Implement partial judgements + make Result non-nullable.

osu.Game.Modes.Osu/Objects/Drawables/DrawableHitCircle.cs

@@ -38,7 +38,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
                     Colour = AccentColour,
                     Hit = () =>
                     {
-                        if (Judgement.Result.HasValue) return false;
+                        if (Judgement.Result != HitResult.None) return false;
 
                         Judgement.PositionOffset = Vector2.Zero; //todo: set to correct value
                         UpdateJudgement(true);

osu.Game.Modes.Taiko/Objects/Drawable/DrawableDrumRollTick.cs

@@ -47,7 +47,7 @@ namespace osu.Game.Modes.Taiko.Objects.Drawable
 
         protected override bool HandleKeyPress(Key key)
         {
-            return !Judgement.Result.HasValue && UpdateJudgement(true);
+            return Judgement.Result == HitResult.None && UpdateJudgement(true);
         }
     }
 }

osu.Game.Modes.Taiko/Objects/Drawable/DrawableHit.cs

@@ -68,7 +68,7 @@ namespace osu.Game.Modes.Taiko.Objects.Drawable
 
         protected override bool HandleKeyPress(Key key)
         {
-            if (Judgement.Result.HasValue)
+            if (Judgement.Result != HitResult.None)
                 return false;
 
             validKeyPressed = HitKeys.Contains(key);

osu.Game.Modes.Taiko/Objects/Drawable/DrawableStrongHit.cs

@@ -5,6 +5,7 @@ using OpenTK.Input;
 using System;
 using System.Linq;
 using osu.Framework.Input;
+using osu.Game.Modes.Objects.Drawables;
 
 namespace osu.Game.Modes.Taiko.Objects.Drawable
 {
@@ -27,7 +28,7 @@ namespace osu.Game.Modes.Taiko.Objects.Drawable
 
         protected override void CheckJudgement(bool userTriggered)
         {
-            if (!Judgement.Result.HasValue)
+            if (Judgement.Result == HitResult.None)
             {
                 base.CheckJudgement(userTriggered);
                 return;
@@ -45,7 +46,7 @@ namespace osu.Game.Modes.Taiko.Objects.Drawable
         protected override bool HandleKeyPress(Key key)
         {
             // Check if we've handled the first key
-            if (!Judgement.Result.HasValue)
+            if (Judgement.Result == HitResult.None)
             {
                 // First key hasn't been handled yet, attempt to handle it
                 bool handled = base.HandleKeyPress(key);

osu.Game.Modes.Taiko/Objects/Drawable/DrawableSwell.cs

@@ -64,7 +64,7 @@ namespace osu.Game.Modes.Taiko.Objects.Drawable
 
         protected override bool HandleKeyPress(Key key)
         {
-            if (Judgement.Result.HasValue)
+            if (Judgement.Result != HitResult.None)
                 return false;
 
             UpdateJudgement(true);

osu.Game/Modes/Judgements/IPartialJudgement.cs

@@ -0,0 +1,26 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using osu.Game.Modes.Objects.Drawables;
+using osu.Game.Modes.Scoring;
+
+namespace osu.Game.Modes.Judgements
+{
+    /// <summary>
+    /// Inidicates that the judgement this is attached to is a partial judgement and the scoring value may change.
+    /// <para>
+    /// This judgement will be continually processed by <see cref="DrawableHitObject{TObject, TJudgement}.CheckJudgement(bool)"/>
+    /// unless the result is a miss and will trigger a full re-process of the <see cref="ScoreProcessor"/> when changed.
+    /// </para>
+    /// </summary>
+    public interface IPartialJudgement
+    {
+        /// <summary>
+        /// Indicates that this partial judgement has changed and requires a full re-process of the <see cref="ScoreProcessor"/>.
+        /// <para>
+        /// This is set to false once the judgement has been re-processed.
+        /// </para>
+        /// </summary>
+        bool Changed { get; set; }
+    }
+}

osu.Game/Modes/Judgements/Judgement.cs

@@ -10,7 +10,7 @@ namespace osu.Game.Modes.Judgements
         /// <summary>
         /// Whether this judgement is the result of a hit or a miss.
         /// </summary>
-        public HitResult? Result;
+        public HitResult Result;
 
         /// <summary>
         /// The offset at which this judgement occurred.

osu.Game/Modes/Objects/Drawables/DrawableHitObject.cs

@@ -93,16 +93,26 @@ namespace osu.Game.Modes.Objects.Drawables
         /// <returns>Whether a hit was processed.</returns>
         protected bool UpdateJudgement(bool userTriggered)
         {
-            if (Judgement.Result != null)
+            IPartialJudgement partial = Judgement as IPartialJudgement;
+
+            // Never re-process non-partial hits, or partial judgements that were previously judged as misses
+            if (Judgement.Result != HitResult.None && (partial == null || Judgement.Result == HitResult.Miss))
                 return false;
 
+            // Update the judgement state
             double endTime = (HitObject as IHasEndTime)?.EndTime ?? HitObject.StartTime;
-
             Judgement.TimeOffset = Time.Current - endTime;
 
+            // Update the judgement state
+            bool hadResult = Judgement.Result != HitResult.None;
             CheckJudgement(userTriggered);
 
-            if (Judgement.Result == null)
+            // Don't process judgements with no result
+            if (Judgement.Result == HitResult.None)
+                return false;
+
+            // Don't process judgements that previously had results but the results were unchanged
+            if (hadResult && partial?.Changed != true)
                 return false;
 
             switch (Judgement.Result)
@@ -117,6 +127,9 @@ namespace osu.Game.Modes.Objects.Drawables
 
             OnJudgement?.Invoke(this);
 
+            if (partial != null)
+                partial.Changed = false;
+
             return true;
         }
 

osu.Game/Modes/Objects/Drawables/HitResult.cs

@@ -7,8 +7,19 @@ namespace osu.Game.Modes.Objects.Drawables
 {
     public enum HitResult
     {
+        /// <summary>
+        /// Indicates that the object has not been judged yet.
+        /// </summary>
+        [Description("")]
+        None,
+        /// <summary>
+        /// Indicates that the object has been judged as a miss.
+        /// </summary>
         [Description(@"Miss")]
         Miss,
+        /// <summary>
+        /// Indicates that the object has been judged as a hit.
+        /// </summary>
         [Description(@"Hit")]
         Hit,
     }

osu.Game/Modes/UI/HitRenderer.cs

@@ -149,7 +149,7 @@ namespace osu.Game.Modes.UI
         public event Action<TJudgement> OnJudgement;
 
         protected override Container<Drawable> Content => content;
-        protected override bool AllObjectsJudged => Playfield.HitObjects.Children.All(h => h.Judgement.Result.HasValue);
+        protected override bool AllObjectsJudged => Playfield.HitObjects.Children.All(h => h.Judgement.Result != HitResult.None);
 
         /// <summary>
         /// The playfield.

osu.Game/osu.Game.csproj

@@ -97,6 +97,7 @@
     <Compile Include="IO\Legacy\SerializationWriter.cs" />
     <Compile Include="IPC\ScoreIPCChannel.cs" />
     <Compile Include="Modes\Judgements\DrawableJudgement.cs" />
+    <Compile Include="Modes\Judgements\IPartialJudgement.cs" />
     <Compile Include="Modes\LegacyReplay.cs" />
     <Compile Include="Modes\Mods\IApplicableMod.cs" />
     <Compile Include="Modes\Mods\ModType.cs" />