draco_decoder

draco_decoder is a Rust library for decoding Draco compressed meshes. It provides native and WebAssembly (WASM) support with efficient bindings to the official Draco C++ library.

Overview

• Native:
  The native part uses cxx to create safe and ergonomic FFI bindings that directly connect to Draco's C++ decoding library. This allows efficient and zero-copy mesh decoding in native environments.

• WASM:
  For WebAssembly targets, draco_decoder leverages the official Draco Emscripten build. It uses a JavaScript Worker to run the Draco decoder asynchronously, enabling non-blocking mesh decoding in the browser. The JavaScript implementation is available in a separate repository:
  https://github.com/jiangheng90/draco_decoder_js.git

This design provides a unified Rust API while seamlessly switching between native and WASM implementations under the hood.

build guide

• install essential for draco build
• cargo build

⚠️ Warning: This crate currently work in progress, I have not tested on many devices of building. now on windows it only support build on MSVC, and it may have some build issues.

native/wasm usage

use draco_decoder::{DracoDecodeConfig, AttributeDataType, decode_mesh};

// some async wrapper

let mut config = DracoDecodeConfig::new(vertex_count, index_count);

// Add attributes to decode (dimention and data type)
config.add_attribute(dim, AttributeDataType::Float32);
config.add_attribute(dim, AttributeDataType::Float32);

// Your Draco-encoded binary mesh data
let data: &[u8] = /* your Draco encoded data here */;

// Asynchronously decode the mesh data
let buf = decode_mesh(data, &config).await;

// for native user, you can use sync function
 let buf = decode_mesh_sync(data, &config)

// wrapper end

Performance

The performance of draco_decoder has been measured under different environments:

Environment	Typical Decoding Time
Native (Release Build)	3 ms – 7 ms
WebAssembly (WASM)	30 ms – 50 ms