Mode -> Ruleset.

osu.Game.Rulesets.Taiko/Objects/BarLine.cs

@@ -0,0 +1,9 @@
+// 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.Taiko.Objects
+{
+    public class BarLine : TaikoHitObject
+    {
+    }
+}

osu.Game.Rulesets.Taiko/Objects/CentreHit.cs

@@ -0,0 +1,9 @@
+// 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.Taiko.Objects
+{
+    public class CentreHit : Hit
+    {
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableBarLine.cs

@@ -0,0 +1,80 @@
+// 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.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
+using OpenTK;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    /// <summary>
+    /// A line that scrolls alongside hit objects in the playfield and visualises control points.
+    /// </summary>
+    public class DrawableBarLine : Container
+    {
+        /// <summary>
+        /// The width of the line tracker.
+        /// </summary>
+        private const float tracker_width = 2f;
+
+        /// <summary>
+        /// Fade out time calibrated to a pre-empt of 1000ms.
+        /// </summary>
+        private const float base_fadeout_time = 100f;
+
+        /// <summary>
+        /// The visual line tracker.
+        /// </summary>
+        protected Box Tracker;
+
+        /// <summary>
+        /// The bar line.
+        /// </summary>
+        protected readonly BarLine BarLine;
+
+        public DrawableBarLine(BarLine barLine)
+        {
+            BarLine = barLine;
+
+            Anchor = Anchor.CentreLeft;
+            Origin = Anchor.Centre;
+
+            RelativePositionAxes = Axes.X;
+            RelativeSizeAxes = Axes.Y;
+
+            Width = tracker_width;
+
+            Children = new[]
+            {
+                Tracker = new Box
+                {
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    RelativeSizeAxes = Axes.Both,
+                    EdgeSmoothness = new Vector2(0.5f, 0),
+                    Alpha = 0.75f
+                }
+            };
+
+            LifetimeStart = BarLine.StartTime - BarLine.ScrollTime * 2;
+            LifetimeEnd = BarLine.StartTime + BarLine.ScrollTime;
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+            Delay(BarLine.StartTime - Time.Current);
+            FadeOut(base_fadeout_time * BarLine.ScrollTime / 1000);
+        }
+
+        private void updateScrollPosition(double time) => MoveToX((float)((BarLine.StartTime - time) / BarLine.ScrollTime));
+
+        protected override void Update()
+        {
+            base.Update();
+
+            updateScrollPosition(Time.Current);
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableBarLineMajor.cs

@@ -0,0 +1,57 @@
+// 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.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
+using OpenTK;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public class DrawableBarLineMajor : DrawableBarLine
+    {
+        /// <summary>
+        /// The vertical offset of the triangles from the line tracker.
+        /// </summary>
+        private const float triangle_offfset = 10f;
+
+        /// <summary>
+        /// The size of the triangles.
+        /// </summary>
+        private const float triangle_size = 20f;
+
+        public DrawableBarLineMajor(BarLine barLine)
+            : base(barLine)
+        {
+            Add(new Container
+            {
+                Anchor = Anchor.Centre,
+                Origin = Anchor.Centre,
+                RelativeSizeAxes = Axes.Both,
+                Children = new[]
+                {
+                    new EquilateralTriangle
+                    {
+                        Name = "Top",
+                        Anchor = Anchor.TopCentre,
+                        Origin = Anchor.TopCentre,
+                        Position = new Vector2(0, -triangle_offfset),
+                        Size = new Vector2(-triangle_size),
+                        EdgeSmoothness = new Vector2(1),
+                    },
+                    new EquilateralTriangle
+                    {
+                        Name = "Bottom",
+                        Anchor = Anchor.BottomCentre,
+                        Origin = Anchor.TopCentre,
+                        Position = new Vector2(0, triangle_offfset),
+                        Size = new Vector2(triangle_size),
+                        EdgeSmoothness = new Vector2(1),
+                    }
+                }
+            });
+
+            Tracker.Alpha = 1f;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableCentreHit.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.Allocation;
+using osu.Game.Graphics;
+using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
+using OpenTK.Input;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public class DrawableCentreHit : DrawableHit
+    {
+        protected override Key[] HitKeys { get; } = { Key.F, Key.J };
+
+        public DrawableCentreHit(Hit hit)
+            : base(hit)
+        {
+            MainPiece.Add(new CentreHitSymbolPiece());
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            MainPiece.AccentColour = colours.PinkDarker;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableCentreHitStrong.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.Allocation;
+using osu.Game.Graphics;
+using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
+using OpenTK.Input;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public class DrawableCentreHitStrong : DrawableHitStrong
+    {
+        protected override Key[] HitKeys { get; } = { Key.F, Key.J };
+
+        public DrawableCentreHitStrong(Hit hit)
+            : base(hit)
+        {
+            MainPiece.Add(new CentreHitSymbolPiece());
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            MainPiece.AccentColour = colours.PinkDarker;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableDrumRoll.cs

