From d1d83d7e7f5e2e7cbef5272eda9c580129e301a3 Mon Sep 17 00:00:00 2001
From: Perttu Ahola <celeron55@gmail.com>
Date: Sun, 11 Mar 2012 20:45:14 +0200
Subject: [PATCH] World selection box in main menu (and random fixing)

---
 minetest.conf.example   |   2 +
 src/defaultsettings.cpp |   2 +
 src/guiMainMenu.cpp     |  85 ++++++++++-------
 src/guiMainMenu.h       |  12 ++-
 src/main.cpp            | 207 ++++++++++++++++++++++++++++------------
 src/subgame.cpp         |  57 ++++++++++-
 src/subgame.h           |  28 +++++-
 7 files changed, 291 insertions(+), 102 deletions(-)

diff --git a/minetest.conf.example b/minetest.conf.example
index a82ead6e..4e55a34f 100644
--- a/minetest.conf.example
+++ b/minetest.conf.example
@@ -115,6 +115,8 @@
 # Server stuff
 #
 
+# Default game (default when creating a new world)
+#default_game = mesetint
 # Map directory (everything in the world is stored here)
 #map-dir = /custom/map
 # Message of the Day
diff --git a/src/defaultsettings.cpp b/src/defaultsettings.cpp
index 23199eef..67626d34 100644
--- a/src/defaultsettings.cpp
+++ b/src/defaultsettings.cpp
@@ -94,8 +94,10 @@ void set_default_settings(Settings *settings)
 	settings->setDefault("opaque_water", "false");
 	settings->setDefault("console_color", "(0,0,0)");
 	settings->setDefault("console_alpha", "200");
+
 	// Server stuff
 	// "map-dir" doesn't exist by default.
+	settings->setDefault("default_game", "mesetint");
 	settings->setDefault("motd", "");
 	settings->setDefault("max_users", "100");
 	settings->setDefault("strict_protocol_version_checking", "true");
diff --git a/src/guiMainMenu.cpp b/src/guiMainMenu.cpp
index 5c6104ca..68348cbb 100644
--- a/src/guiMainMenu.cpp
+++ b/src/guiMainMenu.cpp
@@ -27,6 +27,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <IGUIButton.h>
 #include <IGUIStaticText.h>
 #include <IGUIFont.h>
+#include <IGUIListBox.h>
 
 
 #include "gettext.h"
@@ -73,65 +74,52 @@ void GUIMainMenu::removeChildren()
 
 void GUIMainMenu::regenerateGui(v2u32 screensize)
 {
-	std::wstring text_name;
-	std::wstring text_address;
-	std::wstring text_port;
-	bool creative_mode;
-	bool enable_damage;
-	bool fancy_trees;
-	bool smooth_lighting;
-	bool clouds_3d;
-	bool opaque_water;
+	std::wstring text_name = m_data->name;
+	std::wstring text_address = m_data->address;
+	std::wstring text_port = m_data->port;
+	bool creative_mode = m_data->creative_mode;
+	bool enable_damage = m_data->enable_damage;
+	bool fancy_trees = m_data->fancy_trees;
+	bool smooth_lighting = m_data->smooth_lighting;
+	bool clouds_3d = m_data->clouds_3d;
+	bool opaque_water = m_data->opaque_water;
+	int selected_world = m_data->selected_world;
 	
