Map Sync Table

Share explored map areas with everyone on your server, using Xaero's World Map.

Build a Map Sync Table and right-click it. Your explored areas are uploaded to the server, and you get back everything the other players have explored. They get yours the next time they use a table.

This mod is independent and not affiliated with Xaero. It requires Xaero's World Map on every client that wants to share.

How to use

1. Craft a Map Sync Table.
2. Place it and right-click it. (Sneak + right-click ignores the table, so you can still build against it.)
3. Open your map again (default key M) so the new areas are drawn.

Recipe

Requirements

• Minecraft 1.21.10 with NeoForge 21.10.64
• A dedicated server
• Xaero's World Map on each client that wants to share. Xaero's World Map does not need to be installed on the server.
• This mod on the server and on every client that wants to share, all on the same version.

How it works

1. Your client sends the server a short list of the map region files it has, with a fingerprint of each.
2. The server compares it with its shared map bank and only transfers files that are new or changed, in both directions.
3. Received regions are merged chunk by chunk (the union of what has been explored), so nobody loses anything. The map cache is cleared so Xaero redraws the map.

The shared bank lives in <world>/xaerokartdeling/maps/ on the server.

Things to know

• Only the map region files are shared, nothing else.
• The mod reads and writes Xaero's region.xaero files, and asks Xaero's World Map to reload by calling into its internal classes. It does not include any of Xaero's code. If a future Xaero update changes those internals, the reload step may stop working until this mod is updated. Until then, reopening the map is the fallback.
• It has been used by two players on a real server. It has not been tested with large groups.

License

MIT. Source code is not public yet.