From a9286fee07fc2c814062586a49ee116fb719334b Mon Sep 17 00:00:00 2001
From: smoogipoo <smoogipoo@smgi.me>
Date: Tue, 16 Jul 2019 18:19:13 +0900
Subject: [PATCH] Recycle slider paths when the parenting slider dies

---
 .../Objects/Drawables/DrawableSlider.cs       |  6 ++++++
 .../Objects/Drawables/Pieces/SliderBody.cs    | 19 ++++++++++++++++++-
 .../Objects/Drawables/DrawableHitObject.cs    |  8 ++++----
 osu.Game/Rulesets/UI/HitObjectContainer.cs    | 10 ++++++++--
 4 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableSlider.cs b/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableSlider.cs
index 05cb42d853..4d67c9ae34 100644
--- a/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableSlider.cs
+++ b/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableSlider.cs
@@ -156,6 +156,12 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables
             }
         }
 
+        public override void OnKilled()
+        {
+            base.OnKilled();
+            Body.RecyclePath();
+        }
+
         protected override void SkinChanged(ISkinSource skin, bool allowFallback)
         {
             base.SkinChanged(skin, allowFallback);
diff --git a/osu.Game.Rulesets.Osu/Objects/Drawables/Pieces/SliderBody.cs b/osu.Game.Rulesets.Osu/Objects/Drawables/Pieces/SliderBody.cs
index 33b3667c4f..97c7c9cec5 100644
--- a/osu.Game.Rulesets.Osu/Objects/Drawables/Pieces/SliderBody.cs
+++ b/osu.Game.Rulesets.Osu/Objects/Drawables/Pieces/SliderBody.cs
@@ -13,7 +13,8 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables.Pieces
     {
         public const float DEFAULT_BORDER_SIZE = 1;
 
-        private readonly SliderPath path;
+        private SliderPath path;
+
         protected Path Path => path;
 
         public float PathRadius
@@ -77,6 +78,22 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables.Pieces
             InternalChild = path = new SliderPath();
         }
 
+        /// <summary>
+        /// Initialises a new <see cref="SliderPath"/>, releasing all resources retained by the old one.
+        /// </summary>
+        public void RecyclePath()
+        {
+            InternalChild = path = new SliderPath
+            {
+                Position = path.Position,
+                PathRadius = path.PathRadius,
+                AccentColour = path.AccentColour,
+                BorderColour = path.BorderColour,
+                BorderSize = path.BorderSize,
+                Vertices = path.Vertices
+            };
+        }
+
         public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => path.ReceivePositionalInputAt(screenSpacePos);
 
         /// <summary>
diff --git a/osu.Game/Rulesets/Objects/Drawables/DrawableHitObject.cs b/osu.Game/Rulesets/Objects/Drawables/DrawableHitObject.cs
index 76233eabf2..e61fac679e 100644
--- a/osu.Game/Rulesets/Objects/Drawables/DrawableHitObject.cs
+++ b/osu.Game/Rulesets/Objects/Drawables/DrawableHitObject.cs
@@ -7,7 +7,6 @@ using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Extensions.TypeExtensions;
-using osu.Framework.Graphics;
 using osu.Framework.Graphics.Primitives;
 using osu.Game.Audio;
 using osu.Game.Graphics;
@@ -202,12 +201,13 @@ namespace osu.Game.Rulesets.Objects.Drawables
         protected virtual double InitialLifetimeOffset => 10000;
 
         /// <summary>
-        /// Will called at least once after the <see cref="Drawable.LifetimeEnd"/> of this <see cref="DrawableHitObject"/> has been passed.
+        /// Will be called at least once after this <see cref="DrawableHitObject"/> has become not alive.
         /// </summary>
-        internal void OnLifetimeEnd()
+        public virtual void OnKilled()
         {
             foreach (var nested in NestedHitObjects)
-                nested.OnLifetimeEnd();
+                nested.OnKilled();
+
             UpdateResult(false);
         }
 
diff --git a/osu.Game/Rulesets/UI/HitObjectContainer.cs b/osu.Game/Rulesets/UI/HitObjectContainer.cs
index 2f3a384e95..aa942e70df 100644
--- a/osu.Game/Rulesets/UI/HitObjectContainer.cs
+++ b/osu.Game/Rulesets/UI/HitObjectContainer.cs
@@ -34,8 +34,14 @@ namespace osu.Game.Rulesets.UI
 
         protected override void OnChildLifetimeBoundaryCrossed(LifetimeBoundaryCrossedEvent e)
         {
-            if (e.Kind == LifetimeBoundaryKind.End && e.Direction == LifetimeBoundaryCrossingDirection.Forward && e.Child is DrawableHitObject hitObject)
-                hitObject.OnLifetimeEnd();
+            if (!(e.Child is DrawableHitObject hitObject))
+                return;
+
+            if (e.Kind == LifetimeBoundaryKind.End && e.Direction == LifetimeBoundaryCrossingDirection.Forward
+                || e.Kind == LifetimeBoundaryKind.Start && e.Direction == LifetimeBoundaryCrossingDirection.Backward)
+            {
+                hitObject.OnKilled();
+            }
         }
     }
 }