Rework/rewrite beatmap parsing to parse to base hit objects, which mode-specific beatmap converters can then use.

osu.Desktop.VisualTests/Tests/TestCaseHitObjects.cs

@@ -75,7 +75,7 @@ namespace osu.Desktop.VisualTests.Tests
                     add(new DrawableSpinner(new Spinner
                     {
                         StartTime = framedClock.CurrentTime + 600,
-                        Length = 1000,
+                        EndTime = framedClock.CurrentTime + 1600,
                         Position = new Vector2(0, 0),
                     }));
                     break;

osu.Game.Modes.Catch/Beatmaps/CatchBeatmapConverter.cs

@@ -10,7 +10,7 @@ namespace osu.Game.Modes.Catch.Beatmaps
 {
     internal class CatchBeatmapConverter : IBeatmapConverter<CatchBaseHit>
     {
-        public Beatmap<CatchBaseHit> Convert(Beatmap original)
+        public Beatmap<CatchBaseHit> ConvertBeatmap(Beatmap original)
         {
             return new Beatmap<CatchBaseHit>(original)
             {

osu.Game.Modes.Catch/CatchRuleset.cs

@@ -5,7 +5,6 @@ using OpenTK.Input;
 using osu.Game.Beatmaps;
 using osu.Game.Graphics;
 using osu.Game.Modes.Catch.UI;
-using osu.Game.Modes.Objects;
 using osu.Game.Modes.UI;
 using osu.Game.Screens.Play;
 using System.Collections.Generic;
@@ -88,8 +87,6 @@ namespace osu.Game.Modes.Catch
 
         public override ScoreProcessor CreateScoreProcessor(int hitObjectCount = 0) => null;
 
-        public override HitObjectParser CreateHitObjectParser() => new NullHitObjectParser();
-
         public override DifficultyCalculator CreateDifficultyCalculator(Beatmap beatmap) => new CatchDifficultyCalculator(beatmap);
     }
 }

osu.Game.Modes.Catch/Objects/CatchBaseHit.cs

@@ -1,12 +1,14 @@
-// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+using OpenTK;
+// 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.Modes.Objects;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Modes.Catch.Objects
 {
-    public abstract class CatchBaseHit : HitObject
+    public abstract class CatchBaseHit : HitObject, IHasPosition
     {
-        public float Position;
+        public Vector2 Position { get; set; }
     }
 }

osu.Game.Modes.Catch/Objects/CatchConverter.cs

@@ -1,40 +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 System.Collections.Generic;
-using osu.Game.Modes.Objects;
-using osu.Game.Modes.Osu.Objects;
-using osu.Game.Beatmaps;
-
-namespace osu.Game.Modes.Catch.Objects
-{
-    internal class CatchConverter : HitObjectConverter<CatchBaseHit>
-    {
-        public override List<CatchBaseHit> Convert(Beatmap beatmap)
-        {
-            List<CatchBaseHit> output = new List<CatchBaseHit>();
-
-            foreach (HitObject i in beatmap.HitObjects)
-            {
-                CatchBaseHit h = i as CatchBaseHit;
-
-                if (h == null)
-                {
-                    OsuHitObject o = i as OsuHitObject;
-
-                    if (o == null) throw new HitObjectConvertException(@"Catch", i);
-
-                    h = new Fruit
-                    {
-                        StartTime = o.StartTime,
-                        Position = o.Position.X,
-                    };
-                }
-
-                output.Add(h);
-            }
-
-            return output;
-        }
-    }
-}

osu.Game.Modes.Catch/Objects/Drawable/DrawableFruit.cs

@@ -7,6 +7,7 @@ using osu.Framework.Graphics.Sprites;
 using osu.Framework.Graphics.Textures;
 using osu.Framework.Graphics.Transforms;
 using OpenTK;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Modes.Catch.Objects.Drawable
 {
@@ -21,7 +22,7 @@ namespace osu.Game.Modes.Catch.Objects.Drawable
             Origin = Anchor.Centre;
             Scale = new Vector2(0.1f);
             RelativePositionAxes = Axes.Y;
-            Position = new Vector2(h.Position, -0.1f);
+            Position = new Vector2(h.Position.X, -0.1f);
         }
 
         [BackgroundDependencyLoader]
@@ -29,8 +30,11 @@ namespace osu.Game.Modes.Catch.Objects.Drawable
         {
             Texture = textures.Get(@"Menu/logo");
 
-            Transforms.Add(new TransformPosition { StartTime = h.StartTime - 200, EndTime = h.StartTime, StartValue = new Vector2(h.Position, -0.1f), EndValue = new Vector2(h.Position, 0.9f) });
+            double endTime = (h as IHasEndTime)?.EndTime ?? h.StartTime;
-            Transforms.Add(new TransformAlpha { StartTime = h.StartTime + h.Duration + 200, EndTime = h.StartTime + h.Duration + 400, StartValue = 1, EndValue = 0 });
+            double duration = endTime - h.StartTime;
+
+            Transforms.Add(new TransformPosition { StartTime = h.StartTime - 200, EndTime = h.StartTime, StartValue = new Vector2(h.Position.X, -0.1f), EndValue = new Vector2(h.Position.X, 0.9f) });
+            Transforms.Add(new TransformAlpha { StartTime = h.StartTime + duration + 200, EndTime = h.StartTime + duration + 400, StartValue = 1, EndValue = 0 });
             Expire(true);
         }
     }

osu.Game.Modes.Catch/osu.Game.Modes.Catch.csproj

@@ -50,7 +50,6 @@
     <Compile Include="Beatmaps\CatchBeatmapConverter.cs" />
     <Compile Include="CatchDifficultyCalculator.cs" />
     <Compile Include="Objects\CatchBaseHit.cs" />
-    <Compile Include="Objects\CatchConverter.cs" />
     <Compile Include="Objects\Drawable\DrawableFruit.cs" />
     <Compile Include="Objects\Droplet.cs" />
     <Compile Include="Objects\Fruit.cs" />

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

@@ -10,7 +10,7 @@ namespace osu.Game.Modes.Mania.Beatmaps
 {
     internal class ManiaBeatmapConverter : IBeatmapConverter<ManiaBaseHit>
     {
-        public Beatmap<ManiaBaseHit> Convert(Beatmap original)
+        public Beatmap<ManiaBaseHit> ConvertBeatmap(Beatmap original)
         {
             return new Beatmap<ManiaBaseHit>(original)
             {

osu.Game.Modes.Mania/ManiaRuleset.cs

@@ -4,7 +4,6 @@
 using osu.Game.Beatmaps;
 using osu.Game.Graphics;
 using osu.Game.Modes.Mania.UI;
-using osu.Game.Modes.Objects;
 using osu.Game.Modes.UI;
 using osu.Game.Screens.Play;
 using System.Collections.Generic;
@@ -103,8 +102,6 @@ namespace osu.Game.Modes.Mania
 
         public override ScoreProcessor CreateScoreProcessor(int hitObjectCount = 0) => null;
 
