Merge branch 'master' into master

osu.Game.Rulesets.Osu.Tests/Mods/TestSceneOsuModDoubleTime.cs

@@ -22,7 +22,7 @@ namespace osu.Game.Rulesets.Osu.Tests.Mods
             {
                 Mod = mod,
                 PassCondition = () => Player.ScoreProcessor.JudgedHits >= 2 &&
-                                      Precision.AlmostEquals(Player.GameplayClockContainer.GameplayClock.Rate, mod.SpeedChange.Value)
+                                      Precision.AlmostEquals(Player.GameplayClockContainer.Rate, mod.SpeedChange.Value)
             });
         }
     }

osu.Game.Rulesets.Osu/Skinning/Default/SpinnerRotationTracker.cs

@@ -59,7 +59,7 @@ namespace osu.Game.Rulesets.Osu.Skinning.Default
         private bool rotationTransferred;
 
         [Resolved(canBeNull: true)]
-        private GameplayClock gameplayClock { get; set; }
+        private IGameplayClock gameplayClock { get; set; }
 
         protected override void Update()
         {

osu.Game.Tests/Gameplay/TestSceneMasterGameplayClockContainer.cs

@@ -45,7 +45,7 @@ namespace osu.Game.Tests.Gameplay
             });
 
             AddStep("start clock", () => gameplayClockContainer.Start());
-            AddUntilStep("elapsed greater than zero", () => gameplayClockContainer.GameplayClock.ElapsedFrameTime > 0);
+            AddUntilStep("elapsed greater than zero", () => gameplayClockContainer.ElapsedFrameTime > 0);
         }
 
         [Test]
@@ -60,16 +60,16 @@ namespace osu.Game.Tests.Gameplay
             });
 
             AddStep("start clock", () => gameplayClockContainer.Start());
-            AddUntilStep("current time greater 2000", () => gameplayClockContainer.GameplayClock.CurrentTime > 2000);
+            AddUntilStep("current time greater 2000", () => gameplayClockContainer.CurrentTime > 2000);
 
             double timeAtReset = 0;
             AddStep("reset clock", () =>
             {
-                timeAtReset = gameplayClockContainer.GameplayClock.CurrentTime;
+                timeAtReset = gameplayClockContainer.CurrentTime;
                 gameplayClockContainer.Reset();
             });
 
-            AddAssert("current time < time at reset", () => gameplayClockContainer.GameplayClock.CurrentTime < timeAtReset);
+            AddAssert("current time < time at reset", () => gameplayClockContainer.CurrentTime < timeAtReset);
         }
 
         [Test]

osu.Game.Tests/Gameplay/TestSceneStoryboardSamples.cs

@@ -77,7 +77,6 @@ namespace osu.Game.Tests.Gameplay
 
                 Add(gameplayContainer = new MasterGameplayClockContainer(working, 0)
                 {
-                    IsPaused = { Value = true },
                     Child = new FrameStabilityContainer
                     {
                         Child = sample = new DrawableStoryboardSample(new StoryboardSampleInfo(string.Empty, 0, 1))
@@ -106,7 +105,6 @@ namespace osu.Game.Tests.Gameplay
                 Add(gameplayContainer = new MasterGameplayClockContainer(working, start_time)
                 {
                     StartTime = start_time,
-                    IsPaused = { Value = true },
                     Child = new FrameStabilityContainer
                     {
                         Child = sample = new DrawableStoryboardSample(new StoryboardSampleInfo(string.Empty, 0, 1))
@@ -141,7 +139,7 @@ namespace osu.Game.Tests.Gameplay
 
                 beatmapSkinSourceContainer.Add(sample = new TestDrawableStoryboardSample(new StoryboardSampleInfo("test-sample", 1, 1))
                 {
-                    Clock = gameplayContainer.GameplayClock
+                    Clock = gameplayContainer
                 });
             });
 

osu.Game.Tests/NonVisual/GameplayClockTest.cs

@@ -4,6 +4,7 @@
 #nullable disable
 
 using System.Collections.Generic;
+using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Bindables;
 using osu.Framework.Timing;
@@ -30,7 +31,7 @@ namespace osu.Game.Tests.NonVisual
         {
             public List<Bindable<double>> MutableNonGameplayAdjustments { get; } = new List<Bindable<double>>();
 
-            public override IEnumerable<Bindable<double>> NonGameplayAdjustments => MutableNonGameplayAdjustments;
+            public override IEnumerable<double> NonGameplayAdjustments => MutableNonGameplayAdjustments.Select(b => b.Value);
 
             public TestGameplayClock(IFrameBasedClock underlyingClock)
                 : base(underlyingClock)

osu.Game.Tests/Visual/Gameplay/TestSceneBeatmapSkinFallbacks.cs

@@ -80,7 +80,7 @@ namespace osu.Game.Tests.Visual.Gameplay
                     (typeof(ScoreProcessor), actualComponentsContainer.Dependencies.Get<ScoreProcessor>()),
                     (typeof(HealthProcessor), actualComponentsContainer.Dependencies.Get<HealthProcessor>()),
                     (typeof(GameplayState), actualComponentsContainer.Dependencies.Get<GameplayState>()),
-                    (typeof(GameplayClock), actualComponentsContainer.Dependencies.Get<GameplayClock>())
+                    (typeof(IGameplayClock), actualComponentsContainer.Dependencies.Get<IGameplayClock>())
                 },
             };
 

osu.Game.Tests/Visual/Gameplay/TestSceneFrameStabilityContainer.cs

@@ -137,13 +137,13 @@ namespace osu.Game.Tests.Visual.Gameplay
 
         private void seekManualTo(double time) => AddStep($"seek manual clock to {time}", () => manualClock.CurrentTime = time);
 
