Geo::OSM::Tiles(3pm)					User Contributed Perl Documentation				      Geo::OSM::Tiles(3pm)

NAME

       Geo::OSM::Tiles - Calculate tile numbers for OpenStreetMap

SYNOPSIS

	 use Geo::OSM::Tiles qw( :all );

	 $zoom = 13;
	 $lat = 49.60055;
	 $lon = 11.01296;
	 $tilex = lon2tilex($lon, $zoom);
	 $tiley = lat2tiley($lat, $zoom);
	 $path = tile2path($tilex, $tiley, $zoom);
	 $tileurl = "http://tile.openstreetmap.org/$path";

DESCRIPTION

       This module provides functions for calculating the path to a map tile at OpenStreetMap out of geographic coordinates.  The path of a tile
       at OSM has the form "$zoom/$tilex/$tiley.png".  The numbering scheme is documented in the OSM wiki, see the link below.

   "lon2tilex($lon, $zoom)"
       Returns $tilex for the tile at longitude $lon and zoom level $zoom.  The longitude must be in the range "-180.0 <= $lon < 180.0".  The zoom
       level must be a non-negative integer.

   "lat2tiley($lat, $zoom)"
       Returns $tiley for the tile at latitude $lat and zoom level $zoom.  The latitude must be in the range "-85.0511 <= $lat <= 85.0511".  The
       zoom level must be a non-negative integer.

   "tile2path($tilex, $tiley, $zoom)"
       Composes the path to the tile at $tilex, $tiley, and $zoom at the OSM server.  $tilex and $tiley must be integers in the range
       "0..2**$zoom-1".  The supported range of zoom levels depends on the tile server.  The maximum zoom for the Osmarender layer is 17, it is 18
       for the Mapnik layer.

   "checklonrange($lonmin, $lonmax)"
       Checks whether $lonmin and $lonmax are within the allowed range of the longitude argument to "lon2tilex".  Returns "($lonmin, $lonmax)"
       unchanged if they are ok or corrected values if not.

   "checklatrange($latmin, $latmax)"
       Checks whether $latmin and $latmax are within the allowed range of the latitude argument to "lat2tiley".  Returns "($latmin, $latmax)"
       unchanged if they are ok or corrected values if not.

SEE ALSO

       <http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames>

AUTHOR

       Rolf Krahl <rotkraut@cpan.org>

COPYRIGHT AND LICENCE

       Copyright (C) 2008-2010 by Rolf Krahl

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or,
       at your option, any later version of Perl 5 you may have available.

perl v5.14.2							    2010-05-15						      Geo::OSM::Tiles(3pm)