coomsie · December 6, 2011 19:14
diff --git a/downloadosmtilestosqlite.pl b/downloadosmtilestosqlite.pl
 #! /usr/bin/perl


 #	2011
 #	 added a few mods to script to allow to be pushed into sqlite
 #		coomsie at gmail.com

 use 5.006001;
 use strict;
 use warnings;
 use Geo::OSM::Tiles qw( :all );
 use LWP::UserAgent;
 use YAML qw( DumpFile LoadFile );
 use File::Path;
 use File::Basename;
 use File::Spec;
 use Cwd qw(cwd);
 use Getopt::Long;

 # IKC addtions
 use DBI;
 use MIME::Base64;

 my $db = DBI->connect("dbi:SQLite:dbname=0000000000000001.db",
                        "","");

 my $cursor;
 my @rec;

 #$db->do("DROP TABLE IF EXISTS 'tiles';");
 $db->do("CREATE TABLE IF NOT EXISTS tiles (provider TEXT, x INT, y INT, z INT, timestamp REAL, data BLOB);");
 #$db->do("DROP TABLE IF EXISTS '__WebKitDatabaseInfoTable__';");
 $db->do("CREATE TABLE IF NOT EXISTS __WebKitDatabaseInfoTable__ (key TEXT NOT NULL ON CONFLICT FAIL UNIQUE ON CONFLICT REPLACE,value TEXT NOT NULL ON CONFLICT FAIL);");
 $db->do("INSERT INTO '__WebKitDatabaseInfoTable__' VALUES('WebKitDatabaseVersionKey','1.0');");

 #$db->do("DROP TABLE IF EXISTS 'ini';");
 $db->do("CREATE TABLE IF NOT EXISTS ini (key TEXT, value TEXT);");
 $db->do("INSERT INTO 'ini' VALUES('lat','0.0');");
 $db->do("INSERT INTO 'ini' VALUES('lon','0.0');");
 $db->do("INSERT INTO 'ini' VALUES('zoom','0.0');");

 #

 our $linkrgoffs = 350.0;

 our $usage = qq{Usage: 
   $0 --latitude=d[:d] --longitude=d[:d] --zoom=z[:z] [--quiet] [--baseurl=url] [--destdir=dir] [--dumptilelist=filename]
   $0 --link=url [--latitude=d[:d]] [--longitude=d[:d]] [--zoom=z[:z]] [--quiet] [--baseurl=url] [--destdir=dir] [--dumptilelist=filename]
   $0 --loadtilelist=filename
 };

 our %opt = (
    latitude => undef,
    longitude => undef,
    zoom => undef,
    link => undef,
    quiet => undef,
    baseurl => "http://tile.openstreetmap.org",
    destdir => cwd,
    dumptilelist => undef,
    loadtilelist => undef,
 );

 die "$usage\n"
    unless GetOptions(\%opt,
 		      "latitude=s", "longitude=s", "zoom=s", "link=s",
 		      "quiet", "baseurl=s", "destdir=s", 
 		      "dumptilelist=s", "loadtilelist=s") &&
 	   @ARGV == 0;

 sub selecttilescmdline;
 sub downloadtiles;
 sub parserealopt;
 sub parseintopt;
 sub downloadtile;


 # List of tiles scheduled for download.
 # Format:
 # $tilelist = {
 #     zoomlevel => [
 # 	{
 # 	    xyz => [ tx, ty, tz ],
 # 	},
 # 	{
 # 	    xyz => [ tx, ty, tz ],
 # 	},
 # 	...
 #     ],
 #     zoomlevel => [
 # 	{
 # 	    xyz => [ tx, ty, tz ],
 # 	},
 # 	{
 # 	    xyz => [ tx, ty, tz ],
 # 	},
 # 	...
 #     ],
 #     ...
 # };
 our $tilelist;

 # In the current version we keep things simple, the tiles have to be
 # selected either by the command line options --link, --lat, --lon,
 # and --zoom or read from the file as given by --loadtilelist.  In a
 # future version, it might be possible to combine both ways.
 if ($opt{loadtilelist}) {
    $tilelist = LoadFile($opt{loadtilelist});
 }
 else {
    $tilelist = selecttilescmdline;
 }

 our $baseurl = $opt{baseurl};
 our $destdir = $opt{destdir};

 if ($opt{dumptilelist}) {
    DumpFile($opt{dumptilelist}, $tilelist);
 }
 else {
    downloadtiles($tilelist);
 }



