Features

Doing geospatial calculations requires feature types. This library provides a set of feature types for use in geospatial calculations, as well as a set of functions for working with them.

Geometry Types

The Feature class is the base class for all feature types.

Single Features

The Point class is a feature type for points.
The LineString class is a feature type for line strings.
The Polygon class is a feature type for polygons.

Multi Features

The MultiPoint class is a feature type for multi points.
The MultiLineString class is a feature type for multi line strings.
The MultiPolygon class is a feature type for multi polygons.

Geometry Collections

The FeatureCollection class is a feature type for feature collections.

Coordinates

The Coordinate class is a coordinate type for to denote one location with lat/long data.
The LinearRing class is a coordinate type for linear rings, which is a geometry type for polygons.
The BoundingBox class is a coordinate system for bounding boxes.

About Features

Each of the above feature classes has a toJson method that returns a GeoJSON Map of the feature, as well as a fromJson method that creates a feature from a GeoJSON Map.

Each of the above feature classes also has a toWKT method that returns a WKT String of the feature, and a fromWKT method that creates a feature from a WKT String.

Every feature has an explode method that returns a List of Points used to create the feature.

Every Multi feature type has an flatten method that returns a List of the individual features, as well as a union method that returns a Feature of the union of the individual features.

Examples of how to use the above feature classes are shown below.

import 'package:geodart/geometries.dart';

// Create a point feature
Point point = Point(
  Coordinate(1.0, 2.0)
  properties: {
    'name': 'Point',
    'description': 'A point feature',
});

// Create a line string feature
LineString line = LineString([
    Coordinate(1.0, 2.0),
    Coordinate(3.0, 4.0),
    Coordinate(5.0, 6.0),
    Coordinate(7.0, 8.0),
    Coordinate(9.0, 10.0),
  ],
  properties: {
    'name': 'LineString',
    'description': 'A line string feature',
  }
);

// Create a polygon feature
Polygon poly = Polygon([
  LinearRing([
    Coordinate(1.0, 2.0),
    Coordinate(3.0, 4.0),
    Coordinate(5.0, 6.0),
    Coordinate(7.0, 8.0),
    Coordinate(9.0, 11.0),
    Coordinate(1.0, 2.0)
  ])],
  properties: {
    'name': 'Polygon',
    'description': 'A polygon feature',
  }
);

// Create a multi point feature
MultiPoint multiPoint = MultiPoint([
    Coordinate(1.0, 2.0),
    Coordinate(3.0, 4.0),
    Coordinate(5.0, 6.0),
  ]),
  properties: {
    'name': 'MultiPoint',
    'description': 'A multi point feature',
  }
);

geometries library