 	// Client options
 	{
 		gui::IGUIElement *e = getElementFromId(GUI_ID_NAME_INPUT);
 		if(e != NULL)
 			text_name = e->getText();
-		else
-			text_name = m_data->name;
 	}
 	{
 		gui::IGUIElement *e = getElementFromId(GUI_ID_ADDRESS_INPUT);
 		if(e != NULL)
 			text_address = e->getText();
-		else
-			text_address = m_data->address;
 	}
 	{
 		gui::IGUIElement *e = getElementFromId(GUI_ID_PORT_INPUT);
 		if(e != NULL)
 			text_port = e->getText();
-		else
-			text_port = m_data->port;
 	}
 	{
 		gui::IGUIElement *e = getElementFromId(GUI_ID_FANCYTREE_CB);
 		if(e != NULL && e->getType() == gui::EGUIET_CHECK_BOX)
 			fancy_trees = ((gui::IGUICheckBox*)e)->isChecked();
-		else
-			fancy_trees = m_data->fancy_trees;
 	}
 	{
 		gui::IGUIElement *e = getElementFromId(GUI_ID_SMOOTH_LIGHTING_CB);
 		if(e != NULL && e->getType() == gui::EGUIET_CHECK_BOX)
 			smooth_lighting = ((gui::IGUICheckBox*)e)->isChecked();
-		else
-			smooth_lighting = m_data->smooth_lighting;
 	}
 	{
 		gui::IGUIElement *e = getElementFromId(GUI_ID_3D_CLOUDS_CB);
 		if(e != NULL && e->getType() == gui::EGUIET_CHECK_BOX)
 			clouds_3d = ((gui::IGUICheckBox*)e)->isChecked();
-		else
-			clouds_3d = m_data->clouds_3d;
 	}
 	{
 		gui::IGUIElement *e = getElementFromId(GUI_ID_OPAQUE_WATER_CB);
 		if(e != NULL && e->getType() == gui::EGUIET_CHECK_BOX)
 			opaque_water = ((gui::IGUICheckBox*)e)->isChecked();
-		else
-			opaque_water = m_data->opaque_water;
 	}
 	
 	// Server options
@@ -139,15 +127,16 @@ void GUIMainMenu::regenerateGui(v2u32 screensize)
 		gui::IGUIElement *e = getElementFromId(GUI_ID_CREATIVE_CB);
 		if(e != NULL && e->getType() == gui::EGUIET_CHECK_BOX)
 			creative_mode = ((gui::IGUICheckBox*)e)->isChecked();
-		else
-			creative_mode = m_data->creative_mode;
 	}
 	{
 		gui::IGUIElement *e = getElementFromId(GUI_ID_DAMAGE_CB);
 		if(e != NULL && e->getType() == gui::EGUIET_CHECK_BOX)
 			enable_damage = ((gui::IGUICheckBox*)e)->isChecked();
-		else
-			enable_damage = m_data->enable_damage;
+	}
+	{
+		gui::IGUIElement *e = getElementFromId(GUI_ID_WORLD_LISTBOX);
+		if(e != NULL && e->getType() == gui::EGUIET_LIST_BOX)
+			selected_world = ((gui::IGUIListBox*)e)->getSelected();
 	}
 
 	/*
@@ -318,24 +307,36 @@ void GUIMainMenu::regenerateGui(v2u32 screensize)
 	// Server parameters
 	{
 		core::rect<s32> rect(0, 0, 250, 30);
-		rect += topleft_server + v2s32(35, 20);
+		rect += topleft_server + v2s32(20+250+20, 20);
 		Environment->addCheckBox(creative_mode, rect, this, GUI_ID_CREATIVE_CB,
 			wgettext("Creative Mode"));
 	}
 	{
 		core::rect<s32> rect(0, 0, 250, 30);
-		rect += topleft_server + v2s32(35, 40);
+		rect += topleft_server + v2s32(20+250+20, 40);
 		Environment->addCheckBox(enable_damage, rect, this, GUI_ID_DAMAGE_CB,
 			wgettext("Enable Damage"));
 	}
 	// Map delete button
 	{
 		core::rect<s32> rect(0, 0, 130, 30);
-		//rect += topleft_server + v2s32(size_server.X-40-130, 100+25);
-		rect += topleft_server + v2s32(40, 90);
+		rect += topleft_server + v2s32(20+250+20, 90);
 		Environment->addButton(rect, this, GUI_ID_DELETE_MAP_BUTTON,
 			  wgettext("Delete map"));
 	}
+	// World selection listbox
+	{
+		core::rect<s32> rect(0, 0, 250, 120);
+		rect += topleft_server + v2s32(20, 10);
+		gui::IGUIListBox *e = Environment->addListBox(rect, this,
+				GUI_ID_WORLD_LISTBOX);
+		e->setDrawBackground(true);
+		for(std::list<std::wstring>::const_iterator i = m_data->worlds.begin();
+				i != m_data->worlds.end(); i++){
+			e->addItem(i->c_str());
+		}
+		e->setSelected(selected_world);
+	}
 	changeCtype("C");
 }
 