@@ -0,0 +1,109 @@
+// 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.Linq;
+using osu.Framework.Allocation;
+using osu.Framework.MathUtils;
+using osu.Game.Graphics;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Taiko.Judgements;
+using OpenTK;
+using OpenTK.Graphics;
+using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public class DrawableDrumRoll : DrawableTaikoHitObject<DrumRoll>
+    {
+        /// <summary>
+        /// Number of rolling hits required to reach the dark/final accent colour.
+        /// </summary>
+        private const int rolling_hits_for_dark_accent = 5;
+
+        private Color4 accentDarkColour;
+
+        /// <summary>
+        /// Rolling number of tick hits. This increases for hits and decreases for misses.
+        /// </summary>
+        private int rollingHits;
+
+        public DrawableDrumRoll(DrumRoll drumRoll)
+            : base(drumRoll)
+        {
+            foreach (var tick in drumRoll.Ticks)
+            {
+                var newTick = new DrawableDrumRollTick(tick)
+                {
+                    X = (float)((tick.StartTime - HitObject.StartTime) / HitObject.Duration)
+                };
+
+                newTick.OnJudgement += onTickJudgement;
+
+                AddNested(newTick);
+                MainPiece.Add(newTick);
+            }
+        }
+
+        protected override TaikoJudgement CreateJudgement() => new TaikoJudgement { SecondHit = HitObject.IsStrong };
+
+        protected override TaikoPiece CreateMainPiece() => new ElongatedCirclePiece(HitObject.IsStrong)
+        {
+            Length = (float)(HitObject.Duration / HitObject.ScrollTime),
+            PlayfieldLengthReference = () => Parent.DrawSize.X
+        };
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            MainPiece.AccentColour = AccentColour = colours.YellowDark;
+            accentDarkColour = colours.YellowDarker;
+        }
+
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            // This is naive, however it's based on the reasoning that the hit target
+            // is further than mid point of the play field, so the time taken to scroll in should always
+            // be greater than the time taken to scroll out to the left of the screen.
+            // Thus, using PreEmpt here is enough for the drum roll to completely scroll out.
+            LifetimeEnd = HitObject.EndTime + HitObject.ScrollTime;
+        }
+
+        private void onTickJudgement(DrawableHitObject<TaikoHitObject, TaikoJudgement> obj)
+        {
+            if (obj.Judgement.Result == HitResult.Hit)
+                rollingHits++;
+            else
+                rollingHits--;
+
+            rollingHits = MathHelper.Clamp(rollingHits, 0, rolling_hits_for_dark_accent);
+
+            Color4 newAccent = Interpolation.ValueAt((float)rollingHits / rolling_hits_for_dark_accent, AccentColour, accentDarkColour, 0, 1);
+            MainPiece.FadeAccent(newAccent, 100);
+        }
+
+        protected override void CheckJudgement(bool userTriggered)
+        {
+            if (userTriggered)
+                return;
+
+            if (Judgement.TimeOffset < 0)
+                return;
+
+            int countHit = NestedHitObjects.Count(o => o.Judgement.Result == HitResult.Hit);
+
+            if (countHit > HitObject.RequiredGoodHits)
+            {
+                Judgement.Result = HitResult.Hit;
+                Judgement.TaikoResult = countHit >= HitObject.RequiredGreatHits ? TaikoHitResult.Great : TaikoHitResult.Good;
+            }
+            else
+                Judgement.Result = HitResult.Miss;
+        }
+
+        protected override void UpdateState(ArmedState state)
+        {
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableDrumRollTick.cs

@@ -0,0 +1,63 @@
+// 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.Objects.Drawables;
+using osu.Game.Rulesets.Taiko.Judgements;
+using OpenTK.Input;
+using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public class DrawableDrumRollTick : DrawableTaikoHitObject<DrumRollTick>
+    {
+        public DrawableDrumRollTick(DrumRollTick tick)
+            : base(tick)
+        {
+        }
+
+        protected override TaikoPiece CreateMainPiece() => new TickPiece
+        {
+            Filled = HitObject.FirstTick
+        };
+
+        protected override TaikoJudgement CreateJudgement() => new TaikoDrumRollTickJudgement { SecondHit = HitObject.IsStrong };
+
+        protected override void CheckJudgement(bool userTriggered)
+        {
+            if (!userTriggered)
+            {
+                if (Judgement.TimeOffset > HitObject.HitWindow)
+                    Judgement.Result = HitResult.Miss;
+                return;
+            }
+
+            if (Math.Abs(Judgement.TimeOffset) < HitObject.HitWindow)
+            {
+                Judgement.Result = HitResult.Hit;
+                Judgement.TaikoResult = TaikoHitResult.Great;
+            }
+        }
+
+        protected override void UpdateState(ArmedState state)
+        {
+            switch (state)
+            {
+                case ArmedState.Hit:
+                    Content.ScaleTo(0, 100, EasingTypes.OutQuint);
+                    break;
+            }
+        }
+
+        protected override void UpdateScrollPosition(double time)
+        {
+            // Ticks don't move
+        }
+
+        protected override bool HandleKeyPress(Key key)
+        {
+            return Judgement.Result == HitResult.None && UpdateJudgement(true);
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableHit.cs

