H3 Dart
If you're developing Flutter application, use should use h3_flutter instead.
The package allows to use Uber's H3 library directly in your Dart application
The package uses h3_ffi and h3_web under the hood.
final h3Factory = const H3Factory();
const kIsWeb = identical(0, 0.0); // taken from https://api.flutter.dev/flutter/foundation/kIsWeb-constant.html
final h3 = kIsWeb
? h3Factory.web()
: h3Factory.byPath('path/to/library.dll');
// Get hexagons in specified triangle.
final hexagons = h3.polyfill(
resolution: 5,
coordinates: [
GeoCoord(20.4522, 54.7104),
GeoCoord(37.6173, 55.7558),
GeoCoord(39.7015, 47.2357),
],
);
There are also few methods ported from JS library Geojson2H3, to access them you should instantiate Geojson2H3 class using const Geojson2H3(h3)
. It uses package:geojson2h3 internally.
Setup
If you're developing Flutter application, use should use h3_flutter instead.
VM
Get compiled h3 c library, depending on your platform it may have extension .so, .dll or any.
-
You can run
scripts/build_h3.sh
script, the compiled library will be ath3_ffi/c/h3lib/build/h3.so
-
You can compile it by yourself using C-code placed in
c
folder in this repository. It has small changes comparing to original Uber's code to make it more compatible with iOS and macOS versions ofh3_flutter
. This code is recompiled and used for testing everytime tests are launched, so it should work well. -
You can compile original Uber's code, which also should work well, just make sure you use correct version - https://github.com/uber/h3
Place your library somewhere and load it using final h3 = const H3Factory().byPath('path/to/library.dll');
Web
Web version is built on top of h3-js
, you have to import it.
Add next line to your index.html
:
<script defer src="https://unpkg.com/h3-js@3.7.2"></script>
Note, main.dart.js
import should go after this line
You can load the web version using final h3 = const H3Factory().web();