@@ -418,6 +419,12 @@ void GUIMainMenu::acceptInput()
 		if(e != NULL && e->getType() == gui::EGUIET_CHECK_BOX)
 			m_data->opaque_water = ((gui::IGUICheckBox*)e)->isChecked();
 	}
+
+	{
+		gui::IGUIElement *e = getElementFromId(GUI_ID_WORLD_LISTBOX);
+		if(e != NULL && e->getType() == gui::EGUIET_LIST_BOX)
+			m_data->selected_world = ((gui::IGUIListBox*)e)->getSelected();
+	}
 	
 	m_accepted = true;
 }
@@ -466,9 +473,8 @@ bool GUIMainMenu::OnEvent(const SEvent& event)
 				return true;
 			}
 			case GUI_ID_DELETE_MAP_BUTTON: // Delete map
-				// Don't accept input data, just set deletion request
-				m_data->delete_map = true;
-				m_accepted = true;
+				acceptInput();
+				m_data->delete_world = true;
 				quitMenu();
 				return true;
 			}
@@ -483,6 +489,17 @@ bool GUIMainMenu::OnEvent(const SEvent& event)
 				return true;
 			}
 		}
+		if(event.GUIEvent.EventType==gui::EGET_LISTBOX_SELECTED_AGAIN)
+		{
+			switch(event.GUIEvent.Caller->getID())
+			{
+				case GUI_ID_WORLD_LISTBOX:
+				acceptInput();
+				m_data->address = L""; // Force local game
+				quitMenu();
+				return true;
+			}
+		}
 	}
 
 	return Parent ? Parent->OnEvent(event) : false;
diff --git a/src/guiMainMenu.h b/src/guiMainMenu.h
index ba2fc6be..8ef28624 100644
--- a/src/guiMainMenu.h
+++ b/src/guiMainMenu.h
@@ -26,6 +26,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <string>
 // For IGameCallback
 #include "guiPauseMenu.h"
+#include <list>
 
 enum
 {
@@ -41,7 +42,8 @@ enum
 	GUI_ID_CREATIVE_CB,
 	GUI_ID_JOIN_GAME_BUTTON,
 	GUI_ID_CHANGE_KEYS_BUTTON,
-	GUI_ID_DELETE_MAP_BUTTON
+	GUI_ID_DELETE_MAP_BUTTON,
+	GUI_ID_WORLD_LISTBOX,
 };
 
 struct MainMenuData
@@ -53,8 +55,9 @@ struct MainMenuData
 		// Server opts
 		creative_mode(false),
 		enable_damage(false),
+		selected_world(0),
 		// Actions
-		delete_map(false)
+		delete_world(false)
 	{}
 
 	// These are in the native format of the gui elements
@@ -71,8 +74,11 @@ struct MainMenuData
 	// Server options
 	bool creative_mode;
 	bool enable_damage;
+	int selected_world;
 	// If map deletion is requested, this is set to true
-	bool delete_map;
+	bool delete_world;
+
+	std::list<std::wstring> worlds;
 };
 
 class GUIMainMenu : public GUIModalMenu
diff --git a/src/main.cpp b/src/main.cpp
index 73469471..01c9b2c5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -972,60 +972,29 @@ int main(int argc, char *argv[])
 	if(port == 0)
 		port = 30000;
 	
