topic Re: Is there a WebMercatorUtil class? in ArcGIS Runtime SDK for iOS Questions

Is there a WebMercatorUtil class?

MapEnglish — Mon, 10 May 2010 12:05:17 GMT

Hi:

Will there be a WebMercatorUtil class available in the iPhone API, similar to the Flex API? This is a popular and convenient class in the Flex API for taking lat/lon geocoding results and projecting them to Web Mercator for display on modern basemaps. Or do we need to use the AGSGeometryService task?

Trying to keep the lines of code to a minimum,
Matt English

Re: Is there a WebMercatorUtil class?

MikeQuetel — Sat, 11 Dec 2021 10:05:40 GMT

Hi:

Will there be a WebMercatorUtil class available in the iPhone API, similar to the Flex API? This is a popular and convenient class in the Flex API for taking lat/lon geocoding results and projecting them to Web Mercator for display on modern basemaps. Or do we need to use the AGSGeometryService task?

Trying to keep the lines of code to a minimum,
Matt English

If this is something you need now, here are a couple javascript functions that you could port to Obj C. I wouldn't go back to the server for that kind of thing if at all possible.

      function ll2meters(lat,lon) {
        // Converts given lat/lon in WGS84 Datum to XY in Spherical Mercator EPSG:900913
        var originShift = 2 * Pi() * 6378137 / 2.0;                     
        var ret = StructNew(); mx=0; my=0;
        mx = lon * originShift / 180.0;
        my = Log(Tan((90 + lat) * Pi() / 360.0 )) / (Pi() / 180.0);
        my = my * originShift / 180.0;
        ret.x = mx;
        ret.y = my; 
        return ret;
      }

      function meters2ll(mx,my) {
        // Converts XY point from Spherical Mercator EPSG:900913 to lat/lon in WGS84 Datum"
        var originShift = 2 * Pi() * 6378137 / 2.0;                     
        var ret=StructNew(); lon=0; lat=0;
        lon = (mx / originShift) * 180.0;
        lat = (my / originShift) * 180.0;
        lat = 180 / Pi() * (2 * Atan( Exp( lat * Pi() / 180.0)) - Pi() / 2.0);
        ret.lat = lat;
        ret.lon = lon;    
        return ret;
      }

Re: Is there a WebMercatorUtil class?

DiveshGoyal — Sat, 11 Dec 2021 10:05:42 GMT

A couple of global functions which you can use

AGSGeometryGeographicToWebMercator
AGSGeometryWebMercatorToGeographic

For some reason, the API ref is currently not picking up these global functions. We'll try to get that resolved.
_
Divesh

Re: Is there a WebMercatorUtil class?

JustinCarasick — Thu, 17 Mar 2011 02:26:01 GMT

very nice. thanks for sharing that tidbit.