Struct triangulation::dcel::TrianglesDCEL

pub struct TrianglesDCEL {
    pub vertices: Vec<usize>,
    pub halfedges: Vec<OptionIndex>,
    // some fields omitted
}

Doubly connected edge list (a.k.a. half-edge data structure) of triangles

Fields

vertices: Vec<usize>

Maps edge id to start point id

halfedges: Vec<OptionIndex>

Maps edge id to the opposite edge id in the adjacent triangle, if it exists

Methods

impl TrianglesDCEL

pub fn with_capacity(cap: usize) -> TrianglesDCEL

Constructs a new DCEL with specified capacity.

The DCEL will be able to hold at most cap triangles.

pub fn num_triangles(&self) -> usize

Returns the number of triangles in the triangulation

pub fn triangles<'a, 'b: 'a>(
    &'a self,
    points: &'b [Point]
) -> impl Iterator<Item = Triangle> + 'a

Returns the iterator over all triangles in the triangulation

pub fn add_triangle(&mut self, points: [usize; 3]) -> usize

Adds a new triangle from given point ids to the DCEL and returns its id. Triangles id + 1 and id + 2 will reference to the same triangle viewed from different points.

Make sure points is ordered in counter-clockwise order.

pub fn triangle_points(&self, t: usize) -> [usize; 3]

Returns point ids of the given triangle.

Examples

let mut dcel = TrianglesDCEL::with_capacity(3);
let t = dcel.add_triangle([0, 1, 2]);
assert_eq!(dcel.triangle_points(t), [0, 1, 2]);
assert_eq!(dcel.triangle_points(t + 1), [1, 2, 0]);
assert_eq!(dcel.triangle_points(t + 2), [2, 0, 1]);

pub fn triangle(&self, t: usize, points: &[Point]) -> Triangle

Returns the actual triangle associated with the given id.

Examples

let points = &[Point::new(10.0, 10.0), Point::new(10.0, 100.0), Point::new(100.0, 10.0)];

let mut dcel = TrianglesDCEL::with_capacity(3);
let t = dcel.add_triangle([0, 1, 2]);
assert_eq!(dcel.triangle(t, points), Triangle(points[0], points[1], points[2]));

pub fn triangle_first_edge(&self, t: usize) -> usize

Returns id of the first triangle edge (e.g. the value returned from add_triangle).

Examples

let mut dcel = TrianglesDCEL::with_capacity(3);
let t = dcel.add_triangle([0, 1, 2]);
assert_eq!(dcel.triangle_first_edge(t), t);
assert_eq!(dcel.triangle_first_edge(t + 1), t);
assert_eq!(dcel.triangle_first_edge(t + 2), t);

pub fn next_edge(&self, edge: usize) -> usize

Returns the edge next to the specified one (counter-clockwise order).

Examples

let mut dcel = TrianglesDCEL::with_capacity(3);
assert_eq!(dcel.next_edge(0), 1);
assert_eq!(dcel.next_edge(1), 2);
assert_eq!(dcel.next_edge(2), 0);

pub fn prev_edge(&self, edge: usize) -> usize

Returns the edge next previous for the specified one (counter-clockwise order).

Examples

let mut dcel = TrianglesDCEL::with_capacity(3);
assert_eq!(dcel.prev_edge(0), 2);
assert_eq!(dcel.prev_edge(1), 0);
assert_eq!(dcel.prev_edge(2), 1);

pub fn twin(&self, edge: usize) -> Option<usize>

Returns the twin edge id, if it exists.

pub fn link(&mut self, a: usize, b: usize)

Mark two given edges as twins.

Examples

let mut dcel = TrianglesDCEL::with_capacity(6);
let a = dcel.add_triangle([0, 1, 2]);
let b = dcel.add_triangle([2, 1, 3]);
dcel.link(a + 1, b);
assert_eq!(dcel.twin(a + 1), Some(b));
assert_eq!(dcel.twin(b), Some(a + 1));

pub fn unlink(&mut self, a: usize)

Removes twin of the given edge.

pub fn link_option(&mut self, a: usize, b: Option<usize>)

If b is Some works like link, otherwise removes the twin of a.

Important traits for TrianglesAroundPoint<'a>

impl<'a> Iterator for TrianglesAroundPoint<'a> type Item = usize;

pub fn triangles_around_point<'a>(
    &'a self,
    p: usize
) -> TrianglesAroundPoint<'a>

Returns the iterator of triangles around the given point.

init_revmap must be called beforehand to initialize the point-to-triangle map.

pub fn init_revmap(&mut self)

Initializes the point-to-triangle map.

Trait Implementations

impl Clone for TrianglesDCEL

fn clone(&self) -> TrianglesDCEL

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for TrianglesDCEL

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

Formats the value using the given formatter.