-	// Map directory
-	std::string world_path = porting::path_user + DIR_DELIM + "server" + DIR_DELIM + "worlds" + DIR_DELIM + "world";
+	// World directory
+	std::string commanded_world = "";
 	if(cmd_args.exists("world"))
-		world_path = cmd_args.get("world");
+		commanded_world = cmd_args.get("world");
 	else if(cmd_args.exists("map-dir"))
-		world_path = cmd_args.get("map-dir");
+		commanded_world = cmd_args.get("map-dir");
 	else if(g_settings->exists("map-dir"))
-		world_path = g_settings->get("map-dir");
-	else{
-		// No map-dir option was specified.
-		// Check if the world is found from the default directory, and if
-		// not, see if the legacy world directory exists.
-		std::string legacy_world_path = porting::path_user+DIR_DELIM+".."+DIR_DELIM+"world";
-		if(!fs::PathExists(world_path) && fs::PathExists(legacy_world_path)){
-			errorstream<<"Warning: Using legacy world directory \""
-					<<legacy_world_path<<"\""<<std::endl;
-			world_path = legacy_world_path;
-		}
-	}
+		commanded_world = g_settings->get("map-dir");
 	
-	// Determine gameid
-	std::string gameid = "";
-	if(cmd_args.exists("gameid"))
-		gameid = cmd_args.get("gameid");
-	std::string world_gameid = getWorldGameId(world_path);
-	if(world_gameid == ""){
-		if(gameid != "")
-			world_gameid = gameid;
-		else{
-			world_gameid = "mesetint";
-		}
-	}
-	if(gameid == "")
-		gameid = world_gameid;
-	else if(world_gameid != ""){
-		if(world_gameid != gameid){
-			errorstream<<"World gameid mismatch"<<std::endl;
+	// Gamespec
+	SubgameSpec commanded_gamespec;
+	if(cmd_args.exists("gameid")){
+		std::string gameid = cmd_args.get("gameid");
+		commanded_gamespec = findSubgame(gameid);
+		if(!commanded_gamespec.isValid()){
+			errorstream<<"Game \""<<gameid<<"\" not found"<<std::endl;
 			return 1;
 		}
 	}
-	if(gameid == ""){
-		errorstream<<"No gameid supplied or detected"<<std::endl;
-		return 1;
-	}
-	
-	infostream<<"Using gameid \""<<gameid<<"\""<<std::endl;
 
-	SubgameSpec gamespec = findSubgame(gameid);
-	if(!gamespec.isValid()){
-		errorstream<<"Game \""<<gameid<<"\" not found"<<std::endl;
-		return 1;
-	}
-
-	// Run dedicated server if asked to or no other option
+	/*
+		Run dedicated server if asked to or no other option
+	*/
 #ifdef SERVER
 	bool run_dedicated_server = true;
 #else
@@ -1034,12 +1003,50 @@ int main(int argc, char *argv[])
 	if(run_dedicated_server)
 	{
 		DSTACK("Dedicated server branch");
-
 		// Create time getter if built with Irrlicht
 #ifndef SERVER
 		g_timegetter = new SimpleTimeGetter();
 #endif
+
+		// World directory
+		std::string world_path;
+		bool is_legacy_world = false;
+		if(commanded_world != ""){
+			world_path = commanded_world;
+		}
+		else{
+			// No specific world was commanded
+			// Check if the world is found from the default directory, and if
+			// not, see if the legacy world directory exists.
+			world_path = porting::path_user + DIR_DELIM + "server" + DIR_DELIM + "worlds" + DIR_DELIM + "world";
+			std::string legacy_world_path = porting::path_user+DIR_DELIM+".."+DIR_DELIM+"world";
+			if(!fs::PathExists(world_path) && fs::PathExists(legacy_world_path)){
+				errorstream<<"Warning: Using legacy world directory \""
+						<<legacy_world_path<<"\""<<std::endl;
+				world_path = legacy_world_path;
+				is_legacy_world = true;
+			}
+		}
+
+		// Gamespec
+		std::string world_gameid = getWorldGameId(world_path, is_legacy_world);
+		SubgameSpec gamespec = findSubgame(world_gameid);
+		if(commanded_gamespec.isValid() &&
+				commanded_gamespec.id != world_gameid){
+			errorstream<<"WARNING: Overriding gameid from \""
+					<<world_gameid<<"\" to \""
+					<<commanded_gamespec.id<<"\""<<std::endl;
+			gamespec = commanded_gamespec;
+		}
+
+		if(!gamespec.isValid()){
+			errorstream<<"Invalid gamespec. (world_gameid="
+					<<world_gameid<<")"<<std::endl;
+			return 1;
+		}
 		