-        public override HitObjectParser CreateHitObjectParser() => new NullHitObjectParser();
-
         public override DifficultyCalculator CreateDifficultyCalculator(Beatmap beatmap) => new ManiaDifficultyCalculator(beatmap);
     }
 }

osu.Game.Modes.Mania/Objects/ManiaBaseHit.cs

@@ -2,11 +2,16 @@
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
 using osu.Game.Modes.Objects;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Modes.Mania.Objects
 {
-    public abstract class ManiaBaseHit : HitObject
+    public abstract class ManiaBaseHit : HitObject, IHasEndTime
     {
         public int Column;
+
+        public double EndTime { get; set; }
+
+        public double Duration { get; set; }
     }
 }

osu.Game.Modes.Mania/Objects/ManiaConverter.cs

@@ -1,48 +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 System;
-using System.Collections.Generic;
-using osu.Game.Modes.Objects;
-using osu.Game.Modes.Osu.Objects;
-using osu.Game.Beatmaps;
-
-namespace osu.Game.Modes.Mania.Objects
-{
-    internal class ManiaConverter : HitObjectConverter<ManiaBaseHit>
-    {
-        private readonly int columns;
-
-        public ManiaConverter(int columns)
-        {
-            this.columns = columns;
-        }
-
-        public override List<ManiaBaseHit> Convert(Beatmap beatmap)
-        {
-            List<ManiaBaseHit> output = new List<ManiaBaseHit>();
-
-            foreach (HitObject i in beatmap.HitObjects)
-            {
-                ManiaBaseHit h = i as ManiaBaseHit;
-
-                if (h == null)
-                {
-                    OsuHitObject o = i as OsuHitObject;
-
-                    if (o == null) throw new HitObjectConvertException(@"Mania", i);
-
-                    h = new Note
-                    {
-                        StartTime = o.StartTime,
-                        Column = (int)Math.Round(o.Position.X / 512 * columns)
-                    };
-                }
-
-                output.Add(h);
-            }
-
-            return output;
-        }
-    }
-}

osu.Game.Modes.Mania/osu.Game.Modes.Mania.csproj

@@ -52,7 +52,6 @@
     <Compile Include="Objects\Drawable\DrawableNote.cs" />
     <Compile Include="Objects\HoldNote.cs" />
     <Compile Include="Objects\ManiaBaseHit.cs" />
-    <Compile Include="Objects\ManiaConverter.cs" />
     <Compile Include="Objects\Note.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="UI\ManiaHitRenderer.cs" />

osu.Game.Modes.Osu/Beatmaps/OsuBeatmapConverter.cs

@@ -8,29 +8,90 @@ using osu.Game.Modes.Objects;
 using osu.Game.Modes.Osu.Objects;
 using osu.Game.Modes.Osu.Objects.Drawables;
 using System.Collections.Generic;
+using osu.Game.Modes.Objects.Types;
+using OpenTK.Graphics;
 
 namespace osu.Game.Modes.Osu.Beatmaps
 {
     internal class OsuBeatmapConverter : IBeatmapConverter<OsuHitObject>
     {
-        public Beatmap<OsuHitObject> Convert(Beatmap original)
+        public Beatmap<OsuHitObject> ConvertBeatmap(Beatmap original)
         {
             return new Beatmap<OsuHitObject>(original)
             {
-                HitObjects = convertHitObject(original.HitObjects, original.BeatmapInfo?.StackLeniency ?? 0.7f)
+                HitObjects = convertHitObjects(original.HitObjects, original.BeatmapInfo?.StackLeniency ?? 0.7f)
             };
         }
 
-        private List<OsuHitObject> convertHitObject(List<HitObject> hitObjects, float stackLeniency)
+        private OsuHitObject convertHitObject(HitObject original)
+        {
+            IHasCurve ihc = original as IHasCurve;
+            IHasDistance ihd = original as IHasDistance;
+            IHasEndTime ihet = original as IHasEndTime;
+            IHasPosition ihp = original as IHasPosition;
+            IHasRepeats ihr = original as IHasRepeats;
+            IHasCombo ihco = original as IHasCombo;
+
+            if (ihc != null)
+            {
+                return new Slider
+                {
+                    StartTime = original.StartTime,
+                    Sample = original.Sample,
+
+                    CurveType = ihc.CurveType,
+                    ControlPoints = ihc.ControlPoints,
+
+                    Position = ihp?.Position ?? Vector2.Zero,
+                    ComboColour = ihco?.ComboColour ?? Color4.White,
+                    ComboIndex = ihco?.ComboIndex ?? 0,
+                    NewCombo = ihco?.NewCombo ?? false,
+                    Length = ihd?.Distance ?? 0,
+                    RepeatCount = ihr?.RepeatCount ?? 0
+                };
+            }
+
+            if (ihet != null)
+            {
+                return new Spinner
+                {
+                    StartTime = original.StartTime,
+                    Sample = original.Sample,
+                    Position = new Vector2(512, 384) / 2,
+
+                    EndTime = ihet.EndTime,
+
+                    ComboColour = ihco?.ComboColour ?? Color4.White,
+                    ComboIndex = ihco?.ComboIndex ?? 0,
+                    NewCombo = ihco?.NewCombo ?? false,
+                };
+            }
+
+            return new HitCircle
+            {
+                StartTime = original.StartTime,
+                Sample = original.Sample,
+
+                Position = ihp?.Position ?? Vector2.Zero,
+                ComboColour = ihco?.ComboColour ?? Color4.White,
+                ComboIndex = ihco?.ComboIndex ?? 0,
+                NewCombo = ihco?.NewCombo ?? false
+            };
+        }
+
+        private List<OsuHitObject> convertHitObjects(List<HitObject> hitObjects, float stackLeniency)
         {
             List<OsuHitObject> converted = new List<OsuHitObject>();
 
             int combo = 0;
             foreach (HitObject h in hitObjects)
             {
-                if (h.NewCombo) combo = 0;
+                OsuHitObject c = convertHitObject(h);
 
-                h.ComboIndex = combo++;
+                if (c.NewCombo)
+                    combo = 0;
+
+                c.ComboIndex = combo++;
                 converted.Add(h as OsuHitObject);
             }
 
@@ -62,9 +123,12 @@ namespace osu.Game.Modes.Osu.Beatmaps
                     if (stackBaseObject is Spinner) break;
 
                     OsuHitObject objectN = hitObjects[n];
-                    if (objectN is Spinner) continue;
+                    if (objectN is Spinner)
+                        continue;
 
-                    if (objectN.StartTime - stackBaseObject.EndTime > stackThreshold)
+                    double endTime = (stackBaseObject as IHasEndTime)?.EndTime ?? stackBaseObject.StartTime;
+
+                    if (objectN.StartTime - endTime > stackThreshold)
                         //We are no longer within stacking range of the next object.
                         break;
 
@@ -116,7 +180,9 @@ namespace osu.Game.Modes.Osu.Beatmaps
                         OsuHitObject objectN = hitObjects[n];
                         if (objectN is Spinner) continue;
 
-                        if (objectI.StartTime - objectN.EndTime > stackThreshold)
+                        double endTime = (objectN as IHasEndTime)?.EndTime ?? objectN.StartTime;
+
+                        if (objectI.StartTime - endTime > stackThreshold)
                             //We are no longer within stacking range of the previous object.
                             break;
 

osu.Game.Modes.Osu/Objects/Drawables/Connections/FollowPointRenderer.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using OpenTK;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Modes.Osu.Objects.Drawables.Connections
 {
@@ -63,7 +64,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables.Connections
                 {
                     Vector2 startPosition = prevHitObject.EndPosition;
                     Vector2 endPosition = currHitObject.Position;
-                    double startTime = prevHitObject.EndTime;
+                    double startTime = (prevHitObject as IHasEndTime)?.EndTime ?? prevHitObject.StartTime;
                     double endTime = currHitObject.StartTime;
 