@@ -0,0 +1,109 @@
+// 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.Linq;
+using osu.Framework.Graphics;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Taiko.Judgements;
+using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
+using OpenTK.Input;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public abstract class DrawableHit : DrawableTaikoHitObject<Hit>
+    {
+        /// <summary>
+        /// A list of keys which can result in hits for this HitObject.
+        /// </summary>
+        protected abstract Key[] HitKeys { get; }
+
+        /// <summary>
+        /// Whether the last key pressed is a valid hit key.
+        /// </summary>
+        private bool validKeyPressed;
+
+        protected DrawableHit(Hit hit)
+            : base(hit)
+        {
+        }
+
+        protected override void CheckJudgement(bool userTriggered)
+        {
+            if (!userTriggered)
+            {
+                if (Judgement.TimeOffset > HitObject.HitWindowGood)
+                    Judgement.Result = HitResult.Miss;
+                return;
+            }
+
+            double hitOffset = Math.Abs(Judgement.TimeOffset);
+
+            if (hitOffset > HitObject.HitWindowMiss)
+                return;
+
+            if (!validKeyPressed)
+                Judgement.Result = HitResult.Miss;
+            else if (hitOffset < HitObject.HitWindowGood)
+            {
+                Judgement.Result = HitResult.Hit;
+                Judgement.TaikoResult = hitOffset < HitObject.HitWindowGreat ? TaikoHitResult.Great : TaikoHitResult.Good;
+            }
+            else
+                Judgement.Result = HitResult.Miss;
+        }
+
+        protected override bool HandleKeyPress(Key key)
+        {
+            if (Judgement.Result != HitResult.None)
+                return false;
+
+            validKeyPressed = HitKeys.Contains(key);
+
+            return UpdateJudgement(true);
+        }
+
+        protected override void UpdateState(ArmedState state)
+        {
+            Delay(HitObject.StartTime - Time.Current + Judgement.TimeOffset, true);
+
+            var circlePiece = MainPiece as CirclePiece;
+
+            circlePiece?.FlashBox.Flush();
+
+            switch (State)
+            {
+                case ArmedState.Idle:
+                    Delay(HitObject.HitWindowMiss);
+                    break;
+                case ArmedState.Miss:
+                    FadeOut(100);
+                    break;
+                case ArmedState.Hit:
+                    FadeOut(600);
+
+                    var flash = circlePiece?.FlashBox;
+                    if (flash != null)
+                    {
+                        flash.FadeTo(0.9f);
+                        flash.FadeOut(300);
+                    }
+
+
+                    FadeOut(800);
+
+                    const float gravity_time = 300;
+                    const float gravity_travel_height = 200;
+
+                    Content.ScaleTo(0.8f, gravity_time * 2, EasingTypes.OutQuad);
+
+                    MoveToY(-gravity_travel_height, gravity_time, EasingTypes.Out);
+                    Delay(gravity_time, true);
+                    MoveToY(gravity_travel_height * 2, gravity_time * 2, EasingTypes.In);
+                    break;
+            }
+
+            Expire();
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableHitStrong.cs

@@ -0,0 +1,92 @@
+// 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.Linq;
+using osu.Framework.Input;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Taiko.Judgements;
+using OpenTK.Input;
+using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public abstract class DrawableHitStrong : DrawableHit
+    {
+        /// <summary>
+        /// The lenience for the second key press.
+        /// This does not adjust by map difficulty in ScoreV2 yet.
+        /// </summary>
+        private const double second_hit_window = 30;
+
+        private double firstHitTime;
+        private bool firstKeyHeld;
+        private Key firstHitKey;
+
+        protected DrawableHitStrong(Hit hit)
+            : base(hit)
+        {
+        }
+
+        protected override TaikoPiece CreateMainPiece() => new CirclePiece(true);
+
+        protected override TaikoJudgement CreateJudgement() => new TaikoStrongHitJudgement();
+
+        protected override void CheckJudgement(bool userTriggered)
+        {
+            if (Judgement.Result == HitResult.None)
+            {
+                base.CheckJudgement(userTriggered);
+                return;
+            }
+
+            if (!userTriggered)
+                return;
+
+            // If we get here, we're assured that the key pressed is the correct secondary key
+
+            if (Math.Abs(firstHitTime - Time.Current) < second_hit_window)
+                Judgement.SecondHit = true;
+        }
+
+        protected override bool HandleKeyPress(Key key)
+        {
+            // Check if we've handled the first key
+            if (Judgement.Result == HitResult.None)
+            {
+                // First key hasn't been handled yet, attempt to handle it
+                bool handled = base.HandleKeyPress(key);
+
+                if (handled)
+                {
+                    firstHitTime = Time.Current;
+                    firstHitKey = key;
+                }
+
+                return handled;
+            }
+
+            // If we've already hit the second key, don't handle this object any further
+            if (Judgement.SecondHit)
+                return false;
+
+            // Don't handle represses of the first key
+            if (firstHitKey == key)
+                return false;
+
+            // Don't handle invalid hit key presses
+            if (!HitKeys.Contains(key))
+                return false;
+
+            // Assume the intention was to hit the strong hit with both keys only if the first key is still being held down
+            return firstKeyHeld && UpdateJudgement(true);
+        }
+
+        protected override bool OnKeyDown(InputState state, KeyDownEventArgs args)
+        {
+            firstKeyHeld = state.Keyboard.Keys.Contains(firstHitKey);
+
+            return base.OnKeyDown(state, args);
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableRimHit.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.Allocation;
+using osu.Game.Graphics;
+using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
+using OpenTK.Input;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public class DrawableRimHit : DrawableHit
+    {
+        protected override Key[] HitKeys { get; } = { Key.D, Key.K };
+
+        public DrawableRimHit(Hit hit)
+            : base(hit)
+        {
+            MainPiece.Add(new RimHitSymbolPiece());
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            MainPiece.AccentColour = colours.BlueDarker;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableRimHitStrong.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.Allocation;
+using osu.Game.Graphics;
+using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
+using OpenTK.Input;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public class DrawableRimHitStrong : DrawableHitStrong
+    {
+        protected override Key[] HitKeys { get; } = { Key.D, Key.K };
+
+        public DrawableRimHitStrong(Hit hit)
+            : base(hit)
+        {
+            MainPiece.Add(new RimHitSymbolPiece());
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            MainPiece.AccentColour = colours.BlueDarker;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableSwell.cs

