triangulate-polyline

Triangulates a complex polygon

Usage no npm install needed!

<script type="module">
  import triangulatePolyline from 'https://cdn.skypack.dev/triangulate-polyline';
</script>

README

triangulate-polyline

Triangulates a polygon with holes encoded as a list of loops.

Example

var triangulate = require("triangulate-polyline")

var positions = [
  [-2, -2],
  [ 2, -2],
  [ 2,  2],
  [-2,  2],
  [-1, -1],
  [ 1, -1],
  [ 1,  1],
  [-1,  1]
]

var loops = [
  [0, 1, 2, 3],
  [4, 5, 6, 7]
]

console.log(triangulate(loops, positions))

Example output:

[ [ 3, 7, 2 ],
  [ 3, 0, 7 ],
  [ 0, 4, 7 ],
  [ 4, 0, 1 ],
  [ 5, 4, 1 ],
  [ 6, 5, 1 ],
  [ 6, 1, 2 ],
  [ 7, 6, 2 ] ]

Install

npm install triangulate-polyline

API

require("triangulate-polyline")(loops, positions)

Triangulates a complex polygon

  • loops is a list of vertices of the polygon, where each vertex is represented as an index into positions
  • positions is a list of vertex positions encoded, each represented by a length 2 array

Returns A list of triangles represented by triples of indices of position indices.

Note This library is built on top of poly2tri, which is not robust. Points which are close together or near the boundary of other loops may be incorrectly classified and could result in broken triangulations.

Credits

(c) 2014 Mikola Lysenko. MIT License