Merge branch 'master' into hold-note-lighting

osu.Game.Rulesets.Mania/ManiaRuleset.cs

@@ -326,6 +326,16 @@ namespace osu.Game.Rulesets.Mania
                         Height = 250
                     }),
                 }
+            },
+            new StatisticRow
+            {
+                Columns = new[]
+                {
+                    new StatisticItem(string.Empty, new SimpleStatisticTable(3, new SimpleStatisticItem[]
+                    {
+                        new UnstableRate(score.HitEvents)
+                    }))
+                }
             }
         };
     }

osu.Game.Rulesets.Mania/Skinning/LegacyKeyArea.cs

@@ -65,6 +65,9 @@ namespace osu.Game.Rulesets.Mania.Skinning
 
             direction.BindTo(scrollingInfo.Direction);
             direction.BindValueChanged(onDirectionChanged, true);
+
+            if (GetColumnSkinConfig<bool>(skin, LegacyManiaSkinConfigurationLookups.KeysUnderNotes)?.Value ?? false)
+                Column.UnderlayElements.Add(CreateProxy());
         }
 
         private void onDirectionChanged(ValueChangedEvent<ScrollingDirection> direction)

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

@@ -79,7 +79,6 @@ namespace osu.Game.Rulesets.Mania.UI
                         columnFlow = new ColumnFlow<Column>(definition)
                         {
                             RelativeSizeAxes = Axes.Y,
-                            Padding = new MarginPadding { Left = COLUMN_SPACING, Right = COLUMN_SPACING },
                         },
                         new Container
                         {

osu.Game.Rulesets.Osu/OsuRuleset.cs

@@ -193,13 +193,18 @@ namespace osu.Game.Rulesets.Osu
 
         public override IRulesetConfigManager CreateConfig(SettingsStore settings) => new OsuRulesetConfigManager(settings, RulesetInfo);
 
-        public override StatisticRow[] CreateStatisticsForScore(ScoreInfo score, IBeatmap playableBeatmap) => new[]
+        public override StatisticRow[] CreateStatisticsForScore(ScoreInfo score, IBeatmap playableBeatmap)
+        {
+            var timedHitEvents = score.HitEvents.Where(e => e.HitObject is HitCircle && !(e.HitObject is SliderTailCircle)).ToList();
+
+            return new[]
             {
                 new StatisticRow
                 {
                     Columns = new[]
                     {
-                    new StatisticItem("Timing Distribution", new HitEventTimingDistributionGraph(score.HitEvents.Where(e => e.HitObject is HitCircle && !(e.HitObject is SliderTailCircle)).ToList())
+                        new StatisticItem("Timing Distribution",
+                            new HitEventTimingDistributionGraph(timedHitEvents)
                             {
                                 RelativeSizeAxes = Axes.X,
                                 Height = 250
@@ -216,7 +221,18 @@ namespace osu.Game.Rulesets.Osu
                             Height = 250
                         }),
                     }
+                },
+                new StatisticRow
+                {
+                    Columns = new[]
+                    {
+                        new StatisticItem(string.Empty, new SimpleStatisticTable(3, new SimpleStatisticItem[]
+                        {
+                            new UnstableRate(timedHitEvents)
+                        }))
+                    }
                 }
             };
         }
     }
+}

osu.Game.Rulesets.Taiko/TaikoRuleset.cs

@@ -161,19 +161,34 @@ namespace osu.Game.Rulesets.Taiko
 
         public override IConvertibleReplayFrame CreateConvertibleReplayFrame() => new TaikoReplayFrame();
 
