https://github.com/hendrixfan/delaunator-ruby

Delaunay triangulation of 2D points. A Ruby Port
https://github.com/hendrixfan/delaunator-ruby

2d delaunay delaunay-triangulation geometry triangulation

Last synced: about 1 month ago
JSON representation

Delaunay triangulation of 2D points. A Ruby Port

• Host: GitHub
• URL: https://github.com/hendrixfan/delaunator-ruby
• Owner: hendrixfan
• License: mit
• Created: 2019-12-05T21:21:47.000Z (about 5 years ago)
• Default Branch: master
• Last Pushed: 2020-03-04T09:38:17.000Z (almost 5 years ago)
• Last Synced: 2024-11-09T05:20:11.007Z (about 1 month ago)
• Topics: 2d, delaunay, delaunay-triangulation, geometry, triangulation
• Language: Ruby
• Homepage:
• Size: 17.6 KB
• Stars: 10
• Watchers: 4
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.txt

Awesome Lists containing this project

README

        
[![Gem Version](https://badge.fury.io/rb/delaunator.svg)](https://badge.fury.io/rb/delaunator)

[![Build Status](https://travis-ci.com/hendrixfan/delaunator-ruby.svg?branch=master)](https://travis-ci.com/hendrixfan/delaunator-ruby)

# Delaunay Triangulation

This is a port of [Mapbox's Delaunator project](https://github.com/mapbox/delaunator).

## Installation

Add this line to your application's Gemfile:

```ruby

gem 'delaunator'

```

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install delaunator

## Usage

`Delaunator.triangulate()` returns an array of triangle vertex indices (each group of three numbers forms a triangle). All triangles are directed counterclockwise.

```ruby

points = [[382, 302], [382, 328], [382, 205], [623, 175], [382, 188], [382, 284], [623, 87], [623, 341], [141, 227]]

triangles = Delaunator.triangulate(points)

# => [2, 3, 4, 2, 5, 3, 5, 7, 3, 3, 6, 4, 0, 7, 5, 1, 7, 0, 0, 8, 1, 5, 8, 0, 2, 8, 5, 4, 8, 2, 6, 8, 4]

```

You can then use these indices to get the coordinates of each triangle:

```ruby

(0..triangles.length-1).step(3) do |i|

    ax, ay = points[triangles[i]]

    bx, by = points[triangles[i + 1]]

    cx, cy = points[triangles[i + 2]]

    # (ax, ay), (bx, by), (cx, cy) are your triangle points

    ...

```

After implementing your own render function you can show the edges of the Delaunay triangulation:

![image](https://user-images.githubusercontent.com/19203626/71546247-4c963600-2995-11ea-948f-5fec1d7982ea.png)

## Development

After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).

## Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/hendrixfan/delaunator-ruby.

## License

The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).