@@ -0,0 +1,243 @@
+// 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.Linq;
+using osu.Framework.Allocation;
+using osu.Framework.Extensions.Color4Extensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
+using osu.Game.Graphics;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Taiko.Judgements;
+using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
+using OpenTK;
+using OpenTK.Graphics;
+using OpenTK.Input;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public class DrawableSwell : DrawableTaikoHitObject<Swell>
+    {
+        /// <summary>
+        /// Invoked when the swell has reached the hit target, i.e. when CurrentTime >= StartTime.
+        /// This is only ever invoked once.
+        /// </summary>
+        public event Action OnStart;
+
+        private const float target_ring_thick_border = 1.4f;
+        private const float target_ring_thin_border = 1f;
+        private const float target_ring_scale = 5f;
+        private const float inner_ring_alpha = 0.65f;
+
+        private readonly Container bodyContainer;
+        private readonly CircularContainer targetRing;
+        private readonly CircularContainer expandingRing;
+
+        private readonly CirclePiece circlePiece;
+
+        private readonly Key[] rimKeys = { Key.D, Key.K };
+        private readonly Key[] centreKeys = { Key.F, Key.J };
+        private Key[] lastKeySet;
+
+        /// <summary>
+        /// The amount of times the user has hit this swell.
+        /// </summary>
+        private int userHits;
+
+        private bool hasStarted;
+        private readonly SwellSymbolPiece symbol;
+
+        public DrawableSwell(Swell swell)
+            : base(swell)
+        {
+            Children = new Drawable[]
+            {
+                bodyContainer = new Container
+                {
+                    AutoSizeAxes = Axes.Both,
+                    Children = new Drawable[]
+                    {
+                        expandingRing = new CircularContainer
+                        {
+                            Name = "Expanding ring",
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            Alpha = 0,
+                            Size = new Vector2(TaikoHitObject.DEFAULT_CIRCLE_DIAMETER),
+                            BlendingMode = BlendingMode.Additive,
+                            Masking = true,
+                            Children = new []
+                            {
+                                new Box
+                                {
+                                    RelativeSizeAxes = Axes.Both,
+                                    Alpha = inner_ring_alpha,
+                                }
+                            }
+                        },
+                        targetRing = new CircularContainer
+                        {
+                            Name = "Target ring (thick border)",
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            Size = new Vector2(TaikoHitObject.DEFAULT_CIRCLE_DIAMETER),
+                            Masking = true,
+                            BorderThickness = target_ring_thick_border,
+                            BlendingMode = BlendingMode.Additive,
+                            Children = new Drawable[]
+                            {
+                                new Box
+                                {
+                                    RelativeSizeAxes = Axes.Both,
+                                    Alpha = 0,
+                                    AlwaysPresent = true
+                                },
+                                new CircularContainer
+                                {
+                                    Name = "Target ring (thin border)",
+                                    Anchor = Anchor.Centre,
+                                    Origin = Anchor.Centre,
+                                    RelativeSizeAxes = Axes.Both,
+                                    Masking = true,
+                                    BorderThickness = target_ring_thin_border,
+                                    BorderColour = Color4.White,
+                                    Children = new[]
+                                    {
+                                        new Box
+                                        {
+                                            RelativeSizeAxes = Axes.Both,
+                                            Alpha = 0,
+                                            AlwaysPresent = true
+                                        }
+                                    }
+                                }
+                            }
+                        },
+                        circlePiece = new CirclePiece
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            Children = new []
+                            {
+                                symbol = new SwellSymbolPiece()
+                            }
+                        }
+                    }
+                }
+            };
+
+            circlePiece.KiaiMode = HitObject.Kiai;
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(OsuColour colours)
+        {
+            circlePiece.AccentColour = colours.YellowDark;
+            expandingRing.Colour = colours.YellowLight;
+            targetRing.BorderColour = colours.YellowDark.Opacity(0.25f);
+        }
+
+        protected override void CheckJudgement(bool userTriggered)
+        {
+            if (userTriggered)
+            {
+                userHits++;
+
+                var completion = (float)userHits / HitObject.RequiredHits;
+
+                expandingRing.FadeTo(expandingRing.Alpha + MathHelper.Clamp(completion / 16, 0.1f, 0.6f), 50);
+                expandingRing.Delay(50);
+                expandingRing.FadeTo(completion / 8, 2000, EasingTypes.OutQuint);
+                expandingRing.DelayReset();
+
+                symbol.RotateTo((float)(completion * HitObject.Duration / 8), 4000, EasingTypes.OutQuint);
+
+                expandingRing.ScaleTo(1f + Math.Min(target_ring_scale - 1f, (target_ring_scale - 1f) * completion * 1.3f), 260, EasingTypes.OutQuint);
+
+                if (userHits == HitObject.RequiredHits)
+                {
+                    Judgement.Result = HitResult.Hit;
+                    Judgement.TaikoResult = TaikoHitResult.Great;
+                }
+            }
+            else
+            {
+                if (Judgement.TimeOffset < 0)
+                    return;
+
+                //TODO: THIS IS SHIT AND CAN'T EXIST POST-TAIKO WORLD CUP
+                if (userHits > HitObject.RequiredHits / 2)
+                {
+                    Judgement.Result = HitResult.Hit;
+                    Judgement.TaikoResult = TaikoHitResult.Good;
+                }
+                else
+                    Judgement.Result = HitResult.Miss;
+            }
+        }
+
+        protected override void UpdateState(ArmedState state)
+        {
+            const float preempt = 100;
+
+            Delay(HitObject.StartTime - Time.Current - preempt, true);
+
+            targetRing.ScaleTo(target_ring_scale, preempt * 4, EasingTypes.OutQuint);
+
+            Delay(preempt, true);
+
+            Delay(Judgement.TimeOffset + HitObject.Duration, true);
+
+            const float out_transition_time = 300;
+
+            switch (state)
+            {
+                case ArmedState.Hit:
+                    bodyContainer.ScaleTo(1.4f, out_transition_time);
+                    break;
+            }
+
+            FadeOut(out_transition_time, EasingTypes.Out);
+
+            Expire();
+        }
+
+        protected override void UpdateScrollPosition(double time)
+        {
+            // Make the swell stop at the hit target
+            double t = Math.Min(HitObject.StartTime, time);
+
+            if (t == HitObject.StartTime && !hasStarted)
+            {
+                OnStart?.Invoke();
+                hasStarted = true;
+            }
+
+            base.UpdateScrollPosition(t);
+        }
+
+        protected override bool HandleKeyPress(Key key)
+        {
+            if (Judgement.Result != HitResult.None)
+                return false;
+
+            // Don't handle keys before the swell starts
+            if (Time.Current < HitObject.StartTime)
+                return false;
+
+            // Find the keyset which this key corresponds to
+            var keySet = rimKeys.Contains(key) ? rimKeys : centreKeys;
+
+            // Ensure alternating keysets
+            if (keySet == lastKeySet)
+                return false;
+            lastKeySet = keySet;
+
+            UpdateJudgement(true);
+
+            return true;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/DrawableTaikoHitObject.cs

