace osu.Game.Rulesets.Mania.Beatmaps
@@ -31,7 +31,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
        private readonly int originalTargetColumns;

        // Internal for testing purposes
-        internal FastRandom Random { get; private set; }
+        internal LegacyRandom Random { get; private set; }

        private Pattern lastPattern = new Pattern();

@@ -84,7 +84,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
            IBeatmapDifficultyInfo difficulty = original.Difficulty;

            int seed = (int)MathF.Round(difficulty.DrainRate + difficulty.CircleSize) * 20 + (int)(difficulty.OverallDifficulty * 41.2) + (int)MathF.Round(difficulty.ApproachRate);
-            Random = new FastRandom(seed);
+            Random = new LegacyRandom(seed);

            return base.ConvertBeatmap(original, cancellationToken);
        }
@@ -227,7 +227,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
        /// </summary>
        private class SpecificBeatmapPatternGenerator : Patterns.Legacy.PatternGenerator
        {
-            public SpecificBeatmapPatternGenerator(FastRandom random, HitObject hitObject, ManiaBeatmap beatmap, Pattern previousPattern, IBeatmap originalBeatmap)
+            public SpecificBeatmapPatternGenerator(LegacyRandom random, HitObject hitObject, ManiaBeatmap beatmap, Pattern previousPattern, IBeatmap originalBeatmap)
                : base(random, hitObject, beatmap, previousPattern, originalBeatmap)
            {
            }
@@ -8,12 +8,12 @@ using System.Linq;
 using osu.Framework.Extensions.EnumExtensions;
 using osu.Game.Audio;
 using osu.Game.Beatmaps;
-using osu.Game.Rulesets.Mania.MathUtils;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Beatmaps.ControlPoints;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.Utils;

 namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
 {
@@ -34,7 +34,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy

        private PatternType convertType;

-        public DistanceObjectPatternGenerator(FastRandom random, HitObject hitObject, ManiaBeatmap beatmap, Pattern previousPattern, IBeatmap originalBeatmap)
+        public DistanceObjectPatternGenerator(LegacyRandom random, HitObject hitObject, ManiaBeatmap beatmap, Pattern previousPattern, IBeatmap originalBeatmap)
            : base(random, hitObject, beatmap, previousPattern, originalBeatmap)
        {
            convertType = PatternType.None;
@@ -2,13 +2,13 @@
 // See the LICENCE file in the repository root for full licence text.

 using System.Collections.Generic;
-using osu.Game.Rulesets.Mania.MathUtils;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Types;
 using System.Linq;
 using osu.Game.Audio;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Mania.Objects;
+using osu.Game.Utils;

 namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
 {
@@ -17,7 +17,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
        private readonly int endTime;
        private readonly PatternType convertType;

-        public EndTimeObjectPatternGenerator(FastRandom random, HitObject hitObject, ManiaBeatmap beatmap, Pattern previousPattern, IBeatmap originalBeatmap)
+        public EndTimeObjectPatternGenerator(LegacyRandom random, HitObject hitObject, ManiaBeatmap beatmap, Pattern previousPattern, IBeatmap originalBeatmap)
            : base(random, hitObject, beatmap, previousPattern, originalBeatmap)
        {
            endTime = (int)((HitObject as IHasDuration)?.EndTime ?? 0);
@@ -9,11 +9,11 @@ using osuTK;
 using osu.Game.Audio;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.ControlPoints;
-using osu.Game.Rulesets.Mania.MathUtils;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Framework.Extensions.IEnumerableExtensions;
+using osu.Game.Utils;

 namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
 {
@@ -23,7 +23,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy

        private readonly PatternType convertType;

-        public HitObjectPatternGenerator(FastRandom random, HitObject hitObject, ManiaBeatmap beatmap, Pattern previousPattern, double previousTime, Vector2 previousPosition, double density,
+        public HitObjectPatternGenerator(LegacyRandom random, HitObject hitObject, ManiaBeatmap beatmap, Pattern previousPattern, double previousTime, Vector2 previousPosition, double density,
                                         PatternType lastStair, IBeatmap originalBeatmap)
            : base(random, hitObject, beatmap, previousPattern, originalBeatmap)
        {
@@ -5,8 +5,8 @@ using System;
 using System.Linq;
 using JetBrains.Annotations;
 using osu.Game.Beatmaps;
-using osu.Game.Rulesets.Mania.MathUtils;
 using osu.Game.Rulesets.Objects;
+using osu.Game.Utils;

 namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
 {
@@ -23,14 +23,14 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
        /// <summary>
        /// The random number generator to use.
        /// </summary>
-        protected readonly FastRandom Random;
+        protected readonly LegacyRandom Random;

        /// <summary>
        /// The beatmap which <see cref="HitObject"/> is being converted from.
        /// </summary>
        protected readonly IBeatmap OriginalBeatmap;

-        protected PatternGenerator(FastRandom random, HitObject hitObject, ManiaBeatmap beatmap, Pattern previousPattern, IBeatmap originalBeatmap)
+        protected PatternGenerator(LegacyRandom random, HitObject hitObject, ManiaBeatmap beatmap, Pattern previousPattern, IBeatmap originalBeatmap)
            : base(hitObject, beatmap, previousPattern)
        {
            if (random == null) throw new ArgumentNullException(nameof(random));
@@ -14,6 +14,7 @@ namespace osu.Game.Rulesets.Mania.Difficulty.Skills
    {
        private const double individual_decay_base = 0.125;
        private const double overall_decay_base = 0.30;
+        private const double release_threshold = 24;

        protected override double SkillMultiplier => 1;
        protected override double StrainDecayBase => 1;
@@ -37,31 +38,43 @@ namespace osu.Game.Rulesets.Mania.Difficulty.Skills
            var maniaCurrent = (ManiaDifficultyHitObject)current;
            double endTime = maniaCurrent.EndTime;
            int column = maniaCurrent.BaseObject.Column;
+            double closestEndTime = Math.Abs(endTime - maniaCurrent.LastObject.StartTime); // Lowest value we can assume with the current information

            double holdFactor = 1.0; // Factor to all additional strains in case something else is held
            double holdAddition = 0; // Addition to the current note in case it's a hold and has to be released awkwardly
+            bool isOverlapping = false;

            // Fill up the holdEndTimes array
            for (int i = 0; i < holdEndTimes.Length; ++i)
            {
-                // If there is at least one other overlapping end or note, then we get an addition, buuuuuut...
-                if (Precision.DefinitelyBigger(holdEndTimes[i], maniaCurrent.StartTime, 1) && Precision.DefinitelyBigger(endTime, holdEndTimes[i], 1))
-                    holdAddition = 1.0;
-
-                // ... this addition only is valid if there is _no_ other note with the same ending. Releasing multiple notes at the same time is just as easy as releasing 1
-                if (Precision.AlmostEquals(endTime, holdEndTimes[i], 1))
-                    holdAddition = 0;
+                // The current note is overlapped if a previous note or end is overlapping the current note body
+                isOverlapping |= Precision.DefinitelyBigger(holdEndTimes[i], maniaCurrent.StartTime, 1) && Precision.DefinitelyBigger(endTime, holdEndTimes[i], 1);

                // We give a slight bonus to everything if something is held meanwhile
                if (Precision.DefinitelyBigger(holdEndTimes[i], endTime, 1))
                    holdFactor = 1.25;

+                closestEndTime = Math.Min(closestEndTime, Math.Abs(endTime - holdEndTimes[i]));
+
                // Decay individual strains
                individualStrains[i] = applyDecay(individualStrains[i], current.DeltaTime, individual_decay_base);
            }

            holdEndTimes[column] = endTime;

+            // The hold addition is given if there was an overlap, however it is only valid if there are no other note with a similar ending.
+            // Releasing multiple notes is just as easy as releasing 1. Nerfs the hold addition by half if the closest release is release_threshold away.
+            // holdAddition
+            //     ^
+            // 1.0 + - - - - - -+-----------
+            //     |           /
+            // 0.5 + - - - - -/   Sigmoid Curve
+            //     |         /|
+            // 0.0 +--------+-+---------------> Release Difference / ms
+            //         release_threshold
+            if (isOverlapping)
+                holdAddition = 1 / (1 + Math.Exp(0.5 * (release_threshold - closestEndTime)));
+
            // Increase individual strain in own column
            individualStrains[column] += 2.0 * holdFactor;
            individualStrain = individualStrains[column];
@@ -56,9 +56,9 @@ namespace osu.Game.Rulesets.Mania.Edit
        protected override Playfield PlayfieldAtScreenSpacePosition(Vector2 screenSpacePosition) =>
            Playfield.GetColumnByPosition(screenSpacePosition);

-        public override SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition)
        {
-            var result = base.SnapScreenSpacePositionToValidTime(screenSpacePosition);
+            var result = base.FindSnappedPositionAndTime(screenSpacePosition);

            switch (ScrollingInfo.Direction.Value)
            {
@@ -112,7 +112,7 @@ namespace osu.Game.Rulesets.Mania.Edit
            }
            else
            {
-                var result = SnapScreenSpacePositionToValidTime(inputManager.CurrentState.Mouse.Position);
+                var result = FindSnappedPositionAndTime(inputManager.CurrentState.Mouse.Position);
                if (result.Time is double time)
                    beatSnapGrid.SelectionTimeRange = (time, time);
                else
@@ -1,95 +0,0 @@
-// 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;
-
-namespace osu.Game.Rulesets.Mania.MathUtils
-{
-    /// <summary>
-    /// A PRNG specified in http://heliosphan.org/fastrandom.html.
-    /// </summary>
-    internal class FastRandom
-    {
-        private const double int_to_real = 1.0 / (int.MaxValue + 1.0);
-        private const uint int_mask = 0x7FFFFFFF;
-        private const uint y = 842502087;
-        private const uint z = 3579807591;
-        private const uint w = 273326509;
-
-        internal uint X { get; private set; }
-        internal uint Y { get; private set; } = y;
-        internal uint Z { get; private set; } = z;
-        internal uint W { get; private set; } = w;
-
-        public FastRandom(int seed)
-        {
-            X = (uint)seed;
-        }
-
-        public FastRandom()
-            : this(Environment.TickCount)
-        {
-        }
-
-        /// <summary>
-        /// Generates a random unsigned integer within the range [<see cref="uint.MinValue"/>, <see cref="uint.MaxValue"/>).
-        /// </summary>
-        /// <returns>The random value.</returns>
-        public uint NextUInt()
-        {
-            uint t = X ^ (X << 11);
-            X = Y;
-            Y = Z;
-            Z = W;
-            return W = W ^ (W >> 19) ^ t ^ (t >> 8);
-        }
-
-        /// <summary>
-        /// Generates a random integer value within the range [0, <see cref="int.MaxValue"/>).
-        /// </summary>
-        /// <returns>The random value.</returns>
-        public int Next() => (int)(int_mask & NextUInt());
-
-        /// <summary>
-        /// Generates a random integer value within the range [0, <paramref name="upperBound"/>).
-        /// </summary>
-        /// <param name="upperBound">The upper bound.</param>
-        /// <returns>The random value.</returns>
-        public int Next(int upperBound) => (int)(NextDouble() * upperBound);
-
-        /// <summary>
-        /// Generates a random integer value within the range [<paramref name="lowerBound"/>, <paramref name="upperBound"/>).
-        /// </summary>
-        /// <param name="lowerBound">The lower bound of the range.</param>
-        /// <param name="upperBound">The upper bound of the range.</param>
-        /// <returns>The random value.</returns>
-        public int Next(int lowerBound, int upperBound) => (int)(lowerBound + NextDouble() * (upperBound - lowerBound));
-
-        /// <summary>
-        /// Generates a random double value within the range [0, 1).
-        /// </summary>
-        /// <returns>The random value.</returns>
-        public double NextDouble() => int_to_real * Next();
-
-        private uint bitBuffer;
-        private int bitIndex = 32;
-
-        /// <summary>
-        /// Generates a reandom boolean value. Cached such that a random value is only generated once in every 32 calls.
-        /// </summary>
-        /// <returns>The random value.</returns>
-        public bool NextBool()
-        {
-            if (bitIndex == 32)
-            {
-                bitBuffer = NextUInt();
-                bitIndex = 1;
-
-                return (bitBuffer & 1) == 1;
-            }
-
-            bitIndex++;
-            return ((bitBuffer >>= 1) & 1) == 1;
-        }
-    }
-}
@@ -116,9 +116,10 @@ namespace osu.Game.Rulesets.Mania.Skinning.Legacy

                        case ManiaSkinComponents.StageForeground:
                            return new LegacyStageForeground();
-                    }

-                    break;
+                        default:
+                            throw new UnsupportedSkinComponentException(component);
+                    }
            }

            return base.GetDrawableComponent(component);
@@ -7,11 +7,10 @@ using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
-using osu.Framework.Input.Events;
+using osu.Framework.Input;
 using osu.Framework.Utils;
 using osu.Game.Beatmaps.ControlPoints;
 using osu.Game.Rulesets.Edit;
-using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Osu.Beatmaps;
 using osu.Game.Rulesets.Osu.Edit;
 using osu.Game.Rulesets.Osu.Objects;
@@ -24,19 +23,29 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
 {
    public class TestSceneOsuDistanceSnapGrid : OsuManualInputManagerTestScene
    {
-        private const double beat_length = 100;
+        private const float beat_length = 100;
+
        private static readonly Vector2 grid_position = new Vector2(512, 384);

        [Cached(typeof(EditorBeatmap))]
+        [Cached(typeof(IBeatSnapProvider))]
        private readonly EditorBeatmap editorBeatmap;

+        [Cached]
+        private readonly EditorClock editorClock;
+
        [Cached]
        private readonly BindableBeatDivisor beatDivisor = new BindableBeatDivisor();

