add room destroy function

main.lua

@@ -121,6 +121,7 @@ function gotoRoom(room_type, ...)
     if type(Class) ~= "table" and type(Class) ~= "function" then
         error("room '"..room_type.."' is not callable (got "..type(Class)..", does room return itself?)")
     end
+    if current_room and current_room.destroy then current_room:destroy() end
     current_room = _G[room_type](...)
 end
 

obj/Room.lua

@@ -46,4 +46,10 @@ function Room:canvasDraw()
     self.area:draw()
 end
 
+---Destroys room
+function Room:destroy()
+    self.area:destroy()
+    self.area = nil
+end
+
 return Room