                     Vector2 distanceVector = endPosition - startPosition;

osu.Game.Modes.Osu/Objects/Drawables/DrawableHitCircle.cs

@@ -7,6 +7,7 @@ using osu.Framework.Graphics.Transforms;
 using osu.Game.Modes.Objects.Drawables;
 using osu.Game.Modes.Osu.Objects.Drawables.Pieces;
 using OpenTK;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Modes.Osu.Objects.Drawables
 {
@@ -35,11 +36,11 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
             {
                 glow = new GlowPiece
                 {
-                    Colour = osuObject.Colour
+                    Colour = osuObject.ComboColour
                 },
                 circle = new CirclePiece
                 {
-                    Colour = osuObject.Colour,
+                    Colour = osuObject.ComboColour,
                     Hit = () =>
                     {
                         if (Judgement.Result.HasValue) return false;
@@ -57,11 +58,11 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
                 flash = new FlashPiece(),
                 explode = new ExplodePiece
                 {
-                    Colour = osuObject.Colour,
+                    Colour = osuObject.ComboColour,
                 },
                 ApproachCircle = new ApproachCircle
                 {
-                    Colour = osuObject.Colour,
+                    Colour = osuObject.ComboColour,
                 }
             };
 
@@ -118,13 +119,16 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
 
             ApproachCircle.FadeOut();
 
-            glow.Delay(osuObject.Duration);
+            double endTime = (osuObject as IHasEndTime)?.EndTime ?? osuObject.StartTime;
+            double duration = endTime - osuObject.StartTime;
+
+            glow.Delay(duration);
             glow.FadeOut(400);
 
             switch (state)
             {
                 case ArmedState.Idle:
-                    Delay(osuObject.Duration + TIME_PREEMPT);
+                    Delay(duration + TIME_PREEMPT);
                     FadeOut(TIME_FADEOUT);
                     break;
                 case ArmedState.Miss:

osu.Game.Modes.Osu/Objects/Drawables/DrawableSlider.cs

@@ -60,7 +60,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
                     Position = s.StackedPosition,
                     ComboIndex = s.ComboIndex,
                     Scale = s.Scale,
-                    Colour = s.Colour,
+                    ComboColour = s.ComboColour,
                     Sample = s.Sample,
                 }),
             };
@@ -128,7 +128,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
             var j = (OsuJudgementInfo)Judgement;
             var sc = (OsuJudgementInfo)initialCircle.Judgement;
 
-            if (!userTriggered && Time.Current >= HitObject.EndTime)
+            if (!userTriggered && Time.Current >= slider.EndTime)
             {
                 var ticksCount = ticks.Children.Count() + 1;
                 var ticksHit = ticks.Children.Count(t => t.Judgement.Result == HitResult.Hit);
@@ -165,7 +165,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
 
             ball.FadeIn();
 
-            Delay(HitObject.Duration, true);
+            Delay(slider.Duration, true);
 
             body.FadeOut(160);
             ball.FadeOut(160);

osu.Game.Modes.Osu/Objects/Drawables/DrawableSliderTick.cs

@@ -47,7 +47,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
                 new Box
                 {
                     RelativeSizeAxes = Axes.Both,
-                    Colour = sliderTick.Colour,
+                    Colour = sliderTick.ComboColour,
                     Alpha = 0.3f,
                 }
             };

osu.Game.Modes.Osu/Objects/Drawables/DrawableSpinner.cs

@@ -46,7 +46,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
                     Alpha = 0,
                     Anchor = Anchor.Centre,
                     Origin = Anchor.Centre,
-                    DiscColour = s.Colour
+                    DiscColour = s.ComboColour
                 },
                 circleContainer = new Container
                 {
@@ -82,7 +82,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
             if (Progress >= 1)
                 disc.Complete = true;
 
-            if (!userTriggered && Time.Current >= HitObject.EndTime)
+            if (!userTriggered && Time.Current >= spinner.EndTime)
             {
                 if (Progress >= 1)
                 {
@@ -102,7 +102,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
                 else
                 {
                     j.Score = OsuScoreResult.Miss;
-                    if (Time.Current >= HitObject.EndTime)
+                    if (Time.Current >= spinner.EndTime)
                         j.Result = HitResult.Miss;
                 }
             }
@@ -140,7 +140,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables
 
             base.UpdateState(state);
 
-            Delay(HitObject.Duration, true);
+            Delay(spinner.Duration, true);
 
             FadeOut(160);
 

osu.Game.Modes.Osu/Objects/Drawables/Pieces/SliderBall.cs

@@ -51,7 +51,7 @@ namespace osu.Game.Modes.Osu.Objects.Drawables.Pieces
                     {
                         new Box
                         {
-                            Colour = slider.Colour,
+                            Colour = slider.ComboColour,
                             Alpha = 0.4f,
                             Width = width,
                             Height = width,

osu.Game.Modes.Osu/Objects/Drawables/Pieces/SliderBody.cs

@@ -110,10 +110,10 @@ namespace osu.Game.Modes.Osu.Objects.Drawables.Pieces
                 {
                     progress -= border_portion;
 
-                    bytes[i * 4] = (byte)(slider.Colour.R * 255);
+                    bytes[i * 4] = (byte)(slider.ComboColour.R * 255);
-                    bytes[i * 4 + 1] = (byte)(slider.Colour.G * 255);
+                    bytes[i * 4 + 1] = (byte)(slider.ComboColour.G * 255);
-                    bytes[i * 4 + 2] = (byte)(slider.Colour.B * 255);
+                    bytes[i * 4 + 2] = (byte)(slider.ComboColour.B * 255);
-                    bytes[i * 4 + 3] = (byte)((opacity_at_edge - (opacity_at_edge - opacity_at_centre) * progress / gradient_portion) * (slider.Colour.A * 255));
+                    bytes[i * 4 + 3] = (byte)((opacity_at_edge - (opacity_at_edge - opacity_at_centre) * progress / gradient_portion) * (slider.ComboColour.A * 255));
                 }
             }
 

osu.Game.Modes.Osu/Objects/HitObjectType.cs

@@ -0,0 +1,10 @@
+namespace osu.Game.Modes.Osu.Objects
+{
+    public enum HitObjectType
+    {
+        Circle,
+        Slider,
+        Spinner,
+        SliderTick
+    }
+}

osu.Game.Modes.Osu/Objects/OsuHitObject.cs

@@ -1,15 +1,16 @@
 // 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.Game.Modes.Objects;
 using OpenTK;
 using osu.Game.Beatmaps;
 using osu.Game.Modes.Osu.Objects.Drawables;
+using osu.Game.Modes.Objects.Types;
+using OpenTK.Graphics;
 
 namespace osu.Game.Modes.Osu.Objects
 {
-    public abstract class OsuHitObject : HitObject
+    public abstract class OsuHitObject : HitObject, IHasCombo
     {
         public const double OBJECT_RADIUS = 64;
 
@@ -36,6 +37,12 @@ namespace osu.Game.Modes.Osu.Objects
 
         public abstract HitObjectType Type { get; }
 
+        public virtual bool NewCombo { get; set; }
+
+        public Color4 ComboColour { get; set; }
+
+        public int ComboIndex { get; set; }
+
         public double HitWindowFor(OsuScoreResult result)
         {
             switch (result)
@@ -69,16 +76,4 @@ namespace osu.Game.Modes.Osu.Objects
             Scale = (1.0f - 0.7f * (beatmap.BeatmapInfo.BaseDifficulty.CircleSize - 5) / 5) / 2;
         }
     }
-
-    [Flags]
-    public enum HitObjectType
-    {
-        Circle = 1 << 0,
-        Slider = 1 << 1,
-        NewCombo = 1 << 2,
-        Spinner = 1 << 3,
-        ColourHax = 122,
-        Hold = 1 << 7,
-        SliderTick = 1 << 8,
-    }
 }

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

@@ -5,14 +5,16 @@ using OpenTK;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.Samples;
 using osu.Game.Beatmaps.Timing;
+using osu.Game.Modes.Objects.Types;
 using System;
 using System.Collections.Generic;
 
 namespace osu.Game.Modes.Osu.Objects
 {
-    public class Slider : OsuHitObject
+    public class Slider : OsuHitObject, IHasEndTime
     {
-        public override double EndTime => StartTime + RepeatCount * Curve.Length / Velocity;
+        public double EndTime => StartTime + RepeatCount * Curve.Length / Velocity;
+        public double Duration => EndTime - StartTime;
 
         public override Vector2 EndPosition => PositionAt(1);
 