-        [Cached(typeof(IPositionSnapProvider))]
-        private readonly SnapProvider snapProvider = new SnapProvider();
+        [Cached(typeof(IDistanceSnapProvider))]
+        private readonly OsuHitObjectComposer snapProvider = new OsuHitObjectComposer(new OsuRuleset())
+        {
+            // Just used for the snap implementation, so let's hide from vision.
+            AlwaysPresent = true,
+            Alpha = 0,
+        };

-        private TestOsuDistanceSnapGrid grid;
+        private OsuDistanceSnapGrid grid;

        public TestSceneOsuDistanceSnapGrid()
        {
@@ -47,14 +56,25 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
                    Ruleset = new OsuRuleset().RulesetInfo
                }
            });
+
+            editorClock = new EditorClock(editorBeatmap);
+
+            base.Content.Children = new Drawable[]
+            {
+                snapProvider,
+                Content
+            };
        }

+        protected override Container<Drawable> Content { get; } = new Container { RelativeSizeAxes = Axes.Both };
+
        [SetUp]
        public void Setup() => Schedule(() =>
        {
            editorBeatmap.Difficulty.SliderMultiplier = 1;
            editorBeatmap.ControlPointInfo.Clear();
            editorBeatmap.ControlPointInfo.Add(0, new TimingControlPoint { BeatLength = beat_length });
+            snapProvider.DistanceSpacingMultiplier.Value = 1;

            Children = new Drawable[]
            {
@@ -63,7 +83,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
                    RelativeSizeAxes = Axes.Both,
                    Colour = Color4.SlateGray
                },
-                grid = new TestOsuDistanceSnapGrid(new HitCircle { Position = grid_position }),
+                grid = new OsuDistanceSnapGrid(new HitCircle { Position = grid_position }),
                new SnappingCursorContainer { GetSnapPosition = v => grid.GetSnappedPosition(grid.ToLocalSpace(v)).position }
            };
        });
@@ -81,25 +101,52 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
            AddStep($"set beat divisor = {divisor}", () => beatDivisor.Value = divisor);
        }

+        [TestCase(1.0f)]
+        [TestCase(2.0f)]
+        [TestCase(0.5f)]
+        public void TestDistanceSpacing(float multiplier)
+        {
+            AddStep($"set distance spacing = {multiplier}", () => snapProvider.DistanceSpacingMultiplier.Value = multiplier);
+        }
+
        [Test]
        public void TestCursorInCentre()
        {
            AddStep("move mouse to centre", () => InputManager.MoveMouseTo(grid.ToScreenSpace(grid_position)));
-            assertSnappedDistance((float)beat_length);
+            assertSnappedDistance(beat_length);
+        }
+
+        [Test]
+        public void TestCursorAlmostInCentre()
+        {
+            AddStep("move mouse to almost centre", () => InputManager.MoveMouseTo(grid.ToScreenSpace(grid_position) + new Vector2(1)));
+            assertSnappedDistance(beat_length);
        }

        [Test]
        public void TestCursorBeforeMovementPoint()
        {
-            AddStep("move mouse to just before movement point", () => InputManager.MoveMouseTo(grid.ToScreenSpace(grid_position + new Vector2((float)beat_length, 0) * 1.49f)));
-            assertSnappedDistance((float)beat_length);
+            AddStep("move mouse to just before movement point", () => InputManager.MoveMouseTo(grid.ToScreenSpace(grid_position + new Vector2(beat_length, 0) * 1.45f)));
+            assertSnappedDistance(beat_length);
        }

        [Test]
        public void TestCursorAfterMovementPoint()
        {
-            AddStep("move mouse to just after movement point", () => InputManager.MoveMouseTo(grid.ToScreenSpace(grid_position + new Vector2((float)beat_length, 0) * 1.51f)));
-            assertSnappedDistance((float)beat_length * 2);
+            AddStep("move mouse to just after movement point", () => InputManager.MoveMouseTo(grid.ToScreenSpace(grid_position + new Vector2(beat_length, 0) * 1.55f)));
+            assertSnappedDistance(beat_length * 2);
+        }
+
+        [TestCase(0.5f, beat_length * 2)]
+        [TestCase(1, beat_length * 2)]
+        [TestCase(1.5f, beat_length * 1.5f)]
+        [TestCase(2f, beat_length * 2)]
+        public void TestDistanceSpacingAdjust(float multiplier, float expectedDistance)
+        {
+            AddStep($"Set distance spacing to {multiplier}", () => snapProvider.DistanceSpacingMultiplier.Value = multiplier);
+            AddStep("move mouse to point", () => InputManager.MoveMouseTo(grid.ToScreenSpace(grid_position + new Vector2(beat_length, 0) * 2)));
+
+            assertSnappedDistance(expectedDistance);
        }

        [Test]
@@ -114,13 +161,13 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
                        RelativeSizeAxes = Axes.Both,
                        Colour = Color4.SlateGray
                    },
-                    grid = new TestOsuDistanceSnapGrid(new HitCircle { Position = grid_position }, new HitCircle { StartTime = 200 }),
+                    grid = new OsuDistanceSnapGrid(new HitCircle { Position = grid_position }, new HitCircle { StartTime = 200 }),
                    new SnappingCursorContainer { GetSnapPosition = v => grid.GetSnappedPosition(grid.ToLocalSpace(v)).position }
                };
            });

-            AddStep("move mouse outside grid", () => InputManager.MoveMouseTo(grid.ToScreenSpace(grid_position + new Vector2((float)beat_length, 0) * 3f)));
-            assertSnappedDistance((float)beat_length * 2);
+            AddStep("move mouse outside grid", () => InputManager.MoveMouseTo(grid.ToScreenSpace(grid_position + new Vector2(beat_length, 0) * 3f)));
+            assertSnappedDistance(beat_length);
        }

        private void assertSnappedDistance(float expectedDistance) => AddAssert($"snap distance = {expectedDistance}", () =>
@@ -136,6 +183,10 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor

            private readonly Drawable cursor;

+            private InputManager inputManager;
+
+            public override bool HandlePositionalInput => true;
+
            public SnappingCursorContainer()
            {
                RelativeSizeAxes = Axes.Both;
@@ -152,49 +203,14 @@ namespace osu.Game.Rulesets.Osu.Tests.Editor
            {
                base.LoadComplete();

-                updatePosition(GetContainingInputManager().CurrentState.Mouse.Position);
+                inputManager = GetContainingInputManager();
            }

-            protected override bool OnMouseMove(MouseMoveEvent e)
+            protected override void Update()
            {
-                base.OnMouseMove(e);
-
-                updatePosition(e.ScreenSpaceMousePosition);
-                return true;
+                base.Update();
+                cursor.Position = GetSnapPosition.Invoke(inputManager.CurrentState.Mouse.Position);
            }
-
-            private void updatePosition(Vector2 screenSpacePosition)
-            {
-                cursor.Position = GetSnapPosition.Invoke(screenSpacePosition);
-            }
-        }
-
-        private class TestOsuDistanceSnapGrid : OsuDistanceSnapGrid
-        {
-            public new float DistanceSpacing => base.DistanceSpacing;
-
-            public TestOsuDistanceSnapGrid(OsuHitObject hitObject, OsuHitObject nextHitObject = null)
-                : base(hitObject, nextHitObject)
-            {
-            }
-        }
-
-        private class SnapProvider : IPositionSnapProvider
-        {
-            public SnapResult SnapScreenSpacePositionToValidPosition(Vector2 screenSpacePosition) =>
-                new SnapResult(screenSpacePosition, null);
-
-            public SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition) => new SnapResult(screenSpacePosition, 0);
-
-            public float GetBeatSnapDistanceAt(HitObject referenceObject) => (float)beat_length;
-
-            public float DurationToDistance(HitObject referenceObject, double duration) => (float)duration;
-
-            public double DistanceToDuration(HitObject referenceObject, float distance) => distance;
-
-            public double GetSnappedDurationFromDistance(HitObject referenceObject, float distance) => 0;
-
-            public float GetSnappedDistanceFromDistance(HitObject referenceObject, float distance) => 0;
        }
    }
 }
@@ -1,114 +0,0 @@
-// 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 NUnit.Framework;
-using osu.Framework.Allocation;
-using osu.Framework.Graphics;
-using osu.Framework.Graphics.Transforms;
-using osu.Framework.Testing;
-using osu.Framework.Utils;
-using osu.Game.Configuration;
-using osu.Game.Rulesets.Objects;
-using osu.Game.Rulesets.Objects.Drawables;
-using osu.Game.Rulesets.Osu.Edit;
-using osu.Game.Rulesets.Osu.Objects;
-using osu.Game.Rulesets.Osu.Objects.Drawables;
-
-namespace osu.Game.Rulesets.Osu.Tests.Editor
-{
-    [TestFixture]
-    public class TestSceneOsuEditorHitAnimations : TestSceneOsuEditor
-    {
-        [Resolved]
-        private OsuConfigManager config { get; set; }
-
-        [Test]
-        public void TestHitCircleAnimationDisable()
-        {
-            HitCircle hitCircle = null;
-            DrawableHitCircle drawableHitCircle = null;
-
-            AddStep("retrieve first hit circle", () => hitCircle = getHitCircle(0));
-            toggleAnimations(true);
-            seekSmoothlyTo(() => hitCircle.StartTime + 10);
-
-            AddStep("retrieve drawable", () => drawableHitCircle = (DrawableHitCircle)getDrawableObjectFor(hitCircle));
-            assertFutureTransforms(() => drawableHitCircle.CirclePiece, true);
-
-            AddStep("retrieve second hit circle", () => hitCircle = getHitCircle(1));
-            toggleAnimations(false);
-            seekSmoothlyTo(() => hitCircle.StartTime + 10);
-
-            AddStep("retrieve drawable", () => drawableHitCircle = (DrawableHitCircle)getDrawableObjectFor(hitCircle));
-            assertFutureTransforms(() => drawableHitCircle.CirclePiece, false);
-            AddAssert("hit circle has longer fade-out applied", () =>
-            {
-                var alphaTransform = drawableHitCircle.Transforms.Last(t => t.TargetMember == nameof(Alpha));
-                return alphaTransform.EndTime - alphaTransform.StartTime == DrawableOsuEditorRuleset.EDITOR_HIT_OBJECT_FADE_OUT_EXTENSION;
-            });
-        }
-
-        [Test]
-        public void TestSliderAnimationDisable()
-        {
-            Slider slider = null;
-            DrawableSlider drawableSlider = null;
-            DrawableSliderRepeat sliderRepeat = null;
-
-            AddStep("retrieve first slider with repeats", () => slider = getSliderWithRepeats(0));
-            toggleAnimations(true);
-            seekSmoothlyTo(() => slider.StartTime + slider.SpanDuration + 10);
-
-            retrieveDrawables();
-            assertFutureTransforms(() => sliderRepeat, true);
-
-            AddStep("retrieve second slider with repeats", () => slider = getSliderWithRepeats(1));
-            toggleAnimations(false);
-            seekSmoothlyTo(() => slider.StartTime + slider.SpanDuration + 10);
-
-            retrieveDrawables();
-            assertFutureTransforms(() => sliderRepeat.Arrow, false);
-            seekSmoothlyTo(() => slider.GetEndTime());
-            AddAssert("slider has longer fade-out applied", () =>
-            {
-                var alphaTransform = drawableSlider.Transforms.Last(t => t.TargetMember == nameof(Alpha));
-                return alphaTransform.EndTime - alphaTransform.StartTime == DrawableOsuEditorRuleset.EDITOR_HIT_OBJECT_FADE_OUT_EXTENSION;
-            });
-
-            void retrieveDrawables() =>
-                AddStep("retrieve drawables", () =>
-                {
-                    drawableSlider = (DrawableSlider)getDrawableObjectFor(slider);
-                    sliderRepeat = (DrawableSliderRepeat)getDrawableObjectFor(slider.NestedHitObjects.OfType<SliderRepeat>().First());
-                });
-        }
-
-        private HitCircle getHitCircle(int index)
-            => EditorBeatmap.HitObjects.OfType<HitCircle>().ElementAt(index);
-
-        private Slider getSliderWithRepeats(int index)
-            => EditorBeatmap.HitObjects.OfType<Slider>().Where(s => s.RepeatCount >= 1).ElementAt(index);
-
-        private DrawableHitObject getDrawableObjectFor(HitObject hitObject)
-            => this.ChildrenOfType<DrawableHitObject>().Single(ho => ho.HitObject == hitObject);
-
-        private IEnumerable<Transform> getTransformsRecursively(Drawable drawable)
-            => drawable.ChildrenOfType<Drawable>().SelectMany(d => d.Transforms);
-
-        private void toggleAnimations(bool enabled)
-            => AddStep($"toggle animations {(enabled ? "on" : "off")}", () => config.SetValue(OsuSetting.EditorHitAnimations, enabled));
-
-        private void seekSmoothlyTo(Func<double> targetTime)
-        {
-            AddStep("seek smoothly", () => EditorClock.SeekSmoothlyTo(targetTime.Invoke()));
-            AddUntilStep("wait for seek", () => Precision.AlmostEquals(targetTime.Invoke(), EditorClock.CurrentTime));
-        }
-
-        private void assertFutureTransforms(Func<Drawable> getDrawable, bool hasFutureTransforms)
-            => AddAssert($"object {(hasFutureTransforms ? "has" : "has no")} future transforms",
-                () => getTransformsRecursively(getDrawable()).Any(t => t.EndTime >= EditorClock.CurrentTime) == hasFutureTransforms);
-    }
-}
@@ -0,0 +1,108 @@
+// 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.
+
+#nullable enable
+
+using System;
+using System.Diagnostics;
+using System.Linq;
+using Moq;
+using NUnit.Framework;
+using osu.Framework.Graphics.OpenGL.Textures;
+using osu.Framework.Graphics.Sprites;
+using osu.Framework.Graphics.Textures;
+using osu.Framework.Testing;
+using osu.Game.Rulesets.Osu.Skinning.Legacy;
+using osu.Game.Skinning;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Rulesets.Osu.Tests
+{
+    [HeadlessTest]
+    public class LegacyMainCirclePieceTest : OsuTestScene
+    {
+        private static readonly object?[][] texture_priority_cases =
+        {
+            // default priority lookup
+            new object?[]
+            {
+                // available textures
+                new[] { @"hitcircle", @"hitcircleoverlay" },
+                // priority lookup prefix
+                null,
+                // expected circle and overlay
+                @"hitcircle", @"hitcircleoverlay",
+            },
+            // custom priority lookup
+            new object?[]
+            {
+                new[] { @"hitcircle", @"hitcircleoverlay", @"sliderstartcircle", @"sliderstartcircleoverlay" },
+                @"sliderstartcircle",
+                @"sliderstartcircle", @"sliderstartcircleoverlay",
+            },
+            // when no sprites are available for the specified prefix, fall back to "hitcircle"/"hitcircleoverlay".
+            new object?[]
+            {
+                new[] { @"hitcircle", @"hitcircleoverlay" },
+                @"sliderstartcircle",
+                @"hitcircle", @"hitcircleoverlay",
+            },
+            // when a circle is available for the specified prefix but no overlay exists, no overlay is displayed.
+            new object?[]
+            {
+                new[] { @"hitcircle", @"hitcircleoverlay", @"sliderstartcircle" },
+                @"sliderstartcircle",
+                @"sliderstartcircle", null
+            },
+            // when no circle is available for the specified prefix but an overlay exists, the overlay is ignored.
+            new object?[]
+            {
+                new[] { @"hitcircle", @"hitcircleoverlay", @"sliderstartcircleoverlay" },
+                @"sliderstartcircle",
+                @"hitcircle", @"hitcircleoverlay",
+            }
+        };
+
+        [TestCaseSource(nameof(texture_priority_cases))]
+        public void TestTexturePriorities(string[] textureFilenames, string priorityLookup, string? expectedCircle, string? expectedOverlay)
+        {
+            TestLegacyMainCirclePiece piece = null!;
+
+            AddStep("load circle piece", () =>
+            {
+                var skin = new Mock<ISkinSource>();
+
+                // shouldn't be required as GetTexture(string) calls GetTexture(string, WrapMode, WrapMode) by default,
+                // but moq doesn't handle that well, therefore explicitly requiring to use `CallBase`:
+                // https://github.com/moq/moq4/issues/972
+                skin.Setup(s => s.GetTexture(It.IsAny<string>())).CallBase();
+
+                skin.Setup(s => s.GetTexture(It.IsIn(textureFilenames), It.IsAny<WrapMode>(), It.IsAny<WrapMode>()))
+                    .Returns((string componentName, WrapMode _, WrapMode __) => new Texture(1, 1) { AssetName = componentName });
+
+                Child = new DependencyProvidingContainer
+                {
+                    CachedDependencies = new (Type, object)[] { (typeof(ISkinSource), skin.Object) },
+                    Child = piece = new TestLegacyMainCirclePiece(priorityLookup),
+                };
+
+                var sprites = this.ChildrenOfType<Sprite>().Where(s => s.Texture.AssetName != null).DistinctBy(s => s.Texture.AssetName).ToArray();
+                Debug.Assert(sprites.Length <= 2);
+            });
+
+            AddAssert("check circle sprite", () => piece.CircleSprite?.Texture?.AssetName == expectedCircle);
+            AddAssert("check overlay sprite", () => piece.OverlaySprite?.Texture?.AssetName == expectedOverlay);
+        }
+
+        private class TestLegacyMainCirclePiece : LegacyMainCirclePiece
+        {
+            public new Sprite? CircleSprite => base.CircleSprite.ChildrenOfType<Sprite>().DistinctBy(s => s.Texture.AssetName).SingleOrDefault();
+            public new Sprite? OverlaySprite => base.OverlaySprite.ChildrenOfType<Sprite>().DistinctBy(s => s.Texture.AssetName).SingleOrDefault();
+
+            public TestLegacyMainCirclePiece(string? priorityLookupPrefix)
+                : base(priorityLookupPrefix, false)
+            {
+            }
+        }
+    }
+}
@@ -16,31 +16,6 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
 {
    public class TestSceneOsuModAlternate : OsuModTestScene
    {
-        [Test]
-        public void TestInputAtIntro() => CreateModTest(new ModTestData
-        {
-            Mod = new OsuModAlternate(),
-            PassCondition = () => Player.ScoreProcessor.Combo.Value == 1,
-            Autoplay = false,
-            Beatmap = new Beatmap
-            {
-                HitObjects = new List<HitObject>
-                {
-                    new HitCircle
-                    {
-                        StartTime = 1000,
-                        Position = new Vector2(100),
-                    },
-                },
-            },
-            ReplayFrames = new List<ReplayFrame>
-            {
-                new OsuReplayFrame(500, new Vector2(200), OsuAction.LeftButton),
-                new OsuReplayFrame(501, new Vector2(200)),
-                new OsuReplayFrame(1000, new Vector2(100), OsuAction.LeftButton),
-            }
-        });
-
        [Test]
        public void TestInputAlternating() => CreateModTest(new ModTestData
        {
@@ -116,17 +91,50 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
            }
        });

