return new OpenLayers.LonLat(lon, lat);
}
-// for interacting with the PostGIS database which uses non spherical
-// Mercator. Taken from Freemap which in turn was taken from a standard
-// algorithm off the net.
-
-function lonLatToNonSphericalMercator(ll) {
- var custLat = ll.lat * (Math.PI/180);
- var a = 6378137;
- var b = 6356752.3142;
- var f = (a-b)/a;
- var e = Math.sqrt(2*f-Math.pow(f,2));
- custLat=a*Math.log(Math.tan(Math.PI/4+custLat/2)*
- Math.pow(( (1-e*Math.sin(custLat)) / (1+e*Math.sin(custLat))),e/2));
- custLon = ll.lon * (Math.PI/180) * 6378137;
- return new OpenLayers.LonLat (custLon,custLat);
-}
-
-function nonSphericalMercatorToLonLat(merc) {
- var lon_deg, lat_deg;
- var a = 6378137.0;
- var b = 6356752.3142;
- var k0 = 1.0;
- var t = 1.0 - b/a;
- var es = 2*t - t*t;
- var e = Math.sqrt(es);
- lon_deg = merc.lon;
- lat_deg = merc.lat;
- lon_deg /= a;
- lat_deg /= a;
- lon_deg /= k0;
- lat_deg = phi2(Math.exp(-lat_deg/k0), e);
- lon_deg *= (180/M_PI);
- lat_deg *= (180/M_PI);
- return new OpenLayers.LonLat(lon_deg,lat_deg);
-}
-
-function phi2 (ts,e) {
- var eccnth = 0.5*e;
- var Phi = (PI/2) - 2.0*Math.atan(ts);
- var dphi;
- var i=15;
- do {
- var con = e*Math.sin(Phi);
- dphi = (PI/2) - 2.0*Math.atan(ts*Math.pow((1.0-con)/(1.0+con),eccnth))
- - Phi;
- Phi += dphi;
- }
- while(Math.abs(dphi) > 0.0000000001 && --i);
- return Phi;
-}
-
function scaleToZoom(scale) {
return Math.log(360.0/(scale * 512.0)) / Math.log(2.0);
}