+		infostream<<"Using gamespec \""<<gamespec.id<<"\""<<std::endl;
+
 		// Create server
 		Server server(world_path, configpath, gamespec);
 		server.start(port);
@@ -1181,6 +1188,8 @@ int main(int argc, char *argv[])
 	//skin->setColor(gui::EGDC_3D_SHADOW, video::SColor(0,0,0,0));
 	skin->setColor(gui::EGDC_3D_HIGH_LIGHT, video::SColor(255,0,0,0));
 	skin->setColor(gui::EGDC_3D_SHADOW, video::SColor(255,0,0,0));
+	skin->setColor(gui::EGDC_HIGH_LIGHT, video::SColor(255,70,100,50));
+	skin->setColor(gui::EGDC_HIGH_LIGHT_TEXT, video::SColor(255,255,255,255));
 	
 	/*
 		GUI stuff
@@ -1223,6 +1232,9 @@ int main(int argc, char *argv[])
 			guiroot = guienv->addStaticText(L"",
 					core::rect<s32>(0, 0, 10000, 10000));
 			
+			SubgameSpec gamespec;
+			WorldSpec worldspec;
+
 			/*
 				Out-of-game menu loop.
 
@@ -1246,14 +1258,34 @@ int main(int argc, char *argv[])
 				menudata.address = narrow_to_wide(address);
 				menudata.name = narrow_to_wide(playername);
 				menudata.port = narrow_to_wide(itos(port));
+				if(cmd_args.exists("password"))
+					menudata.password = narrow_to_wide(cmd_args.get("password"));
 				menudata.fancy_trees = g_settings->getBool("new_style_leaves");
 				menudata.smooth_lighting = g_settings->getBool("smooth_lighting");
 				menudata.clouds_3d = g_settings->getBool("enable_3d_clouds");
 				menudata.opaque_water = g_settings->getBool("opaque_water");
 				menudata.creative_mode = g_settings->getBool("creative_mode");
 				menudata.enable_damage = g_settings->getBool("enable_damage");
-				if(cmd_args.exists("password"))
-					menudata.password = narrow_to_wide(cmd_args.get("password"));
+				// Get world listing for the menu
+				std::vector<WorldSpec> worldspecs = getAvailableWorlds();
+				for(std::vector<WorldSpec>::const_iterator i = worldspecs.begin();
+						i != worldspecs.end(); i++)
+					menudata.worlds.push_back(narrow_to_wide(
+							i->name + " [" + i->gameid + "]"));
+				// Select if there is only one
+				if(worldspecs.size() == 1)
+					menudata.selected_world = 0;
+				else
+					menudata.selected_world = -1;
+				// If a world was commanded, append and select it
+				if(commanded_world != ""){
+					std::string gameid = getWorldGameId(commanded_world);
+					WorldSpec spec(commanded_world, "[commanded world]", gameid);
+					worldspecs.push_back(spec);
+					menudata.worlds.push_back(narrow_to_wide(spec.name)
+							+L" ["+narrow_to_wide(spec.gameid)+L"]");
+					menudata.selected_world = menudata.worlds.size()-1;
+				}
 
 				if(skip_main_menu == false)
 				{
@@ -1304,15 +1336,33 @@ int main(int argc, char *argv[])
 					infostream<<"Dropping main menu"<<std::endl;
 
