Merge https://github.com/ppy/osu into auto-restart-mod-perfect

appveyor_deploy.yml

@@ -10,8 +10,8 @@ before_build:
   - cmd: nuget restore -verbosity quiet
 build_script:
   - ps: iex ((New-Object Net.WebClient).DownloadString('https://raw.githubusercontent.com/appveyor/secure-file/master/install.ps1'))
-  - appveyor DownloadFile https://puu.sh/BCrS8/7faccf7876.enc # signing certificate
-  - cmd: appveyor-tools\secure-file -decrypt 7faccf7876.enc -secret %decode_secret% -out %HOMEPATH%\deanherbert.pfx
+  - appveyor DownloadFile https://www.dropbox.com/s/f7hv069mr5tqi2j/deanherbert.pfx.enc?dl=1 # signing certificate
+  - cmd: appveyor-tools\secure-file -decrypt deanherbert.pfx.enc -secret %decode_secret% -out %HOMEPATH%\deanherbert.pfx
   - appveyor DownloadFile https://puu.sh/A6g75/fdc6f19b04.enc # deploy configuration
   - cd osu-deploy
   - nuget restore -verbosity quiet

osu.Desktop/osu.Desktop.csproj

@@ -27,7 +27,7 @@
   </ItemGroup>
   <ItemGroup Label="Package References">
     <PackageReference Include="System.IO.Packaging" Version="4.5.0" />
-    <PackageReference Include="ppy.squirrel.windows" Version="1.8.0.8" />
+    <PackageReference Include="ppy.squirrel.windows" Version="1.9.0.1" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="2.1.4" />
   </ItemGroup>

osu.Game.Rulesets.Catch.Tests/TestCaseAutoJuiceStream.cs

@@ -1,7 +1,6 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
-using System.Collections.Generic;
 using System.Linq;
 using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Catch.Objects;
@@ -38,7 +37,7 @@ namespace osu.Game.Rulesets.Catch.Tests
                 beatmap.HitObjects.Add(new JuiceStream
                 {
                     X = 0.5f - width / 2,
-                    ControlPoints = new List<Vector2>
+                    ControlPoints = new[]
                     {
                         Vector2.Zero,
                         new Vector2(width * CatchPlayfield.BASE_WIDTH, 0)

osu.Game.Rulesets.Catch/Objects/JuiceStream.cs

@@ -146,7 +146,7 @@ namespace osu.Game.Rulesets.Catch.Objects
 
         public SliderCurve Curve { get; } = new SliderCurve();
 
-        public List<Vector2> ControlPoints
+        public Vector2[] ControlPoints
         {
             get { return Curve.ControlPoints; }
             set { Curve.ControlPoints = value; }

osu.Game.Rulesets.Mania/Beatmaps/ManiaBeatmapConverter.cs

@@ -48,7 +48,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
                 TargetColumns = (int)Math.Max(1, roundedCircleSize);
             else
             {
-                float percentSliderOrSpinner = (float)beatmap.HitObjects.Count(h => h is IHasEndTime) / beatmap.HitObjects.Count();
+                float percentSliderOrSpinner = (float)beatmap.HitObjects.Count(h => h is IHasEndTime) / beatmap.HitObjects.Count;
                 if (percentSliderOrSpinner < 0.2)
                     TargetColumns = 7;
                 else if (percentSliderOrSpinner < 0.3 || roundedCircleSize >= 5)

osu.Game.Rulesets.Mania/Beatmaps/Patterns/Legacy/PatternGenerator.cs

@@ -112,7 +112,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
                     drainTime = 10000;
 
                 BeatmapDifficulty difficulty = OriginalBeatmap.BeatmapInfo.BaseDifficulty;
-                conversionDifficulty = ((difficulty.DrainRate + MathHelper.Clamp(difficulty.ApproachRate, 4, 7)) / 1.5 + (double)OriginalBeatmap.HitObjects.Count() / drainTime * 9f) / 38f * 5f / 1.15;
+                conversionDifficulty = ((difficulty.DrainRate + MathHelper.Clamp(difficulty.ApproachRate, 4, 7)) / 1.5 + (double)OriginalBeatmap.HitObjects.Count / drainTime * 9f) / 38f * 5f / 1.15;
                 conversionDifficulty = Math.Min(conversionDifficulty.Value, 12);
 
                 return conversionDifficulty.Value;