 # Select tiles from command line options
 sub selecttilescmdline
 {
    if ($opt{link}) {
 	die "Invalid link: $opt{link}\n"
 	    unless $opt{link} =~ /^http:\/\/.*\/\?lat=(-?\d+(?:\.\d+)?)\&lon=(-?\d+(?:\.\d+)?)\&zoom=(\d+)/;
 	my $lat = $1;
 	my $lon = $2;
 	my $zoom = $3;
 	my $offs = $linkrgoffs / 2**$zoom;

 	# Note that ($lat - $offs, $lat + $offs) or
 	# ($lon - $offs, $lon + $offs) may get out of the acceptable
 	# range of coordinates.  This will eventually get corrected by
 	# checklatrange or checklonrange later on.

 	$opt{latitude} = [ $lat - $offs, $lat + $offs ]
 	    unless defined($opt{latitude});
 	$opt{longitude} = [ $lon - $offs, $lon + $offs ]
 	    unless defined($opt{longitude});
 	$opt{zoom} = $zoom
 	    unless defined($opt{zoom});
    }

    my ($latmin, $latmax) = checklatrange(parserealopt("latitude"));
    my ($lonmin, $lonmax) = checklonrange(parserealopt("longitude"));
    my ($zoommin, $zoommax) = parseintopt("zoom");

    my $tl = {};

    for my $zoom ($zoommin..$zoommax) {

 	my $txmin = lon2tilex($lonmin, $zoom);
 	my $txmax = lon2tilex($lonmax, $zoom);
 	# Note that y=0 is near lat=+85.0511 and y=max is near
 	# lat=-85.0511, so lat2tiley is monotonically decreasing.
 	my $tymin = lat2tiley($latmax, $zoom);
 	my $tymax = lat2tiley($latmin, $zoom);

 	my $ntx = $txmax - $txmin + 1;
 	my $nty = $tymax - $tymin + 1;
 	printf "Schedule %d (%d x %d) tiles for zoom level %d for download ...\n",
 	       $ntx*$nty, $ntx, $nty, $zoom
 	    unless $opt{quiet};
 	$tl->{$zoom} = [];    

 	for my $tx ($txmin..$txmax) {
 	    for my $ty ($tymin..$tymax) {
 		push @{$tl->{$zoom}}, 
 		    { xyz => [ $tx, $ty, $zoom ] };
 	    }
 	}
    }

    return $tl;
 }


 sub downloadtiles
 {
    my $tiles = shift;

    my $lwpua = LWP::UserAgent->new;
    $lwpua->env_proxy;

    for my $zoom (sort {$a <=> $b} keys %$tiles) {

 	printf "Download %d tiles for zoom level %d ...\n",
 	       scalar(@{$tiles->{$zoom}}), $zoom
 	    unless $opt{quiet};

 	for my $t (@{$tiles->{$zoom}}) {
 	    downloadtile($lwpua, @{$t->{xyz}});
 	}
    }
 }


 sub parserealopt
 {
    my ($optname) = @_;

    die "$optname must be specified in the command line.\n"
 	unless defined($opt{$optname});

    if (ref($opt{$optname})) {
 	return @{$opt{$optname}};
    }
    else {
 	die "Invalid $optname: $opt{$optname}\n"
 	    unless $opt{$optname} =~ /^(-?\d+(?:\.\d+)?)(?::(-?\d+(?:\.\d+)?))?$/;
 	my ($min, $max) = ($1, $2);
 	$max = $min unless defined($max);

 	return ($min, $max);
    }
 }


 sub parseintopt
 {
    my ($optname) = @_;

    die "$optname must be specified in the command line.\n"
 	unless defined($opt{$optname});

    if (ref($opt{$optname})) {
 	return @{$opt{$optname}};
    }
    else {
 	die "Invalid $optname: $opt{$optname}\n"
 	    unless $opt{$optname} =~ /^(\d+)(?::(\d+))?$/;
 	my ($min, $max) = ($1, $2);
 	$max = $min unless defined($max);

 	return ($min, $max);
    }
 }


 sub downloadtile
 {
    my ($lwpua, $tilex, $tiley, $zoom) = @_;
    my $path = tile2path($tilex, $tiley, $zoom);
    my $url = "$baseurl/$path";
    my @pathcomp = split /\//, $path;
    my $fname = File::Spec->catfile($destdir, @pathcomp);
    
 	
    mkpath(dirname($fname));
    #my $res = $lwpua->get($url, ':content_file' => $fname);
    
    my $res = $lwpua->get($url);
    die $res->status_line
 	unless $res->is_success;
 	