-        public override StatisticRow[] CreateStatisticsForScore(ScoreInfo score, IBeatmap playableBeatmap) => new[]
+        public override StatisticRow[] CreateStatisticsForScore(ScoreInfo score, IBeatmap playableBeatmap)
+        {
+            var timedHitEvents = score.HitEvents.Where(e => e.HitObject is Hit).ToList();
+
+            return new[]
             {
                 new StatisticRow
                 {
                     Columns = new[]
                     {
-                    new StatisticItem("Timing Distribution", new HitEventTimingDistributionGraph(score.HitEvents.Where(e => e.HitObject is Hit).ToList())
+                        new StatisticItem("Timing Distribution", new HitEventTimingDistributionGraph(timedHitEvents)
                         {
                             RelativeSizeAxes = Axes.X,
                             Height = 250
                         }),
                     }
+                },
+                new StatisticRow
+                {
+                    Columns = new[]
+                    {
+                        new StatisticItem(string.Empty, new SimpleStatisticTable(3, new SimpleStatisticItem[]
+                        {
+                            new UnstableRate(timedHitEvents)
+                        }))
+                    }
                 }
             };
         }
     }
+}

osu.Game.Tests/Beatmaps/Formats/LegacyScoreDecoderTest.cs

@@ -0,0 +1,70 @@
+// 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 System.Collections.Generic;
+using System.Linq;
+using NUnit.Framework;
+using osu.Framework.Utils;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets;
+using osu.Game.Rulesets.Catch;
+using osu.Game.Rulesets.Mania;
+using osu.Game.Rulesets.Osu;
+using osu.Game.Rulesets.Scoring;
+using osu.Game.Rulesets.Taiko;
+using osu.Game.Scoring;
+using osu.Game.Scoring.Legacy;
+using osu.Game.Tests.Resources;
+
+namespace osu.Game.Tests.Beatmaps.Formats
+{
+    [TestFixture]
+    public class LegacyScoreDecoderTest
+    {
+        [Test]
+        public void TestDecodeManiaReplay()
+        {
+            var decoder = new TestLegacyScoreDecoder();
+
+            using (var resourceStream = TestResources.OpenResource("Replays/mania-replay.osr"))
+            {
+                var score = decoder.Parse(resourceStream);
+
+                Assert.AreEqual(3, score.ScoreInfo.Ruleset.ID);
+
+                Assert.AreEqual(2, score.ScoreInfo.Statistics[HitResult.Great]);
+                Assert.AreEqual(1, score.ScoreInfo.Statistics[HitResult.Good]);
+
+                Assert.AreEqual(829_931, score.ScoreInfo.TotalScore);
+                Assert.AreEqual(3, score.ScoreInfo.MaxCombo);
+                Assert.IsTrue(Precision.AlmostEquals(0.8889, score.ScoreInfo.Accuracy, 0.0001));
+                Assert.AreEqual(ScoreRank.B, score.ScoreInfo.Rank);
+
+                Assert.That(score.Replay.Frames, Is.Not.Empty);
+            }
+        }
+
+        private class TestLegacyScoreDecoder : LegacyScoreDecoder
+        {
+            private static readonly Dictionary<int, Ruleset> rulesets = new Ruleset[]
+            {
+                new OsuRuleset(),
+                new TaikoRuleset(),
+                new CatchRuleset(),
+                new ManiaRuleset()
+            }.ToDictionary(ruleset => ((ILegacyRuleset)ruleset).LegacyID);
+
+            protected override Ruleset GetRuleset(int rulesetId) => rulesets[rulesetId];
+
+            protected override WorkingBeatmap GetBeatmap(string md5Hash) => new TestWorkingBeatmap(new Beatmap
+            {
+                BeatmapInfo = new BeatmapInfo
+                {
+                    MD5Hash = md5Hash,
+                    Ruleset = new OsuRuleset().RulesetInfo,
+                    BaseDifficulty = new BeatmapDifficulty()
+                }
+            });
+        }
+    }
+}