osu.Game.Rulesets.Osu.Tests/TestCaseSlider.cs

@@ -108,7 +108,7 @@ namespace osu.Game.Rulesets.Osu.Tests
             {
                 StartTime = Time.Current + 1000,
                 Position = new Vector2(239, 176),
-                ControlPoints = new List<Vector2>
+                ControlPoints = new[]
                 {
                     Vector2.Zero,
                     new Vector2(154, 28),
@@ -141,7 +141,7 @@ namespace osu.Game.Rulesets.Osu.Tests
             {
                 StartTime = Time.Current + 1000,
                 Position = new Vector2(-(distance / 2), 0),
-                ControlPoints = new List<Vector2>
+                ControlPoints = new[]
                 {
                     Vector2.Zero,
                     new Vector2(distance, 0),
@@ -161,7 +161,7 @@ namespace osu.Game.Rulesets.Osu.Tests
             {
                 StartTime = Time.Current + 1000,
                 Position = new Vector2(-200, 0),
-                ControlPoints = new List<Vector2>
+                ControlPoints = new[]
                 {
                     Vector2.Zero,
                     new Vector2(200, 200),
@@ -184,7 +184,7 @@ namespace osu.Game.Rulesets.Osu.Tests
                 CurveType = CurveType.Linear,
                 StartTime = Time.Current + 1000,
                 Position = new Vector2(-200, 0),
-                ControlPoints = new List<Vector2>
+                ControlPoints = new[]
                 {
                     Vector2.Zero,
                     new Vector2(150, 75),
@@ -210,7 +210,7 @@ namespace osu.Game.Rulesets.Osu.Tests
                 CurveType = CurveType.Bezier,
                 StartTime = Time.Current + 1000,
                 Position = new Vector2(-200, 0),
-                ControlPoints = new List<Vector2>
+                ControlPoints = new[]
                 {
                     Vector2.Zero,
                     new Vector2(150, 75),
@@ -235,7 +235,7 @@ namespace osu.Game.Rulesets.Osu.Tests
                 CurveType = CurveType.Linear,
                 StartTime = Time.Current + 1000,
                 Position = new Vector2(0, 0),
-                ControlPoints = new List<Vector2>
+                ControlPoints = new[]
                 {
                     Vector2.Zero,
                     new Vector2(-200, 0),
@@ -265,7 +265,7 @@ namespace osu.Game.Rulesets.Osu.Tests
                 StartTime = Time.Current + 1000,
                 Position = new Vector2(-100, 0),
                 CurveType = CurveType.Catmull,
-                ControlPoints = new List<Vector2>
+                ControlPoints = new[]
                 {
                     Vector2.Zero,
                     new Vector2(50, -50),

osu.Game.Rulesets.Osu/Difficulty/OsuDifficultyCalculator.cs

@@ -65,7 +65,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty
             double hitWindowGreat = (int)(beatmap.HitObjects.First().HitWindows.Great / 2) / timeRate;
             double preempt = (int)BeatmapDifficulty.DifficultyRange(beatmap.BeatmapInfo.BaseDifficulty.ApproachRate, 1800, 1200, 450) / timeRate;
 
-            int maxCombo = beatmap.HitObjects.Count();
+            int maxCombo = beatmap.HitObjects.Count;
             // Add the ticks + tail of the slider. 1 is subtracted because the head circle would be counted twice (once for the slider itself in the line above)
             maxCombo += beatmap.HitObjects.OfType<Slider>().Sum(s => s.NestedHitObjects.Count - 1);
 

osu.Game.Rulesets.Osu/Difficulty/OsuPerformanceCalculator.cs

@@ -34,7 +34,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty
         {
             countHitCircles = Beatmap.HitObjects.Count(h => h is HitCircle);
 
-            beatmapMaxCombo = Beatmap.HitObjects.Count();
+            beatmapMaxCombo = Beatmap.HitObjects.Count;
             // Add the ticks + tail of the slider. 1 is subtracted because the "headcircle" would be counted twice (once for the slider itself in the line above)
             beatmapMaxCombo += Beatmap.HitObjects.OfType<Slider>().Sum(s => s.NestedHitObjects.Count - 1);
         }

osu.Game.Rulesets.Osu/Mods/OsuModHardRock.cs

@@ -1,7 +1,6 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
-using System.Collections.Generic;
 using System.Linq;
 using osu.Framework.Extensions.IEnumerableExtensions;
 using osu.Game.Rulesets.Mods;
@@ -33,8 +32,9 @@ namespace osu.Game.Rulesets.Osu.Mods
             slider.NestedHitObjects.OfType<SliderTick>().ForEach(h => h.Position = new Vector2(h.Position.X, OsuPlayfield.BASE_SIZE.Y - h.Position.Y));
             slider.NestedHitObjects.OfType<RepeatPoint>().ForEach(h => h.Position = new Vector2(h.Position.X, OsuPlayfield.BASE_SIZE.Y - h.Position.Y));
 
