Fix legacy tick distance in JuiceStream generation

osu.Game.Rulesets.Catch.Tests/CatchBeatmapConversionTest.cs

@@ -29,6 +29,7 @@ namespace osu.Game.Rulesets.Catch.Tests
         [TestCase("basic-hyperdash")]
         [TestCase("pixel-jump")]
         [TestCase("tiny-ticks")]
+        [TestCase("v8-tick-distance")]
         public new void Test(string name, params Type[] mods) => base.Test(name, mods);
 
         protected override IEnumerable<ConvertValue> CreateConvertValue(HitObject hitObject)

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

@@ -9,6 +9,7 @@ using System.Threading;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Objects;
 using osu.Framework.Extensions.IEnumerableExtensions;
+using osu.Game.Beatmaps.Legacy;
 
 namespace osu.Game.Rulesets.Catch.Beatmaps
 {
@@ -42,6 +43,9 @@ namespace osu.Game.Rulesets.Catch.Beatmaps
                         NewCombo = comboData?.NewCombo ?? false,
                         ComboOffset = comboData?.ComboOffset ?? 0,
                         LegacyConvertedY = yPositionData?.Y ?? CatchHitObject.DEFAULT_LEGACY_CONVERT_Y,
+                        // prior to v8, speed multipliers don't adjust for how many ticks are generated over the same distance.
+                        // this results in more (or less) ticks being generated in <v8 maps for the same time duration.
+                        TickDistanceMultiplier = beatmap.BeatmapInfo.BeatmapVersion < 8 ? 1 : ((LegacyControlPointInfo)beatmap.ControlPointInfo).DifficultyPointAt(obj.StartTime).SliderVelocity,
                         SliderVelocityMultiplier = sliderVelocityData?.SliderVelocityMultiplier ?? 1
                     }.Yield();
 

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

@@ -41,6 +41,12 @@ namespace osu.Game.Rulesets.Catch.Objects
             set => SliderVelocityMultiplierBindable.Value = value;
         }
 
+        /// <summary>
+        /// An extra multiplier that affects the number of <see cref="Droplet"/>s generated by this <see cref="JuiceStream"/>.
+        /// An increase in this value increases <see cref="TickDistance"/>, which reduces the number of ticks generated.
+        /// </summary>
+        public double TickDistanceMultiplier = 1;
+
         [JsonIgnore]
         private double velocityFactor;
 
@@ -51,7 +57,7 @@ namespace osu.Game.Rulesets.Catch.Objects
         public double Velocity => velocityFactor * SliderVelocityMultiplier;
 
         [JsonIgnore]
-        public double TickDistance => tickDistanceFactor * SliderVelocityMultiplier;
+        public double TickDistance => tickDistanceFactor * TickDistanceMultiplier;
 
         /// <summary>
         /// The length of one span of this <see cref="JuiceStream"/>.

osu.Game.Rulesets.Catch/Resources/Testing/Beatmaps/v8-tick-distance-expected-conversion.json

@@ -0,0 +1,54 @@
+{
+  "Mappings": [
+    {
+      "StartTime": 81593.0,
+      "Objects": [
+        {
+          "StartTime": 81593.0,
+          "Position": 384.0,
+          "HyperDash": false
+        },
+        {
+          "StartTime": 81652.0,
+          "Position": 377.608948,
+          "HyperDash": false
+        },
+        {
+          "StartTime": 81712.0,
+          "Position": 390.3638,
+          "HyperDash": false
+        },
+        {
+          "StartTime": 81772.0,
+          "Position": 407.118683,
+          "HyperDash": false
+        },
+        {
+          "StartTime": 81832.0,
+          "Position": 433.873535,
+          "HyperDash": false
+        },
+        {
+          "StartTime": 81891.0,
+          "Position": 444.482483,
+          "HyperDash": false
+        },
+        {
+          "StartTime": 81951.0,
+          "Position": 437.237366,
+          "HyperDash": false
+        },
+        {
+          "StartTime": 82011.0,
+          "Position": 443.992218,
+          "HyperDash": false
+        },
+        {
+          "StartTime": 82107.0,
+          "Position": 459.0,
+          "HyperDash": false
+        }
+      ]
+    }
+  ]
+}

osu.Game.Rulesets.Catch/Resources/Testing/Beatmaps/v8-tick-distance.osu

@@ -0,0 +1,19 @@
+osu file format v7
+
+[General]
+StackLeniency: 0.7
+Mode: 0
+
+[Difficulty]
+HPDrainRate:5
+CircleSize:4
+OverallDifficulty:8
+SliderMultiplier:1
+SliderTickRate:1
+
+[TimingPoints]
+336,342.857142857143,4,1,0,100,1,0
+81588,-200,4,2,0,100,0,0
+
+[HitObjects]
+384,72,81593,2,12,B|464:72,1,75,4|4