Settings: Add get_flags API for mapgen flags (mg_flags, mgv6_spflags, ...) (#9284)

Unified flags handling in C++ and Lua Settings API
     -> Reading only, for now. Writing can be implemented later, if needed.
API function to read the currently active flags
     -> was impossible from Lua

Co-authored-by: Wuzzy <wuzzy2@mail.ru>

2 files changed, 28 insertions, 0 deletions

diff --git a/src/script/lua_api/l_settings.cpp b/src/script/lua_api/l_settings.cpp
index cc2c73789..33eb02392 100644
--- a/src/script/lua_api/l_settings.cpp
+++ b/src/script/lua_api/l_settings.cpp
@@ -20,6 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "lua_api/l_settings.h"
 #include "lua_api/l_internal.h"
 #include "cpp_api/s_security.h"
+#include "util/string.h" // FlagDesc
 #include "settings.h"
 #include "noise.h"
 #include "log.h"
@@ -128,6 +129,29 @@ int LuaSettings::l_get_np_group(lua_State *L)
 	return 1;
 }
 
+int LuaSettings::l_get_flags(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+	LuaSettings *o = checkobject(L, 1);
+	std::string key = std::string(luaL_checkstring(L, 2));
+
+	u32 flags = 0;
+	auto flagdesc = o->m_settings->getFlagDescFallback(key);
+	if (o->m_settings->getFlagStrNoEx(key, flags, flagdesc)) {
+		lua_newtable(L);
+		int table = lua_gettop(L);
+		for (size_t i = 0; flagdesc[i].name; ++i) {
+			lua_pushboolean(L, flags & flagdesc[i].flag);
+			lua_setfield(L, table, flagdesc[i].name);
+		}
+		lua_pushvalue(L, table);
+	} else {
+		lua_pushnil(L);
+	}
+
+	return 1;
+}
+
 // set(self, key, value)
 int LuaSettings::l_set(lua_State* L)
 {
@@ -305,6 +329,7 @@ const luaL_Reg LuaSettings::methods[] = {
 	luamethod(LuaSettings, get),
 	luamethod(LuaSettings, get_bool),
 	luamethod(LuaSettings, get_np_group),
+	luamethod(LuaSettings, get_flags),
 	luamethod(LuaSettings, set),
 	luamethod(LuaSettings, set_bool),
 	luamethod(LuaSettings, set_np_group),
diff --git a/src/script/lua_api/l_settings.h b/src/script/lua_api/l_settings.h
index dcf39a89e..67d7b342b 100644
--- a/src/script/lua_api/l_settings.h
+++ b/src/script/lua_api/l_settings.h
@@ -42,6 +42,9 @@ private:
 	// get_np_group(self, key) -> noiseparam
 	static int l_get_np_group(lua_State *L);
 
+	// get_flags(self, key) -> key/value table
+	static int l_get_flags(lua_State *L);
+
 	// set(self, key, value)
 	static int l_set(lua_State *L);