Add Support for applying a PNG Static Resource to a Map Item

[diamonddevv]

Apply an image loaded as a static resource to a map item. Not too sure how to tackle this.

[MulverineX]

The maps protocol works like this: each map has an integer id, and when a client receives this ID in the item data (1.20.5+ minecraft:map_id), it requests the map data from the server. The server responds with NBT that lists every pixel and its RGB value.

Here's what Luafy needs to extend:

• Luafy.create_map_image, this method will return a symbolic script object for unique map integer IDs, (starting at 1,000,000 to avoid collisions), that you can then access with MapScriptObject.ids (an ordered list) & width / height. This method will also have an option to scale the image with either bilinear or nearest neighbor, defaulting to converting the entire image. Internally, Luafy will:
  • hash the static resource
  • convert the static resource into map nbt
  • store the map nbt along with the static resource hash & path
  • on reload/restart, if the static resource hash hasn't changed, don't reconvert, and if there's an orphaned map image, delete it
  • capture client requests for map IDs over 1mil, respond with the cached data (probably keep it loaded in memory until reload after create_map_data is called or the client requests it)

Prior Art: an external tool (some of the relevant code here), a server mod by Patbox