refactor(es modules): modulize utils

src/utils/coordinateUtils.ts

@@ -0,0 +1,25 @@
+import {rn} from "./numberUtils";
+
+const {mapCoordinates, graphWidth, graphHeight} = window;
+
+function getLongitude(x: number, decimals = 2) {
+  return rn(mapCoordinates.lonW + (x / graphWidth) * mapCoordinates.lonT, decimals);
+}
+
+function getLatitude(y: number, decimals = 2) {
+  return rn(mapCoordinates.latN - (y / graphHeight) * mapCoordinates.latT, decimals);
+}
+
+export function getCoordinates(x: number, y: number, decimals = 2) {
+  return [getLongitude(x, decimals), getLatitude(y, decimals)];
+}
+
+// convert coordinate to DMS format
+export function toDMS(coord: number, type: "lat" | "lon") {
+  const degrees = Math.floor(Math.abs(coord));
+  const minutesNotTruncated = (Math.abs(coord) - degrees) * 60;
+  const minutes = Math.floor(minutesNotTruncated);
+  const seconds = Math.floor((minutesNotTruncated - minutes) * 60);
+  const cardinal = type === "lat" ? (coord >= 0 ? "N" : "S") : coord >= 0 ? "E" : "W";
+  return `${degrees}° ${minutes}′ ${seconds}″ ${cardinal}`;
+}