ngx-open-map-wrapper/node_modules/@mapbox/vector-tile/README.md

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# vector-tile
This library reads [Mapbox Vector Tiles](https://github.com/mapbox/vector-tile-spec) and allows access to the layers and features.
## Example
```js
import {VectorTile} from '@mapbox/vector-tile';
import Protobuf from 'pbf';
const tile = new VectorTile(new Protobuf(data));
// Contains a map of all layers
tile.layers;
const landuse = tile.layers.landuse;
// Amount of features in this layer
landuse.length;
// Returns the first feature
landuse.feature(0);
```
Vector tiles contained in [serialtiles-spec](https://github.com/mapbox/serialtiles-spec)
are gzip-encoded, so a complete example of parsing them with the native
zlib module would be:
```js
import {VectorTile} from '@mapbox/vector-tile';
import Protobuf from 'pbf';
import {gunzipSync} from 'zlib';
const buffer = gunzipSync(data);
const tile = new VectorTile(new Protobuf(buffer));
```
## Install
To install:
npm install @mapbox/vector-tile
## API Reference
### VectorTile
An object that parses vector tile data and makes it readable.
#### Constructor
- **new VectorTile(protobuf[, end])** —
parses the vector tile data contained in the given [Protobuf](https://github.com/mapbox/pbf) object,
saving resulting layers in the created object as a `layers` property. Optionally accepts end index.
#### Properties
- **layers** (Object) &mdash; an object containing parsed layers in the form of `{<name>: <layer>, ...}`,
where each layer is a `VectorTileLayer` object.
### VectorTileLayer
An object that contains the data for a single vector tile layer.
#### Properties
- **version** (`Number`, default: `1`)
- **name** (`String`) &mdash; layer name
- **extent** (`Number`, default: `4096`) &mdash; tile extent size
- **length** (`Number`) &mdash; number of features in the layer
#### Methods
- **feature(i)** &mdash; get a feature (`VectorTileFeature`) by the given index from the layer.
### VectorTileFeature
An object that contains the data for a single feature.
#### Properties
- **type** (`Number`) &mdash; type of the feature (also see `VectorTileFeature.types`)
- **extent** (`Number`) &mdash; feature extent size
- **id** (`Number`) &mdash; feature identifier, if present
- **properties** (`Object`) &mdash; object literal with feature properties
#### Methods
- **loadGeometry()** &mdash; parses feature geometry and returns an array of
[Point](https://github.com/mapbox/point-geometry) arrays (with each point having `x` and `y` properties)
- **bbox()** &mdash; calculates and returns the bounding box of the feature in the form `[x1, y1, x2, y2]`
- **toGeoJSON(x, y, z)** &mdash; returns a GeoJSON representation of the feature. (`x`, `y`, and `z` refer to the containing tile's index.)