FastNBT is a serde serializer and deserializer for
Minecraft: Java Edition's NBT format, including
Value type and
nbt! macro. For
stringified NBT (sNBT) see FastSNBT.
FastAnvil allows rendering maps of worlds, and a
Region for
using the Region file format. Supports 1.20 down to 1.13 inclusive, and slightly
flaky support for 1.12.
An in-browser Rust-to-WASM powered Minecraft map renderer demo is below.
Demo of Hermitcraft season 8 and more at owengage.com/anvil
The anvil binary from fastnbt-tools can render your world leveraging all of
your CPU.
A bunch of examples can be found in
fastnbt/examples,
fastanvil/examples and tools/src. Some examples are recreated below.
The following edits the world spawn to 250, 200, 250 (probably not a good idea!). Full example in fastnbt/examples directory.
#[derive(Serialize, Deserialize)]
struct LevelDat {
#[serde(rename = "Data")]
data: Data,
}
#[derive(Serialize, Deserialize)]
#[serde(rename_all = "PascalCase")]
struct Data {
spawn_x: i32,
spawn_y: i32,
spawn_z: i32,
#[serde(flatten)]
other: HashMap<String, Value>,
}
fn main() {
let args: Vec<_> = std::env::args_os().collect();
let file = std::fs::File::open(&args[1]).unwrap();
let mut decoder = GzDecoder::new(file);
let mut bytes = vec![];
decoder.read_to_end(&mut bytes).unwrap();
let mut leveldat: LevelDat = fastnbt::from_bytes(&bytes).unwrap();
leveldat.data.spawn_x = 250;
leveldat.data.spawn_y = 200;
leveldat.data.spawn_z = 250;
let new_bytes = fastnbt::to_bytes(&leveldat).unwrap();
let outfile = std::fs::File::create("level.dat").unwrap();
let mut encoder = GzEncoder::new(outfile, Compression::fast());
encoder.write_all(&new_bytes).unwrap();
}This example demonstrates printing out a players inventory and ender chest contents from the player dat files found in worlds. We
- use serde's renaming attribute to have rustfmt conformant field names,
- use lifetimes to save on string allocations, and
- use the
Valuetype to deserialize a field we don't specify the exact structure of.
#[derive(Deserialize, Debug)]
#[serde(rename_all = "PascalCase")]
struct PlayerDat<'a> {
data_version: i32,
#[serde(borrow)]
inventory: Vec<InventorySlot<'a>>,
ender_items: Vec<InventorySlot<'a>>,
}
#[derive(Deserialize, Debug)]
struct InventorySlot<'a> {
id: &'a str, // We avoid allocating a string here.
tag: Option<Value>, // Also get the less structured properties of the object.
// We need to rename fields a lot.
#[serde(rename = "Count")]
count: i8,
}
fn main() {
let args: Vec<_> = std::env::args().skip(1).collect();
let file = std::fs::File::open(args[0].clone()).unwrap();
// Player dat files are compressed with GZip.
let mut decoder = GzDecoder::new(file);
let mut data = vec![];
decoder.read_to_end(&mut data).unwrap();
let player: Result<PlayerDat> = from_bytes(data.as_slice());
println!("{:#?}", player);
}For the libraries
[dependencies]
fastnbt = "2"
fastanvil = "0.32"For the anvil executable
cargo install fastnbt-tools