Implement taiko relax mod

osu.Game.Rulesets.Taiko/Mods/TaikoModRelax.cs

@@ -5,13 +5,34 @@
 using System.Linq;
 using osu.Framework.Localisation;
 using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Taiko.Objects.Drawables;
 
 namespace osu.Game.Rulesets.Taiko.Mods
 {
-    public class TaikoModRelax : ModRelax
+    public class TaikoModRelax : ModRelax, IApplicableToDrawableHitObject
     {
-        public override LocalisableString Description => @"No ninja-like spinners, demanding drumrolls or unexpected katus.";
+        public override LocalisableString Description => @"No need to remember which key is correct anymore!";
 
         public override Type[] IncompatibleMods => base.IncompatibleMods.Concat(new[] { typeof(TaikoModSingleTap) }).ToArray();
+
+        public void ApplyToDrawableHitObject(DrawableHitObject drawable)
+        {
+            var allActions = Enum.GetValues<TaikoAction>();
+
+            drawable.HitObjectApplied += dho =>
+            {
+                switch (dho)
+                {
+                    case DrawableHit hit:
+                        hit.HitActions = allActions;
+                        break;
+
+                    case DrawableSwell swell:
+                        swell.MustAlternate = false;
+                        break;
+                }
+            };
+        }
     }
 }

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableHit.cs

@@ -22,7 +22,7 @@ public partial class DrawableHit : DrawableTaikoStrongableHitObject<Hit, Hit.Str
         /// <summary>
         /// A list of keys which can result in hits for this HitObject.
         /// </summary>
-        public TaikoAction[] HitActions { get; private set; }
+        public TaikoAction[] HitActions { get; internal set; }
 
         /// <summary>
         /// The action that caused this <see cref="DrawableHit"/> to be hit.

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableSwell.cs

@@ -43,6 +43,11 @@ public partial class DrawableSwell : DrawableTaikoHitObject<Swell>
 
         public override bool DisplayResult => false;
 
+        /// <summary>
+        /// Whether the player must alternate centre and rim hits.
+        /// </summary>
+        public bool MustAlternate { get; internal set; } = true;
+
         public DrawableSwell()
             : this(null)
         {
@@ -292,7 +297,7 @@ public override bool OnPressed(KeyBindingPressEvent<TaikoAction> e)
             bool isCentre = e.Action == TaikoAction.LeftCentre || e.Action == TaikoAction.RightCentre;
 
             // Ensure alternating centre and rim hits
-            if (lastWasCentre == isCentre)
+            if (lastWasCentre == isCentre && MustAlternate)
                 return false;
 
             // If we've already successfully judged a tick this frame, do not judge more.