Add back support for Godot 4.4

Author: dsnopek

gdextension/extension_api-4-4.json

@@ -242,7 +242,11 @@ void ClassDB::_register_class(bool p_virtual, bool p_exposed, bool p_runtime) {
 	class_register_order.push_back(cl.name);
 
 	// Register this class with Godot
+#if GODOT_VERSION_MINOR >= 5
 	GDExtensionClassCreationInfo5 class_info = {
+#else
+	GDExtensionClassCreationInfo4 class_info = {
+#endif
 		p_virtual, // GDExtensionBool is_virtual;
 		is_abstract, // GDExtensionBool is_abstract;
 		p_exposed, // GDExtensionBool is_exposed;
@@ -268,7 +272,11 @@ void ClassDB::_register_class(bool p_virtual, bool p_exposed, bool p_runtime) {
 		(void *)&T::get_class_static(), // void *class_userdata;
 	};
 
+#if GODOT_VERSION_MINOR >= 5
 	::godot::gdextension_interface::classdb_register_extension_class5(::godot::gdextension_interface::library, cl.name._native_ptr(), cl.parent_name._native_ptr(), &class_info);
+#else
+	::godot::gdextension_interface::classdb_register_extension_class4(::godot::gdextension_interface::library, cl.name._native_ptr(), cl.parent_name._native_ptr(), &class_info);
+#endif
 
 	// call bind_methods etc. to register all members of the class
 	T::initialize_class();

include/godot_cpp/core/class_db.hpp

@@ -40,7 +40,11 @@ extern "C" GDExtensionInterfaceGetProcAddress get_proc_address;
 extern "C" GDExtensionClassLibraryPtr library;
 extern "C" void *token;
 
+#if GODOT_VERSION_MINOR >= 5
 extern "C" GDExtensionGodotVersion2 godot_version;
+#else
+extern "C" GDExtensionGodotVersion godot_version;
+#endif
 
 } // namespace gdextension_interface
 
@@ -69,11 +73,13 @@ class GDExtensionBinding {
 		GDExtensionInitializationLevel minimum_initialization_level = GDEXTENSION_INITIALIZATION_CORE;
 		Callback init_callback = nullptr;
 		Callback terminate_callback = nullptr;
+#if GODOT_VERSION_MINOR >= 5
 		GDExtensionMainLoopCallbacks main_loop_callbacks = {};
 
 		inline bool has_main_loop_callbacks() const {
 			return main_loop_callbacks.frame_func || main_loop_callbacks.startup_func || main_loop_callbacks.shutdown_func;
 		}
+#endif
 	};
 
 	class InitDataList {
@@ -108,12 +114,14 @@ class GDExtensionBinding {
 		void register_terminator(Callback p_init) const;
 		void set_minimum_library_initialization_level(ModuleInitializationLevel p_level) const;
 
+#if GODOT_VERSION_MINOR >= 5
 		// Register a callback that is called after all initialization levels when Godot is fully initialized.
 		void register_startup_callback(GDExtensionMainLoopStartupCallback p_callback) const;
 		// Register a callback that is called for every process frame. This will run after all `_process()` methods on Node, and before `ScriptServer::frame()`.
 		void register_frame_callback(GDExtensionMainLoopFrameCallback p_callback) const;
 		// Register a callback that is called before Godot is shutdown when it is still fully initialized.
 		void register_shutdown_callback(GDExtensionMainLoopShutdownCallback p_callback) const;
+#endif
 
 		GDExtensionBool init() const;
 	};

include/godot_cpp/godot.hpp

@@ -50,7 +50,11 @@ GDExtensionInterfaceGetProcAddress get_proc_address = nullptr;
 GDExtensionClassLibraryPtr library = nullptr;
 void *token = nullptr;
 
+#if GODOT_VERSION_MINOR >= 5
 GDExtensionGodotVersion2 godot_version = {};
+#else
+GDExtensionGodotVersion godot_version = {};
+#endif
 
 } // namespace gdextension_interface
 
@@ -142,8 +146,13 @@ GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_ge
 	::godot::gdextension_interface::library = p_library;
 	::godot::gdextension_interface::token = p_library;
 
+#if GODOT_VERSION_MINOR >= 5
 	LOAD_PROC_ADDRESS(get_godot_version2, GDExtensionInterfaceGetGodotVersion2);
 	::godot::gdextension_interface::get_godot_version2(&::godot::gdextension_interface::godot_version);
+#else
+	LOAD_PROC_ADDRESS(get_godot_version, GDExtensionInterfaceGetGodotVersion);
+	::godot::gdextension_interface::get_godot_version(&::godot::gdextension_interface::godot_version);
+#endif
 
 	// Check that godot-cpp was compiled using an extension_api.json older or at the
 	// same version as the Godot that is loading it.
@@ -204,12 +213,16 @@ void GDExtensionBinding::initialize_level(void *p_userdata, GDExtensionInitializ
 	}
 	level_initialized[p_level]++;
 