-        private void confirmSeek(double time) => AddUntilStep($"wait for seek to {time}", () => consumer.Clock.CurrentTime == time);
+        private void confirmSeek(double time) => AddUntilStep($"wait for seek to {time}", () => consumer.Clock.CurrentTime, () => Is.EqualTo(time));
 
         private void checkFrameCount(int frames) =>
-            AddAssert($"elapsed frames is {frames}", () => consumer.ElapsedFrames == frames);
+            AddAssert($"elapsed frames is {frames}", () => consumer.ElapsedFrames, () => Is.EqualTo(frames));
 
         private void checkRate(double rate) =>
-            AddAssert($"clock rate is {rate}", () => consumer.Clock.Rate == rate);
+            AddAssert($"clock rate is {rate}", () => consumer.Clock.Rate, () => Is.EqualTo(rate));
 
         public class ClockConsumingChild : CompositeDrawable
         {

osu.Game.Tests/Visual/Gameplay/TestSceneGameplaySamplePlayback.cs

@@ -1,8 +1,6 @@
 // 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 disable
-
 using System.Collections.Generic;
 using System.Linq;
 using NUnit.Framework;
@@ -21,22 +19,22 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Test]
         public void TestAllSamplesStopDuringSeek()
         {
-            DrawableSlider slider = null;
+            DrawableSlider? slider = null;
-            PoolableSkinnableSample[] samples = null;
+            PoolableSkinnableSample[] samples = null!;
-            ISamplePlaybackDisabler sampleDisabler = null;
+            ISamplePlaybackDisabler sampleDisabler = null!;
 
             AddUntilStep("get variables", () =>
             {
                 sampleDisabler = Player;
                 slider = Player.ChildrenOfType<DrawableSlider>().MinBy(s => s.HitObject.StartTime);
-                samples = slider?.ChildrenOfType<PoolableSkinnableSample>().ToArray();
+                samples = slider.ChildrenOfType<PoolableSkinnableSample>().ToArray();
 
                 return slider != null;
             });
 
             AddUntilStep("wait for slider sliding then seek", () =>
             {
-                if (!slider.Tracking.Value)
+                if (slider?.Tracking.Value != true)
                     return false;
 
                 if (!samples.Any(s => s.Playing))

osu.Game.Tests/Visual/Gameplay/TestSceneHUDOverlay.cs

@@ -38,8 +38,8 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Cached]
         private GameplayState gameplayState = TestGameplayState.Create(new OsuRuleset());
 
-        [Cached]
+        [Cached(typeof(IGameplayClock))]
-        private readonly GameplayClock gameplayClock = new GameplayClock(new FramedClock());
+        private readonly IGameplayClock gameplayClock = new GameplayClock(new FramedClock());
 
         // best way to check without exposing.
         private Drawable hideTarget => hudOverlay.KeyCounter;

osu.Game.Tests/Visual/Gameplay/TestSceneLeadIn.cs

@@ -130,7 +130,7 @@ namespace osu.Game.Tests.Visual.Gameplay
 
             public double FirstHitObjectTime => DrawableRuleset.Objects.First().StartTime;
 
-            public double GameplayClockTime => GameplayClockContainer.GameplayClock.CurrentTime;
+            public double GameplayClockTime => GameplayClockContainer.CurrentTime;
 
             protected override void UpdateAfterChildren()
             {
@@ -138,7 +138,7 @@ namespace osu.Game.Tests.Visual.Gameplay
 
                 if (!FirstFrameClockTime.HasValue)
                 {
-                    FirstFrameClockTime = GameplayClockContainer.GameplayClock.CurrentTime;
+                    FirstFrameClockTime = GameplayClockContainer.CurrentTime;
                     AddInternal(new OsuSpriteText
                     {
                         Text = $"GameplayStartTime: {DrawableRuleset.GameplayStartTime} "

osu.Game.Tests/Visual/Gameplay/TestSceneOverlayActivation.cs

@@ -19,7 +19,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             base.SetUpSteps();
 
             AddUntilStep("gameplay has started",
-                () => Player.GameplayClockContainer.GameplayClock.CurrentTime > Player.DrawableRuleset.GameplayStartTime);
+                () => Player.GameplayClockContainer.CurrentTime > Player.DrawableRuleset.GameplayStartTime);
         }
 
         [Test]

osu.Game.Tests/Visual/Gameplay/TestScenePause.cs

@@ -313,7 +313,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddUntilStep("pause again", () =>
             {
                 Player.Pause();
-                return !Player.GameplayClockContainer.GameplayClock.IsRunning;
+                return !Player.GameplayClockContainer.IsRunning;
             });
 
             AddAssert("loop is playing", () => getLoop().IsPlaying);
@@ -378,7 +378,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddAssert("pause overlay " + (isShown ? "shown" : "hidden"), () => Player.PauseOverlayVisible == isShown);
 
         private void confirmClockRunning(bool isRunning) =>
-            AddUntilStep("clock " + (isRunning ? "running" : "stopped"), () => Player.GameplayClockContainer.GameplayClock.IsRunning == isRunning);
+            AddUntilStep("clock " + (isRunning ? "running" : "stopped"), () => Player.GameplayClockContainer.IsRunning == isRunning);
 
         protected override bool AllowFail => true;
 

osu.Game.Tests/Visual/Gameplay/TestSceneSkinEditorMultipleSkins.cs

@@ -29,8 +29,8 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Cached]
         private GameplayState gameplayState = TestGameplayState.Create(new OsuRuleset());
 
-        [Cached]
+        [Cached(typeof(IGameplayClock))]
-        private readonly GameplayClock gameplayClock = new GameplayClock(new FramedClock());
+        private readonly IGameplayClock gameplayClock = new GameplayClock(new FramedClock());
 
         [SetUpSteps]
         public void SetUpSteps()

osu.Game.Tests/Visual/Gameplay/TestSceneSkinnableHUDOverlay.cs

@@ -36,8 +36,8 @@ namespace osu.Game.Tests.Visual.Gameplay
         [Cached]
         private GameplayState gameplayState = TestGameplayState.Create(new OsuRuleset());
 
