Google map path doesn't cross International Dateline using epoly.js

Question

I'm making a marker move from point A to point B by using the .GetPointDistance from epoly.js in a loop. It works fine as long as the shortest distance does not cross the Intl Dateline. If it does, like going from San Francisco, to Tokyo, it travels eastbound the long way around instead of crossing the pacific (Google polyline will draw it correctly) Here's my code

function myLoop () {
          setTimeout(function () {

            var point = flightPath.GetPointAtDistance(newDistance);
            marker.setPosition(point);

            if (newDistance < legDistance) {
              myLoop();
            } else {

              if (testArray.length > 0) {
                flightPathShadow.setMap(map);
                flightPath.setMap(map);

                x = testArray.shift();
                newDistance = 0;
                loopWrapper();
              }
            }

            oldDistance = newDistance;
            newDistance = newDistance + travelDistance;
            totalDistance = (totalDistance + travelDistance);
            var milesDistance = totalDistance*0.000621371;
            milesDistance = Math.round(milesDistance);
            milesDistance = addCommas(milesDistance);
            $("#dashboard").html("<h4>" + milesDistance + " miles traveled</h4>");

          }, travelTime)
        }

Here's the function in epoly.js

google.maps.Polygon.prototype.GetPointAtDistance = function(metres) {
  if (metres == 0) return this.getPath().getAt(0);
  if (metres < 0) return null;
  if (this.getPath().getLength() < 2) return null;
  var dist=0;
  var olddist=0;
  for (var i=1; (i < this.getPath().getLength() && dist < metres); i++) {
    olddist = dist;
    dist += this.getPath().getAt(i).distanceFrom(this.getPath().getAt(i-1));
  }
  if (dist < metres) {
    return null;
  }
  var p1= this.getPath().getAt(i-2);
  var p2= this.getPath().getAt(i-1);
  var m = (metres-olddist)/(dist-olddist);
  return new google.maps.LatLng( p1.lat() + (p2.lat()-p1.lat())*m, p1.lng() + (p2.lng()-p1.lng())*m);
}

Last I checked [epoly.js](http://econym.org.uk/gmap/epoly.htm) was a [Google Maps Javascript API v2](https://developers.google.com/maps/documentation/javascript/v2/reference) library. That version of the API has been deprecated and turned off for several years. What does **your** code look like? What version of the API are you using? — geocodezip, Jan 20 '15 at 14:26
Im using v3 and I'm using a ported version of epoly.js to work with v3... — starvingpilot, Jan 21 '15 at 06:06
If you add a point on the Intl Date line, it works [example](http://www.geocodezip.com/v3_animate_marker_xml.html?filename=CrossIntlDateLineX.xml) ([without that point, I see the issue](http://www.geocodezip.com/v3_animate_marker_xml.html?filename=CrossIntlDateLine.xml) — geocodezip, Jan 21 '15 at 06:47

score 1 · Accepted Answer · answered Jan 21 '15 at 18:28

1

If you add a point on the International Date Line, it works

example

Includes these points:

<point lat="37.77493" lng="-122.419416"/>
<point lat="39.614028" lng="-179.906751"/>
<point lat="39.904211" lng="116.407395"/>

answered Jan 21 '15 at 18:28

geocodezip

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Google map path doesn't cross International Dateline using epoly.js

1 Answers1