@@ -64,7 +66,7 @@ namespace osu.Game.Modes.Osu.Objects
             set { Curve.Length = value; }
         }
 
-        public CurveTypes CurveType
+        public CurveType CurveType
         {
             get { return Curve.CurveType; }
             set { Curve.CurveType = value; }
@@ -124,7 +126,7 @@ namespace osu.Game.Modes.Osu.Objects
                             Position = Curve.PositionAt(distanceProgress),
                             StackHeight = StackHeight,
                             Scale = Scale,
-                            Colour = Colour,
+                            ComboColour = ComboColour,
                             Sample = new HitSampleInfo
                             {
                                 Type = SampleType.None,
@@ -138,12 +140,4 @@ namespace osu.Game.Modes.Osu.Objects
 
         public override HitObjectType Type => HitObjectType.Slider;
     }
-
-    public enum CurveTypes
-    {
-        Catmull,
-        Bezier,
-        Linear,
-        PerfectCurve
-    }
 }

osu.Game.Modes.Osu/Objects/SliderCurve.cs

@@ -5,6 +5,7 @@ using System.Collections.Generic;
 using OpenTK;
 using System.Linq;
 using osu.Framework.MathUtils;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Modes.Osu.Objects
 {
@@ -14,7 +15,7 @@ namespace osu.Game.Modes.Osu.Objects
 
         public List<Vector2> ControlPoints;
 
-        public CurveTypes CurveType = CurveTypes.PerfectCurve;
+        public CurveType CurveType = CurveType.PerfectCurve;
 
         public Vector2 Offset;
 
@@ -25,9 +26,9 @@ namespace osu.Game.Modes.Osu.Objects
         {
             switch (CurveType)
             {
-                case CurveTypes.Linear:
+                case CurveType.Linear:
                     return subControlPoints;
-                case CurveTypes.PerfectCurve:
+                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)
                         break;

osu.Game.Modes.Osu/Objects/Spinner.cs

@@ -1,14 +1,18 @@
 // 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.Modes.Objects.Types;
+
 namespace osu.Game.Modes.Osu.Objects
 {
-    public class Spinner : OsuHitObject
+    public class Spinner : OsuHitObject, IHasEndTime
     {
-        public double Length;
+        public double EndTime { get; set; }
-
+        public double Duration => EndTime - StartTime;
-        public override double EndTime => StartTime + Length;
 
         public override HitObjectType Type => HitObjectType.Spinner;
+
+        public override bool NewCombo => true;
+
     }
 }

osu.Game.Modes.Osu/OsuAutoReplay.cs

@@ -10,6 +10,7 @@ using osu.Framework.Graphics.Transforms;
 using osu.Game.Modes.Osu.Objects.Drawables;
 using osu.Framework.MathUtils;
 using System.Diagnostics;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Modes.Osu
 {
@@ -100,20 +101,22 @@ namespace osu.Game.Modes.Osu
                 {
                     OsuHitObject last = (OsuHitObject)beatmap.HitObjects[i - 1];
 
+                    double endTime = (last as IHasEndTime)?.EndTime ?? last.StartTime;
+
                     //Make the cursor stay at a hitObject as long as possible (mainly for autopilot).
-                    if (h.StartTime - h.HitWindowFor(OsuScoreResult.Miss) > last.EndTime + h.HitWindowFor(OsuScoreResult.Hit50) + 50)
+                    if (h.StartTime - h.HitWindowFor(OsuScoreResult.Miss) > endTime + h.HitWindowFor(OsuScoreResult.Hit50) + 50)
                     {
-                        if (!(last is Spinner) && h.StartTime - last.EndTime < 1000) addFrameToReplay(new LegacyReplayFrame(last.EndTime + h.HitWindowFor(OsuScoreResult.Hit50), last.EndPosition.X, last.EndPosition.Y, LegacyButtonState.None));
+                        if (!(last is Spinner) && h.StartTime - endTime < 1000) addFrameToReplay(new LegacyReplayFrame(endTime + h.HitWindowFor(OsuScoreResult.Hit50), last.EndPosition.X, last.EndPosition.Y, LegacyButtonState.None));
                         if (!(h is Spinner)) addFrameToReplay(new LegacyReplayFrame(h.StartTime - h.HitWindowFor(OsuScoreResult.Miss), h.Position.X, h.Position.Y, LegacyButtonState.None));
                     }
-                    else if (h.StartTime - h.HitWindowFor(OsuScoreResult.Hit50) > last.EndTime + h.HitWindowFor(OsuScoreResult.Hit50) + 50)
+                    else if (h.StartTime - h.HitWindowFor(OsuScoreResult.Hit50) > endTime + h.HitWindowFor(OsuScoreResult.Hit50) + 50)
                     {
-                        if (!(last is Spinner) && h.StartTime - last.EndTime < 1000) addFrameToReplay(new LegacyReplayFrame(last.EndTime + h.HitWindowFor(OsuScoreResult.Hit50), last.EndPosition.X, last.EndPosition.Y, LegacyButtonState.None));
+                        if (!(last is Spinner) && h.StartTime - endTime < 1000) addFrameToReplay(new LegacyReplayFrame(endTime + h.HitWindowFor(OsuScoreResult.Hit50), last.EndPosition.X, last.EndPosition.Y, LegacyButtonState.None));
                         if (!(h is Spinner)) addFrameToReplay(new LegacyReplayFrame(h.StartTime - h.HitWindowFor(OsuScoreResult.Hit50), h.Position.X, h.Position.Y, LegacyButtonState.None));
                     }
-                    else if (h.StartTime - h.HitWindowFor(OsuScoreResult.Hit100) > last.EndTime + h.HitWindowFor(OsuScoreResult.Hit100) + 50)
+                    else if (h.StartTime - h.HitWindowFor(OsuScoreResult.Hit100) > endTime + h.HitWindowFor(OsuScoreResult.Hit100) + 50)
                     {
-                        if (!(last is Spinner) && h.StartTime - last.EndTime < 1000) addFrameToReplay(new LegacyReplayFrame(last.EndTime + h.HitWindowFor(OsuScoreResult.Hit100), last.EndPosition.X, last.EndPosition.Y, LegacyButtonState.None));
+                        if (!(last is Spinner) && h.StartTime - endTime < 1000) addFrameToReplay(new LegacyReplayFrame(endTime + h.HitWindowFor(OsuScoreResult.Hit100), last.EndPosition.X, last.EndPosition.Y, LegacyButtonState.None));
                         if (!(h is Spinner)) addFrameToReplay(new LegacyReplayFrame(h.StartTime - h.HitWindowFor(OsuScoreResult.Hit100), h.Position.X, h.Position.Y, LegacyButtonState.None));
                     }
                 }
@@ -206,8 +209,10 @@ namespace osu.Game.Modes.Osu
 
                 LegacyButtonState button = buttonIndex % 2 == 0 ? LegacyButtonState.Left1 : LegacyButtonState.Right1;
 
+                double hEndTime = (h as IHasEndTime)?.EndTime ?? h.StartTime;
+
                 LegacyReplayFrame newFrame = new LegacyReplayFrame(h.StartTime, targetPosition.X, targetPosition.Y, button);
-                LegacyReplayFrame endFrame = new LegacyReplayFrame(h.EndTime + endDelay, h.EndPosition.X, h.EndPosition.Y, LegacyButtonState.None);
+                LegacyReplayFrame endFrame = new LegacyReplayFrame(hEndTime + endDelay, h.EndPosition.X, h.EndPosition.Y, LegacyButtonState.None);
 
