Struct libreda_db::prelude::SimpleRPolygon

pub struct SimpleRPolygon<T> where
    T: CoordinateType,  { /* fields omitted */ }

A SimpleRPolygon is a rectilinear polygon. It does not contain holes but can be self-intersecting. The vertices are stored in an implicit format (one coordinate of two neighbour vertices is always the same for rectilinear polygons). This reduces memory usage but has the drawback that edges must alternate between horizontal and vertical. Vertices between two edges of the same orientation will be dropped.

Implementations

impl<T> SimpleRPolygon<T> where
    T: CoordinateType, 

pub fn try_new<P>(points: Vec<P, Global>) -> Option<SimpleRPolygon<T>> where
    P: Copy + Into<Point<T>>, 

Create new rectilinear polygon from points. Returns None if the polygon defined by the points is not rectilinear.

use iron_shapes::simple_rpolygon::SimpleRPolygon;

let poly1 = SimpleRPolygon::try_new(vec![(0, 0), (1, 0), (1, 1), (0, 1)]);
assert!(poly1.is_some());

// A triangle cannot be rectilinear.
let poly1 = SimpleRPolygon::try_new(vec![(0, 0), (1, 0), (1, 1)]);
assert!(poly1.is_none());

pub fn empty() -> SimpleRPolygon<T>

Create empty polygon without any vertices.

pub fn num_points(&self) -> usize

Get the number of vertices.

pub fn points(&self) -> impl Iterator<Item = Point<T>>

Iterate over the points.

pub fn convex_hull(&self) -> SimplePolygon<T> where
    T: Ord, 

Get the convex hull of the polygon.

Implements Andrew's Monotone Chain algorithm. See: http://geomalgorithms.com/a10-_hull-1.html

pub fn edges(&self) -> impl Iterator<Item = REdge<T>>

Get all exterior edges of the polygon.

Examples

use iron_shapes::simple_rpolygon::SimpleRPolygon;
use iron_shapes::redge::REdge;
let coords = vec![(0, 0), (1, 0), (1, 1), (0, 1)];

let poly = SimpleRPolygon::try_new(coords).unwrap();
let edges: Vec<_> = poly.edges().collect();
assert_eq!(edges, vec![
    REdge::new((0, 0), (1, 0)),
    REdge::new((1, 0), (1, 1)),
    REdge::new((1, 1), (0, 1)),
    REdge::new((0, 1), (0, 0)),
]);

pub fn lower_left_vertex(&self) -> Point<T>

Get the vertex with lowest x-coordinate. Prefer lower y-coordinates to break ties.

Examples

use iron_shapes::simple_rpolygon::SimpleRPolygon;
use iron_shapes::point::Point;
let coords = vec![(0, 0), (1, 0), (1, 1), (0, 1)];

let poly = SimpleRPolygon::try_new(coords).unwrap();

assert_eq!(poly.lower_left_vertex(), Point::new(0, 0));

pub fn orientation(&self) -> Orientation

Get the orientation of the polygon, i.e. check if it is wound clock-wise or counter-clock-wise.

Examples

use iron_shapes::simple_rpolygon::SimpleRPolygon;
use iron_shapes::point::Point;
use iron_shapes::types::Orientation;
let coords = vec![(0, 0), (1, 0), (1, 1), (0, 1)];

let poly = SimpleRPolygon::try_new(coords).unwrap();

assert_eq!(poly.orientation(), Orientation::CounterClockWise);

Trait Implementations

impl<T> Clone for SimpleRPolygon<T> where
    T: Clone + CoordinateType, 

pub fn clone(&self) -> SimpleRPolygon<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Debug for SimpleRPolygon<T> where
    T: Debug + CoordinateType, 

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

Formats the value using the given formatter.

impl<T> DoubledOrientedArea<T> for SimpleRPolygon<T> where
    T: CoordinateType, 

pub fn area_doubled_oriented(&self) -> T

Calculates the doubled oriented area.

Using doubled area allows to compute in the integers because the area of a polygon with integer coordinates is either integer or half-integer.

The area will be positive if the vertices are listed counter-clockwise, negative otherwise.

Complexity: O(n)

Examples

use iron_shapes::traits::DoubledOrientedArea;
use iron_shapes::simple_rpolygon::SimpleRPolygon;
let coords = vec![(0, 0), (1, 0), (1, 1), (0, 1)];

let poly = SimpleRPolygon::try_new(coords).unwrap();

assert_eq!(poly.area_doubled_oriented(), 2);

impl<T> Eq for SimpleRPolygon<T> where
    T: Eq + CoordinateType, 

impl<T> From<Rect<T>> for SimpleRPolygon<T> where
    T: CoordinateType, 

pub fn from(r: Rect<T>) -> SimpleRPolygon<T>

Performs the conversion.

impl<T> Hash for SimpleRPolygon<T> where
    T: Hash + CoordinateType, 

pub fn hash<__H>(&self, state: &mut __H) where
    __H: Hasher, 

Feeds this value into the given Hasher.

pub fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<T> PartialEq<SimpleRPolygon<T>> for SimpleRPolygon<T> where
    T: CoordinateType, 

pub fn eq(&self, rhs: &SimpleRPolygon<T>) -> bool

Equality test for simple polygons.

Two polygons are equal iff a cyclic shift on their vertices can be applied such that the both lists of vertices match exactly.

Complexity: O(n^2)

TODO: Normalized ordering of vertices for faster comparison.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<T> StructuralEq for SimpleRPolygon<T> where
    T: CoordinateType, 

impl<T> TryBoundingBox<T> for SimpleRPolygon<T> where
    T: CoordinateType, 

pub fn try_bounding_box(&self) -> Option<Rect<T>>

Return the bounding box of this geometry if a bounding box is defined.

impl<T, Dst> TryCastCoord<T, Dst> for SimpleRPolygon<T> where
    T: CoordinateType + NumCast,
    Dst: CoordinateType + NumCast, 

type Output = SimpleRPolygon<Dst>

Output type of the cast. This is likely the same geometrical type just with other coordinate types.

pub fn try_cast(
    &self
) -> Option<<SimpleRPolygon<T> as TryCastCoord<T, Dst>>::Output>

Try to cast to target data type.

pub fn cast(&self) -> Self::Output

Cast to target data type.

impl<T> WindingNumber<T> for SimpleRPolygon<T> where
    T: CoordinateType, 

pub fn winding_number(&self, point: Point<T>) -> isize

Calculate the winding number of the polygon around this point.

TODO: Define how point on edges and vertices is handled.

See: http://geomalgorithms.com/a03-_inclusion.html

pub fn contains_point_non_oriented(&self, point: Point<T>) -> bool

Check if point is inside the polygon, i.e. the polygons winds around the point a non-zero number of times.

pub fn contains_point(&self, point: Point<T>) -> bool

Check if point is inside the polygon, i.e. the polygon winds around the point an odd number of times.