Add core.get_mapgen_names() to Main Menu API (and use it)

Also rewrite mapgen registration for static initialization

builtin/mainmenu/dlg_create_world.lua

@@ -16,7 +16,7 @@
 --51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 local function create_world_formspec(dialogdata)
-	local mapgens = {"v5", "v6", "v7", "singlenode"}
+	local mapgens = core.get_mapgen_names()
 
 	local current_seed = core.setting_get("fixed_map_seed") or ""
 	local current_mg   = core.setting_get("mg_name")

doc/menu_lua_api.txt

@@ -143,6 +143,8 @@ core.get_game(index)
 	addon_mods_paths = {[1] = <path>,},
 }
 core.get_games() -> table of all games in upper format (possible in async calls)
+core.get_mapgen_names() -> table of all map generator algorithms registered in
+                           the core (possible in async calls)
 
 Favorites:
 core.get_favorites(location) -> list of favorites (possible in async calls)

src/emerge.cpp

@@ -48,6 +48,17 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapgen_v7.h"
 #include "mapgen_singlenode.h"
 
+struct MapgenDesc {
+	const char *name;
+	MapgenFactory *factory;
+};
+
+MapgenDesc reg_mapgens[] = {
+	{"v5",         new MapgenFactoryV5},
+	{"v6",         new MapgenFactoryV6},
+	{"v7",         new MapgenFactoryV7},
+	{"singlenode", new MapgenFactorySinglenode},
+};
 
 class EmergeThread : public JThread
 {
@@ -84,12 +95,6 @@ public:
 
 EmergeManager::EmergeManager(IGameDef *gamedef)
 {
-	//register built-in mapgens
-	registerMapgen("v5",         new MapgenFactoryV5());
-	registerMapgen("v6",         new MapgenFactoryV6());
-	registerMapgen("v7",         new MapgenFactoryV7());
-	registerMapgen("singlenode", new MapgenFactorySinglenode());
-
 	this->ndef      = gamedef->getNodeDefManager();
 	this->biomemgr  = new BiomeManager(gamedef);
 	this->oremgr    = new OreManager(gamedef);
@@ -147,11 +152,6 @@ EmergeManager::~EmergeManager()
 	emergethread.clear();
 	mapgen.clear();
 
-	std::map<std::string, MapgenFactory *>::iterator it;
-	for (it = mglist.begin(); it != mglist.end(); ++it)
-		delete it->second;
-	mglist.clear();
-
 	delete biomemgr;
 	delete oremgr;
 	delete decomgr;
@@ -334,33 +334,40 @@ u32 EmergeManager::getBlockSeed(v3s16 p)
 }
 
 
-Mapgen *EmergeManager::createMapgen(std::string mgname, int mgid,
+void EmergeManager::getMapgenNames(std::list<const char *> &mgnames)
+{
+	for (u32 i = 0; i != ARRLEN(reg_mapgens); i++)
+		mgnames.push_back(reg_mapgens[i].name);
+}
+
+
+Mapgen *EmergeManager::createMapgen(const std::string &mgname, int mgid,
 	MapgenParams *mgparams)
 {
-	std::map<std::string, MapgenFactory *>::const_iterator iter;
-	iter = mglist.find(mgname);
-	if (iter == mglist.end()) {
+	u32 i;
+	for (i = 0; i != ARRLEN(reg_mapgens) && mgname != reg_mapgens[i].name; i++);
+	if (i == ARRLEN(reg_mapgens)) {
 		errorstream << "EmergeManager; mapgen " << mgname <<
 			" not registered" << std::endl;
 		return NULL;
 	}
 
-	MapgenFactory *mgfactory = iter->second;
+	MapgenFactory *mgfactory = reg_mapgens[i].factory;
 	return mgfactory->createMapgen(mgid, mgparams, this);
 }
 
 
-MapgenSpecificParams *EmergeManager::createMapgenParams(std::string mgname)
+MapgenSpecificParams *EmergeManager::createMapgenParams(const std::string &mgname)
 {
-	std::map<std::string, MapgenFactory *>::const_iterator iter;
-	iter = mglist.find(mgname);
-	if (iter == mglist.end()) {
-		errorstream << "EmergeManager: mapgen " << mgname <<
+	u32 i;
+	for (i = 0; i != ARRLEN(reg_mapgens) && mgname != reg_mapgens[i].name; i++);
+	if (i == ARRLEN(reg_mapgens)) {
+		errorstream << "EmergeManager; mapgen " << mgname <<
 			" not registered" << std::endl;
 		return NULL;
 	}
 
