Fix legacy hit target being layered incorrectly

osu.Game.Rulesets.Mania/Skinning/LegacyColumnBackground.cs

@@ -1,6 +1,7 @@
 // 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 JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -21,15 +22,20 @@ namespace osu.Game.Rulesets.Mania.Skinning
         private readonly IBindable<ScrollingDirection> direction = new Bindable<ScrollingDirection>();
         private readonly bool isLastColumn;
 
-        private Container borderLineContainer;
+        [CanBeNull]
+        private readonly LegacyStageBackground stageBackground;
+
+        private Container hitTargetContainer;
         private Container lightContainer;
         private Sprite light;
+        private Drawable hitTarget;
 
         private float hitPosition;
 
-        public LegacyColumnBackground(bool isLastColumn)
+        public LegacyColumnBackground(bool isLastColumn, [CanBeNull] LegacyStageBackground stageBackground)
         {
             this.isLastColumn = isLastColumn;
+            this.stageBackground = stageBackground;
             RelativeSizeAxes = Axes.Both;
         }
 
@@ -47,6 +53,7 @@ namespace osu.Game.Rulesets.Mania.Skinning
             bool hasLeftLine = leftLineWidth > 0;
             bool hasRightLine = rightLineWidth > 0 && skin.GetConfig<LegacySkinConfiguration.LegacySetting, decimal>(LegacySkinConfiguration.LegacySetting.Version)?.Value >= 2.4m
                                 || isLastColumn;
+            bool hasHitTarget = Column.Index == 0 || stageBackground == null;
 
             hitPosition = GetColumnSkinConfig<float>(skin, LegacyManiaSkinConfigurationLookups.HitPosition)?.Value
                           ?? Stage.HIT_TARGET_POSITION;
@@ -63,18 +70,29 @@ namespace osu.Game.Rulesets.Mania.Skinning
             Color4 lightColour = GetColumnSkinConfig<Color4>(skin, LegacyManiaSkinConfigurationLookups.ColumnLightColour)?.Value
                                  ?? Color4.White;
 
-            InternalChildren = new Drawable[]
+            Drawable background;
+
+            InternalChildren = new[]
             {
-                new Box
+                background = new Box
                 {
                     RelativeSizeAxes = Axes.Both,
                     Colour = backgroundColour
                 },
-                borderLineContainer = new Container
+                hitTargetContainer = new Container
                 {
                     RelativeSizeAxes = Axes.Both,
                     Children = new[]
                     {
+                        // In legacy skins, the hit target takes on the full stage size and is sandwiched between the column background and the column light.
+                        // To simulate this effect in lazer's hierarchy, the hit target is added to the first column's background and manually extended to the full size of the stage.
+                        // Adding to the first columns allows depth issues to be resolved - if it were added to the last column, the previous column lights would appear below it.
+                        // This still means that the hit target will appear below the next column backgrounds, but that's a much easier problem to solve by proxying the backgrounds below.
+                        hitTarget = new LegacyHitTarget
+                        {
+                            RelativeSizeAxes = Axes.Y,
+                            Alpha = hasHitTarget ? 1 : 0
+                        },
                         new Box
                         {
                             RelativeSizeAxes = Axes.Y,
@@ -113,6 +131,9 @@ namespace osu.Game.Rulesets.Mania.Skinning
                 }
             };
 
+            // Resolve depth issues with the hit target appearing under the next column backgrounds by proxying to the stage background (always below the columns).
+            stageBackground?.AddColumnBackground(background.CreateProxy());
+
             direction.BindTo(scrollingInfo.Direction);
             direction.BindValueChanged(onDirectionChanged, true);
         }
@@ -124,17 +145,23 @@ namespace osu.Game.Rulesets.Mania.Skinning
                 lightContainer.Anchor = Anchor.TopCentre;
                 lightContainer.Scale = new Vector2(1, -1);
 
