From b7fca88b4fb5504af28946ca92b48045310ea46e Mon Sep 17 00:00:00 2001
From: Damnae <damnaee@gmail.com>
Date: Wed, 15 Feb 2017 18:55:49 +0100
Subject: [PATCH] Clearer slider Velocity and TickDistance calculations.

---
 osu.Game.Modes.Osu/Objects/Slider.cs | 11 +++++----
 osu.Game/Beatmaps/Beatmap.cs         | 35 ++++++++++++++++------------
 2 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/osu.Game.Modes.Osu/Objects/Slider.cs b/osu.Game.Modes.Osu/Objects/Slider.cs
index 30ad1c0180..f64d443bcc 100644
--- a/osu.Game.Modes.Osu/Objects/Slider.cs
+++ b/osu.Game.Modes.Osu/Objects/Slider.cs
@@ -4,6 +4,7 @@
 using OpenTK;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.Samples;
+using osu.Game.Beatmaps.Timing;
 using System;
 using System.Collections.Generic;
 
@@ -53,11 +54,13 @@ namespace osu.Game.Modes.Osu.Objects
 
             var baseDifficulty = beatmap.BeatmapInfo.BaseDifficulty;
 
-            var startBeatLength = beatmap.BeatLengthAt(StartTime);
-            var multipliedStartBeatLength = beatmap.BeatLengthAt(StartTime, true);
+            ControlPoint overridePoint;
+            ControlPoint timingPoint = beatmap.TimingPointAt(StartTime, out overridePoint);
+            var velocityAdjustment = overridePoint?.VelocityAdjustment ?? 1;
+            var baseVelocity = 100 * baseDifficulty.SliderMultiplier;
 
-            Velocity = 100 / multipliedStartBeatLength * baseDifficulty.SliderMultiplier;
-            TickDistance = (100 * baseDifficulty.SliderMultiplier) / baseDifficulty.SliderTickRate / (multipliedStartBeatLength / startBeatLength);
+            Velocity = baseVelocity / (timingPoint.BeatLength * velocityAdjustment);
+            TickDistance = baseVelocity / (baseDifficulty.SliderTickRate * velocityAdjustment);
         }
 
         public int RepeatCount = 1;
diff --git a/osu.Game/Beatmaps/Beatmap.cs b/osu.Game/Beatmaps/Beatmap.cs
index 0914d1a2ad..d0ce290bad 100644
--- a/osu.Game/Beatmaps/Beatmap.cs
+++ b/osu.Game/Beatmaps/Beatmap.cs
@@ -26,26 +26,31 @@ namespace osu.Game.Beatmaps
             return 60000 / BeatLengthAt(time);
         }
 
-        public double BeatLengthAt(double time, bool applyMultipliers = false)
+        public double BeatLengthAt(double time)
         {
-            int point = 0;
-            int samplePoint = 0;
+            ControlPoint overridePoint;
+            ControlPoint timingPoint = TimingPointAt(time, out overridePoint);
+            return timingPoint.BeatLength;
+        }
 
-            for (int i = 0; i < ControlPoints.Count; i++)
-                if (ControlPoints[i].Time <= time)
+        public ControlPoint TimingPointAt(double time, out ControlPoint overridePoint)
+        {
+            overridePoint = null;
+
+            ControlPoint timingPoint = null;
+            foreach (var controlPoint in ControlPoints)
+                if (controlPoint.Time <= time)
                 {
-                    if (ControlPoints[i].TimingChange)
-                        point = i;
-                    else
-                        samplePoint = i;
+                    if (controlPoint.TimingChange)
+                    {
+                        timingPoint = controlPoint;
+                        overridePoint = null;
+                    }
+                    else overridePoint = controlPoint;
                 }
+                else break;
 
-            double mult = 1;
-
-            if (applyMultipliers && samplePoint > point)
-                mult = ControlPoints[samplePoint].VelocityAdjustment;
-
-            return ControlPoints[point].BeatLength * mult;
+            return timingPoint;
         }
     }
 }