This issue was updated by revision r735.

Made this a global maps option.

This issue was updated by revision r736.

Forgot to add the MarkerClusterer javascript! Now it should work.

Hey Dylan,

Testing 1.4alpha8. Performance improvement of V3 maps is noticeable! 
Can't seem to get markerClusterer working? Does it require activation via 
custom.js?

Cheers
Ben

[deleted comment]

There are a number of features that are still v2-only, including clustering. 
Ideally I'd like to implement some kind of server-side clustering that would 
work for all APIs moving forward, but I consider that a separate feature.

I just found a tricky workaround to make cluster work in 1.4alpha.
In geo-mashup-custom.php add this code to load the library (placed in the 
custom plugin folder):

function my_script_check() {    
  global $geo_mashup_options;
  $map_api = $geo_mashup_options->get( 'overall', 'map_api' );
  if ('googlev3' == $map_api) {
      $basename = plugin_basename( __FILE__ );
      $dir_name = substr( $basename, 0, strpos( $basename, '/' ) );      
      wp_enqueue_script( 'google-maps-3-cluster-marker', '/wp-content/plugins/'.$dir_name.'/markerclusterer_packed.js', array( 'google-maps-3'));
    }  
} 
add_action( 'wp_print_scripts', 'my_script_check' );

then in custom.js:

// Override addMarkers to save google.maps.Markers
GeoMashup.propietary_markers = [];
GeoMashup.addMarkers = function( markers ) {
    this.forEach( markers, function( i, marker ) {
      this.map.addMarker( marker );
      GeoMashup.propietary_markers.push(marker.proprietary_marker);
    } );
};

GeoMashup.addAction( 'loadedMap', function ( opts, map )
{
  var markerCluster = new MarkerClusterer(map.maps[map.api], GeoMashup.propietary_markers);  
} ); 

@vcausarano: Nice work! Based on this, maybe I can preserve clustering using 
MarkerClusterer in GM 1.4. 

@dylan
Thanks! It means a lot as it's the first time I play with javascript.
The drawbacks using client side cluster is that MarkerClusterer seems to be 
very slow under IE and that it slow down the markers render after a zoom even 
when > maxZoom.

hmm it seems that markercluster only works for visible markers.
so making it work with hide-show categories requires a lot of coding.

Bummer - I bet that's an issue with v2 also, I'll have to test it. 

Are you interesting in working on Geo Mashup? If so, send me an email - Google 
code requires an email address for me to add you to the project. You can allow 
access to your email (as I have) in your Google code profile too.

Related: http://code.google.com/p/wordpress-geo-mashup/issues/detail?id=407

It's not looking like I'll solve this for Geo Mashup 1.4 - hopefully soon after.

I' m not sure if it is optimal but that would fix the hide-show category 
problem.

GeoMashup.recluster = function() {
    var point;
    var markers = [];

    for (point in this.locations) {
        if ( this.locations.hasOwnProperty( point ) && this.locations[point].marker ) {
            if( this.isMarkerOn( this.locations[point].marker )) {
                markers.push(this.locations[point].marker.proprietary_marker);
            }
        }
    }

    markerCluster.clearMarkers();
    markerCluster.addMarkers(markers);
};

This issue was updated by revision e5209d2de4ff.

Got MarkerClusterer working! There has been lots of interest in this but
no financial support - donations would help to test, polish, and release it.

https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=11045324

This issue was updated by revision 4876cd27ad83.

Got MarkerClusterer working! There has been lots of interest in this but
no financial support - donations would help to test, polish, and release it.

https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=11045324

I just sent you a donation. Thanks for the great plugin and I look forward to 
this new release. Once it gets released I would love to send more.

Wade
http://5starcampgrounds.com

[deleted comment]

This issue was updated by revision 4467b5b6096b.

Got it working in IE8 using a modernizr test. Beating my chest, arrrrghghghg!

I've put up a beta release, test it out!

https://code.google.com/p/wordpress-geo-mashup/downloads/detail?name=geo-mashup-
1.6.0-beta1.zip

Just testing not had time before now the clustering seems to work great thank 
you and yep definitely needs a donation many thanks Dylan!