Add second definition of EndTime for storyboard elements to account for loops in lifetime

osu.Game.Tests/Beatmaps/Formats/LegacyStoryboardDecoderTest.cs

@@ -110,7 +110,9 @@ namespace osu.Game.Tests.Beatmaps.Formats
 
                 Assert.AreEqual(2000, background.Elements[0].StartTime);
                 Assert.AreEqual(2000, (background.Elements[0] as StoryboardAnimation)?.EarliestTransformTime);
-                Assert.AreEqual(12000, (background.Elements[0] as StoryboardAnimation)?.GetEndTime());
+
+                Assert.AreEqual(3000, (background.Elements[0] as StoryboardAnimation)?.GetEndTime());
+                Assert.AreEqual(12000, (background.Elements[0] as StoryboardAnimation)?.EndTimeForDisplay);
             }
         }
 

osu.Game.Tests/Visual/Background/TestSceneBackgroundScreenDefault.cs

@@ -311,6 +311,7 @@ namespace osu.Game.Tests.Visual.Background
                 public bool IsDrawable => true;
                 public double StartTime => double.MinValue;
                 public double EndTime => double.MaxValue;
+                public double EndTimeForDisplay => double.MaxValue;
 
                 public Drawable CreateDrawable() => new DrawableTestStoryboardElement();
             }

osu.Game/Storyboards/IStoryboardElementWithDuration.cs

@@ -12,9 +12,17 @@ namespace osu.Game.Storyboards
     {
         /// <summary>
         /// The time at which the <see cref="IStoryboardElement"/> ends.
+        /// This is consumed to extend the length of a storyboard to ensure all visuals are played to completion.
         /// </summary>
         double EndTime { get; }
 
+        /// <summary>
+        /// The time this element displays until.
+        /// This is used for lifetime purposes, and includes long playing animations which don't necessarily extend
+        /// a storyboard's play time.
+        /// </summary>
+        double EndTimeForDisplay { get; }
+
         /// <summary>
         /// The duration of the StoryboardElement.
         /// </summary>

osu.Game/Storyboards/StoryboardSprite.cs

@@ -81,6 +81,19 @@ namespace osu.Game.Storyboards
             }
         }
 
+        public double EndTimeForDisplay
+        {
+            get
+            {
+                double latestEndTime = TimelineGroup.EndTime;
+
+                foreach (var l in loops)
+                    latestEndTime = Math.Max(latestEndTime, l.StartTime + l.CommandsDuration * l.TotalIterations);
+
+                return latestEndTime;
+            }
+        }
+
         public bool HasCommands => TimelineGroup.HasCommands || loops.Any(l => l.HasCommands);
 
         private delegate void DrawablePropertyInitializer<in T>(Drawable drawable, T value);