From 8d6987c8703d27b4459fb3f30f586a1b1b9ae8a9 Mon Sep 17 00:00:00 2001
From: smoogipoo <smoogipoo@smgi.me>
Date: Wed, 18 Dec 2019 23:59:48 +0900
Subject: [PATCH] Refactor storyboard timeline to reduce GC / fix crashes

---
 osu.Game/Storyboards/CommandTimeline.cs      | 29 +++++----
 osu.Game/Storyboards/CommandTimelineGroup.cs | 65 +++++++++++++++-----
 2 files changed, 69 insertions(+), 25 deletions(-)

diff --git a/osu.Game/Storyboards/CommandTimeline.cs b/osu.Game/Storyboards/CommandTimeline.cs
index bcf642b4ea..c71806352d 100644
--- a/osu.Game/Storyboards/CommandTimeline.cs
+++ b/osu.Game/Storyboards/CommandTimeline.cs
@@ -1,7 +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.
 
-using osu.Framework.Caching;
 using osu.Framework.Graphics;
 using System;
 using System.Collections.Generic;
@@ -12,27 +11,35 @@ namespace osu.Game.Storyboards
     public class CommandTimeline<T> : ICommandTimeline
     {
         private readonly List<TypedCommand> commands = new List<TypedCommand>();
+
         public IEnumerable<TypedCommand> Commands => commands.OrderBy(c => c.StartTime);
+
         public bool HasCommands => commands.Count > 0;
 
-        private readonly Cached<double> startTimeBacking = new Cached<double>();
-        public double StartTime => startTimeBacking.IsValid ? startTimeBacking : startTimeBacking.Value = HasCommands ? commands.Min(c => c.StartTime) : double.MinValue;
+        public double StartTime { get; private set; } = double.MaxValue;
+        public double EndTime { get; private set; } = double.MinValue;
 
-        private readonly Cached<double> endTimeBacking = new Cached<double>();
-        public double EndTime => endTimeBacking.IsValid ? endTimeBacking : endTimeBacking.Value = HasCommands ? commands.Max(c => c.EndTime) : double.MaxValue;
-
-        public T StartValue => HasCommands ? commands.OrderBy(c => c.StartTime).First().StartValue : default;
-        public T EndValue => HasCommands ? commands.OrderByDescending(c => c.EndTime).First().EndValue : default;
+        public T StartValue { get; private set; }
+        public T EndValue { get; private set; }
 
         public void Add(Easing easing, double startTime, double endTime, T startValue, T endValue)
         {
             if (endTime < startTime)
                 return;
 
-            commands.Add(new TypedCommand { Easing = easing, StartTime = startTime, EndTime = endTime, StartValue = startValue, EndValue = endValue, });
+            commands.Add(new TypedCommand { Easing = easing, StartTime = startTime, EndTime = endTime, StartValue = startValue, EndValue = endValue });
 
-            startTimeBacking.Invalidate();
-            endTimeBacking.Invalidate();
+            if (startTime < StartTime)
+            {
+                StartValue = startValue;
+                StartTime = startTime;
+            }
+
+            if (endTime > EndTime)
+            {
+                EndValue = endValue;
+                EndTime = endTime;
+            }
         }
 
         public override string ToString()
diff --git a/osu.Game/Storyboards/CommandTimelineGroup.cs b/osu.Game/Storyboards/CommandTimelineGroup.cs
index 7b6e667d4f..6ce3b617e9 100644
--- a/osu.Game/Storyboards/CommandTimelineGroup.cs
+++ b/osu.Game/Storyboards/CommandTimelineGroup.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 osuTK;
 using osuTK.Graphics;
 using osu.Framework.Graphics;
@@ -25,28 +26,52 @@ namespace osu.Game.Storyboards
         public CommandTimeline<bool> FlipH = new CommandTimeline<bool>();
         public CommandTimeline<bool> FlipV = new CommandTimeline<bool>();
 
+        private readonly ICommandTimeline[] timelines;
+
+        public CommandTimelineGroup()
+        {
+            timelines = new ICommandTimeline[]
+            {
+                X,
+                Y,
+                Scale,
+                VectorScale,
+                Rotation,
+                Colour,
+                Alpha,
+                BlendingParameters,
+                FlipH,
+                FlipV
+            };
+        }
+
         [JsonIgnore]
-        public IEnumerable<ICommandTimeline> Timelines
+        public double CommandsStartTime
         {
             get
             {
-                yield return X;
-                yield return Y;
-                yield return Scale;
-                yield return Rotation;
-                yield return Colour;
-                yield return Alpha;
-                yield return BlendingParameters;
-                yield return FlipH;
-                yield return FlipV;
+                double min = double.MaxValue;
+
+                for (int i = 0; i < timelines.Length; i++)
+                    min = Math.Min(min, timelines[i].StartTime);
+
+                return min;
             }
         }
 
         [JsonIgnore]
-        public double CommandsStartTime => Timelines.Where(t => t.HasCommands).Min(t => t.StartTime);
+        public double CommandsEndTime
+        {
+            get
+            {
+                double max = double.MinValue;
 
-        [JsonIgnore]
-        public double CommandsEndTime => Timelines.Where(t => t.HasCommands).Max(t => t.EndTime);
+                for (int i = 0; i < timelines.Length; i++)
+                    max = Math.Max(max, timelines[i].EndTime);
+
+                return max;
+            }
+        }
 
         [JsonIgnore]
         public double CommandsDuration => CommandsEndTime - CommandsStartTime;
@@ -61,7 +86,19 @@ namespace osu.Game.Storyboards
         public double Duration => EndTime - StartTime;
 
         [JsonIgnore]
-        public bool HasCommands => Timelines.Any(t => t.HasCommands);
+        public bool HasCommands
+        {
+            get
+            {
+                for (int i = 0; i < timelines.Length; i++)
+                {
+                    if (timelines[i].HasCommands)
+                        return true;
+                }
+
+                return false;
+            }
+        }
 
         public virtual IEnumerable<CommandTimeline<T>.TypedCommand> GetCommands<T>(CommandTimelineSelector<T> timelineSelector, double offset = 0)
         {