+        /// <summary>
+        /// Ensures alternation is reset before the first hitobject after intro.
+        /// </summary>
+        [Test]
+        public void TestInputSingularAtIntro() => CreateModTest(new ModTestData
+        {
+            Mod = new OsuModAlternate(),
+            PassCondition = () => Player.ScoreProcessor.Combo.Value == 1,
+            Autoplay = false,
+            Beatmap = new Beatmap
+            {
+                HitObjects = new List<HitObject>
+                {
+                    new HitCircle
+                    {
+                        StartTime = 1000,
+                        Position = new Vector2(100),
+                    },
+                },
+            },
+            ReplayFrames = new List<ReplayFrame>
+            {
+                // first press during intro.
+                new OsuReplayFrame(500, new Vector2(200), OsuAction.LeftButton),
+                new OsuReplayFrame(501, new Vector2(200)),
+                // press same key at hitobject and ensure it has been hit.
+                new OsuReplayFrame(1000, new Vector2(100), OsuAction.LeftButton),
+            }
+        });
+
+        /// <summary>
+        /// Ensures alternation is reset before the first hitobject after a break.
+        /// </summary>
        [Test]
        public void TestInputSingularWithBreak() => CreateModTest(new ModTestData
        {
            Mod = new OsuModAlternate(),
-            PassCondition = () => Player.ScoreProcessor.Combo.Value == 2,
+            PassCondition = () => Player.ScoreProcessor.Combo.Value == 0 && Player.ScoreProcessor.HighestCombo.Value == 2,
            Autoplay = false,
            Beatmap = new Beatmap
            {
                Breaks = new List<BreakPeriod>
                {
-                    new BreakPeriod(500, 2250),
+                    new BreakPeriod(500, 2000),
                },
                HitObjects = new List<HitObject>
                {
@@ -138,16 +146,29 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
                    new HitCircle
                    {
                        StartTime = 2500,
-                        Position = new Vector2(100),
-                    }
+                        Position = new Vector2(500, 100),
+                    },
+                    new HitCircle
+                    {
+                        StartTime = 3000,
+                        Position = new Vector2(500, 100),
+                    },
                }
            },
            ReplayFrames = new List<ReplayFrame>
            {
+                // first press to start alternate lock.
                new OsuReplayFrame(500, new Vector2(100), OsuAction.LeftButton),
                new OsuReplayFrame(501, new Vector2(100)),
-                new OsuReplayFrame(2500, new Vector2(100), OsuAction.LeftButton),
-                new OsuReplayFrame(2501, new Vector2(100)),
+                // press same key after break but before hit object.
+                new OsuReplayFrame(2250, new Vector2(300, 100), OsuAction.LeftButton),
+                new OsuReplayFrame(2251, new Vector2(300, 100)),
+                // press same key at second hitobject and ensure it has been hit.
+                new OsuReplayFrame(2500, new Vector2(500, 100), OsuAction.LeftButton),
+                new OsuReplayFrame(2501, new Vector2(500, 100)),
+                // press same key at third hitobject and ensure it has been missed.
+                new OsuReplayFrame(3000, new Vector2(500, 100), OsuAction.LeftButton),
+                new OsuReplayFrame(3001, new Vector2(500, 100)),
            }
        });
    }
@@ -70,7 +70,9 @@ namespace osu.Game.Rulesets.Osu.Tests
                var tintingSkin = skinManager.GetSkin(DefaultLegacySkin.CreateInfo());
                tintingSkin.Configuration.ConfigDictionary["AllowSliderBallTint"] = "1";

-                Child = new SkinProvidingContainer(tintingSkin)
+                var provider = Ruleset.Value.CreateInstance().CreateLegacySkinProvider(tintingSkin, Beatmap.Value.Beatmap);
+
+                Child = new SkinProvidingContainer(provider)
                {
                    RelativeSizeAxes = Axes.Both,
                    Child = dho = new DrawableSlider(prepareObject(new Slider
@@ -4,7 +4,7 @@
    <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
    <PackageReference Include="Moq" Version="4.17.2" />
-    <PackageReference Include="NUnit" Version="3.13.2" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
    <PackageReference Include="NUnit3TestAdapter" Version="4.1.0" />
    <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
  </ItemGroup>
@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using osu.Game.Beatmaps;
+using osu.Game.Resources.Localisation.Web;
 using osu.Game.Rulesets.Osu.Objects;

 namespace osu.Game.Rulesets.Osu.Beatmaps
@@ -20,13 +21,13 @@ namespace osu.Game.Rulesets.Osu.Beatmaps
            {
                new BeatmapStatistic
                {
-                    Name = @"Circle Count",
+                    Name = BeatmapsetsStrings.ShowStatsCountCircles,
                    Content = circles.ToString(),
                    CreateIcon = () => new BeatmapStatisticIcon(BeatmapStatisticsIconType.Circles),
                },
                new BeatmapStatistic
                {
-                    Name = @"Slider Count",
+                    Name = BeatmapsetsStrings.ShowStatsCountSliders,
                    Content = sliders.ToString(),
                    CreateIcon = () => new BeatmapStatisticIcon(BeatmapStatisticsIconType.Sliders),
                },
@@ -122,6 +122,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty
            new OsuModEasy(),
            new OsuModHardRock(),
            new OsuModFlashlight(),
+            new MultiMod(new OsuModFlashlight(), new OsuModHidden())
        };
    }
 }
@@ -219,9 +219,6 @@ namespace osu.Game.Rulesets.Osu.Difficulty

            double flashlightValue = Math.Pow(rawFlashlight, 2.0) * 25.0;

-            if (score.Mods.Any(h => h is OsuModHidden))
-                flashlightValue *= 1.3;
-
            // Penalize misses by assessing # of misses relative to the total # of objects. Default a 3% reduction for any # of misses.
            if (effectiveMissCount > 0)
                flashlightValue *= 0.97 * Math.Pow(1 - Math.Pow(effectiveMissCount / totalHits, 0.775), Math.Pow(effectiveMissCount, .875));
@@ -4,6 +4,7 @@
 using System;
 using osu.Game.Rulesets.Difficulty.Preprocessing;
 using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Osu.Mods;
 using osu.Game.Rulesets.Osu.Objects;
 using osuTK;

@@ -85,6 +86,35 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
            setDistances(clockRate);
        }

+        public double OpacityAt(double time, bool hidden)
+        {
+            if (time > BaseObject.StartTime)
+            {
+                // Consider a hitobject as being invisible when its start time is passed.
+                // In reality the hitobject will be visible beyond its start time up until its hittable window has passed,
+                // but this is an approximation and such a case is unlikely to be hit where this function is used.
+                return 0.0;
+            }
+
+            double fadeInStartTime = BaseObject.StartTime - BaseObject.TimePreempt;
+            double fadeInDuration = BaseObject.TimeFadeIn;
+
+            if (hidden)
+            {
+                // Taken from OsuModHidden.
+                double fadeOutStartTime = BaseObject.StartTime - BaseObject.TimePreempt + BaseObject.TimeFadeIn;
+                double fadeOutDuration = BaseObject.TimePreempt * OsuModHidden.FADE_OUT_DURATION_MULTIPLIER;
+
+                return Math.Min
+                (
+                    Math.Clamp((time - fadeInStartTime) / fadeInDuration, 0.0, 1.0),
+                    1.0 - Math.Clamp((time - fadeOutStartTime) / fadeOutDuration, 0.0, 1.0)
+                );
+            }
+
+            return Math.Clamp((time - fadeInStartTime) / fadeInDuration, 0.0, 1.0);
+        }
+
        private void setDistances(double clockRate)
        {
            if (BaseObject is Slider currentSlider)
@@ -2,8 +2,10 @@
 // See the LICENCE file in the repository root for full licence text.

 using System;
+using System.Linq;
 using osu.Game.Rulesets.Difficulty.Preprocessing;
 using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Osu.Mods;
 using osu.Game.Rulesets.Osu.Difficulty.Preprocessing;
 using osu.Game.Rulesets.Osu.Objects;

@@ -17,13 +19,19 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
        public Flashlight(Mod[] mods)
            : base(mods)
        {
+            hidden = mods.Any(m => m is OsuModHidden);
        }

-        private double skillMultiplier => 0.07;
+        private double skillMultiplier => 0.05;
        private double strainDecayBase => 0.15;
        protected override double DecayWeight => 1.0;
        protected override int HistoryLength => 10; // Look back for 10 notes is added for the sake of flashlight calculations.

