npm package: @ngageoint/mgrs-js
Description: MGRS Javascript
Author: NGA
Latest version: 1.0.0

# MGRS Javascript

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#### Military Grid Reference System Lib ####

The MGRS Library was developed at the [National Geospatial-Intelligence Agency (NGA)](http://www.nga.mil/) in collaboration with [BIT Systems](https://www.caci.com/bit-systems/). The government has "unlimited rights" and is releasing this software to increase the impact of government investments by providing developers with the opportunity to take things in new directions. The software use, modification, and distribution rights are stipulated within the [MIT license](http://choosealicense.com/licenses/mit/).

### Pull Requests ###
If you'd like to contribute to this project, please make a pull request. We'll review the pull request and discuss the changes. All pull request contributions to this project will be released under the MIT license.

Software source code previously released under an open source license and then modified by NGA staff is considered a "joint work" (see 17 USC § 101); it is partially copyrighted, partially public domain, and as a whole is protected by the copyrights of the non-government authors and must be released according to the terms of the original open source license.

### About ###

[MGRS](http://ngageoint.github.io/mgrs-js/) is a Javascript library providing Military Grid Reference System functionality, a geocoordinate standard used by NATO militaries for locating points on Earth.

#### Coordinates ####

```javascript
    const mgrs = MGRS.parse('33XVG74594359');
    const point = mgrs.toPoint();
    const pointMeters = point.toMeters();
    const utm = mgrs.toUTM();
    const utmCoordinate = utm.toString();
    const point2 = utm.toPoint();

    const mgrs2 = MGRS.parse('33X VG 74596 43594');

    const latitude = 63.98862388;
    const longitude = 29.06755082;
    const point3 = Point.point(longitude, latitude);
    const mgrs3 = MGRS.from(point3);
    const mgrsCoordinate = mgrs3.toString();
    const mgrsGZD = mgrs3.coordinate(GridType.GZD);
    const mgrs100k = mgrs3.coordinate(GridType.HUNDRED_KILOMETER);
    const mgrs10k = mgrs3.coordinate(GridType.TEN_KILOMETER);
    const mgrs1k = mgrs3.coordinate(GridType.KILOMETER);
    const mgrs100m = mgrs3.coordinate(GridType.HUNDRED_METER);
    const mgrs10m = mgrs3.coordinate(GridType.TEN_METER);
    const mgrs1m = mgrs3.coordinate(GridType.METER);

    const utm2 = UTM.from(point3);
    const mgrs4 = utm2.toMGRS();

    const utm3 = UTM.parse('18 N 585628 4511322');
    const mgrs5 = utm3.toMGRS();
```

#### Draw Tile Template ####

See [mgrs-android](https://github.com/ngageoint/mgrs-android) for a concrete example

```javascript
 // GridTile tile = ...;

  const grids = Grids.create();

  const zoomGrids = grids.getGrids(tile.getZoom());
  if (zoomGrids && zoomGrids.hasGrids()) {
    const gridRange = GridZones.getGridRange(tile.getBounds()!);

    for (const grid of zoomGrids) {
      // draw this grid for each zone
      for (const zone of gridRange) {
        const lines = grid.getLinesFromGridTile(tile, zone);
        if (lines) {
          const pixelRange = zone.getBounds().getPixelRangeFromTile(tile);
          for (const line of lines) {
            const pixel1 = line.getPoint1().getPixelFromTile(tile);
            const pixel2 = line.getPoint2().getPixelFromTile(tile);
            // Draw line
          }
        }

        const labels = grid.getLabelsFromGridTile(tile, zone);
        if (labels) {
          for (const label of labels) {
            const pixelRange = label.getBounds()?.getPixelRangeFromTile(tile);
            const centerPixel = label.getCenter()?.getPixelFromTile(tile);
            // Draw label
          }
        }
      }
    }
  }
```

### Remote Dependencies ###

* [Grid Javascript](https://github.com/ngageoint/grid-js) (The MIT License (MIT)) - Grid Library