                 // Decrement because we want the previous frame, not the next one
                 int index = findInsertionIndex(newFrame) - 1;
@@ -251,6 +256,8 @@ namespace osu.Game.Modes.Osu
                 // We add intermediate frames for spinning / following a slider here.
                 if (h is Spinner)
                 {
+                    Spinner s = h as Spinner;
+
                     Vector2 difference = targetPosition - spinner_centre;
 
                     float radius = difference.Length;
@@ -258,7 +265,7 @@ namespace osu.Game.Modes.Osu
 
                     double t;
 
-                    for (double j = h.StartTime + frameDelay; j < h.EndTime; j += frameDelay)
+                    for (double j = h.StartTime + frameDelay; j < s.EndTime; j += frameDelay)
                     {
                         t = applyModsToTime(j - h.StartTime) * spinnerDirection;
 
@@ -266,10 +273,10 @@ namespace osu.Game.Modes.Osu
                         addFrameToReplay(new LegacyReplayFrame((int)j, pos.X, pos.Y, button));
                     }
 
-                    t = applyModsToTime(h.EndTime - h.StartTime) * spinnerDirection;
+                    t = applyModsToTime(s.EndTime - h.StartTime) * spinnerDirection;
                     Vector2 endPosition = spinner_centre + circlePosition(t / 20 + angle, spin_radius);
 
-                    addFrameToReplay(new LegacyReplayFrame(h.EndTime, endPosition.X, endPosition.Y, button));
+                    addFrameToReplay(new LegacyReplayFrame(s.EndTime, endPosition.X, endPosition.Y, button));
 
                     endFrame.MouseX = endPosition.X;
                     endFrame.MouseY = endPosition.Y;
@@ -284,7 +291,7 @@ namespace osu.Game.Modes.Osu
                         addFrameToReplay(new LegacyReplayFrame(h.StartTime + j, pos.X, pos.Y, button));
                     }
 
-                    addFrameToReplay(new LegacyReplayFrame(h.EndTime, s.EndPosition.X, s.EndPosition.Y, button));
+                    addFrameToReplay(new LegacyReplayFrame(s.EndTime, s.EndPosition.X, s.EndPosition.Y, button));
                 }
 
                 // We only want to let go of our button if we are at the end of the current replay. Otherwise something is still going on after us so we need to keep the button pressed!

osu.Game.Modes.Osu/OsuRuleset.cs

@@ -4,7 +4,6 @@
 using OpenTK.Input;
 using osu.Game.Beatmaps;
 using osu.Game.Graphics;
-using osu.Game.Modes.Objects;
 using osu.Game.Modes.Osu.Objects;
 using osu.Game.Modes.Osu.UI;
 using osu.Game.Modes.UI;
@@ -94,8 +93,6 @@ namespace osu.Game.Modes.Osu
 
         public override FontAwesome Icon => FontAwesome.fa_osu_osu_o;
 
-        public override HitObjectParser CreateHitObjectParser() => new OsuHitObjectParser();
-
         public override ScoreProcessor CreateScoreProcessor(int hitObjectCount = 0) => new OsuScoreProcessor(hitObjectCount);
 
         public override DifficultyCalculator CreateDifficultyCalculator(Beatmap beatmap) => new OsuDifficultyCalculator(beatmap);

osu.Game.Modes.Osu/osu.Game.Modes.Osu.csproj

@@ -67,8 +67,8 @@
     <Compile Include="Objects\Drawables\Pieces\TrianglesPiece.cs" />
     <Compile Include="Objects\Drawables\Pieces\SliderBall.cs" />
     <Compile Include="Objects\Drawables\Pieces\SliderBody.cs" />
+    <Compile Include="Objects\HitObjectType.cs" />
     <Compile Include="Objects\OsuHitObjectDifficulty.cs" />
-    <Compile Include="Objects\OsuHitObjectParser.cs" />
     <Compile Include="Objects\SliderCurve.cs" />
     <Compile Include="Objects\SliderTick.cs" />
     <Compile Include="OsuAutoReplay.cs" />

osu.Game.Modes.Taiko/Beatmaps/TaikoBeatmapConverter.cs

@@ -9,7 +9,7 @@ namespace osu.Game.Modes.Taiko.Beatmaps
 {
     internal class TaikoBeatmapConverter : IBeatmapConverter<TaikoBaseHit>
     {
-        public Beatmap<TaikoBaseHit> Convert(Beatmap original)
+        public Beatmap<TaikoBaseHit> ConvertBeatmap(Beatmap original)
         {
             return new Beatmap<TaikoBaseHit>(original)
             {

osu.Game.Modes.Taiko/Objects/Drawable/DrawableTaikoHit.cs

@@ -7,6 +7,7 @@ using osu.Framework.Graphics.Sprites;
 using osu.Framework.Graphics.Textures;
 using osu.Framework.Graphics.Transforms;
 using OpenTK;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Modes.Taiko.Objects.Drawable
 {
@@ -29,8 +30,11 @@ namespace osu.Game.Modes.Taiko.Objects.Drawable
         {
             Texture = textures.Get(@"Menu/logo");
 
+            double endTime = (h as IHasEndTime)?.EndTime ?? h.StartTime;
+            double duration = endTime - h.StartTime;
+
             Transforms.Add(new TransformPositionX { StartTime = h.StartTime - 200, EndTime = h.StartTime, StartValue = 1.1f, EndValue = 0.1f });
-            Transforms.Add(new TransformAlpha { StartTime = h.StartTime + h.Duration + 200, EndTime = h.StartTime + h.Duration + 400, StartValue = 1, EndValue = 0 });
+            Transforms.Add(new TransformAlpha { StartTime = h.StartTime + duration + 200, EndTime = h.StartTime + duration + 400, StartValue = 1, EndValue = 0 });
             Expire(true);
         }
     }

osu.Game.Modes.Taiko/Objects/TaikoConverter.cs

@@ -1,39 +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 System.Collections.Generic;
-using osu.Game.Modes.Objects;
-using osu.Game.Modes.Osu.Objects;
-using osu.Game.Beatmaps;
-
-namespace osu.Game.Modes.Taiko.Objects
-{
-    internal class TaikoConverter : HitObjectConverter<TaikoBaseHit>
-    {
-        public override List<TaikoBaseHit> Convert(Beatmap beatmap)
-        {
-            List<TaikoBaseHit> output = new List<TaikoBaseHit>();
-
-            foreach (HitObject i in beatmap.HitObjects)
-            {
-                TaikoBaseHit h = i as TaikoBaseHit;
-
-                if (h == null)
-                {
-                    OsuHitObject o = i as OsuHitObject;
-
-                    if (o == null) throw new HitObjectConvertException(@"Taiko", i);
-
-                    h = new TaikoBaseHit
-                    {
-                        StartTime = o.StartTime,
-                    };
-                }
-
-                output.Add(h);
-            }
-
-            return output;
-        }
-    }
-}

osu.Game.Modes.Taiko/TaikoRuleset.cs

@@ -4,7 +4,6 @@
 using OpenTK.Input;
 using osu.Game.Beatmaps;
 using osu.Game.Graphics;
-using osu.Game.Modes.Objects;
 using osu.Game.Modes.Taiko.UI;
 using osu.Game.Modes.UI;
 using osu.Game.Screens.Play;
@@ -89,8 +88,6 @@ namespace osu.Game.Modes.Taiko
 
         public override ScoreProcessor CreateScoreProcessor(int hitObjectCount = 0) => null;
 