+        private readonly bool hidden;
+
+        private const double max_opacity_bonus = 0.4;
+        private const double hidden_bonus = 0.2;
+
        private double currentStrain;

        private double strainValueOf(DifficultyHitObject current)
@@ -61,13 +69,22 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
                    // We also want to nerf stacks so that only the first object of the stack is accounted for.
                    double stackNerf = Math.Min(1.0, (currentObj.LazyJumpDistance / scalingFactor) / 25.0);

-                    result += stackNerf * scalingFactor * jumpDistance / cumulativeStrainTime;
+                    // Bonus based on how visible the object is.
+                    double opacityBonus = 1.0 + max_opacity_bonus * (1.0 - osuCurrent.OpacityAt(currentHitObject.StartTime, hidden));
+
+                    result += stackNerf * opacityBonus * scalingFactor * jumpDistance / cumulativeStrainTime;
                }

                lastObj = currentObj;
            }

-            return Math.Pow(smallDistNerf * result, 2.0);
+            result = Math.Pow(smallDistNerf * result, 2.0);
+
+            // Additional bonus for Hidden due to there being no approach circles.
+            if (hidden)
+                result *= 1.0 + hidden_bonus;
+
+            return result;
        }

        private double strainDecay(double ms) => Math.Pow(strainDecayBase, ms / 1000);
@@ -38,7 +38,11 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
            double difficulty = 0;
            double weight = 1;

-            List<double> strains = GetCurrentStrainPeaks().OrderByDescending(d => d).ToList();
+            // Sections with 0 strain are excluded to avoid worst-case time complexity of the following sort (e.g. /b/2351871).
+            // These sections will not contribute to the difficulty.
+            var peaks = GetCurrentStrainPeaks().Where(p => p > 0);
+
+            List<double> strains = peaks.OrderByDescending(d => d).ToList();

            // We are reducing the highest strains first to account for extreme difficulty spikes
            for (int i = 0; i < Math.Min(strains.Count, ReducedSectionCount); i++)
@@ -0,0 +1,86 @@
+// 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.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Utils;
+using osu.Game.Rulesets.Objects.Types;
+using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Rulesets.Osu.Skinning.Default;
+using osu.Game.Screens.Edit;
+using osu.Game.Skinning;
+using osuTK;
+using osuTK.Graphics;
+
+namespace osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles.Components
+{
+    public class HitCircleOverlapMarker : BlueprintPiece<HitCircle>
+    {
+        /// <summary>
+        /// Hit objects are intentionally made to fade out at a constant slower rate than in gameplay.
+        /// This allows a mapper to gain better historical context and use recent hitobjects as reference / snap points.
+        /// </summary>
+        public const double FADE_OUT_EXTENSION = 700;
+
+        private readonly RingPiece ring;
+
+        [Resolved]
+        private EditorClock editorClock { get; set; }
+
+        public HitCircleOverlapMarker()
+        {
+            Origin = Anchor.Centre;
+
+            Size = new Vector2(OsuHitObject.OBJECT_RADIUS * 2);
+
+            InternalChildren = new Drawable[]
+            {
+                new Circle
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    RelativeSizeAxes = Axes.Both,
+                    Colour = Color4.White,
+                },
+                ring = new RingPiece
+                {
+                    BorderThickness = 4,
+                }
+            };
+        }
+
+        [Resolved]
+        private ISkinSource skin { get; set; }
+
+        public override void UpdateFrom(HitCircle hitObject)
+        {
+            base.UpdateFrom(hitObject);
+
+            Scale = new Vector2(hitObject.Scale);
+
+            if (hitObject is IHasComboInformation combo)
+                ring.BorderColour = combo.GetComboColour(skin);
+
+            double editorTime = editorClock.CurrentTime;
+            double hitObjectTime = hitObject.StartTime;
+            bool hasReachedObject = editorTime >= hitObjectTime;
+
+            if (hasReachedObject)
+            {
+                float alpha = Interpolation.ValueAt(editorTime, 0, 1f, hitObjectTime, hitObjectTime + FADE_OUT_EXTENSION, Easing.In);
+                float ringScale = MathHelper.Clamp(Interpolation.ValueAt(editorTime, 0, 1f, hitObjectTime, hitObjectTime + FADE_OUT_EXTENSION / 2, Easing.OutQuint), 0, 1);
+
+                ring.Scale = new Vector2(1 + 0.1f * ringScale);
+                Alpha = 0.9f * (1 - alpha);
+            }
+            else
+                Alpha = 0;
+        }
+
+        public override void Hide()
+        {
+            // intentional no op so we are not hidden when not selected.
+        }
+    }
+}
@@ -1,6 +1,7 @@
 // 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.Framework.Graphics;
 using osu.Framework.Graphics.Primitives;
 using osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles.Components;
 using osu.Game.Rulesets.Osu.Objects;
@@ -14,11 +15,16 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles
        protected new DrawableHitCircle DrawableObject => (DrawableHitCircle)base.DrawableObject;

        protected readonly HitCirclePiece CirclePiece;
+        private readonly HitCircleOverlapMarker marker;

        public HitCircleSelectionBlueprint(HitCircle circle)
            : base(circle)
        {
-            InternalChild = CirclePiece = new HitCirclePiece();
+            InternalChildren = new Drawable[]
+            {
+                marker = new HitCircleOverlapMarker(),
+                CirclePiece = new HitCirclePiece(),
+            };
        }

        protected override void Update()
@@ -26,6 +32,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles
            base.Update();

            CirclePiece.UpdateFrom(HitObject);
+            marker.UpdateFrom(HitObject);
        }

        public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => DrawableObject.HitArea.ReceivePositionalInputAt(screenSpacePos);
@@ -1,19 +1,29 @@
 // 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.Framework.Allocation;
 using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles.Components;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Rulesets.Osu.Objects.Drawables;
+using osu.Game.Screens.Edit;

 namespace osu.Game.Rulesets.Osu.Edit.Blueprints
 {
    public abstract class OsuSelectionBlueprint<T> : HitObjectSelectionBlueprint<T>
        where T : OsuHitObject
    {
+        [Resolved]
+        private EditorClock editorClock { get; set; }
+
        protected new DrawableOsuHitObject DrawableObject => (DrawableOsuHitObject)base.DrawableObject;

        protected override bool AlwaysShowWhenSelected => true;

+        protected override bool ShouldBeAlive => base.ShouldBeAlive
+                                                 || (editorClock.CurrentTime >= Item.StartTime && editorClock.CurrentTime - Item.GetEndTime() < HitCircleOverlapMarker.FADE_OUT_EXTENSION);
+
        protected OsuSelectionBlueprint(T hitObject)
            : base(hitObject)
        {
@@ -43,7 +43,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
        public Action<List<PathControlPoint>> RemoveControlPointsRequested;

        [Resolved(CanBeNull = true)]
-        private IPositionSnapProvider snapProvider { get; set; }
+        private IDistanceSnapProvider snapProvider { get; set; }

        public PathControlPointVisualiser(Slider slider, bool allowSelection)
        {
@@ -255,7 +255,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
            {
                // Special handling for selections containing head control point - the position of the slider changes which means the snapped position and time have to be taken into account
                Vector2 newHeadPosition = Parent.ToScreenSpace(e.MousePosition + (dragStartPositions[0] - dragStartPositions[draggedControlPointIndex]));
-                var result = snapProvider?.SnapScreenSpacePositionToValidTime(newHeadPosition);
+                var result = snapProvider?.FindSnappedPositionAndTime(newHeadPosition);

                Vector2 movementDelta = Parent.ToLocalSpace(result?.ScreenSpacePosition ?? newHeadPosition) - slider.Position;

@@ -1,6 +1,7 @@
 // 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.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Game.Rulesets.Osu.Edit.Blueprints.HitCircles.Components;
 using osu.Game.Rulesets.Osu.Objects;
@@ -13,20 +14,38 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders

        private readonly Slider slider;
        private readonly SliderPosition position;
+        private readonly HitCircleOverlapMarker marker;

        public SliderCircleOverlay(Slider slider, SliderPosition position)
        {
            this.slider = slider;
            this.position = position;

-            InternalChild = CirclePiece = new HitCirclePiece();
+            InternalChildren = new Drawable[]
+            {
+                marker = new HitCircleOverlapMarker(),
+                CirclePiece = new HitCirclePiece(),
+            };
        }

        protected override void Update()
        {
            base.Update();

-            CirclePiece.UpdateFrom(position == SliderPosition.Start ? (HitCircle)slider.HeadCircle : slider.TailCircle);
+            var circle = position == SliderPosition.Start ? (HitCircle)slider.HeadCircle : slider.TailCircle;
+
+            CirclePiece.UpdateFrom(circle);
+            marker.UpdateFrom(circle);
+        }
+
+        public override void Hide()
+        {
+            CirclePiece.Hide();
+        }
+
+        public override void Show()
+        {
+            CirclePiece.Show();
        }
    }
 }
@@ -37,7 +37,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
        private int currentSegmentLength;

        [Resolved(CanBeNull = true)]
-        private HitObjectComposer composer { get; set; }
+        private IDistanceSnapProvider snapProvider { get; set; }

        public SliderPlacementBlueprint()
            : base(new Objects.Slider())
@@ -220,7 +220,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders

        private void updateSlider()
        {
-            HitObject.Path.ExpectedDistance.Value = composer?.GetSnappedDistanceFromDistance(HitObject, (float)HitObject.Path.CalculatedDistance) ?? (float)HitObject.Path.CalculatedDistance;
+            HitObject.Path.ExpectedDistance.Value = snapProvider?.FindSnappedDistance(HitObject, (float)HitObject.Path.CalculatedDistance) ?? (float)HitObject.Path.CalculatedDistance;

            bodyPiece.UpdateFrom(HitObject);
            headCirclePiece.UpdateFrom(HitObject.HeadCircle);
@@ -38,7 +38,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
        protected PathControlPointVisualiser ControlPointVisualiser { get; private set; }

        [Resolved(CanBeNull = true)]
-        private HitObjectComposer composer { get; set; }
+        private IDistanceSnapProvider snapProvider { get; set; }

        [Resolved(CanBeNull = true)]
        private IPlacementHandler placementHandler { get; set; }
@@ -208,7 +208,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
            // Move the control points from the insertion index onwards to make room for the insertion
            controlPoints.Insert(insertionIndex, pathControlPoint);

-            HitObject.SnapTo(composer);
+            HitObject.SnapTo(snapProvider);

            return pathControlPoint;
        }
@@ -230,7 +230,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders
            }

            // Snap the slider to the current beat divisor before checking length validity.
-            HitObject.SnapTo(composer);
+            HitObject.SnapTo(snapProvider);

            // If there are 0 or 1 remaining control points, or the slider has an invalid length, it is in a degenerate form and should be deleted
            if (controlPoints.Count <= 1 || !HitObject.Path.HasValidLength)
@@ -2,16 +2,8 @@
 // See the LICENCE file in the repository root for full licence text.

 using System.Collections.Generic;
-using System.Linq;
-using osu.Framework.Allocation;
-using osu.Framework.Bindables;
-using osu.Framework.Graphics;
 using osu.Game.Beatmaps;
-using osu.Game.Configuration;
 using osu.Game.Rulesets.Mods;
-using osu.Game.Rulesets.Objects.Drawables;
-using osu.Game.Rulesets.Osu.Objects.Drawables;
-using osu.Game.Rulesets.Osu.Skinning.Default;
 using osu.Game.Rulesets.Osu.UI;
 using osu.Game.Rulesets.UI;
 using osuTK;
@@ -20,12 +12,6 @@ namespace osu.Game.Rulesets.Osu.Edit
 {
    public class DrawableOsuEditorRuleset : DrawableOsuRuleset
    {
-        /// <summary>
-        /// Hit objects are intentionally made to fade out at a constant slower rate than in gameplay.
-        /// This allows a mapper to gain better historical context and use recent hitobjects as reference / snap points.
-        /// </summary>
-        public const double EDITOR_HIT_OBJECT_FADE_OUT_EXTENSION = 700;
-
        public DrawableOsuEditorRuleset(Ruleset ruleset, IBeatmap beatmap, IReadOnlyList<Mod> mods)
            : base(ruleset, beatmap, mods)
        {
@@ -37,80 +23,12 @@ namespace osu.Game.Rulesets.Osu.Edit

        private class OsuEditorPlayfield : OsuPlayfield
        {
-            private Bindable<bool> hitAnimations;
-
            protected override GameplayCursorContainer CreateCursor() => null;

