initial commit

server/math.js

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+export function bearing (latlng1, latlng2) {
+    const rad = Math.PI / 180
+    const lat1 = latlng1.gpsLatitude * rad
+    const lat2 = latlng2.gpsLatitude * rad
+    const lon1 = latlng1.gpsLongitude * rad
+    const lon2 = latlng2.gpsLongitude * rad
+    const y = Math.sin(lon2 - lon1) * Math.cos(lat2)
+    const x = Math.cos(lat1) * Math.sin(lat2) -
+        Math.sin(lat1) * Math.cos(lat2) * Math.cos(lon2 - lon1)
+
+    const bearing = ((Math.atan2(y, x) * 180 / Math.PI) + 360) % 360
+    return bearing >= 180 ? bearing - 360 : bearing
+}
+
+export function removeMilis(date) {
+    date.setSeconds(date.getSeconds(), 0);
+    return date;
+}