-        [Cached]
+        [Cached(typeof(IGameplayClock))]
-        private readonly GameplayClock gameplayClock = new GameplayClock(new FramedClock());
+        private readonly IGameplayClock gameplayClock = new GameplayClock(new FramedClock());
 
         private IEnumerable<HUDOverlay> hudOverlays => CreatedDrawables.OfType<HUDOverlay>();
 

osu.Game.Tests/Visual/Gameplay/TestSceneSkipOverlay.cs

@@ -6,6 +6,7 @@
 using NUnit.Framework;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
+using osu.Framework.Timing;
 using osu.Game.Rulesets.Osu;
 using osu.Game.Screens.Play;
 using osuTK;
@@ -22,7 +23,7 @@ namespace osu.Game.Tests.Visual.Gameplay
         private double increment;
 
         private GameplayClockContainer gameplayClockContainer;
-        private GameplayClock gameplayClock;
+        private IFrameBasedClock gameplayClock;
 
         private const double skip_time = 6000;
 
@@ -51,7 +52,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             };
 
             gameplayClockContainer.Start();
-            gameplayClock = gameplayClockContainer.GameplayClock;
+            gameplayClock = gameplayClockContainer;
         });
 
         [Test]

osu.Game.Tests/Visual/Gameplay/TestSceneSongProgress.cs

@@ -30,7 +30,7 @@ namespace osu.Game.Tests.Visual.Gameplay
 
             Add(gameplayClockContainer = new MasterGameplayClockContainer(Beatmap.Value, skip_target_time));
 
-            Dependencies.CacheAs(gameplayClockContainer.GameplayClock);
+            Dependencies.CacheAs<IGameplayClock>(gameplayClockContainer);
         }
 
         [SetUpSteps]

osu.Game.Tests/Visual/Gameplay/TestSceneSpectator.cs

@@ -363,7 +363,7 @@ namespace osu.Game.Tests.Visual.Gameplay
         private Player player => Stack.CurrentScreen as Player;
 
         private double currentFrameStableTime
-            => player.ChildrenOfType<FrameStabilityContainer>().First().FrameStableClock.CurrentTime;
+            => player.ChildrenOfType<FrameStabilityContainer>().First().CurrentTime;
 
         private void waitForPlayer() => AddUntilStep("wait for player", () => (Stack.CurrentScreen as Player)?.IsLoaded == true);
 

osu.Game.Tests/Visual/Gameplay/TestSceneStoryboardWithOutro.cs

@@ -64,7 +64,7 @@ namespace osu.Game.Tests.Visual.Gameplay
         public void TestStoryboardNoSkipOutro()
         {
             CreateTest();
-            AddUntilStep("storyboard ends", () => Player.GameplayClockContainer.GameplayClock.CurrentTime >= currentStoryboardDuration);
+            AddUntilStep("storyboard ends", () => Player.GameplayClockContainer.CurrentTime >= currentStoryboardDuration);
             AddUntilStep("wait for score shown", () => Player.IsScoreShown);
         }
 
@@ -100,7 +100,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             });
 
             AddUntilStep("wait for fail", () => Player.GameplayState.HasFailed);
-            AddUntilStep("storyboard ends", () => Player.GameplayClockContainer.GameplayClock.CurrentTime >= currentStoryboardDuration);
+            AddUntilStep("storyboard ends", () => Player.GameplayClockContainer.CurrentTime >= currentStoryboardDuration);
             AddUntilStep("wait for fail overlay", () => Player.FailOverlay.State.Value == Visibility.Visible);
         }
 
@@ -111,7 +111,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             {
                 AddStep("set ShowResults = false", () => showResults = false);
             });
-            AddUntilStep("storyboard ends", () => Player.GameplayClockContainer.GameplayClock.CurrentTime >= currentStoryboardDuration);
+            AddUntilStep("storyboard ends", () => Player.GameplayClockContainer.CurrentTime >= currentStoryboardDuration);
             AddWaitStep("wait", 10);
             AddAssert("no score shown", () => !Player.IsScoreShown);
         }
@@ -120,7 +120,7 @@ namespace osu.Game.Tests.Visual.Gameplay
         public void TestStoryboardEndsBeforeCompletion()
         {
             CreateTest(() => AddStep("set storyboard duration to .1s", () => currentStoryboardDuration = 100));
-            AddUntilStep("storyboard ends", () => Player.GameplayClockContainer.GameplayClock.CurrentTime >= currentStoryboardDuration);
+            AddUntilStep("storyboard ends", () => Player.GameplayClockContainer.CurrentTime >= currentStoryboardDuration);
             AddUntilStep("completion set by processor", () => Player.ScoreProcessor.HasCompleted.Value);
             AddUntilStep("wait for score shown", () => Player.IsScoreShown);
         }
@@ -138,7 +138,7 @@ namespace osu.Game.Tests.Visual.Gameplay
             AddUntilStep("skip overlay content not visible", () => fadeContainer().State == Visibility.Hidden);
 
             AddUntilStep("skip overlay content becomes visible", () => fadeContainer().State == Visibility.Visible);
-            AddUntilStep("storyboard ends", () => Player.GameplayClockContainer.GameplayClock.CurrentTime >= currentStoryboardDuration);
+            AddUntilStep("storyboard ends", () => Player.GameplayClockContainer.CurrentTime >= currentStoryboardDuration);
         }
 
         [Test]

osu.Game.Tests/Visual/Multiplayer/TestSceneMultiSpectatorScreen.cs

@@ -451,7 +451,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
         }
 
         private void checkPaused(int userId, bool state)
-            => AddUntilStep($"{userId} is {(state ? "paused" : "playing")}", () => getPlayer(userId).ChildrenOfType<GameplayClockContainer>().First().GameplayClock.IsRunning != state);
+            => AddUntilStep($"{userId} is {(state ? "paused" : "playing")}", () => getPlayer(userId).ChildrenOfType<GameplayClockContainer>().First().IsRunning != state);
 
         private void checkPausedInstant(int userId, bool state)
         {

osu.Game.Tests/Visual/Multiplayer/TestSceneMultiplayer.cs

@@ -671,7 +671,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             for (double i = 1000; i < TestResources.QUICK_BEATMAP_LENGTH; i += 1000)
             {
                 double time = i;
-                AddUntilStep($"wait for time > {i}", () => this.ChildrenOfType<GameplayClockContainer>().SingleOrDefault()?.GameplayClock.CurrentTime > time);
+                AddUntilStep($"wait for time > {i}", () => this.ChildrenOfType<GameplayClockContainer>().SingleOrDefault()?.CurrentTime > time);
             }
 
