spatial_codec_draco

A small, robust wrapper around the upstream Draco point-cloud codec.

This crate vendors Draco as a git submodule (./draco/), builds a minimal C++ wrapper (./draco_wrapper_cpp/), and exposes:

• a safe Rust API for encoding/decoding point clouds, and
• an optional C ABI (generated header) for C/C++ (and other languages) to stay layout-compatible.

Documentation

• Design notes and rationale: docs/design.md
• C ABI types + memory/ownership rules: docs/ffi.md

Prerequisites

You typically only need:

• CMake
• a C++17 compiler toolchain
• (optional) Ninja as a faster CMake generator

For Windows cross-compilation from Linux, MinGW-w64 is commonly used.

Getting started

Make sure the Draco submodule is present:

git submodule update --init --recursive

Build:

cargo build

Rust usage

use spatial_codec_draco::{decode_draco, encode_draco, EncodeConfig, PointCloudEncodingMethod};

let coords: Vec<[f32; 3]> = vec![[0.0, 0.0, 0.0], [1.0, 0.0, 0.0]];
let colors: Vec<[u8; 3]> = vec![[255, 0, 0], [0, 255, 0]];

// Convenience: uses `EncodeConfig::default()`.
let encoded = encode_draco(&coords, &colors, PointCloudEncodingMethod::KdTree)?;

// Configurable: control quantization and speed/size tradeoffs.
let cfg = EncodeConfig {
    position_quantization_bits: 12,
    color_quantization_bits: 8,
    encoding_speed: 5,
    decoding_speed: 5,
};
let encoded = spatial_codec_draco::encode_draco_with_config(
    &coords,
    &colors,
    PointCloudEncodingMethod::KdTree,
    &cfg,
)?;

let (decoded_coords, decoded_colors) = decode_draco(&encoded)?;
# Ok::<(), Box<dyn std::error::Error>>(())

C ABI

When the ffi feature is enabled (default), the build produces a header at:

• bindings/spatial_codec_draco.h

This header exposes only layout-stable (#[repr(C)]) types and avoids Rust-specific ownership types (e.g. Vec, Box, String) across ABI boundaries. External projects are encouraged to base their native-side type definitions directly on this header to remain compatible.

See docs/ffi.md for the exact API, error handling, and memory rules.

Examples

• Combine multiple folders of Draco frames into a single stream:

cargo run --example combine_folders -- --help