Add legacy slider offsets

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

@@ -26,6 +26,7 @@ namespace osu.Game.Rulesets.Catch.Beatmaps
             var positionData = obj as IHasXPosition;
             var comboData = obj as IHasCombo;
             var endTime = obj as IHasEndTime;
+            var legacyOffset = obj as IHasLegacyLastTickOffset;
 
             if (curveData != null)
             {
@@ -39,7 +40,8 @@ namespace osu.Game.Rulesets.Catch.Beatmaps
                     RepeatSamples = curveData.RepeatSamples,
                     RepeatCount = curveData.RepeatCount,
                     X = (positionData?.X ?? 0) / CatchPlayfield.BASE_WIDTH,
-                    NewCombo = comboData?.NewCombo ?? false
+                    NewCombo = comboData?.NewCombo ?? false,
+                    LegacyLastTickOffset = legacyOffset?.LegacyLastTickOffset ?? 0
                 };
             }
             else if (endTime != null)

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

@@ -77,6 +77,13 @@ namespace osu.Game.Rulesets.Catch.Objects
 
                     double time = spanStartTime + timeProgress * spanDuration;
 
+                    if (LegacyLastTickOffset != null)
+                    {
+                        // If we're the last tick, apply the legacy offset
+                        if (span == this.SpanCount() - 1 && d + tickDistance > length)
+                            time = Math.Max(StartTime + Duration / 2, time - LegacyLastTickOffset.Value);
+                    }
+
                     double tinyTickInterval = time - lastDropletTime;
                     while (tinyTickInterval > 100)
                         tinyTickInterval /= 2;
@@ -152,5 +159,7 @@ namespace osu.Game.Rulesets.Catch.Objects
             get { return Curve.CurveType; }
             set { Curve.CurveType = value; }
         }
+
+        public double? LegacyLastTickOffset { get; set; }
     }
 }

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

@@ -27,6 +27,7 @@ namespace osu.Game.Rulesets.Osu.Beatmaps
             var endTimeData = original as IHasEndTime;
             var positionData = original as IHasPosition;
             var comboData = original as IHasCombo;
+            var legacyOffset = original as IHasLegacyLastTickOffset;
 
             if (curveData != null)
             {
@@ -40,7 +41,8 @@ namespace osu.Game.Rulesets.Osu.Beatmaps
                     RepeatSamples = curveData.RepeatSamples,
                     RepeatCount = curveData.RepeatCount,
                     Position = positionData?.Position ?? Vector2.Zero,
-                    NewCombo = comboData?.NewCombo ?? false
+                    NewCombo = comboData?.NewCombo ?? false,
+                    LegacyLastTickOffset = legacyOffset?.LegacyLastTickOffset
                 };
             }
             else if (endTimeData != null)

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

@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using OpenTK;
 using osu.Game.Rulesets.Objects.Types;
 using System.Collections.Generic;
@@ -45,6 +46,8 @@ namespace osu.Game.Rulesets.Osu.Objects
             set { Curve.Distance = value; }
         }
 
+        public double? LegacyLastTickOffset { get; set; }
+
         /// <summary>
         /// The position of the cursor at the point of completion of this <see cref="Slider"/> if it was hit
         /// with as few movements as possible. This is set and used by difficulty calculation.
@@ -91,6 +94,13 @@ namespace osu.Game.Rulesets.Osu.Objects
             createSliderEnds();
             createTicks();
             createRepeatPoints();
+
+            if (LegacyLastTickOffset != null)
+            {
+                var lastObject = NestedHitObjects.Last();
+                if (!(lastObject is SliderCircle))
+                    lastObject.StartTime = Math.Max(StartTime + Duration / 2, lastObject.StartTime - LegacyLastTickOffset.Value);
+            }
         }
 
         private void createSliderEnds()

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

@@ -10,7 +10,7 @@ using osu.Game.Beatmaps.ControlPoints;
 
 namespace osu.Game.Rulesets.Objects.Legacy
 {
-    internal abstract class ConvertSlider : HitObject, IHasCurve
+    internal abstract class ConvertSlider : HitObject, IHasCurve, IHasLegacyLastTickOffset
     {
         /// <summary>
         /// Scoring distance with a speed-adjusted beat length of 1 second.
@@ -45,5 +45,7 @@ namespace osu.Game.Rulesets.Objects.Legacy
 
             Velocity = scoringDistance / timingPoint.BeatLength;
         }
+
+        public double LegacyLastTickOffset => 36;
     }
 }

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

@@ -0,0 +1,14 @@
+// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+namespace osu.Game.Rulesets.Objects.Types
+{
+    /// <summary>
+    /// A type of <see cref="HitObject"/> which may require the last tick to be offset.
+    /// This is specific to osu!stable conversion, and should not be used elsewhere.
+    /// </summary>
+    public interface IHasLegacyLastTickOffset
+    {
+        double LegacyLastTickOffset { get; }
+    }
+}