placement phase ready computation

traque-back/map_utils.js

@@ -0,0 +1,21 @@
+function getDistanceFromLatLon([lat1, lon1], [lat2, lon2]) {
+  var R = 6371; // Radius of the earth in km
+  var dLat = deg2rad(lat2-lat1);  // deg2rad below
+  var dLon = deg2rad(lon2-lon1); 
+  var a = 
+    Math.sin(dLat/2) * Math.sin(dLat/2) +
+    Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * 
+    Math.sin(dLon/2) * Math.sin(dLon/2)
+    ; 
+  var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
+  var d = R * c; // Distance in km
+  return d * 1000;
+}
+
+function deg2rad(deg) {
+  return deg * (Math.PI/180)
+}
+
+export function isInCircle(position, center, radius) {
+    return getDistanceFromLatLon(position, center) < radius;
+}