geometry-rtree

Part of the boost_geometry workspace — a Rust port of Boost.Geometry. Most users should depend on the facade crate, which re-exports this one; depend on this crate directly only for a slimmer build.

An R-tree spatial index over the geometry kernel.

Mirrors boost/geometry/index/rtree.hpp and the support headers under boost/geometry/index/detail/. Stores any Indexable value (a value with an axis-aligned bounding box) and answers spatial queries — intersects / within / contains — and k-nearest-neighbour search, pruning the tree with each node's bounding box.

The split strategy is a type parameter of [Rtree]. The default is [AsymmetricRStarSplit] with six-child branches and 12-value leaves for insertion, and four-child branches/four-value leaves for bulk packing; symmetric [RStarSplit], [Quadratic], and [Linear] configurations remain available. Bulk loading via [FromIterator] uses Sort-Tile-Recursive packing for a balanced tree in one pass. See [split] for parameter semantics, validity constraints, tuning guidance, and the benchmark evidence behind the default.

Cartesian, 2D, f64 for v1.

Index polygons and query a point

Implement Indexable for an application type by returning its axis-aligned bounds, then build an [Rtree] from an iterator. This example uses rectangular polygons, so a bounds intersection with a point is also an exact polygon intersection. For other polygon shapes, treat the result as a candidate set and apply an exact point-in-polygon test afterward.

use geometry_rtree::{Bounds, Indexable, Predicate, Rtree};

#[derive(Debug)]
struct Parcel {
    name: &'static str,
    boundary: [[f64; 2]; 5],
    bounds: Bounds,
}

impl Parcel {
    fn rectangle(name: &'static str, min: [f64; 2], max: [f64; 2]) -> Self {
        Self {
            name,
            boundary: [
                min,
                [min[0], max[1]],
                max,
                [max[0], min[1]],
                min,
            ],
            bounds: Bounds::new(min, max),
        }
    }
}

impl Indexable for Parcel {
    fn bounds(&self) -> Bounds {
        self.bounds
    }
}

let parcels = [
    Parcel::rectangle("park", [0.0, 0.0], [4.0, 3.0]),
    Parcel::rectangle("school", [5.0, 0.0], [8.0, 2.0]),
    Parcel::rectangle("lake", [1.0, 5.0], [3.0, 7.0]),
];
let tree: Rtree<Parcel> = parcels.into_iter().collect();

let point = Bounds::point([2.0, 1.0]);
let hits = tree.query(Predicate::Intersects(point));

assert_eq!(hits.len(), 1);
assert_eq!(hits[0].name, "park");
assert_eq!(hits[0].boundary[0], [0.0, 0.0]);

Module layout:

• [bounds] — the axis-aligned box arithmetic (area, enlargement, union, distance) the tree keys on.
• indexable — the Indexable trait.
• [node] — the leaf / branch Node enum.
• [split] — the [SplitParameters] strategies.
• [predicate] — the query [Predicate]s.
• rtree — the [Rtree] and its insert / query / nearest / bulk load.
• [query_iter] — [QueryIter], the lazy spatial-query walk.
• [nearest_iter] — [NearestIter], the unbounded nearest-first stream.
• search_frontier / nearest_bound (crate-internal) — the nearest search's stack-first frontier and k-th-best rank buffer.

License

BSL-1.0 — see LICENSE.