Reduce number of redundant control points displayed on summary timeline

osu.Game/Screens/Edit/Components/Timelines/Summary/Parts/ControlPointPart.cs

@@ -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.Specialized;
 using System.Linq;
 using osu.Framework.Bindables;
@@ -31,15 +32,37 @@ protected override void LoadBeatmap(EditorBeatmap beatmap)
 
                     case NotifyCollectionChangedAction.Add:
                         foreach (var group in args.NewItems.OfType<ControlPointGroup>())
+                        {
+                            // as an optimisation, don't add a visualisation if there are already groups with the same types in close proximity.
+                            // for newly added control points (ie. lazer editor first where group is added empty) we always skip for simplicity.
+                            // that is fine, because cases where this is causing a performance issue are mostly where external tools were used to create an insane number of points.
+                            if (Children.Any(g => Math.Abs(g.Group.Time - group.Time) < 1000 && g.IsRedundant(group)))
+                                continue;
+
                             Add(new GroupVisualisation(group));
+                        }
+
                         break;
 
                     case NotifyCollectionChangedAction.Remove:
                         foreach (var group in args.OldItems.OfType<ControlPointGroup>())
                         {
                             var matching = Children.SingleOrDefault(gv => gv.Group == group);
 
-                            matching?.Expire();
+                            if (matching != null)
+                                matching.Expire();
+                            else
+                            {
+                                // due to the add optimisation above, if a point is deleted which wasn't being displayed we need to recreate all points
+                                // to guarantee an accurate representation.
+                                //
+                                // note that the case where control point (type) is added or removed from a non-displayed group is not handled correctly.
+                                // this is an edge case which shouldn't affect the user too badly. we may flatted control point groups in the future
+                                // which would allow this to be handled better.
+                                Clear();
+                                foreach (var g in controlPointGroups)
+                                    Add(new GroupVisualisation(g));
+                            }
                         }
 
                         break;

osu.Game/Screens/Edit/Components/Timelines/Summary/Parts/ControlPointVisualisation.cs

@@ -9,7 +9,7 @@
 
 namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
 {
-    public class ControlPointVisualisation : PointVisualisation
+    public class ControlPointVisualisation : PointVisualisation, IControlPointVisualisationRedundant
     {
         protected readonly ControlPoint Point;
 
@@ -26,5 +26,7 @@ private void load(OsuColour colours)
         {
             Colour = Point.GetRepresentingColour(colours);
         }
+
+        public bool IsRedundant(ControlPoint other) => other.GetType() == Point.GetType();
     }
 }

osu.Game/Screens/Edit/Components/Timelines/Summary/Parts/EffectPointVisualisation.cs

@@ -13,7 +13,7 @@
 
 namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
 {
-    public class EffectPointVisualisation : CompositeDrawable
+    public class EffectPointVisualisation : CompositeDrawable, IControlPointVisualisationRedundant
     {
         private readonly EffectControlPoint effect;
         private Bindable<bool> kiai;
@@ -68,5 +68,8 @@ private void load()
                 }
             }, true);
         }
+
+        // kiai sections display duration, so are required to be visualised.
+        public bool IsRedundant(ControlPoint other) => (other as EffectControlPoint)?.KiaiMode == effect.KiaiMode;
     }
 }

osu.Game/Screens/Edit/Components/Timelines/Summary/Parts/GroupVisualisation.cs

@@ -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.Linq;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -23,12 +24,8 @@ public GroupVisualisation(ControlPointGroup group)
 
             Group = group;
             X = (float)group.Time;
-        }
-
-        protected override void LoadComplete()
-        {
-            base.LoadComplete();
 
+            // Run in constructor so IsRedundant calls can work correctly.
             controlPoints.BindTo(Group.ControlPoints);
             controlPoints.BindCollectionChanged((_, __) =>
             {
@@ -60,5 +57,13 @@ protected override void LoadComplete()
                 }
             }, true);
         }
+
+        /// <summary>
+        /// For display purposes, check whether the proposed group is made redundant by this visualisation group.
+        /// </summary>
+        /// <param name="other"></param>
+        /// <returns></returns>
+        public bool IsRedundant(ControlPointGroup other) =>
+            other.ControlPoints.Any(c => InternalChildren.OfType<IControlPointVisualisationRedundant>().Any(c2 => c2.IsRedundant(c)));
     }
 }

osu.Game/Screens/Edit/Components/Timelines/Summary/Parts/IControlPointVisualisationRedundant.cs

@@ -0,0 +1,12 @@
+// 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.Game.Beatmaps.ControlPoints;
+
+namespace osu.Game.Screens.Edit.Components.Timelines.Summary.Parts
+{
+    public interface IControlPointVisualisationRedundant
+    {
+        bool IsRedundant(ControlPoint other);
+    }
+}