osu.Game.Tests/Visual/Ranking/TestSceneSimpleStatisticTable.cs

@@ -0,0 +1,68 @@
+// 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 System.Linq;
+using Humanizer;
+using NUnit.Framework;
+using osu.Framework.Extensions.Color4Extensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+using osu.Framework.Utils;
+using osu.Game.Screens.Ranking.Statistics;
+
+namespace osu.Game.Tests.Visual.Ranking
+{
+    public class TestSceneSimpleStatisticTable : OsuTestScene
+    {
+        private Container container;
+
+        [SetUp]
+        public void SetUp() => Schedule(() =>
+        {
+            Child = new Container
+            {
+                AutoSizeAxes = Axes.Y,
+                Width = 700,
+                Children = new Drawable[]
+                {
+                    new Box
+                    {
+                        RelativeSizeAxes = Axes.Both,
+                        Colour = Color4Extensions.FromHex("#333"),
+                    },
+                    container = new Container
+                    {
+                        RelativeSizeAxes = Axes.X,
+                        AutoSizeAxes = Axes.Y,
+                        Padding = new MarginPadding(20)
+                    }
+                }
+            };
+        });
+
+        [Test]
+        public void TestEmpty()
+        {
+            AddStep("create with no items",
+                () => container.Add(new SimpleStatisticTable(2, Enumerable.Empty<SimpleStatisticItem>())));
+        }
+
+        [Test]
+        public void TestManyItems(
+            [Values(1, 2, 3, 4, 12)] int itemCount,
+            [Values(1, 3, 5)] int columnCount)
+        {
+            AddStep($"create with {"item".ToQuantity(itemCount)}", () =>
+            {
+                var items = Enumerable.Range(1, itemCount)
+                                      .Select(i => new SimpleStatisticItem<int>($"Statistic #{i}")
+                                      {
+                                          Value = RNG.Next(100)
+                                      });
+
+                container.Add(new SimpleStatisticTable(columnCount, items));
+            });
+        }
+    }
+}

osu.Game/Online/Chat/MessageFormatter.cs

@@ -119,7 +119,7 @@ namespace osu.Game.Online.Chat
                 case "http":
                 case "https":
                     // length > 3 since all these links need another argument to work
-                    if (args.Length > 3 && (args[1] == "osu.ppy.sh" || args[1] == "new.ppy.sh"))
+                    if (args.Length > 3 && args[1] == "osu.ppy.sh")
                     {
                         switch (args[2])
                         {

osu.Game/Scoring/Legacy/LegacyScoreDecoder.cs

@@ -13,7 +13,6 @@ using osu.Game.Replays.Legacy;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Replays;
-using osu.Game.Rulesets.Scoring;
 using osu.Game.Users;
 using SharpCompress.Compressors.LZMA;
 
@@ -123,12 +122,12 @@ namespace osu.Game.Scoring.Legacy
 
         protected void CalculateAccuracy(ScoreInfo score)
         {
-            score.Statistics.TryGetValue(HitResult.Miss, out int countMiss);
-            score.Statistics.TryGetValue(HitResult.Meh, out int count50);
-            score.Statistics.TryGetValue(HitResult.Good, out int count100);
-            score.Statistics.TryGetValue(HitResult.Great, out int count300);
-            score.Statistics.TryGetValue(HitResult.Perfect, out int countGeki);
-            score.Statistics.TryGetValue(HitResult.Ok, out int countKatu);
+            int countMiss = score.GetCountMiss() ?? 0;
+            int count50 = score.GetCount50() ?? 0;
+            int count100 = score.GetCount100() ?? 0;
+            int count300 = score.GetCount300() ?? 0;
+            int countGeki = score.GetCountGeki() ?? 0;
+            int countKatu = score.GetCountKatu() ?? 0;
 
             switch (score.Ruleset.ID)
             {
@@ -241,12 +240,15 @@ namespace osu.Game.Scoring.Legacy
                 }
 
                 var diff = Parsing.ParseFloat(split[0]);
+                var mouseX = Parsing.ParseFloat(split[1], Parsing.MAX_COORDINATE_VALUE);
+                var mouseY = Parsing.ParseFloat(split[2], Parsing.MAX_COORDINATE_VALUE);
 
                 lastTime += diff;
 