@@ -0,0 +1,93 @@
+// 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.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Input;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.Taiko.Judgements;
+using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
+using OpenTK;
+using OpenTK.Input;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables
+{
+    public abstract class DrawableTaikoHitObject<TaikoHitType> : DrawableHitObject<TaikoHitObject, TaikoJudgement>
+        where TaikoHitType : TaikoHitObject
+    {
+        /// <summary>
+        /// A list of keys which this hit object will accept. These are the standard Taiko keys for now.
+        /// These should be moved to bindings later.
+        /// </summary>
+        private readonly List<Key> validKeys = new List<Key>(new[] { Key.D, Key.F, Key.J, Key.K });
+
+        public override Vector2 OriginPosition => new Vector2(DrawHeight / 2);
+
+        protected override Container<Drawable> Content => bodyContainer;
+
+        protected readonly TaikoPiece MainPiece;
+
+        private readonly Container bodyContainer;
+
+        public new TaikoHitType HitObject;
+
+        protected DrawableTaikoHitObject(TaikoHitType hitObject)
+            : base(hitObject)
+        {
+            HitObject = hitObject;
+
+            Anchor = Anchor.CentreLeft;
+            Origin = Anchor.Custom;
+
+            AutoSizeAxes = Axes.Both;
+
+            RelativePositionAxes = Axes.X;
+
+            AddInternal(bodyContainer = new Container
+            {
+                AutoSizeAxes = Axes.Both,
+                Children = new[]
+                {
+                    MainPiece = CreateMainPiece()
+                }
+            });
+
+            MainPiece.KiaiMode = HitObject.Kiai;
+
+            LifetimeStart = HitObject.StartTime - HitObject.ScrollTime * 2;
+        }
+
+        protected override TaikoJudgement CreateJudgement() => new TaikoJudgement();
+
+        protected virtual TaikoPiece CreateMainPiece() => new CirclePiece(HitObject.IsStrong);
+
+        /// <summary>
+        /// Sets the scroll position of the DrawableHitObject relative to the offset between
+        /// a time value and the HitObject's StartTime.
+        /// </summary>
+        /// <param name="time"></param>
+        protected virtual void UpdateScrollPosition(double time) => X = (float)((HitObject.StartTime - time) / HitObject.ScrollTime);
+
+        protected override void Update()
+        {
+            UpdateScrollPosition(Time.Current);
+        }
+
+        protected virtual bool HandleKeyPress(Key key) => false;
+
+        protected override bool OnKeyDown(InputState state, KeyDownEventArgs args)
+        {
+            // Make sure we don't handle held-down keys
+            if (args.Repeat)
+                return false;
+
+            // Check if we've pressed a valid taiko key
+            if (!validKeys.Contains(args.Key))
+                return false;
+
+            // Handle it!
+            return HandleKeyPress(args.Key);
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/Pieces/CentreHitSymbolPiece.cs

@@ -0,0 +1,31 @@
+// 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.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
+using OpenTK;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces
+{
+    /// <summary>
+    /// The symbol used for centre hit pieces.
+    /// </summary>
+    public class CentreHitSymbolPiece : CircularContainer
+    {
+        public CentreHitSymbolPiece()
+        {
+            Anchor = Anchor.Centre;
+            Origin = Anchor.Centre;
+            Size = new Vector2(CirclePiece.SYMBOL_INNER_SIZE);
+            Masking = true;
+            Children = new[]
+            {
+                new Box
+                {
+                    RelativeSizeAxes = Axes.Both
+                }
+            };
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/Pieces/CirclePiece.cs

