Game NPC multi-action lua script design

Question

I need to put scriptable NPC in my currect game project. The project itself is developed in C++ language. I will using Luabind to bind lua and c++.

I need to call NPC function when certain NPC clicked or timer to do something is activated. Currently I stuck between 2 NPC script design.

1. Using a kind of npcname_action to differentiate every NPC.
   This is kind of troublesome to give name to every different NPC.
   I'm still thinking how to implement this in my project.
   Example:

   HotelBellboy12_Click() { .. }  
   HotelBellboy12_TimerAction() { .. }
   

2. Using name of function.
   Every npc have it own lua file.
   I'm thinking to load script into memory and when needed will be loaded into luaState using luaL_loadbuffer
   Example:

   OnClick() { .. }
   OnTimerAction() { .. }
   

Which one is better and why?

Answer 1

I've done something like this before and I used something similar to your #2 option. When the map loads I load a configuration Lua file containing all the NPC data; among that is the name of the script file used for the NPC.

When I need to load the NPC in the game I compile the Lua file. NPC's can use a 'model' NPC type to dictate most of the common behavior (for example a Merchant type or a Commoner type) which is specified in the NPC configuration. These model types provide all the basic functionality such as providing a trade window when clicked. The specific NPC's use functions like OnClick() to override their model and provide custom handlers.

This worked pretty well for me, although it ends up being a large volume of scripts if your game gets large.