Merge pull request #6 from winnerspiros/fix-catch-time-delta-truncation-11917992746850541583

Fix integer truncation in CatchBeatmapProcessor time delta calculation

Author: winnerspiros

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

@@ -0,0 +1,58 @@
+// 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.Rulesets.Catch.Beatmaps;
+using osu.Game.Rulesets.Catch.Objects;
+
+namespace osu.Game.Rulesets.Catch.Tests
+{
+    [TestFixture]
+    public class CatchBeatmapProcessorTest
+    {
+        [Test]
+        public void TestHardRockOffsetDoublePrecision()
+        {
+            // Setup a beatmap with two fruits that will trigger the logic difference.
+            // We need a time difference that has a fractional part.
+            // And we need HardRock enabled.
+
+            // lastPosition = 100, lastStartTime = 1000.
+            // offsetPosition = 133.2, startTime = 1100.5.
+
+            // positionDiff = 33.2.
+            // timeDiff (int) = 100.
+            // timeDiff (double) = 100.5.
+
+            // positionDiff < timeDiff / 3
+            // 33.2 < 33 (False)
+            // 33.2 < 33.5 (True)
+
+            var beatmap = new Beatmap<CatchHitObject>
+            {
+                HitObjects = new List<CatchHitObject>
+                {
+                    new Fruit { StartTime = 1000, X = 100 },
+                    new Fruit { StartTime = 1000 + 100.5, X = 100 + 33.2f }
+                }
+            };
+
+            var processor = new CatchBeatmapProcessor(beatmap)
+            {
+                HardRockOffsets = true
+            };
+
+            processor.ApplyPositionOffsets(beatmap);
+
+            var secondObj = beatmap.HitObjects[1];
+
+            // If bug is present (int truncation), condition is false, XOffset is 0.
+            // If fixed (double), condition is true, XOffset is 33.2 (approx).
+
+            Assert.That(secondObj.XOffset, Is.Not.EqualTo(0).Within(0.001));
+            Assert.That(secondObj.XOffset, Is.EqualTo(33.2f).Within(0.001));
+        }
+    }
+}

osu.Game.Rulesets.Catch.Tests/Resources/Testing/Beatmaps/1431386-expected-conversion.json

@@ -132,8 +132,8 @@ private static void applyHardRockOffset(CatchHitObject hitObject, ref float? las
 
             float positionDiff = offsetPosition - lastPosition.Value;
 
-            // Todo: BUG!! Stable calculated time deltas as ints, which affects randomisation. This should be changed to a double.
-            int timeDiff = (int)(startTime - lastStartTime);
+            // Stable calculated time deltas as ints, which affects randomisation. This has been changed to a double to fix the issue.
+            double timeDiff = startTime - lastStartTime;
 
             if (timeDiff > 1000)
             {