@@ -0,0 +1,152 @@
+// 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.Extensions.Color4Extensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
+using osu.Game.Graphics.Backgrounds;
+using OpenTK.Graphics;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces
+{
+    /// <summary>
+    /// A circle piece which is used uniformly through osu!taiko to visualise hitobjects.
+    /// <para>
+    /// Note that this can actually be non-circle if the width is changed. See <see cref="ElongatedCirclePiece"/>
+    /// for a usage example.
+    /// </para>
+    /// </summary>
+    public class CirclePiece : TaikoPiece
+    {
+        public const float SYMBOL_SIZE = TaikoHitObject.DEFAULT_CIRCLE_DIAMETER * 0.45f;
+        public const float SYMBOL_BORDER = 8;
+        public const float SYMBOL_INNER_SIZE = SYMBOL_SIZE - 2 * SYMBOL_BORDER;
+
+        /// <summary>
+        /// The colour of the inner circle and outer glows.
+        /// </summary>
+        public override Color4 AccentColour
+        {
+            get { return base.AccentColour; }
+            set
+            {
+                base.AccentColour = value;
+
+                background.Colour = AccentColour;
+
+                resetEdgeEffects();
+            }
+        }
+
+        /// <summary>
+        /// Whether Kiai mode effects are enabled for this circle piece.
+        /// </summary>
+        public override bool KiaiMode
+        {
+            get { return base.KiaiMode; }
+            set
+            {
+                base.KiaiMode = value;
+
+                resetEdgeEffects();
+            }
+        }
+
+        protected override Container<Drawable> Content => content;
+
+        private readonly Container content;
+
+        private readonly Container background;
+
+        public Box FlashBox;
+
+        public CirclePiece(bool isStrong = false)
+        {
+            AddInternal(new Drawable[]
+            {
+                background = new CircularContainer
+                {
+                    Name = "Background",
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    RelativeSizeAxes = Axes.Both,
+                    Masking = true,
+                    Children = new Drawable[]
+                    {
+                        new Box
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            RelativeSizeAxes = Axes.Both,
+                        },
+                        new Triangles
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            RelativeSizeAxes = Axes.Both,
+                            ColourLight = Color4.White,
+                            ColourDark = Color4.White.Darken(0.1f)
+                        }
+                    }
+                },
+                new CircularContainer
+                {
+                    Name = "Ring",
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                    RelativeSizeAxes = Axes.Both,
+                    BorderThickness = 8,
+                    BorderColour = Color4.White,
+                    Masking = true,
+                    Children = new[]
+                    {
+                        FlashBox = new Box
+                        {
+                            Anchor = Anchor.Centre,
+                            Origin = Anchor.Centre,
+                            RelativeSizeAxes = Axes.Both,
+                            Colour = Color4.White,
+                            BlendingMode = BlendingMode.Additive,
+                            Alpha = 0,
+                            AlwaysPresent = true
+                        }
+                    }
+                },
+                content = new Container
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Name = "Content",
+                    Anchor = Anchor.Centre,
+                    Origin = Anchor.Centre,
+                }
+            });
+
+            if (isStrong)
+            {
+                Size *= TaikoHitObject.STRONG_CIRCLE_DIAMETER_SCALE;
+
+                //default for symbols etc.
+                Content.Scale *= TaikoHitObject.STRONG_CIRCLE_DIAMETER_SCALE;
+            }
+        }
+
+        protected override void Update()
+        {
+            base.Update();
+
+            //we want to allow for width of content to remain mapped to the area inside us, regardless of the scale applied above.
+            Content.Width = 1 / Content.Scale.X;
+        }
+
+        private void resetEdgeEffects()
+        {
+            background.EdgeEffect = new EdgeEffect
+            {
+                Type = EdgeEffectType.Glow,
+                Colour = AccentColour,
+                Radius = KiaiMode ? 50 : 8
+            };
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/Pieces/ElongatedCirclePiece.cs

@@ -0,0 +1,41 @@
+// 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.Primitives;
+using osu.Game.Rulesets.Taiko.UI;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces
+{
+    public class ElongatedCirclePiece : CirclePiece
+    {
+        /// <summary>
+        /// As we are being used to define the absolute size of hits, we need to be given a relative reference of our containing <see cref="TaikoPlayfield"/>.
+        /// </summary>
+        public Func<float> PlayfieldLengthReference;
+
+        /// <summary>
+        /// The length of this piece as a multiple of the value returned by <see cref="PlayfieldLengthReference"/>
+        /// </summary>
+        public float Length;
+
+        public ElongatedCirclePiece(bool isStrong = false) : base(isStrong)
+        {
+        }
+
+        protected override void Update()
+        {
+            base.Update();
+
+            var padding = Content.DrawHeight * Content.Width / 2;
+
+            Content.Padding = new MarginPadding
+            {
+                Left = padding,
+                Right = padding,
+            };
+
+            Width = (PlayfieldLengthReference?.Invoke() ?? 0) * Length + DrawHeight;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/Pieces/RimHitSymbolPiece.cs

@@ -0,0 +1,36 @@
+// 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.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
+using OpenTK;
+using OpenTK.Graphics;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces
+{
+    /// <summary>
+    /// The symbol used for rim hit pieces.
+    /// </summary>
+    public class RimHitSymbolPiece : CircularContainer
+    {
+        public RimHitSymbolPiece()
+        {
+            Anchor = Anchor.Centre;
+            Origin = Anchor.Centre;
+            Size = new Vector2(CirclePiece.SYMBOL_SIZE);
+            BorderThickness = CirclePiece.SYMBOL_BORDER;
+            BorderColour = Color4.White;
+            Masking = true;
+            Children = new[]
+            {
+                new Box
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    Alpha = 0,
+                    AlwaysPresent = true
+                }
+            };
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/Pieces/SwellSymbolPiece.cs

@@ -0,0 +1,24 @@
+// 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.Graphics;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces
+{
+    /// <summary>
+    /// The symbol used for swell pieces.
+    /// </summary>
+    public class SwellSymbolPiece : TextAwesome
+    {
+        public SwellSymbolPiece()
+        {
+            Anchor = Anchor.Centre;
+            Origin = Anchor.Centre;
+            UseFullGlyphHeight = true;
+            TextSize = CirclePiece.SYMBOL_INNER_SIZE;
+            Icon = FontAwesome.fa_asterisk;
+            Shadow = false;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/Pieces/TaikoPiece.cs

