Trait rstar::RTreeObject

source · [−]

pub trait RTreeObject {
    type Envelope: Envelope;
    fn envelope(&self) -> Self::Envelope;
}

Expand description

An object that can be inserted into an r-tree.

This trait must be implemented for any object to be inserted into an r-tree. Some simple objects that already implement this trait can be found in the crate::primitives module.

The only property required of such an object is its crate::Envelope. Most simply, this method should return the axis aligned bounding box of the object. Other envelope types may be supported in the future.

Note: It is a logic error if an object’s envelope changes after insertion into an r-tree.

Type parameters

Envelope: The object’s envelope type. At the moment, only AABB is available.

Example implementation

use rstar::{RTreeObject, AABB};

struct Player
{
    name: String,
    x_coordinate: f64,
    y_coordinate: f64
}

impl RTreeObject for Player
{
    type Envelope = AABB<[f64; 2]>;

    fn envelope(&self) -> Self::Envelope
    {
        AABB::from_point([self.x_coordinate, self.y_coordinate])
    }
}

use rstar::RTree;

let mut tree = RTree::new();

// Insert a few players...
tree.insert(Player {
    name: "Forlorn Freeman".into(),
    x_coordinate: 1.,
    y_coordinate: 0.
});
tree.insert(Player {
    name: "Sarah Croft".into(),
    x_coordinate: 0.5,
    y_coordinate: 0.5,
});
tree.insert(Player {
    name: "Geralt of Trivia".into(),
    x_coordinate: 0.,
    y_coordinate: 2.,
});

// Now we are ready to ask some questions!
let envelope = AABB::from_point([0.5, 0.5]);
let likely_sarah_croft = tree.locate_in_envelope(&envelope).next();
println!("Found {:?} lurking around at (0.5, 0.5)!", likely_sarah_croft.unwrap().name);

let unit_square = AABB::from_corners([-1.0, -1.0], [1., 1.]);
for player in tree.locate_in_envelope(&unit_square) {
   println!("And here is {:?} spelunking in the unit square.", player.name);
}