             AddUntilStep("wait for results", () => multiplayerComponents.CurrentScreen is ResultsScreen);

osu.Game/Rulesets/UI/DrawableRuleset.cs

@@ -67,7 +67,7 @@ namespace osu.Game.Rulesets.UI
 
         public override Container FrameStableComponents { get; } = new Container { RelativeSizeAxes = Axes.Both };
 
-        public override IFrameStableClock FrameStableClock => frameStabilityContainer.FrameStableClock;
+        public override IFrameStableClock FrameStableClock => frameStabilityContainer;
 
         private bool frameStablePlayback = true;
 

osu.Game/Rulesets/UI/FrameStabilityContainer.cs

@@ -1,16 +1,16 @@
 // 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 disable
-
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Timing;
+using osu.Framework.Utils;
 using osu.Game.Input.Handlers;
 using osu.Game.Screens.Play;
 
@@ -20,9 +20,11 @@ namespace osu.Game.Rulesets.UI
     /// A container which consumes a parent gameplay clock and standardises frame counts for children.
     /// Will ensure a minimum of 50 frames per clock second is maintained, regardless of any system lag or seeks.
     /// </summary>
-    public class FrameStabilityContainer : Container, IHasReplayHandler
+    [Cached(typeof(IGameplayClock))]
+    [Cached(typeof(IFrameStableClock))]
+    public sealed class FrameStabilityContainer : Container, IHasReplayHandler, IFrameStableClock, IGameplayClock
     {
-        private readonly double gameplayStartTime;
+        public ReplayInputHandler? ReplayInputHandler { get; set; }
 
         /// <summary>
         /// The number of frames (per parent frame) which can be run in an attempt to catch-up to real-time.
@@ -32,28 +34,35 @@ namespace osu.Game.Rulesets.UI
         /// <summary>
         /// Whether to enable frame-stable playback.
         /// </summary>
-        internal bool FrameStablePlayback = true;
+        internal bool FrameStablePlayback { get; set; } = true;
 
-        public IFrameStableClock FrameStableClock => frameStableClock;
+        protected override bool RequiresChildrenUpdate => base.RequiresChildrenUpdate && state != PlaybackState.NotValid;
 
-        [Cached(typeof(GameplayClock))]
+        private readonly Bindable<bool> isCatchingUp = new Bindable<bool>();
-        private readonly FrameStabilityClock frameStableClock;
 
-        public FrameStabilityContainer(double gameplayStartTime = double.MinValue)
+        private readonly Bindable<bool> waitingOnFrames = new Bindable<bool>();
-        {
-            RelativeSizeAxes = Axes.Both;
 
-            frameStableClock = new FrameStabilityClock(framedClock = new FramedClock(manualClock = new ManualClock()));
+        private readonly double gameplayStartTime;
 
-            this.gameplayStartTime = gameplayStartTime;
+        private IGameplayClock? parentGameplayClock;
-        }
 
+        /// <summary>
+        /// A clock which is used as reference for time, rate and running state.
+        /// </summary>
+        private IClock referenceClock = null!;
+
+        /// <summary>
+        /// A local manual clock which tracks the reference clock.
+        /// Values are transferred from <see cref="referenceClock"/> each update call.
+        /// </summary>
         private readonly ManualClock manualClock;
 
+        /// <summary>
+        /// The main framed clock which has stability applied to it.
+        /// This gets exposed to children as an <see cref="IGameplayClock"/>.
+        /// </summary>
         private readonly FramedClock framedClock;
 
-        private IFrameBasedClock parentGameplayClock;
-
         /// <summary>
         /// The current direction of playback to be exposed to frame stable children.
         /// </summary>
@@ -62,32 +71,34 @@ namespace osu.Game.Rulesets.UI
         /// </remarks>
         private int direction = 1;
 
-        [BackgroundDependencyLoader(true)]
-        private void load(GameplayClock clock)
-        {
-            if (clock != null)
-            {
-                parentGameplayClock = frameStableClock.ParentGameplayClock = clock;
-                frameStableClock.IsPaused.BindTo(clock.IsPaused);
-            }
-        }
-
-        protected override void LoadComplete()
-        {
-            base.LoadComplete();
-            setClock();
-        }
-
         private PlaybackState state;
 
-        protected override bool RequiresChildrenUpdate => base.RequiresChildrenUpdate && state != PlaybackState.NotValid;
-
         private bool hasReplayAttached => ReplayInputHandler != null;
 
-        private const double sixty_frame_time = 1000.0 / 60;
-
         private bool firstConsumption = true;
 
+        public FrameStabilityContainer(double gameplayStartTime = double.MinValue)
+        {
+            RelativeSizeAxes = Axes.Both;
+
+            framedClock = new FramedClock(manualClock = new ManualClock());
+
+            this.gameplayStartTime = gameplayStartTime;
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(IGameplayClock? gameplayClock)
+        {
+            if (gameplayClock != null)
+            {
+                parentGameplayClock = gameplayClock;
+                IsPaused.BindTo(parentGameplayClock.IsPaused);
+            }
+
+            referenceClock = gameplayClock ?? Clock;
+            Clock = this;
+        }
+
         public override bool UpdateSubTree()
         {
             int loops = MaxCatchUpFrames;
@@ -110,12 +121,12 @@ namespace osu.Game.Rulesets.UI
 
         private void updateClock()
         {
-            if (frameStableClock.WaitingOnFrames.Value)
+            if (waitingOnFrames.Value)
             {
                 // if waiting on frames, run one update loop to determine if frames have arrived.
                 state = PlaybackState.Valid;
             }
-            else if (frameStableClock.IsPaused.Value)
+            else if (IsPaused.Value)
             {
                 // time should not advance while paused, nor should anything run.
                 state = PlaybackState.NotValid;
@@ -126,10 +137,7 @@ namespace osu.Game.Rulesets.UI
                 state = PlaybackState.Valid;
             }
 
