From e1b2c63e0941a08606f95bb08d28712c73576582 Mon Sep 17 00:00:00 2001
From: ekrctb <ekrctb@gmail.com>
Date: Wed, 23 Jun 2021 14:08:24 +0900
Subject: [PATCH 1/2] Add `IApplicableToBeatmapProcessor` mod interface

---
 osu.Game/Beatmaps/WorkingBeatmap.cs            |  3 +++
 .../Mods/IApplicableToBeatmapProcessor.cs      | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 osu.Game/Rulesets/Mods/IApplicableToBeatmapProcessor.cs

diff --git a/osu.Game/Beatmaps/WorkingBeatmap.cs b/osu.Game/Beatmaps/WorkingBeatmap.cs
index 712a3dd33a..662d24cc83 100644
--- a/osu.Game/Beatmaps/WorkingBeatmap.cs
+++ b/osu.Game/Beatmaps/WorkingBeatmap.cs
@@ -133,6 +133,9 @@ namespace osu.Game.Beatmaps
 
                 IBeatmapProcessor processor = rulesetInstance.CreateBeatmapProcessor(converted);
 
+                foreach (var mod in mods.OfType<IApplicableToBeatmapProcessor>())
+                    mod.ApplyToBeatmapProcessor(processor);
+
                 processor?.PreProcess();
 
                 // Compute default values for hitobjects, including creating nested hitobjects in-case they're needed
diff --git a/osu.Game/Rulesets/Mods/IApplicableToBeatmapProcessor.cs b/osu.Game/Rulesets/Mods/IApplicableToBeatmapProcessor.cs
new file mode 100644
index 0000000000..e23a5d8d99
--- /dev/null
+++ b/osu.Game/Rulesets/Mods/IApplicableToBeatmapProcessor.cs
@@ -0,0 +1,18 @@
+// 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 osu.Game.Beatmaps;
+
+namespace osu.Game.Rulesets.Mods
+{
+    /// <summary>
+    /// Interface for a <see cref="Mod"/> that applies changes to a <see cref="BeatmapProcessor"/>.
+    /// </summary>
+    public interface IApplicableToBeatmapProcessor : IApplicableMod
+    {
+        /// <summary>
+        /// Applies this <see cref="Mod"/> to a <see cref="BeatmapProcessor"/>.
+        /// </summary>
+        void ApplyToBeatmapProcessor(IBeatmapProcessor beatmapProcessor);
+    }
+}

From a0fd7f72ac8968bfa6d7a430ab571bdf3e558582 Mon Sep 17 00:00:00 2001
From: ekrctb <ekrctb@gmail.com>
Date: Wed, 23 Jun 2021 14:11:25 +0900
Subject: [PATCH 2/2] Use IApplicableToBeatmapProcessor in CatchModHardRock

---
 osu.Game.Rulesets.Catch/Beatmaps/CatchBeatmapProcessor.cs | 8 ++++----
 osu.Game.Rulesets.Catch/Mods/CatchModHardRock.cs          | 8 ++++++--
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/osu.Game.Rulesets.Catch/Beatmaps/CatchBeatmapProcessor.cs b/osu.Game.Rulesets.Catch/Beatmaps/CatchBeatmapProcessor.cs
index fac5d03833..3a5322ce82 100644
--- a/osu.Game.Rulesets.Catch/Beatmaps/CatchBeatmapProcessor.cs
+++ b/osu.Game.Rulesets.Catch/Beatmaps/CatchBeatmapProcessor.cs
@@ -8,7 +8,6 @@ using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Catch.MathUtils;
 using osu.Game.Rulesets.Catch.Objects;
 using osu.Game.Rulesets.Catch.UI;
-using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Objects.Types;
 
 namespace osu.Game.Rulesets.Catch.Beatmaps
@@ -17,6 +16,8 @@ namespace osu.Game.Rulesets.Catch.Beatmaps
     {
         public const int RNG_SEED = 1337;
 
+        public bool HardRockOffsets { get; set; }
+
         public CatchBeatmapProcessor(IBeatmap beatmap)
             : base(beatmap)
         {
@@ -43,11 +44,10 @@ namespace osu.Game.Rulesets.Catch.Beatmaps
             }
         }
 
-        public static void ApplyPositionOffsets(IBeatmap beatmap, params Mod[] mods)
+        public void ApplyPositionOffsets(IBeatmap beatmap)
         {
             var rng = new FastRandom(RNG_SEED);
 
-            bool shouldApplyHardRockOffset = mods.Any(m => m is ModHardRock);
             float? lastPosition = null;
             double lastStartTime = 0;
 
@@ -58,7 +58,7 @@ namespace osu.Game.Rulesets.Catch.Beatmaps
                 switch (obj)
                 {
                     case Fruit fruit:
-                        if (shouldApplyHardRockOffset)
+                        if (HardRockOffsets)
                             applyHardRockOffset(fruit, ref lastPosition, ref lastStartTime, rng);
                         break;
 
diff --git a/osu.Game.Rulesets.Catch/Mods/CatchModHardRock.cs b/osu.Game.Rulesets.Catch/Mods/CatchModHardRock.cs
index 0dde6aa06e..68b6ce96a3 100644
--- a/osu.Game.Rulesets.Catch/Mods/CatchModHardRock.cs
+++ b/osu.Game.Rulesets.Catch/Mods/CatchModHardRock.cs
@@ -7,10 +7,14 @@ using osu.Game.Rulesets.Catch.Beatmaps;
 
 namespace osu.Game.Rulesets.Catch.Mods
 {
-    public class CatchModHardRock : ModHardRock, IApplicableToBeatmap
+    public class CatchModHardRock : ModHardRock, IApplicableToBeatmapProcessor
     {
         public override double ScoreMultiplier => 1.12;
 
-        public void ApplyToBeatmap(IBeatmap beatmap) => CatchBeatmapProcessor.ApplyPositionOffsets(beatmap, this);
+        public void ApplyToBeatmapProcessor(IBeatmapProcessor beatmapProcessor)
+        {
+            var catchProcessor = (CatchBeatmapProcessor)beatmapProcessor;
+            catchProcessor.HardRockOffsets = true;
+        }
     }
 }