Add leaderboard display to realtime player

osu.Game/Screens/Multi/RealtimeMultiplayer/RealtimePlayer.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Diagnostics;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using osu.Framework.Allocation;
@@ -12,7 +13,9 @@
 using osu.Game.Online.RealtimeMultiplayer;
 using osu.Game.Scoring;
 using osu.Game.Screens.Multi.Play;
+using osu.Game.Screens.Play.HUD;
 using osu.Game.Screens.Ranking;
+using osuTK;
 
 namespace osu.Game.Screens.Multi.RealtimeMultiplayer
 {
@@ -30,6 +33,8 @@ public class RealtimePlayer : TimeshiftPlayer
         private readonly TaskCompletionSource<bool> resultsReady = new TaskCompletionSource<bool>();
         private readonly ManualResetEventSlim startedEvent = new ManualResetEventSlim();
 
+        private MultiplayerGameplayLeaderboard leaderboard;
+
         public RealtimePlayer(PlaylistItem playlistItem)
             : base(playlistItem, false)
         {
@@ -55,6 +60,24 @@ private void load()
                     this.Exit();
                 });
             }
+
+            Debug.Assert(client.Room != null);
+
+            int[] userIds = client.Room.Users.Where(u => u.State >= MultiplayerUserState.WaitingForLoad).Select(u => u.UserID).ToArray();
+
+            // todo: this should be implemented via a custom HUD implementation, and correctly masked to the main content area.
+            LoadComponentAsync(leaderboard = new MultiplayerGameplayLeaderboard(ScoreProcessor, userIds), HUDOverlay.Add);
+        }
+
+        protected override void Update()
+        {
+            base.Update();
+
+            const float padding = 44; // enough margin to avoid the hit error display.
+
+            leaderboard.Position = new Vector2(
+                padding,
+                padding + HUDOverlay.TopScoringElementsHeight);
         }
 
         private void onMatchStarted() => startedEvent.Set();

osu.Game/Screens/Play/HUDOverlay.cs

@@ -28,6 +28,11 @@ public class HUDOverlay : Container, IKeyBindingHandler<GlobalAction>
 
         public const Easing FADE_EASING = Easing.Out;
 
+        /// <summary>
+        /// The total height of all the top of screen scoring elements.
+        /// </summary>
+        public float TopScoringElementsHeight { get; private set; }
+
         public readonly KeyCounterDisplay KeyCounter;
         public readonly SkinnableComboCounter ComboCounter;
         public readonly SkinnableScoreCounter ScoreCounter;
@@ -209,7 +214,7 @@ protected override void Update()
             // HACK: for now align with the accuracy counter.
             // this is done for the sake of hacky legacy skins which extend the health bar to take up the full screen area.
             // it only works with the default skin due to padding offsetting it *just enough* to coexist.
-            topRightElements.Y = ToLocalSpace(AccuracyCounter.Drawable.ScreenSpaceDrawQuad.BottomRight).Y;
+            topRightElements.Y = TopScoringElementsHeight = ToLocalSpace(AccuracyCounter.Drawable.ScreenSpaceDrawQuad.BottomRight).Y;
 
             bottomRightElements.Y = -Progress.Height;
         }