Maps.md

Loading and Unloading

A major problem with [[OpenNefia-LÖVE]]'s design was the fact that there was no central store for tracking loaded maps. This meant that a map loaded twice from disk would reference two separate copies of the same map, which became a headache when the same map needed updates in multiple places.

See issue #205.

local map_uid = 1
local ok, map1 = Map.load(map_uid)
local ok, map2 = Map.load(map_uid)
assert(map1 == map2) -- fails

In OpenNefia.NET, there will be some kind of global store that will manage maps. Maps will not be saved or loaded individually anymore, only when they're being managed as part of a game save. A map can still be instantiated as a standalone object, but it cannot be set as the active map until the map storage is tracking it.

Map Transactions

For simplicity's sake, editing a map that isn't the current one could be handled with a "transaction" system.

You can specify a closure with logic to run on the loaded map, and the map is modified and saved back to disk in a single transaction.

var mapId = 14;
MapLoader.EditMap(mapId, (map) => map.Clear(TileDefOf.Grass));

This would take care of multiple concurrent mutations, where the map currently being edited in memory is passed by MapLoader if EditMap is inadvertently called twice on the same map.

Then you could call MapLoader.FlushPendingTransactions() at some point to run all the closures in sequence.