Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
## Earcut
The fastest and smallest JavaScript polygon triangulation library. 2.5KB gzipped.
[](https://travis-ci.org/mapbox/earcut)
[](https://coveralls.io/r/mapbox/earcut?branch=master)
[](http://isitmaintained.com/project/mapbox/earcut "Average time to resolve an issue")
[](http://isitmaintained.com/project/mapbox/earcut "Percentage of issues still open")
[](https://github.com/mourner/projects)
#### The algorithm
The library implements a modified ear slicing algorithm,
optimized by [z-order curve](http://en.wikipedia.org/wiki/Z-order_curve) hashing
and extended to handle holes, twisted polygons, degeneracies and self-intersections
in a way that doesn't _guarantee_ correctness of triangulation,
but attempts to always produce acceptable results for practical data.
It's based on ideas from
[FIST: Fast Industrial-Strength Triangulation of Polygons](http://www.cosy.sbg.ac.at/~held/projects/triang/triang.html) by Martin Held
and [Triangulation by Ear Clipping](http://www.geometrictools.com/Documentation/TriangulationByEarClipping.pdf) by David Eberly.
#### Why another triangulation library?
The aim of this project is to create a JS triangulation library
that is **fast enough for real-time triangulation in the browser**,
sacrificing triangulation quality for raw speed and simplicity,
while being robust enough to handle most practical datasets without crashing or producing garbage.
Some benchmarks using Node 0.12:
(ops/sec) | pts | earcut | libtess | poly2tri | pnltri | polyk
------------------| ---- | --------- | -------- | -------- | --------- | ------
OSM building | 15 | _795,935_ | _50,640_ | _61,501_ | _122,966_ | _175,570_
dude shape | 94 | _35,658_ | _10,339_ | _8,784_ | _11,172_ | _13,557_
holed dude shape | 104 | _28,319_ | _8,883_ | _7,494_ | _2,130_ | n/a
complex OSM water | 2523 | _543_ | _77.54_ | failure | failure | n/a
huge OSM water | 5667 | _95_ | _29.30_ | failure | failure | n/a
The original use case it was created for is [Mapbox GL](https://www.mapbox.com/mapbox-gl), WebGL-based interactive maps.
If you want to get correct triangulation even on very bad data with lots of self-intersections
and earcut is not precise enough, take a look at [libtess.js](https://github.com/brendankenny/libtess.js).
#### Usage
```js
var triangles = earcut([10,0, 0,50, 60,60, 70,10]); // returns [1,0,3, 3,2,1]
```
Signature: `earcut(vertices[, holes, dimensions = 2])`.
* `vertices` is a flat array of vertex coordinates like `[x0,y0, x1,y1, x2,y2, ...]`.
* `holes` is an array of hole _indices_ if any
(e.g. `[5, 8]` for a 12-vertex input would mean one hole with vertices 5–7 and another with 8–11).
* `dimensions` is the number of coordinates per vertex in the input array (`2` by default).
Each group of three vertex indices in the resulting array forms a triangle.
```js
// triangulating a polygon with a hole
earcut([0,0, 100,0, 100,100, 0,100, 20,20, 80,20, 80,80, 20,80], [4]);
// [3,0,4, 5,4,0, 3,4,7, 5,0,1, 2,3,7, 6,5,1, 2,7,6, 6,1,2]
// triangulating a polygon with 3d coords
earcut([10,0,1, 0,50,2, 60,60,3, 70,10,4], null, 3);
// [1,0,3, 3,2,1]
```
If you pass a single vertex as a hole, Earcut treats it as a Steiner point.
If your input is a multi-dimensional array (e.g. [GeoJSON Polygon](http://geojson.org/geojson-spec.html#polygon)),
you can convert it to the format expected by Earcut with `earcut.flatten`:
```js
var data = earcut.flatten(geojson.geometry.coordinates);
var triangles = earcut(data.vertices, data.holes, data.dimensions);
```
After getting a triangulation, you can verify its correctness with `earcut.deviation`:
```js
var deviation = earcut.deviation(vertices, holes, dimensions, triangles);
```
Returns the relative difference between the total area of triangles and the area of the input polygon.
`0` means the triangulation is fully correct.