 	#ikc
    my $image = encode_base64($res->content);
 	
 	$db->do("INSERT INTO tiles VALUES ( 'CloudMade', $tilex,$tiley,$zoom,null, 'data:image/png;base64,$image' )");

 	#
 	
 }






 __END__
 =head1 NAME

 downloadosmtiles.pl - Download map tiles from OpenStreetMap

 =head1 SYNOPSIS

  downloadosmtiles.pl --lat=49.5611:49.6282 --lon=10.951:11.0574 --zoom=13:14
  downloadosmtiles.pl --link='http://www.openstreetmap.org/?lat=-23.5872&lon=-46.6508&zoom=12&layers=B000FTF'
  downloadosmtiles.pl --loadtilelist=filename

 =head1 DESCRIPTION

 This script downloads all map tiles from an OpenStreetMap tile server
 for some geographic region in a range of zoom levels.  The PNG images
 of the tiles are stored in a directory tree that mirrors the paths
 from the server.

 A bounding box of geographic coordinates and a range of zoom levels
 must be selected by command line options.

 =head1 COMMAND LINE OPTIONS

 Command line options may be abbreviated as long as they remain
 unambiguous.

 At least either C<--latitude>, C<--longitude>, and C<--zoom> or
 C<--link> must be specified.

 =head2 C<--latitude=latmin[:latmax]>

 Selects the latitude of the bounding box of coordinates to download.
 May be one single real value or two real values separated by a colon
 in the range C<-85.0511..85.0511>.  If given only one value, just the
 tile (or row of tiles) at this latitude will be downloaded.

 Default: none

 =head2 C<--longitude=lonmin[:lonmax]>

 Selects the longitude of the bounding box of coordinates to download.
 May be one single real value or two real values separated by a colon
 in the range C<-180.0..180.0>.  If given only one value, just the tile
 (or column of tiles) at this longitude will be downloaded.

 Default: none

 =head2 C<--zoom=zoommin[:zoommax]>

 Selects the range of zoom levels to download the map tiles for.  May
 be one single integer value or two integer values separated by a
 colon.  OpenStreetMap supports zoom levels in the range C<0..18>.
 (This depends on the base URL and is not enforced by this script.)

 Note that the number of tiles to download grows by a factor of up to
 four with each zoom level.

 Default: none

 =head2 C<--link=url>

 An URL selecting C<--latitude>, C<--longitude>, and C<--zoom> in one
 argument.  The idea is to select the current view of OSM's slippy map
 by its permalink.

 The argument to C<--link> must be an URL containing the HTTP options
 C<?lat=s&lon=s&zoom=s>.  (Actually, the base URL will be ignored.)
 The script chooses a box around the latitude and longitude options.
 The size of the box depends on the zoom option.

 If combined with C<--latitude>, C<--longitude>, or C<--zoom>, these
 explicitly specified values override the implicitly specified values
 from C<--link>.

 Default: none

 =head2 C<--baseurl=url>

 The base URL of the server to download the tiles from.

 Default: L<http://tile.openstreetmap.org>
 (This is the base URL for the Mapnik tiles.)

 =head2 C<--destdir=dir>

 The directory where the tiles will be stored.  The PNG files will be
 stored as C<dir/zoom/x/y.png>.

 Default: The current working directory.

 =head2 C<--quiet>

 Do not write any diagnostic messages.  Only fatal errors will be
 reported.

 =head2 C<--dumptilelist=filename>

 Do not download any tiles at all, but write a list of tiles as
 selected by other command line options to the file named C<filename>.
 See L</TILE LISTS> below.

 =head2 C<--loadtilelist=filename>

 Read a list of tiles to download from the file C<filename>.  See
 L</TILE LISTS> below.

