Decouple legacy mania combo counter from abstract eldritch entity

osu.Game.Rulesets.Mania/Skinning/Legacy/LegacyManiaComboCounter.cs

@@ -2,9 +2,12 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using System.Globalization;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Rulesets.Scoring;
 using osu.Game.Rulesets.UI.Scrolling;
 using osu.Game.Skinning;
 using osuTK;
@@ -12,17 +15,76 @@
 
 namespace osu.Game.Rulesets.Mania.Skinning.Legacy
 {
-    public partial class LegacyManiaComboCounter : LegacyComboCounter
+    public partial class LegacyManiaComboCounter : CompositeDrawable, ISerialisableDrawable
     {
-        [BackgroundDependencyLoader]
-        private void load(ISkinSource skin)
-        {
-            DisplayedCountText.Anchor = Anchor.Centre;
-            DisplayedCountText.Origin = Anchor.Centre;
+        public bool UsesFixedAnchor { get; set; }
 
-            PopOutCountText.Anchor = Anchor.Centre;
-            PopOutCountText.Origin = Anchor.Centre;
-            PopOutCountText.Colour = skin.GetManiaSkinConfig<Color4>(LegacyManiaSkinConfigurationLookups.ComboBreakColour)?.Value ?? Color4.Red;
+        public Bindable<int> Current { get; } = new BindableInt { MinValue = 0 };
+
+        /// <summary>
+        /// Value shown at the current moment.
+        /// </summary>
+        public virtual int DisplayedCount
+        {
+            get => displayedCount;
+            private set
+            {
+                if (displayedCount.Equals(value))
+                    return;
+
+                displayedCountText.FadeTo(value == 0 ? 0 : 1);
+                displayedCountText.Text = value.ToString(CultureInfo.InvariantCulture);
+                counterContainer.Size = displayedCountText.Size;
+
+                displayedCount = value;
+            }
+        }
+
+        private int displayedCount;
+
+        private int previousValue;
+
+        private const double fade_out_duration = 100;
+        private const double rolling_duration = 20;
+
+        private Container counterContainer = null!;
+        private LegacySpriteText popOutCountText = null!;
+        private LegacySpriteText displayedCountText = null!;
+
+        [BackgroundDependencyLoader]
+        private void load(ISkinSource skin, ScoreProcessor scoreProcessor)
+        {
+            AutoSizeAxes = Axes.Both;
+
+            InternalChildren = new[]
+            {
+                counterContainer = new Container
+                {
+                    AlwaysPresent = true,
+                    Children = new[]
+                    {
+                        popOutCountText = new LegacySpriteText(LegacyFont.Combo)
+                        {
+                            Alpha = 0,
+                            Blending = BlendingParameters.Additive,
+                            BypassAutoSizeAxes = Axes.Both,
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            Colour = skin.GetManiaSkinConfig<Color4>(LegacyManiaSkinConfigurationLookups.ComboBreakColour)?.Value ?? Color4.Red,
+                        },
+                        displayedCountText = new LegacySpriteText(LegacyFont.Combo)
+                        {
+                            Alpha = 0,
+                            AlwaysPresent = true,
+                            BypassAutoSizeAxes = Axes.Both,
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                        },
+                    }
+                }
+            };
+
+            Current.BindTo(scoreProcessor.Combo);
         }
 
         [Resolved]
@@ -34,6 +96,12 @@ protected override void LoadComplete()
         {
             base.LoadComplete();
 
+            displayedCountText.Text = popOutCountText.Text = Current.Value.ToString(CultureInfo.InvariantCulture);
+
+            Current.BindValueChanged(combo => updateCount(combo.NewValue == 0), true);
+
+            counterContainer.Size = displayedCountText.Size;
+
             direction = scrollingInfo.Direction.GetBoundCopy();
             direction.BindValueChanged(_ => updateAnchor());
 
@@ -56,36 +124,71 @@ private void updateAnchor()
             Y = Math.Abs(Y) * (direction.Value == ScrollingDirection.Up ? -1 : 1);
         }
 
-        protected override void OnCountIncrement()
+        private void updateCount(bool rolling)
         {
-            base.OnCountIncrement();
+            int prev = previousValue;
+            previousValue = Current.Value;
 
-            PopOutCountText.Hide();
-            DisplayedCountText.ScaleTo(new Vector2(1f, 1.4f))
+            if (!IsLoaded)
+                return;
+
+            if (!rolling)
+            {
+                FinishTransforms(false, nameof(DisplayedCount));
+
+                if (prev + 1 == Current.Value)
+                    onCountIncrement();
+                else
+                    onCountChange();
+            }
+            else
+                onCountRolling();
+        }
+
+        private void onCountIncrement()
+        {
+            popOutCountText.Hide();
+
+            DisplayedCount = Current.Value;
+            displayedCountText.ScaleTo(new Vector2(1f, 1.4f))
                               .ScaleTo(new Vector2(1f), 300, Easing.Out)
                               .FadeIn(120);
         }
 
-        protected override void OnCountChange()
+        private void onCountChange()
         {
-            base.OnCountChange();
+            popOutCountText.Hide();
 
-            PopOutCountText.Hide();
-            DisplayedCountText.ScaleTo(1f);
+            if (Current.Value == 0)
+                displayedCountText.FadeOut();
+
+            DisplayedCount = Current.Value;
+
+            displayedCountText.ScaleTo(1f);
         }
 
-        protected override void OnCountRolling()
+        private void onCountRolling()
         {
             if (DisplayedCount > 0)
             {
-                PopOutCountText.Text = FormatCount(DisplayedCount);
-                PopOutCountText.FadeTo(0.8f).FadeOut(200)
+                popOutCountText.Text = DisplayedCount.ToString(CultureInfo.InvariantCulture);
+                popOutCountText.FadeTo(0.8f).FadeOut(200)
                                .ScaleTo(1f).ScaleTo(4f, 200);
 
-                DisplayedCountText.FadeTo(0.5f, 300);
+                displayedCountText.FadeTo(0.5f, 300);
             }
 
-            base.OnCountRolling();
+            // Hides displayed count if was increasing from 0 to 1 but didn't finish
+            if (DisplayedCount == 0 && Current.Value == 0)
+                displayedCountText.FadeOut(fade_out_duration);
+
+            this.TransformTo(nameof(DisplayedCount), Current.Value, getProportionalDuration(DisplayedCount, Current.Value));
+        }
+
+        private double getProportionalDuration(int currentValue, int newValue)
+        {
+            double difference = currentValue > newValue ? currentValue - newValue : newValue - currentValue;
+            return difference * rolling_duration;
         }
     }
 }