From 8d925c8a8a5f06c33bddcf28b543a784a159b71a Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Wed, 17 May 2023 17:19:07 +0900
Subject: [PATCH] Move combo information updating to an interface level helper
 method

---
 osu.Game/Beatmaps/BeatmapProcessor.cs         | 27 +++----------------
 .../Objects/Types/IHasComboInformation.cs     | 23 ++++++++++++++--
 2 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/osu.Game/Beatmaps/BeatmapProcessor.cs b/osu.Game/Beatmaps/BeatmapProcessor.cs
index 8f3d0b7445..fb5313469f 100644
--- a/osu.Game/Beatmaps/BeatmapProcessor.cs
+++ b/osu.Game/Beatmaps/BeatmapProcessor.cs
@@ -1,8 +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.
 
-#nullable disable
-
 using System.Linq;
 using osu.Game.Rulesets.Objects.Types;
 
@@ -22,34 +20,17 @@ namespace osu.Game.Beatmaps
 
         public virtual void PreProcess()
         {
-            IHasComboInformation lastObj = null;
-
-            bool isFirst = true;
+            IHasComboInformation? lastObj = null;
 
             foreach (var obj in Beatmap.HitObjects.OfType<IHasComboInformation>())
             {
-                if (isFirst)
+                if (lastObj == null)
                 {
-                    obj.NewCombo = true;
-
                     // first hitobject should always be marked as a new combo for sanity.
-                    isFirst = false;
-                }
-
-                obj.ComboIndex = lastObj?.ComboIndex ?? 0;
-                obj.ComboIndexWithOffsets = lastObj?.ComboIndexWithOffsets ?? 0;
-                obj.IndexInCurrentCombo = (lastObj?.IndexInCurrentCombo + 1) ?? 0;
-
-                if (obj.NewCombo)
-                {
-                    obj.IndexInCurrentCombo = 0;
-                    obj.ComboIndex++;
-                    obj.ComboIndexWithOffsets += obj.ComboOffset + 1;
-
-                    if (lastObj != null)
-                        lastObj.LastInCombo = true;
+                    obj.NewCombo = true;
                 }
 
+                obj.UpdateComboInformation(lastObj);
                 lastObj = obj;
             }
         }
diff --git a/osu.Game/Rulesets/Objects/Types/IHasComboInformation.cs b/osu.Game/Rulesets/Objects/Types/IHasComboInformation.cs
index b45ea989f3..d34e71021f 100644
--- a/osu.Game/Rulesets/Objects/Types/IHasComboInformation.cs
+++ b/osu.Game/Rulesets/Objects/Types/IHasComboInformation.cs
@@ -1,8 +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.
 
-#nullable disable
-
 using osu.Framework.Bindables;
 using osu.Game.Skinning;
 using osuTK.Graphics;
@@ -65,5 +63,26 @@ namespace osu.Game.Rulesets.Objects.Types
         {
             return skin.GetConfig<SkinComboColourLookup, Color4>(new SkinComboColourLookup(comboIndex, combo))?.Value ?? Color4.White;
         }
+
+        /// <summary>
+        /// Given the previous object in the beatmap, update relevant combo information.
+        /// </summary>
+        /// <param name="lastObj">The previous hitobject, or null if this is the first object in the beatmap.</param>
+        void UpdateComboInformation(IHasComboInformation? lastObj)
+        {
+            ComboIndex = lastObj?.ComboIndex ?? 0;
+            ComboIndexWithOffsets = lastObj?.ComboIndexWithOffsets ?? 0;
+            IndexInCurrentCombo = (lastObj?.IndexInCurrentCombo + 1) ?? 0;
+
+            if (NewCombo || lastObj == null)
+            {
+                IndexInCurrentCombo = 0;
+                ComboIndex++;
+                ComboIndexWithOffsets += ComboOffset + 1;
+
+                if (lastObj != null)
+                    lastObj.LastInCombo = true;
+            }
+        }
     }
 }