#### Install
NPM and Browserify:
```bash
npm install earcut
```
Browser builds on CDN:
- [development build](https://unpkg.com/[email protected]/dist/earcut.dev.js)
- [minified production build](https://unpkg.com/[email protected]/dist/earcut.min.js)
Running tests:
```bash
npm test
```
#### Ports to other languages
- [mapbox/earcut.hpp](https://github.com/mapbox/earcut.hpp) (C++11)
- [earcut4j/earcut4j](https://github.com/earcut4j/earcut4j) (Java)
- [the3deers/earcut-java](https://github.com/the3deers/earcut-java) (Java)
- [Larpon/earcut](https://github.com/Larpon/earcut) (V)
- [Cawfree/earcut-j](https://github.com/Cawfree/earcut-j) (Java, outdated)
#### Changelog
##### 2.2.2 (Jan 21, 2020)
- Fixed yet another rare race condition when a hole shared an edge with an outer ring.
##### 2.2.1 (Sep 19, 2019)
- Fixed another rare case with touching holes.
##### 2.2.0 (Sep 18, 2019)
- Fixed a handful of rare race conditions.
##### 2.1.5 (Feb 5, 2019)
- Fixed a race condition with coincident holes that could lead to bad triangulation.
##### 2.1.4 (Dec 4, 2018)
- Fixed a race condition that could lead to a freeze on degenerate input.
##### 2.1.3 (Jan 4, 2018)
- Improved performance for bigger inputs (5-12%).
##### 2.1.2 (Oct 23, 2017)
- Fixed a few race conditions where bad input would cause an error.
##### 2.1.1 (Mar 17, 2016)
- Fixed a rare race condition where the split routine would choose bad diagonals.
- Fixed a rare race condition in the "cure local intersections" routine.
- Fixed a rare race condition where a hole that shares a point with the outer ring would be handled incorrectly.
- Fixed a bug where a closing point wouldn't be filtered as duplicate, sometimes breaking triangulation.
##### 2.1.0 (Mar 11, 2016)
- Added `earcut.deviation` function for verifying correctness of triangulation.
- Added `earcut.flatten` function for converting GeoJSON-like input into a format Earcut expects.
##### 2.0.9 (Mar 10, 2016)
- Fixed a rare race condition where a hole would be handled incorrectly.
##### 2.0.8 (Jan 19, 2016)
- Fixed a rare race condition with a hole touching outer ring.
##### 2.0.7 (Nov 18, 2015)
- Changed the algorithm to avoid filtering colinear/duplicate vertices unless it can't triangulate the polygon otherwise.
Improves performance on simpler shapes and fixes some 3D use cases.
##### 2.0.6 (Oct 26, 2015)
- Improved robustness and reliability of the triangulation algorithm.
- Improved performance by up to 15%.
- Significantly improved source code clarity.
##### 2.0.5 (Oct 12, 2015)
- Fixed a z-curve hashing bug that could lead to unexpected results in very rare cases involving shapes with lots of points.
##### 2.0.4 (Oct 8, 2015)
- Fixed one more extremely rare race condition, lol!
##### 2.0.3 (Oct 8, 2015)
- Fixed yet another rare race condition (multiple holes connected with colinear bridges).
- Fixed crash on empty input.
##### 2.0.2 (Jul 8, 2015)
- Fixed one more rare race condition with a holed polygon.
##### 2.0.1 (May 11, 2015)
- Added Steiner points support.
##### 2.0.0 (Apr 30, 2015)
- **Breaking**: changed the API to accept a flat input array of vertices with hole indices and return triangle indices.
It makes the indexed output much faster than it was before (up to 30%) and improves memory footprint.
##### 1.4.2 (Mar 18, 2015)
- Fixed another rare edge case with a tiny hole in a huge polygon.
##### 1.4.1 (Mar 17, 2015)
- Fixed a rare edge case that led to incomplete triangulation.
##### 1.4.0 (Mar 9, 2015)
- Fixed indexed output to produce indices not multiplied by dimension and work with any number of dimensions.
##### 1.3.0 (Feb 24, 2015)
- Added a second argument to `earcut` that switches output format to flat vertex and index arrays if set to `true`.
##### 1.2.3 (Feb 10, 2015)
- Improved performance (especially on recent v8) by avoiding `Array` `push` with multiple arguments.
##### 1.2.2 (Jan 27, 2015)
- Significantly improved performance for polygons with self-intersections
(e.g. big OSM water polygons are now handled 2-3x faster)
##### 1.2.1 (Jan 26, 2015)
- Significantly improved performance on polygons with high number of vertices
by using z-order curve hashing for vertex lookup.
- Slightly improved overall performance with better point filtering.
##### 1.1.0 (Jan 21, 2015)
- Improved performance on polygons with holes by switching from Held to Eberly hole elimination algorithm
- More robustness fixes and tests
##### 1.0.1 — 1.0.6 (Jan 20, 2015)
- Various robustness improvements and fixes.
##### 1.0.0 (Jan 18, 2015)
- Initial release.