            public OsuEditorPlayfield()
            {
                HitPolicy = new AnyOrderHitPolicy();
            }
-
-            [BackgroundDependencyLoader]
-            private void load(OsuConfigManager config)
-            {
-                hitAnimations = config.GetBindable<bool>(OsuSetting.EditorHitAnimations);
-            }
-
-            protected override void OnNewDrawableHitObject(DrawableHitObject d)
-            {
-                d.ApplyCustomUpdateState += updateState;
-            }
-
-            private void updateState(DrawableHitObject hitObject, ArmedState state)
-            {
-                if (state == ArmedState.Idle || hitAnimations.Value)
-                    return;
-
-                if (hitObject is DrawableHitCircle circle)
-                {
-                    using (circle.BeginAbsoluteSequence(circle.HitStateUpdateTime))
-                    {
-                        circle.ApproachCircle
-                              .FadeOutFromOne(EDITOR_HIT_OBJECT_FADE_OUT_EXTENSION * 4)
-                              .Expire();
-
-                        circle.ApproachCircle.ScaleTo(1.1f, 300, Easing.OutQuint);
-                    }
-                }
-
-                if (hitObject is IHasMainCirclePiece mainPieceContainer)
-                {
-                    // clear any explode animation logic.
-                    // this is scheduled after children to ensure that the clear happens after invocations of ApplyCustomUpdateState on the circle piece's nested skinnables.
-                    ScheduleAfterChildren(() =>
-                    {
-                        if (hitObject.HitObject == null) return;
-
-                        mainPieceContainer.CirclePiece.ApplyTransformsAt(hitObject.StateUpdateTime, true);
-                        mainPieceContainer.CirclePiece.ClearTransformsAfter(hitObject.StateUpdateTime, true);
-                    });
-                }
-
-                if (hitObject is DrawableSliderRepeat repeat)
-                {
-                    repeat.Arrow.ApplyTransformsAt(hitObject.StateUpdateTime, true);
-                    repeat.Arrow.ClearTransformsAfter(hitObject.StateUpdateTime, true);
-                }
-
-                // adjust the visuals of top-level object types to make them stay on screen for longer than usual.
-                switch (hitObject)
-                {
-                    case DrawableSlider _:
-                    case DrawableHitCircle _:
-                        // Get the existing fade out transform
-                        var existing = hitObject.Transforms.LastOrDefault(t => t.TargetMember == nameof(Alpha));
-
-                        if (existing == null)
-                            return;
-
-                        hitObject.RemoveTransform(existing);
-
-                        using (hitObject.BeginAbsoluteSequence(hitObject.HitStateUpdateTime))
-                            hitObject.FadeOut(EDITOR_HIT_OBJECT_FADE_OUT_EXTENSION).Expire();
-                        break;
-                }
-            }
        }
    }
 }
@@ -11,7 +11,7 @@ namespace osu.Game.Rulesets.Osu.Edit
    public class OsuDistanceSnapGrid : CircularDistanceSnapGrid
    {
        public OsuDistanceSnapGrid(OsuHitObject hitObject, [CanBeNull] OsuHitObject nextHitObject = null)
-            : base(hitObject, hitObject.StackedEndPosition, hitObject.GetEndTime(), nextHitObject?.StartTime)
+            : base(hitObject, hitObject.StackedEndPosition, hitObject.GetEndTime(), nextHitObject?.StartTime - 1)
        {
            Masking = true;
        }
@@ -24,7 +24,7 @@ using osuTK;

 namespace osu.Game.Rulesets.Osu.Edit
 {
-    public class OsuHitObjectComposer : HitObjectComposer<OsuHitObject>
+    public class OsuHitObjectComposer : DistancedHitObjectComposer<OsuHitObject>
    {
        public OsuHitObjectComposer(Ruleset ruleset)
            : base(ruleset)
@@ -59,11 +59,6 @@ namespace osu.Game.Rulesets.Osu.Edit
        {
            LayerBelowRuleset.AddRange(new Drawable[]
            {
-                new PlayfieldBorder
-                {
-                    RelativeSizeAxes = Axes.Both,
-                    PlayfieldBorderStyle = { Value = PlayfieldBorderStyle.Corners }
-                },
                distanceSnapGridContainer = new Container
                {
                    RelativeSizeAxes = Axes.Both
@@ -128,7 +123,7 @@ namespace osu.Game.Rulesets.Osu.Edit
            }
        }

-        public override SnapResult SnapScreenSpacePositionToValidPosition(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPosition(Vector2 screenSpacePosition)
        {
            if (snapToVisibleBlueprints(screenSpacePosition, out var snapResult))
                return snapResult;
@@ -136,9 +131,9 @@ namespace osu.Game.Rulesets.Osu.Edit
            return new SnapResult(screenSpacePosition, null);
        }

-        public override SnapResult SnapScreenSpacePositionToValidTime(Vector2 screenSpacePosition)
+        public override SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePosition)
        {
-            var positionSnap = SnapScreenSpacePositionToValidPosition(screenSpacePosition);
+            var positionSnap = FindSnappedPosition(screenSpacePosition);
            if (positionSnap.ScreenSpacePosition != screenSpacePosition)
                return positionSnap;

@@ -154,7 +149,7 @@ namespace osu.Game.Rulesets.Osu.Edit
                return new SnapResult(rectangularPositionSnapGrid.ToScreenSpace(pos), null, PlayfieldAtScreenSpacePosition(screenSpacePosition));
            }

-            return base.SnapScreenSpacePositionToValidTime(screenSpacePosition);
+            return base.FindSnappedPositionAndTime(screenSpacePosition);
        }

        private bool snapToVisibleBlueprints(Vector2 screenSpacePosition, out SnapResult snapResult)
@@ -23,7 +23,7 @@ namespace osu.Game.Rulesets.Osu.Edit
    public class OsuSelectionHandler : EditorSelectionHandler
    {
        [Resolved(CanBeNull = true)]
-        private IPositionSnapProvider? positionSnapProvider { get; set; }
+        private IDistanceSnapProvider? snapProvider { get; set; }

        /// <summary>
        /// During a transform, the initial origin is stored so it can be used throughout the operation.
@@ -206,7 +206,7 @@ namespace osu.Game.Rulesets.Osu.Edit

            // Snap the slider's length to the current beat divisor
            // to calculate the final resulting duration / bounding box before the final checks.
-            slider.SnapTo(positionSnapProvider);
+            slider.SnapTo(snapProvider);

            //if sliderhead or sliderend end up outside playfield, revert scaling.
            Quad scaledQuad = getSurroundingQuad(new OsuHitObject[] { slider });
@@ -219,7 +219,7 @@ namespace osu.Game.Rulesets.Osu.Edit
                point.Position = oldControlPoints.Dequeue();

            // Snap the slider's length again to undo the potentially-invalid length applied by the previous snap.
-            slider.SnapTo(positionSnapProvider);
+            slider.SnapTo(snapProvider);
        }

        private void scaleHitObjects(OsuHitObject[] hitObjects, Anchor reference, Vector2 scale)
@@ -2,33 +2,43 @@
 // See the LICENCE file in the repository root for full licence text.

 using System;
+using System.Collections.Generic;
 using System.Linq;
-using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Sprites;
 using osu.Framework.Input.Bindings;
 using osu.Framework.Input.Events;
+using osu.Game.Beatmaps.Timing;
 using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Rulesets.Scoring;
 using osu.Game.Rulesets.UI;
 using osu.Game.Screens.Play;
+using osu.Game.Utils;

 namespace osu.Game.Rulesets.Osu.Mods
 {
-    public class OsuModAlternate : Mod, IApplicableToDrawableRuleset<OsuHitObject>, IApplicableToPlayer
+    public class OsuModAlternate : Mod, IApplicableToDrawableRuleset<OsuHitObject>
    {
        public override string Name => @"Alternate";
        public override string Acronym => @"AL";
        public override string Description => @"Don't use the same key twice in a row!";
        public override double ScoreMultiplier => 1.0;
-        public override Type[] IncompatibleMods => new[] { typeof(ModAutoplay) };
+        public override Type[] IncompatibleMods => new[] { typeof(ModAutoplay), typeof(ModRelax) };
        public override ModType Type => ModType.Conversion;
        public override IconUsage? Icon => FontAwesome.Solid.Keyboard;

-        private double firstObjectValidJudgementTime;
-        private IBindable<bool> isBreakTime;
        private const double flash_duration = 1000;
+
+        /// <summary>
+        /// A tracker for periods where alternate should not be forced (i.e. non-gameplay periods).
+        /// </summary>
+        /// <remarks>
+        /// This is different from <see cref="Player.IsBreakTime"/> in that the periods here end strictly at the first object after the break, rather than the break's end time.
+        /// </remarks>
+        private PeriodTracker nonGameplayPeriods;
+
        private OsuAction? lastActionPressed;
        private DrawableRuleset<OsuHitObject> ruleset;

@@ -39,29 +49,30 @@ namespace osu.Game.Rulesets.Osu.Mods
            ruleset = drawableRuleset;
            drawableRuleset.KeyBindingInputManager.Add(new InputInterceptor(this));

-            var firstHitObject = ruleset.Objects.FirstOrDefault();
-            firstObjectValidJudgementTime = (firstHitObject?.StartTime ?? 0) - (firstHitObject?.HitWindows.WindowFor(HitResult.Meh) ?? 0);
+            var periods = new List<Period>();
+
+            if (drawableRuleset.Objects.Any())
+            {
+                periods.Add(new Period(int.MinValue, getValidJudgementTime(ruleset.Objects.First()) - 1));
+
+                foreach (BreakPeriod b in drawableRuleset.Beatmap.Breaks)
+                    periods.Add(new Period(b.StartTime, getValidJudgementTime(ruleset.Objects.First(h => h.StartTime >= b.EndTime)) - 1));
+
+                static double getValidJudgementTime(HitObject hitObject) => hitObject.StartTime - hitObject.HitWindows.WindowFor(HitResult.Meh);
+            }
+
+            nonGameplayPeriods = new PeriodTracker(periods);

            gameplayClock = drawableRuleset.FrameStableClock;
        }

-        public void ApplyToPlayer(Player player)
-        {
-            isBreakTime = player.IsBreakTime.GetBoundCopy();
-            isBreakTime.ValueChanged += e =>
-            {
-                if (e.NewValue)
-                    lastActionPressed = null;
-            };
-        }
-
        private bool checkCorrectAction(OsuAction action)
        {
-            if (isBreakTime.Value)
-                return true;
-
-            if (gameplayClock.CurrentTime < firstObjectValidJudgementTime)
+            if (nonGameplayPeriods.IsInAny(gameplayClock.CurrentTime))
+            {
+                lastActionPressed = null;
                return true;
+            }

            switch (action)
            {
@@ -12,7 +12,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 {
    public class OsuModAutoplay : ModAutoplay
    {
-        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModMagnetised), typeof(OsuModAutopilot), typeof(OsuModSpunOut) }).ToArray();
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModMagnetised), typeof(OsuModAutopilot), typeof(OsuModSpunOut), typeof(OsuModAlternate) }).ToArray();

        public override ModReplayData CreateReplayData(IBeatmap beatmap, IReadOnlyList<Mod> mods)
            => new ModReplayData(new OsuAutoGenerator(beatmap, mods).Generate(), new ModCreatedUser { Username = "Autoplay" });
@@ -29,6 +29,8 @@ namespace osu.Game.Rulesets.Osu.Mods
        public override ModType Type => ModType.DifficultyIncrease;

        public override double ScoreMultiplier => 1.12;
+        public override Type[] IncompatibleMods => new[] { typeof(OsuModFlashlight) };
+
        private DrawableOsuBlinds blinds;

        public void ApplyToDrawableRuleset(DrawableRuleset<OsuHitObject> drawableRuleset)
@@ -13,7 +13,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 {
    public class OsuModCinema : ModCinema<OsuHitObject>
    {
-        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModMagnetised), typeof(OsuModAutopilot), typeof(OsuModSpunOut) }).ToArray();
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModMagnetised), typeof(OsuModAutopilot), typeof(OsuModSpunOut), typeof(OsuModAlternate) }).ToArray();

        public override ModReplayData CreateReplayData(IBeatmap beatmap, IReadOnlyList<Mod> mods)
            => new ModReplayData(new OsuAutoGenerator(beatmap, mods).Generate(), new ModCreatedUser { Username = "Autoplay" });
@@ -17,7 +17,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 {
    public class OsuModClassic : ModClassic, IApplicableToHitObject, IApplicableToDrawableHitObject, IApplicableToDrawableRuleset<OsuHitObject>
    {
-        public override Type[] IncompatibleMods => new[] { typeof(OsuModStrictTracking) };
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Append(typeof(OsuModStrictTracking)).ToArray();

        [SettingSource("No slider head accuracy requirement", "Scores sliders proportionally to the number of ticks hit.")]
        public Bindable<bool> NoSliderHeadAccuracy { get; } = new BindableBool(true);
@@ -2,6 +2,7 @@
 // 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;
 using osu.Framework.Input;
@@ -19,6 +20,7 @@ namespace osu.Game.Rulesets.Osu.Mods
    public class OsuModFlashlight : ModFlashlight<OsuHitObject>, IApplicableToDrawableHitObject
    {
        public override double ScoreMultiplier => 1.12;
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Append(typeof(OsuModBlinds)).ToArray();

        private const double default_follow_delay = 120;

@@ -27,8 +27,8 @@ namespace osu.Game.Rulesets.Osu.Mods

        public override Type[] IncompatibleMods => new[] { typeof(IRequiresApproachCircles), typeof(OsuModSpinIn) };

-        private const double fade_in_duration_multiplier = 0.4;
-        private const double fade_out_duration_multiplier = 0.3;
+        public const double FADE_IN_DURATION_MULTIPLIER = 0.4;
+        public const double FADE_OUT_DURATION_MULTIPLIER = 0.3;

        protected override bool IsFirstAdjustableObject(HitObject hitObject) => !(hitObject is Spinner || hitObject is SpinnerTick);

@@ -41,7 +41,7 @@ namespace osu.Game.Rulesets.Osu.Mods

            static void applyFadeInAdjustment(OsuHitObject osuObject)
            {
-                osuObject.TimeFadeIn = osuObject.TimePreempt * fade_in_duration_multiplier;
+                osuObject.TimeFadeIn = osuObject.TimePreempt * FADE_IN_DURATION_MULTIPLIER;
                foreach (var nested in osuObject.NestedHitObjects.OfType<OsuHitObject>())
                    applyFadeInAdjustment(nested);
            }
@@ -156,7 +156,7 @@ namespace osu.Game.Rulesets.Osu.Mods
            static (double fadeStartTime, double fadeDuration) getParameters(OsuHitObject hitObject)
            {
                double fadeOutStartTime = hitObject.StartTime - hitObject.TimePreempt + hitObject.TimeFadeIn;
-                double fadeOutDuration = hitObject.TimePreempt * fade_out_duration_multiplier;
+                double fadeOutDuration = hitObject.TimePreempt * FADE_OUT_DURATION_MULTIPLIER;