+#if GODOT_VERSION_MINOR >= 5
 	if ((ModuleInitializationLevel)p_level == MODULE_INITIALIZATION_LEVEL_CORE && init_data && init_data->has_main_loop_callbacks()) {
 		::godot::gdextension_interface::register_main_loop_callbacks(::godot::gdextension_interface::library, &init_data->main_loop_callbacks);
 	}
+#endif
 
 	if ((ModuleInitializationLevel)p_level == MODULE_INITIALIZATION_LEVEL_EDITOR) {
+#if GODOT_VERSION_MINOR >= 5
 		::godot::gdextension_interface::editor_register_get_classes_used_callback(::godot::gdextension_interface::library, &ClassDB::_editor_get_classes_used_callback);
+#endif
 
 		const ::godot::internal::DocData &doc_data = ::godot::internal::get_doc_data();
 		if (doc_data.is_valid()) {
@@ -278,6 +291,7 @@ void GDExtensionBinding::InitObject::set_minimum_library_initialization_level(Mo
 	init_data->minimum_initialization_level = static_cast<GDExtensionInitializationLevel>(p_level);
 }
 
+#if GODOT_VERSION_MINOR >= 5
 void GDExtensionBinding::InitObject::register_startup_callback(GDExtensionMainLoopStartupCallback p_callback) const {
 	init_data->main_loop_callbacks.startup_func = p_callback;
 }
@@ -289,6 +303,7 @@ void GDExtensionBinding::InitObject::register_frame_callback(GDExtensionMainLoop
 void GDExtensionBinding::InitObject::register_shutdown_callback(GDExtensionMainLoopShutdownCallback p_callback) const {
 	init_data->main_loop_callbacks.shutdown_func = p_callback;
 }
+#endif
 
 GDExtensionBool GDExtensionBinding::InitObject::init() const {
 	return GDExtensionBinding::init(get_proc_address, library, init_data, initialization);

src/godot.cpp

@@ -8,6 +8,7 @@ class TestClass:
 
 func _ready():
 	var example: Example = $Example
+	var godot_target_version := example.get_godot_target_version()
 
 	# Timing of set instance binding.
 	assert_equal(example.is_object_binding_set_by_parent_constructor(), true)
@@ -290,12 +291,13 @@ func _ready():
 	assert_equal(library_path, ProjectSettings.globalize_path(library_path))
 	assert_equal(FileAccess.file_exists(library_path), true)
 
-	# Test that internal classes work as expected (at least for Godot 4.5+).
-	assert_equal(ClassDB.can_instantiate("ExampleInternal"), false)
-	assert_equal(ClassDB.instantiate("ExampleInternal"), null)
-	var internal_class = example.test_get_internal_class()
-	assert_equal(internal_class.get_the_answer(), 42)
-	assert_equal(internal_class.get_class(), "ExampleInternal")
+	if godot_target_version[1] >= 5:
+		# Test that internal classes work as expected (at least for Godot 4.5+).
+		assert_equal(ClassDB.can_instantiate("ExampleInternal"), false)
+		assert_equal(ClassDB.instantiate("ExampleInternal"), null)
+		var internal_class = example.test_get_internal_class()
+		assert_equal(internal_class.get_the_answer(), 42)
+		assert_equal(internal_class.get_class(), "ExampleInternal")
 
 	# Test a class with a unicode name.
 	var przykład = ExamplePrzykład.new()

test/project/main.gd

@@ -92,6 +92,15 @@ ExampleRef::ExampleRef() {
 ExampleRef::~ExampleRef() {
 }
 
+Array Example::get_godot_target_version() const {
+	Array ret;
+	ret.resize(3);
+	ret[0] = GODOT_VERSION_MAJOR;
+	ret[1] = GODOT_VERSION_MINOR;
+	ret[2] = GODOT_VERSION_PATCH;
+	return ret;
+}
+
 int Example::test_static(int p_a, int p_b) {
 	return p_a + p_b;
 }
@@ -182,6 +191,7 @@ void Example::_validate_property(PropertyInfo &p_property) const {
 
 void Example::_bind_methods() {
 	// Methods.
+	ClassDB::bind_method(D_METHOD("get_godot_target_version"), &Example::get_godot_target_version);
 	ClassDB::bind_method(D_METHOD("simple_func"), &Example::simple_func);
 	ClassDB::bind_method(D_METHOD("simple_const_func"), &Example::simple_const_func);
 	ClassDB::bind_method(D_METHOD("custom_ref_func", "ref"), &Example::custom_ref_func);

test/src/example.cpp

@@ -108,6 +108,8 @@ class Example : public Control {
 	Example();
 	~Example();
 
+	Array get_godot_target_version() const;
+
 	// Functions.
 	void simple_func();
 	void simple_const_func() const;

test/src/example.h

@@ -176,7 +176,7 @@ def scons_generate_bindings(target, source, env):
     return None
 
 
-api_versions = ["4.5", "4.6"]
+api_versions = ["4.4", "4.5", "4.6"]
 
 platforms = ["linux", "macos", "windows", "android", "ios", "web"]