NAME
    WebService::GoogleMaps - Automated interface to Google Maps

SYNOPSIS
        use WebService::GoogleMaps;

        # Set up a new object with a viewport of 640 x 480 pixels
        my $gmap = WebService::GoogleMaps->new( 640, 480 );

        # Specify a location to view
        $gmap->set(
            latitude   => 40.750275,
            longitude  => -73.993034,
            zoom_level => 4,          # valid values are 0..14, lower value is more zoomed
            cache_dir  => "/tmp",     # optional, but recommended!  Helps speed up future requests
            pan_x      => 0,          # move viewport to the east  (+) or west  (-) a number of pixels
            pan_y      => 0,          # move viewport to the south (+) or north (-) a number of pixels
        );

        # create a GD object containing our bitmapped map object
        my $gd = $gmap->generate_gd();

        # or simply
        # my $gd = $gmap->generate_gd(40.750275, -73.993034, 4);  # latitude, longitude, zoom_level

        my $error = $gmap->error();
        $error && print "Error: $error\n";
    
        open (FH, ">", "mymap.png");
        binmode FH;
        print FH $gd->png;
        close(FH);

DESCRIPTION
    WebService::GoogleMaps provides an automated interface to Google Maps
    <http://maps.google.com/>, which provides free street maps of locations
    in the USA and Canada. This module allows you to specify an image size,
    latitude, longitude, and zoom level and returns a GD object containing a
    street level map.

METHODS
  new()
    The constructor. You can pass it an image width and height in pixels, or
    nothing to let it default to 640 x 480 pixels. Or instead, pass it a
    list of initial options and values.

        # set up our object to create a 320 x 240 pixel image
        my $gmap = WebService::GoogleMaps->new( 800, 600 );

        # use the default 640 x 480 image size
        my $gmap = WebService::GoogleMaps->new();

        # specify several options and values
        my $gmap = WebService::GoogleMaps->new(
            width      => 800,
            height     => 600,
            latitude   => 40.750275,
            longitude  => -73.993034,
            zoom_level => 3,
            agent      => "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)",  # optional, default is a Firefox agent.
            cache_dir  => "/tmp",     # optional, but helps speed up future requests
            pan_x      => 100,        # move viewport 100 pixels east
            pan_y      => 100,        # move viewport 100 pixels south
        );

  set()
    Use this method to add or change any of the map options after you have
    created the object.

        # Create our object, using the default 640 x 480 image size
        my $gmap = WebService::GoogleMaps->new();
    
        # Set width, height, latitude, longitude, zoom level and cache directory when requesting map data
        $gmap->set(
            width      => 800,
            height     => 600,
            latitude   => 40.750275,
            longitude  => -73.993034,
            zoom_level => 9,
            cache_dir  => "/tmp",
        );

  get()
    Use this method to retrieve the value of any of the current options

        # Find out what the current zoom level is set to
        my $zoom_level = $gmap->get("zoom_level");

  error()
    Use this to retrieve any errors generated by this module.

  generate_gd()
    This performs the retrieval of the image from Google Maps. If the images
    are not found in the cache, (assuming you have specified a directory to
    use for the cache), this may take a little extra time to complete.

    It will return a GD object, which you may then use as you please. It is
    useful to save it to a file.

    If there is a problem creating the image, an error message will be set.
    You may retrieve this error message at $gmap->error()

        # create a GD object containing our bitmapped map object
        my $gd = $gmap->generate_gd();

        if ( $gmap->error() ) {
            print "Error: ".$gmap->error()."\n";
        }
        else {
            open (FH, ">", "mymap.png");
            binmode FH;
            print FH $gd->png;
            close(FH);
        }

  generate_html()
    Not available in this version. The plan is to have this return HTML code
    that will reference images on the Google Maps server to render the map
    image.

TODO
    * Improve caching method. Maybe use subdirectories to separate cached
    images into geographic areas?
    * Put a water tile in places ourside the available data ranges?
    * Develop the generate_html method

AUTHOR
    Karl Lohner, <karllohner+googlemaps@gmail.com>

BUGS
    Please report any bugs or feature requests to
    <karllohner+googlemaps@gmail.com>.

    Really, I would like to know how you are using this module and what you
    would like to see to make it better.

ACKNOWLEDGEMENTS
    Thanks to Joel Webber and his blog article at
    http://jgwebber.blogspot.com/2005/02/mapping-google.html as well as to
    the many people who added comments there, particularly the anonymous
    comments that detailed the algorithm used to map latitude/longitude to
    specific tiles.

COPYRIGHT AND LICENSE
    Copyright 2005 by Karl Lohner, All Rights Reserved.

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