Provides a USNG "map collar" for OpenLayers maps. The spec USNG map collar is designed to be outside the map but this renders as a layer inside of the map.
To run the demo, install the dependencies and hit start!
npm install
npm start
Then navigate a browser to http://localhost:1234/
Live demo on GH Pages!
Install the package:
npm install usng-map-collar
import UsngGrid from 'usng-map-collar/UsngGrid';
Then add it as a layer to the OpenLayers Map.
The UTM zone lines, grid lines, and label styles can all be overridden by passing in options to the constructor.
-
zoneLineStyle
- Styling for the UTM zone lines. -
gridLineStyle
- Style for the USNG grid-lines. -
gridLabelStyle
- Style for the labels on the grid.
The constructor can be given an intervalFn
function which determines when
different grid intervals will be displayed. The following is the default:
const defaultIntervalFn = (resolution) => {
let interval = 1000000;
if (resolution < 0.02) {
interval = 1;
} else if (resolution < 0.25) {
interval = 10;
} else if (resolution < 2.5) {
interval = 100;
} else if (resolution < 25) {
interval = 1000;
} else if (resolution < 160) {
interval = 10000;
} else if (resolution < 2500) {
interval = 100000;
}
return interval;
};
(c) 2020 Dan "Ducky" Little, MIT License (see LICENSE file for details).