flutter_map_rastercoords

A flutter_map plugin for displaying large, non-geographical images as tiled maps using a simple coordinate reference system. Tiles should be generated using gdal2tiles with the --xyz and -p raster options.

Inspired from leaflet-rastercoords.

Features

• Provides utilities to convert between pixel coordinates and LatLng.
• Helper utilities for flutter_map setup, including:
  • getMaxBounds() for constraining the map view.
  • zoom property that returns the optimal zoom level based on image dimensions.

Usage

1. Generate map tiles from your "large" image using gdal2tiles.py

   gdal2tiles.py --xyz -p raster -z 0-3 -w none <image> <tiles dir> 

2. Serve the generated tiles locally, for example using serve

   serve -l 8000 

3. Add flutter_map_rastercoords to your pubspec.yaml:

   dependencies: flutter_map_rastercoords: ^0.0.1 

4. Create a RasterCoords instance:

    final rc = RasterCoords(width: 1280, height: 1280); 

5. Use it in your FlutterMap:

   Widget build(BuildContext context) { return FlutterMap( options: MapOptions( // for non-geographical maps crs: CrsSimple(), // initialize with map on center initialCenter: rc.pixelToLatLng(x: 1280 / 2, y: 1280 / 2), // optimal zoom maxZoom: rc.zoom, minZoom: 1, initialZoom: 1, // set max bounds cameraConstraint: CameraConstraint.containCenter( bounds: rc.getMaxBounds(), ), ), children: [ TileLayer( // URL template for your locally hosted tiles urlTemplate: 'http://localhost:8000/map_tiles/{z}/{x}/{y}.png', ), ], ); }