Struct GenericPolygon

Source

pub struct GenericPolygon<PointType> { /* private fields */ }

Expand description

Generic struct to create Polygon; PolygonM, PolygonZ

Polygons can have multiple parts (or rings)

To create a polygon with only one part use new.

To create a polygon with multiple rings use with_rings.

§Notes

A Polygon ring is a connected sequence of 4 or more points (this is not checked)
Polygon’s rings MUST be closed (the first and last points MUST be the same) (p 13/34) (this is done by the constructors if you do not do it yourself)
The order of rings is not significant (p 13/34)
A polygon may have multiple Outer rings (p12/34)

§geo-types

shapefile’s Polygons can be converted to geo-types’s MultiPolygon<f64>, but not geo-types’s Polygon as they only allow polygons with one outer ring.

geo-types’s Polygon<f64> and MultiPolygon<f64> can be converted to shapefile’s Polygon

let mut polygons = shapefile::read_shapes_as::<_, shapefile::PolygonM>("tests/data/polygonm.shp")?;
let geo_polygon: geo_types::MultiPolygon<f64> = polygons.pop().unwrap().into();
let polygon = shapefile::PolygonZ::from(geo_polygon);

Implementations§

Source §

impl<PointType> GenericPolygon<PointType>
where PointType: ShrinkablePoint + GrowablePoint + PartialEq + HasXY + Copy,

Source

pub fn new(ring: PolygonRing<PointType>) -> Self

Creates a polygon with only one ring

The ring will be closed if it is not (shapefiles requires the first and last point to be equal)

The ring points may be reordered to match their type (see PolygonRing)

§Examples

use shapefile::{PolygonRing, PointZ, PolygonZ, NO_DATA};
let ring = PolygonRing::Outer(vec![
    PointZ::new(0.0, 0.0, 0.0, NO_DATA),
    PointZ::new(0.0, 1.0, 0.0, NO_DATA),
    PointZ::new(1.0, 1.0, 0.0, NO_DATA),
    PointZ::new(1.0, 0.0, 0.0, NO_DATA),
]);
let poly = PolygonZ::new(ring);
assert_eq!(poly.rings()[0].points().first(), poly.rings()[0].points().last());

Source §

impl<PointType> GenericPolygon<PointType>
where PointType: GrowablePoint + ShrinkablePoint + PartialEq + HasXY + Copy,

Source

pub fn with_rings(rings: Vec<PolygonRing<PointType>>) -> Self

Creates a polygon with multiple rings

The ring will be closed if it is not (shapefiles requires the first and last point to be equal)

The ring points may be reordered to match their type (see PolygonRing)

§Example

use shapefile::{PolygonRing, Point, Polygon};
let polygon = Polygon::with_rings(vec![
    PolygonRing::Outer(vec![
        Point::new(-120.0, 60.0),
        Point::new(-120.0, -60.0),
        Point::new(120.0, -60.0),
        Point::new(120.0, 60.0),
        Point::new(-120.0, 60.0),
    ]),
    PolygonRing::Inner(vec![
         Point::new(-60.0, 30.0),
         Point::new(60.0, 30.0),
         Point::new(60.0, -30.0),
         Point::new(-60.0, -30.0),
         Point::new(-60.0, 30.0),
    ]),
]);

assert_eq!(polygon.rings().len(), 2);

Source §

impl<PointType> GenericPolygon<PointType>

Source

pub fn bbox(&self) -> &GenericBBox<PointType>

Returns the bounding box associated to the polygon

Source

pub fn rings(&self) -> &[PolygonRing<PointType>]

Returns the rings of the polygon

Source

pub fn ring(&self, index: usize) -> Option<&PolygonRing<PointType>>

Returns the ring as index

§Example

use shapefile::{polygon, NO_DATA};

let polygon = polygon!{
    Outer(
        (0.0, 0.0, 0.0, NO_DATA),
        (0.0, 1.0, 0.0, NO_DATA),
        (1.0, 1.0, 0.0, NO_DATA),
        (1.0, 0.0, 0.0, NO_DATA),
    )
};

assert_eq!( polygon.ring(0).is_some(), true);
assert_eq!(polygon.ring(1), None);