From 33c52ba30fa9ef9c3e02214aec0d9e89da87712a Mon Sep 17 00:00:00 2001
From: smoogipoo <smoogipoo@smgi.me>
Date: Tue, 23 Jan 2018 13:58:43 +0900
Subject: [PATCH] Fix off-by-ones in RepeatPoint code

---
 .../Objects/Drawables/DrawableRepeatPoint.cs         |  2 +-
 .../Objects/Drawables/DrawableSlider.cs              | 12 ++++++------
 osu.Game.Rulesets.Osu/Objects/Slider.cs              |  8 ++++----
 osu.Game.Rulesets.Osu/Objects/SliderTick.cs          |  2 +-
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableRepeatPoint.cs b/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableRepeatPoint.cs
index 28ff4b4cdf..6cf353eaf2 100644
--- a/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableRepeatPoint.cs
+++ b/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableRepeatPoint.cs
@@ -72,6 +72,6 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables
             }
         }
 
-        public void UpdateSnakingPosition(Vector2 start, Vector2 end) => Position = repeatPoint.RepeatIndex % 2 == 1 ? end : start;
+        public void UpdateSnakingPosition(Vector2 start, Vector2 end) => Position = repeatPoint.RepeatIndex % 2 == 0 ? end : start;
     }
 }
diff --git a/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableSlider.cs b/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableSlider.cs
index fae56dcce2..6f3bb34a89 100644
--- a/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableSlider.cs
+++ b/osu.Game.Rulesets.Osu/Objects/Drawables/DrawableSlider.cs
@@ -73,12 +73,12 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables
 
             AddNested(InitialCircle);
 
-            var repeatDuration = s.Curve.Distance / s.Velocity;
+            var spanDuration = s.Curve.Distance / s.Velocity;
             foreach (var tick in s.NestedHitObjects.OfType<SliderTick>())
             {
-                var repeatStartTime = s.StartTime + tick.RepeatIndex * repeatDuration;
-                var fadeInTime = repeatStartTime + (tick.StartTime - repeatStartTime) / 2 - (tick.RepeatIndex == 0 ? HitObject.TimeFadein : HitObject.TimeFadein / 2);
-                var fadeOutTime = repeatStartTime + repeatDuration;
+                var spanStartTime = s.StartTime + tick.SpanIndex * spanDuration;
+                var fadeInTime = spanStartTime + (tick.StartTime - spanStartTime) / 2 - (tick.SpanIndex == 0 ? HitObject.TimeFadein : HitObject.TimeFadein / 2);
+                var fadeOutTime = spanStartTime + spanDuration;
 
                 var drawableTick = new DrawableSliderTick(tick)
                 {
@@ -93,9 +93,9 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables
 
             foreach (var repeatPoint in s.NestedHitObjects.OfType<RepeatPoint>())
             {
-                var repeatStartTime = s.StartTime + repeatPoint.RepeatIndex * repeatDuration;
+                var repeatStartTime = s.StartTime + (repeatPoint.RepeatIndex + 1) * spanDuration;
                 var fadeInTime = repeatStartTime + (repeatPoint.StartTime - repeatStartTime) / 2 - (repeatPoint.RepeatIndex == 0 ? HitObject.TimeFadein : HitObject.TimeFadein / 2);
-                var fadeOutTime = repeatStartTime + repeatDuration;
+                var fadeOutTime = repeatStartTime + spanDuration;
 
                 var drawableRepeatPoint = new DrawableRepeatPoint(repeatPoint, this)
                 {
diff --git a/osu.Game.Rulesets.Osu/Objects/Slider.cs b/osu.Game.Rulesets.Osu/Objects/Slider.cs
index c49fbce16d..35635788f2 100644
--- a/osu.Game.Rulesets.Osu/Objects/Slider.cs
+++ b/osu.Game.Rulesets.Osu/Objects/Slider.cs
@@ -132,7 +132,7 @@ namespace osu.Game.Rulesets.Osu.Objects
 
                     AddNested(new SliderTick
                     {
-                        RepeatIndex = span,
+                        SpanIndex = span,
                         StartTime = spanStartTime + timeProgress * spanDuration,
                         Position = Curve.PositionAt(distanceProgress),
                         StackHeight = StackHeight,
@@ -148,19 +148,19 @@ namespace osu.Game.Rulesets.Osu.Objects
         {
             var repeatDuration = Distance / Velocity;
 
-            for (var repeat = 1; repeat <= RepeatCount; repeat++)
+            for (int repeatIndex = 0, repeat = 1; repeatIndex < RepeatCount; repeatIndex++, repeat++)
             {
                 var repeatStartTime = StartTime + repeat * repeatDuration;
 
                 AddNested(new RepeatPoint
                 {
-                    RepeatIndex = repeat,
+                    RepeatIndex = repeatIndex,
                     StartTime = repeatStartTime,
                     Position = Curve.PositionAt(repeat % 2),
                     StackHeight = StackHeight,
                     Scale = Scale,
                     ComboColour = ComboColour,
-                    Samples = new List<SampleInfo>(RepeatSamples[repeat])
+                    Samples = new List<SampleInfo>(RepeatSamples[repeatIndex])
                 });
             }
         }
diff --git a/osu.Game.Rulesets.Osu/Objects/SliderTick.cs b/osu.Game.Rulesets.Osu/Objects/SliderTick.cs
index e6955b48e7..5f9a978902 100644
--- a/osu.Game.Rulesets.Osu/Objects/SliderTick.cs
+++ b/osu.Game.Rulesets.Osu/Objects/SliderTick.cs
@@ -5,6 +5,6 @@ namespace osu.Game.Rulesets.Osu.Objects
 {
     public class SliderTick : OsuHitObject
     {
-        public int RepeatIndex { get; set; }
+        public int SpanIndex { get; set; }
     }
 }