Enum TriangulationError 

#[non_exhaustive]
pub enum TriangulationError {
    TooFewPoints,
    AllPointsCollinear,
    VertexUnplaceable {
        index: u32,
    },
    ConstraintOutOfRange {
        index: u32,
    },
    CrossingConstraints {
        a: u32,
        b: u32,
    },
    CoincidentConstraint {
        a: u32,
        b: u32,
    },
    RingOutOfRange {
        ring: u32,
        index: u32,
    },
    TooFewRingVertices {
        ring: u32,
    },
    RepeatedRingVertex {
        ring: u32,
        index: u32,
    },
    FoldedRing {
        ring: u32,
        index: u32,
    },
    MisnestedRing {
        ring: u32,
        winding: i32,
    },
    EmptyDomain,
    NonFinitePoint {
        index: u32,
    },
}

Why a triangulation could not be produced.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

TooFewPoints

Fewer than three points were supplied, so no triangle exists.

AllPointsCollinear

Every input point is collinear, so the triangulation has zero area.

Reported rather than returning an empty triangulation: a caller that asked to triangulate a degenerate polygon has a bug upstream, and an empty result would hide it.

VertexUnplaceable

A vertex could not be placed in any triangle during insertion.

Indicates a corrupted adjacency rather than bad input. Reported so a missing vertex surfaces as an error instead of as a silent hole in an otherwise valid-looking mesh.

Fields

index: u32

Index of the vertex that could not be placed.

ConstraintOutOfRange

A constraint referenced a vertex index that does not exist.

Fields

index: u32

The offending index.

CrossingConstraints

Two constraint pieces cross; a constraint is split at the vertices on it first.

Only reachable when two constraints cross at a point that is no input vertex: an edge cannot survive if another required edge passes through it. The crossing point would have to be inserted as a vertex, which changes the caller’s input, so this is reported instead of silently repaired. A constraint that runs through input vertices, or ends on another constraint, is not a crossing.

Fields

a: u32

First endpoint of the piece that could not be recovered.

b: u32

Second endpoint.

CoincidentConstraint

A constraint joins two input points at exactly the same position.

Coincident points are merged into one vertex, so the constraint would be an edge from that vertex to itself. Reported rather than dropped: a caller who asked for an edge between two distinct indices has two points where they meant one, or one where they meant two.

Fields

a: u32

First endpoint, as an input index.

b: u32

Second endpoint, as an input index.

RingOutOfRange

A ring referenced a vertex index that does not exist.

Fields

ring: u32

Position of the ring in the ring list.

index: u32

The offending index.

TooFewRingVertices

A ring has fewer than three vertices, so it encloses nothing.

Fields

ring: u32

Position of the ring in the ring list.

RepeatedRingVertex

A ring visits the same vertex twice.

Two indices at one position count as one vertex, and so does repeating the first index at the end to close the ring: a ring is closed implicitly.

Fields

ring: u32

Position of the ring in the ring list.

index: u32

The later of the two occurrences, as an input index.

FoldedRing

A ring doubles back on itself at a vertex.

Both neighbours of the vertex lie on one side of it on a common line, so the ring has a zero-width spike (or no area at all) there.

Fields

ring: u32

Position of the ring in the ring list.

index: u32

The vertex where the ring folds, as an input index.

MisnestedRing

The rings nest in a way that is neither inside nor outside: a region has a winding other than 0 or 1.

A hole outside every outer ring, a hole inside a hole, a hole listed twice and an outer ring inside another all end here. Rings (or a ring and itself) that cross between vertices are refused earlier, as CrossingConstraints.

Fields

ring: u32

The lowest-numbered ring that carries the boundary crossed into the region.

winding: i32

The winding of that region.

EmptyDomain

The rings enclose no triangle, so the domain is empty.

NonFinitePoint

An input point has a non-finite coordinate (NaN or infinite).

The orientation and incircle predicates are exact only for finite doubles; a non-finite one would read as exactly collinear and place a made-up edge, so the input is refused.

Fields

index: u32

Index of the first such point.

Trait Implementations

impl Clone for TriangulationError

fn clone(&self) -> TriangulationError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for TriangulationError

impl Debug for TriangulationError

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

Formats the value using the given formatter.

impl Display for TriangulationError

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

Formats the value using the given formatter.

impl Eq for TriangulationError

impl Error for TriangulationError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl PartialEq for TriangulationError

fn eq(&self, other: &TriangulationError) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for TriangulationError