add grow mod

osu-resources

@@ -1 +1 @@
-Subproject commit 677897728f4332fa1200e0280ca02c4b987c6c47
+Subproject commit 9880089b4e8fcd78d68f30c8a40d43bf8dccca86

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

@@ -0,0 +1,53 @@
+// 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 System.Collections.Generic;
+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;
+using osu.Game.Rulesets.Osu.Objects.Drawables;
+using osuTK;
+
+namespace osu.Game.Rulesets.Osu.Mods
+{
+    internal class OsuModGrow : Mod, IApplicableToDrawableHitObjects
+    {
+        public override string Name => "Grow";
+        public override string Acronym => "GR";
+        public override FontAwesome Icon => FontAwesome.fa_arrows_v;
+        public override ModType Type => ModType.Fun;
+        public override string Description => "Hit them at the right size!";
+        public override double ScoreMultiplier => 1;
+
+        public void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> drawables)
+        {
+            foreach (var drawable in drawables)
+            {
+                if (drawable is DrawableSpinner spinner)
+                    return;
+                
+                drawable.ApplyCustomUpdateState += applyCustomState;
+            }
+        }
+
+        protected virtual void applyCustomState(DrawableHitObject drawable, ArmedState state)
+        {   
+            var hitObject = (OsuHitObject) drawable.HitObject;
+
+            double appearTime = hitObject.StartTime - hitObject.TimePreempt - 1;
+            double scaleDuration = hitObject.TimePreempt + 1;
+
+            var originalScale = drawable.Scale;
+            drawable.Scale /= 2;
+
+            using (drawable.BeginAbsoluteSequence(appearTime, true))
+                    drawable.ScaleTo(originalScale, scaleDuration, Easing.OutSine);
+
+            if (drawable is DrawableHitCircle circle)
+                using (circle.BeginAbsoluteSequence(hitObject.StartTime - hitObject.TimePreempt))
+                    circle.ApproachCircle.Hide();
+        }
+    }
+}

osu.Game.Rulesets.Osu/OsuRuleset.cs

@@ -124,6 +124,7 @@ namespace osu.Game.Rulesets.Osu
                     return new Mod[] {
                         new OsuModTransform(),
                         new OsuModWiggle(),
+                        new OsuModGrow()
                     };
                 default:
                     return new Mod[] { };