 =head1 EXAMPLE

 Select the region of interest in OSM's slippy map and follow the
 permalink in the lower left of the window.  Lets assume this permalink
 to be
 L<http://www.openstreetmap.org/?lat=49.5782&lon=11.0076&zoom=12&layers=B000FTF>.
 Then

  downloadosmtiles.pl --link='http://www.openstreetmap.org/?lat=49.5782&lon=11.0076&zoom=12&layers=B000FTF' --zoom=5:18

 will download all tiles from zoom level 5 to 18 for this region.

 =head1 TILE LISTS

 A list of tiles may be stored to and retrieved from external files
 using the C<--dumptilelist> and C<--loadtilelist> command line
 options.  A set of tiles may be selected using the command line
 options C<--latitude>, C<--longitude>, C<--zoom>, and C<--link> and
 written to a file specified with C<--dumptilelist>.  This list may be
 read at a later date using the C<--loadtilelist> option.

 This may be useful to postpone the download of the tiles, to edit the
 list of tiles, or to use some external tool to generate this list.

 The tile lists are read and written in L<YAML> format.  Please note
 that this is an experimental feature in the current version.  The file
 format is not considered stable yet.  There is no guarantee that a
 list of tiles generated by one version of this script may be read in
 by a future version.

 =head1 ENVIRONMENT

 =over

 =item http_proxy

 =item ftp_proxy

 =item xxx_proxy

 =item no_proxy

 These environment variables can be set to enable communication through
 a proxy server.  This is implemented by L<LWP::UserAgent>.

 =back

 =head1 BUGS

 =over

 =item *

 Ranges in the command line options must always be increasing.  While
 this is considered a feature for C<--latitude> and C<--zoom>, it means
 that it is impossible for a range in the C<--longitude> argument to
 cross the 180 degree line.  A command line option like
 C<--longitude=179.5:-179.5> will not work as one should expect.

 =item *

 The bounding box selected by the C<--link> command line option does
 not always correspond to the current view in the slippy map.  The
 problem is that the permalink from the slippy map only contains one
 position and not the bounds of the current view.  The actual view of
 the slippy map depends on many factors, including the size of the
 browser window.  Thus, there is not much that can be done about this
 issue.

 =back

 =head1 SEE ALSO

 L<http://wiki.openstreetmap.org/wiki/Slippy_Map>

 =head1 AUTHOR

 Rolf Krahl E<lt>[email protected]E<gt>

 =head1 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.

 =cut
	#! /usr/bin/perl


	# 2011
	# added a few mods to script to allow to be pushed into sqlite
	# coomsie at gmail.com

	use 5.006001;
	use strict;
	use warnings;
	use Geo::OSM::Tiles qw( :all );
	use LWP::UserAgent;
	use YAML qw( DumpFile LoadFile );
	use File::Path;
	use File::Basename;
	use File::Spec;
	use Cwd qw(cwd);
	use Getopt::Long;

	# IKC addtions
	use DBI;
	use MIME::Base64;

	my $db = DBI->connect("dbi:SQLite:dbname=0000000000000001.db",
	"","");

	my $cursor;
	my @rec;

	#$db->do("DROP TABLE IF EXISTS 'tiles';");
	$db->do("CREATE TABLE IF NOT EXISTS tiles (provider TEXT, x INT, y INT, z INT, timestamp REAL, data BLOB);");
	#$db->do("DROP TABLE IF EXISTS '__WebKitDatabaseInfoTable__';");
	$db->do("CREATE TABLE IF NOT EXISTS __WebKitDatabaseInfoTable__ (key TEXT NOT NULL ON CONFLICT FAIL UNIQUE ON CONFLICT REPLACE,value TEXT NOT NULL ON CONFLICT FAIL);");
	$db->do("INSERT INTO '__WebKitDatabaseInfoTable__' VALUES('WebKitDatabaseVersionKey','1.0');");

	#$db->do("DROP TABLE IF EXISTS 'ini';");
	$db->do("CREATE TABLE IF NOT EXISTS ini (key TEXT, value TEXT);");
	$db->do("INSERT INTO 'ini' VALUES('lat','0.0');");
	$db->do("INSERT INTO 'ini' VALUES('lon','0.0');");
	$db->do("INSERT INTO 'ini' VALUES('zoom','0.0');");

