Add failing test cases

osu.Game.Tests/Rulesets/Mods/ModTimeRampTest.cs

@@ -0,0 +1,82 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using NUnit.Framework;
+using osu.Framework.Audio.Track;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Osu.Objects;
+
+namespace osu.Game.Tests.Rulesets.Mods
+{
+    [TestFixture]
+    public class ModTimeRampTest
+    {
+        private const double start_time = 1000;
+        private const double duration = 9000;
+
+        private TrackVirtual track;
+        private IBeatmap beatmap;
+
+        [SetUp]
+        public void SetUp()
+        {
+            track = new TrackVirtual(20_000);
+            beatmap = new Beatmap
+            {
+                HitObjects =
+                {
+                    new Spinner
+                    {
+                        StartTime = start_time,
+                        Duration = duration
+                    }
+                }
+            };
+        }
+
+        [TestCase(0, 1)]
+        [TestCase(start_time, 1)]
+        [TestCase(start_time + duration * ModTimeRamp.FINAL_RATE_PROGRESS / 2, 1.25)]
+        [TestCase(start_time + duration * ModTimeRamp.FINAL_RATE_PROGRESS, 1.5)]
+        [TestCase(start_time + duration, 1.5)]
+        [TestCase(15000, 1.5)]
+        public void TestModWindUp(double time, double expectedRate)
+        {
+            var mod = new ModWindUp();
+            mod.ApplyToBeatmap(beatmap);
+            mod.ApplyToTrack(track);
+
+            seekTrackAndUpdateMod(mod, time);
+
+            Assert.That(mod.SpeedChange.Value, Is.EqualTo(expectedRate));
+        }
+
+        [TestCase(0, 1)]
+        [TestCase(start_time, 1)]
+        [TestCase(start_time + duration * ModTimeRamp.FINAL_RATE_PROGRESS / 2, 0.75)]
+        [TestCase(start_time + duration * ModTimeRamp.FINAL_RATE_PROGRESS, 0.5)]
+        [TestCase(start_time + duration, 0.5)]
+        [TestCase(15000, 0.5)]
+        public void TestModWindDown(double time, double expectedRate)
+        {
+            var mod = new ModWindDown
+            {
+                FinalRate = { Value = 0.5 }
+            };
+            mod.ApplyToBeatmap(beatmap);
+            mod.ApplyToTrack(track);
+
+            seekTrackAndUpdateMod(mod, time);
+
+            Assert.That(mod.SpeedChange.Value, Is.EqualTo(expectedRate));
+        }
+
+        private void seekTrackAndUpdateMod(ModTimeRamp mod, double time)
+        {
+            track.Seek(time);
+            // update the mod via a fake playfield to re-calculate the current rate.
+            mod.Update(null);
+        }
+    }
+}

osu.Game/Rulesets/Mods/ModTimeRamp.cs

@@ -19,7 +19,7 @@ namespace osu.Game.Rulesets.Mods
         /// <summary>
         /// The point in the beatmap at which the final ramping rate should be reached.
         /// </summary>
-        private const double final_rate_progress = 0.75f;
+        public const double FINAL_RATE_PROGRESS = 0.75f;
 
         [SettingSource("Initial rate", "The starting speed of the track")]
         public abstract BindableNumber<double> InitialRate { get; }
@@ -71,7 +71,7 @@ namespace osu.Game.Rulesets.Mods
             SpeedChange.SetDefault();
 
             beginRampTime = beatmap.HitObjects.FirstOrDefault()?.StartTime ?? 0;
-            finalRateTime = final_rate_progress * (lastObject?.GetEndTime() ?? 0);
+            finalRateTime = FINAL_RATE_PROGRESS * (lastObject?.GetEndTime() ?? 0);
         }
 
         public virtual void Update(Playfield playfield)