From 0fec3cb5ed2a009454555440b3853bc4309bc434 Mon Sep 17 00:00:00 2001
From: Ignacio Etcheverry <ignalfonsore@gmail.com>
Date: Wed, 22 Apr 2020 17:19:45 +0200
Subject: [PATCH] Mono/C#: Allow exporting System.Array of type Godot.Object

---
 modules/mono/mono_gd/gd_mono_field.cpp   |  7 ++++++
 modules/mono/mono_gd/gd_mono_marshal.cpp | 31 ++++++++++++++++++++++++
 modules/mono/mono_gd/gd_mono_marshal.h   |  1 +
 3 files changed, 39 insertions(+)

diff --git a/modules/mono/mono_gd/gd_mono_field.cpp b/modules/mono/mono_gd/gd_mono_field.cpp
index 3f4e5fe5ace..e78d88568c3 100644
--- a/modules/mono/mono_gd/gd_mono_field.cpp
+++ b/modules/mono/mono_gd/gd_mono_field.cpp
@@ -322,6 +322,13 @@ void GDMonoField::set_value_from_variant(MonoObject *p_object, const Variant &p_
 				break;
 			}
 
+			GDMonoClass *array_type_class = GDMono::get_singleton()->get_class(array_type->eklass);
+			if (CACHED_CLASS(GodotObject)->is_assignable_from(array_type_class)) {
+				MonoArray *managed = GDMonoMarshal::Array_to_mono_array(p_value.operator ::Array(), array_type_class);
+				mono_field_set_value(p_object, mono_field, managed);
+				break;
+			}
+
 			ERR_FAIL_MSG("Attempted to convert Variant to a managed array of unmarshallable element type.");
 		} break;
 
diff --git a/modules/mono/mono_gd/gd_mono_marshal.cpp b/modules/mono/mono_gd/gd_mono_marshal.cpp
index 1878038f440..c3de059a1d5 100644
--- a/modules/mono/mono_gd/gd_mono_marshal.cpp
+++ b/modules/mono/mono_gd/gd_mono_marshal.cpp
@@ -154,6 +154,10 @@ Variant::Type managed_to_variant_type(const ManagedType &p_type, bool *r_nil_is_
 
 			if (array_type->eklass == CACHED_CLASS_RAW(Color))
 				return Variant::PACKED_COLOR_ARRAY;
+
+			GDMonoClass *array_type_class = GDMono::get_singleton()->get_class(array_type->eklass);
+			if (CACHED_CLASS(GodotObject)->is_assignable_from(array_type_class))
+				return Variant::ARRAY;
 		} break;
 
 		case MONO_TYPE_CLASS: {
@@ -252,6 +256,13 @@ Variant::Type managed_to_variant_type(const ManagedType &p_type, bool *r_nil_is_
 
 bool try_get_array_element_type(const ManagedType &p_array_type, ManagedType &r_elem_type) {
 	switch (p_array_type.type_encoding) {
+		case MONO_TYPE_ARRAY:
+		case MONO_TYPE_SZARRAY: {
+			MonoArrayType *array_type = mono_type_get_array_type(p_array_type.type_class->get_mono_type());
+			GDMonoClass *array_type_class = GDMono::get_singleton()->get_class(array_type->eklass);
+			r_elem_type = ManagedType::from_class(array_type_class);
+			return true;
+		} break;
 		case MONO_TYPE_GENERICINST: {
 			MonoReflectionType *array_reftype = mono_type_get_object(mono_domain_get(), p_array_type.type_class->get_mono_type());
 
@@ -577,6 +588,10 @@ MonoObject *variant_to_mono_object(const Variant *p_var, const ManagedType &p_ty
 			if (array_type->eklass == CACHED_CLASS_RAW(Color))
 				return (MonoObject *)PackedColorArray_to_mono_array(p_var->operator PackedColorArray());
 
+			GDMonoClass *array_type_class = GDMono::get_singleton()->get_class(array_type->eklass);
+			if (CACHED_CLASS(GodotObject)->is_assignable_from(array_type_class))
+				return (MonoObject *)Array_to_mono_array(p_var->operator Array(), array_type_class);
+
 			ERR_FAIL_V_MSG(nullptr, "Attempted to convert Variant to a managed array of unmarshallable element type.");
 		} break;
 
@@ -922,6 +937,10 @@ Variant mono_object_to_variant_impl(MonoObject *p_obj, const ManagedType &p_type
 			if (array_type->eklass == CACHED_CLASS_RAW(Color))
 				return mono_array_to_PackedColorArray((MonoArray *)p_obj);
 
+			GDMonoClass *array_type_class = GDMono::get_singleton()->get_class(array_type->eklass);
+			if (CACHED_CLASS(GodotObject)->is_assignable_from(array_type_class))
+				return mono_array_to_Array((MonoArray *)p_obj);
+
 			if (p_fail_with_err) {
 				ERR_FAIL_V_MSG(Variant(), "Attempted to convert a managed array of unmarshallable element type to Variant.");
 			} else {
@@ -1093,6 +1112,18 @@ MonoArray *Array_to_mono_array(const Array &p_array) {
 	return ret;
 }
 
+MonoArray *Array_to_mono_array(const Array &p_array, GDMonoClass *p_array_type_class) {
+	int length = p_array.size();
+	MonoArray *ret = mono_array_new(mono_domain_get(), p_array_type_class->get_mono_ptr(), length);
+
+	for (int i = 0; i < length; i++) {
+		MonoObject *boxed = variant_to_mono_object(p_array[i]);
+		mono_array_setref(ret, i, boxed);
+	}
+
+	return ret;
+}
+
 Array mono_array_to_Array(MonoArray *p_array) {
 	Array ret;
 	if (!p_array)
diff --git a/modules/mono/mono_gd/gd_mono_marshal.h b/modules/mono/mono_gd/gd_mono_marshal.h
index 8b405291a7e..1837a4a9a11 100644
--- a/modules/mono/mono_gd/gd_mono_marshal.h
+++ b/modules/mono/mono_gd/gd_mono_marshal.h
@@ -126,6 +126,7 @@ String mono_object_to_variant_string(MonoObject *p_obj, MonoException **r_exc);
 // Array
 
 MonoArray *Array_to_mono_array(const Array &p_array);
+MonoArray *Array_to_mono_array(const Array &p_array, GDMonoClass *p_array_type_class);
 Array mono_array_to_Array(MonoArray *p_array);
 
 // PackedInt32Array