Move catcher trail generation logic to CatcherArea

osu.Game.Rulesets.Catch.Tests/TestSceneCatchSkinConfiguration.cs

@@ -41,7 +41,7 @@ namespace osu.Game.Rulesets.Catch.Tests
                 var skin = new TestSkin { FlipCatcherPlate = flip };
                 container.Child = new SkinProvidingContainer(skin)
                 {
-                    Child = catcher = new Catcher(new CatcherTrailDisplay(), new DroppedObjectContainer())
+                    Child = catcher = new Catcher(new DroppedObjectContainer())
                     {
                         Anchor = Anchor.Centre
                     }

osu.Game.Rulesets.Catch.Tests/TestSceneCatcher.cs

@@ -31,8 +31,6 @@ namespace osu.Game.Rulesets.Catch.Tests
         [Resolved]
         private OsuConfigManager config { get; set; }
 
-        private CatcherTrailDisplay trailDisplay;
-
         private DroppedObjectContainer droppedObjectContainer;
 
         private TestCatcher catcher;
@@ -45,7 +43,6 @@ namespace osu.Game.Rulesets.Catch.Tests
                 CircleSize = 0,
             };
 
-            trailDisplay = new CatcherTrailDisplay();
             droppedObjectContainer = new DroppedObjectContainer();
 
             Child = new Container
@@ -54,8 +51,7 @@ namespace osu.Game.Rulesets.Catch.Tests
                 Children = new Drawable[]
                 {
                     droppedObjectContainer,
-                    catcher = new TestCatcher(trailDisplay, droppedObjectContainer, difficulty),
+                    catcher = new TestCatcher(droppedObjectContainer, difficulty),
-                    trailDisplay,
                 }
             };
         });
@@ -294,8 +290,8 @@ namespace osu.Game.Rulesets.Catch.Tests
         {
             public IEnumerable<CaughtObject> CaughtObjects => this.ChildrenOfType<CaughtObject>();
 
-            public TestCatcher(CatcherTrailDisplay trails, DroppedObjectContainer droppedObjectTarget, BeatmapDifficulty difficulty)
+            public TestCatcher(DroppedObjectContainer droppedObjectTarget, BeatmapDifficulty difficulty)
-                : base(trails, droppedObjectTarget, difficulty)
+                : base(droppedObjectTarget, difficulty)
             {
             }
         }

osu.Game.Rulesets.Catch.Tests/TestSceneCatcherArea.cs

@@ -121,13 +121,10 @@ namespace osu.Game.Rulesets.Catch.Tests
         {
             public TestCatcherArea(BeatmapDifficulty beatmapDifficulty)
             {
-                var trailDisplay = new CatcherTrailDisplay { Depth = -1 };
-                Add(trailDisplay);
-
                 var droppedObjectContainer = new DroppedObjectContainer();
                 Add(droppedObjectContainer);
 
-                Catcher = new Catcher(trailDisplay, droppedObjectContainer, beatmapDifficulty)
+                Catcher = new Catcher(droppedObjectContainer, beatmapDifficulty)
                 {
                     X = CatchPlayfield.CENTER_X
                 };

osu.Game.Rulesets.Catch.Tests/TestSceneHyperDashColouring.cs

@@ -118,19 +118,19 @@ namespace osu.Game.Rulesets.Catch.Tests
 
             AddStep("create hyper-dashing catcher", () =>
             {
-                trails = new CatcherTrailDisplay();
+                CatcherArea catcherArea;
                 Child = setupSkinHierarchy(new Container
                 {
                     Anchor = Anchor.Centre,
-                    Children = new Drawable[]
+                    Child = catcherArea = new CatcherArea
                     {
-                        catcher = new Catcher(trails, new DroppedObjectContainer())
+                        Catcher = catcher = new Catcher(new DroppedObjectContainer())
                         {
                             Scale = new Vector2(4)
-                        },
+                        }
-                        trails
                     }
                 }, skin);
+                trails = catcherArea.CatcherTrails;
             });
 
             AddStep("start hyper-dash", () =>

osu.Game.Rulesets.Catch/UI/CatchPlayfield.cs

@@ -44,14 +44,9 @@ namespace osu.Game.Rulesets.Catch.UI
         [BackgroundDependencyLoader]
         private void load()
         {
-            var trailDisplay = new CatcherTrailDisplay
-            {
-                Anchor = Anchor.BottomLeft,
-                Origin = Anchor.TopLeft
-            };
             var droppedObjectContainer = new DroppedObjectContainer();
 
-            Catcher = new Catcher(trailDisplay, droppedObjectContainer, difficulty)
+            Catcher = new Catcher(droppedObjectContainer, difficulty)
             {
                 X = CENTER_X
             };
@@ -69,7 +64,6 @@ namespace osu.Game.Rulesets.Catch.UI
                     Origin = Anchor.TopLeft,
                     Catcher = Catcher,
                 },
-                trailDisplay,
                 HitObjectContainer,
             });
 

osu.Game.Rulesets.Catch/UI/Catcher.cs

@@ -71,11 +71,6 @@ namespace osu.Game.Rulesets.Catch.UI
         /// </summary>
         private const float caught_fruit_scale_adjust = 0.5f;
 
