Add basic gamestate API

mods/lzr_gamestate/init.lua

@@ -1,10 +1,46 @@
 lzr_gamestate = {}
 
 -- List of game states
-lzr_gamestate.MENU = 1		-- When in the main menu
-lzr_gamestate.LEVEL = 2		-- When playing a level
-lzr_gamestate.EDITOR = 3	-- TODO: When making a level in the level editor
+lzr_gamestate.MENU = 1			-- When in the main menu
+lzr_gamestate.LEVEL = 2			-- When playing a level
+lzr_gamestate.LEVEL_COMPLETE = 3	-- When a level was won and waiting for the next level
+lzr_gamestate.EDITOR = 4		-- TODO: When making a level in the level editor
 
 -- Always start at the MENU state
-lzr_gamestate.state = lzr_gamestate.MENU
+local current_state = lzr_gamestate.MENU
 
+-- Registered callbacks
+lzr_gamestate.registered_on_enter_states = {}
+lzr_gamestate.registered_on_exit_states = {}
+
+------------
+-- API calls
+------------
+
+lzr_gamestate.set_state = function(new_state)
+	local state_changed = current_state ~= new_state
+	local old_state = current_state
+
+	if state_changed then
+		for _, callback in pairs(lzr_gamestate.registered_on_enter_states) do
+			callback(new_state)
+		end
+		for _, callback in pairs(lzr_gamestate.registered_on_exit_states) do
+			callback(old_state)
+		end
+	end
+
+	current_state = new_state
+end
+
+lzr_gamestate.get_state = function()
+	return current_state
+end
+
+lzr_gamestate.register_on_enter_state = function(callback)
+	table.insert(lzr_gamestate.registered_on_enter_states, callback)
+end
+
+lzr_gamestate.register_on_exit_state = function(callback)
+	table.insert(lzr_gamestate.registered_on_exit_states, callback)
+end

mods/lzr_levels/init.lua

@@ -91,7 +91,7 @@ function lzr_levels.start_level(level)
 	player:set_pos({x=5,y=2,z=5})
 	lzr_levels.prepare_and_build_level(level)
 	lzr_messages.show_message(player, S("Level @1", level), 3)
-	lzr_gamestate.state = lzr_gamestate.LEVEL
+	lzr_gamestate.set_state(lzr_gamestate.LEVEL)
 end
 
 function lzr_levels.next_level()
@@ -109,7 +109,7 @@ function lzr_levels.leave_level()
 	current_level = nil
 	clear_inventory(player)
 	player:set_pos(vector.add(lzr_globals.MENU_SHIP_POS, lzr_globals.MENU_SHIP_PLAYER_SPAWN_OFFSET))
-	lzr_gamestate.state = lzr_gamestate.MENU
+	lzr_gamestate.set_state(lzr_gamestate.MENU)
 end
 
 minetest.register_chatcommand("level", {
@@ -135,7 +135,7 @@ minetest.register_chatcommand("restart", {
 	params = "",
 	description = S("Restart current level"),
 	func = function(name, param)
-		if lzr_gamestate.state == lzr_gamestate.LEVEL then
+		if lzr_gamestate.get_state() == lzr_gamestate.LEVEL then
 			lzr_levels.start_level(current_level)
 			return true
 		else
@@ -149,7 +149,7 @@ minetest.register_chatcommand("leave", {
 	params = "",
 	description = S("Leave current level"),
 	func = function(name, param)
-		if lzr_gamestate.state == lzr_gamestate.LEVEL then
+		if lzr_gamestate.get_state() == lzr_gamestate.LEVEL then
 			lzr_levels.leave_level(current_level)
 			return true
 		else