-        public override HitObjectParser CreateHitObjectParser() => new NullHitObjectParser();
-
         public override DifficultyCalculator CreateDifficultyCalculator(Beatmap beatmap) => new TaikoDifficultyCalculator(beatmap);
     }
 }

osu.Game.Modes.Taiko/osu.Game.Modes.Taiko.csproj

@@ -51,7 +51,6 @@
     <Compile Include="TaikoDifficultyCalculator.cs" />
     <Compile Include="Objects\Drawable\DrawableTaikoHit.cs" />
     <Compile Include="Objects\TaikoBaseHit.cs" />
-    <Compile Include="Objects\TaikoConverter.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="UI\TaikoHitRenderer.cs" />
     <Compile Include="UI\TaikoPlayfield.cs" />

osu.Game/Beatmaps/DifficultyCalculator.cs

@@ -33,7 +33,7 @@ namespace osu.Game.Beatmaps
 
         protected DifficultyCalculator(Beatmap beatmap)
         {
-            Objects = CreateBeatmapConverter().Convert(beatmap).HitObjects;
+            Objects = CreateBeatmapConverter().ConvertBeatmap(beatmap).HitObjects;
             PreprocessHitObjects();
         }
 

osu.Game/Beatmaps/Formats/BeatmapDecoder.cs

@@ -8,6 +8,7 @@ using osu.Game.Modes.Objects;
 using OpenTK.Graphics;
 using osu.Game.Beatmaps.Timing;
 using osu.Game.Database;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Beatmaps.Formats
 {
@@ -81,8 +82,13 @@ namespace osu.Game.Beatmaps.Formats
 
             foreach (HitObject h in b.HitObjects)
             {
-                if (h.NewCombo || i == -1) i = (i + 1) % colours.Count;
+                IHasCombo ihc = h as IHasCombo;
-                h.Colour = colours[i];
+
+                if (ihc == null)
+                    continue;
+
+                if (ihc.NewCombo || i == -1) i = (i + 1) % colours.Count;
+                ihc.ComboColour = colours[i];
             }
         }
     }

osu.Game/Beatmaps/Formats/OsuLegacyDecoder.cs

@@ -265,7 +265,7 @@ namespace osu.Game.Beatmaps.Formats
                 {
                     case Section.General:
                         handleGeneral(beatmap, key, val);
-                        parser = Ruleset.GetRuleset(beatmap.BeatmapInfo.Mode).CreateHitObjectParser();
+                        parser = new LegacyHitObjectParser();
                         break;
                     case Section.Editor:
                         handleEditor(beatmap, key, val);

osu.Game/Beatmaps/IBeatmapCoverter.cs

@@ -5,8 +5,17 @@ using osu.Game.Modes.Objects;
 
 namespace osu.Game.Beatmaps
 {
+    /// <summary>
+    /// Converts a Beatmap for another mode.
+    /// </summary>
+    /// <typeparam name="T">The type of HitObject stored in the Beatmap.</typeparam>
     public interface IBeatmapConverter<T> where T : HitObject
     {
-        Beatmap<T> Convert(Beatmap original);
+        /// <summary>
+        /// Converts a Beatmap to another mode.
+        /// </summary>
+        /// <param name="original">The original Beatmap.</param>
+        /// <returns>The converted Beatmap.</returns>
+        Beatmap<T> ConvertBeatmap(Beatmap original);
     }
 }

osu.Game/Modes/Objects/Drawables/DrawableHitObject.cs

@@ -11,6 +11,7 @@ using osu.Framework.Audio.Sample;
 using osu.Game.Beatmaps.Samples;
 using OpenTK;
 using Container = osu.Framework.Graphics.Containers.Container;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Modes.Objects.Drawables
 {
@@ -67,14 +68,14 @@ namespace osu.Game.Modes.Objects.Drawables
         }
     }
 
-    public abstract class DrawableHitObject<HitObjectType> : DrawableHitObject
+    public abstract class DrawableHitObject<TObject> : DrawableHitObject
-        where HitObjectType : HitObject
+        where TObject : HitObject
     {
-        public event Action<DrawableHitObject<HitObjectType>, JudgementInfo> OnJudgement;
+        public event Action<DrawableHitObject<TObject>, JudgementInfo> OnJudgement;
 
-        public HitObjectType HitObject;
+        public TObject HitObject;
 
-        protected DrawableHitObject(HitObjectType hitObject)
+        protected DrawableHitObject(TObject hitObject)
         {
             HitObject = hitObject;
         }
@@ -88,7 +89,9 @@ namespace osu.Game.Modes.Objects.Drawables
             if (Judgement.Result != null)
                 return false;
 
-            Judgement.TimeOffset = Time.Current - HitObject.EndTime;
+            double endTime = (HitObject as IHasEndTime)?.EndTime ?? HitObject.StartTime;
+
+            Judgement.TimeOffset = Time.Current - endTime;
 
             CheckJudgement(userTriggered);
 
@@ -138,14 +141,14 @@ namespace osu.Game.Modes.Objects.Drawables
             Sample = audio.Sample.Get($@"Gameplay/{sampleSet.ToString().ToLower()}-hit{type.ToString().ToLower()}");
         }
 
-        private List<DrawableHitObject<HitObjectType>> nestedHitObjects;
+        private List<DrawableHitObject<TObject>> nestedHitObjects;
 
-        protected IEnumerable<DrawableHitObject<HitObjectType>> NestedHitObjects => nestedHitObjects;
+        protected IEnumerable<DrawableHitObject<TObject>> NestedHitObjects => nestedHitObjects;
 
-        protected void AddNested(DrawableHitObject<HitObjectType> h)
+        protected void AddNested(DrawableHitObject<TObject> h)
         {
             if (nestedHitObjects == null)
-                nestedHitObjects = new List<DrawableHitObject<HitObjectType>>();
+                nestedHitObjects = new List<DrawableHitObject<TObject>>();
 
             h.OnJudgement += (d, j) => { OnJudgement?.Invoke(d, j); } ;
             nestedHitObjects.Add(h);

osu.Game/Modes/Objects/Hit.cs

@@ -0,0 +1,15 @@
+using osu.Game.Modes.Objects.Types;
+using OpenTK;
+using OpenTK.Graphics;
+
+namespace osu.Game.Modes.Objects
+{
+    internal class Hit : HitObject, IHasPosition, IHasCombo
+    {
+        public Vector2 Position { get; set; }
+        public Color4 ComboColour { get; set; }
+
+        public bool NewCombo { get; set; }
+        public int ComboIndex { get; set; }
+    }
+}

osu.Game/Modes/Objects/HitObject.cs

@@ -3,28 +3,31 @@
 
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.Samples;
-using OpenTK.Graphics;
 
 namespace osu.Game.Modes.Objects
 {
     /// <summary>
-    /// A hitobject describes a point in a beatmap 
+    /// A HitObject describes an object in a Beatmap.
+    /// <para>
+    /// HitObjects may contain more properties for which you should be checking through the IHas* types.
+    /// </para>
     /// </summary>
-    public abstract class HitObject
+    public class HitObject
     {
-        public double StartTime;
+        /// <summary>
-        public virtual double EndTime => StartTime;
+        /// The time at which the HitObject starts.
+        /// </summary>
+        public double StartTime { get; set; }
 
-        public bool NewCombo { get; set; }
+        /// <summary>
-
+        /// The sample to be played when this HitObject is hit.
-        public Color4 Colour = new Color4(17, 136, 170, 255);
+        /// </summary>
-
+        public HitSampleInfo Sample { get; set; }
-        public double Duration => EndTime - StartTime;
-
-        public HitSampleInfo Sample;
-
-        public int ComboIndex;
 