-            if (parentGameplayClock == null)
+            double proposedTime = referenceClock.CurrentTime;
-                setClock(); // LoadComplete may not be run yet, but we still want the clock.
-
-            double proposedTime = parentGameplayClock.CurrentTime;
 
             if (FrameStablePlayback)
                 // if we require frame stability, the proposed time will be adjusted to move at most one known
@@ -149,14 +157,14 @@ namespace osu.Game.Rulesets.UI
             if (state == PlaybackState.Valid && proposedTime != manualClock.CurrentTime)
                 direction = proposedTime >= manualClock.CurrentTime ? 1 : -1;
 
-            double timeBehind = Math.Abs(proposedTime - parentGameplayClock.CurrentTime);
+            double timeBehind = Math.Abs(proposedTime - referenceClock.CurrentTime);
 
-            frameStableClock.IsCatchingUp.Value = timeBehind > 200;
+            isCatchingUp.Value = timeBehind > 200;
-            frameStableClock.WaitingOnFrames.Value = state == PlaybackState.NotValid;
+            waitingOnFrames.Value = state == PlaybackState.NotValid;
 
             manualClock.CurrentTime = proposedTime;
-            manualClock.Rate = Math.Abs(parentGameplayClock.Rate) * direction;
+            manualClock.Rate = Math.Abs(referenceClock.Rate) * direction;
-            manualClock.IsRunning = parentGameplayClock.IsRunning;
+            manualClock.IsRunning = referenceClock.IsRunning;
 
             // determine whether catch-up is required.
             if (state == PlaybackState.Valid && timeBehind > 0)
@@ -174,6 +182,8 @@ namespace osu.Game.Rulesets.UI
         /// <returns>Whether playback is still valid.</returns>
         private bool updateReplay(ref double proposedTime)
         {
+            Debug.Assert(ReplayInputHandler != null);
+
             double? newTime;
 
             if (FrameStablePlayback)
@@ -210,6 +220,8 @@ namespace osu.Game.Rulesets.UI
         /// <param name="proposedTime">The time which is to be displayed.</param>
         private void applyFrameStability(ref double proposedTime)
         {
+            const double sixty_frame_time = 1000.0 / 60;
+
             if (firstConsumption)
             {
                 // On the first update, frame-stability seeking would result in unexpected/unwanted behaviour.
@@ -233,20 +245,54 @@ namespace osu.Game.Rulesets.UI
             }
         }
 
-        private void setClock()
+        #region Delegation of IGameplayClock
+
+        public IBindable<bool> IsPaused { get; } = new BindableBool();
+
+        public double CurrentTime => framedClock.CurrentTime;
+
+        public double Rate => framedClock.Rate;
+
+        public bool IsRunning => framedClock.IsRunning;
+
+        public void ProcessFrame() { }
+
+        public double ElapsedFrameTime => framedClock.ElapsedFrameTime;
+
+        public double FramesPerSecond => framedClock.FramesPerSecond;
+
+        public FrameTimeInfo TimeInfo => framedClock.TimeInfo;
+
+        public double TrueGameplayRate
         {
-            if (parentGameplayClock == null)
+            get
             {
-                // in case a parent gameplay clock isn't available, just use the parent clock.
+                double baseRate = Rate;
-                parentGameplayClock ??= Clock;
+
-            }
+                foreach (double adjustment in NonGameplayAdjustments)
-            else
+                {
-            {
+                    if (Precision.AlmostEquals(adjustment, 0))
-                Clock = frameStableClock;
+                        return 0;
+
+                    baseRate /= adjustment;
+                }
+
+                return baseRate;
             }
         }
 
-        public ReplayInputHandler ReplayInputHandler { get; set; }
+        public double? StartTime => parentGameplayClock?.StartTime;
+
+        public IEnumerable<double> NonGameplayAdjustments => parentGameplayClock?.NonGameplayAdjustments ?? Enumerable.Empty<double>();
+
+        #endregion
+
+        #region Delegation of IFrameStableClock
+
+        IBindable<bool> IFrameStableClock.IsCatchingUp => isCatchingUp;
+        IBindable<bool> IFrameStableClock.WaitingOnFrames => waitingOnFrames;
+
+        #endregion
 
         private enum PlaybackState
         {
@@ -266,25 +312,5 @@ namespace osu.Game.Rulesets.UI
             /// </summary>
             Valid
         }
-
-        private class FrameStabilityClock : GameplayClock, IFrameStableClock
-        {
-            public GameplayClock ParentGameplayClock;
-
-            public readonly Bindable<bool> IsCatchingUp = new Bindable<bool>();
-
-            public readonly Bindable<bool> WaitingOnFrames = new Bindable<bool>();
-
-            public override IEnumerable<Bindable<double>> NonGameplayAdjustments => ParentGameplayClock?.NonGameplayAdjustments ?? Enumerable.Empty<Bindable<double>>();
-
-            public FrameStabilityClock(FramedClock underlyingClock)
-                : base(underlyingClock)
-            {
-            }
-
-            IBindable<bool> IFrameStableClock.IsCatchingUp => IsCatchingUp;
-
-            IBindable<bool> IFrameStableClock.WaitingOnFrames => WaitingOnFrames;
-        }
     }
 }

osu.Game/Rulesets/UI/IFrameStableClock.cs

@@ -1,8 +1,6 @@
 // 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 disable
-
 using osu.Framework.Bindables;
 using osu.Framework.Timing;
 

