Add tests for BeatDivisorFinder

osu.Game.Tests/NonVisual/BeatDivisorFinder.cs

@@ -0,0 +1,116 @@
+// 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 System.Collections.Generic;
+using NUnit.Framework;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Rulesets.Objects;
+
+namespace osu.Game.Tests.NonVisual
+{
+    public class BeatDivisorFinderTest
+    {
+        [Test]
+        public void TestFindDivisor()
+        {
+            const int beatLength = 1000;
+
+            var beatmap = new Beatmap
+            {
+                HitObjects = new List<HitObject>
+                {
+                    new HitObject { StartTime = -beatLength / 3 },
+                    new HitObject { StartTime = 0 },
+                    new HitObject { StartTime = beatLength / 16 },
+                    new HitObject { StartTime = beatLength / 12 },
+                    new HitObject { StartTime = beatLength / 8 },
+                    new HitObject { StartTime = beatLength / 6 },
+                    new HitObject { StartTime = beatLength / 4 },
+                    new HitObject { StartTime = beatLength / 3 },
+                    new HitObject { StartTime = beatLength / 2 },
+                    new HitObject { StartTime = beatLength },
+                    new HitObject { StartTime = beatLength + beatLength / 7 }
+                },
+                ControlPointInfo = new ControlPointInfo()
+            };
+
+            beatmap.ControlPointInfo.Add(0, new TimingControlPoint()
+                {
+                    TimeSignature = Game.Beatmaps.Timing.TimeSignatures.SimpleQuadruple,
+                    BeatLength = beatLength
+                });
+
+            var beatDivisorFinder = new BeatDivisorFinder(beatmap);
+
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[0]), 3);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[1]), 1);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[2]), 16);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[3]), 12);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[4]), 8);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[5]), 6);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[6]), 4);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[7]), 3);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[8]), 2);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[9]), 1);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[10]), 0);
+        }
+
+        [Test]
+        public void TestFindDivisorWithTempoChanges()
+        {
+            const int firstBeatLength = 1000;
+            const int secondBeatLength = 700;
+            const int thirdBeatLength = 200;
+
+            const int firstBeatLengthStart = 0;
+            const int secondBeatLengthStart = 1000;
+            const int thirdBeatLengthStart = 2000;
+
+            var beatmap = new Beatmap
+            {
+                HitObjects = new List<HitObject>
+                {
+                    new HitObject { StartTime = firstBeatLengthStart },
+                    new HitObject { StartTime = firstBeatLengthStart + firstBeatLength / 2 },
+                    new HitObject { StartTime = secondBeatLengthStart },
+                    new HitObject { StartTime = secondBeatLengthStart + secondBeatLength / 2 },
+                    new HitObject { StartTime = thirdBeatLengthStart },
+                    new HitObject { StartTime = thirdBeatLengthStart + thirdBeatLength / 2 },
+                },
+                ControlPointInfo = new ControlPointInfo()
+            };
+
+            var firstTimingControlPoint = new TimingControlPoint()
+            {
+                TimeSignature = Game.Beatmaps.Timing.TimeSignatures.SimpleQuadruple,
+                BeatLength = firstBeatLength
+            };
+            
+            var secondTimingControlPoint = new TimingControlPoint()
+            {
+                TimeSignature = Game.Beatmaps.Timing.TimeSignatures.SimpleQuadruple,
+                BeatLength = secondBeatLength
+            };
+            
+            var thirdTimingControlPoint = new TimingControlPoint()
+            {
+                TimeSignature = Game.Beatmaps.Timing.TimeSignatures.SimpleQuadruple,
+                BeatLength = thirdBeatLength
+            };
+
+            beatmap.ControlPointInfo.Add(firstBeatLengthStart, firstTimingControlPoint);
+            beatmap.ControlPointInfo.Add(secondBeatLengthStart, secondTimingControlPoint);
+            beatmap.ControlPointInfo.Add(thirdBeatLengthStart, thirdTimingControlPoint);
+
+            var beatDivisorFinder = new BeatDivisorFinder(beatmap);
+
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[0]), 1);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[1]), 2);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[2]), 1);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[3]), 2);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[4]), 1);
+            Assert.AreEqual(beatDivisorFinder.FindDivisor(beatmap.HitObjects[5]), 2);
+        }
+    }
+}

osu.Game/Rulesets/Objects/BeatDivisorFinder.cs

@@ -27,12 +27,13 @@ namespace osu.Game.Rulesets.Objects
 
         /// <summary>
         /// Finds the lowest beat divisor that the given <see cref="HitObject"/> aligns to.
+        /// Returns 0 if it does not align to any divisor.
         /// </summary>
         /// <param name="hitObject">The <see cref="HitObject"/> to evaluate.</param>
         public int FindDivisor(HitObject hitObject)
         {
             TimingControlPoint currentTimingPoint = beatmap.ControlPointInfo.TimingPointAt(hitObject.StartTime);
-            double snapResult = (hitObject.StartTime - currentTimingPoint.Time) % (currentTimingPoint.BeatLength * 4);
+            double snapResult = hitObject.StartTime - currentTimingPoint.Time;
 
             foreach (var divisor in BindableBeatDivisor.VALID_DIVISORS)
             {