What's New

v1.6.2

2024-06-14T14:29:30Z
  • Swift 6 updates
  • Allow to merge tiles with different coordinates, for some weird use cases
  • Various small improvements and tidying up

MVTTools

Mapbox vector tiles (MVT) reader/writer for Swift.

Requirements

This package requires Swift 5.10 or higher (at least Xcode 14), and compiles on iOS (>= iOS 13), macOS (>= macOS 10.15), tvOS (>= tvOS 13), watchOS (>= watchOS 6) as well as Linux.

Installation with Swift Package Manager

dependencies: [
    .package(url: "https://github.com/Outdooractive/mvt-tools", from: "1.6.1"),
],
targets: [
    .target(name: "MyTarget", dependencies: [
        .product(name: "MVTTools", package: "mvt-tools"),
    ]),
]

This package uses the gis-tools library, and is being used by the mvt-postgis library, please have a look at them as well.

Command line tool

You can install the command line tool mvt locally to /usr/local/bin with

# ./install_mvt.sh

# mvt -h
OVERVIEW: A utility for inspecting and working with vector tiles.

USAGE: mvt <subcommand>

OPTIONS:
  --version               Show the version.
  -h, --help              Show help information.

SUBCOMMANDS:
  dump (default)          Print the vector tile as GeoJSON
  info                    Print information about the vector tile
  merge                   Merge two or more vector tiles
  query                   Query the features in a vector tile
  export                  Export the vector tile as GeoJSON
  import                  Import some GeoJSONs to a vector tile

  See 'mvt help <subcommand>' for detailed help.

Features

  • Load and write Mapnik Vector Tiles from/to disk or data objects (also handles gzipped input)
  • Export options: Zipped, buffered (in pixels or extents), simplified (in meters or extents)
  • Can dump a tile as a GeoJSON object
  • Supported projections: EPSG:4326, EPSG:3857 or none (uses the tile's coordinate space)
  • Fast search (supports indexing), either within a bounding box or with center and radius
  • Extract selected layers into a new tile
  • Merge two tiles into one
  • Can extract some infos from tiles like feature count, etc.
  • Command line tool

Usage

Load

import MVTTools

// Load
let mvtData = Data(contentsOf: URL(fileURLWithPath: "14_8716_8015.vector.mvt"))!
let tile = VectorTile(data: mvtData, x: 8716, y: 8015, z: 14, indexed: .hilbert)!

print(tile.isIndexed)
print(tile.layerNames.sorted())

let tileAsGeoJsonData: Data? = tile.toGeoJson(prettyPrinted: true)
...

let result = tile.query(at: Coordinate3D(latitude: 3.870163, longitude: 11.518585), tolerance: 100.0)
...

Write

import MVTTools

var tile = VectorTile(x: 8716, y: 8015, z: 14)!
var feature = Feature(Point(Coordinate3D(latitude: 3.870163, longitude: 11.518585)))
feature.properties = [
    "test": 1,
    "test2": 5.567,
    "test3": [1, 2, 3],
    "test4": [
        "sub1": 1,
        "sub2": 2
    ]
]

tile.setFeatures([feature], for: "test")

// Also have a look at ``VectorTile.ExportOptions``
let tileData = tile.data()
...

Playground

On macOS you can use a Swift Playground to inspect the MVTTools API such as layerNames & projection.

  • Load tile using MVTTools
  • Inspect the properties of the VectorTile

mvt dump

Print the vector tile as GeoJSON.

mvt works with a vector tile from local disk.

Example 1: Print information about the MVTTools test vector tile at zoom 14, at Yaoundé, Cameroon.

mvt dump Tests/MVTToolsTests/TestData/14_8716_8015.vector.mvt

mvt info

mvt info Tests/MVTToolsTests/TestData/14_8716_8015.vector.mvt

Result

Name               | Features | Points | LineStrings | Polygons | Unknown | Version
--------------------+----------+--------+-------------+----------+---------+--------
area_label         | 55       | 55     | 0           | 0        | 0       | 2      
barrier_line       | 4219     | 0      | 4219        | 0        | 0       | 2      
bridge             | 14       | 0      | 14          | 0        | 0       | 2      
building           | 5414     | 0      | 0           | 5414     | 0       | 2      
building_label     | 413      | 413    | 0           | 0        | 0       | 2      
...   
road               | 502      | 1      | 497         | 4        | 0       | 2      
road_label         | 309      | 0      | 309         | 0        | 0       | 2      

mvt works with a vector tile served from a web server.

Example 2: Inspect a MapLibre vector tile at zoom 2, with an extent showing Norway to India.

mvt info https://demotiles.maplibre.org/tiles/2/2/1.pbf

Result

Name      | Features | Points | LineStrings | Polygons | Unknown | Version
----------+----------+--------+-------------+----------+---------+--------
centroids | 104      | 104    | 0           | 0        | 0       | 2      
countries | 113      | 0      | 0           | 113      | 0       | 2      
geolines  | 4        | 0      | 4           | 0        | 0       | 2    

Contributing

Please create an issue or open a pull request with a fix

Dependencies (for development)

brew install protobuf swift-protobuf swiftlint

TODOs and future improvements

Links

License

MIT

Author

Thomas Rasch, Outdooractive

Description

  • Swift Tools 5.10.0
View More Packages from this Author

Dependencies

Last updated: Fri Jul 12 2024 17:16:06 GMT-0900 (Hawaii-Aleutian Daylight Time)