Improve sb sprite end time guessing

osu.Game/Storyboards/CommandTimelineGroup.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 System;
 using osuTK;
 using osuTK.Graphics;
 using osu.Framework.Graphics;
@@ -46,32 +45,10 @@ namespace osu.Game.Storyboards
         }
 
         [JsonIgnore]
-        public double CommandsStartTime
+        public double CommandsStartTime => timelines.Min(static t => t.StartTime);
-        {
-            get
-            {
-                double min = double.MaxValue;
-
-                for (int i = 0; i < timelines.Length; i++)
-                    min = Math.Min(min, timelines[i].StartTime);
-
-                return min;
-            }
-        }
 
         [JsonIgnore]
-        public double CommandsEndTime
+        public double CommandsEndTime => timelines.Max(static t => t.EndTime);
-        {
-            get
-            {
-                double max = double.MinValue;
-
-                for (int i = 0; i < timelines.Length; i++)
-                    max = Math.Max(max, timelines[i].EndTime);
-
-                return max;
-            }
-        }
 
         [JsonIgnore]
         public double CommandsDuration => CommandsEndTime - CommandsStartTime;
@@ -83,19 +60,7 @@ namespace osu.Game.Storyboards
         public virtual double EndTime => CommandsEndTime;
 
         [JsonIgnore]
-        public bool HasCommands
+        public bool HasCommands => timelines.Any(static t => t.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)
         {

osu.Game/Storyboards/StoryboardSprite.cs

@@ -85,12 +85,56 @@ namespace osu.Game.Storyboards
         {
             get
             {
-                double latestEndTime = TimelineGroup.EndTime;
+                double latestEndTime = double.MaxValue;
+
+                // Ignore the whole setup if there are loops. In theory they can be handled here too, however the logic will be overly complex.
+                if (loops.Count == 0)
+                {
+                    // Here we are starting from maximum value and trying to minimise the end time on each step.
+                    // There are few solid guesses we can make using which sprite's end time can be minimised: alpha = 0, scale = 0, colour.a = 0.
+                    double[] deathTimes =
+                    {
+                        double.MaxValue, // alpha
+                        double.MaxValue, // colour alpha
+                        double.MaxValue, // scale
+                        double.MaxValue, // scale x
+                        double.MaxValue, // scale y
+                    };
+
+                    // The loops below are following the same pattern.
+                    // We could be using TimelineGroup.EndValue here, however it's possible to have multiple commands with 0 value in a row
+                    // so we are saving the earliest of them.
+                    foreach (var alphaCommand in TimelineGroup.Alpha.Commands)
+                    {
+                        deathTimes[0] = alphaCommand.EndValue == 0
+                            ? Math.Min(alphaCommand.EndTime, deathTimes[0]) // commands are ordered by the start time, however end time may vary. Save the earliest.
+                            : double.MaxValue; // If value isn't 0 (sprite becomes visible again), revert the saved state.
+                    }
+
+                    foreach (var colourCommand in TimelineGroup.Colour.Commands)
+                        deathTimes[1] = colourCommand.EndValue.A == 0 ? Math.Min(colourCommand.EndTime, deathTimes[1]) : double.MaxValue;
+
+                    foreach (var scaleCommand in TimelineGroup.Scale.Commands)
+                        deathTimes[2] = scaleCommand.EndValue == 0 ? Math.Min(scaleCommand.EndTime, deathTimes[2]) : double.MaxValue;
+
+                    foreach (var scaleCommand in TimelineGroup.VectorScale.Commands)
+                    {
+                        deathTimes[3] = scaleCommand.EndValue.X == 0 ? Math.Min(scaleCommand.EndTime, deathTimes[3]) : double.MaxValue;
+                        deathTimes[4] = scaleCommand.EndValue.Y == 0 ? Math.Min(scaleCommand.EndTime, deathTimes[4]) : double.MaxValue;
+                    }
+
+                    // Take the minimum time of all the potential "death" reasons.
+                    latestEndTime = deathTimes.Min();
+                }
+
+                // If the logic above fails to find anything or discarded by the fact that there are loops present, latestEndTime will be double.MaxValue
+                // and thus conservativeEndTime will be used.
+                double conservativeEndTime = TimelineGroup.EndTime;
 
                 foreach (var l in loops)
-                    latestEndTime = Math.Max(latestEndTime, l.StartTime + l.CommandsDuration * l.TotalIterations);
+                    conservativeEndTime = Math.Max(conservativeEndTime, l.StartTime + l.CommandsDuration * l.TotalIterations);
 
-                return latestEndTime;
+                return Math.Min(latestEndTime, conservativeEndTime);
             }
         }