Rewrite mania to use the new timing section stuff.

osu.Desktop.VisualTests/Tests/TestCaseManiaPlayfield.cs

@@ -13,8 +13,9 @@ using osu.Framework.Configuration;
 using OpenTK.Input;
 using osu.Framework.Timing;
 using osu.Framework.Extensions.IEnumerableExtensions;
-using osu.Game.Rulesets.Mania.Timing.Drawables;
 using System.Linq;
+using osu.Game.Rulesets.Mania.Timing;
+using osu.Game.Rulesets.Mania.Timing.Drawables;
 using osu.Game.Rulesets.Timing;
 using osu.Game.Rulesets.Timing.Drawables;
 
@@ -45,23 +46,11 @@ namespace osu.Desktop.VisualTests.Tests
             const double start_time = 500;
             const double duration = 500;
 
-            Func<double, bool, DrawableTimingSection> createTimingChange = (time, gravity) =>
+            Func<double, bool, DrawableTimingSection> createTimingChange = (time, gravity) => new DrawableManiaTimingSection(new TimingSection
             {
-                if (gravity)
+                BeatLength = 1000,
-                {
+                Time = time
-                    return new DrawableManiaGravityTimingChange(new TimingSection
+            }, gravity ? ScrollingAlgorithm.Gravity : ScrollingAlgorithm.Basic);
-                    {
-                        BeatLength = 1000,
-                        Time = time
-                    });
-                }
-
-                return new DrawableManiaScrollingTimingChange(new TimingSection
-                {
-                    BeatLength = 1000,
-                    Time = time
-                });
-            };
 
             Action<bool> createPlayfieldWithNotes = gravity =>
             {

osu.Game.Rulesets.Mania/Mods/ManiaModGravity.cs

@@ -6,13 +6,14 @@ using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mania.UI;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.UI;
-using osu.Game.Rulesets.Mania.Timing.Drawables;
 using osu.Game.Rulesets.Objects.Types;
 using System.Linq;
 using osu.Framework.Lists;
 using osu.Game.Beatmaps.ControlPoints;
 using osu.Framework.MathUtils;
 using osu.Game.Graphics;
+using osu.Game.Rulesets.Mania.Timing;
+using osu.Game.Rulesets.Mania.Timing.Drawables;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Timing;
 using osu.Game.Rulesets.Timing.Drawables;
@@ -43,11 +44,11 @@ namespace osu.Game.Rulesets.Mania.Mods
                 if (maniaObject == null)
                     continue;
 
-                maniaHitRenderer.HitObjectTimingChanges[maniaObject.Column].Add(new DrawableManiaGravityTimingChange(new TimingSection
+                maniaHitRenderer.HitObjectTimingChanges[maniaObject.Column].Add(new DrawableManiaTimingSection(new TimingSection
                 {
                     Time = obj.StartTime,
                     BeatLength = 1000
-                }));
+                }, ScrollingAlgorithm.Gravity));
             }
 
             double lastObjectTime = (maniaHitRenderer.Objects.LastOrDefault() as IHasEndTime)?.EndTime ?? maniaHitRenderer.Objects.LastOrDefault()?.StartTime ?? double.MaxValue;
@@ -62,11 +63,11 @@ namespace osu.Game.Rulesets.Mania.Mods
 
                 for (double t = timingPoints[i].Time; Precision.DefinitelyBigger(endTime, t); t += point.BeatLength)
                 {
-                    maniaHitRenderer.BarlineTimingChanges.Add(new DrawableManiaGravityTimingChange(new TimingSection
+                    maniaHitRenderer.BarlineTimingChanges.Add(new DrawableManiaTimingSection(new TimingSection
                     {
                         Time = t,
                         BeatLength = 1000
-                    }));
+                    }, ScrollingAlgorithm.Gravity));
                 }
             }
         }

osu.Game.Rulesets.Mania/Timing/Drawables/BasicScrollingHitObjectCollection.cs

@@ -0,0 +1,27 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using osu.Framework.Graphics;
+using osu.Game.Rulesets.Timing;
+using osu.Game.Rulesets.Timing.Drawables;
+
+namespace osu.Game.Rulesets.Mania.Timing.Drawables
+{
+    internal class BasicScrollingHitObjectCollection : HitObjectCollection
+    {
+        private readonly TimingSection timingSection;
+
+        public BasicScrollingHitObjectCollection(TimingSection timingSection)
+            : base(Axes.Y)
+        {
+            this.timingSection = timingSection;
+        }
+
+        protected override void Update()
+        {
+            base.Update();
+
+            Y = (float)(timingSection.Time - Time.Current);
+        }
+    }
+}

