Added OsuModDeflate class and adjusted OsuRuleset.cs

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

@@ -0,0 +1,44 @@
+// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using osu.Framework.Graphics;
+using osu.Game.Graphics;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Osu.Objects.Drawables;
+using System.Collections.Generic;
+
+namespace osu.Game.Rulesets.Osu.Mods
+{
+    public class OsuModDeflate : Mod, IApplicableToDrawableHitObjects
+    {
+        public override string Name => "Deflate";
+        public override string ShortenedName => "DF";
+        public override FontAwesome Icon => FontAwesome.fa_compress;
+        public override ModType Type => ModType.Fun;
+        public override string Description => "Become one with the approach circle...";
+        public override double ScoreMultiplier => 1;
+
+        public void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> drawables)
+        {
+            foreach (var drawable in drawables)
+                drawable.ApplyCustomUpdateState += drawableOnApplyCustomUpdateState;
+        }
+
+        protected void drawableOnApplyCustomUpdateState(DrawableHitObject drawable, ArmedState state)
+        {
+            if (!(drawable is DrawableHitCircle d))
+                return;
+            
+            d.ApproachCircle.Hide();
+            var h = d.HitObject;
+
+            using (d.BeginAbsoluteSequence(h.StartTime - h.TimePreempt))
+            {
+                var origScale = d.Scale;
+                d.ScaleTo(1.1f);
+                d.ScaleTo(origScale, h.TimePreempt);
+            }
+        }
+    }
+}

osu.Game.Rulesets.Osu/OsuRuleset.cs

@@ -117,6 +117,11 @@ namespace osu.Game.Rulesets.Osu
                         new OsuModRelax(),
                         new OsuModAutopilot(),
                     };
+                case ModType.Fun:
+                    return new Mod[]
+                    {
+                        new OsuModDeflate(),
+                    };
                 default:
                     return new Mod[] { };
             }