-                if (i == 0 && diff == 0)
-                    // osu-stable adds a zero-time frame before potentially valid negative user frames.
-                    // we need to ignore this.
+                if (i < 2 && mouseX == 256 && mouseY == -500)
+                    // at the start of the replay, stable places two replay frames, at time 0 and SkipBoundary - 1, respectively.
+                    // both frames use a position of (256, -500).
+                    // ignore these frames as they serve no real purpose (and can even mislead ruleset-specific handlers - see mania)
                     continue;
 
                 // Todo: At some point we probably want to rewind and play back the negative-time frames
@@ -255,8 +257,8 @@ namespace osu.Game.Scoring.Legacy
                     continue;
 
                 currentFrame = convertFrame(new LegacyReplayFrame(lastTime,
-                    Parsing.ParseFloat(split[1], Parsing.MAX_COORDINATE_VALUE),
-                    Parsing.ParseFloat(split[2], Parsing.MAX_COORDINATE_VALUE),
+                    mouseX,
+                    mouseY,
                     (ReplayButtonState)Parsing.ParseInt(split[3])), currentFrame);
 
                 replay.Frames.Add(currentFrame);

osu.Game/Screens/Menu/IntroSequence.cs

@@ -205,6 +205,7 @@ namespace osu.Game.Screens.Menu
                 const int line_end_offset = 120;
 
                 smallRing.Foreground.ResizeTo(1, line_duration, Easing.OutQuint);
+                smallRing.Delay(400).FadeColour(Color4.Black, 300);
 
                 lineTopLeft.MoveTo(new Vector2(-line_end_offset, -line_end_offset), line_duration, Easing.OutQuint);
                 lineTopRight.MoveTo(new Vector2(line_end_offset, -line_end_offset), line_duration, Easing.OutQuint);

osu.Game/Screens/Ranking/Statistics/SimpleStatisticItem.cs

@@ -0,0 +1,81 @@
+// 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.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Game.Graphics;
+using osu.Game.Graphics.Sprites;
+
+namespace osu.Game.Screens.Ranking.Statistics
+{
+    /// <summary>
+    /// Represents a simple statistic item (one that only needs textual display).
+    /// Richer visualisations should be done with <see cref="StatisticItem"/>s.
+    /// </summary>
+    public abstract class SimpleStatisticItem : Container
+    {
+        /// <summary>
+        /// The text to display as the statistic's value.
+        /// </summary>
+        protected string Value
+        {
+            set => this.value.Text = value;
+        }
+
+        private readonly OsuSpriteText value;
+
+        /// <summary>
+        /// Creates a new simple statistic item.
+        /// </summary>
+        /// <param name="name">The name of the statistic.</param>
+        protected SimpleStatisticItem(string name)
+        {
+            Name = name;
+
+            RelativeSizeAxes = Axes.X;
+            AutoSizeAxes = Axes.Y;
+
+            AddRange(new[]
+            {
+                new OsuSpriteText
+                {
+                    Text = Name,
+                    Anchor = Anchor.CentreLeft,
+                    Origin = Anchor.CentreLeft,
+                    Font = OsuFont.GetFont(size: 14)
+                },
+                value = new OsuSpriteText
+                {
+                    Anchor = Anchor.CentreRight,
+                    Origin = Anchor.CentreRight,
+                    Font = OsuFont.GetFont(size: 14, weight: FontWeight.Bold)
+                }
+            });
+        }
+    }
+
+    /// <summary>
+    /// Strongly-typed generic specialisation for <see cref="SimpleStatisticItem"/>.
+    /// </summary>
+    public class SimpleStatisticItem<TValue> : SimpleStatisticItem
+    {
+        /// <summary>
+        /// The statistic's value to be displayed.
+        /// </summary>
+        public new TValue Value
+        {
+            set => base.Value = DisplayValue(value);
+        }
+
+        /// <summary>
+        /// Used to convert <see cref="Value"/> to a text representation.
+        /// Defaults to using <see cref="object.ToString"/>.
+        /// </summary>
+        protected virtual string DisplayValue(TValue value) => value.ToString();
+
+        public SimpleStatisticItem(string name)
+            : base(name)
+        {
+        }
+    }
+}

