Add dynamic BPM counter to SkinEditor

osu.Game/Screens/Play/HUD/BPMCounter.cs

@@ -0,0 +1,52 @@
+// 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 osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Graphics;
+using osu.Framework.Localisation;
+using osu.Game.Beatmaps;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Skinning;
+
+namespace osu.Game.Screens.Play.HUD
+{
+    public partial class BPMCounter : RollingCounter<double>, ISkinnableDrawable
+    {
+        [Resolved]
+        private IBindable<WorkingBeatmap> beatmap { get; set; } = null!;
+
+        [Resolved]
+        protected IGameplayClock GameplayClock { get; private set; } = null!;
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colour)
+        {
+            Colour = colour.BlueLighter;
+            Current.Value = DisplayedCount = 0;
+        }
+
+        protected override void Update()
+        {
+            base.Update();
+
+            //We dont want it going to 0 when we pause. so we block the updates
+            if (GameplayClock.IsPaused.Value) return;
+
+            // We want to check Rate every update to cover windup/down
+            Current.Value = beatmap.Value.Beatmap.ControlPointInfo.TimingPointAt(GameplayClock.CurrentTime).BPM * GameplayClock.Rate;
+        }
+
+        protected override OsuSpriteText CreateSpriteText()
+            => base.CreateSpriteText().With(s => s.Font = s.Font.With(size: 20f, fixedWidth: true));
+
+        protected override LocalisableString FormatCount(double count)
+        {
+            return $@"{count:0} BPM";
+        }
+
+        public bool UsesFixedAnchor { get; set; }
+    }
+}