Implement SpeedAdjustedPlayfield and a new HitRenderer derivation.

osu.Game.Rulesets.Mania/UI/ManiaHitRenderer.cs

@@ -30,7 +30,7 @@ using osu.Game.Rulesets.UI;
 
 namespace osu.Game.Rulesets.Mania.UI
 {
-    public class ManiaHitRenderer : SpeedAdjustedHitRenderer<ManiaHitObject, ManiaJudgement>
+    public class ManiaHitRenderer : SpeedAdjustedHitRenderer<ManiaPlayfield, ManiaHitObject, ManiaJudgement>
     {
         /// <summary>
         /// Preferred column count. This will only have an effect during the initialization of the play field.

osu.Game.Rulesets.Mania/UI/ManiaPlayfield.cs

@@ -23,7 +23,7 @@ using osu.Framework.Graphics.Shapes;
 
 namespace osu.Game.Rulesets.Mania.UI
 {
-    public class ManiaPlayfield : Playfield<ManiaHitObject, ManiaJudgement>
+    public class ManiaPlayfield : SpeedAdjustedPlayfield<ManiaHitObject, ManiaJudgement>
     {
         public const float HIT_TARGET_POSITION = 50;
 

osu.Game/Rulesets/UI/HitRenderer.cs

@@ -221,7 +221,7 @@ namespace osu.Game.Rulesets.UI
         /// <summary>
         /// The playfield.
         /// </summary>
-        protected Playfield<TObject, TJudgement> Playfield;
+        protected Playfield<TObject, TJudgement> Playfield { get; private set; }
 
         protected override Container<Drawable> Content => content;
         private readonly Container content;
@@ -319,6 +319,32 @@ namespace osu.Game.Rulesets.UI
         protected abstract Playfield<TObject, TJudgement> CreatePlayfield();
     }
 
+    /// <summary>
+    /// A derivable HitRenderer that manages the Playfield and HitObjects.
+    /// </summary>
+    /// <typeparam name="TObject">The type of HitObject contained by this HitRenderer.</typeparam>
+    /// <typeparam name="TJudgement">The type of Judgement of DrawableHitObjects contained by this HitRenderer.</typeparam>
+    public abstract class HitRenderer<TPlayfield, TObject, TJudgement> : HitRenderer<TObject, TJudgement>
+        where TObject : HitObject
+        where TJudgement : Judgement
+        where TPlayfield : Playfield<TObject, TJudgement>
+    {
+        /// <summary>
+        /// The playfield.
+        /// </summary>
+        protected new TPlayfield Playfield => (TPlayfield)base.Playfield;
+
+        /// <summary>
+        /// Creates a hit renderer for a beatmap.
+        /// </summary>
+        /// <param name="beatmap">The beatmap to create the hit renderer for.</param>
+        /// <param name="isForCurrentRuleset">Whether to assume the beatmap is for the current ruleset.</param>
+        protected HitRenderer(WorkingBeatmap beatmap, bool isForCurrentRuleset)
+            : base(beatmap, isForCurrentRuleset)
+        {
+        }
+    }
+
     public class BeatmapInvalidForRulesetException : ArgumentException
     {
         public BeatmapInvalidForRulesetException(string text)

osu.Game/Rulesets/UI/SpeedAdjustedHitRenderer.cs

@@ -16,11 +16,13 @@ using osu.Game.Rulesets.Timing;
 namespace osu.Game.Rulesets.UI
 {
     /// <summary>
-    /// A type of <see cref="HitRenderer{TObject, TJudgement}"/> that supports speed adjustments in some capacity.
+    /// A type of <see cref="HitRenderer{TObject, TJudgement}"/> that exposes <see cref="MultiplierControlPoint"/>s to be used
+    /// in <see cref="SpeedAdjustmentCollection"/>s.
     /// </summary>
-    public abstract class SpeedAdjustedHitRenderer<TObject, TJudgement> : HitRenderer<TObject, TJudgement>
+    public abstract class SpeedAdjustedHitRenderer<TPlayfield, TObject, TJudgement> : HitRenderer<TPlayfield, TObject, TJudgement>
         where TObject : HitObject
         where TJudgement : Judgement
+        where TPlayfield : SpeedAdjustedPlayfield<TObject, TJudgement>
     {
         protected readonly SortedList<MultiplierControlPoint> DefaultControlPoints = new SortedList<MultiplierControlPoint>(Comparer<MultiplierControlPoint>.Default);
 

osu.Game/Rulesets/UI/SpeedAdjustedPlayfield.cs

@@ -0,0 +1,15 @@
+using osu.Game.Rulesets.Judgements;
+using osu.Game.Rulesets.Objects;
+
+namespace osu.Game.Rulesets.UI
+{
+    public class SpeedAdjustedPlayfield<TObject, TJudgement> : Playfield<TObject, TJudgement>
+        where TObject : HitObject
+        where TJudgement : Judgement
+    {
+        protected SpeedAdjustedPlayfield(float? customWidth = null)
+            : base(customWidth)
+        {
+        }
+    }
+}

osu.Game/osu.Game.csproj

@@ -340,6 +340,7 @@
     <Compile Include="Rulesets\UI\HitRenderer.cs" />
     <Compile Include="Rulesets\UI\Playfield.cs" />
     <Compile Include="Rulesets\UI\SpeedAdjustedHitRenderer.cs" />
+    <Compile Include="Rulesets\UI\SpeedAdjustedPlayfield.cs" />
     <Compile Include="Screens\Select\EditSongSelect.cs" />
     <Compile Include="Screens\Play\HUD\ComboCounter.cs" />
     <Compile Include="Screens\Play\HUD\ComboResultCounter.cs" />