	#

	our $linkrgoffs = 350.0;

	our $usage = qq{Usage:
	$0 --latitude=d[:d] --longitude=d[:d] --zoom=z[:z] [--quiet] [--baseurl=url] [--destdir=dir] [--dumptilelist=filename]
	$0 --link=url [--latitude=d[:d]] [--longitude=d[:d]] [--zoom=z[:z]] [--quiet] [--baseurl=url] [--destdir=dir] [--dumptilelist=filename]
	$0 --loadtilelist=filename
	};

	our %opt = (
	latitude => undef,
	longitude => undef,
	zoom => undef,
	link => undef,
	quiet => undef,
	baseurl => "http://tile.openstreetmap.org",
	destdir => cwd,
	dumptilelist => undef,
	loadtilelist => undef,
	);

	die "$usage\n"
	unless GetOptions(\%opt,
	"latitude=s", "longitude=s", "zoom=s", "link=s",
	"quiet", "baseurl=s", "destdir=s",
	"dumptilelist=s", "loadtilelist=s") &&
	@ARGV == 0;

	sub selecttilescmdline;
	sub downloadtiles;
	sub parserealopt;
	sub parseintopt;
	sub downloadtile;


	# List of tiles scheduled for download.
	# Format:
	# $tilelist = {
	# zoomlevel => [
	# {
	# xyz => [ tx, ty, tz ],
	# },
	# {
	# xyz => [ tx, ty, tz ],
	# },
	# ...
	# ],
	# zoomlevel => [
	# {
	# xyz => [ tx, ty, tz ],
	# },
	# {
	# xyz => [ tx, ty, tz ],
	# },
	# ...
	# ],
	# ...
	# };
	our $tilelist;

	# In the current version we keep things simple, the tiles have to be
	# selected either by the command line options --link, --lat, --lon,
	# and --zoom or read from the file as given by --loadtilelist. In a
	# future version, it might be possible to combine both ways.
	if ($opt{loadtilelist}) {
	$tilelist = LoadFile($opt{loadtilelist});
	}
	else {
	$tilelist = selecttilescmdline;
	}

	our $baseurl = $opt{baseurl};
	our $destdir = $opt{destdir};

	if ($opt{dumptilelist}) {
	DumpFile($opt{dumptilelist}, $tilelist);
	}
	else {
	downloadtiles($tilelist);
	}



	# Select tiles from command line options
	sub selecttilescmdline
	{
	if ($opt{link}) {
	die "Invalid link: $opt{link}\n"
	unless $opt{link} =~ /^http:\/\/.*\/\?lat=(-?\d+(?:\.\d+)?)\&lon=(-?\d+(?:\.\d+)?)\&zoom=(\d+)/;
	my $lat = $1;
	my $lon = $2;
	my $zoom = $3;
	my $offs = $linkrgoffs / 2**$zoom;

	# Note that ($lat - $offs, $lat + $offs) or
	# ($lon - $offs, $lon + $offs) may get out of the acceptable
	# range of coordinates. This will eventually get corrected by
	# checklatrange or checklonrange later on.

	$opt{latitude} = [ $lat - $offs, $lat + $offs ]
	unless defined($opt{latitude});
	$opt{longitude} = [ $lon - $offs, $lon + $offs ]
	unless defined($opt{longitude});
	$opt{zoom} = $zoom
	unless defined($opt{zoom});
	}

	my ($latmin, $latmax) = checklatrange(parserealopt("latitude"));
	my ($lonmin, $lonmax) = checklonrange(parserealopt("longitude"));
	my ($zoommin, $zoommax) = parseintopt("zoom");

	my $tl = {};

	for my $zoom ($zoommin..$zoommax) {

	my $txmin = lon2tilex($lonmin, $zoom);
	my $txmax = lon2tilex($lonmax, $zoom);
	# Note that y=0 is near lat=+85.0511 and y=max is near
	# lat=-85.0511, so lat2tiley is monotonically decreasing.
	my $tymin = lat2tiley($latmax, $zoom);
	my $tymax = lat2tiley($latmin, $zoom);

	my $ntx = $txmax - $txmin + 1;
	my $nty = $tymax - $tymin + 1;
	printf "Schedule %d (%d x %d) tiles for zoom level %d for download ...\n",
	$ntx*$nty, $ntx, $nty, $zoom
	unless $opt{quiet};
	$tl->{$zoom} = [];