osu.Game/Screens/Ranking/Statistics/SimpleStatisticTable.cs

@@ -0,0 +1,123 @@
+// 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 System;
+using System.Collections.Generic;
+using System.Linq;
+using JetBrains.Annotations;
+using osu.Framework.Allocation;
+using osu.Framework.Extensions.Color4Extensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
+
+namespace osu.Game.Screens.Ranking.Statistics
+{
+    /// <summary>
+    /// Represents a table with simple statistics (ones that only need textual display).
+    /// Richer visualisations should be done with <see cref="StatisticRow"/>s and <see cref="StatisticItem"/>s.
+    /// </summary>
+    public class SimpleStatisticTable : CompositeDrawable
+    {
+        private readonly SimpleStatisticItem[] items;
+        private readonly int columnCount;
+
+        private FillFlowContainer[] columns;
+
+        /// <summary>
+        /// Creates a statistic row for the supplied <see cref="SimpleStatisticItem"/>s.
+        /// </summary>
+        /// <param name="columnCount">The number of columns to layout the <paramref name="items"/> into.</param>
+        /// <param name="items">The <see cref="SimpleStatisticItem"/>s to display in this row.</param>
+        public SimpleStatisticTable(int columnCount, [ItemNotNull] IEnumerable<SimpleStatisticItem> items)
+        {
+            if (columnCount < 1)
+                throw new ArgumentOutOfRangeException(nameof(columnCount));
+
+            this.columnCount = columnCount;
+            this.items = items.ToArray();
+        }
+
+        [BackgroundDependencyLoader]
+        private void load()
+        {
+            columns = new FillFlowContainer[columnCount];
+
+            RelativeSizeAxes = Axes.X;
+            AutoSizeAxes = Axes.Y;
+
+            InternalChild = new GridContainer
+            {
+                RelativeSizeAxes = Axes.X,
+                AutoSizeAxes = Axes.Y,
+                RowDimensions = new[]
+                {
+                    new Dimension(GridSizeMode.AutoSize)
+                },
+                ColumnDimensions = createColumnDimensions().ToArray(),
+                Content = new[] { createColumns().ToArray() }
+            };
+
+            for (int i = 0; i < items.Length; ++i)
+                columns[i % columnCount].Add(items[i]);
+        }
+
+        private IEnumerable<Dimension> createColumnDimensions()
+        {
+            for (int column = 0; column < columnCount; ++column)
+            {
+                if (column > 0)
+                    yield return new Dimension(GridSizeMode.Absolute, 30);
+
+                yield return new Dimension();
+            }
+        }
+
+        private IEnumerable<Drawable> createColumns()
+        {
+            for (int column = 0; column < columnCount; ++column)
+            {
+                if (column > 0)
+                {
+                    yield return new Spacer
+                    {
+                        Alpha = items.Length > column ? 1 : 0
+                    };
+                }
+
+                yield return columns[column] = createColumn();
+            }
+        }
+
+        private FillFlowContainer createColumn() => new FillFlowContainer
+        {
+            RelativeSizeAxes = Axes.X,
+            AutoSizeAxes = Axes.Y,
+            Direction = FillDirection.Vertical
+        };
+
+        private class Spacer : CompositeDrawable
+        {
+            public Spacer()
+            {
+                RelativeSizeAxes = Axes.Both;
+                Padding = new MarginPadding { Vertical = 4 };
+
+                InternalChild = new CircularContainer
+                {
+                    RelativeSizeAxes = Axes.Y,
+                    Width = 3,
+                    Origin = Anchor.Centre,
+                    Anchor = Anchor.Centre,
+                    CornerRadius = 2,
+                    Masking = true,
+                    Child = new Box
+                    {
+                        RelativeSizeAxes = Axes.Both,
+                        Colour = Color4Extensions.FromHex("#222")
+                    }
+                };
+            }
+        }
+    }
+}

