update LuaUnit

engine/lua/LuaUnit.cpp

@@ -262,6 +262,18 @@ CE_EXPORT int unit_controller(lua_State* L)
 	return 1;
 }
 
+//-----------------------------------------------------------------------------
+CE_EXPORT int unit_is_a(lua_State* L)
+{
+	LuaStack stack(L);
+
+	Unit* unit = stack.get_unit(1);
+	const char* name = stack.get_string(2);
+
+	stack.push_bool(unit->is_a(name));
+	return 1;
+}
+
 //-----------------------------------------------------------------------------
 void load_unit(LuaEnvironment& env)
 {
@@ -286,6 +298,8 @@ void load_unit(LuaEnvironment& env)
 	env.load_module_function("Unit", "sprite",					unit_sprite);
 	env.load_module_function("Unit", "actor",					unit_actor);
 	env.load_module_function("Unit", "controller",				unit_controller);
+
+	env.load_module_function("Unit", "is_a",					unit_is_a);
 }
 
 } // namespace crown