Add WorldElementExtensions with extensions to get the allocating user

Author: Banane9

MonkeyLoader.Resonite.Core/WorldElementExtensions.cs

@@ -0,0 +1,48 @@
+using FrooxEngine;
+using System.Diagnostics.CodeAnalysis;
+
+namespace MonkeyLoader.Resonite
+{
+    /// <summary>
+    /// Contains extensions for <see cref="IWorldElement">world elements</see>.
+    /// </summary>
+    public static class WorldElementExtensions
+    {
+        /// <summary>
+        /// Gets the allocating <see cref="User"/> of this <see cref="IWorldElement">world element</see>.
+        /// </summary>
+        /// <remarks>
+        /// Implementation is the same as the Allocating User ProtoFlux node.
+        /// </remarks>
+        /// <param name="element">The world element to get the allocating <see cref="User"/> of.</param>
+        /// <returns>This <see cref="IWorldElement">world element</see>'s allocating <see cref="User"/> if valid; otherwise, <see langword="null"/>.</returns>
+        public static User? GetAllocatingUser(this IWorldElement? element)
+        {
+            if (element!.FilterWorldElement() is null)
+                return null;
+
+            element!.ReferenceID.ExtractIDs(out var position, out var allocationId);
+            var user = element.World.GetUserByAllocationID(allocationId);
+
+            if (user is null || position < user.AllocationIDStart)
+                return null;
+
+            return user;
+        }
+
+        /// <summary>
+        /// Tries to get the allocating <see cref="User"/> of this <see cref="IWorldElement">world element</see>.
+        /// </summary>
+        /// <remarks>
+        /// Implementation is the same as the Allocating User ProtoFlux node.
+        /// </remarks>
+        /// <param name="element">The world element to get the allocating <see cref="User"/> of.</param>
+        /// <param name="user">This <see cref="IWorldElement">world element</see>'s allocating <see cref="User"/> if valid; otherwise, <see langword="null"/>.</param>
+        /// <returns><see langword="true"/> if this <see cref="IWorldElement">world element</see> has a valid allocating <see cref="User"/>; otherwise, <see langword="false"/>.</returns>
+        public static bool TryGetAllocatingUser(this IWorldElement? element, [NotNullWhen(true)] out User? user)
+        {
+            user = element.GetAllocatingUser();
+            return user is not null;
+        }
+    }
+}