+        /// <summary>
+        /// Sets default parameters from a beatmap.
+        /// </summary>
+        /// <param name="beatmap">The beatmap to set from.</param>
         public virtual void SetDefaultsFromBeatmap(Beatmap beatmap) { }
     }
 }

osu.Game/Modes/Objects/HitObjectConverter.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.Beatmaps;
-using System;
-using System.Collections.Generic;
-
-namespace osu.Game.Modes.Objects
-{
-    public abstract class HitObjectConverter<T>
-        where T : HitObject
-    {
-        public abstract List<T> Convert(Beatmap beatmap);
-    }
-
-    public class HitObjectConvertException : Exception
-    {
-        public HitObject Input { get; }
-        public HitObjectConvertException(string modeName, HitObject input)
-            : base($@"Can't convert from {input.GetType().Name} to {modeName} HitObject!")
-        {
-            Input = input;
-        }
-    }
-}

osu.Game/Modes/Objects/IHitObjectConverter.cs

@@ -0,0 +1,17 @@
+namespace osu.Game.Modes.Objects
+{
+    /// <summary>
+    /// Converts HitObjects to another mode.
+    /// </summary>
+    /// <typeparam name="T">The type of HitObject to be converted to.</typeparam>
+    public interface IHitObjectConverter<T>
+        where T : HitObject
+    {
+        /// <summary>
+        /// Converts a <see cref="HitObject"/> to another mode.
+        /// </summary>
+        /// <param name="hitObject">The base HitObject to convert.</param>
+        /// <returns>The converted HitObject.</returns>
+        T Convert(HitObject hitObject);
+    }
+}

osu.Game/Modes/Objects/LegacyHitObjectParser.cs

@@ -1,16 +1,13 @@
-// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+using OpenTK;
-// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+using osu.Game.Beatmaps.Samples;
-
+using osu.Game.Modes.Objects.Types;
 using System;
 using System.Collections.Generic;
 using System.Globalization;
-using osu.Game.Beatmaps.Samples;
-using osu.Game.Modes.Objects;
-using OpenTK;
 
-namespace osu.Game.Modes.Osu.Objects
+namespace osu.Game.Modes.Objects
 {
-    public class OsuHitObjectParser : HitObjectParser
+    internal class LegacyHitObjectParser : HitObjectParser
     {
         public override HitObject Parse(string text)
         {
@@ -19,17 +16,19 @@ namespace osu.Game.Modes.Osu.Objects
             bool combo = type.HasFlag(HitObjectType.NewCombo);
             type &= (HitObjectType)0xF;
             type &= ~HitObjectType.NewCombo;
-            OsuHitObject result;
+
+            HitObject result;
             switch (type)
             {
                 case HitObjectType.Circle:
-                    result = new HitCircle
+                    result = new Hit
                     {
-                        Position = new Vector2(int.Parse(split[0]), int.Parse(split[1]))
+                        Position = new Vector2(int.Parse(split[0]), int.Parse(split[1])),
+                        NewCombo = combo
                     };
                     break;
                 case HitObjectType.Slider:
-                    CurveTypes curveType = CurveTypes.Catmull;
+                    CurveType curveType = CurveType.Catmull;
                     double length = 0;
                     List<Vector2> points = new List<Vector2> { new Vector2(int.Parse(split[0]), int.Parse(split[1])) };
 
@@ -41,16 +40,16 @@ namespace osu.Game.Modes.Osu.Objects
                             switch (t)
                             {
                                 case @"C":
-                                    curveType = CurveTypes.Catmull;
+                                    curveType = CurveType.Catmull;
                                     break;
                                 case @"B":
-                                    curveType = CurveTypes.Bezier;
+                                    curveType = CurveType.Bezier;
                                     break;
                                 case @"L":
-                                    curveType = CurveTypes.Linear;
+                                    curveType = CurveType.Linear;
                                     break;
                                 case @"P":
-                                    curveType = CurveTypes.PerfectCurve;
+                                    curveType = CurveType.PerfectCurve;
                                     break;
                             }
                             continue;
@@ -75,17 +74,17 @@ namespace osu.Game.Modes.Osu.Objects
                     result = new Slider
                     {
                         ControlPoints = points,
-                        Length = length,
+                        Distance = length,
                         CurveType = curveType,
                         RepeatCount = repeatCount,
-                        Position = new Vector2(int.Parse(split[0]), int.Parse(split[1]))
+                        Position = new Vector2(int.Parse(split[0]), int.Parse(split[1])),
+                        NewCombo = combo
                     };
                     break;
                 case HitObjectType.Spinner:
                     result = new Spinner
                     {
-                        Length = Convert.ToDouble(split[5], CultureInfo.InvariantCulture) - Convert.ToDouble(split[2], CultureInfo.InvariantCulture),
+                        EndTime = Convert.ToDouble(split[5], CultureInfo.InvariantCulture)
-                        Position = new Vector2(512, 384) / 2,
                     };
                     break;
                 default:
@@ -97,8 +96,9 @@ namespace osu.Game.Modes.Osu.Objects
                 Type = (SampleType)int.Parse(split[4]),
                 Set = SampleSet.Soft,
             };
-            result.NewCombo = combo;
+
             // TODO: "addition" field
+
             return result;
         }
     }

osu.Game/Modes/Objects/NullHitObjectParser.cs

@@ -1,13 +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
-
-namespace osu.Game.Modes.Objects
-{
-    /// <summary>
-    /// Returns null HitObjects but at least allows us to run.
-    /// </summary>
-    public class NullHitObjectParser : HitObjectParser
-    {
-        public override HitObject Parse(string text) => null;
-    }
-}

osu.Game/Modes/Objects/Slider.cs

@@ -0,0 +1,23 @@
+using osu.Game.Modes.Objects.Types;
+using System.Collections.Generic;
+using OpenTK;
+using OpenTK.Graphics;
+
+namespace osu.Game.Modes.Objects
+{
+    internal class Slider : HitObject, IHasCurve, IHasDistance, IHasPosition, IHasCombo, IHasRepeats
+    {
+        public List<Vector2> ControlPoints { get; set; }
+        public CurveType CurveType { get; set; }
+
+        public double Distance { get; set; }
+
+        public Vector2 Position { get; set; }
+
+        public Color4 ComboColour { get; set; }
+        public bool NewCombo { get; set; }
+        public int ComboIndex { get; set; }
+
+        public int RepeatCount { get; set; }
+    }
+}

osu.Game/Modes/Objects/Spinner.cs

@@ -0,0 +1,11 @@
+using osu.Game.Modes.Objects.Types;
+
+namespace osu.Game.Modes.Objects
+{
+    internal class Spinner : HitObject, IHasEndTime
+    {
+        public double EndTime { get; set; }
+
+        public double Duration => EndTime - StartTime;
+    }
+}

osu.Game/Modes/Objects/Types/CurveType.cs

@@ -0,0 +1,10 @@
+namespace osu.Game.Modes.Objects.Types
+{
+    public enum CurveType
+    {
+        Catmull,
+        Bezier,
+        Linear,
+        PerfectCurve
+    }
+}

osu.Game/Modes/Objects/Types/IHasCombo.cs

@@ -0,0 +1,25 @@
+using OpenTK.Graphics;
+
+namespace osu.Game.Modes.Objects.Types
+{
+    /// <summary>
+    /// A HitObject that is part of a combo.
+    /// </summary>
+    public interface IHasCombo
+    {
+        /// <summary>
+        /// The colour of this HitObject in the combo.
+        /// </summary>
+        Color4 ComboColour { get; set; }
+
+        /// <summary>
+        /// Whether the HitObject starts a new combo.
+        /// </summary>
+        bool NewCombo { get; }
+
+        /// <summary>
+        /// The combo index.
+        /// </summary>
+        int ComboIndex { get; }
+    }
+}

