A mixin for layers that wraps up the pieces neccesary to have a coordinate conversion for working with commercial APIs which use a spherical mercator projection. Using this layer as a base layer, additional layers can be used as overlays if they are in the same projection.
A layer is given properties of this object by setting the sphericalMercator property to true.
More projection information
Proj4 Text
+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs
WKT
900913=PROJCS[“WGS84 / Simple Mercator”, GEOGCS[“WGS 84”, DATUM[“WGS_1984”, SPHEROID[“WGS_1984”, 6378137.0, 298.257223563]], PRIMEM[“Greenwich”, 0.0], UNIT[“degree”, 0.017453292519943295], AXIS[“Longitude”, EAST], AXIS[“Latitude”, NORTH]], PROJECTION[“Mercator_1SP_Google”], PARAMETER[“latitude_of_origin”, 0.0], PARAMETER[“central_meridian”, 0.0], PARAMETER[“scale_factor”, 1.0], PARAMETER[“false_easting”, 0.0], PARAMETER[“false_northing”, 0.0], UNIT[“m”, 1.0], AXIS[“x”, EAST], AXIS[“y”, NORTH], AUTHORITY[“EPSG”,”900913”]]
Summary
| OpenLayers.Layer.SphericalMercator | A mixin for layers that wraps up the pieces neccesary to have a coordinate conversion for working with commercial APIs which use a spherical mercator projection. |
| Functions | |
| getExtent | Get the map’s extent. |
| initMercatorParameters | Set up the mercator parameters on the layer: resolutions, projection, units. |
| forwardMercator | Given a lon,lat in EPSG:4326, return a point in Spherical Mercator. |
| inverseMercator | Given a x,y in Spherical Mercator, return a point in EPSG:4326. |
| projectForward | Given an object with x and y properties in EPSG:4326, modify the x,y properties on the object to be the Spherical Mercator projected coordinates. |
| projectInverse | Given an object with x and y properties in Spherical Mercator, modify the x,y properties on the object to be the unprojected coordinates. |