Merge pull request #24527 from Pasi4K5/fix-slider-reversing

Fix sliders being reversed incorrectly in the editor

osu.Game.Rulesets.Osu.Tests/Editor/TestSceneSliderReversal.cs

@@ -0,0 +1,110 @@
+// 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.Linq;
+using NUnit.Framework;
+using osu.Framework.Utils;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Types;
+using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Rulesets.Osu.UI;
+using osu.Game.Tests.Beatmaps;
+using osuTK;
+using osuTK.Input;
+
+namespace osu.Game.Rulesets.Osu.Tests.Editor
+{
+    public partial class TestSceneSliderReversal : TestSceneOsuEditor
+    {
+        protected override IBeatmap CreateBeatmap(RulesetInfo ruleset) => new TestBeatmap(Ruleset.Value, false);
+
+        private readonly PathControlPoint[][] paths =
+        {
+            createPathSegment(
+                PathType.PerfectCurve,
+                new Vector2(200, -50),
+                new Vector2(250, 0)
+            ),
+            createPathSegment(
+                PathType.Linear,
+                new Vector2(100, 0),
+                new Vector2(100, 100)
+            )
+        };
+
+        private static PathControlPoint[] createPathSegment(PathType type, params Vector2[] positions)
+        {
+            return positions.Select(p => new PathControlPoint
+            {
+                Position = p
+            }).Prepend(new PathControlPoint
+            {
+                Type = type
+            }).ToArray();
+        }
+
+        private Slider selectedSlider => (Slider)EditorBeatmap.SelectedHitObjects[0];
+
+        [TestCase(0, 250)]
+        [TestCase(0, 200)]
+        [TestCase(1, 120)]
+        [TestCase(1, 80)]
+        public void TestSliderReversal(int pathIndex, double length)
+        {
+            var controlPoints = paths[pathIndex];
+
+            Vector2 oldStartPos = default;
+            Vector2 oldEndPos = default;
+            double oldDistance = default;
+            var oldControlPointTypes = controlPoints.Select(p => p.Type);
+
+            AddStep("Add slider", () =>
+            {
+                var slider = new Slider
+                {
+                    Position = new Vector2(OsuPlayfield.BASE_SIZE.X / 2, OsuPlayfield.BASE_SIZE.Y / 2),
+                    Path = new SliderPath(controlPoints)
+                    {
+                        ExpectedDistance = { Value = length }
+                    }
+                };
+
+                EditorBeatmap.Add(slider);
+
+                oldStartPos = slider.Position;
+                oldEndPos = slider.EndPosition;
+                oldDistance = slider.Path.Distance;
+            });
+
+            AddStep("Select slider", () =>
+            {
+                var slider = (Slider)EditorBeatmap.HitObjects[0];
+                EditorBeatmap.SelectedHitObjects.Add(slider);
+            });
+
+            AddStep("Reverse slider", () =>
+            {
+                InputManager.PressKey(Key.LControl);
+                InputManager.Key(Key.G);
+                InputManager.ReleaseKey(Key.LControl);
+            });
+
+            AddAssert("Slider has correct length", () =>
+                Precision.AlmostEquals(selectedSlider.Path.Distance, oldDistance));
+
+            AddAssert("Slider has correct start position", () =>
+                Vector2.Distance(selectedSlider.Position, oldEndPos) < 1);
+
+            AddAssert("Slider has correct end position", () =>
+                Vector2.Distance(selectedSlider.EndPosition, oldStartPos) < 1);
+
+            AddAssert("Control points have correct types", () =>
+            {
+                var newControlPointTypes = selectedSlider.Path.ControlPoints.Select(p => p.Type).ToArray();
+
+                return oldControlPointTypes.Take(newControlPointTypes.Length).SequenceEqual(newControlPointTypes);
+            });
+        }
+    }
+}

osu.Game/Rulesets/Objects/SliderPathExtensions.cs

@@ -1,6 +1,7 @@
 // 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 System.Linq;
 using osu.Game.Rulesets.Edit;
 using osu.Game.Rulesets.Objects.Types;
@@ -25,6 +26,53 @@ namespace osu.Game.Rulesets.Objects
         /// <param name="sliderPath">The <see cref="SliderPath"/>.</param>
         /// <param name="positionalOffset">The positional offset of the resulting path. It should be added to the start position of this path.</param>
         public static void Reverse(this SliderPath sliderPath, out Vector2 positionalOffset)
+        {
+            var controlPoints = sliderPath.ControlPoints;
+
+            var inheritedLinearPoints = controlPoints.Where(p => sliderPath.PointsInSegment(p)[0].Type == PathType.Linear && p.Type is null).ToList();
+
+            // Inherited points after a linear point, as well as the first control point if it inherited,
+            // should be treated as linear points, so their types are temporarily changed to linear.
+            inheritedLinearPoints.ForEach(p => p.Type = PathType.Linear);
+
+            double[] segmentEnds = sliderPath.GetSegmentEnds().ToArray();
+
+            // Remove segments after the end of the slider.
+            for (int numSegmentsToRemove = segmentEnds.Count(se => se >= 1) - 1; numSegmentsToRemove > 0 && controlPoints.Count > 0;)
+            {
+                if (controlPoints.Last().Type is not null)
+                {
+                    numSegmentsToRemove--;
+                    segmentEnds = segmentEnds[..^1];
+                }
+
+                controlPoints.RemoveAt(controlPoints.Count - 1);
+            }
+
+            // Restore original control point types.
+            inheritedLinearPoints.ForEach(p => p.Type = null);
+
+            // Recalculate middle perfect curve control points at the end of the slider path.
+            if (controlPoints.Count >= 3 && controlPoints[^3].Type == PathType.PerfectCurve && controlPoints[^2].Type is null && segmentEnds.Any())
+            {
+                double lastSegmentStart = segmentEnds.Length > 1 ? segmentEnds[^2] : 0;
+                double lastSegmentEnd = segmentEnds[^1];
+
+                var circleArcPath = new List<Vector2>();
+                sliderPath.GetPathToProgress(circleArcPath, lastSegmentStart / lastSegmentEnd, 1);
+
+                controlPoints[^2].Position = circleArcPath[circleArcPath.Count / 2];
+            }
+
+            sliderPath.reverseControlPoints(out positionalOffset);
+        }
+
+        /// <summary>
+        /// Reverses the order of the provided <see cref="SliderPath"/>'s <see cref="PathControlPoint"/>s.
+        /// </summary>
+        /// <param name="sliderPath">The <see cref="SliderPath"/>.</param>
+        /// <param name="positionalOffset">The positional offset of the resulting path. It should be added to the start position of this path.</param>
+        private static void reverseControlPoints(this SliderPath sliderPath, out Vector2 positionalOffset)
         {
             var points = sliderPath.ControlPoints.ToArray();
             positionalOffset = sliderPath.PositionAt(1);