=head1 NAME

Geo::EncodedPolyline - Encoding and decoding of encoded polylines

=head1 SYNOPSIS

  use Geo::EncodedPolyline;
  warn Geo::EncodedPolyline->encode ([[$lat, $lon], ...], 1e5);
  warn Dumper Geo::EncodedPolyline->decode ($input, 2, 1e5);

=head1 DESCRIPTION

The C<Geo::EncodedPolyline> module implements the Encoded Polyline
Algorithm as used by Google Maps and other map applications.

=head1 METHODS

Following methods are available:

=over 4

=item $encoded = Geo::EncodedPolyline->encode ($decoded, $f)

Encodes the list of items and returns the result string.

The first argument must be an array reference of array references,
where the inner arrays must contain same numbers of items.  Each item
of the inner arrays must be numbers.

To encode a list of pairs of latitude and longitude, as used by Google
Maps, specify the list of latitude and longitude (both in decimal), as
an array reference of array references, and the factor value C<1e5>,
as the arguments.

=item $decoded = Geo::EncodedPolyline->decode ($encoded, $n, $f)

Decodes the encoded polyline string and returns the result list.

The second argument represents the number of the items in each pair.

To decode a polyline encoded list of pairs of latitude and longitude,
as used by Google Maps, specify the encoded string, the number of
items in each pair C<2> (i.e. latitude and longitude), and the factor
value C<1e5>.

The method returns an array reference of array references, where inner
arrays represent the pairs in the list.  When the input is broken, the
returned list might be incomplete.

=back

Please note that the factor value I<$f> affects the precision of
encoded numbers, i.e. whether the original value can be obtained by
encoding a number and then decoding its result.  When C<$n * $f> is an
integer, the exact number C<$n> can be obtained.

=head1 SPECIFICATION

Encoded Polyline Algorithm Format
<https://developers.google.com/maps/documentation/utilities/polylinealgorithm>.

=head1 SEE ALSO

SuikaWiki: Encoded Polyline
<https://wiki.suikawiki.org/n/Encoded%20Polyline>.

=head1 AUTHOR

Wakaba <wakaba@suikawiki.org>.

=head1 LICENSE

Copyright 2016-2018 Wakaba <wakaba@suikawiki.org>.

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

=cut