MapBundle.Mali 0.1.0

MapBundle

Bundled, offline map data for .NET apps — borders, cities, waterways and base layers — shipped as FlatGeobuf inside NuGet packages. Most data is derived from OpenStreetMap under the Open Database License (ODbL); the cities, rivers and lakes layers come from Natural Earth (public domain).

Packages

Install the core package plus the area required:

dotnet add package MapBundle.Monaco

By default a data package copies its FlatGeobuf files into a maps/<Region> folder beside the application at build time; the MapBundle core reads them from there. When FlatGeobuf is not the desired format, the data can instead be converted to another format and/or rendered to an image at build time.

Usage

<a id='snippet-usage'></a>

var map = Maps.Open().Load("Monaco");

var borders = map.Borders;        // country polygons
var cities = map.Cities;          // populated places
var states = map.StatesProvinces; // admin-1 polygons
var rivers = map.Rivers;          // rivers
// also: map.Lakes, map.Coastline, map.Land, map.Ocean

^{<a href='/src/Tests/Snippets.cs#L7-L15' title='Snippet source file'>snippet source</a> | <a href='#snippet-usage' title='Start of snippet'>anchor</a>}

Layers are read on demand and returned as GeoConvert FeatureCollections (coordinates are WGS84 longitude/latitude).

Build-time format conversion and images

FlatGeobuf is the default on-disk format, but it is not always the right fit for a consumer. Setting a few MSBuild properties (in a .csproj, Directory.Build.props, or on the command line) converts a data package's layers — and/or renders a preview image — with GeoConvert at build time, instead of copying the raw .fgb. The output still lands in maps/<Region> next to the app.

<PropertyGroup>
  
  <MapBundleFormat>GeoJson</MapBundleFormat>
  
  <MapBundleRenderImages>true</MapBundleRenderImages>
</PropertyGroup>

Note: conversion and image rendering run as an MSBuild task targeting net10.0, so they require building with a .NET 10+ SDK's MSBuild (dotnet build / dotnet publish, or Visual Studio using a .NET 10 SDK). The default raw-copy path needs no task and works under any host.

Data options

Image options

Only used when MapBundleRenderImages is true; each is left at GeoConvert's own default when unset.

Layers

The MapLayer enum (a layer is omitted from a package when the source has nothing for that region):

• Borders — country polygons (OSM admin level 2)
• StatesProvinces — state/province polygons (OSM admin level 4 / ISO 3166-2)
• Cities — populated places (place=city/town)
• Rivers — major waterways (waterway=river)
• Lakes — lake and reservoir polygons (natural=water, reservoir)
• Coastline — coastlines (derived from the land outlines); omitted for landlocked countries
• Land / Ocean — global base polygons. Ocean is omitted for landlocked countries.

Roads, railways, buildings, land use and terrain are intentionally excluded.

Packages

Layer icons: 🗺️ Borders · 🏛️ StatesProvinces · 🏙️ Cities · 〰️ Rivers · 💧 Lakes · 🏖️ Coastline · 🟩 Land · 🌊 Ocean

World

Continents

Countries

Data sources

• Borders and StatesProvinces come from country-levels — OSM-derived, pre-simplified WGS84 boundaries keyed by ISO code.
• Cities, Rivers and Lakes come from Natural Earth (public domain, 1:10m) via the nvkelso/natural-earth-vector mirror. Cities are selected per region by ISO code; rivers and lakes are clipped to the region's bounding box.
• Land and Ocean come from osmdata.openstreetmap.de; Coastline is derived from the land polygons.

Regions

The region tree follows Geofabrik's download index: the continents and their countries. MapBundle.World merges every continent. Sub-country levels (US states, German Bundesländer) are not published. See src/Tests/Builder/Regions.cs.

Building the data packages

The builder lives in the test project (src/Tests/Builder/) and runs as an explicit test. It downloads the source data (cached locally by Replicant), filters and simplifies each region, exports FlatGeobuf and writes the .nupkg files into nugets/:

src/Tests/bin/Release/net10.0/Tests --treenode-filter "/*/*/PackageBuilder/Generate"

To validate the pipeline on a single region (default monaco) without building the whole tree:

MAPBUNDLE_SLICE=monaco src/Tests/bin/Debug/net10.0/Tests --treenode-filter "/*/*/PackageBuilder/Slice"

Geometry simplification and EPSG:3857→4326 reprojection use NetTopologySuite, a build-only dependency; the shipped MapBundle core depends only on GeoConvert.

License

The MapBundle core library is MIT. The data packages contain OpenStreetMap data and are licensed under the ODbL — © OpenStreetMap contributors.