Expand description
OGC Well-Known Binary (WKB) reader and writer.
Follows OGC Simple Feature Access 06-103r4 §8 (Boost.Geometry ships
no WKB). The parser emits a geometry_model::DynGeometry; the
writer serialises concrete model geometries with to_wkb and any
user-defined polygon implementing the geometry traits with
to_wkb_polygon.
§Serialize a user-defined polygon
Application types can implement the lightweight geometry_trait traits
directly; they do not need to be converted to a geometry_model polygon.
use geometry_cs::Cartesian;
use geometry_io_wkb::{from_wkb, to_wkb_polygon, ByteOrder};
use geometry_tag::{PointTag, PolygonTag, RingTag};
use geometry_trait::{Geometry, Point, Polygon, Ring};
struct Coordinate(f64, f64);
impl Geometry for Coordinate {
type Kind = PointTag;
type Point = Self;
}
impl Point for Coordinate {
type Scalar = f64;
type Cs = Cartesian;
const DIM: usize = 2;
fn get<const D: usize>(&self) -> f64 {
match D {
0 => self.0,
1 => self.1,
_ => unreachable!("a Coordinate has two dimensions"),
}
}
}
struct Boundary(Vec<Coordinate>);
impl Geometry for Boundary {
type Kind = RingTag;
type Point = Coordinate;
}
impl Ring for Boundary {
fn points(&self) -> impl ExactSizeIterator<Item = &Coordinate> + Clone {
self.0.iter()
}
}
struct Parcel {
exterior: Boundary,
holes: Vec<Boundary>,
}
impl Geometry for Parcel {
type Kind = PolygonTag;
type Point = Coordinate;
}
impl Polygon for Parcel {
type Ring = Boundary;
fn exterior(&self) -> &Boundary {
&self.exterior
}
fn interiors(&self) -> impl ExactSizeIterator<Item = &Boundary> {
self.holes.iter()
}
}
let parcel = Parcel {
exterior: Boundary(vec![
Coordinate(0.0, 0.0),
Coordinate(0.0, 2.0),
Coordinate(2.0, 2.0),
Coordinate(2.0, 0.0),
Coordinate(0.0, 0.0),
]),
holes: vec![],
};
let bytes = to_wkb_polygon(&parcel, ByteOrder::LittleEndian);
assert_eq!(bytes[0], 0x01);
assert!(from_wkb(&bytes).is_ok());Enums§
- Byte
Order - The two byte orders a WKB record may declare.
- WkbError
- Everything that can go wrong reading WKB.
Functions§
- from_
wkb - Parse an OGC Well-Known Binary buffer into a runtime-tagged
DynGeometry. - to_wkb
- Serialise a geometry to an OGC Well-Known Binary byte vector in the
caller-chosen
ByteOrder. - to_
wkb_ polygon - Serialise any polygon implementing
PolygonTraitto OGC WKB.