On Demand Room System
Problem: You have an ASCII/ANSI based MOO that represents many rooms graphically, often. Storing an object for each room consumes database space. Database space is loaded into RAM at a cost of approx. (object's size in bytes) * 2. On Wayfar, with 9 planets at 100x100, this would be nearly 10,000 objects per planet, almost 100,000 objects just to store blank space.
Solution: Only store the rooms that players or other objects are using. Procedurally generate other rooms as required. The savings are huge! This is a rough guide to implementing such a system in MOO. There will be a lot of variation based on your specific gameworld.
Step 1: Track spawned rooms and delete unused space.
On Wayfar, an object named $ods (on demand spawn) is used to track the status of spawned rooms. The active rooms are stored in a hash property called spawned_rooms.
Each room must have a unique identifier for easy tracking. I did this by creating a verb to concatenate a string together from the room's planet/location, and x, y, z co-ordinates. Example:
$ods:key_string(OBJ room)
room = args[1];
key = tostr(room.location, "-", room.x, "-", room.y,"-", room.z);
return key;
This would return a string along these lines: #4444-1-3--1 for a room located in object #4444 at 1, 3, -1. This key will let you refer to the active rooms in $ods.spawned_rooms easily.
Next we create a spawning verb for getting the rooms. This part varies heavily according to how your rooms are setup, and how they are generated. On Wayfar, we use a simple biome grid generated at planetary creation. We always know the terrain type for a given X, Y location on a planet, and from that we can generate the appropriate resources and creatures. This could be improved by proceduralizing all aspects of the room, so that even a despawned room would be re-created exactly from spawn to spawn. Rough example:
$ods:spawn_3d_room(OBJ location, INT x, INT y, INT z)
{planet, x, y, z} = args;room_key = $ods:key_string(planet,x,y,z);"if the room already exists, we can just return it";if(room_key in keys($ods.spawned_rooms)) room = $ods.spawned_rooms[room_key]; if(gamevalid(room) && is_a(room,$room)) return room; endifendif"otherwise, we should create a new room and return that";
room = $room:populate();
"on hellcore, that might be: room = $rpg:spawn($room)";
room:set_point(x, y, z);
room:moveto(planet);
$ods.spawned_rooms[room_key] = room;
Now we need to clean up unused rooms. Example:
$halfhourly:clean_ods
rooms = $ou:leaves_suspended($room);
for r in (rooms)
yield;
if(length(r.contents) < 1)
"you could also add, as we have on Wayfar, a timer check to keep rooms persistent for some period of time";
$rpg:junk(r);
endif
endfor
Important note: Once the elements above are implemented for your system, you still need to hook them into the actual movement actions for the player. I setup some vector based verbs to figure out the rooms I need to be spawning based on the direction the player is moving (on a planet a player can move in any cardinal direction).
This guide will hopefully be expanded as time goes on and I am able to write more examples.