osu.Game.Rulesets.Mania/Timing/Drawables/DrawableManiaScrollingTimingChange.cs

@@ -1,25 +0,0 @@
-// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
-// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
-
-using osu.Game.Rulesets.Timing;
-
-namespace osu.Game.Rulesets.Mania.Timing.Drawables
-{
-    /// <summary>
-    /// A basic timing change which scrolls along with a timing change.
-    /// </summary>
-    public class DrawableManiaScrollingTimingChange : DrawableManiaTimingChange
-    {
-        public DrawableManiaScrollingTimingChange(TimingSection timingChange)
-            : base(timingChange)
-        {
-        }
-
-        protected override void Update()
-        {
-            base.Update();
-
-            Content.Y = (float)(TimingChange.Time - Time.Current);
-        }
-    }
-}

osu.Game.Rulesets.Mania/Timing/Drawables/DrawableManiaTimingChange.cs

@@ -1,31 +0,0 @@
-// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
-// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
-
-using osu.Framework.Graphics;
-using osu.Game.Rulesets.Timing;
-using osu.Game.Rulesets.Timing.Drawables;
-
-namespace osu.Game.Rulesets.Mania.Timing.Drawables
-{
-    public abstract class DrawableManiaTimingChange : DrawableTimingSection
-    {
-        protected DrawableManiaTimingChange(TimingSection timingChange)
-            : base(timingChange, Axes.Y)
-        {
-        }
-
-        protected override void UpdateAfterChildren()
-        {
-            base.UpdateAfterChildren();
-
-            var parent = Parent as TimingSectionCollection;
-
-            if (parent == null)
-                return;
-
-            // This is very naive and can be improved, but is adequate for now
-            LifetimeStart = TimingChange.Time - parent.TimeSpan;
-            LifetimeEnd = TimingChange.Time + Content.RelativeChildSize.Y * 2;
-        }
-    }
-}

osu.Game.Rulesets.Mania/Timing/Drawables/DrawableManiaTimingSection.cs

@@ -0,0 +1,46 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using osu.Framework.Graphics;
+using osu.Game.Rulesets.Timing;
+using osu.Game.Rulesets.Timing.Drawables;
+
+namespace osu.Game.Rulesets.Mania.Timing.Drawables
+{
+    public class DrawableManiaTimingSection : DrawableTimingSection
+    {
+        private readonly ScrollingAlgorithm scrollingAlgorithm;
+
+        public DrawableManiaTimingSection(TimingSection timingSection, ScrollingAlgorithm scrollingAlgorithm)
+            : base(timingSection, Axes.Y)
+        {
+            this.scrollingAlgorithm = scrollingAlgorithm;
+        }
+
+        protected override void UpdateAfterChildren()
+        {
+            base.UpdateAfterChildren();
+
+            var parent = Parent as TimingSectionCollection;
+
+            if (parent == null)
+                return;
+
+            // This is very naive and can be improved, but is adequate for now
+            LifetimeStart = TimingSection.Time - parent.TimeSpan;
+            LifetimeEnd = TimingSection.Time + Content.Height * 2;
+        }
+
+        protected override HitObjectCollection CreateHitObjectCollection()
+        {
+            switch (scrollingAlgorithm)
+            {
+                default:
+                case ScrollingAlgorithm.Basic:
+                    return new BasicScrollingHitObjectCollection(TimingSection);
+                case ScrollingAlgorithm.Gravity:
+                    return new GravityScrollingHitObjectCollection(TimingSection, () => RelativeChildSize.Y);
+            }
+        }
+    }
+}

osu.Game.Rulesets.Mania/Timing/Drawables/GravityScrollingHitObjectCollection.cs

@@ -1,31 +1,36 @@
-// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
+using osu.Framework.Graphics;
 using osu.Game.Rulesets.Timing;
+using osu.Game.Rulesets.Timing.Drawables;
 
 namespace osu.Game.Rulesets.Mania.Timing.Drawables
 {
-    /// <summary>
+    internal class GravityScrollingHitObjectCollection : HitObjectCollection
-    /// A timing change which scrolls with an increasing velocity, following a form of "gravity".
-    /// </summary>
-    public class DrawableManiaGravityTimingChange : DrawableManiaTimingChange
     {
-        public DrawableManiaGravityTimingChange(TimingSection timingChange)
+        private readonly TimingSection timingSection;
-            : base(timingChange)
+        private readonly Func<double> timeSpan;
+
+        public GravityScrollingHitObjectCollection(TimingSection timingSection, Func<double> timeSpan)
+            : base(Axes.Y)
         {
+            this.timingSection = timingSection;
+            this.timeSpan = timeSpan;
         }
 
-        protected override void Update()
+        protected override void UpdateAfterChildren()
         {
-            base.Update();
+            base.UpdateAfterChildren();
 