                // new duration from completed fade in to end (before fading out)
                double longFadeDuration = hitObject.GetEndTime() - fadeOutStartTime;
@@ -24,7 +24,7 @@ namespace osu.Game.Rulesets.Osu.Mods

        protected virtual float EndScale => 1;

-        public override Type[] IncompatibleMods => new[] { typeof(IRequiresApproachCircles), typeof(OsuModSpinIn) };
+        public override Type[] IncompatibleMods => new[] { typeof(IRequiresApproachCircles), typeof(OsuModSpinIn), typeof(OsuModObjectScaleTween) };

        protected override void ApplyIncreasedVisibilityState(DrawableHitObject hitObject, ArmedState state)
        {
@@ -22,6 +22,8 @@ namespace osu.Game.Rulesets.Osu.Mods
    {
        public override string Description => "It never gets boring!";

+        public override Type[] IncompatibleMods => base.IncompatibleMods.Append(typeof(OsuModTarget)).ToArray();
+
        private static readonly float playfield_diagonal = OsuPlayfield.BASE_SIZE.LengthFast;

        private Random? rng;
@@ -19,7 +19,7 @@ namespace osu.Game.Rulesets.Osu.Mods
    public class OsuModRelax : ModRelax, IUpdatableByPlayfield, IApplicableToDrawableRuleset<OsuHitObject>, IApplicableToPlayer
    {
        public override string Description => @"You don't need to click. Give your clicking/tapping fingers a break from the heat of things.";
-        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModAutopilot), typeof(OsuModMagnetised) }).ToArray();
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(OsuModAutopilot), typeof(OsuModMagnetised), typeof(OsuModAlternate) }).ToArray();

        /// <summary>
        /// How early before a hitobject's start time to trigger a hit.
@@ -20,7 +20,7 @@ namespace osu.Game.Rulesets.Osu.Mods
        public override ModType Type => ModType.Automation;
        public override string Description => @"Spinners will be automatically completed.";
        public override double ScoreMultiplier => 0.9;
-        public override Type[] IncompatibleMods => new[] { typeof(ModAutoplay), typeof(OsuModAutopilot) };
+        public override Type[] IncompatibleMods => new[] { typeof(ModAutoplay), typeof(OsuModAutopilot), typeof(OsuModTarget) };

        public void ApplyToDrawableHitObject(DrawableHitObject hitObject)
        {
@@ -4,7 +4,6 @@
 using System;
 using System.Linq;
 using System.Threading;
-using osu.Framework.Graphics.Sprites;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Mods;
@@ -23,11 +22,10 @@ namespace osu.Game.Rulesets.Osu.Mods
    {
        public override string Name => @"Strict Tracking";
        public override string Acronym => @"ST";
-        public override IconUsage? Icon => FontAwesome.Solid.PenFancy;
        public override ModType Type => ModType.DifficultyIncrease;
-        public override string Description => @"Follow circles just got serious...";
+        public override string Description => @"Once you start a slider, follow precisely or get a miss.";
        public override double ScoreMultiplier => 1.0;
-        public override Type[] IncompatibleMods => new[] { typeof(ModClassic) };
+        public override Type[] IncompatibleMods => new[] { typeof(ModClassic), typeof(OsuModTarget) };

        public void ApplyToDrawableHitObject(DrawableHitObject drawable)
        {
@@ -109,6 +107,18 @@ namespace osu.Game.Rulesets.Osu.Mods
                {
                    switch (e.Type)
                    {
+                        case SliderEventType.Tick:
+                            AddNested(new SliderTick
+                            {
+                                SpanIndex = e.SpanIndex,
+                                SpanStartTime = e.SpanStartTime,
+                                StartTime = e.Time,
+                                Position = Position + Path.PositionAt(e.PathProgress),
+                                StackHeight = StackHeight,
+                                Scale = Scale,
+                            });
+                            break;
+
                        case SliderEventType.Head:
                            AddNested(HeadCircle = new SliderHeadCircle
                            {
@@ -9,6 +9,10 @@ namespace osu.Game.Rulesets.Osu.Mods
 {
    public class OsuModSuddenDeath : ModSuddenDeath
    {
-        public override Type[] IncompatibleMods => base.IncompatibleMods.Append(typeof(OsuModAutopilot)).ToArray();
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[]
+        {
+            typeof(OsuModAutopilot),
+            typeof(OsuModTarget),
+        }).ToArray();
    }
 }
@@ -42,7 +42,14 @@ namespace osu.Game.Rulesets.Osu.Mods
        public override string Description => @"Practice keeping up with the beat of the song.";
        public override double ScoreMultiplier => 1;

-        public override Type[] IncompatibleMods => new[] { typeof(IRequiresApproachCircles) };
+        public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[]
+        {
+            typeof(IRequiresApproachCircles),
+            typeof(OsuModRandom),
+            typeof(OsuModSpunOut),
+            typeof(OsuModStrictTracking),
+            typeof(OsuModSuddenDeath)
+        }).ToArray();

        [SettingSource("Seed", "Use a custom seed instead of a random one", SettingControlType = typeof(SettingsNumberBox))]
        public Bindable<int?> Seed { get; } = new Bindable<int?>
@@ -6,10 +6,10 @@ using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Game.Rulesets.Objects.Drawables;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Primitives;
 using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Osu.Judgements;
 using osu.Game.Graphics.Containers;
-using osu.Game.Rulesets.Osu.UI;
 using osuTK;

 namespace osu.Game.Rulesets.Osu.Objects.Drawables
@@ -21,10 +21,10 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables
        public readonly IBindable<float> ScaleBindable = new BindableFloat();
        public readonly IBindable<int> IndexInCurrentComboBindable = new Bindable<int>();

-        // Must be set to update IsHovered as it's used in relax mdo to detect osu hit objects.
+        // Must be set to update IsHovered as it's used in relax mod to detect osu hit objects.
        public override bool HandlePositionalInput => true;

-        protected override float SamplePlaybackPosition => HitObject.X / OsuPlayfield.BASE_SIZE.X;
+        protected override float SamplePlaybackPosition => CalculateDrawableRelativePosition(this);

        /// <summary>
        /// Whether this <see cref="DrawableOsuHitObject"/> can be hit, given a time value.
@@ -89,6 +89,14 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables
        /// </summary>
        public void MissForcefully() => ApplyResult(r => r.Type = r.Judgement.MinResult);

+        private RectangleF parentScreenSpaceRectangle => ((DrawableOsuHitObject)ParentHitObject)?.parentScreenSpaceRectangle ?? Parent.ScreenSpaceDrawQuad.AABBFloat;
+
+        /// <summary>
+        /// Calculates the position of the given <paramref name="drawable"/> relative to the playfield area.
+        /// </summary>
+        /// <param name="drawable">The drawable to calculate its relative position.</param>
+        protected float CalculateDrawableRelativePosition(Drawable drawable) => (drawable.ScreenSpaceDrawQuad.Centre.X - parentScreenSpaceRectangle.X) / parentScreenSpaceRectangle.Width;
+
        protected override JudgementResult CreateResult(Judgement judgement) => new OsuJudgementResult(HitObject, judgement);
    }
 }
@@ -13,7 +13,6 @@ using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Osu.Skinning;
 using osu.Game.Rulesets.Osu.Skinning.Default;
-using osu.Game.Rulesets.Osu.UI;
 using osu.Game.Rulesets.Scoring;
 using osu.Game.Skinning;
 using osuTK;
@@ -208,7 +207,7 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables

            if (Tracking.Value && slidingSample != null)
                // keep the sliding sample playing at the current tracking position
-                slidingSample.Balance.Value = CalculateSamplePlaybackBalance(Ball.X / OsuPlayfield.BASE_SIZE.X);
+                slidingSample.Balance.Value = CalculateSamplePlaybackBalance(CalculateDrawableRelativePosition(Ball));

            double completionProgress = Math.Clamp((Time.Current - HitObject.StartTime) / HitObject.Duration, 0, 1);

@@ -195,16 +195,16 @@ namespace osu.Game.Rulesets.Osu.Skinning.Default

        public void UpdateProgress(double completionProgress)
        {
-            var newPos = drawableSlider.HitObject.CurvePositionAt(completionProgress);
+            Position = drawableSlider.HitObject.CurvePositionAt(completionProgress);

-            var diff = lastPosition.HasValue ? lastPosition.Value - newPos : newPos - drawableSlider.HitObject.CurvePositionAt(completionProgress + 0.01f);
-            if (diff == Vector2.Zero)
+            var diff = lastPosition.HasValue ? lastPosition.Value - Position : Position - drawableSlider.HitObject.CurvePositionAt(completionProgress + 0.01f);
+
+            // Ensure the value is substantially high enough to allow for Atan2 to get a valid angle.
+            if (diff.LengthFast < 0.01f)
                return;

-            Position = newPos;
            ball.Rotation = -90 + (float)(-Math.Atan2(diff.X, diff.Y) * 180 / Math.PI);
-
-            lastPosition = newPos;
+            lastPosition = Position;
        }

        private class FollowCircleContainer : CircularContainer
@@ -3,10 +3,10 @@

 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
+using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Sprites;
-using osu.Framework.Graphics.Textures;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Sprites;
 using osu.Game.Rulesets.Objects.Drawables;
@@ -16,63 +16,61 @@ using osu.Game.Skinning;
 using osuTK;
 using osuTK.Graphics;

+#nullable enable
+
 namespace osu.Game.Rulesets.Osu.Skinning.Legacy
 {
    public class LegacyMainCirclePiece : CompositeDrawable
    {
        public override bool RemoveCompletedTransforms => false;

-        private readonly string priorityLookup;
+        /// <summary>
+        /// A prioritised prefix to perform texture lookups with.
+        /// </summary>
+        private readonly string? priorityLookupPrefix;
+
        private readonly bool hasNumber;

-        public LegacyMainCirclePiece(string priorityLookup = null, bool hasNumber = true)
+        protected Drawable CircleSprite = null!;
+        protected Drawable OverlaySprite = null!;
+
+        protected Container OverlayLayer { get; private set; } = null!;
+
+        private SkinnableSpriteText hitCircleText = null!;
+
+        private readonly Bindable<Color4> accentColour = new Bindable<Color4>();
+        private readonly IBindable<int> indexInCurrentCombo = new Bindable<int>();
+
+        [Resolved(canBeNull: true)]
+        private DrawableHitObject? drawableObject { get; set; }
+
+        [Resolved]
+        private ISkinSource skin { get; set; } = null!;
+
+        public LegacyMainCirclePiece(string? priorityLookupPrefix = null, bool hasNumber = true)
        {
-            this.priorityLookup = priorityLookup;
+            this.priorityLookupPrefix = priorityLookupPrefix;
            this.hasNumber = hasNumber;

            Size = new Vector2(OsuHitObject.OBJECT_RADIUS * 2);
        }

-        private Drawable hitCircleSprite;
-
-        protected Container OverlayLayer { get; private set; }
-
-        private Drawable hitCircleOverlay;
-        private SkinnableSpriteText hitCircleText;
-
-        private readonly Bindable<Color4> accentColour = new Bindable<Color4>();
-        private readonly IBindable<int> indexInCurrentCombo = new Bindable<int>();
-
-        [Resolved]
-        private DrawableHitObject drawableObject { get; set; }
-
-        [Resolved]
-        private ISkinSource skin { get; set; }
-
        [BackgroundDependencyLoader]
        private void load()
        {
-            var drawableOsuObject = (DrawableOsuHitObject)drawableObject;
+            var drawableOsuObject = (DrawableOsuHitObject?)drawableObject;

-            bool allowFallback = false;
-
-            // attempt lookup using priority specification
-            Texture baseTexture = getTextureWithFallback(string.Empty);
-
-            // if the base texture was not found without a fallback, switch on fallback mode and re-perform the lookup.
-            if (baseTexture == null)
-            {
-                allowFallback = true;
-                baseTexture = getTextureWithFallback(string.Empty);
-            }
+            // if a base texture for the specified prefix exists, continue using it for subsequent lookups.
+            // otherwise fall back to the default prefix "hitcircle".
+            string circleName = (priorityLookupPrefix != null && skin.GetTexture(priorityLookupPrefix) != null) ? priorityLookupPrefix : @"hitcircle";

            // at this point, any further texture fetches should be correctly using the priority source if the base texture was retrieved using it.
-            // the flow above handles the case where a sliderendcircle.png is retrieved from the skin, but sliderendcircleoverlay.png doesn't exist.
-            // expected behaviour in this scenario is not showing the overlay, rather than using hitcircleoverlay.png (potentially from the default/fall-through skin).
+            // the conditional above handles the case where a sliderendcircle.png is retrieved from the skin, but sliderendcircleoverlay.png doesn't exist.
+            // expected behaviour in this scenario is not showing the overlay, rather than using hitcircleoverlay.png.