 					menu->drop();
-					
-					// Delete map if requested
-					if(menudata.delete_map)
-					{
-						bool r = fs::RecursiveDeleteContent(world_path);
-						if(r == false)
-							error_message = L"Delete failed";
+				}
+
+				// Set world path to selected one
+				if(menudata.selected_world != -1){
+					worldspec = worldspecs[menudata.selected_world];
+					infostream<<"Selected world: "<<worldspec.name
+							<<" ["<<worldspec.path<<"]"<<std::endl;
+				}
+				
+				// Delete map if requested
+				if(menudata.delete_world)
+				{
+					if(menudata.selected_world == -1){
+						error_message = L"Cannot delete world: "
+								L"no world selected";
+						errorstream<<wide_to_narrow(error_message)<<std::endl;
 						continue;
 					}
+					/*bool r = fs::RecursiveDeleteContent(worldspec.path);
+					if(r == false){
+						error_message = L"World delete failed";
+						errorstream<<wide_to_narrow(error_message)<<std::endl;
+					}*/
+					// TODO: Some kind of a yes/no dialog is needed.
+					error_message = L"This doesn't do anything currently.";
+					errorstream<<wide_to_narrow(error_message)<<std::endl;
+					continue;
 				}
 
 				playername = wide_to_narrow(menudata.name);
@@ -1336,7 +1386,40 @@ int main(int argc, char *argv[])
 				// Update configuration file
 				if(configpath != "")
 					g_settings->updateConfigFile(configpath.c_str());
-			
+				
+				// If local game
+				if(address == "")
+				{
+					if(menudata.selected_world == -1){
+						error_message = L"No world selected and no address "
+								L"provided. Nothing to do.";
+						errorstream<<wide_to_narrow(error_message)<<std::endl;
+						continue;
+					}
+					// Load gamespec for required game
+					gamespec = findSubgame(worldspec.gameid);
+					if(!gamespec.isValid() && !commanded_gamespec.isValid()){
+						error_message = L"Could not find or load game \""
+								+ narrow_to_wide(worldspec.gameid) + L"\"";
+						errorstream<<wide_to_narrow(error_message)<<std::endl;
+						continue;
+					}
+					if(commanded_gamespec.isValid() &&
+							commanded_gamespec.id != worldspec.gameid){
+						errorstream<<"WARNING: Overriding gamespec from \""
+								<<worldspec.gameid<<"\" to \""
+								<<commanded_gamespec.id<<"\""<<std::endl;
+						gamespec = commanded_gamespec;
+					}
+
+					if(!gamespec.isValid()){
+						error_message = L"Invalid gamespec. (world_gameid="
+								+narrow_to_wide(worldspec.gameid)+L")";
+						errorstream<<wide_to_narrow(error_message)<<std::endl;
+						continue;
+					}
+				}
+
 				// Continue to game
 				break;
 			}
@@ -1354,7 +1437,7 @@ int main(int argc, char *argv[])
 				input,
 				device,
 				font,
-				world_path,
+				worldspec.path,
 				playername,
 				password,
 				address,
@@ -1368,13 +1451,13 @@ int main(int argc, char *argv[])
 		} //try
 		catch(con::PeerNotFoundException &e)
 		{
-			errorstream<<"Connection error (timed out?)"<<std::endl;
 			error_message = L"Connection error (timed out?)";
+			errorstream<<wide_to_narrow(error_message)<<std::endl;
 		}
-		catch(SocketException &e)
+		catch(ServerError &e)
 		{
-			errorstream<<"Socket error (port already in use?)"<<std::endl;
-			error_message = L"Socket error (port already in use?)";
+			error_message = narrow_to_wide(e.what());
+			errorstream<<wide_to_narrow(error_message)<<std::endl;
 		}
 		catch(ModError &e)
 		{
diff --git a/src/subgame.cpp b/src/subgame.cpp
index ed50d09a..2fa3b794 100644
--- a/src/subgame.cpp
+++ b/src/subgame.cpp
@@ -21,6 +21,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "porting.h"
 #include "filesys.h"
 #include "settings.h"
+#include "log.h"
 