osu.Game/Screens/OnlinePlay/Multiplayer/Spectate/MultiSpectatorPlayer.cs

@@ -1,12 +1,8 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-#nullable disable
-
-using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
-using osu.Framework.Timing;
 using osu.Game.Beatmaps;
 using osu.Game.Scoring;
 using osu.Game.Screens.Play;
@@ -26,7 +22,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Spectate
         /// </summary>
         /// <param name="score">The score containing the player's replay.</param>
         /// <param name="spectatorPlayerClock">The clock controlling the gameplay running state.</param>
-        public MultiSpectatorPlayer([NotNull] Score score, [NotNull] ISpectatorPlayerClock spectatorPlayerClock)
+        public MultiSpectatorPlayer(Score score, ISpectatorPlayerClock spectatorPlayerClock)
             : base(score, new PlayerConfiguration { AllowUserInteraction = false })
         {
             this.spectatorPlayerClock = spectatorPlayerClock;
@@ -41,6 +37,19 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Spectate
             HUDOverlay.HoldToQuit.Expire();
         }
 
+        protected override void Update()
+        {
+            // The player clock's running state is controlled externally, but the local pausing state needs to be updated to start/stop gameplay.
+            CatchUpSpectatorPlayerClock catchUpClock = (CatchUpSpectatorPlayerClock)GameplayClockContainer.SourceClock;
+
+            if (catchUpClock.IsRunning)
+                GameplayClockContainer.Start();
+            else
+                GameplayClockContainer.Stop();
+
+            base.Update();
+        }
+
         protected override void UpdateAfterChildren()
         {
             base.UpdateAfterChildren();
@@ -50,28 +59,6 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Spectate
         }
 
         protected override GameplayClockContainer CreateGameplayClockContainer(WorkingBeatmap beatmap, double gameplayStart)
-            => new SpectatorGameplayClockContainer(spectatorPlayerClock);
+            => new GameplayClockContainer(spectatorPlayerClock);
-
-        private class SpectatorGameplayClockContainer : GameplayClockContainer
-        {
-            public SpectatorGameplayClockContainer([NotNull] IClock sourceClock)
-                : base(sourceClock)
-            {
-            }
-
-            protected override void Update()
-            {
-                // The SourceClock here is always a CatchUpSpectatorPlayerClock.
-                // The player clock's running state is controlled externally, but the local pausing state needs to be updated to stop gameplay.
-                if (SourceClock.IsRunning)
-                    Start();
-                else
-                    Stop();
-
-                base.Update();
-            }
-
-            protected override GameplayClock CreateGameplayClock(IFrameBasedClock source) => new GameplayClock(source);
-        }
     }
 }

osu.Game/Screens/OnlinePlay/Multiplayer/Spectate/MultiSpectatorScreen.cs

@@ -126,7 +126,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Spectate
 
             for (int i = 0; i < Users.Count; i++)
             {
-                grid.Add(instances[i] = new PlayerArea(Users[i], masterClockContainer.GameplayClock));
+                grid.Add(instances[i] = new PlayerArea(Users[i], masterClockContainer));
                 syncManager.AddPlayerClock(instances[i].GameplayClock);
             }
 

osu.Game/Screens/Play/ComboEffects.cs

@@ -45,7 +45,7 @@ namespace osu.Game.Screens.Play
         private ISamplePlaybackDisabler samplePlaybackDisabler { get; set; }
 
         [Resolved]
-        private GameplayClock gameplayClock { get; set; }
+        private IGameplayClock gameplayClock { get; set; }
 
         private void onComboChange(ValueChangedEvent<int> combo)
         {

osu.Game/Screens/Play/GameplayClock.cs

@@ -19,51 +19,39 @@ namespace osu.Game.Screens.Play
     /// <see cref="IFrameBasedClock"/>, as this should only be done once to ensure accuracy.
     /// </remarks>
     /// </summary>
-    public class GameplayClock : IFrameBasedClock
+    public class GameplayClock : IGameplayClock
     {
         internal readonly IFrameBasedClock UnderlyingClock;
 
         public readonly BindableBool IsPaused = new BindableBool();
 
-        /// <summary>
+        IBindable<bool> IGameplayClock.IsPaused => IsPaused;
-        /// All adjustments applied to this clock which don't come from gameplay or mods.
+
-        /// </summary>
+        public virtual IEnumerable<double> NonGameplayAdjustments => Enumerable.Empty<double>();
-        public virtual IEnumerable<Bindable<double>> NonGameplayAdjustments => Enumerable.Empty<Bindable<double>>();
 
         public GameplayClock(IFrameBasedClock underlyingClock)
         {
             UnderlyingClock = underlyingClock;
         }
 
-        /// <summary>
-        /// The time from which the clock should start. Will be seeked to on calling <see cref="GameplayClockContainer.Reset"/>.
-        /// </summary>
-        /// <remarks>
-        /// If not set, a value of zero will be used.
-        /// Importantly, the value will be inferred from the current ruleset in <see cref="MasterGameplayClockContainer"/> unless specified.
-        /// </remarks>
         public double? StartTime { get; internal set; }
 
         public double CurrentTime => UnderlyingClock.CurrentTime;
 
         public double Rate => UnderlyingClock.Rate;
 
-        /// <summary>
-        /// The rate of gameplay when playback is at 100%.
-        /// This excludes any seeking / user adjustments.
-        /// </summary>
         public double TrueGameplayRate
         {
             get
             {
                 double baseRate = Rate;
 
-                foreach (var adjustment in NonGameplayAdjustments)
+                foreach (double adjustment in NonGameplayAdjustments)
                 {
-                    if (Precision.AlmostEquals(adjustment.Value, 0))
+                    if (Precision.AlmostEquals(adjustment, 0))
                         return 0;
 
