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use crate::{GeoNum, MultiPolygon, Polygon};
use crate::algorithm::winding_order::{Winding, WindingOrder};
pub trait Orient {
fn orient(&self, orientation: Direction) -> Self;
}
impl<T> Orient for Polygon<T>
where
T: GeoNum,
{
fn orient(&self, direction: Direction) -> Polygon<T> {
orient(self, direction)
}
}
impl<T> Orient for MultiPolygon<T>
where
T: GeoNum,
{
fn orient(&self, direction: Direction) -> MultiPolygon<T> {
MultiPolygon(self.iter().map(|poly| poly.orient(direction)).collect())
}
}
#[derive(Copy, Clone, Debug)]
pub enum Direction {
Default,
Reversed,
}
fn orient<T>(poly: &Polygon<T>, direction: Direction) -> Polygon<T>
where
T: GeoNum,
{
let interiors = poly
.interiors()
.iter()
.map(|l| {
l.clone_to_winding_order(match direction {
Direction::Default => WindingOrder::Clockwise,
Direction::Reversed => WindingOrder::CounterClockwise,
})
})
.collect();
let ext_ring = poly.exterior().clone_to_winding_order(match direction {
Direction::Default => WindingOrder::CounterClockwise,
Direction::Reversed => WindingOrder::Clockwise,
});
Polygon::new(ext_ring, interiors)
}
#[cfg(test)]
mod test {
use super::*;
use crate::{LineString, Polygon};
#[test]
fn test_polygon_orientation() {
let points_ext = vec![(1.0, 0.0), (0.0, 1.0), (1.0, 2.0), (2.0, 1.0), (1.0, 0.0)];
let points_int = vec![(1.0, 0.5), (1.5, 1.0), (1.0, 1.5), (0.5, 1.0), (1.0, 0.5)];
let poly1 = Polygon::new(
LineString::from(points_ext),
vec![LineString::from(points_int)],
);
let oriented_ext = vec![(1.0, 0.0), (2.0, 1.0), (1.0, 2.0), (0.0, 1.0), (1.0, 0.0)];
let oriented_ext_ls = LineString::from(oriented_ext);
let oriented_int_raw = vec![(1.0, 0.5), (0.5, 1.0), (1.0, 1.5), (1.5, 1.0), (1.0, 0.5)];
let oriented_int_ls = LineString::from(oriented_int_raw);
let oriented = orient(&poly1, Direction::Default);
assert_eq!(oriented.exterior().0, oriented_ext_ls.0);
assert_eq!(oriented.interiors()[0].0, oriented_int_ls.0);
}
}