Crate lumen 

A reference implementation of the LUMEN print file format, version 1.0.

LUMEN is the Open Resin Alliance’s resin (MSLA) print format; the normative specification lives beside this crate, in spec/. This crate is a consumer of that text, not a substitute for it: where the specification and this code disagree, the specification wins, and the conformance corpus under test-vectors/ is what settles the argument.

Shape

• container - the file header, chunk directory and trailer.
• chunks - one codec per chunk type.
• json - the typed META, PROF and LROV models.
• ree - run-end encoded layer masks: binary, grayscale and split.
• timing - the per-layer settings pipeline of section 8.
• crypto - AUTH, the AEAD units, Argon2id and X25519 key wrapping.
• validate - the checks of section 11, named as the corpus names them.
• reader - reader::LumenFile, including random access to one layer.
• writer - writer::Encoder, which produces a conforming file.

Reading

use lumen::{reader::LumenFile, validate::Level};

let bytes = std::fs::read("print.lumen").unwrap();
let file = LumenFile::open(&bytes, Level::Loose).unwrap();
println!("{} layers", file.layer_count());
let layer = file.layer(0).unwrap();
println!("{:?}", layer.tag);

Two tiers

reader::LumenFile decodes what a caller asks for and nothing else: a layer is fetched by index, which decompresses only the LAYR chunk that holds it. A firmware reader can open the file, read META and the layer table, and stream layers through a fixed-size buffer without ever materializing the whole file. A slicer can instead use writer::Encoder, which trains the zstd dictionary, frames the chunks and assembles the directory.

Re-exports

pub use check::Check;

pub use container::ChunkDescriptor;

pub use container::ChunkType;

pub use container::Directory;

pub use container::FileHeader;

pub use error::Error;

pub use error::Result;

pub use json::Material;

pub use json::Meta;

pub use json::Profile;

pub use json::Sector;

pub use json::Timing;

pub use reader::LumenFile;

pub use ree::DecodedLayer;

pub use ree::EncodeMode;

pub use validate::Level;

pub use validate::Validator;

pub use writer::Encoder;

Modules

check

The named conformance checks.

chunks

One codec per chunk type ([spec/03-chunks.md], [spec/09-layer-data.md], [spec/10-scene-chunks.md]).

container

The container: 32-byte file header, 32-byte chunk descriptors, the directory at the end of the file, and the 8-byte trailer ([spec/02-file-structure.md]).

crypto

Authenticated encryption: the AUTH chunk, the AEAD units, Argon2id password wrapping and X25519 machine binding ([spec/15-encryption.md]).

error

The crate’s single error type, carrying the conformance check that failed.

io

Little-endian, bounds-checked byte reading and writing.

json

Typed models for the JSON chunks: META (with its sectors entries), PROF and LROV.

reader

Reading a file: LumenFile, including random access to one layer.

ree

Run-end encoded layer masks ([spec/11-layer-encoding.md] section 5).

timing

The per-layer settings pipeline ([spec/14-layer-timing.md] section 8).

validate

The checks of [spec/17-validation.md] section 11.

varint

Protocol-Buffers-style varints ([spec/11-layer-encoding.md] section 5.2).

writer

Writing a file: Encoder, which assembles a conforming .lumen container.