-            var newControlPoints = new List<Vector2>();
-            slider.ControlPoints.ForEach(c => newControlPoints.Add(new Vector2(c.X, -c.Y)));
+            var newControlPoints = new Vector2[slider.ControlPoints.Length];
+            for (int i = 0; i < slider.ControlPoints.Length; i++)
+                newControlPoints[i] = new Vector2(slider.ControlPoints[i].X, -slider.ControlPoints[i].Y);
 
             slider.ControlPoints = newControlPoints;
             slider.Curve?.Calculate(); // Recalculate the slider curve

osu.Game.Rulesets.Osu/Objects/Slider.cs

@@ -52,7 +52,7 @@ namespace osu.Game.Rulesets.Osu.Objects
 
         public SliderCurve Curve { get; } = new SliderCurve();
 
-        public List<Vector2> ControlPoints
+        public Vector2[] ControlPoints
         {
             get { return Curve.ControlPoints; }
             set { Curve.ControlPoints = value; }

osu.Game.Tests/Visual/TestCaseHitObjectComposer.cs

@@ -44,7 +44,7 @@ namespace osu.Game.Tests.Visual
                     new Slider
                     {
                         Position = new Vector2(128, 256),
-                        ControlPoints = new List<Vector2>
+                        ControlPoints = new[]
                         {
                             Vector2.Zero,
                             new Vector2(216, 0),

osu.Game.props

@@ -1,7 +1,7 @@
 <!-- Contains required properties for osu!framework projects. -->
 <Project>
   <PropertyGroup Label="C#">
-    <LangVersion>7</LangVersion>
+    <LangVersion>7.2</LangVersion>
   </PropertyGroup>
   <PropertyGroup>
     <ApplicationManifest>..\app.manifest</ApplicationManifest>

osu.Game/Beatmaps/Beatmap.cs

@@ -48,7 +48,7 @@ namespace osu.Game.Beatmaps
         [JsonConverter(typeof(TypedListConverter<HitObject>))]
         public List<T> HitObjects = new List<T>();
 
-        IEnumerable<HitObject> IBeatmap.HitObjects => HitObjects;
+        IReadOnlyList<HitObject> IBeatmap.HitObjects => HitObjects;
 
         public virtual IEnumerable<BeatmapStatistic> GetStatistics() => Enumerable.Empty<BeatmapStatistic>();
 

osu.Game/Beatmaps/BeatmapConverter.cs

@@ -55,39 +55,40 @@ namespace osu.Game.Beatmaps
 
             beatmap.BeatmapInfo = original.BeatmapInfo;
             beatmap.ControlPointInfo = original.ControlPointInfo;
-            beatmap.HitObjects = original.HitObjects.SelectMany(h => convert(h, original)).ToList();
+            beatmap.HitObjects = convertHitObjects(original.HitObjects, original);
             beatmap.Breaks = original.Breaks;
 
             return beatmap;
         }
 
-        /// <summary>
-        /// Converts a hit object.
-        /// </summary>
-        /// <param name="original">The hit object to convert.</param>
-        /// <param name="beatmap">The un-converted Beatmap.</param>
-        /// <returns>The converted hit object.</returns>
-        private IEnumerable<T> convert(HitObject original, IBeatmap beatmap)
+        private List<T> convertHitObjects(IReadOnlyList<HitObject> hitObjects, IBeatmap beatmap)
         {
-            // Check if the hitobject is already the converted type
-            T tObject = original as T;
-            if (tObject != null)
-            {
-                yield return tObject;
-                yield break;
-            }
+            var result = new List<T>(hitObjects.Count);
 
-            var converted = ConvertHitObject(original, beatmap).ToList();
-            ObjectConverted?.Invoke(original, converted);
-
-            // Convert the hit object
-            foreach (var obj in converted)
+            foreach (var obj in hitObjects)
             {
-                if (obj == null)
+                if (obj is T tObj)
+                {
+                    result.Add(tObj);
                     continue;
+                }
 
-                yield return obj;
+                var converted = ConvertHitObject(obj, beatmap);
+
+                if (ObjectConverted != null)
+                {
+                    converted = converted.ToList();
+                    ObjectConverted.Invoke(obj, converted);
+                }
+
+                foreach (var c in converted)
+                {
+                    if (c != null)
+                        result.Add(c);
+                }
             }
+
+            return result;
         }
 