	for my $tx ($txmin..$txmax) {
	for my $ty ($tymin..$tymax) {
	push @{$tl->{$zoom}},
	{ xyz => [ $tx, $ty, $zoom ] };
	}
	}
	}

	return $tl;
	}


	sub downloadtiles
	{
	my $tiles = shift;

	my $lwpua = LWP::UserAgent->new;
	$lwpua->env_proxy;

	for my $zoom (sort {$a <=> $b} keys %$tiles) {

	printf "Download %d tiles for zoom level %d ...\n",
	scalar(@{$tiles->{$zoom}}), $zoom
	unless $opt{quiet};

	for my $t (@{$tiles->{$zoom}}) {
	downloadtile($lwpua, @{$t->{xyz}});
	}
	}
	}


	sub parserealopt
	{
	my ($optname) = @_;

	die "$optname must be specified in the command line.\n"
	unless defined($opt{$optname});

	if (ref($opt{$optname})) {
	return @{$opt{$optname}};
	}
	else {
	die "Invalid $optname: $opt{$optname}\n"
	unless $opt{$optname} =~ /^(-?\d+(?:\.\d+)?)(?::(-?\d+(?:\.\d+)?))?$/;
	my ($min, $max) = ($1, $2);
	$max = $min unless defined($max);

	return ($min, $max);
	}
	}


	sub parseintopt
	{
	my ($optname) = @_;

	die "$optname must be specified in the command line.\n"
	unless defined($opt{$optname});

	if (ref($opt{$optname})) {
	return @{$opt{$optname}};
	}
	else {
	die "Invalid $optname: $opt{$optname}\n"
	unless $opt{$optname} =~ /^(\d+)(?::(\d+))?$/;
	my ($min, $max) = ($1, $2);
	$max = $min unless defined($max);

	return ($min, $max);
	}
	}


	sub downloadtile
	{
	my ($lwpua, $tilex, $tiley, $zoom) = @_;
	my $path = tile2path($tilex, $tiley, $zoom);
	my $url = "$baseurl/$path";
	my @pathcomp = split /\//, $path;
	my $fname = File::Spec->catfile($destdir, @pathcomp);


	mkpath(dirname($fname));
	#my $res = $lwpua->get($url, ':content_file' => $fname);

	my $res = $lwpua->get($url);
	die $res->status_line
	unless $res->is_success;

	#ikc
	my $image = encode_base64($res->content);

	$db->do("INSERT INTO tiles VALUES ( 'CloudMade', $tilex,$tiley,$zoom,null, 'data:image/png;base64,$image' )");

	#

	}






	__END__
	=head1 NAME

	downloadosmtiles.pl - Download map tiles from OpenStreetMap

	=head1 SYNOPSIS

	downloadosmtiles.pl --lat=49.5611:49.6282 --lon=10.951:11.0574 --zoom=13:14
	downloadosmtiles.pl --link='http://www.openstreetmap.org/?lat=-23.5872&lon=-46.6508&zoom=12&layers=B000FTF'
	downloadosmtiles.pl --loadtilelist=filename

	=head1 DESCRIPTION

	This script downloads all map tiles from an OpenStreetMap tile server
	for some geographic region in a range of zoom levels. The PNG images
	of the tiles are stored in a directory tree that mirrors the paths
	from the server.

	A bounding box of geographic coordinates and a range of zoom levels
	must be selected by command line options.

	=head1 COMMAND LINE OPTIONS

	Command line options may be abbreviated as long as they remain
	unambiguous.

	At least either C<--latitude>, C<--longitude>, and C<--zoom> or
	C<--link> must be specified.

	=head2 C<--latitude=latmin[:latmax]>

	Selects the latitude of the bounding box of coordinates to download.
	May be one single real value or two real values separated by a colon
	in the range C<-85.0511..85.0511>. If given only one value, just the
	tile (or row of tiles) at this latitude will be downloaded.

	Default: none

	=head2 C<--longitude=lonmin[:lonmax]>

	Selects the longitude of the bounding box of coordinates to download.
	May be one single real value or two real values separated by a colon
	in the range C<-180.0..180.0>. If given only one value, just the tile
	(or column of tiles) at this longitude will be downloaded.

