From 58eb7f6fe174ba72f06304d0334b0668dde14c74 Mon Sep 17 00:00:00 2001
From: OliBomby <olivierschipper@gmail.com>
Date: Sun, 14 Jul 2024 16:58:05 +0200
Subject: [PATCH] fix rotated scale bounds again

---
 .../Edit/OsuSelectionScaleHandler.cs          | 31 ++++++++++--
 osu.Game/Utils/GeometryUtils.cs               | 49 ++++++++++++++++++-
 2 files changed, 73 insertions(+), 7 deletions(-)

diff --git a/osu.Game.Rulesets.Osu/Edit/OsuSelectionScaleHandler.cs b/osu.Game.Rulesets.Osu/Edit/OsuSelectionScaleHandler.cs
index 8b87246456..56c3ba9315 100644
--- a/osu.Game.Rulesets.Osu/Edit/OsuSelectionScaleHandler.cs
+++ b/osu.Game.Rulesets.Osu/Edit/OsuSelectionScaleHandler.cs
@@ -69,6 +69,7 @@ namespace osu.Game.Rulesets.Osu.Edit
 
         private Dictionary<OsuHitObject, OriginalHitObjectState>? objectsInScale;
         private Vector2? defaultOrigin;
+        private List<Vector2>? originalConvexHull;
 
         public override void Begin()
         {
@@ -84,6 +85,9 @@ namespace osu.Game.Rulesets.Osu.Edit
                 ? GeometryUtils.GetSurroundingQuad(slider.Path.ControlPoints.Select(p => slider.Position + p.Position))
                 : GeometryUtils.GetSurroundingQuad(objectsInScale.Keys);
             defaultOrigin = OriginalSurroundingQuad.Value.Centre;
+            originalConvexHull = objectsInScale.Count == 1 && objectsInScale.First().Key is Slider slider2
+                ? GeometryUtils.GetConvexHull(slider2.Path.ControlPoints.Select(p => slider2.Position + p.Position))
+                : GeometryUtils.GetConvexHull(objectsInScale.Keys);
         }
 
         public override void Update(Vector2 scale, Vector2? origin = null, Axes adjustAxis = Axes.Both, float axisRotation = 0)
@@ -211,12 +215,31 @@ namespace osu.Game.Rulesets.Osu.Edit
             if (objectsInScale.Count == 1 && objectsInScale.First().Key is Slider slider)
                 origin = slider.Position;
 
+            float cos = MathF.Cos(float.DegreesToRadians(-axisRotation));
+            float sin = MathF.Sin(float.DegreesToRadians(-axisRotation));
             scale = clampScaleToAdjustAxis(scale, adjustAxis);
             Vector2 actualOrigin = origin ?? defaultOrigin.Value;
-            var selectionQuad = OriginalSurroundingQuad.Value;
+            IEnumerable<Vector2> points;
 
-            scale = clampToBound(scale, selectionQuad.BottomRight, OsuPlayfield.BASE_SIZE);
-            scale = clampToBound(scale, selectionQuad.TopLeft, Vector2.Zero);
+            if (axisRotation == 0)
+            {
+                var selectionQuad = OriginalSurroundingQuad.Value;
+                points = new[]
+                {
+                    selectionQuad.TopLeft,
+                    selectionQuad.TopRight,
+                    selectionQuad.BottomLeft,
+                    selectionQuad.BottomRight
+                };
+            }
+            else
+                points = originalConvexHull!;
+
+            foreach (var point in points)
+            {
+                scale = clampToBound(scale, point, Vector2.Zero);
+                scale = clampToBound(scale, point, OsuPlayfield.BASE_SIZE);
+            }
 
             return Vector2.ComponentMax(scale, new Vector2(Precision.FLOAT_EPSILON));
 
@@ -226,8 +249,6 @@ namespace osu.Game.Rulesets.Osu.Edit
             {
                 p -= actualOrigin;
                 bound -= actualOrigin;
-                float cos = MathF.Cos(float.DegreesToRadians(-axisRotation));
-                float sin = MathF.Sin(float.DegreesToRadians(-axisRotation));
                 var a = new Vector2(cos * cos * p.X - sin * cos * p.Y, -sin * cos * p.X + sin * sin * p.Y);
                 var b = new Vector2(sin * sin * p.X + sin * cos * p.Y, sin * cos * p.X + cos * cos * p.Y);
 
diff --git a/osu.Game/Utils/GeometryUtils.cs b/osu.Game/Utils/GeometryUtils.cs
index f6e7e81007..5a8ca9722e 100644
--- a/osu.Game/Utils/GeometryUtils.cs
+++ b/osu.Game/Utils/GeometryUtils.cs
@@ -138,7 +138,52 @@ namespace osu.Game.Utils
         /// </summary>
         /// <param name="hitObjects">The hit objects to calculate a quad for.</param>
         public static Quad GetSurroundingQuad(IEnumerable<IHasPosition> hitObjects) =>
-            GetSurroundingQuad(hitObjects.SelectMany(h =>
+            GetSurroundingQuad(enumerateStartAndEndPositions(hitObjects));
+
+        /// <summary>
+        /// Returns the points that make up the convex hull of the provided points.
+        /// </summary>
+        /// <param name="points">The points to calculate a convex hull.</param>
+        public static List<Vector2> GetConvexHull(IEnumerable<Vector2> points)
+        {
+            List<Vector2> p = points.ToList();
+
+            if (p.Count <= 1)
+                return p;
+
+            int n = p.Count, k = 0;
+            List<Vector2> hull = new List<Vector2>(new Vector2[2 * n]);
+
+            p.Sort((a, b) => a.X == b.X ? a.Y.CompareTo(b.Y) : a.X.CompareTo(b.X));
+
+            // Build lower hull
+            for (int i = 0; i < n; ++i)
+            {
+                while (k >= 2 && cross(hull[k - 2], hull[k - 1], p[i]) <= 0)
+                    k--;
+                hull[k] = p[i];
+                k++;
+            }
+
+            // Build upper hull
+            for (int i = n - 2, t = k + 1; i >= 0; i--)
+            {
+                while (k >= t && cross(hull[k - 2], hull[k - 1], p[i]) <= 0)
+                    k--;
+                hull[k] = p[i];
+                k++;
+            }
+
+            return hull.Take(k - 1).ToList();
+
+            float cross(Vector2 o, Vector2 a, Vector2 b) => (a.X - o.X) * (b.Y - o.Y) - (a.Y - o.Y) * (b.X - o.X);
+        }
+
+        public static List<Vector2> GetConvexHull(IEnumerable<IHasPosition> hitObjects) =>
+            GetConvexHull(enumerateStartAndEndPositions(hitObjects));
+
+        private static IEnumerable<Vector2> enumerateStartAndEndPositions(IEnumerable<IHasPosition> hitObjects) =>
+            hitObjects.SelectMany(h =>
             {
                 if (h is IHasPath path)
                 {
@@ -151,6 +196,6 @@ namespace osu.Game.Utils
                 }
 
                 return new[] { h.Position };
-            }));
+            });
     }
 }