Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/rowanwins/bentley-ottmann-intersections
A module to check if a polygon self-intersects using the bentley-ottmann algorithm
https://github.com/rowanwins/bentley-ottmann-intersections
Last synced: 11 days ago
JSON representation
A module to check if a polygon self-intersects using the bentley-ottmann algorithm
- Host: GitHub
- URL: https://github.com/rowanwins/bentley-ottmann-intersections
- Owner: rowanwins
- License: mit
- Created: 2019-08-08T13:25:40.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2023-01-04T09:30:14.000Z (almost 2 years ago)
- Last Synced: 2024-10-12T04:17:36.891Z (27 days ago)
- Language: JavaScript
- Homepage: https://rowanwins.github.io/bentley-ottmann-intersections/debug/index.html
- Size: 4.43 MB
- Stars: 7
- Watchers: 3
- Forks: 2
- Open Issues: 21
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# bentley-ottmann-intersections
**NOTE** For a faster and smaller module I recommend checking out [sweepline-intersections](https://github.com/rowanwins/sweepline-intersections)
A small module using the Bentley-Ottmann algorithm to detection self-intersections
## Install
````
npm install bentley-ottmann-intersections
````
## Documentation
Valid inputs: Geojson `Polygon`, `MultiPolygon`
````js
const findIntersections = require('bentley-ottmann-intersections')
const box = {type: 'Polygon', coordinates: [[[0, 0], [1, 0], [1, 1], [0, 1], [0, 0]]]}
findIntersections(box)
// returns array os intersection points
````
## Benchmarks
Tested against
- gpsi - https://www.npmjs.com/package/geojson-polygon-self-intersections
- isects - https://www.npmjs.com/package/2d-polygon-self-intersections
````
// Switzerland with kinks
// gpsi x 36.78 ops/sec ±2.03% (49 runs sampled)
// bentleyOttmannIntersections x 2,047 ops/sec ±1.79% (89 runs sampled)
// isects x 14.22 ops/sec ±1.73% (40 runs sampled)
// - Fastest is bentleyOttmannIntersections
// Simple Case
// gpsi x 246,005 ops/sec ±1.54% (90 runs sampled)
// bentleyOttmann x 535,293 ops/sec ±1.73% (95 runs sampled)
// - Fastest is bentleyOttmannIntersections
````
## Contributing
- For a live dev server run `npm run debug`.
- The geometry being tested can be modified in `debug/src/App.vue`
- There are a couple of test suites
- `npm run test` runs all tests
- `npm run test:e2e` does a general test that the correct number of self-intersections are found in the `test/fixtures` folder
- `npm run test:unit` is unit style tests to make sure functions & methods do the right thing
- these need some love
## Further Reading
- [Original paper](https://github.com/rowanwins/bentley-ottmann-intersections/blob/master/1979-Bentley.pdf)
- [Geom algorithms website](http://geomalgorithms.com/a09-_intersect-3.html#Bentley-Ottmann-Algorithm)
- [Lecture notes by M Smid from Carleton University](https://people.scs.carleton.ca/~michiel/lecturenotes/ALGGEOM/bentley-ottmann.pdf)