         /// <summary>

osu.Game/Beatmaps/ControlPoints/ControlPointInfo.cs

@@ -55,14 +55,14 @@ namespace osu.Game.Beatmaps.ControlPoints
         /// </summary>
         /// <param name="time">The time to find the sound control point at.</param>
         /// <returns>The sound control point.</returns>
-        public SampleControlPoint SamplePointAt(double time) => binarySearch(SamplePoints, time, SamplePoints.FirstOrDefault());
+        public SampleControlPoint SamplePointAt(double time) => binarySearch(SamplePoints, time, SamplePoints.Count > 0 ? SamplePoints[0] : null);
 
         /// <summary>
         /// Finds the timing control point that is active at <paramref name="time"/>.
         /// </summary>
         /// <param name="time">The time to find the timing control point at.</param>
         /// <returns>The timing control point.</returns>
-        public TimingControlPoint TimingPointAt(double time) => binarySearch(TimingPoints, time, TimingPoints.FirstOrDefault());
+        public TimingControlPoint TimingPointAt(double time) => binarySearch(TimingPoints, time, TimingPoints.Count > 0 ? TimingPoints[0] : null);
 
         /// <summary>
         /// Finds the maximum BPM represented by any timing control point.
@@ -104,17 +104,26 @@ namespace osu.Game.Beatmaps.ControlPoints
             if (time < list[0].Time)
                 return prePoint ?? new T();
 
-            int index = list.BinarySearch(new T { Time = time });
+            if (time >= list[list.Count - 1].Time)
+                return list[list.Count - 1];
 
-            // Check if we've found an exact match (t == time)
-            if (index >= 0)
-                return list[index];
+            int l = 0;
+            int r = list.Count - 2;
 
-            index = ~index;
+            while (l <= r)
+            {
+                int pivot = l + ((r - l) >> 1);
 
-            // BinarySearch will return the index of the first element _greater_ than the search
-            // This is the inactive point - the active point is the one before it (index - 1)
-            return list[index - 1];
+                if (list[pivot].Time < time)
+                    l = pivot + 1;
+                else if (list[pivot].Time > time)
+                    r = pivot - 1;
+                else
+                    return list[pivot];
+            }
+
+            // l will be the first control point with Time > time, but we want the one before it
+            return list[l - 1];
         }
     }
 }

osu.Game/Beatmaps/Formats/LegacyBeatmapDecoder.cs

@@ -58,7 +58,7 @@ namespace osu.Game.Beatmaps.Formats
                 hitObject.ApplyDefaults(this.beatmap.ControlPointInfo, this.beatmap.BeatmapInfo.BaseDifficulty);
         }
 
-        protected override bool ShouldSkipLine(string line) => base.ShouldSkipLine(line) || line.StartsWith(" ") || line.StartsWith("_");
+        protected override bool ShouldSkipLine(string line) => base.ShouldSkipLine(line) || line.StartsWith(" ", StringComparison.Ordinal) || line.StartsWith("_", StringComparison.Ordinal);
 
         protected override void ParseLine(Beatmap beatmap, Section section, string line)
         {

osu.Game/Beatmaps/Formats/LegacyDecoder.cs

@@ -69,7 +69,7 @@ namespace osu.Game.Beatmaps.Formats
 
         protected string StripComments(string line)
         {
-            var index = line.IndexOf("//", StringComparison.Ordinal);
+            var index = line.AsSpan().IndexOf("//".AsSpan());
             if (index > 0)
                 return line.Substring(0, index);
             return line;

osu.Game/Beatmaps/IBeatmap.cs

@@ -39,7 +39,7 @@ namespace osu.Game.Beatmaps
         /// <summary>
         /// The hitobjects contained by this beatmap.
         /// </summary>
-        IEnumerable<HitObject> HitObjects { get; }
+        IReadOnlyList<HitObject> HitObjects { get; }
 
         /// <summary>
         /// Returns statistics for the <see cref="HitObjects"/> contained in this beatmap.

osu.Game/Graphics/UserInterface/OsuDropdown.cs

@@ -30,7 +30,7 @@ namespace osu.Game.Graphics.UserInterface
         [BackgroundDependencyLoader]
         private void load(OsuColour colours)
         {
-            if (accentColour == default(Color4))
+            if (accentColour == default)
                 accentColour = colours.PinkDarker;
             updateAccentColour();
         }

osu.Game/Graphics/UserInterface/OsuTabControl.cs

@@ -53,7 +53,7 @@ namespace osu.Game.Graphics.UserInterface
         [BackgroundDependencyLoader]
         private void load(OsuColour colours)
         {
-            if (accentColour == default(Color4))
+            if (accentColour == default)
                 AccentColour = colours.Blue;
         }
 
