Crate stripack 

STRIPACK

Delaunay Triangulation on the Unit Sphere.

A safe Rust wrapper for the STRIPACK library, providing Delaunay triangulation of points distributed on the surface of a unit sphere.

Overview

This crate provides algorithms for creating and manipulating Delaunay triangulations on spherical surfaces. A Delaunay triangulation maximizes the minimum angle of all triangles, making it optimal for interpolation and nearest-neighbor queries.

Features

• Triangulation Construction: Build Delaunay triangulations from sets of points on the unit sphere
• Dynamic Operations: Add or remove nodes while maintaining the Delaunay property
• Triangle Mesh Extraction: Get triangle indices, neighbor information, and edge data
• Voronoi Diagrams: Generate Voronoi cells (dual of Delaunay triangulation)
• Point Location: Find which triangle contains a given point
• Nearest Neighbor Queries: Find the k-nearest nodes to any point or node
• Boundary Detection: Identify boundary nodes for hemispherical data sets
• Geometric Utilities: Circumcenters, spherical triangle areas, coordinate conversions

Quick Start

use stripack::DelaunayTriangulation;

// Create triangulation from unit vectors
let x = vec![1.0, 0.0, 0.0, 0.0];
let y = vec![0.0, 1.0, 0.0, 0.0];
let z = vec![0.0, 0.0, 1.0, 1.0];

let triangulation = DelaunayTriangulation::new(x, y, z)?;

// Extract triangle mesh
let mesh = triangulation.triangle_mesh()?;

// Find nearest node to a point
let nearest = triangulation.nearest_node(&[1.0, 0.0, 0.0], 0)?;

Main Types

• DelaunayTriangulation: The primary structure representing a triangulation
• MeshData: Triangle mesh with indices, neighbors, and positions
• VoronoiCell: Circumcenter and radius information for Voronoi diagrams
• LocationInfo: Result of point location queries
• NearestNode: Index and distance for nearest neighbor queries

Safety

This crate provides a memory-safe wrapper around the STRIPACK Fortran library. All FFI calls are encapsulated and exposed through a safe, idiomatic Rust API.

Coordinate Systems

Points must lie on the unit sphere (x² + y² + z² = 1). Helper functions are provided for converting between Cartesian and spherical coordinates.

Performance

Expected O(N log N) time complexity for construction with randomly ordered nodes. Worst case O(N²) if nodes are ordered (e.g., by latitude).

See Also

• STRIPACK Documentation
• stripack-sys: Low-level FFI bindings

Structs

BoundaryInfo

The boundary nodes for a triangulation.

DelaunayTriangulation

A Delaunay triangulation on the unit sphere.

MeshData

The mesh data for the triangulation.

NearestNode

Information about the nearest node

NodeDeletionInfo

The information related to the new triangulation created by deleting a node.

SphericalCoordinates

Coordinates on a sphere.

VoronoiCell

Information about a Voronoi cell.

Enums

AddNodeError

CircumcenterError

DeleteNodeError

ForceAdjacentError

InsideError

LocationInfo

NearestNodeError

TriangleMeshError

TriangulationError

VoronoiCellError

Functions

arc_cosine

Computes the arc cosine with input truncated in the range [-1, 1].

areas

Computes the areas of a spherical triangle on the unit sphere.

cartesian_coordinates

Transform spherical coordinates into Cartesian coordinates.

circumcenter

Returns the circumcenter of a spherical triangle.

spherical_coordinates

Converts from Cartesian to spherical coordinates (latitude, longitude, radius).