osu.Game/Screens/Ranking/Statistics/StatisticContainer.cs

@@ -32,9 +32,35 @@ namespace osu.Game.Screens.Ranking.Statistics
                 AutoSizeAxes = Axes.Y,
                 Content = new[]
                 {
+                    new[]
+                    {
+                        createHeader(item)
+                    },
                     new Drawable[]
                     {
-                        new FillFlowContainer
+                        new Container
+                        {
+                            RelativeSizeAxes = Axes.X,
+                            AutoSizeAxes = Axes.Y,
+                            Margin = new MarginPadding { Top = 15 },
+                            Child = item.Content
+                        }
+                    },
+                },
+                RowDimensions = new[]
+                {
+                    new Dimension(GridSizeMode.AutoSize),
+                    new Dimension(GridSizeMode.AutoSize),
+                }
+            };
+        }
+
+        private static Drawable createHeader(StatisticItem item)
+        {
+            if (string.IsNullOrEmpty(item.Name))
+                return Empty();
+
+            return new FillFlowContainer
             {
                 RelativeSizeAxes = Axes.X,
                 AutoSizeAxes = Axes.Y,
@@ -58,24 +84,6 @@ namespace osu.Game.Screens.Ranking.Statistics
                         Font = OsuFont.GetFont(size: 14, weight: FontWeight.SemiBold),
                     }
                 }
-                        }
-                    },
-                    new Drawable[]
-                    {
-                        new Container
-                        {
-                            RelativeSizeAxes = Axes.X,
-                            AutoSizeAxes = Axes.Y,
-                            Margin = new MarginPadding { Top = 15 },
-                            Child = item.Content
-                        }
-                    },
-                },
-                RowDimensions = new[]
-                {
-                    new Dimension(GridSizeMode.AutoSize),
-                    new Dimension(GridSizeMode.AutoSize),
-                }
             };
         }
     }

osu.Game/Screens/Ranking/Statistics/StatisticItem.cs

@@ -30,7 +30,7 @@ namespace osu.Game.Screens.Ranking.Statistics
         /// <summary>
         /// Creates a new <see cref="StatisticItem"/>, to be displayed inside a <see cref="StatisticRow"/> in the results screen.
         /// </summary>
-        /// <param name="name">The name of the item.</param>
+        /// <param name="name">The name of the item. Can be <see cref="string.Empty"/> to hide the item header.</param>
         /// <param name="content">The <see cref="Drawable"/> content to be displayed.</param>
         /// <param name="dimension">The <see cref="Dimension"/> of this item. This can be thought of as the column dimension of an encompassing <see cref="GridContainer"/>.</param>
         public StatisticItem([NotNull] string name, [NotNull] Drawable content, [CanBeNull] Dimension dimension = null)

osu.Game/Screens/Ranking/Statistics/StatisticsPanel.cs

@@ -94,14 +94,15 @@ namespace osu.Game.Screens.Ranking.Statistics
                         RelativeSizeAxes = Axes.Both,
                         Direction = FillDirection.Vertical,
                         Spacing = new Vector2(30, 15),
+                        Alpha = 0
                     };
 
                     foreach (var row in newScore.Ruleset.CreateInstance().CreateStatisticsForScore(newScore, playableBeatmap))
                     {
                         rows.Add(new GridContainer
                         {
-                            Anchor = Anchor.Centre,
-                            Origin = Anchor.Centre,
+                            Anchor = Anchor.TopCentre,
+                            Origin = Anchor.TopCentre,
                             RelativeSizeAxes = Axes.X,
                             AutoSizeAxes = Axes.Y,
                             Content = new[]
@@ -125,6 +126,7 @@ namespace osu.Game.Screens.Ranking.Statistics
 