@@ -142,7 +142,7 @@ namespace osu.Game.Graphics.UserInterface
             [BackgroundDependencyLoader]
             private void load(OsuColour colours)
             {
-                if (accentColour == default(Color4))
+                if (accentColour == default)
                     AccentColour = colours.Blue;
             }
 

osu.Game/Graphics/UserInterface/RollingCounter.cs

@@ -134,7 +134,7 @@ namespace osu.Game.Graphics.UserInterface
         /// </summary>
         public virtual void ResetCount()
         {
-            SetCountWithoutRolling(default(T));
+            SetCountWithoutRolling(default);
         }
 
         /// <summary>

osu.Game/Rulesets/Objects/BezierApproximator.cs

@@ -1,25 +1,26 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using System.Collections.Generic;
 using OpenTK;
 
 namespace osu.Game.Rulesets.Objects
 {
-    public class BezierApproximator
+    public readonly ref struct BezierApproximator
     {
         private readonly int count;
-        private readonly List<Vector2> controlPoints;
+        private readonly ReadOnlySpan<Vector2> controlPoints;
         private readonly Vector2[] subdivisionBuffer1;
         private readonly Vector2[] subdivisionBuffer2;
 
         private const float tolerance = 0.25f;
         private const float tolerance_sq = tolerance * tolerance;
 
-        public BezierApproximator(List<Vector2> controlPoints)
+        public BezierApproximator(ReadOnlySpan<Vector2> controlPoints)
         {
             this.controlPoints = controlPoints;
-            count = controlPoints.Count;
+            count = controlPoints.Length;
 
             subdivisionBuffer1 = new Vector2[count];
             subdivisionBuffer2 = new Vector2[count * 2 - 1];

osu.Game/Rulesets/Objects/CatmullApproximator.cs

@@ -1,40 +1,40 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using System.Collections.Generic;
 using OpenTK;
 
 namespace osu.Game.Rulesets.Objects
 {
-    public class CatmullApproximator
+    public readonly ref struct CatmullApproximator
     {
         /// <summary>
         /// The amount of pieces to calculate for each controlpoint quadruplet.
         /// </summary>
         private const int detail = 50;
 
-        private readonly List<Vector2> controlPoints;
+        private readonly ReadOnlySpan<Vector2> controlPoints;
 
-        public CatmullApproximator(List<Vector2> controlPoints)
+        public CatmullApproximator(ReadOnlySpan<Vector2> controlPoints)
         {
             this.controlPoints = controlPoints;
         }
 
-
         /// <summary>
         /// Creates a piecewise-linear approximation of a Catmull-Rom spline.
         /// </summary>
         /// <returns>A list of vectors representing the piecewise-linear approximation.</returns>
         public List<Vector2> CreateCatmull()
         {
-            var result = new List<Vector2>();
+            var result = new List<Vector2>((controlPoints.Length - 1) * detail * 2);
 
-            for (int i = 0; i < controlPoints.Count - 1; i++)
+            for (int i = 0; i < controlPoints.Length - 1; i++)
             {
                 var v1 = i > 0 ? controlPoints[i - 1] : controlPoints[i];
                 var v2 = controlPoints[i];
-                var v3 = i < controlPoints.Count - 1 ? controlPoints[i + 1] : v2 + v2 - v1;
-                var v4 = i < controlPoints.Count - 2 ? controlPoints[i + 2] : v3 + v3 - v2;
+                var v3 = i < controlPoints.Length - 1 ? controlPoints[i + 1] : v2 + v2 - v1;
+                var v4 = i < controlPoints.Length - 2 ? controlPoints[i + 2] : v3 + v3 - v2;
 
                 for (int c = 0; c < detail; c++)
                 {

osu.Game/Rulesets/Objects/CircularArcApproximator.cs

@@ -8,21 +8,15 @@ using OpenTK;
 
 namespace osu.Game.Rulesets.Objects
 {
-    public class CircularArcApproximator
+    public readonly ref struct CircularArcApproximator
     {
-        private readonly Vector2 a;
-        private readonly Vector2 b;
-        private readonly Vector2 c;
-
-        private int amountPoints;
-
         private const float tolerance = 0.1f;
 
-        public CircularArcApproximator(Vector2 a, Vector2 b, Vector2 c)
+        private readonly ReadOnlySpan<Vector2> controlPoints;
+
+        public CircularArcApproximator(ReadOnlySpan<Vector2> controlPoints)
         {
-            this.a = a;
-            this.b = b;
-            this.c = c;
+            this.controlPoints = controlPoints;
         }
 