            InternalChildren = new[]
            {
-                hitCircleSprite = new KiaiFlashingDrawable(() => new Sprite { Texture = baseTexture })
+                CircleSprite = new KiaiFlashingDrawable(() => new Sprite { Texture = skin.GetTexture(circleName) })
                {
                    Anchor = Anchor.Centre,
                    Origin = Anchor.Centre,
@@ -81,7 +79,7 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
                {
                    Anchor = Anchor.Centre,
                    Origin = Anchor.Centre,
-                    Child = hitCircleOverlay = new KiaiFlashingDrawable(() => getAnimationWithFallback(@"overlay", 1000 / 2d))
+                    Child = OverlaySprite = new KiaiFlashingDrawable(() => skin.GetAnimation(@$"{circleName}overlay", true, true, frameLength: 1000 / 2d))
                    {
                        Anchor = Anchor.Centre,
                        Origin = Anchor.Centre,
@@ -105,39 +103,12 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
            bool overlayAboveNumber = skin.GetConfig<OsuSkinConfiguration, bool>(OsuSkinConfiguration.HitCircleOverlayAboveNumber)?.Value ?? true;

            if (overlayAboveNumber)
-                OverlayLayer.ChangeChildDepth(hitCircleOverlay, float.MinValue);
+                OverlayLayer.ChangeChildDepth(OverlaySprite, float.MinValue);

-            accentColour.BindTo(drawableObject.AccentColour);
-            indexInCurrentCombo.BindTo(drawableOsuObject.IndexInCurrentComboBindable);
-
-            Texture getTextureWithFallback(string name)
+            if (drawableOsuObject != null)
            {
-                Texture tex = null;
-
-                if (!string.IsNullOrEmpty(priorityLookup))
-                {
-                    tex = skin.GetTexture($"{priorityLookup}{name}");
-
-                    if (!allowFallback)
-                        return tex;
-                }
-
-                return tex ?? skin.GetTexture($"hitcircle{name}");
-            }
-
-            Drawable getAnimationWithFallback(string name, double frameLength)
-            {
-                Drawable animation = null;
-
-                if (!string.IsNullOrEmpty(priorityLookup))
-                {
-                    animation = skin.GetAnimation($"{priorityLookup}{name}", true, true, frameLength: frameLength);
-
-                    if (!allowFallback)
-                        return animation;
-                }
-
-                return animation ?? skin.GetAnimation($"hitcircle{name}", true, true, frameLength: frameLength);
+                accentColour.BindTo(drawableOsuObject.AccentColour);
+                indexInCurrentCombo.BindTo(drawableOsuObject.IndexInCurrentComboBindable);
            }
        }

@@ -145,28 +116,31 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
        {
            base.LoadComplete();

-            accentColour.BindValueChanged(colour => hitCircleSprite.Colour = LegacyColourCompatibility.DisallowZeroAlpha(colour.NewValue), true);
+            accentColour.BindValueChanged(colour => CircleSprite.Colour = LegacyColourCompatibility.DisallowZeroAlpha(colour.NewValue), true);
            if (hasNumber)
                indexInCurrentCombo.BindValueChanged(index => hitCircleText.Text = (index.NewValue + 1).ToString(), true);

-            drawableObject.ApplyCustomUpdateState += updateStateTransforms;
-            updateStateTransforms(drawableObject, drawableObject.State.Value);
+            if (drawableObject != null)
+            {
+                drawableObject.ApplyCustomUpdateState += updateStateTransforms;
+                updateStateTransforms(drawableObject, drawableObject.State.Value);
+            }
        }

        private void updateStateTransforms(DrawableHitObject drawableHitObject, ArmedState state)
        {
            const double legacy_fade_duration = 240;

-            using (BeginAbsoluteSequence(drawableObject.HitStateUpdateTime))
+            using (BeginAbsoluteSequence(drawableObject.AsNonNull().HitStateUpdateTime))
            {
                switch (state)
                {
                    case ArmedState.Hit:
-                        hitCircleSprite.FadeOut(legacy_fade_duration, Easing.Out);
-                        hitCircleSprite.ScaleTo(1.4f, legacy_fade_duration, Easing.Out);
+                        CircleSprite.FadeOut(legacy_fade_duration, Easing.Out);
+                        CircleSprite.ScaleTo(1.4f, legacy_fade_duration, Easing.Out);

-                        hitCircleOverlay.FadeOut(legacy_fade_duration, Easing.Out);
-                        hitCircleOverlay.ScaleTo(1.4f, legacy_fade_duration, Easing.Out);
+                        OverlaySprite.FadeOut(legacy_fade_duration, Easing.Out);
+                        OverlaySprite.ScaleTo(1.4f, legacy_fade_duration, Easing.Out);

                        if (hasNumber)
                        {
@@ -35,6 +35,9 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
                    case OsuSkinComponents.FollowPoint:
                        return this.GetAnimation(component.LookupName, true, true, true, startAtCurrentTime: false);

+                    case OsuSkinComponents.SliderScorePoint:
+                        return this.GetAnimation(component.LookupName, false, false);
+
                    case OsuSkinComponents.SliderFollowCircle:
                        var followCircle = this.GetAnimation("sliderfollowcircle", true, true, true);
                        if (followCircle != null)
@@ -123,6 +126,9 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy

                    case OsuSkinComponents.ApproachCircle:
                        return new LegacyApproachCircle();
+
+                    default:
+                        throw new UnsupportedSkinComponentException(component);
                }
            }

@@ -33,6 +33,7 @@ namespace osu.Game.Rulesets.Osu.UI
                },
                new SettingsCheckbox
                {
+                    ClassicDefault = false,
                    LabelText = "Snaking out sliders",
                    Current = config.GetBindable<bool>(OsuRulesetSetting.SnakingOutSliders)
                },
@@ -28,9 +28,7 @@ namespace osu.Game.Rulesets.Taiko.Tests

                // flying hits all land in one common scrolling container (and stay there for rewind purposes),
                // so we need to manually get the latest one.
-                flyingHit = this.ChildrenOfType<DrawableFlyingHit>()
-                                .OrderByDescending(h => h.HitObject.StartTime)
-                                .FirstOrDefault();
+                flyingHit = this.ChildrenOfType<DrawableFlyingHit>().MaxBy(h => h.HitObject.StartTime);
            });

            AddAssert("hit type is correct", () => flyingHit.HitObject.Type == hitType);
@@ -3,7 +3,7 @@
  <ItemGroup Label="Package References">
    <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
-    <PackageReference Include="NUnit" Version="3.13.2" />
+    <PackageReference Include="NUnit" Version="3.13.3" />
    <PackageReference Include="NUnit3TestAdapter" Version="4.1.0" />
    <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
  </ItemGroup>
@@ -141,7 +141,13 @@ namespace osu.Game.Rulesets.Taiko.Difficulty
                double colourPeak = colourPeaks[i] * colour_skill_multiplier;
                double rhythmPeak = rhythmPeaks[i] * rhythm_skill_multiplier;
                double staminaPeak = (staminaRightPeaks[i] + staminaLeftPeaks[i]) * stamina_skill_multiplier * staminaPenalty;
-                peaks.Add(norm(2, colourPeak, rhythmPeak, staminaPeak));
+
+                double peak = norm(2, colourPeak, rhythmPeak, staminaPeak);
+
+                // Sections with 0 strain are excluded to avoid worst-case time complexity of the following sort (e.g. /b/2351871).
+                // These sections will not contribute to the difficulty.
+                if (peak > 0)
+                    peaks.Add(peak);
            }

            double difficulty = 0;
@@ -57,6 +57,10 @@ namespace osu.Game.Rulesets.Taiko.Skinning.Legacy
                    case TaikoSkinComponents.DrumRollTick:
                        return this.GetAnimation("sliderscorepoint", false, false);

+                    case TaikoSkinComponents.Swell:
+                        // todo: support taiko legacy swell (https://github.com/ppy/osu/issues/13601).
+                        return null;
+
                    case TaikoSkinComponents.HitTarget:
                        if (GetTexture("taikobigcircle") != null)
                            return new TaikoLegacyHitTarget();
@@ -119,6 +123,9 @@ namespace osu.Game.Rulesets.Taiko.Skinning.Legacy

                    case TaikoSkinComponents.Mascot:
                        return new DrawableTaikoMascot();
+
+                    default:
+                        throw new UnsupportedSkinComponentException(component);
                }
            }

@@ -136,6 +136,37 @@ namespace osu.Game.Tests.Database
            });
        }

+        [Test]
+        public void TestAddFileToAsyncImportedBeatmap()
+        {
+            RunTestWithRealm((realm, storage) =>
+            {
+                BeatmapSetInfo? detachedSet = null;
+
+                using (var importer = new BeatmapModelManager(realm, storage))
+                using (new RealmRulesetStore(realm, storage))
+                {
+                    Task.Run(async () =>
+                    {
+                        Live<BeatmapSetInfo>? beatmapSet;
+
+                        using (var reader = new ZipArchiveReader(TestResources.GetTestBeatmapStream()))
+                            // ReSharper disable once AccessToDisposedClosure
+                            beatmapSet = await importer.Import(reader);
+
+                        Assert.NotNull(beatmapSet);
+                        Debug.Assert(beatmapSet != null);
+
+                        // Intentionally detach on async thread as to not trigger a refresh on the main thread.
+                        beatmapSet.PerformRead(s => detachedSet = s.Detach());
+                    }).WaitSafely();
+
+                    Debug.Assert(detachedSet != null);
+                    importer.AddFile(detachedSet, new MemoryStream(), "test");
+                }
+            });
+        }
+
        [Test]
        public void TestImportBeatmapThenCleanup()
        {
@@ -3,6 +3,7 @@

 using NUnit.Framework;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Testing;
@@ -69,7 +70,7 @@ namespace osu.Game.Tests.Editing
        [TestCase(2)]
        public void TestSliderMultiplier(float multiplier)
        {
-            AddStep($"set multiplier = {multiplier}", () => composer.EditorBeatmap.Difficulty.SliderMultiplier = multiplier);
+            AddStep($"set slider multiplier = {multiplier}", () => composer.EditorBeatmap.Difficulty.SliderMultiplier = multiplier);

            assertSnapDistance(100 * multiplier);
        }
@@ -212,15 +213,17 @@ namespace osu.Game.Tests.Editing
            => AddAssert($"distance = {distance} -> duration = {expectedDuration}", () => composer.DistanceToDuration(new HitObject(), distance) == expectedDuration);

        private void assertSnappedDuration(float distance, double expectedDuration)
-            => AddAssert($"distance = {distance} -> duration = {expectedDuration} (snapped)", () => composer.GetSnappedDurationFromDistance(new HitObject(), distance) == expectedDuration);
+            => AddAssert($"distance = {distance} -> duration = {expectedDuration} (snapped)", () => composer.FindSnappedDuration(new HitObject(), distance) == expectedDuration);

        private void assertSnappedDistance(float distance, float expectedDistance)
-            => AddAssert($"distance = {distance} -> distance = {expectedDistance} (snapped)", () => composer.GetSnappedDistanceFromDistance(new HitObject(), distance) == expectedDistance);
+            => AddAssert($"distance = {distance} -> distance = {expectedDistance} (snapped)", () => composer.FindSnappedDistance(new HitObject(), distance) == expectedDistance);

        private class TestHitObjectComposer : OsuHitObjectComposer
        {
            public new EditorBeatmap EditorBeatmap => base.EditorBeatmap;

+            public new Bindable<double> DistanceSpacingMultiplier => base.DistanceSpacingMultiplier;
+
            public TestHitObjectComposer()
                : base(new OsuRuleset())
            {
@@ -160,6 +160,40 @@ namespace osu.Game.Tests.Gameplay
            assertHealthNotEqualTo(1);
        }

+        [Test]
+        public void TestFailConditions()
+        {
+            var beatmap = createBeatmap(0, 1000);
+            createProcessor(beatmap);
+
+            AddStep("setup fail conditions", () => processor.FailConditions += ((_, result) => result.Type == HitResult.Miss));
+
+            AddStep("apply perfect hit result", () => processor.ApplyResult(new JudgementResult(beatmap.HitObjects[0], new Judgement()) { Type = HitResult.Perfect }));
+            AddAssert("not failed", () => !processor.HasFailed);
+            AddStep("apply miss hit result", () => processor.ApplyResult(new JudgementResult(beatmap.HitObjects[0], new Judgement()) { Type = HitResult.Miss }));
+            AddAssert("failed", () => processor.HasFailed);
+        }
+
+        [TestCase(HitResult.Miss)]
+        [TestCase(HitResult.Meh)]
+        public void TestMultipleFailConditions(HitResult resultApplied)
+        {
+            var beatmap = createBeatmap(0, 1000);
+            createProcessor(beatmap);
+
+            AddStep("setup multiple fail conditions", () =>
+            {
+                processor.FailConditions += ((_, result) => result.Type == HitResult.Miss);
+                processor.FailConditions += ((_, result) => result.Type == HitResult.Meh);
+            });
+
+            AddStep("apply perfect hit result", () => processor.ApplyResult(new JudgementResult(beatmap.HitObjects[0], new Judgement()) { Type = HitResult.Perfect }));
+            AddAssert("not failed", () => !processor.HasFailed);
+
+            AddStep($"apply {resultApplied.ToString().ToLower()} hit result", () => processor.ApplyResult(new JudgementResult(beatmap.HitObjects[0], new Judgement()) { Type = resultApplied }));
+            AddAssert("failed", () => processor.HasFailed);
+        }
+
        [Test]
        public void TestBonusObjectsExcludedFromDrain()
        {
@@ -26,6 +26,12 @@ namespace osu.Game.Tests.Gameplay
            Dependencies.Cache(localConfig = new OsuConfigManager(LocalStorage));
        }

+        [SetUpSteps]
+        public void SetUpSteps()
+        {
+            AddStep("reset audio offset", () => localConfig.SetValue(OsuSetting.AudioOffset, 0.0));
+        }
+
        [Test]
        public void TestStartThenElapsedTime()
        {
@@ -36,7 +42,7 @@ namespace osu.Game.Tests.Gameplay
                var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
                working.LoadTrack();

-                Add(gameplayClockContainer = new MasterGameplayClockContainer(working, 0));
+                Child = gameplayClockContainer = new MasterGameplayClockContainer(working, 0);
            });