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

@@ -0,0 +1,21 @@
+using System.Collections.Generic;
+using OpenTK;
+
+namespace osu.Game.Modes.Objects.Types
+{
+    /// <summary>
+    /// A HitObject that has a curve.
+    /// </summary>
+    public interface IHasCurve
+    {
+        /// <summary>
+        /// The control points that shape the curve.
+        /// </summary>
+        List<Vector2> ControlPoints { get; }
+
+        /// <summary>
+        /// The type of curve.
+        /// </summary>
+        CurveType CurveType { get; }
+    }
+}

osu.Game/Modes/Objects/Types/IHasDistance.cs

@@ -0,0 +1,13 @@
+namespace osu.Game.Modes.Objects.Types
+{
+    /// <summary>
+    /// A HitObject that has a distance.
+    /// </summary>
+    public interface IHasDistance
+    {
+        /// <summary>
+        /// The distance of the HitObject.
+        /// </summary>
+        double Distance { get; }
+    }
+}

osu.Game/Modes/Objects/Types/IHasEndTime.cs

@@ -0,0 +1,18 @@
+namespace osu.Game.Modes.Objects.Types
+{
+    /// <summary>
+    /// A HitObject that ends at a different time than its start time.
+    /// </summary>
+    public interface IHasEndTime
+    {
+        /// <summary>
+        /// The time at which the HitObject ends.
+        /// </summary>
+        double EndTime { get; }
+
+        /// <summary>
+        /// The duration of the HitObject.
+        /// </summary>
+        double Duration { get; }
+    }
+}

osu.Game/Modes/Objects/Types/IHasPosition.cs

@@ -0,0 +1,15 @@
+using OpenTK;
+
+namespace osu.Game.Modes.Objects.Types
+{
+    /// <summary>
+    /// A HitObject that has a starting position.
+    /// </summary>
+    public interface IHasPosition
+    {
+        /// <summary>
+        /// The starting position of the HitObject.
+        /// </summary>
+        Vector2 Position { get; }
+    }
+}

osu.Game/Modes/Objects/Types/IHasRepeats.cs

@@ -0,0 +1,13 @@
+namespace osu.Game.Modes.Objects.Types
+{
+    /// <summary>
+    /// A HitObject that spans some length.
+    /// </summary>
+    public interface IHasRepeats
+    {
+        /// <summary>
+        /// The amount of times the HitObject repeats.
+        /// </summary>
+        int RepeatCount { get; }
+    }
+}

osu.Game/Modes/Objects/Types/LegacyHitObjectLive.cs

@@ -0,0 +1,16 @@
+using System;
+
+namespace osu.Game.Modes.Objects.Types
+{
+    [Flags]
+    public enum HitObjectType
+    {
+        Circle = 1 << 0,
+        Slider = 1 << 1,
+        NewCombo = 1 << 2,
+        Spinner = 1 << 3,
+        ColourHax = 122,
+        Hold = 1 << 7,
+        SliderTick = 1 << 8,
+    }
+}

osu.Game/Modes/Ruleset.cs

@@ -3,7 +3,6 @@
 
 using osu.Game.Beatmaps;
 using osu.Game.Graphics;
-using osu.Game.Modes.Objects;
 using osu.Game.Modes.UI;
 using osu.Game.Screens.Play;
 using System;
@@ -33,8 +32,6 @@ namespace osu.Game.Modes
 
         public abstract HitRenderer CreateHitRendererWith(Beatmap beatmap);
 
-        public abstract HitObjectParser CreateHitObjectParser();
-
         public abstract DifficultyCalculator CreateDifficultyCalculator(Beatmap beatmap);
 
         public static void Register(Ruleset ruleset) => availableRulesets.TryAdd(ruleset.PlayMode, ruleset.GetType());

osu.Game/Modes/UI/HitRenderer.cs

@@ -57,7 +57,7 @@ namespace osu.Game.Modes.UI
 
         protected HitRenderer(Beatmap beatmap)
         {
-            Beatmap = CreateBeatmapConverter().Convert(beatmap);
+            Beatmap = CreateBeatmapConverter().ConvertBeatmap(beatmap);
 
             RelativeSizeAxes = Axes.Both;
 

osu.Game/Screens/Select/BeatmapInfoWedge.cs

@@ -21,6 +21,8 @@ using osu.Framework.MathUtils;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Sprites;
 using osu.Game.Modes;
+using osu.Game.Modes.Objects;
+using osu.Game.Modes.Objects.Types;
 
 namespace osu.Game.Screens.Select
 {
@@ -69,11 +71,14 @@ namespace osu.Game.Screens.Select
 
             if (beatmap.Beatmap != null)
             {
+                HitObject lastObject = beatmap.Beatmap.HitObjects.Last();
+                double endTime = (lastObject as IHasEndTime)?.EndTime ?? lastObject.StartTime;
+
                 labels.Add(new InfoLabel(new BeatmapStatistic
                 {
                     Name = "Length",
                     Icon = FontAwesome.fa_clock_o,
-                    Content = beatmap.Beatmap.HitObjects.Count == 0 ? "-" : TimeSpan.FromMilliseconds(beatmap.Beatmap.HitObjects.Last().EndTime - beatmap.Beatmap.HitObjects.First().StartTime).ToString(@"m\:ss"),
+                    Content = beatmap.Beatmap.HitObjects.Count == 0 ? "-" : TimeSpan.FromMilliseconds(endTime - beatmap.Beatmap.HitObjects.First().StartTime).ToString(@"m\:ss"),
                 }));
 
                 labels.Add(new InfoLabel(new BeatmapStatistic

osu.Game/osu.Game.csproj

@@ -91,9 +91,21 @@
     <Compile Include="IO\Legacy\SerializationWriter.cs" />
     <Compile Include="IPC\ScoreIPCChannel.cs" />
     <Compile Include="Modes\LegacyReplay.cs" />
+    <Compile Include="Modes\Objects\Hit.cs" />
+    <Compile Include="Modes\Objects\IHitObjectConverter.cs" />
+    <Compile Include="Modes\Objects\LegacyHitObjectParser.cs" />
+    <Compile Include="Modes\Objects\Slider.cs" />
+    <Compile Include="Modes\Objects\Spinner.cs" />
+    <Compile Include="Modes\Objects\Types\CurveType.cs" />
     <Compile Include="Modes\Objects\Drawables\IDrawableHitObjectWithProxiedApproach.cs" />
     <Compile Include="Modes\Objects\HitObjectParser.cs" />
-    <Compile Include="Modes\Objects\NullHitObjectParser.cs" />
+    <Compile Include="Modes\Objects\Types\IHasCombo.cs" />
+    <Compile Include="Modes\Objects\Types\IHasEndTime.cs" />
+    <Compile Include="Modes\Objects\Types\IHasDistance.cs" />
+    <Compile Include="Modes\Objects\Types\IHasCurve.cs" />
+    <Compile Include="Modes\Objects\Types\IHasRepeats.cs" />
+    <Compile Include="Modes\Objects\Types\IHasPosition.cs" />
+    <Compile Include="Modes\Objects\Types\LegacyHitObjectLive.cs" />
     <Compile Include="Modes\Replay.cs" />
     <Compile Include="Modes\Score.cs" />
     <Compile Include="Modes\ScoreProcesssor.cs" />
@@ -114,7 +126,6 @@
     <Compile Include="Beatmaps\Drawables\Panel.cs" />
     <Compile Include="Modes\Objects\Drawables\DrawableHitObject.cs" />
     <Compile Include="Modes\Objects\HitObject.cs" />
-    <Compile Include="Modes\Objects\HitObjectConverter.cs" />
     <Compile Include="Beatmaps\Samples\HitSampleInfo.cs" />
     <Compile Include="Beatmaps\Samples\SampleBank.cs" />
     <Compile Include="Beatmaps\Samples\SampleInfo.cs" />