@@ -0,0 +1,45 @@
+// 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.Containers;
+using osu.Game.Graphics;
+using OpenTK;
+using OpenTK.Graphics;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces
+{
+    public class TaikoPiece : Container, IHasAccentColour
+    {
+        private Color4 accentColour;
+        /// <summary>
+        /// The colour of the inner circle and outer glows.
+        /// </summary>
+        public virtual Color4 AccentColour
+        {
+            get { return accentColour; }
+            set
+            {
+                accentColour = value;
+            }
+        }
+
+        private bool kiaiMode;
+        /// <summary>
+        /// Whether Kiai mode effects are enabled for this circle piece.
+        /// </summary>
+        public virtual bool KiaiMode
+        {
+            get { return kiaiMode; }
+            set
+            {
+                kiaiMode = value;
+            }
+        }
+
+        public TaikoPiece()
+        {
+            //just a default
+            Size = new Vector2(TaikoHitObject.DEFAULT_CIRCLE_DIAMETER);
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Drawables/Pieces/TickPiece.cs

@@ -0,0 +1,60 @@
+// 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.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Sprites;
+using OpenTK;
+using OpenTK.Graphics;
+
+namespace osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces
+{
+    public class TickPiece : TaikoPiece
+    {
+        /// <summary>
+        /// Any tick that is not the first for a drumroll is not filled, but is instead displayed
+        /// as a hollow circle. This is what controls the border width of that circle.
+        /// </summary>
+        private const float tick_border_width = TaikoHitObject.DEFAULT_CIRCLE_DIAMETER / 16;
+
+        /// <summary>
+        /// The size of a tick.
+        /// </summary>
+        private const float tick_size = TaikoHitObject.DEFAULT_CIRCLE_DIAMETER / 4;
+
+        private bool filled;
+        public bool Filled
+        {
+            get { return filled; }
+            set
+            {
+                filled = value;
+                fillBox.Alpha = filled ? 1 : 0;
+            }
+        }
+
+        private readonly Box fillBox;
+
+        public TickPiece()
+        {
+            Size = new Vector2(tick_size);
+
+            Add(new CircularContainer
+            {
+                RelativeSizeAxes = Axes.Both,
+                Masking = true,
+                BorderThickness = tick_border_width,
+                BorderColour = Color4.White,
+                Children = new[]
+                {
+                    fillBox = new Box
+                    {
+                        RelativeSizeAxes = Axes.Both,
+                        Alpha = 0,
+                        AlwaysPresent = true
+                    }
+                }
+            });
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/DrumRoll.cs

@@ -0,0 +1,99 @@
+// 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.Objects.Types;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using osu.Game.Beatmaps.Timing;
+using osu.Game.Database;
+using osu.Game.Audio;
+
+namespace osu.Game.Rulesets.Taiko.Objects
+{
+    public class DrumRoll : TaikoHitObject, IHasEndTime
+    {
+        /// <summary>
+        /// Drum roll distance that results in a duration of 1 speed-adjusted beat length.
+        /// </summary>
+        private const float base_distance = 100;
+
+        public double EndTime => StartTime + Duration;
+
+        public double Duration { get; set; }
+
+        /// <summary>
+        /// Numer of ticks per beat length.
+        /// </summary>
+        public int TickRate = 1;
+
+        /// <summary>
+        /// Number of drum roll ticks required for a "Good" hit.
+        /// </summary>
+        public double RequiredGoodHits { get; protected set; }
+
+        /// <summary>
+        /// Number of drum roll ticks required for a "Great" hit.
+        /// </summary>
+        public double RequiredGreatHits { get; protected set; }
+
+        /// <summary>
+        /// Total number of drum roll ticks.
+        /// </summary>
+        public int TotalTicks => Ticks.Count();
+
+        /// <summary>
+        /// Initializes the drum roll ticks if not initialized and returns them.
+        /// </summary>
+        public IEnumerable<DrumRollTick> Ticks => ticks ?? (ticks = createTicks());
+
+        private List<DrumRollTick> ticks;
+
+        /// <summary>
+        /// The length (in milliseconds) between ticks of this drumroll.
+        /// <para>Half of this value is the hit window of the ticks.</para>
+        /// </summary>
+        private double tickSpacing = 100;
+
+        public override void ApplyDefaults(TimingInfo timing, BeatmapDifficulty difficulty)
+        {
+            base.ApplyDefaults(timing, difficulty);
+
+            tickSpacing = timing.BeatLengthAt(StartTime) / TickRate;
+
+            RequiredGoodHits = TotalTicks * Math.Min(0.15, 0.05 + 0.10 / 6 * difficulty.OverallDifficulty);
+            RequiredGreatHits = TotalTicks * Math.Min(0.30, 0.10 + 0.20 / 6 * difficulty.OverallDifficulty);
+        }
+
+        private List<DrumRollTick> createTicks()
+        {
+            var ret = new List<DrumRollTick>();
+
+            if (tickSpacing == 0)
+                return ret;
+
+            bool first = true;
+            for (double t = StartTime; t < EndTime + tickSpacing / 2; t += tickSpacing)
+            {
+                ret.Add(new DrumRollTick
+                {
+                    FirstTick = first,
+                    ScrollTime = ScrollTime,
+                    TickSpacing = tickSpacing,
+                    StartTime = t,
+                    IsStrong = IsStrong,
+                    Samples = Samples.Select(s => new SampleInfo
+                    {
+                        Bank = s.Bank,
+                        Name = @"slidertick",
+                        Volume = s.Volume
+                    }).ToList()
+                });
+
+                first = false;
+            }
+
+            return ret;
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/DrumRollTick.cs

