Increase visibility of osu!mania long notes

osu.Game.Rulesets.Mania/Objects/Drawables/DrawableHoldNote.cs

@@ -111,6 +111,18 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
             bodyPiece.Height = DrawHeight - Head.Height / 2 + Tail.Height / 2;
         }
 
+        protected void BeginHold()
+        {
+            holdStartTime = Time.Current;
+            bodyPiece.Hitting = true;
+        }
+
+        protected void EndHold()
+        {
+            holdStartTime = null;
+            bodyPiece.Hitting = false;
+        }
+
         public bool OnPressed(ManiaAction action)
         {
             // Make sure the action happened within the body of the hold note
@@ -123,8 +135,7 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
             // The user has pressed during the body of the hold note, after the head note and its hit windows have passed
             // and within the limited range of the above if-statement. This state will be managed by the head note if the
             // user has pressed during the hit windows of the head note.
-            holdStartTime = Time.Current;
-
+            BeginHold();
             return true;
         }
 
@@ -137,7 +148,7 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
             if (action != Action.Value)
                 return false;
 
-            holdStartTime = null;
+            EndHold();
 
             // If the key has been released too early, the user should not receive full score for the release
             if (!Tail.IsHit)
@@ -170,7 +181,7 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables
 
                 // The head note also handles early hits before the body, but we want accurate early hits to count as the body being held
                 // The body doesn't handle these early early hits, so we have to explicitly set the holding state here
-                holdNote.holdStartTime = Time.Current;
+                holdNote.BeginHold();
 
                 return true;
             }

osu.Game.Rulesets.Mania/Objects/Drawables/Pieces/BodyPiece.cs

@@ -32,6 +32,7 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables.Pieces
                 background = new Box { RelativeSizeAxes = Axes.Both },
                 foreground = new BufferedContainer
                 {
+                    Blending = BlendingMode.Additive,
                     RelativeSizeAxes = Axes.Both,
                     CacheDrawnFrameBuffer = true,
                     Children = new Drawable[]
@@ -73,6 +74,7 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables.Pieces
         }
 
         private Color4 accentColour;
+
         public Color4 AccentColour
         {
             get { return accentColour; }
@@ -86,6 +88,16 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables.Pieces
             }
         }
 
+        public bool Hitting
+        {
+            get { return hitting; }
+            set
+            {
+                hitting = value;
+                updateAccentColour();
+            }
+        }
+
         private Cached subtractionCache = new Cached();
 
         public override bool Invalidate(Invalidation invalidation = Invalidation.All, Drawable source = null, bool shallPropagate = true)
@@ -118,13 +130,22 @@ namespace osu.Game.Rulesets.Mania.Objects.Drawables.Pieces
             }
         }
 
+        private bool hitting;
+
         private void updateAccentColour()
         {
             if (!IsLoaded)
                 return;
 
-            foreground.Colour = AccentColour.Opacity(0.9f);
-            background.Colour = AccentColour.Opacity(0.6f);
+            foreground.Colour = AccentColour.Opacity(0.5f);
+            background.Colour = AccentColour.Opacity(0.7f);
+
+            if (hitting)
+                foreground.FadeColour(AccentColour.Lighten(0.3f), 50).Then().FadeColour(foreground.Colour, 50).Loop();
+            else
+            {
+                foreground.ClearTransforms(false, nameof(foreground.Colour));
+            }
 
             subtractionCache.Invalidate();
         }