# Supercluster
A very fast Rust crate for geospatial point clustering.
This crate is inspired by Mapbox's supercluster [blog post](https://blog.mapbox.com/clustering-millions-of-points-on-a-map-with-supercluster-272046ec5c97).
## Reference implementation
[](https://github.com/chargetrip/supercluster-rs/actions/workflows/test.yml)
[](https://docs.rs/supercluster)
[](https://crates.io/crates/supercluster)
[](https://codecov.io/gh/chargetrip/supercluster-rs)
## Features
- `load(points)`: Loads a [FeatureCollection](https://datatracker.ietf.org/doc/html/rfc7946#section-3.3) Object. Each feature should be a [Feature Object](https://datatracker.ietf.org/doc/html/rfc7946#section-3.2).
- `get_clusters(bbox, zoom)`: For the given `bbox` array (`[west_lng, south_lat, east_lng, north_lat]`) and `zoom`, returns an array of clusters and points as [Feature Object](https://datatracker.ietf.org/doc/html/rfc7946#section-3.2) objects.
- `get_tile(z, x, y)`: For a given zoom and x/y coordinates, returns a [FeatureCollection](https://datatracker.ietf.org/doc/html/rfc7946#section-3.3) Object.
- `get_children(cluster_id)`: Returns the children of a cluster (on the next zoom level) given its id (`cluster_id` value from feature properties).
- `get_leaves(cluster_id, limit, offset)`: Returns all the points of a cluster (given its `cluster_id`), with pagination support.
- `get_cluster_expansion_zoom(cluster_id)`: Returns the zoom on which the cluster expands into several children (useful for "click to zoom" feature) given the cluster's `cluster_id`.
## Options
| `min_zoom` | Minimum zoom level at which clusters are generated. |
| `max_zoom` | Maximum zoom level at which clusters are generated. |
| `min_points` | Minimum number of points to form a cluster. |
| `radius` | Cluster radius, in pixels. |
| `extent` | (Tiles) Tile extent. Radius is calculated relative to this value. |
| `node_size` | Size of the KD-tree leaf node. Affects performance. |
## Safety
This crate uses `#![forbid(unsafe_code)]` to ensure everything is implemented in 100% safe Rust.
## Documentation
For more in-depth details, please refer to the full [documentation](https://docs.rs/supercluster).
If you encounter any issues or have questions that are not addressed in the documentation, feel free to [submit an issue](https://github.com/chargetrip/supercluster-rs/issues).
## Usage
Run the following Cargo command in your project directory:
```bash
cargo add supercluster
```
```rust
use geojson::FeatureCollection;
use supercluster::{ Supercluster, Options };
fn main() {
let options = Options {
max_zoom: 16,
min_zoom: 0,
min_points: 2,
radius: 40.0,
node_size: 64,
extent: 512.0,
};
// Create a new instance with the specified configuration settings
let mut cluster = Supercluster::new(options);
// Load a FeatureCollection Object into the Supercluster instance
// [GeoJSON Format Specification § 5](https://tools.ietf.org/html/rfc7946#section-5)
let feature_collection = FeatureCollection {
bbox: None,
// [GeoJSON Format Specification § 3.2](https://datatracker.ietf.org/doc/html/rfc7946#section-3.2)
features: vec![],
foreign_members: None,
};
let index = cluster.load(feature_collection);
// Retrieve a FeatureCollection Object within a tile at the given zoom level and tile coordinates
let tile = index.get_tile(0, 0.0, 0.0).expect("cannot get a tile");
...
}
```
## Contributing
Build:
```bash
cargo build
```
Test:
```bash
cargo test
```
Run [clippy](https://github.com/rust-lang/rust-clippy):
```bash
cargo clippy --all-targets --all-features --no-deps -- -D warnings
```
Run [rustfmt](https://github.com/rust-lang/rustfmt):
```bash
cargo fmt
```
Generate documentation in HTML format:
```bash
cargo doc --open
```
## Sponsors
[](https://www.chargetrip.com)