         /// <summary>
@@ -31,6 +25,10 @@ namespace osu.Game.Rulesets.Objects
         /// <returns>A list of vectors representing the piecewise-linear approximation.</returns>
         public List<Vector2> CreateArc()
         {
+            Vector2 a = controlPoints[0];
+            Vector2 b = controlPoints[1];
+            Vector2 c = controlPoints[2];
+
             float aSq = (b - c).LengthSquared;
             float bSq = (a - c).LengthSquared;
             float cSq = (a - b).LengthSquared;
@@ -81,7 +79,7 @@ namespace osu.Game.Rulesets.Objects
             // is: 2 * Math.Acos(1 - TOLERANCE / r)
             // The special case is required for extremely short sliders where the radius is smaller than
             // the tolerance. This is a pathological rather than a realistic case.
-            amountPoints = 2 * r <= tolerance ? 2 : Math.Max(2, (int)Math.Ceiling(thetaRange / (2 * Math.Acos(1 - tolerance / r))));
+            int amountPoints = 2 * r <= tolerance ? 2 : Math.Max(2, (int)Math.Ceiling(thetaRange / (2 * Math.Acos(1 - tolerance / r))));
 
             List<Vector2> output = new List<Vector2>(amountPoints);
 

osu.Game/Rulesets/Objects/Legacy/Catch/ConvertHitObjectParser.cs

@@ -37,7 +37,7 @@ namespace osu.Game.Rulesets.Objects.Legacy.Catch
             };
         }
 
-        protected override HitObject CreateSlider(Vector2 position, bool newCombo, int comboOffset, List<Vector2> controlPoints, double length, CurveType curveType, int repeatCount, List<List<SampleInfo>> repeatSamples)
+        protected override HitObject CreateSlider(Vector2 position, bool newCombo, int comboOffset, Vector2[] controlPoints, double length, CurveType curveType, int repeatCount, List<List<SampleInfo>> repeatSamples)
         {
             newCombo |= forceNewCombo;
             comboOffset += extraComboOffset;

osu.Game/Rulesets/Objects/Legacy/ConvertHitObjectParser.cs

@@ -72,10 +72,18 @@ namespace osu.Game.Rulesets.Objects.Legacy
                 {
                     CurveType curveType = CurveType.Catmull;
                     double length = 0;
-                    var points = new List<Vector2> { Vector2.Zero };
 
-                    string[] pointsplit = split[5].Split('|');
-                    foreach (string t in pointsplit)
+                    string[] pointSplit = split[5].Split('|');
+
+                    int pointCount = 1;
+                    foreach (var t in pointSplit)
+                        if (t.Length > 1)
+                            pointCount++;
+
+                    var points = new Vector2[pointCount];
+
+                    int pointIndex = 1;
+                    foreach (string t in pointSplit)
                     {
                         if (t.Length == 1)
                         {
@@ -94,16 +102,18 @@ namespace osu.Game.Rulesets.Objects.Legacy
                                     curveType = CurveType.PerfectCurve;
                                     break;
                             }
+
                             continue;
                         }
 
                         string[] temp = t.Split(':');
-                        points.Add(new Vector2((int)Convert.ToDouble(temp[0], CultureInfo.InvariantCulture), (int)Convert.ToDouble(temp[1], CultureInfo.InvariantCulture)) - pos);
+                        points[pointIndex++] = new Vector2((int)Convert.ToDouble(temp[0], CultureInfo.InvariantCulture), (int)Convert.ToDouble(temp[1], CultureInfo.InvariantCulture)) - pos;
                     }
 
                     // osu-stable special-cased colinear perfect curves to a CurveType.Linear
-                    bool isLinear(List<Vector2> p) => Precision.AlmostEquals(0, (p[1].Y - p[0].Y) * (p[2].X - p[0].X) - (p[1].X - p[0].X) * (p[2].Y - p[0].Y));
-                    if (points.Count == 3 && curveType == CurveType.PerfectCurve && isLinear(points))
+                    bool isLinear(Vector2[] p) => Precision.AlmostEquals(0, (p[1].Y - p[0].Y) * (p[2].X - p[0].X) - (p[1].X - p[0].X) * (p[2].Y - p[0].Y));
+
+                    if (points.Length == 3 && curveType == CurveType.PerfectCurve && isLinear(points))
                         curveType = CurveType.Linear;
 
