geodesk-rs

Rust bindings for the GeoDESK C++ library using cxx.rs.

GeoDESK is a fast and efficient library for querying OpenStreetMap data from GOL (Geographic Object Library) files. This crate provides safe Rust bindings to the GeoDESK C++ API, allowing you to query OSM features using GOQL (Geographic Object Query Language).

Features

• 🚀 Fast queries of OpenStreetMap data
• 🗺️ Support for GOQL (Geographic Object Query Language)
• 📦 Query features by type, tags, and bounding box
• 🔍 Built-in convenience methods for common queries (restaurants, roads, bus stops, etc.)
• 🦀 Safe Rust API with zero-cost abstractions
• 🔗 Direct bindings to C++ for maximum performance

Prerequisites

This library automatically downloads and builds GeoDESK using CMake's FetchContent feature! You only need:

1. CMake 3.14 or higher

   • Linux: sudo apt install cmake (Debian/Ubuntu) or sudo yum install cmake (RHEL/CentOS)
   • macOS: brew install cmake
   • Windows: Download from https://cmake.org/download/

2. C++20 compatible compiler

   • GCC 10+, Clang 11+, or MSVC 2019+

3. A GOL file containing OpenStreetMap data

   • Build using the gol command-line tool:

     gol build world planet-latest.osm.pbf

   • Or download pre-built GOL files from GeoDESK

That's it! No need to manually install GeoDESK - it's fetched automatically during build.

Installation

Add this to your Cargo.toml:

[dependencies]
geodesk-rs = "0.1.0"

The first build will take a few minutes as CMake downloads and compiles GeoDESK. Subsequent builds will be much faster.

Quick Start

use geodesk_rs::{GeoDesk, BoundingBox};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Open a GOL file
    let geodesk = GeoDesk::open("world.gol")?;

    // Define a bounding box for Montreal, Quebec
    let bbox = BoundingBox::new(-73.9781, 45.4042, -73.4766, 45.7042);

    // Query restaurants
    let restaurants = geodesk.query_amenities("restaurant", bbox)?;
    println!("Found {} restaurants", restaurants.count());

    // Get results as a vector
    let features = restaurants.to_vec()?;
    for restaurant in features.iter().take(5) {
        println!("- {} at ({:.4}, {:.4})",
            restaurant.name, restaurant.lon, restaurant.lat);
    }

    Ok(())
}

Usage Examples

Query Amenities by Type

let bbox = BoundingBox::new(-73.9, 45.4, -73.5, 45.7);

// Query specific amenity types
let restaurants = geodesk.query_amenities("restaurant", bbox)?;
let cafes = geodesk.query_amenities("cafe", bbox)?;
let hotels = geodesk.query_amenities("hotel", bbox)?;

// Or use convenience methods
let restaurants = geodesk.query_restaurants(bbox)?;
let cafes = geodesk.query_cafes(bbox)?;
let bars = geodesk.query_bars(bbox)?;

Query Roads and Transportation

let copenhagen = BoundingBox::new(12.45, 55.61, 12.65, 55.73);

// Query all roads
let roads = geodesk.query_roads(copenhagen)?;

// Query bus stops
let bus_stops = geodesk.query_bus_stops(copenhagen)?;

// Query specific road types using GOQL
let motorways = geodesk.query("w[highway=motorway]", copenhagen)?;
let residential = geodesk.query("w[highway=residential]", copenhagen)?;

Custom GOQL Queries

GOQL (Geographic Object Query Language) allows powerful filtering:

// Multiple amenity types
let food = geodesk.query("na[amenity=restaurant,cafe,bar]", bbox)?;

// Parks
let parks = geodesk.query("a[leisure=park]", bbox)?;

// Schools
let schools = geodesk.query("na[amenity=school]", bbox)?;

// Water features
let water = geodesk.query("wa[natural=water,waterway]", bbox)?;

// Traffic signals
let signals = geodesk.query("n[highway=traffic_signals]", bbox)?;

Working with Results

let results = geodesk.query_restaurants(bbox)?;

// Get count
println!("Found {} restaurants", results.count());

// Check if empty
if results.is_empty() {
    println!("No results found");
}

// Convert to vector and iterate
let features = results.to_vec()?;
for feature in features {
    println!("Name: {}", feature.name);
    println!("Location: ({}, {})", feature.lon, feature.lat);
    println!("Type: {}", feature.type_name);

    // Access tags
    if let Some(cuisine) = feature.tag("cuisine") {
        println!("Cuisine: {}", cuisine);
    }

