From ac0ed72d043d339a856637a0a3675fe06f5280ee Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Tue, 20 Apr 2021 18:36:11 +0900
Subject: [PATCH] Keep hitcircles aligned with view in "Barrel Roll" mod

---
 .../Mods/OsuModBarrelRoll.cs                  | 25 +++++++++++++++++--
 .../Objects/Drawables/DrawableHitCircle.cs    |  6 ++++-
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/osu.Game.Rulesets.Osu/Mods/OsuModBarrelRoll.cs b/osu.Game.Rulesets.Osu/Mods/OsuModBarrelRoll.cs
index aee431284e..64b87f3977 100644
--- a/osu.Game.Rulesets.Osu/Mods/OsuModBarrelRoll.cs
+++ b/osu.Game.Rulesets.Osu/Mods/OsuModBarrelRoll.cs
@@ -1,20 +1,25 @@
 // 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.Bindables;
 using osu.Framework.Extensions;
 using osu.Framework.Graphics;
 using osu.Game.Configuration;
 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 osu.Game.Rulesets.Osu.UI;
 using osu.Game.Rulesets.UI;
 using osuTK;
 
 namespace osu.Game.Rulesets.Osu.Mods
 {
-    public class OsuModBarrelRoll : Mod, IUpdatableByPlayfield, IApplicableToDrawableRuleset<OsuHitObject>
+    public class OsuModBarrelRoll : Mod, IUpdatableByPlayfield, IApplicableToDrawableRuleset<OsuHitObject>, IApplicableToDrawableHitObjects
     {
+        private float currentRotation;
+
         [SettingSource("Roll speed", "Rotations per minute")]
         public BindableNumber<double> SpinSpeed { get; } = new BindableDouble(0.5)
         {
@@ -35,7 +40,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 
         public void Update(Playfield playfield)
         {
-            playfield.Rotation = (Direction.Value == RotationDirection.Counterclockwise ? -1 : 1) * 360 * (float)(playfield.Time.Current / 60000 * SpinSpeed.Value);
+            playfield.Rotation = currentRotation = (Direction.Value == RotationDirection.Counterclockwise ? -1 : 1) * 360 * (float)(playfield.Time.Current / 60000 * SpinSpeed.Value);
         }
 
         public void ApplyToDrawableRuleset(DrawableRuleset<OsuHitObject> drawableRuleset)
@@ -43,5 +48,21 @@ namespace osu.Game.Rulesets.Osu.Mods
             // scale the playfield to allow all hitobjects to stay within the visible region.
             drawableRuleset.Playfield.Scale = new Vector2(OsuPlayfield.BASE_SIZE.Y / OsuPlayfield.BASE_SIZE.X);
         }
+
+        public void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> drawables)
+        {
+            foreach (var d in drawables)
+            {
+                d.OnUpdate += _ =>
+                {
+                    switch (d)
+                    {
+                        case DrawableHitCircle circle:
+                            circle.CirclePiece.Rotation = -currentRotation;
+                            break;
+                    }
+                };
+            }
+        }
     }
 }
diff --git a/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableHitCircle.cs b/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableHitCircle.cs
index 189003875d..df77ec2693 100644
--- a/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableHitCircle.cs
+++ b/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableHitCircle.cs
@@ -66,7 +66,11 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables
                                 return true;
                             },
                         },
-                        CirclePiece = new SkinnableDrawable(new OsuSkinComponent(CirclePieceComponent), _ => new MainCirclePiece()),
+                        CirclePiece = new SkinnableDrawable(new OsuSkinComponent(CirclePieceComponent), _ => new MainCirclePiece())
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                        },
                         ApproachCircle = new ApproachCircle
                         {
                             Alpha = 0,