Add support for changing LuaScriptLanguage's package_path and package_cpath using project settings

Author: gilzoide

CHANGELOG.md

@@ -8,6 +8,7 @@
 - `LuaState.LoadMode` enum for specifying the Lua load mode: text, binary or any
 - `LuaState.do_buffer` and `LuaState.load_buffer` methods for loading Lua code from possibly binary chunks
 - `LuaState.package_path` and `LuaState.package_cpath` properties for accessing the value of Lua's [`package.path`](https://www.lua.org/manual/5.4/manual.html#pdf-package.path) and [`package.cpath`](https://www.lua.org/manual/5.4/manual.html#pdf-package.cpath)
+- Advanced project settings for setting the `LuaScriptLanguage` state's `package_path` and `package_cpath` properties
 
 ### Changed
 - The GDExtension is now marked as reloadable

src/script-language/LuaScriptLanguage.cpp

@@ -32,6 +32,7 @@
 #include "../utils/function_wrapper.hpp"
 
 #include <godot_cpp/classes/engine.hpp>
+#include <godot_cpp/classes/project_settings.hpp>
 #include <godot_cpp/classes/reg_ex.hpp>
 #include <godot_cpp/classes/reg_ex_match.hpp>
 #include <godot_cpp/classes/resource_loader.hpp>
@@ -40,6 +41,19 @@
 
 namespace luagdextension {
 
+constexpr char LUA_PATH_SETTING[] = "lua_gdextension/lua_script_language/package_path";
+constexpr char LUA_CPATH_SETTING[] = "lua_gdextension/lua_script_language/package_c_path";
+constexpr char LUA_CPATH_WINDOWS_SETTING[] = "lua_gdextension/lua_script_language/package_c_path.windows";
+constexpr char LUA_CPATH_MACOS_SETTING[] = "lua_gdextension/lua_script_language/package_c_path.macos";
+
+static void add_project_setting(ProjectSettings *project_settings, const String& setting_name, const Variant& initial_value, bool is_basic = false) {
+	if (!project_settings->has_setting(setting_name)) {
+		project_settings->set_setting(setting_name, initial_value);
+	}
+	project_settings->set_initial_value(setting_name, initial_value);
+	project_settings->set_as_basic(setting_name, is_basic);
+}
+
 String LuaScriptLanguage::_get_name() const {
 	return "Lua";
 }
@@ -57,6 +71,17 @@ void LuaScriptLanguage::_init() {
 	LuaScriptMethod::register_lua(state);
 	LuaScriptProperty::register_lua(state);
 	LuaScriptSignal::register_lua(state);
+
+	// Register project settings
+	ProjectSettings *project_settings = ProjectSettings::get_singleton();
+	add_project_setting(project_settings, LUA_PATH_SETTING, "res://?.lua;res://?/init.lua");
+	add_project_setting(project_settings, LUA_CPATH_SETTING, "!/?.so;!/loadall.so");
+	add_project_setting(project_settings, LUA_CPATH_WINDOWS_SETTING, "!/?.dll;!/loadall.dll");
+	add_project_setting(project_settings, LUA_CPATH_MACOS_SETTING, "!/?.dylib;!/loadall.dylib");
+
+	// Apply project settings (package.path, package.cpath)
+	lua_state->set_package_path(project_settings->get_setting_with_override(LUA_PATH_SETTING));
+	lua_state->set_package_cpath(project_settings->get_setting_with_override(LUA_CPATH_SETTING));
 }
 
 String LuaScriptLanguage::_get_type() const {