Working Leaflet.markercluster-src.js for 1.0 beta 1

/*
 Leaflet.markercluster, Provides Beautiful Animated Marker Clustering functionality for Leaflet, a JS library for interactive maps.
 https://github.com/Leaflet/Leaflet.markercluster
 (c) 2012-2013, Dave Leaver, smartrak
*/
(function (window, document, undefined) {/*
 * L.MarkerClusterGroup extends L.FeatureGroup by clustering the markers contained within
 */

L.MarkerClusterGroup = L.FeatureGroup.extend({

    options: {
        maxClusterRadius: 80, //A cluster will cover at most this many pixels from its center
        iconCreateFunction: null,

        spiderfyOnMaxZoom: true,
        showCoverageOnHover: true,
        zoomToBoundsOnClick: true,
        singleMarkerMode: false,

        disableClusteringAtZoom: null,

        // Setting this to false prevents the removal of any clusters outside of the viewpoint, which
        // is the default behaviour for performance reasons.
        removeOutsideVisibleBounds: true,

        //Whether to animate adding markers after adding the MarkerClusterGroup to the map
        // If you are adding individual markers set to true, if adding bulk markers leave false for massive performance gains.
        animateAddingMarkers: false,

        //Increase to increase the distance away that spiderfied markers appear from the center
        spiderfyDistanceMultiplier: 1,

        // When bulk adding layers, adds markers in chunks. Means addLayers may not add all the layers in the call, others will be loaded during setTimeouts
        chunkedLoading: false,
        chunkInterval: 200, // process markers for a maximum of ~ n milliseconds (then trigger the chunkProgress callback)
        chunkDelay: 50, // at the end of each interval, give n milliseconds back to system/browser
        chunkProgress: null, // progress callback: function(processed, total, elapsed) (e.g. for a progress indicator)

        //Options to pass to the L.Polygon constructor
        polygonOptions: {}
    },

    initialize: function (options) {
        L.Util.setOptions(this, options);
        if (!this.options.iconCreateFunction) {
            this.options.iconCreateFunction = this._defaultIconCreateFunction;
        }

        this._featureGroup = L.featureGroup();
        this._featureGroup.addEventParent(this);

        this._nonPointGroup = L.featureGroup();
        this._nonPointGroup.addEventParent(this);

        this._inZoomAnimation = 0;
        this._needsClustering = [];
        this._needsRemoving = []; //Markers removed while we aren't on the map need to be kept track of
        //The bounds of the currently shown area (from _getExpandedVisibleBounds) Updated on zoom/move
        this._currentShownBounds = null;

        this._queue = [];
    },

    addLayer: function (layer) {

        if (layer instanceof L.LayerGroup) {
            var array = [];
            for (var i in layer._layers) {
                array.push(layer._layers[i]);
            }
            return this.addLayers(array);
        }

        //Don't cluster non point data
        if (!layer.getLatLng) {
            this._nonPointGroup.addLayer(layer);
            return this;
        }

        if (!this._map) {
            this._needsClustering.push(layer);
            return this;
        }

        if (this.hasLayer(layer)) {
            return this;
        }


        //If we have already clustered we'll need to add this one to a cluster

        if (this._unspiderfy) {
            this._unspiderfy();
        }

        this._addLayer(layer, this._maxZoom);

        //Work out what is visible
        var visibleLayer = layer,
            currentZoom = this._map.getZoom();
        if (layer.__parent) {
            while (visibleLayer.__parent._zoom >= currentZoom) {
                visibleLayer = visibleLayer.__parent;
            }
        }

        if (this._currentShownBounds.contains(visibleLayer.getLatLng())) {
            if (this.options.animateAddingMarkers) {
                this._animationAddLayer(layer, visibleLayer);
            } else {
                this._animationAddLayerNonAnimated(layer, visibleLayer);
            }
        }
        return this;
    },

    removeLayer: function (layer) {

        if (layer instanceof L.LayerGroup)
        {
            var array = [];
            for (var i in layer._layers) {
                array.push(layer._layers[i]);
            }
            return this.removeLayers(array);
        }

        //Non point layers
        if (!layer.getLatLng) {
            this._nonPointGroup.removeLayer(layer);
            return this;
        }

        if (!this._map) {
            if (!this._arraySplice(this._needsClustering, layer) && this.hasLayer(layer)) {
                this._needsRemoving.push(layer);
            }
            return this;
        }

        if (!layer.__parent) {
            return this;
        }

        if (this._unspiderfy) {
            this._unspiderfy();
            this._unspiderfyLayer(layer);
        }

        //Remove the marker from clusters
        this._removeLayer(layer, true);

        layer.off('move', this._childMarkerMoved, this);

        if (this._featureGroup.hasLayer(layer)) {
            this._featureGroup.removeLayer(layer);
            if (layer.setOpacity) {
                layer.setOpacity(1);
            }
        }

        return this;
    },

    //Takes an array of markers and adds them in bulk
    addLayers: function (layersArray) {
        var fg = this._featureGroup,
            npg = this._nonPointGroup,
            chunked = this.options.chunkedLoading,
            chunkInterval = this.options.chunkInterval,
            chunkProgress = this.options.chunkProgress,
            newMarkers, i, l, m;

        if (this._map) {
            var offset = 0,
                started = (new Date()).getTime();
            var process = L.bind(function () {
                var start = (new Date()).getTime();
                for (; offset < layersArray.length; offset++) {
                    if (chunked && offset % 200 === 0) {
                        // every couple hundred markers, instrument the time elapsed since processing started:
                        var elapsed = (new Date()).getTime() - start;
                        if (elapsed > chunkInterval) {
                            break; // been working too hard, time to take a break :-)
                        }
                    }

                    m = layersArray[offset];