                         spinner.Hide();
                         content.Add(d);
+                        d.FadeIn(250, Easing.OutQuint);
                     }, localCancellationSource.Token);
                 }), localCancellationSource.Token);
             }

osu.Game/Screens/Ranking/Statistics/UnstableRate.cs

@@ -0,0 +1,39 @@
+// 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 System;
+using System.Collections.Generic;
+using System.Linq;
+using osu.Game.Rulesets.Scoring;
+
+namespace osu.Game.Screens.Ranking.Statistics
+{
+    /// <summary>
+    /// Displays the unstable rate statistic for a given play.
+    /// </summary>
+    public class UnstableRate : SimpleStatisticItem<double>
+    {
+        /// <summary>
+        /// Creates and computes an <see cref="UnstableRate"/> statistic.
+        /// </summary>
+        /// <param name="hitEvents">Sequence of <see cref="HitEvent"/>s to calculate the unstable rate based on.</param>
+        public UnstableRate(IEnumerable<HitEvent> hitEvents)
+            : base("Unstable Rate")
+        {
+            var timeOffsets = hitEvents.Select(ev => ev.TimeOffset).ToArray();
+            Value = 10 * standardDeviation(timeOffsets);
+        }
+
+        private static double standardDeviation(double[] timeOffsets)
+        {
+            if (timeOffsets.Length == 0)
+                return double.NaN;
+
+            var mean = timeOffsets.Average();
+            var squares = timeOffsets.Select(offset => Math.Pow(offset - mean, 2)).Sum();
+            return Math.Sqrt(squares / timeOffsets.Length);
+        }
+
+        protected override string DisplayValue(double value) => double.IsNaN(value) ? "(not available)" : value.ToString("N2");
+    }
+}

osu.Game/Skinning/LegacyManiaSkinConfiguration.cs

@@ -36,6 +36,7 @@ namespace osu.Game.Skinning
         public float HitPosition = (480 - 402) * POSITION_SCALE_FACTOR;
         public float LightPosition = (480 - 413) * POSITION_SCALE_FACTOR;
         public bool ShowJudgementLine = true;
+        public bool KeysUnderNotes;
 
         public LegacyManiaSkinConfiguration(int keys)
         {

osu.Game/Skinning/LegacyManiaSkinConfigurationLookup.cs

@@ -52,5 +52,6 @@ namespace osu.Game.Skinning
         Hit100,
         Hit50,
         Hit0,
+        KeysUnderNotes,
     }
 }

osu.Game/Skinning/LegacyManiaSkinDecoder.cs

@@ -97,6 +97,10 @@ namespace osu.Game.Skinning
                         currentConfig.ShowJudgementLine = pair.Value == "1";
                         break;
 
+                    case "KeysUnderNotes":
+                        currentConfig.KeysUnderNotes = pair.Value == "1";
+                        break;
+
                     case "LightingNWidth":
                         parseArrayValue(pair.Value, currentConfig.ExplosionWidth);
                         break;

osu.Game/Skinning/LegacySkin.cs

@@ -272,6 +272,9 @@ namespace osu.Game.Skinning
                 case LegacyManiaSkinConfigurationLookups.Hit300:
                 case LegacyManiaSkinConfigurationLookups.Hit300g:
                     return SkinUtils.As<TValue>(getManiaImage(existing, maniaLookup.Lookup.ToString()));
+
+                case LegacyManiaSkinConfigurationLookups.KeysUnderNotes:
+                    return SkinUtils.As<TValue>(new Bindable<bool>(existing.KeysUnderNotes));
             }
 
             return null;