SongSelectV2: Fix incorrect conditional being used for "split out" check

🤦

Have inlined the v1 usage so we don't accidentally do this again.

osu.Game/Screens/Select/BeatmapCarousel.cs

@@ -28,6 +28,7 @@ using osu.Game.Extensions;
 using osu.Game.Graphics.Containers;
 using osu.Game.Input.Bindings;
 using osu.Game.Screens.Select.Carousel;
+using osu.Game.Screens.Select.Filter;
 using osuTK;
 using osuTK.Input;
 
@@ -123,7 +124,7 @@ namespace osu.Game.Screens.Select
 
         private void loadNewRoot()
         {
-            beatmapsSplitOut = activeCriteria.SplitOutDifficulties;
+            beatmapsSplitOut = activeCriteria.Sort == SortMode.Difficulty;
 
             // Ensure no changes are made to the list while we are initialising items.
             // We'll catch up on changes via subscriptions anyway.
@@ -656,7 +657,7 @@ namespace osu.Game.Screens.Select
             {
                 PendingFilter = null;
 
-                if (activeCriteria.SplitOutDifficulties != beatmapsSplitOut)
+                if ((activeCriteria.Sort == SortMode.Difficulty) != beatmapsSplitOut)
                 {
                     loadNewRoot();
                     return;

osu.Game/Screens/Select/FilterCriteria.cs

@@ -20,11 +20,6 @@ namespace osu.Game.Screens.Select
         public GroupMode Group;
         public SortMode Sort;
 
-        /// <summary>
-        /// Whether the display of beatmap sets should be split apart per-difficulty for the current criteria.
-        /// </summary>
-        public bool SplitOutDifficulties => Sort == SortMode.Difficulty;
-
         public BeatmapSetInfo? SelectedBeatmapSet;
 
         public OptionalRange<double> StarDifficulty;

osu.Game/Screens/SelectV2/BeatmapCarousel.cs

@@ -471,16 +471,9 @@ namespace osu.Game.Screens.SelectV2
 
         private ScheduledDelegate? loadingDebounce;
 
-        /// <summary>
-        /// We need to track this state locally since `FilterCriteria` is passed by reference and not accurate.
-        /// It should really be a struct.
-        /// </summary>
-        private bool splitOutDifficulties;
-
         public void Filter(FilterCriteria criteria)
         {
-            bool resetDisplay = criteria.SplitOutDifficulties != splitOutDifficulties;
-            splitOutDifficulties = criteria.SplitOutDifficulties;
+            bool resetDisplay = grouping.BeatmapSetsGroupedTogether != BeatmapCarouselFilterGrouping.ShouldGroupBeatmapsTogether(criteria);
 
             Criteria = criteria;
 

osu.Game/Screens/SelectV2/BeatmapCarouselFilterGrouping.cs

@@ -48,7 +48,7 @@ namespace osu.Game.Screens.SelectV2
                 var criteria = getCriteria();
                 var newItems = new List<CarouselItem>();
 
-                BeatmapSetsGroupedTogether = criteria.Sort != SortMode.Difficulty && criteria.Group != GroupMode.Difficulty;
+                BeatmapSetsGroupedTogether = ShouldGroupBeatmapsTogether(criteria);
 
                 var groups = getGroups((List<CarouselItem>)items, criteria);
 
@@ -122,6 +122,11 @@ namespace osu.Game.Screens.SelectV2
             }, cancellationToken).ConfigureAwait(false);
         }
 
+        public static bool ShouldGroupBeatmapsTogether(FilterCriteria criteria)
+        {
+            return criteria.Sort != SortMode.Difficulty && criteria.Group != GroupMode.Difficulty;
+        }
+
         private List<GroupMapping> getGroups(List<CarouselItem> items, FilterCriteria criteria)
         {
             switch (criteria.Group)