From f2edd705ea537774a662ca6121092b137bb2bb8e Mon Sep 17 00:00:00 2001
From: OliBomby <olivierschipper@gmail.com>
Date: Thu, 28 Dec 2023 18:56:49 +0100
Subject: [PATCH] add rotation to snapped position

---
 .../Components/RectangularPositionSnapGrid.cs  |  5 +++--
 osu.Game/Utils/GeometryUtils.cs                | 18 +++++++++++++++---
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/osu.Game/Screens/Edit/Compose/Components/RectangularPositionSnapGrid.cs b/osu.Game/Screens/Edit/Compose/Components/RectangularPositionSnapGrid.cs
index 160e7e026b..ea9eaf41bb 100644
--- a/osu.Game/Screens/Edit/Compose/Components/RectangularPositionSnapGrid.cs
+++ b/osu.Game/Screens/Edit/Compose/Components/RectangularPositionSnapGrid.cs
@@ -9,6 +9,7 @@ using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
 using osu.Framework.Layout;
 using osu.Framework.Utils;
+using osu.Game.Utils;
 using osuTK;
 
 namespace osu.Game.Screens.Edit.Compose.Components
@@ -215,11 +216,11 @@ namespace osu.Game.Screens.Edit.Compose.Components
 
         public Vector2 GetSnappedPosition(Vector2 original)
         {
-            Vector2 relativeToStart = original - StartPosition;
+            Vector2 relativeToStart = GeometryUtils.RotateVector(original - StartPosition, GridLineRotation);
             Vector2 offset = Vector2.Divide(relativeToStart, Spacing);
             Vector2 roundedOffset = new Vector2(MathF.Round(offset.X), MathF.Round(offset.Y));
 
-            return StartPosition + Vector2.Multiply(roundedOffset, Spacing);
+            return StartPosition + GeometryUtils.RotateVector(Vector2.Multiply(roundedOffset, Spacing), -GridLineRotation);
         }
     }
 }
diff --git a/osu.Game/Utils/GeometryUtils.cs b/osu.Game/Utils/GeometryUtils.cs
index 725e93d098..fcc6b8ae2a 100644
--- a/osu.Game/Utils/GeometryUtils.cs
+++ b/osu.Game/Utils/GeometryUtils.cs
@@ -27,9 +27,8 @@ namespace osu.Game.Utils
             point.X -= origin.X;
             point.Y -= origin.Y;
 
-            Vector2 ret;
-            ret.X = point.X * MathF.Cos(MathUtils.DegreesToRadians(angle)) + point.Y * MathF.Sin(MathUtils.DegreesToRadians(angle));
-            ret.Y = point.X * -MathF.Sin(MathUtils.DegreesToRadians(angle)) + point.Y * MathF.Cos(MathUtils.DegreesToRadians(angle));
+            Vector2 ret = RotateVector(point, angle);
+            Matrix2
 
             ret.X += origin.X;
             ret.Y += origin.Y;
@@ -37,6 +36,19 @@ namespace osu.Game.Utils
             return ret;
         }
 
+        /// <summary>
+        /// Rotate a vector around the origin.
+        /// </summary>
+        /// <param name="vector">The vector.</param>
+        /// <param name="angle">The angle to rotate (in degrees).</param>
+        public static Vector2 RotateVector(Vector2 vector, float angle)
+        {
+            return new Vector2(
+                vector.X * MathF.Cos(MathUtils.DegreesToRadians(angle)) + vector.Y * MathF.Sin(MathUtils.DegreesToRadians(angle)),
+                vector.X * -MathF.Sin(MathUtils.DegreesToRadians(angle)) + vector.Y * MathF.Cos(MathUtils.DegreesToRadians(angle))
+            );
+        }
+
         /// <summary>
         /// Given a flip direction, a surrounding quad for all selected objects, and a position,
         /// will return the flipped position in screen space coordinates.