The flexible polyline encoding from heremaps is a lossy compressed representation of a list of coordinate pairs or coordinate triples.
It achieves that by:
- Reducing the decimal digits of each value.
- Encoding only the offset from the previous point.
- Using variable length for each coordinate delta.
- Using 64 URL-safe characters to display the result.
For more information, visit: https://github.com/heremaps/flexible-polyline
Add this line to your application's Gemfile:
gem 'flexible_polyline'
And then execute:
$ bundle install
Or install it yourself as:
$ gem install flexible_polyline
Encode:
FlexiblePolyline::Encoder.encode(third_dim: 1, precision: 8, third_dim_precision: 8, positions: [[-96.628241002595274, 34.155307026461529, 228.390420353746407]])
=> "B4gBnq_r-_R-suzyrGm_vgqxqB"
Decode:
FlexiblePolyline::Decoder.decode('B4gBnq_r-_R-suzyrGm_vgqxqB')
=>
{"header": {"precision": 8, "third_dim": 1, "third_dim_precision": 8}, "positions": [[-96.628241, 34.15530703, 228.39042035]]}
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 the created tag, and push the .gem
file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/ioki-mobility/flexible_polyline.
The gem is available as open source under the terms of the MIT License.