                     int repeatCount = Convert.ToInt32(split[6], CultureInfo.InvariantCulture);
@@ -262,7 +272,7 @@ namespace osu.Game.Rulesets.Objects.Legacy
         /// <param name="repeatCount">The slider repeat count.</param>
         /// <param name="repeatSamples">The samples to be played when the repeat nodes are hit. This includes the head and tail of the slider.</param>
         /// <returns>The hit object.</returns>
-        protected abstract HitObject CreateSlider(Vector2 position, bool newCombo, int comboOffset, List<Vector2> controlPoints, double length, CurveType curveType, int repeatCount, List<List<SampleInfo>> repeatSamples);
+        protected abstract HitObject CreateSlider(Vector2 position, bool newCombo, int comboOffset, Vector2[] controlPoints, double length, CurveType curveType, int repeatCount, List<List<SampleInfo>> repeatSamples);
 
         /// <summary>
         /// Creates a legacy Spinner-type hit object.

osu.Game/Rulesets/Objects/Legacy/ConvertSlider.cs

@@ -21,7 +21,7 @@ namespace osu.Game.Rulesets.Objects.Legacy
         /// <see cref="ConvertSlider"/>s don't need a curve since they're converted to ruleset-specific hitobjects.
         /// </summary>
         public SliderCurve Curve { get; } = null;
-        public List<Vector2> ControlPoints { get; set; }
+        public Vector2[] ControlPoints { get; set; }
         public CurveType CurveType { get; set; }
 
         public double Distance { get; set; }

osu.Game/Rulesets/Objects/Legacy/Mania/ConvertHitObjectParser.cs

@@ -26,7 +26,7 @@ namespace osu.Game.Rulesets.Objects.Legacy.Mania
             };
         }
 
-        protected override HitObject CreateSlider(Vector2 position, bool newCombo, int comboOffset, List<Vector2> controlPoints, double length, CurveType curveType, int repeatCount, List<List<SampleInfo>> repeatSamples)
+        protected override HitObject CreateSlider(Vector2 position, bool newCombo, int comboOffset, Vector2[] controlPoints, double length, CurveType curveType, int repeatCount, List<List<SampleInfo>> repeatSamples)
         {
             return new ConvertSlider
             {

osu.Game/Rulesets/Objects/Legacy/Osu/ConvertHitObjectParser.cs

@@ -38,7 +38,7 @@ namespace osu.Game.Rulesets.Objects.Legacy.Osu
             };
         }
 
-        protected override HitObject CreateSlider(Vector2 position, bool newCombo, int comboOffset, List<Vector2> controlPoints, double length, CurveType curveType, int repeatCount, List<List<SampleInfo>> repeatSamples)
+        protected override HitObject CreateSlider(Vector2 position, bool newCombo, int comboOffset, Vector2[] controlPoints, double length, CurveType curveType, int repeatCount, List<List<SampleInfo>> repeatSamples)
         {
             newCombo |= forceNewCombo;
             comboOffset += extraComboOffset;

osu.Game/Rulesets/Objects/Legacy/Taiko/ConvertHitObjectParser.cs

@@ -23,7 +23,7 @@ namespace osu.Game.Rulesets.Objects.Legacy.Taiko
             return new ConvertHit();
         }
 
-        protected override HitObject CreateSlider(Vector2 position, bool newCombo, int comboOffset, List<Vector2> controlPoints, double length, CurveType curveType, int repeatCount, List<List<SampleInfo>> repeatSamples)
+        protected override HitObject CreateSlider(Vector2 position, bool newCombo, int comboOffset, Vector2[] controlPoints, double length, CurveType curveType, int repeatCount, List<List<SampleInfo>> repeatSamples)
         {
             return new ConvertSlider
             {

osu.Game/Rulesets/Objects/SliderCurve.cs

@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using osu.Framework.MathUtils;
@@ -13,7 +14,7 @@ namespace osu.Game.Rulesets.Objects
     {
         public double Distance;
 
-        public List<Vector2> ControlPoints;
+        public Vector2[] ControlPoints;
 
         public CurveType CurveType = CurveType.PerfectCurve;
 
@@ -22,19 +23,23 @@ namespace osu.Game.Rulesets.Objects
         private readonly List<Vector2> calculatedPath = new List<Vector2>();
         private readonly List<double> cumulativeLength = new List<double>();
 
-        private List<Vector2> calculateSubpath(List<Vector2> subControlPoints)
+        private List<Vector2> calculateSubpath(ReadOnlySpan<Vector2> subControlPoints)
         {
             switch (CurveType)
             {
                 case CurveType.Linear:
-                    return subControlPoints;
+                    var result = new List<Vector2>(subControlPoints.Length);
+                    foreach (var c in subControlPoints)
+                        result.Add(c);
+
+                    return result;
                 case CurveType.PerfectCurve:
                     //we can only use CircularArc iff we have exactly three control points and no dissection.
-                    if (ControlPoints.Count != 3 || subControlPoints.Count != 3)
+                    if (ControlPoints.Length != 3 || subControlPoints.Length != 3)
                         break;
 
