Fix marshalling Array<Variant> as object[] (C# codegen error)

Source/Engine/Engine/NativeInterop.Managed.cs

@@ -371,7 +371,6 @@ namespace FlaxEngine.Interop
         {
             if (handle == IntPtr.Zero)
                 return;
-
             ManagedHandlePool.FreeHandle(handle);
             handle = IntPtr.Zero;
         }

Source/Engine/Engine/NativeInterop.Marshallers.cs

@@ -183,6 +183,9 @@ namespace FlaxEngine.Interop
         public static void Free(IntPtr unmanaged) => ManagedHandleMarshaller.Free(unmanaged);
     }
 
+#if FLAX_EDITOR
+    [HideInEditor]
+#endif
     [CustomMarshaller(typeof(Array), MarshalMode.ManagedToUnmanagedIn, typeof(SystemArrayMarshaller.ManagedToNative))]
     [CustomMarshaller(typeof(Array), MarshalMode.UnmanagedToManagedOut, typeof(SystemArrayMarshaller.ManagedToNative))]
     [CustomMarshaller(typeof(Array), MarshalMode.ManagedToUnmanagedOut, typeof(SystemArrayMarshaller.NativeToManaged))]
@@ -251,6 +254,74 @@ namespace FlaxEngine.Interop
         }
     }
 
+#if FLAX_EDITOR
+    [HideInEditor]
+#endif
+    [CustomMarshaller(typeof(object[]), MarshalMode.ManagedToUnmanagedIn, typeof(SystemObjectArrayMarshaller.ManagedToNative))]
+    [CustomMarshaller(typeof(object[]), MarshalMode.UnmanagedToManagedOut, typeof(SystemObjectArrayMarshaller.ManagedToNative))]
+    [CustomMarshaller(typeof(object[]), MarshalMode.ManagedToUnmanagedOut, typeof(SystemObjectArrayMarshaller.NativeToManaged))]
+    [CustomMarshaller(typeof(object[]), MarshalMode.UnmanagedToManagedIn, typeof(SystemObjectArrayMarshaller.NativeToManaged))]
+    public static unsafe class SystemObjectArrayMarshaller
+    {
+#if FLAX_EDITOR
+        [HideInEditor]
+#endif
+        public struct ManagedToNative
+        {
+            ManagedHandle handle;
+
+            public void FromManaged(object[] managed)
+            {
+                if (managed != null)
+                {
+                    var managedArray = NativeInterop.ManagedArrayToGCHandleWrappedArray(managed);
+                    handle = ManagedHandle.Alloc(managedArray, GCHandleType.Weak);
+                }
+            }
+
+            public IntPtr ToUnmanaged()
+            {
+                return ManagedHandle.ToIntPtr(handle);
+            }
+
+            public void Free()
+            {
+                handle.Free();
+            }
+        }
+
+#if FLAX_EDITOR
+        [HideInEditor]
+#endif
+        public struct NativeToManaged
+        {
+            ManagedHandle handle;
+
+            public void FromUnmanaged(IntPtr unmanaged)
+            {
+                if (unmanaged == IntPtr.Zero)
+                    return;
+                handle = ManagedHandle.FromIntPtr(unmanaged);
+            }
+
+            public object[] ToManaged()
+            {
+                object[] result = null;
+                if (handle.IsAllocated)
+                {
+                    var managedArray = Unsafe.As<ManagedArray>(handle.Target);
+                    result = NativeInterop.GCHandleArrayToManagedArray<object>(managedArray);
+                }
+                return result;
+            }
+
+            public void Free()
+            {
+                handle.Free();
+            }
+        }
+    }
+
 #if FLAX_EDITOR
     [HideInEditor]
 #endif

Source/Tools/Flax.Build/Bindings/BindingsGenerator.CSharp.cs

@@ -521,7 +521,7 @@ namespace Flax.Build.Bindings
                 returnMarshalType = "MarshalUsing(typeof(FlaxEngine.Interop.SystemTypeMarshaller))";
             else if (returnValueType == "CultureInfo")
                 returnMarshalType = "MarshalUsing(typeof(FlaxEngine.Interop.CultureInfoMarshaller))";
-            else if (functionInfo.ReturnType.Type == "Variant")
+            else if (functionInfo.ReturnType.Type == "Variant") // object
                 returnMarshalType = "MarshalUsing(typeof(FlaxEngine.Interop.ManagedHandleMarshaller))";
             else if (FindApiTypeInfo(buildData, functionInfo.ReturnType, caller)?.IsInterface ?? false)
             {
@@ -530,6 +530,8 @@ namespace Flax.Build.Bindings
             }
             else if (functionInfo.ReturnType.Type == "MonoArray" || functionInfo.ReturnType.Type == "MArray")
                 returnMarshalType = "MarshalUsing(typeof(FlaxEngine.Interop.SystemArrayMarshaller))";
+            else if (returnValueType == "object[]")
+                returnMarshalType = "MarshalUsing(typeof(FlaxEngine.Interop.SystemObjectArrayMarshaller))";
             else if (functionInfo.ReturnType.Type == "Array" || functionInfo.ReturnType.Type == "Span" || functionInfo.ReturnType.Type == "DataContainer" || functionInfo.ReturnType.Type == "BytesContainer" || returnNativeType == "Array")
                 returnMarshalType = $"MarshalUsing(typeof(FlaxEngine.Interop.ArrayMarshaller<,>), CountElementName = nameof(__returnCount))";
             else if (functionInfo.ReturnType.Type == "Dictionary")
@@ -579,6 +581,8 @@ namespace Flax.Build.Bindings
                     parameterMarshalType = "MarshalUsing(typeof(FlaxEngine.Interop.ManagedHandleMarshaller))";
                 else if (parameterInfo.Type.Type == "MonoArray" || parameterInfo.Type.Type == "MArray")
                     parameterMarshalType = "MarshalUsing(typeof(FlaxEngine.Interop.SystemArrayMarshaller))";
+                else if (nativeType == "object[]")
+                    parameterMarshalType = "MarshalUsing(typeof(FlaxEngine.Interop.SystemObjectArrayMarshaller))";
                 else if (parameterInfo.Type.Type == "Array" && parameterInfo.Type.GenericArgs.Count > 0 && parameterInfo.Type.GenericArgs[0].Type == "bool")
                     parameterMarshalType = $"MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.U1, SizeParamIndex = {(!functionInfo.IsStatic ? 1 : 0) + functionInfo.Parameters.Count + (functionInfo.Glue.CustomParameters.FindIndex(x => x.Name == $"__{parameterInfo.Name}Count"))})";
                 else if (parameterInfo.Type.Type == "Array" || parameterInfo.Type.Type == "Span" || parameterInfo.Type.Type == "DataContainer" || parameterInfo.Type.Type == "BytesContainer" || nativeType == "Array")