@@ -0,0 +1,24 @@
+// 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.Taiko.Objects
+{
+    public class DrumRollTick : TaikoHitObject
+    {
+        /// <summary>
+        /// Whether this is the first (initial) tick of the slider.
+        /// </summary>
+        public bool FirstTick;
+
+        /// <summary>
+        /// The length (in milliseconds) between this tick and the next.
+        /// <para>Half of this value is the hit window of the tick.</para>
+        /// </summary>
+        public double TickSpacing;
+
+        /// <summary>
+        /// The time allowed to hit this tick.
+        /// </summary>
+        public double HitWindow => TickSpacing / 2;
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Hit.cs

@@ -0,0 +1,35 @@
+// 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.Timing;
+using osu.Game.Database;
+
+namespace osu.Game.Rulesets.Taiko.Objects
+{
+    public class Hit : TaikoHitObject
+    {
+        /// <summary>
+        /// The hit window that results in a "GREAT" hit.
+        /// </summary>
+        public double HitWindowGreat = 35;
+
+        /// <summary>
+        /// The hit window that results in a "GOOD" hit.
+        /// </summary>
+        public double HitWindowGood = 80;
+
+        /// <summary>
+        /// The hit window that results in a "MISS".
+        /// </summary>
+        public double HitWindowMiss = 95;
+
+        public override void ApplyDefaults(TimingInfo timing, BeatmapDifficulty difficulty)
+        {
+            base.ApplyDefaults(timing, difficulty);
+
+            HitWindowGreat = BeatmapDifficulty.DifficultyRange(difficulty.OverallDifficulty, 50, 35, 20);
+            HitWindowGood = BeatmapDifficulty.DifficultyRange(difficulty.OverallDifficulty, 120, 80, 50);
+            HitWindowMiss = BeatmapDifficulty.DifficultyRange(difficulty.OverallDifficulty, 135, 95, 70);
+        }
+    }
+}

osu.Game.Rulesets.Taiko/Objects/RimHit.cs

@@ -0,0 +1,9 @@
+// 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.Taiko.Objects
+{
+    public class RimHit : Hit
+    {
+    }
+}

osu.Game.Rulesets.Taiko/Objects/Swell.cs

@@ -0,0 +1,19 @@
+// 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.Objects.Types;
+
+namespace osu.Game.Rulesets.Taiko.Objects
+{
+    public class Swell : TaikoHitObject, IHasEndTime
+    {
+        public double EndTime => StartTime + Duration;
+
+        public double Duration { get; set; }
+
+        /// <summary>
+        /// The number of hits required to complete the swell successfully.
+        /// </summary>
+        public int RequiredHits = 10;
+    }
+}

osu.Game.Rulesets.Taiko/Objects/TaikoHitObject.cs

@@ -0,0 +1,67 @@
+// 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.Timing;
+using osu.Game.Database;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Taiko.UI;
+
+namespace osu.Game.Rulesets.Taiko.Objects
+{
+    public abstract class TaikoHitObject : HitObject
+    {
+        /// <summary>
+        /// Diameter of a circle relative to the size of the <see cref="TaikoPlayfield"/>.
+        /// </summary>
+        public const float PLAYFIELD_RELATIVE_DIAMETER = 0.5f;
+
+        /// <summary>
+        /// Scale multiplier for a strong circle.
+        /// </summary>
+        public const float STRONG_CIRCLE_DIAMETER_SCALE = 1.5f;
+
+        /// <summary>
+        /// Default circle diameter.
+        /// </summary>
+        public const float DEFAULT_CIRCLE_DIAMETER = TaikoPlayfield.DEFAULT_PLAYFIELD_HEIGHT * PLAYFIELD_RELATIVE_DIAMETER;
+
+        /// <summary>
+        /// Default strong circle diameter.
+        /// </summary>
+        public const float DEFAULT_STRONG_CIRCLE_DIAMETER = DEFAULT_CIRCLE_DIAMETER * STRONG_CIRCLE_DIAMETER_SCALE;
+
+        /// <summary>
+        /// The time taken from the initial (off-screen) spawn position to the centre of the hit target for a <see cref="ControlPoint.BeatLength"/> of 1000ms.
+        /// </summary>
+        private const double scroll_time = 6000;
+
+        /// <summary>
+        /// Our adjusted <see cref="scroll_time"/> taking into consideration local <see cref="ControlPoint.BeatLength"/> and other speed multipliers.
+        /// </summary>
+        public double ScrollTime;
+
+        /// <summary>
+        /// Whether this HitObject is a "strong" type.
+        /// Strong hit objects give more points for hitting the hit object with both keys.
+        /// </summary>
+        public bool IsStrong;
+
+        /// <summary>
+        /// Whether this HitObject is in Kiai time.
+        /// </summary>
+        public bool Kiai { get; protected set; }
+
+        public override void ApplyDefaults(TimingInfo timing, BeatmapDifficulty difficulty)
+        {
+            base.ApplyDefaults(timing, difficulty);
+
+            ScrollTime = scroll_time * (timing.BeatLengthAt(StartTime) * timing.SpeedMultiplierAt(StartTime) / 1000) / difficulty.SliderMultiplier;
+
+            ControlPoint overridePoint;
+            Kiai = timing.TimingPointAt(StartTime, out overridePoint).KiaiMode;
+
+            if (overridePoint != null)
+                Kiai |= overridePoint.KiaiMode;
+        }
+    }
+}