-	MapgenFactory *mgfactory = iter->second;
+	MapgenFactory *mgfactory = reg_mapgens[i].factory;
 	return mgfactory->createMapgenParams();
 }
 
@@ -402,13 +409,6 @@ void EmergeManager::saveParamsToSettings(Settings *settings)
 }
 
 
-void EmergeManager::registerMapgen(std::string mgname, MapgenFactory *mgfactory)
-{
-	mglist.insert(std::make_pair(mgname, mgfactory));
-	infostream << "EmergeManager: registered mapgen " << mgname << std::endl;
-}
-
-
 ////////////////////////////// Emerge Thread //////////////////////////////////
 
 bool EmergeThread::popBlockEmerge(v3s16 *pos, u8 *flags)

src/emerge.h

@@ -70,8 +70,6 @@ class EmergeManager {
 public:
 	INodeDefManager *ndef;
 
-	std::map<std::string, MapgenFactory *> mglist;
-
 	std::vector<Mapgen *> mapgen;
 	std::vector<EmergeThread *> emergethread;
 
@@ -105,14 +103,14 @@ public:
 	void loadMapgenParams();
 	void initMapgens();
 	Mapgen *getCurrentMapgen();
-	Mapgen *createMapgen(std::string mgname, int mgid,
+	Mapgen *createMapgen(const std::string &mgname, int mgid,
 		MapgenParams *mgparams);
-	MapgenSpecificParams *createMapgenParams(std::string mgname);
+	MapgenSpecificParams *createMapgenParams(const std::string &mgname);
+	static void getMapgenNames(std::list<const char *> &mgnames);
 	void startThreads();
 	void stopThreads();
 	bool enqueueBlockEmerge(u16 peer_id, v3s16 p, bool allow_generate);
 
-	void registerMapgen(std::string name, MapgenFactory *mgfactory);
 	void loadParamsFromSettings(Settings *settings);
 	void saveParamsToSettings(Settings *settings);
 

src/script/lua_api/l_mainmenu.cpp

@@ -31,6 +31,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "filesys.h"
 #include "convert_json.h"
 #include "serverlist.h"
+#include "emerge.h"
 #include "sound.h"
 #include "settings.h"
 #include "main.h" // for g_settings
@@ -688,6 +689,25 @@ int ModApiMainMenu::l_set_topleft_text(lua_State *L)
 	return 0;
 }
 
+/******************************************************************************/
+int ModApiMainMenu::l_get_mapgen_names(lua_State *L)
+{
+	lua_newtable(L);
+
+	std::list<const char *> names;
+	EmergeManager::getMapgenNames(names);
+
+	int i = 1;
+	for (std::list<const char *>::const_iterator
+			it = names.begin(); it != names.end(); ++it) {
+		lua_pushstring(L, *it);
+		lua_rawseti(L, -2, i++);
+	}
+
+	return 1;
+}
+
+
 /******************************************************************************/
 int ModApiMainMenu::l_get_modpath(lua_State *L)
 {
@@ -1107,6 +1127,7 @@ void ModApiMainMenu::Initialize(lua_State *L, int top)
 	API_FCT(delete_favorite);
 	API_FCT(set_background);
 	API_FCT(set_topleft_text);
+	API_FCT(get_mapgen_names);
 	API_FCT(get_modpath);
 	API_FCT(get_gamepath);
 	API_FCT(get_texturepath);
@@ -1137,6 +1158,7 @@ void ModApiMainMenu::InitializeAsync(AsyncEngine& engine)
 	ASYNC_API_FCT(get_worlds);
 	ASYNC_API_FCT(get_games);
 	ASYNC_API_FCT(get_favorites);
+	ASYNC_API_FCT(get_mapgen_names);
 	ASYNC_API_FCT(get_modpath);
 	ASYNC_API_FCT(get_gamepath);
 	ASYNC_API_FCT(get_texturepath);

src/script/lua_api/l_mainmenu.h

@@ -73,6 +73,8 @@ private:
 
 	static int l_get_games(lua_State *L);
 
+	static int l_get_mapgen_names(lua_State *L);
+
 	static int l_get_favorites(lua_State *L);
 
 	static int l_delete_favorite(lua_State *L);