flutter_map_rastercoords 0.0.4

Flutter map utility library for non-geographic map projections using CRS Simple

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',
         ),
       ],
     );
   }