Struct Geofence 

pub struct Geofence { /* private fields */ }

Keeping a tracked point inside an area, and noticing when it leaves.

This is the primitive behind “tell me when it leaves the safe zone”: a collared animal straying from its pasture, an asset moving off-site, or a drone crossing its allowed boundary. A fence is a centre and a radius; feeding it successive fixes reports whether each is Inside or Outside and, crucially, the single fix that Exited or Entered, so an alert fires once on the crossing rather than on every fix while away.

Examples

use pamoja_kit::{Boundary, Coordinate, Geofence};

// A 50 m pen around the waterpoint; the collar fix then wanders out.
let mut pen = Geofence::new(Coordinate::new(-1.2921, 36.8219), 50.0);
assert_eq!(pen.update(Coordinate::new(-1.2921, 36.8219)), Boundary::Inside);
assert_eq!(pen.update(Coordinate::new(-1.2930, 36.8219)), Boundary::Exited);

Implementations

impl Geofence

pub fn new(center: Coordinate, radius_m: f64) -> Self

Creates a fence of radius_m metres around center.

Arguments

• center - the middle of the safe area.
• radius_m - the radius of the safe area in metres; its magnitude is used.

Returns

A fence that has not yet seen a fix.

pub fn contains(&self, point: Coordinate) -> bool

Returns whether a point lies within the fence.

Arguments

• point - the coordinate to test.

Returns

true if point is on or inside the fence boundary.

pub fn update(&mut self, point: Coordinate) -> Boundary

Records a fix and reports its position relative to the fence.

Arguments

• point - the latest fix.

Returns

Boundary::Entered or Boundary::Exited on the fix that crosses the boundary, otherwise Boundary::Inside or Boundary::Outside.

Trait Implementations

impl Clone for Geofence

fn clone(&self) -> Geofence

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Geofence

impl Debug for Geofence

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Geofence

fn eq(&self, other: &Geofence) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Geofence