add interface to adjust DrawableHitObjects

osu.Game.Rulesets.Osu/Mods/OsuMod.cs

@@ -13,6 +13,7 @@
 using osu.Game.Rulesets.Scoring;
 using osu.Game.Rulesets.UI;
 using OpenTK;
+using osu.Game.Rulesets.Objects.Drawables;
 
 namespace osu.Game.Rulesets.Osu.Mods
 {
@@ -26,10 +27,15 @@ public class OsuModEasy : ModEasy
 
     }
 
-    public class OsuModHidden : ModHidden
+    public class OsuModHidden : ModHidden, IApplicableToDrawableHitObjects
     {
         public override string Description => @"Play with no approach circles and fading notes for a slight score advantage.";
         public override double ScoreMultiplier => 1.06;
+
+        public void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> drawables)
+        {
+
+        }
     }
 
     public class OsuModHardRock : ModHardRock, IApplicableToHitObject<OsuHitObject>

osu.Game/Rulesets/Mods/IApplicableToDrawableHitObject.cs

@@ -0,0 +1,24 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using osu.Game.Rulesets.Objects.Drawables;
+
+namespace osu.Game.Rulesets.Mods
+{
+    /// <summary>
+    /// An interface for <see cref="Mod"/>s that can be applied to <see cref="DrawableHitObject"/>s.
+    /// </summary>
+    public interface IApplicableToDrawableHitObjects
+    {
+        /// <summary>
+        /// Applies this <see cref="IApplicableToDrawableHitObjects"/> to a list of <see cref="DrawableHitObject"/>s.
+        /// </summary>
+        /// <param name="drawable">The list of <see cref="DrawableHitObject"/>s to apply to.</param>
+        void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> drawables);
+    }
+}

osu.Game/Rulesets/UI/RulesetContainer.cs

@@ -260,6 +260,9 @@ private void loadObjects()
             }
 
             Playfield.PostProcess();
+
+            foreach (var mod in Mods.OfType<IApplicableToDrawableHitObjects>())
+                mod.ApplyToDrawableHitObjects(Playfield.HitObjects.Objects);
         }
 
         protected override void Update()