chunkgen

A Rust library for generating Minecraft worlds. It reads vanilla and custom datapacks, JIT-compiles their density functions, and generates chunks that match vanilla's output.

Status

This project is in a very experimental state. The API is not stable and is subject to change.

Generation runs through ChunkStatus::Features. InitializeLight, Light, Spawn, and Full are not implemented and return Error::Unsupported.

Features

• Loads worldgen from a datapack directory or .zip, layered over vanilla data
• Density functions JIT-compiled to native code with Cranelift
• Biomes, noise, surface rules, carvers, features, and structures
• Overworld, nether, and end, plus datapack-defined dimensions
• Parallel chunk generation on a Rayon pool
• World presets (e.g. amplified, large biomes)

Installation

This crate requires a nightly toolchain, since it uses portable_simd and several const trait features. The pinned version is in rust-toolchain.toml.

[dependencies]
chunkgen = "0.2.0"

Usage

use chunkgen::{ChunkPos, ChunkStatus, WorldgenBuilder};

let worldgen = WorldgenBuilder::new()
    .with_seed(42)
    .build()
    .expect("failed to build worldgen");

let top = worldgen
    .generate(ChunkPos::new(0, 0), ChunkStatus::Features, |view| {
        view.get_relative_block(0, (view.height() - 1) as usize, 0)
    })
    .expect("failed to generate chunk");

generate takes a closure rather than returning the chunk, so the chunk data is read under the store's lock and never copied out wholesale. ChunkView exposes block and biome lookups, the dimension's min_y and height, and iterators over both.

To use a custom datapack, layer it over the built-in one:

use chunkgen::{WorldgenBuilder, datapack::Datapack};

let datapack = Datapack::zip("Terralith.zip")
    .expect("failed to load Terralith datapack")
    .layered_over(Datapack::builtin());

let worldgen = WorldgenBuilder::new()
    .with_seed(42)
    .with_datapack(datapack)
    .build()
    .expect("failed to build worldgen");

Examples

The examples use shulkr to start a real server you can join.

cargo r -r --example vanilla
cargo r -r --example datapack <datapack.zip|directory> [dimension]

There are also examples for every world preset:

cargo r -r --example flat_world [water_world|tunnelers_dream|the_void|...]
cargo r -r --example debug_world
cargo r -r --example amplified
cargo r -r --example large_biomes
cargo r -r --example single_biome [biome]

Roadmap

• Structure starts and references
• Biomes
• Noise
• Surface rules
• Carvers
• Features
• Datapack loading (directory and .zip, layered)
• JIT-compiled density functions
• Structures, including jigsaw assembly
• Overworld, nether, and end, plus datapack-defined dimensions
• Parallel chunk generation
• Lighting
• Loot tables
• Entity spawning
• Performance improvements

License

This project is licensed under Apache-2.0.