                     // Here we have exactly 3 control points. Attempt to fit a circular arc.
-                    List<Vector2> subpath = new CircularArcApproximator(subControlPoints[0], subControlPoints[1], subControlPoints[2]).CreateArc();
+                    List<Vector2> subpath = new CircularArcApproximator(subControlPoints).CreateArc();
 
                     // If for some reason a circular arc could not be fit to the 3 given points, fall back to a numerically stable bezier approximation.
                     if (subpath.Count == 0)
@@ -55,18 +60,23 @@ namespace osu.Game.Rulesets.Objects
             // Sliders may consist of various subpaths separated by two consecutive vertices
             // with the same position. The following loop parses these subpaths and computes
             // their shape independently, consecutively appending them to calculatedPath.
-            List<Vector2> subControlPoints = new List<Vector2>();
-            for (int i = 0; i < ControlPoints.Count; ++i)
+
+            int start = 0;
+            int end = 0;
+
+            for (int i = 0; i < ControlPoints.Length; ++i)
             {
-                subControlPoints.Add(ControlPoints[i]);
-                if (i == ControlPoints.Count - 1 || ControlPoints[i] == ControlPoints[i + 1])
+                end++;
+
+                if (i == ControlPoints.Length - 1 || ControlPoints[i] == ControlPoints[i + 1])
                 {
-                    List<Vector2> subpath = calculateSubpath(subControlPoints);
-                    foreach (Vector2 t in subpath)
+                    ReadOnlySpan<Vector2> cpSpan = ControlPoints.AsSpan().Slice(start, end - start);
+
+                    foreach (Vector2 t in calculateSubpath(cpSpan))
                         if (calculatedPath.Count == 0 || calculatedPath.Last() != t)
                             calculatedPath.Add(t);
 
-                    subControlPoints.Clear();
+                    start = end;
                 }
             }
         }
@@ -166,7 +176,7 @@ namespace osu.Game.Rulesets.Objects
         /// <param name="p1">End progress. Ranges from 0 (beginning of the slider) to 1 (end of the slider).</param>
         public void GetPathToProgress(List<Vector2> path, double p0, double p1)
         {
-            if (calculatedPath.Count == 0 && ControlPoints.Count > 0)
+            if (calculatedPath.Count == 0 && ControlPoints.Length > 0)
                 Calculate();
 
             double d0 = progressToDistance(p0);
@@ -193,7 +203,7 @@ namespace osu.Game.Rulesets.Objects
         /// <returns></returns>
         public Vector2 PositionAt(double progress)
         {
-            if (calculatedPath.Count == 0 && ControlPoints.Count > 0)
+            if (calculatedPath.Count == 0 && ControlPoints.Length > 0)
                 Calculate();
 
             double d = progressToDistance(progress);

osu.Game/Rulesets/Objects/Types/IHasCurve.cs

@@ -1,7 +1,6 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
-using System.Collections.Generic;
 using OpenTK;
 
 namespace osu.Game.Rulesets.Objects.Types
@@ -19,7 +18,7 @@ namespace osu.Game.Rulesets.Objects.Types
         /// <summary>
         /// The control points that shape the curve.
         /// </summary>
-        List<Vector2> ControlPoints { get; }
+        Vector2[] ControlPoints { get; }
 
         /// <summary>
         /// The type of curve.

osu.Game/Storyboards/CommandTimeline.cs

@@ -21,8 +21,8 @@ namespace osu.Game.Storyboards
         private Cached<double> endTimeBacking;
         public double EndTime => endTimeBacking.IsValid ? endTimeBacking : endTimeBacking.Value = HasCommands ? commands.Max(c => c.EndTime) : double.MaxValue;
 
-        public T StartValue => HasCommands ? commands.OrderBy(c => c.StartTime).First().StartValue : default(T);
-        public T EndValue => HasCommands ? commands.OrderByDescending(c => c.EndTime).First().EndValue : default(T);
+        public T StartValue => HasCommands ? commands.OrderBy(c => c.StartTime).First().StartValue : default;
+        public T EndValue => HasCommands ? commands.OrderByDescending(c => c.EndTime).First().EndValue : default;
 
         public void Add(Easing easing, double startTime, double endTime, T startValue, T endValue)
         {