-        /// <summary>
-        /// Contains trails and afterimages (also called "end glow" in code) of the catcher.
-        /// </summary>
-        private readonly CatcherTrailDisplay trails;
-
         /// <summary>
         /// Contains caught objects on the plate.
         /// </summary>
@@ -102,6 +97,8 @@ namespace osu.Game.Rulesets.Catch.UI
         /// </summary>
         public Direction VisualDirection { get; set; } = Direction.Right;
 
+        public Vector2 BodyScale => Scale * body.Scale;
+
         /// <summary>
         /// Whether the contents of the catcher plate should be visually flipped when the catcher direction is changed.
         /// </summary>
@@ -127,9 +124,8 @@ namespace osu.Game.Rulesets.Catch.UI
         private readonly DrawablePool<CaughtBanana> caughtBananaPool;
         private readonly DrawablePool<CaughtDroplet> caughtDropletPool;
 
-        public Catcher([NotNull] CatcherTrailDisplay trails, [NotNull] DroppedObjectContainer droppedObjectTarget, BeatmapDifficulty difficulty = null)
+        public Catcher([NotNull] DroppedObjectContainer droppedObjectTarget, BeatmapDifficulty difficulty = null)
         {
-            this.trails = trails;
             this.droppedObjectTarget = droppedObjectTarget;
 
             Origin = Anchor.TopCentre;
@@ -292,12 +288,9 @@ namespace osu.Game.Rulesets.Catch.UI
                 hyperDashTargetPosition = targetPosition;
 
                 if (!wasHyperDashing)
-                {
-                    trails.DisplayEndGlow(CurrentState, X, Scale * body.Scale);
                     runHyperDashStateTransition(true);
             }
         }
-        }
 
         /// <summary>
         /// Drop any fruit off the plate.
@@ -342,15 +335,6 @@ namespace osu.Game.Rulesets.Catch.UI
                 X = hyperDashTargetPosition;
                 SetHyperDashState();
             }
-
-            if (Dashing || HyperDashing)
-            {
-                double lastTrailTime = trails.LastDashTrail?.LifetimeStart ?? double.NegativeInfinity;
-                double generationInterval = HyperDashing ? 25 : 50;
-
-                if (Time.Current - lastTrailTime >= generationInterval)
-                    trails.DisplayDashTrail(CurrentState, X, Scale * body.Scale, HyperDashing);
-            }
         }
 
         private void placeCaughtObject(DrawablePalpableCatchHitObject drawableObject, Vector2 position)

osu.Game.Rulesets.Catch/UI/CatcherArea.cs

@@ -25,14 +25,12 @@ namespace osu.Game.Rulesets.Catch.UI
         public Catcher Catcher
         {
             get => catcher;
-            set
+            set => catcherContainer.Child = catcher = value;
-            {
+        }
-                if (catcher != null)
-                    Remove(catcher);
 
-                Add(catcher = value);
+        internal CatcherTrailDisplay CatcherTrails { get; }
-            }
+
-        }
+        private readonly Container<Catcher> catcherContainer;
 
         private readonly CatchComboDisplay comboDisplay;
 
@@ -45,13 +43,20 @@ namespace osu.Game.Rulesets.Catch.UI
         /// </summary>
         private int currentDirection;
 
+        // TODO: support replay rewind
+        private bool lastHyperDashState;
+
         /// <remarks>
         /// <see cref="Catcher"/> must be set before loading.
         /// </remarks>
         public CatcherArea()
         {
             Size = new Vector2(CatchPlayfield.WIDTH, Catcher.BASE_SIZE);
-            Child = comboDisplay = new CatchComboDisplay
+            Children = new Drawable[]
+            {
+                catcherContainer = new Container<Catcher> { RelativeSizeAxes = Axes.Both },
+                CatcherTrails = new CatcherTrailDisplay(),
+                comboDisplay = new CatchComboDisplay
                 {
                     RelativeSizeAxes = Axes.None,
                     AutoSizeAxes = Axes.Both,
@@ -59,6 +64,7 @@ namespace osu.Game.Rulesets.Catch.UI
                     Origin = Anchor.Centre,
                     Margin = new MarginPadding { Bottom = 350f },
                     X = CatchPlayfield.CENTER_X
+                }
             };
         }
 
@@ -102,6 +108,20 @@ namespace osu.Game.Rulesets.Catch.UI
             base.UpdateAfterChildren();
 
             comboDisplay.X = Catcher.X;
+
+            if (!lastHyperDashState && Catcher.HyperDashing && Time.Elapsed > 0)
+                CatcherTrails.DisplayEndGlow(Catcher.CurrentState, Catcher.X, Catcher.BodyScale);
+
+            if (Catcher.Dashing || Catcher.HyperDashing)
+            {
+                double lastTrailTime = CatcherTrails.LastDashTrail?.LifetimeStart ?? double.NegativeInfinity;
+                double generationInterval = Catcher.HyperDashing ? 25 : 50;
+
+                if (Time.Current - lastTrailTime >= generationInterval)
+                    CatcherTrails.DisplayDashTrail(Catcher.CurrentState, Catcher.X, Catcher.BodyScale, Catcher.HyperDashing);
+            }
+
+            lastHyperDashState = Catcher.HyperDashing;
         }
 
         public void SetCatcherPosition(float X)