Add automatic replication for C# types with fields marked with NetworkReplicated attribute

Source/Engine/Networking/NetworkReplicator.cs

@@ -0,0 +1,97 @@
+// Copyright (c) 2012-2022 Wojciech Figat. All rights reserved.
+
+using System;
+using System.Runtime.InteropServices;
+using System.Collections.Generic;
+
+namespace FlaxEngine.Networking
+{
+    partial class NetworkReplicator
+    {
+        private static Dictionary<Type, KeyValuePair<SerializeFunc, SerializeFunc>> _managedSerializers;
+
+#if FLAX_EDITOR
+        private static void OnScriptsReloadBegin()
+        {
+            // Clear refs to managed types that will be hot-reloaded
+            _managedSerializers.Clear();
+            _managedSerializers = null;
+            FlaxEditor.ScriptsBuilder.ScriptsReloadBegin -= OnScriptsReloadBegin;
+        }
+#endif
+
+        /// <summary>
+        /// Network object replication serialization/deserialization delegate.
+        /// </summary>
+        /// <remarks>
+        /// Use Object.FromUnmanagedPtr(instancePtr/streamPtr) to get object or NetworkStream from raw native pointers.
+        /// </remarks>
+        /// <param name="instancePtr">var instance = Object.FromUnmanagedPtr(instancePtr)</param>
+        /// <param name="streamPtr">var stream = (NetworkStream)Object.FromUnmanagedPtr(streamPtr)</param>
+        public delegate void SerializeFunc(IntPtr instancePtr, IntPtr streamPtr);
+
+        /// <summary>
+        /// Registers a new serialization methods for a given C# type.
+        /// </summary>
+        /// <remarks>
+        /// Use Object.FromUnmanagedPtr(instancePtr/streamPtr) to get object or NetworkStream from raw native pointers.
+        /// </remarks>
+        /// <param name="type">The C# type (class or structure).</param>
+        /// <param name="serialize">Function to call for value serialization.</param>
+        /// <param name="deserialize">Function to call for value deserialization.</param>
+        [Unmanaged]
+        public static void AddSerializer(Type type, SerializeFunc serialize, SerializeFunc deserialize)
+        {
+            // C#-only types (eg. custom C# structures) cannot use native serializers due to missing ScriptingType
+            if (typeof(FlaxEngine.Object).IsAssignableFrom(type))
+            {
+                Internal_AddSerializer(type, Marshal.GetFunctionPointerForDelegate(serialize), Marshal.GetFunctionPointerForDelegate(deserialize));
+            }
+            else
+            {
+                if (_managedSerializers == null)
+                {
+                    _managedSerializers = new Dictionary<Type, KeyValuePair<SerializeFunc, SerializeFunc>>();
+#if FLAX_EDITOR
+                    FlaxEditor.ScriptsBuilder.ScriptsReloadBegin += OnScriptsReloadBegin;
+#endif
+                }
+                _managedSerializers[type] = new KeyValuePair<SerializeFunc, SerializeFunc>(serialize, deserialize);
+            }
+        }
+
+        /// <summary>
+        /// Invokes the network replication serializer for a given type.
+        /// </summary>
+        /// <param name="type">The scripting type to serialize.</param>
+        /// <param name="instance">The value instance to serialize.</param>
+        /// <param name="stream">The input/output stream to use for serialization.</param>
+        /// <param name="serialize">True if serialize, otherwise deserialize mode.</param>
+        /// <returns>True if failed, otherwise false.</returns>
+        [Unmanaged]
+        public static bool InvokeSerializer(Type type, FlaxEngine.Object instance, NetworkStream stream, bool serialize)
+        {
+            return Internal_InvokeSerializer(type, FlaxEngine.Object.GetUnmanagedPtr(instance), FlaxEngine.Object.GetUnmanagedPtr(stream), serialize);
+        }
+
+        /// <summary>
+        /// Invokes the network replication serializer for a given type.
+        /// </summary>
+        /// <param name="type">The scripting type to serialize.</param>
+        /// <param name="instance">The value instance to serialize.</param>
+        /// <param name="stream">The input/output stream to use for serialization.</param>
+        /// <param name="serialize">True if serialize, otherwise deserialize mode.</param>
+        /// <returns>True if failed, otherwise false.</returns>
+        [Unmanaged]
+        public static bool InvokeSerializer(System.Type type, IntPtr instance, NetworkStream stream, bool serialize)
+        {
+            if (_managedSerializers != null && _managedSerializers.TryGetValue(type, out var e))
+            {
+                var serializer = serialize ? e.Key : e.Value;
+                serializer(instance, FlaxEngine.Object.GetUnmanagedPtr(stream));
+                return false;
+            }
+            return Internal_InvokeSerializer(type, instance, FlaxEngine.Object.GetUnmanagedPtr(stream), serialize);
+        }
+    }
+}