Class: UTM

// To calculate a line n(x,y) meter away from particular latitude and longitude…..where x is distance towards east west, y is distance towards north south
import {UTM} from '@int/geotoolkit/map/coordinatesystems/UTM';
import {Polygon} from '@int/geotoolkit/scene/shapes/Polygon';
const system = new UTM(15, false); // 15 UTM zone, north hemisphere ('true' for southern)
const origin = system.transform(-95.388718, 29.716131); // your lat/lon origin, Houston coordinates here
const coordsX = [100, -200, 300]; // your coordinates in meters from the 'origin' lat/long point
const newX = coordsX.map((x) => x + origin.getX());  // shifting relative to the initial point
... // same for the Y coordinates
const polygon = new Polygon({ // Your polygon to draw
'x': newX,
'y': newY
});

// To find the distance between the two lat/long points only by transforming them to UTM:
import {UTM} from '@int/geotoolkit/map/coordinatesystems/UTM';
import {Point} from '@int/geotoolkit/util/Point';
const system = new UTM(18, false);
const point1 = system.transform(-77.009003, 38.889931); // Washington
const point2 = system.transform(-75.165222, 39.952583); // Philadelphia
Point.getDistance(point1, point2); // 197744 meters
// You can also use the 'system' property in map layers for automatic conversion from one coordinate system to another

// To calculate the UTM zone dynamically:
const lat = 29.761993, lon = -95.366302; // your latitude/longitude for the origin point
const zone = Math.floor((lon + 180) / 6) % 60 + 1; // formula for UTM zone
const southern = (lat < 0); // calculate hemishere
const system = new UTM(zone, southern); // create system for the point
const point1 = system.transform(lon, lat); // transform point to UTM
const point2 = new Point(point1.x + dx, point1.y + dy); // dx, dy - distance between point1 & point2 in meters
system.inverseTransform(point2.x, point2.y, point2); // transform 'point2' back to lat/long coordinate system