-                    baseRate /= adjustment.Value;
+                    baseRate /= adjustment;
                 }
 
                 return baseRate;

osu.Game/Screens/Play/GameplayClockContainer.cs

@@ -1,11 +1,11 @@
 // 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 disable
-
 using System;
+using System.Collections.Generic;
 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.Logging;
@@ -16,17 +16,14 @@ namespace osu.Game.Screens.Play
     /// <summary>
     /// Encapsulates gameplay timing logic and provides a <see cref="GameplayClock"/> via DI for gameplay components to use.
     /// </summary>
-    public abstract class GameplayClockContainer : Container, IAdjustableClock
+    public class GameplayClockContainer : Container, IAdjustableClock, IGameplayClock
     {
-        /// <summary>
-        /// The final clock which is exposed to gameplay components.
-        /// </summary>
-        public GameplayClock GameplayClock { get; private set; }
-
         /// <summary>
         /// Whether gameplay is paused.
         /// </summary>
-        public readonly BindableBool IsPaused = new BindableBool(true);
+        public IBindable<bool> IsPaused => isPaused;
+
+        private readonly BindableBool isPaused = new BindableBool(true);
 
         /// <summary>
         /// The adjustable source clock used for gameplay. Should be used for seeks and clock control.
@@ -36,12 +33,12 @@ namespace osu.Game.Screens.Play
         /// <summary>
         /// The source clock.
         /// </summary>
-        protected IClock SourceClock { get; private set; }
+        public IClock SourceClock { get; private set; }
 
         /// <summary>
         /// Invoked when a seek has been performed via <see cref="Seek"/>
         /// </summary>
-        public event Action OnSeek;
+        public event Action? OnSeek;
 
         private double? startTime;
 
@@ -59,16 +56,23 @@ namespace osu.Game.Screens.Play
             {
                 startTime = value;
 
-                if (GameplayClock != null)
+                if (GameplayClock.IsNotNull())
                     GameplayClock.StartTime = value;
             }
         }
 
+        public IEnumerable<double> NonGameplayAdjustments => GameplayClock.NonGameplayAdjustments;
+
+        /// <summary>
+        /// The final clock which is exposed to gameplay components.
+        /// </summary>
+        protected GameplayClock GameplayClock { get; private set; } = null!;
+
         /// <summary>
         /// Creates a new <see cref="GameplayClockContainer"/>.
         /// </summary>
         /// <param name="sourceClock">The source <see cref="IClock"/> used for timing.</param>
-        protected GameplayClockContainer(IClock sourceClock)
+        public GameplayClockContainer(IClock sourceClock)
         {
             SourceClock = sourceClock;
 
@@ -82,10 +86,12 @@ namespace osu.Game.Screens.Play
         {
             var dependencies = new DependencyContainer(base.CreateChildDependencies(parent));
 
-            dependencies.CacheAs(GameplayClock = CreateGameplayClock(AdjustableSource));
+            GameplayClock = CreateGameplayClock(AdjustableSource);
+
+            dependencies.CacheAs<IGameplayClock>(this);
 
             GameplayClock.StartTime = StartTime;
-            GameplayClock.IsPaused.BindTo(IsPaused);
+            GameplayClock.IsPaused.BindTo(isPaused);
 
             return dependencies;
         }
@@ -106,7 +112,7 @@ namespace osu.Game.Screens.Play
                 AdjustableSource.Start();
             }
 
-            IsPaused.Value = false;
+            isPaused.Value = false;
         }
 
         /// <summary>
@@ -128,7 +134,7 @@ namespace osu.Game.Screens.Play
         /// <summary>
         /// Stops gameplay.
         /// </summary>
-        public void Stop() => IsPaused.Value = true;
+        public void Stop() => isPaused.Value = true;
 
         /// <summary>
         /// Resets this <see cref="GameplayClockContainer"/> and the source to an initial state ready for gameplay.
@@ -193,7 +199,7 @@ namespace osu.Game.Screens.Play
         /// </remarks>
         /// <param name="source">The <see cref="IFrameBasedClock"/> providing the source time.</param>
         /// <returns>The final <see cref="GameplayClock"/>.</returns>
-        protected abstract GameplayClock CreateGameplayClock(IFrameBasedClock source);
+        protected virtual GameplayClock CreateGameplayClock(IFrameBasedClock source) => new GameplayClock(source);
 
         #region IAdjustableClock
 
@@ -205,9 +211,7 @@ namespace osu.Game.Screens.Play
 
         void IAdjustableClock.Reset() => Reset();
 
-        public void ResetSpeedAdjustments()
+        public void ResetSpeedAdjustments() => throw new NotImplementedException();
-        {
-        }
 
         double IAdjustableClock.Rate
         {
@@ -215,12 +219,25 @@ namespace osu.Game.Screens.Play
             set => throw new NotSupportedException();
         }
 
-        double IClock.Rate => GameplayClock.Rate;
+        public double Rate => GameplayClock.Rate;
 
         public double CurrentTime => GameplayClock.CurrentTime;
 
         public bool IsRunning => GameplayClock.IsRunning;
 
         #endregion
+
+        public void ProcessFrame()
+        {
+            // Handled via update. Don't process here to safeguard from external usages potentially processing frames additional times.
+        }
+
+        public double ElapsedFrameTime => GameplayClock.ElapsedFrameTime;
+
+        public double FramesPerSecond => GameplayClock.FramesPerSecond;
+
+        public FrameTimeInfo TimeInfo => GameplayClock.TimeInfo;
+
+        public double TrueGameplayRate => GameplayClock.TrueGameplayRate;
     }
 }

osu.Game/Screens/Play/HUD/SongProgress.cs

@@ -23,7 +23,7 @@ namespace osu.Game.Screens.Play.HUD
         public bool UsesFixedAnchor { get; set; }
 
         [Resolved]
-        protected GameplayClock GameplayClock { get; private set; } = null!;
+        protected IGameplayClock GameplayClock { get; private set; } = null!;
 
         [Resolved(canBeNull: true)]
         private DrawableRuleset? drawableRuleset { get; set; }

osu.Game/Screens/Play/HUD/SongProgressInfo.cs

@@ -38,10 +38,10 @@ namespace osu.Game.Screens.Play.HUD
             set => endTime = value;
         }
 