            AddStep("start clock", () => gameplayClockContainer.Start());
@@ -53,7 +59,7 @@ namespace osu.Game.Tests.Gameplay
                var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
                working.LoadTrack();

-                Add(gameplayClockContainer = new MasterGameplayClockContainer(working, 0));
+                Child = gameplayClockContainer = new MasterGameplayClockContainer(working, 0);
            });

            AddStep("start clock", () => gameplayClockContainer.Start());
@@ -73,26 +79,29 @@ namespace osu.Game.Tests.Gameplay
        public void TestSeekPerformsInGameplayTime(
            [Values(1.0, 0.5, 2.0)] double clockRate,
            [Values(0.0, 200.0, -200.0)] double userOffset,
-            [Values(false, true)] bool whileStopped)
+            [Values(false, true)] bool whileStopped,
+            [Values(false, true)] bool setAudioOffsetBeforeConstruction)
        {
            ClockBackedTestWorkingBeatmap working = null;
            GameplayClockContainer gameplayClockContainer = null;

+            if (setAudioOffsetBeforeConstruction)
+                AddStep($"preset audio offset to {userOffset}", () => localConfig.SetValue(OsuSetting.AudioOffset, userOffset));
+
            AddStep("create container", () =>
            {
                working = new ClockBackedTestWorkingBeatmap(new OsuRuleset().RulesetInfo, new FramedClock(new ManualClock()), Audio);
                working.LoadTrack();

-                Add(gameplayClockContainer = new MasterGameplayClockContainer(working, 0));
+                Child = gameplayClockContainer = new MasterGameplayClockContainer(working, 0);

-                if (whileStopped)
-                    gameplayClockContainer.Stop();
-
-                gameplayClockContainer.Reset();
+                gameplayClockContainer.Reset(startClock: !whileStopped);
            });

            AddStep($"set clock rate to {clockRate}", () => working.Track.AddAdjustment(AdjustableProperty.Frequency, new BindableDouble(clockRate)));
-            AddStep($"set audio offset to {userOffset}", () => localConfig.SetValue(OsuSetting.AudioOffset, userOffset));
+
+            if (!setAudioOffsetBeforeConstruction)
+                AddStep($"set audio offset to {userOffset}", () => localConfig.SetValue(OsuSetting.AudioOffset, userOffset));

            AddStep("seek to 2500", () => gameplayClockContainer.Seek(2500));
            AddAssert("gameplay clock time = 2500", () => Precision.AlmostEquals(gameplayClockContainer.CurrentTime, 2500, 10f));
@@ -88,7 +88,7 @@ namespace osu.Game.Tests.Gameplay
        [Test]
        public void TestSampleHasLifetimeEndWithInitialClockTime()
        {
-            GameplayClockContainer gameplayContainer = null;
+            MasterGameplayClockContainer gameplayContainer = null;
            DrawableStoryboardSample sample = null;

            AddStep("create container", () =>
@@ -96,8 +96,11 @@ namespace osu.Game.Tests.Gameplay
                var working = CreateWorkingBeatmap(new OsuRuleset().RulesetInfo);
                working.LoadTrack();

-                Add(gameplayContainer = new MasterGameplayClockContainer(working, 1000, true)
+                const double start_time = 1000;
+
+                Add(gameplayContainer = new MasterGameplayClockContainer(working, start_time)
                {
+                    StartTime = start_time,
                    IsPaused = { Value = true },
                    Child = new FrameStabilityContainer
                    {
@@ -0,0 +1,36 @@
+// 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 NUnit.Framework;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Osu.Mods;
+
+namespace osu.Game.Tests.Mods
+{
+    public class ModSettingsTest
+    {
+        [Test]
+        public void TestModSettingsUnboundWhenCopied()
+        {
+            var original = new OsuModDoubleTime();
+            var copy = (OsuModDoubleTime)original.DeepClone();
+
+            original.SpeedChange.Value = 2;
+
+            Assert.That(original.SpeedChange.Value, Is.EqualTo(2.0));
+            Assert.That(copy.SpeedChange.Value, Is.EqualTo(1.5));
+        }
+
+        [Test]
+        public void TestMultiModSettingsUnboundWhenCopied()
+        {
+            var original = new MultiMod(new OsuModDoubleTime());
+            var copy = (MultiMod)original.DeepClone();
+
+            ((OsuModDoubleTime)original.Mods[0]).SpeedChange.Value = 2;
+
+            Assert.That(((OsuModDoubleTime)original.Mods[0]).SpeedChange.Value, Is.EqualTo(2.0));
+            Assert.That(((OsuModDoubleTime)copy.Mods[0]).SpeedChange.Value, Is.EqualTo(1.5));
+        }
+    }
+}
@@ -137,33 +137,137 @@ namespace osu.Game.Tests.Mods
            // incompatible pair.
            new object[]
            {
-                new Mod[] { new OsuModDoubleTime(), new OsuModHalfTime() },
-                new[] { typeof(OsuModDoubleTime), typeof(OsuModHalfTime) }
+                new Mod[] { new OsuModHidden(), new OsuModApproachDifferent() },
+                new[] { typeof(OsuModHidden), typeof(OsuModApproachDifferent) }
            },
            // incompatible pair with derived class.
            new object[]
            {
-                new Mod[] { new OsuModNightcore(), new OsuModHalfTime() },
-                new[] { typeof(OsuModNightcore), typeof(OsuModHalfTime) }
+                new Mod[] { new OsuModDeflate(), new OsuModApproachDifferent() },
+                new[] { typeof(OsuModDeflate), typeof(OsuModApproachDifferent) }
            },
            // system mod.
            new object[]
            {
-                new Mod[] { new OsuModDoubleTime(), new OsuModTouchDevice() },
+                new Mod[] { new OsuModHidden(), new OsuModTouchDevice() },
                new[] { typeof(OsuModTouchDevice) }
            },
            // multi mod.
            new object[]
            {
-                new Mod[] { new MultiMod(new OsuModHalfTime()), new OsuModDaycore() },
+                new Mod[] { new MultiMod(new OsuModSuddenDeath(), new OsuModPerfect()) },
                new[] { typeof(MultiMod) }
            },
+            // invalid multiplayer mod is valid for local.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new InvalidMultiplayerMod() },
+                null
+            },
+            // invalid free mod is valid for local.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new InvalidMultiplayerFreeMod() },
+                null
+            },
            // valid pair.
            new object[]
            {
-                new Mod[] { new OsuModDoubleTime(), new OsuModHardRock() },
+                new Mod[] { new OsuModHidden(), new OsuModHardRock() },
                null
-            }
+            },
+        };
+
+        private static readonly object[] invalid_multiplayer_mod_test_scenarios =
+        {
+            // incompatible pair.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new OsuModApproachDifferent() },
+                new[] { typeof(OsuModHidden), typeof(OsuModApproachDifferent) }
+            },
+            // incompatible pair with derived class.
+            new object[]
+            {
+                new Mod[] { new OsuModDeflate(), new OsuModApproachDifferent() },
+                new[] { typeof(OsuModDeflate), typeof(OsuModApproachDifferent) }
+            },
+            // system mod.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new OsuModTouchDevice() },
+                new[] { typeof(OsuModTouchDevice) }
+            },
+            // multi mod.
+            new object[]
+            {
+                new Mod[] { new MultiMod(new OsuModSuddenDeath(), new OsuModPerfect()) },
+                new[] { typeof(MultiMod) }
+            },
+            // invalid multiplayer mod.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new InvalidMultiplayerMod() },
+                new[] { typeof(InvalidMultiplayerMod) }
+            },
+            // invalid free mod is valid for multiplayer global.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new InvalidMultiplayerFreeMod() },
+                null
+            },
+            // valid pair.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new OsuModHardRock() },
+                null
+            },
+        };
+
+        private static readonly object[] invalid_free_mod_test_scenarios =
+        {
+            // system mod.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new OsuModTouchDevice() },
+                new[] { typeof(OsuModTouchDevice) }
+            },
+            // multi mod.
+            new object[]
+            {
+                new Mod[] { new MultiMod(new OsuModSuddenDeath(), new OsuModPerfect()) },
+                new[] { typeof(MultiMod) }
+            },
+            // invalid multiplayer mod.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new InvalidMultiplayerMod() },
+                new[] { typeof(InvalidMultiplayerMod) }
+            },
+            // invalid free mod.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new InvalidMultiplayerFreeMod() },
+                new[] { typeof(InvalidMultiplayerFreeMod) }
+            },
+            // incompatible pair is valid for free mods.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new OsuModApproachDifferent() },
+                null,
+            },
+            // incompatible pair with derived class is valid for free mods.
+            new object[]
+            {
+                new Mod[] { new OsuModDeflate(), new OsuModSpinIn() },
+                null,
+            },
+            // valid pair.
+            new object[]
+            {
+                new Mod[] { new OsuModHidden(), new OsuModHardRock() },
+                null
+            },
        };

        [TestCaseSource(nameof(invalid_mod_test_scenarios))]
@@ -179,6 +283,32 @@ namespace osu.Game.Tests.Mods
                Assert.That(invalid.Select(t => t.GetType()), Is.EquivalentTo(expectedInvalid));
        }

+        [TestCaseSource(nameof(invalid_multiplayer_mod_test_scenarios))]
+        public void TestInvalidMultiplayerModScenarios(Mod[] inputMods, Type[] expectedInvalid)
+        {
+            bool isValid = ModUtils.CheckValidRequiredModsForMultiplayer(inputMods, out var invalid);
+
+            Assert.That(isValid, Is.EqualTo(expectedInvalid == null));
+
+            if (isValid)
+                Assert.IsNull(invalid);
+            else
+                Assert.That(invalid.Select(t => t.GetType()), Is.EquivalentTo(expectedInvalid));
+        }
+
+        [TestCaseSource(nameof(invalid_free_mod_test_scenarios))]
+        public void TestInvalidFreeModScenarios(Mod[] inputMods, Type[] expectedInvalid)
+        {
+            bool isValid = ModUtils.CheckValidFreeModsForMultiplayer(inputMods, out var invalid);
+
+            Assert.That(isValid, Is.EqualTo(expectedInvalid == null));
+
+            if (isValid)
+                Assert.IsNull(invalid);
+            else
+                Assert.That(invalid.Select(t => t.GetType()), Is.EquivalentTo(expectedInvalid));
+        }
+
        public abstract class CustomMod1 : Mod, IModCompatibilitySpecification
        {
        }
@@ -187,6 +317,27 @@ namespace osu.Game.Tests.Mods
        {
        }

+        public class InvalidMultiplayerMod : Mod
+        {
+            public override string Name => string.Empty;
+            public override string Description => string.Empty;
+            public override string Acronym => string.Empty;
+            public override double ScoreMultiplier => 1;
+            public override bool HasImplementation => true;
+            public override bool ValidForMultiplayer => false;
+            public override bool ValidForMultiplayerAsFreeMod => false;
+        }
+
+        private class InvalidMultiplayerFreeMod : Mod
+        {
+            public override string Name => string.Empty;
+            public override string Description => string.Empty;
+            public override string Acronym => string.Empty;
+            public override double ScoreMultiplier => 1;
+            public override bool HasImplementation => true;
+            public override bool ValidForMultiplayerAsFreeMod => false;
+        }
+
        public interface IModCompatibilitySpecification
        {
        }
@@ -0,0 +1,65 @@
+// 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 NUnit.Framework;
+using osu.Game.Rulesets;
+using osu.Game.Rulesets.Catch;
+using osu.Game.Rulesets.Mania;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Osu;
+using osu.Game.Rulesets.Taiko;
+using osu.Game.Utils;
+
+namespace osu.Game.Tests.Mods
+{
+    [TestFixture]
+    public class MultiModIncompatibilityTest
+    {
+        /// <summary>
+        /// Ensures that all mods grouped into <see cref="MultiMod"/>s, as declared by the default rulesets, are pairwise incompatible with each other.
+        /// </summary>
+        [TestCase(typeof(OsuRuleset))]
+        [TestCase(typeof(TaikoRuleset))]
+        [TestCase(typeof(CatchRuleset))]
+        [TestCase(typeof(ManiaRuleset))]
+        public void TestAllMultiModsFromRulesetAreIncompatible(Type rulesetType)
+        {
+            var ruleset = (Ruleset)Activator.CreateInstance(rulesetType);
+            Assert.That(ruleset, Is.Not.Null);
+
+            var allMultiMods = getMultiMods(ruleset);
+
+            Assert.Multiple(() =>
+            {
+                foreach (var multiMod in allMultiMods)
+                {
+                    int modCount = multiMod.Mods.Length;
+
+                    for (int i = 0; i < modCount; ++i)
+                    {
+                        // indexing from i + 1 ensures that only pairs of different mods are checked, and are checked only once
+                        // (indexing from 0 would check each pair twice, and also check each mod against itself).
+                        for (int j = i + 1; j < modCount; ++j)
+                        {
+                            var firstMod = multiMod.Mods[i];
+                            var secondMod = multiMod.Mods[j];
+
+                            Assert.That(
+                                ModUtils.CheckCompatibleSet(new[] { firstMod, secondMod }), Is.False,
+                                $"{firstMod.Name} ({firstMod.Acronym}) and {secondMod.Name} ({secondMod.Acronym}) should be incompatible.");
+                        }
+                    }
+                }
+            });
+        }
+
+        /// <remarks>
+        /// This local helper is used rather than <see cref="Ruleset.CreateAllMods"/>, because the aforementioned method flattens multi mods.
+        /// </remarks>>
+        private static IEnumerable<MultiMod> getMultiMods(Ruleset ruleset)
+            => Enum.GetValues(typeof(ModType)).Cast<ModType>().SelectMany(ruleset.GetModsFor).OfType<MultiMod>();
+    }
+}
--- a/Show More
+++ b/Show More