	Default: none

	=head2 C<--zoom=zoommin[:zoommax]>

	Selects the range of zoom levels to download the map tiles for. May
	be one single integer value or two integer values separated by a
	colon. OpenStreetMap supports zoom levels in the range C<0..18>.
	(This depends on the base URL and is not enforced by this script.)

	Note that the number of tiles to download grows by a factor of up to
	four with each zoom level.

	Default: none

	=head2 C<--link=url>

	An URL selecting C<--latitude>, C<--longitude>, and C<--zoom> in one
	argument. The idea is to select the current view of OSM's slippy map
	by its permalink.

	The argument to C<--link> must be an URL containing the HTTP options
	C<?lat=s&lon=s&zoom=s>. (Actually, the base URL will be ignored.)
	The script chooses a box around the latitude and longitude options.
	The size of the box depends on the zoom option.

	If combined with C<--latitude>, C<--longitude>, or C<--zoom>, these
	explicitly specified values override the implicitly specified values
	from C<--link>.

	Default: none

	=head2 C<--baseurl=url>

	The base URL of the server to download the tiles from.

	Default: L<http://tile.openstreetmap.org>
	(This is the base URL for the Mapnik tiles.)

	=head2 C<--destdir=dir>

	The directory where the tiles will be stored. The PNG files will be
	stored as C<dir/zoom/x/y.png>.

	Default: The current working directory.

	=head2 C<--quiet>

	Do not write any diagnostic messages. Only fatal errors will be
	reported.

	=head2 C<--dumptilelist=filename>

	Do not download any tiles at all, but write a list of tiles as
	selected by other command line options to the file named C<filename>.
	See L</TILE LISTS> below.

	=head2 C<--loadtilelist=filename>

	Read a list of tiles to download from the file C<filename>. See
	L</TILE LISTS> below.

	=head1 EXAMPLE

	Select the region of interest in OSM's slippy map and follow the
	permalink in the lower left of the window. Lets assume this permalink
	to be
	L<http://www.openstreetmap.org/?lat=49.5782&lon=11.0076&zoom=12&layers=B000FTF>.
	Then

	downloadosmtiles.pl --link='http://www.openstreetmap.org/?lat=49.5782&lon=11.0076&zoom=12&layers=B000FTF' --zoom=5:18

	will download all tiles from zoom level 5 to 18 for this region.

	=head1 TILE LISTS

	A list of tiles may be stored to and retrieved from external files
	using the C<--dumptilelist> and C<--loadtilelist> command line
	options. A set of tiles may be selected using the command line
	options C<--latitude>, C<--longitude>, C<--zoom>, and C<--link> and
	written to a file specified with C<--dumptilelist>. This list may be
	read at a later date using the C<--loadtilelist> option.

	This may be useful to postpone the download of the tiles, to edit the
	list of tiles, or to use some external tool to generate this list.

	The tile lists are read and written in L<YAML> format. Please note
	that this is an experimental feature in the current version. The file
	format is not considered stable yet. There is no guarantee that a
	list of tiles generated by one version of this script may be read in
	by a future version.

	=head1 ENVIRONMENT

	=over

	=item http_proxy

	=item ftp_proxy

	=item xxx_proxy

	=item no_proxy

	These environment variables can be set to enable communication through
	a proxy server. This is implemented by L<LWP::UserAgent>.

	=back

	=head1 BUGS

	=over

	=item *

	Ranges in the command line options must always be increasing. While
	this is considered a feature for C<--latitude> and C<--zoom>, it means
	that it is impossible for a range in the C<--longitude> argument to
	cross the 180 degree line. A command line option like
	C<--longitude=179.5:-179.5> will not work as one should expect.

	=item *

	The bounding box selected by the C<--link> command line option does
	not always correspond to the current view in the slippy map. The
	problem is that the permalink from the slippy map only contains one
	position and not the bounds of the current view. The actual view of
	the slippy map depends on many factors, including the size of the
	browser window. Thus, there is not much that can be done about this
	issue.

	=back

	=head1 SEE ALSO

	L<http://wiki.openstreetmap.org/wiki/Slippy_Map>

	=head1 AUTHOR

	Rolf Krahl E<lt>[email protected]E<gt>

	=head1 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.

	=cut