-        private GameplayClock gameplayClock;
+        private IGameplayClock gameplayClock;
 
         [BackgroundDependencyLoader(true)]
-        private void load(OsuColour colours, GameplayClock clock)
+        private void load(OsuColour colours, IGameplayClock clock)
         {
             if (clock != null)
                 gameplayClock = clock;

osu.Game/Screens/Play/IGameplayClock.cs

@@ -0,0 +1,34 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.Collections.Generic;
+using osu.Framework.Bindables;
+using osu.Framework.Timing;
+
+namespace osu.Game.Screens.Play
+{
+    public interface IGameplayClock : IFrameBasedClock
+    {
+        /// <summary>
+        /// The rate of gameplay when playback is at 100%.
+        /// This excludes any seeking / user adjustments.
+        /// </summary>
+        double TrueGameplayRate { get; }
+
+        /// <summary>
+        /// The time from which the clock should start. Will be seeked to on calling <see cref="GameplayClockContainer.Reset"/>.
+        /// </summary>
+        /// <remarks>
+        /// If not set, a value of zero will be used.
+        /// Importantly, the value will be inferred from the current ruleset in <see cref="MasterGameplayClockContainer"/> unless specified.
+        /// </remarks>
+        double? StartTime { get; }
+
+        /// <summary>
+        /// All adjustments applied to this clock which don't come from gameplay or mods.
+        /// </summary>
+        IEnumerable<double> NonGameplayAdjustments { get; }
+
+        IBindable<bool> IsPaused { get; }
+    }
+}

osu.Game/Screens/Play/MasterGameplayClockContainer.cs

@@ -303,7 +303,7 @@ namespace osu.Game.Screens.Play
         private class MasterGameplayClock : GameplayClock
         {
             public readonly List<Bindable<double>> MutableNonGameplayAdjustments = new List<Bindable<double>>();
-            public override IEnumerable<Bindable<double>> NonGameplayAdjustments => MutableNonGameplayAdjustments;
+            public override IEnumerable<double> NonGameplayAdjustments => MutableNonGameplayAdjustments.Select(b => b.Value);
 
             public MasterGameplayClock(FramedOffsetClock underlyingClock)
                 : base(underlyingClock)

osu.Game/Screens/Play/Player.cs

@@ -330,7 +330,7 @@ namespace osu.Game.Screens.Play
             DrawableRuleset.HasReplayLoaded.BindValueChanged(_ => updateGameplayState());
 
             // bind clock into components that require it
-            DrawableRuleset.IsPaused.BindTo(GameplayClockContainer.IsPaused);
+            ((IBindable<bool>)DrawableRuleset.IsPaused).BindTo(GameplayClockContainer.IsPaused);
 
             DrawableRuleset.NewResult += r =>
             {
@@ -475,7 +475,7 @@ namespace osu.Game.Screens.Play
 
         private void updateSampleDisabledState()
         {
-            samplePlaybackDisabled.Value = DrawableRuleset.FrameStableClock.IsCatchingUp.Value || GameplayClockContainer.GameplayClock.IsPaused.Value;
+            samplePlaybackDisabled.Value = DrawableRuleset.FrameStableClock.IsCatchingUp.Value || GameplayClockContainer.IsPaused.Value;
         }
 
         private void updatePauseOnFocusLostState()
@@ -877,7 +877,7 @@ namespace osu.Game.Screens.Play
         private double? lastPauseActionTime;
 
         protected bool PauseCooldownActive =>
-            lastPauseActionTime.HasValue && GameplayClockContainer.GameplayClock.CurrentTime < lastPauseActionTime + pause_cooldown;
+            lastPauseActionTime.HasValue && GameplayClockContainer.CurrentTime < lastPauseActionTime + pause_cooldown;
 
         /// <summary>
         /// A set of conditionals which defines whether the current game state and configuration allows for
@@ -915,7 +915,7 @@ namespace osu.Game.Screens.Play
 
             GameplayClockContainer.Stop();
             PauseOverlay.Show();
-            lastPauseActionTime = GameplayClockContainer.GameplayClock.CurrentTime;
+            lastPauseActionTime = GameplayClockContainer.CurrentTime;
             return true;
         }
 
@@ -1005,7 +1005,7 @@ namespace osu.Game.Screens.Play
         /// </summary>
         protected virtual void StartGameplay()
         {
-            if (GameplayClockContainer.GameplayClock.IsRunning)
+            if (GameplayClockContainer.IsRunning)
                 throw new InvalidOperationException($"{nameof(StartGameplay)} should not be called when the gameplay clock is already running");
 
             GameplayClockContainer.Reset(true);

osu.Game/Screens/Play/ScreenSuspensionHandler.cs

@@ -18,7 +18,7 @@ namespace osu.Game.Screens.Play
     public class ScreenSuspensionHandler : Component
     {
         private readonly GameplayClockContainer gameplayClockContainer;
-        private Bindable<bool> isPaused;
+        private IBindable<bool> isPaused;
 
         private readonly Bindable<bool> disableSuspensionBindable = new Bindable<bool>();
 

osu.Game/Screens/Play/SkipOverlay.cs

@@ -41,7 +41,7 @@ namespace osu.Game.Screens.Play
         private bool isClickable;
 
         [Resolved]
-        private GameplayClock gameplayClock { get; set; }
+        private IGameplayClock gameplayClock { get; set; }
 
         public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => true;
 

osu.Game/Storyboards/Drawables/DrawableStoryboard.cs

@@ -85,7 +85,7 @@ namespace osu.Game.Storyboards.Drawables
         }
 
         [BackgroundDependencyLoader(true)]
-        private void load(GameplayClock clock, CancellationToken? cancellationToken, GameHost host, RealmAccess realm)
+        private void load(IGameplayClock clock, CancellationToken? cancellationToken, GameHost host, RealmAccess realm)
         {
             if (clock != null)
                 Clock = clock;