    // Check if tag exists
    if feature.has_tag("wheelchair") {
        println!("Wheelchair accessible");
    }
}

Bounding Box Creation

// Create from explicit coordinates (West, South, East, North)
let bbox = BoundingBox::new(-73.9, 45.4, -73.5, 45.7);

// Create from center point and radius
let bbox = BoundingBox::from_center(-73.7, 45.5, 0.2); // 0.2 degrees radius

GOQL Query Syntax

GeoDESK uses GOQL (Geographic Object Query Language) for filtering features:

Feature Types

• n - Nodes (points)
• w - Ways (lines, excluding areas)
• a - Areas (polygons)
• r - Relations (excluding areas)
• * - Any type

Types can be combined: na selects nodes and areas.

Tag Filters

na[amenity=restaurant]              # Exact match
w[highway]                          # Tag exists
w[highway][!oneway]                 # Tag doesn't exist or is not 'yes'
na[amenity=bar,pub,cafe]           # Multiple values
w[highway=residential][name]        # Multiple conditions
na[name=The*]                       # Wildcard match
na[population>=1000000]             # Numeric comparison

Examples

na[amenity=restaurant]                      # Restaurants
w[highway]                                  # All roads
na[tourism=hotel][stars>=4]                # 4+ star hotels
w[highway=residential][!oneway]            # Non-oneway residential streets
na[amenity=restaurant,cafe,bar]           # Food & drink establishments
a[leisure=park][name]                      # Named parks
n[highway=traffic_signals]                 # Traffic lights

API Reference

GeoDesk

Main interface to GOL files.

• open(path) - Open a GOL file
• query(goql, bbox) - Execute a GOQL query
• query_amenities(type, bbox) - Query amenities by type
• query_restaurants(bbox) - Query restaurants
• query_cafes(bbox) - Query cafes
• query_bars(bbox) - Query bars and pubs
• query_bus_stops(bbox) - Query bus stops
• query_roads(bbox) - Query roads
• query_all_amenities(bbox) - Query all amenities

BoundingBox

Represents a geographic bounding box.

• new(west, south, east, north) - Create from coordinates
• from_center(lon, lat, radius) - Create from center and radius

QueryResult

Result of a query operation.

• count() - Number of features
• is_empty() - Check if empty
• to_vec() - Convert to vector of features

Feature

Represents an OSM feature.

• id - OSM ID
• type_name - Feature type ("node", "way", "relation")
• name - Name tag value
• lon, lat - Coordinates
• tags - All tags as key-value pairs
• tag(key) - Get tag value
• has_tag(key) - Check if tag exists

Building from Source

# Clone the repository
git clone https://github.com/yourusername/geodesk-rs
cd geodesk-rs

# Build (GeoDESK will be automatically fetched and built via CMake)
cargo build --release

# Run examples
cargo run --example query_restaurants
cargo run --example query_roads_copenhagen
cargo run --example custom_queries

Note: The first build will take several minutes as CMake downloads and compiles the GeoDESK C++ library automatically using FetchContent. Subsequent builds will be much faster as the library is cached.

Examples

The examples/ directory contains several examples:

• query_restaurants.rs - Query restaurants in Montreal
• query_roads_copenhagen.rs - Query roads and bus stops in Copenhagen
• custom_queries.rs - Various GOQL query examples

Run them with:

cargo run --example query_restaurants

Performance

GeoDESK is designed for high-performance queries:

• Queries are executed lazily
• Spatial indexing for fast bounding box lookups
• Zero-copy access to GOL data
• Efficient tag filtering

Troubleshooting

"geodesk.h not found"

Make sure GeoDESK is installed and either:

• Set GEODESK_PATH environment variable
• Install GeoDESK headers to /usr/local/include

"cannot find -lgeodesk"

Ensure the GeoDESK library is in your library path:

export LD_LIBRARY_PATH=$GEODESK_PATH/lib:$LD_LIBRARY_PATH  # Linux
export DYLD_LIBRARY_PATH=$GEODESK_PATH/lib:$DYLD_LIBRARY_PATH  # macOS

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the same terms as the GeoDESK library.

Resources

• GeoDESK Website
• GeoDESK Documentation
• GeoDESK C++ API
• GOQL Reference
• OpenStreetMap
• cxx.rs Documentation

Acknowledgments

• GeoDESK C++ library by Clarisma
• OpenStreetMap contributors
• cxx.rs by David Tolnay