 SubgameSpec findSubgame(const std::string &id)
 {
@@ -68,15 +69,67 @@ std::set<std::string> getAvailableGameIds()
 	return gameids;
 }
 
-std::string getWorldGameId(const std::string &world_path)
+#define LEGACY_GAMEID "mesetint"
+
+std::string getWorldGameId(const std::string &world_path, bool can_be_legacy)
 {
 	std::string conf_path = world_path + DIR_DELIM + "world.mt";
 	Settings conf;
 	bool succeeded = conf.readConfigFile(conf_path.c_str());
-	if(!succeeded)
+	if(!succeeded){
+		if(can_be_legacy){
+			// If map_meta.txt exists, it is probably an old minetest world
+			if(fs::PathExists(world_path + DIR_DELIM + "map_meta.txt"))
+				return LEGACY_GAMEID;
+		}
 		return "";
+	}
 	if(!conf.exists("gameid"))
 		return "";
 	return conf.get("gameid");
 }
 
+std::vector<WorldSpec> getAvailableWorlds()
+{
+	std::vector<WorldSpec> worlds;
+	std::set<std::string> worldspaths;
+	worldspaths.insert(porting::path_user + DIR_DELIM + "server"
+			+ DIR_DELIM + "worlds");
+	infostream<<"Searching worlds..."<<std::endl;
+	for(std::set<std::string>::const_iterator i = worldspaths.begin();
+			i != worldspaths.end(); i++){
+		infostream<<"  In "<<(*i)<<": "<<std::endl;
+		std::vector<fs::DirListNode> dirvector = fs::GetDirListing(*i);
+		for(u32 j=0; j<dirvector.size(); j++){
+			if(!dirvector[j].dir)
+				continue;
+			std::string fullpath = *i + DIR_DELIM + dirvector[j].name;
+			std::string name = dirvector[j].name;
+			std::string gameid = getWorldGameId(fullpath);
+			WorldSpec spec(fullpath, name, gameid);
+			if(!spec.isValid()){
+				infostream<<"(invalid: "<<name<<") ";
+			} else {
+				infostream<<name<<" ";
+				worlds.push_back(spec);
+			}
+		}
+		infostream<<std::endl;
+	}
+	// Check old world location
+	do{
+		std::string fullpath = porting::path_user + DIR_DELIM + ".."
+				+ DIR_DELIM + "world";
+		if(!fs::PathExists(fullpath))
+			break;
+		std::string name = "Old World";
+		std::string gameid = getWorldGameId(fullpath, true);
+		WorldSpec spec(fullpath, name, gameid);
+		infostream<<"Old world found."<<std::endl;
+		worlds.push_back(spec);
+	}while(0);
+	infostream<<worlds.size()<<" found."<<std::endl;
+	return worlds;
+}
+
+
diff --git a/src/subgame.h b/src/subgame.h
index ba2f235e..1daeb8b1 100644
--- a/src/subgame.h
+++ b/src/subgame.h
@@ -22,6 +22,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include <string>
 #include <set>
+#include <vector>
 
 struct SubgameSpec
 {
@@ -47,7 +48,32 @@ SubgameSpec findSubgame(const std::string &id);
 
 std::set<std::string> getAvailableGameIds();
 
-std::string getWorldGameId(const std::string &world_path);
+std::string getWorldGameId(const std::string &world_path,
+		bool can_be_legacy=false);
+
+struct WorldSpec
+{
+	std::string path;
+	std::string name;
+	std::string gameid;
+
+	WorldSpec(
+		const std::string &path_="",
+		const std::string &name_="",
+		const std::string &gameid_=""
+	):
+		path(path_),
+		name(name_),
+		gameid(gameid_)
+	{}
+
+	bool isValid() const
+	{
+		return (name != "" && path != "" && gameid != "");
+	}
+};
+
+std::vector<WorldSpec> getAvailableWorlds();
 
 #endif
 
-- 
2.30.2