             // The gravity-adjusted start position
-            float startY = (float)computeGravityTime(TimingChange.Time);
+            float startPos = (float)computeGravityTime(timingSection.Time);
             // The gravity-adjusted end position
-            float endY = (float)computeGravityTime(TimingChange.Time + Content.RelativeChildSize.Y);
+            float endPos = (float)computeGravityTime(timingSection.Time + RelativeChildSize.Y);
 
-            Content.Y = startY;
+            Y = startPos;
-            Content.Height = endY - startY;
+            Height = endPos - startPos;
         }
 
         /// <summary>
@@ -40,24 +45,19 @@ namespace osu.Game.Rulesets.Mania.Timing.Drawables
             // The sign of the relative time, this is used to apply backwards acceleration leading into startTime
             double sign = relativeTime < 0 ? -1 : 1;
 
-            return timeSpan - acceleration * relativeTime * relativeTime * sign;
+            return timeSpan() - acceleration * relativeTime * relativeTime * sign;
         }
 
-        /// <summary>
-        /// The time spanned by this container.
-        /// </summary>
-        private double timeSpan => RelativeChildSize.Y;
-
         /// <summary>
         /// The acceleration due to "gravity" of the content of this container.
         /// </summary>
-        private double acceleration => 1 / timeSpan;
+        private double acceleration => 1 / timeSpan();
 
         /// <summary>
         /// Computes the current time relative to <paramref name="time"/>, accounting for <see cref="timeSpan"/>.
         /// </summary>
         /// <param name="time">The non-offset time.</param>
         /// <returns>The current time relative to <paramref name="time"/> - <see cref="timeSpan"/>. </returns>
-        private double relativeTimeAt(double time) => Time.Current - time + timeSpan;
+        private double relativeTimeAt(double time) => Time.Current - time + timeSpan();
     }
-}
+}

osu.Game.Rulesets.Mania/Timing/ScrollingAlgorithm.cs

@@ -0,0 +1,17 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+namespace osu.Game.Rulesets.Mania.Timing
+{
+    public enum ScrollingAlgorithm
+    {
+        /// <summary>
+        /// Basic scrolling algorithm based on the timing section time. This is the default algorithm.
+        /// </summary>
+        Basic,
+        /// <summary>
+        /// Emulating a form of gravity where hit objects speed up over time.
+        /// </summary>
+        Gravity
+    }
+}

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

@@ -20,6 +20,7 @@ using osu.Game.Rulesets.Mania.Judgements;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Mania.Objects.Drawables;
 using osu.Game.Rulesets.Mania.Scoring;
+using osu.Game.Rulesets.Mania.Timing;
 using osu.Game.Rulesets.Mania.Timing.Drawables;
 using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.Objects.Types;
@@ -114,9 +115,9 @@ namespace osu.Game.Rulesets.Mania.UI
             timingChanges.ForEach(t =>
             {
                 for (int i = 0; i < PreferredColumns; i++)
-                    HitObjectTimingChanges[i].Add(new DrawableManiaScrollingTimingChange(t));
+                    HitObjectTimingChanges[i].Add(new DrawableManiaTimingSection(t, ScrollingAlgorithm.Basic));
 
-                BarlineTimingChanges.Add(new DrawableManiaScrollingTimingChange(t));
+                BarlineTimingChanges.Add(new DrawableManiaTimingSection(t, ScrollingAlgorithm.Basic));
             });
         }
 

osu.Game.Rulesets.Mania/osu.Game.Rulesets.Mania.csproj

@@ -77,6 +77,9 @@
     <Compile Include="Objects\ManiaHitObject.cs" />
     <Compile Include="Objects\Note.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Timing\Drawables\BasicScrollingHitObjectCollection.cs" />
+    <Compile Include="Timing\Drawables\GravityScrollingHitObjectCollection.cs" />
+    <Compile Include="Timing\ScrollingAlgorithm.cs" />
     <Compile Include="UI\Column.cs" />
     <Compile Include="UI\ManiaHitRenderer.cs" />
     <Compile Include="UI\ManiaPlayfield.cs" />
@@ -84,9 +87,7 @@
     <Compile Include="Mods\ManiaMod.cs" />
     <Compile Include="Mods\ManiaModGravity.cs" />
     <Compile Include="UI\SpecialColumnPosition.cs" />
-    <Compile Include="Timing\Drawables\DrawableManiaGravityTimingChange.cs" />
+    <Compile Include="Timing\Drawables\DrawableManiaTimingSection.cs" />
-    <Compile Include="Timing\Drawables\DrawableManiaTimingChange.cs" />
-    <Compile Include="Timing\Drawables\DrawableManiaScrollingTimingChange.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\osu-framework\osu.Framework\osu.Framework.csproj">