Crate cdt

cdt is a library for calculating Delaunay and constrained Delaunay triangulations.

It is optimized for correctness and speed, using exact predicates to perform point-in-circle and orientation tests.

Examples

Delaunay triangulation

This triangulates a set of four points in a square

let pts = vec![(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 1.0)];
let triangles = cdt::triangulate_points(&pts).unwrap();
assert!(triangles.len() == 2);
for t in triangles {
    println!("{:?} {:?} {:?}", pts[t.0], pts[t.1], pts[t.2])
}

Constrained Delaunay triangulation

This triangulates an inner and outer square

let pts = vec![(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 1.0),
               (0.2, 0.2), (0.8, 0.2), (0.8, 0.8), (0.2, 0.8)];
let triangles = cdt::triangulate_contours(&pts,
        &[vec![0, 1, 2, 3, 0], vec![4, 5, 6, 7, 4]])
    .unwrap();
for t in triangles {
    println!("{:?} {:?} {:?}", pts[t.0], pts[t.1], pts[t.2])
}

Crate features

By default, the library uses u32 indexes for internal data structures, to improve performance. If you are planning to triangulate more than 500M points in a single pass, you should enable the long-indexes feature.

Structs

Triangulation

This struct contains all of the data needed to generate a (constrained) Delaunay triangulation of a set of input points and edges. It is a low-level API; consider using the module-level functions if you don’t need total control.

Enums

Error

Single error type for this library

Functions

save_debug_panic

Given a set of points and edges which are known to panic, figures out the max number of save steps, then saves an SVG right before the panic occurs

triangulate_contours

Triangulates a set of contours, given as indexed paths into the point list. Each contour must be closed (i.e. the last point in the contour must equal the first point), otherwise Error::OpenContour will be returned.

triangulate_points

Triangulates a set of points, returning triangles as triples of indexes into the original points list. The resulting triangulation has a convex hull.

triangulate_with_edges

Triangulates a set of points with certain fixed edges. The edges are assumed to form closed boundaries; only triangles within those boundaries will be returned.