Cache IFrameStableClock in Player for easier access

Allows directly referencing rather than going through `DrawableRuleset`.
Helps with testing and implementation of the new song progress display
(ppy#22144).

osu.Game/Screens/Play/HUD/ClicksPerSecond/ClicksPerSecondCalculator.cs

@@ -15,14 +15,12 @@ public partial class ClicksPerSecondCalculator : Component
         [Resolved]
         private IGameplayClock gameplayClock { get; set; } = null!;
 
-        [Resolved(canBeNull: true)]
-        private DrawableRuleset? drawableRuleset { get; set; }
+        [Resolved]
+        private IFrameStableClock? frameStableClock { get; set; }
 
         public int Value { get; private set; }
 
-        // Even though `FrameStabilityContainer` caches as a `GameplayClock`, we need to check it directly via `drawableRuleset`
-        // as this calculator is not contained within the `FrameStabilityContainer` and won't see the dependency.
-        private IGameplayClock clock => drawableRuleset?.FrameStableClock ?? gameplayClock;
+        private IGameplayClock clock => frameStableClock ?? gameplayClock;
 
         public ClicksPerSecondCalculator()
         {

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

@@ -25,10 +25,15 @@ public abstract partial class SongProgress : OverlayContainer, ISkinnableDrawabl
         [Resolved]
         protected IGameplayClock GameplayClock { get; private set; } = null!;
 
-        [Resolved(canBeNull: true)]
-        private DrawableRuleset? drawableRuleset { get; set; }
+        [Resolved]
+        private IFrameStableClock? frameStableClock { get; set; }
+
+        /// <summary>
+        /// The reference clock is used to accurately tell the current playfield's time (including catch-up lag).
+        /// However, if none is available (i.e. used in tests), we fall back to the gameplay clock.
+        /// </summary>
+        protected IClock FrameStableClock => frameStableClock ?? GameplayClock;
 
-        private IClock? referenceClock;
         private IEnumerable<HitObject>? objects;
 
         public IEnumerable<HitObject> Objects
@@ -58,12 +63,11 @@ protected override void LoadComplete()
         protected virtual void UpdateObjects(IEnumerable<HitObject> objects) { }
 
         [BackgroundDependencyLoader]
-        private void load()
+        private void load(DrawableRuleset? drawableRuleset)
         {
             if (drawableRuleset != null)
             {
                 Objects = drawableRuleset.Objects;
-                referenceClock = drawableRuleset.FrameStableClock;
             }
         }
 
@@ -74,9 +78,7 @@ protected override void Update()
             if (objects == null)
                 return;
 
-            // The reference clock is used to accurately tell the playfield's time. This is obtained from the drawable ruleset.
-            // However, if no drawable ruleset is available (i.e. used in tests), we fall back to the gameplay clock.
-            double currentTime = referenceClock?.CurrentTime ?? GameplayClock.CurrentTime;
+            double currentTime = FrameStableClock.CurrentTime;
 
             bool isInIntro = currentTime < FirstHitTime;
 

osu.Game/Screens/Play/Player.cs

@@ -225,6 +225,7 @@ private void load(AudioManager audio, OsuConfigManager config, OsuGameBase game,
 
             DrawableRuleset = ruleset.CreateDrawableRulesetWith(playableBeatmap, gameplayMods);
             dependencies.CacheAs(DrawableRuleset);
+            dependencies.CacheAs(DrawableRuleset.FrameStableClock);
 
             ScoreProcessor = ruleset.CreateScoreProcessor();
             ScoreProcessor.Mods.Value = gameplayMods;