-                borderLineContainer.Padding = new MarginPadding { Top = hitPosition };
+                hitTargetContainer.Padding = new MarginPadding { Top = hitPosition };
             }
             else
             {
                 lightContainer.Anchor = Anchor.BottomCentre;
                 lightContainer.Scale = Vector2.One;
 
-                borderLineContainer.Padding = new MarginPadding { Bottom = hitPosition };
+                hitTargetContainer.Padding = new MarginPadding { Bottom = hitPosition };
             }
         }
 
+        protected override void Update()
+        {
+            base.Update();
+            hitTarget.Width = stageBackground?.DrawWidth ?? DrawWidth;
+        }
+
         public bool OnPressed(ManiaAction action)
         {
             if (action == Column.Action.Value)

osu.Game.Rulesets.Mania/Skinning/LegacyHitTarget.cs

@@ -20,11 +20,6 @@ namespace osu.Game.Rulesets.Mania.Skinning
 
         private Container directionContainer;
 
-        public LegacyHitTarget()
-        {
-            RelativeSizeAxes = Axes.Both;
-        }
-
         [BackgroundDependencyLoader]
         private void load(ISkinSource skin, IScrollingInfo scrollingInfo)
         {

osu.Game.Rulesets.Mania/Skinning/LegacyStageBackground.cs

@@ -14,6 +14,7 @@ namespace osu.Game.Rulesets.Mania.Skinning
     {
         private Drawable leftSprite;
         private Drawable rightSprite;
+        private Container columnBackgroundContainer;
 
         public LegacyStageBackground()
         {
@@ -44,7 +45,8 @@ namespace osu.Game.Rulesets.Mania.Skinning
                     Origin = Anchor.TopLeft,
                     X = -0.05f,
                     Texture = skin.GetTexture(rightImage)
-                }
+                },
+                columnBackgroundContainer = new Container { RelativeSizeAxes = Axes.Both }
             };
         }
 
@@ -58,5 +60,7 @@ namespace osu.Game.Rulesets.Mania.Skinning
             if (rightSprite?.Height > 0)
                 rightSprite.Scale = new Vector2(1, DrawHeight / rightSprite.Height);
         }
+
+        public void AddColumnBackground(Drawable background) => columnBackgroundContainer.Add(background);
     }
 }

osu.Game.Rulesets.Mania/Skinning/ManiaLegacySkinTransformer.cs

@@ -57,6 +57,8 @@ namespace osu.Game.Rulesets.Mania.Skinning
         /// </summary>
         private Lazy<bool> hasKeyTexture;
 
+        private LegacyStageBackground stageBackground;
+
         public ManiaLegacySkinTransformer(ISkinSource source, IBeatmap beatmap)
             : base(source)
         {
@@ -88,10 +90,11 @@ namespace osu.Game.Rulesets.Mania.Skinning
                     switch (maniaComponent.Component)
                     {
                         case ManiaSkinComponents.ColumnBackground:
-                            return new LegacyColumnBackground(maniaComponent.TargetColumn == beatmap.TotalColumns - 1);
+                            return new LegacyColumnBackground(maniaComponent.TargetColumn == beatmap.TotalColumns - 1, stageBackground);
 
                         case ManiaSkinComponents.HitTarget:
-                            return new LegacyHitTarget();
+                            // Created within the column background, but should not fall back. See comments in LegacyColumnBackground.
+                            return Drawable.Empty();
 
                         case ManiaSkinComponents.KeyArea:
                             return new LegacyKeyArea();
@@ -112,7 +115,7 @@ namespace osu.Game.Rulesets.Mania.Skinning
                             return new LegacyHitExplosion();
 
                         case ManiaSkinComponents.StageBackground:
-                            return new LegacyStageBackground();
+                            return stageBackground = new LegacyStageBackground();
 
                         case ManiaSkinComponents.StageForeground:
                             return new LegacyStageForeground();