                    //Not point data, can't be clustered
                    if (!m.getLatLng) {
                        npg.addLayer(m);
                        continue;
                    }

                    if (this.hasLayer(m)) {
                        continue;
                    }

                    this._addLayer(m, this._maxZoom);

                    //If we just made a cluster of size 2 then we need to remove the other marker from the map (if it is) or we never will
                    if (m.__parent) {
                        if (m.__parent.getChildCount() === 2) {
                            var markers = m.__parent.getAllChildMarkers(),
                                otherMarker = markers[0] === m ? markers[1] : markers[0];
                            fg.removeLayer(otherMarker);
                        }
                    }
                }

                if (chunkProgress) {
                    // report progress and time elapsed:
                    chunkProgress(offset, layersArray.length, (new Date()).getTime() - started);
                }

                if (offset === layersArray.length) {
                    //Update the icons of all those visible clusters that were affected
                    this._featureGroup.eachLayer(function (c) {
                        if (c instanceof L.MarkerCluster && c._iconNeedsUpdate) {
                            c._updateIcon();
                        }
                    });

                    this._topClusterLevel._recursivelyAddChildrenToMap(null, this._zoom, this._currentShownBounds);
                } else {
                    setTimeout(process, this.options.chunkDelay);
                }
            }, this);

            process();
        } else {
            newMarkers = [];
            for (i = 0, l = layersArray.length; i < l; i++) {
                m = layersArray[i];

                //Not point data, can't be clustered
                if (!m.getLatLng) {
                    npg.addLayer(m);
                    continue;
                }

                if (this.hasLayer(m)) {
                    continue;
                }

                newMarkers.push(m);
            }
            this._needsClustering = this._needsClustering.concat(newMarkers);
        }
        return this;
    },

    //Takes an array of markers and removes them in bulk
    removeLayers: function (layersArray) {
        var i, l, m,
            fg = this._featureGroup,
            npg = this._nonPointGroup;

        if (!this._map) {
            for (i = 0, l = layersArray.length; i < l; i++) {
                m = layersArray[i];
                this._arraySplice(this._needsClustering, m);
                npg.removeLayer(m);
            }
            return this;
        }

        for (i = 0, l = layersArray.length; i < l; i++) {
            m = layersArray[i];

            if (!m.__parent) {
                npg.removeLayer(m);
                continue;
            }

            this._removeLayer(m, true, true);

            if (fg.hasLayer(m)) {
                fg.removeLayer(m);
                if (m.setOpacity) {
                    m.setOpacity(1);
                }
            }
        }

        //Fix up the clusters and markers on the map
        this._topClusterLevel._recursivelyAddChildrenToMap(null, this._zoom, this._currentShownBounds);

        fg.eachLayer(function (c) {
            if (c instanceof L.MarkerCluster) {
                c._updateIcon();
            }
        });

        return this;
    },

    //Removes all layers from the MarkerClusterGroup
    clearLayers: function () {
        //Need our own special implementation as the LayerGroup one doesn't work for us

        //If we aren't on the map (yet), blow away the markers we know of
        if (!this._map) {
            this._needsClustering = [];
            delete this._gridClusters;
            delete this._gridUnclustered;
        }

        if (this._noanimationUnspiderfy) {
            this._noanimationUnspiderfy();
        }

        //Remove all the visible layers
        this._featureGroup.clearLayers();
        this._nonPointGroup.clearLayers();

        this.eachLayer(function (marker) {
            marker.off('move', this._childMarkerMoved, this);
            delete marker.__parent;
        });

        if (this._map) {
            //Reset _topClusterLevel and the DistanceGrids
            this._generateInitialClusters();
        }

        return this;
    },

    //Override FeatureGroup.getBounds as it doesn't work
    getBounds: function () {
        var bounds = new L.LatLngBounds();
        if (this._topClusterLevel) {
            bounds.extend(this._topClusterLevel._bounds);
        } else {
            for (var i = this._needsClustering.length - 1; i >= 0; i--) {
                bounds.extend(this._needsClustering[i].getLatLng());
            }
        }

        bounds.extend(this._nonPointGroup.getBounds());

        return bounds;
    },

    //Overrides LayerGroup.eachLayer
    eachLayer: function (method, context) {
        var markers = this._needsClustering.slice(),
            i;

        if (this._topClusterLevel) {
            this._topClusterLevel.getAllChildMarkers(markers);
        }

        for (i = markers.length - 1; i >= 0; i--) {
            method.call(context, markers[i]);
        }

        this._nonPointGroup.eachLayer(method, context);
    },

    //Overrides LayerGroup.getLayers
    getLayers: function () {
        var layers = [];
        this.eachLayer(function (l) {
            layers.push(l);
        });
        return layers;
    },

    //Overrides LayerGroup.getLayer, WARNING: Really bad performance
    getLayer: function (id) {
        var result = null;

        this.eachLayer(function (l) {
            if (L.stamp(l) === id) {
                result = l;
            }
        });

        return result;
    },

    //Returns true if the given layer is in this MarkerClusterGroup
    hasLayer: function (layer) {
        if (!layer) {
            return false;
        }

        var i, anArray = this._needsClustering;

        for (i = anArray.length - 1; i >= 0; i--) {
            if (anArray[i] === layer) {
                return true;
            }
        }

        anArray = this._needsRemoving;
        for (i = anArray.length - 1; i >= 0; i--) {
            if (anArray[i] === layer) {
                return false;
            }
        }

        return !!(layer.__parent && layer.__parent._group === this) || this._nonPointGroup.hasLayer(layer);
    },

    //Zoom down to show the given layer (spiderfying if necessary) then calls the callback
    zoomToShowLayer: function (layer, callback) {

        var showMarker = function () {
            if ((layer._icon || layer.__parent._icon) && !this._inZoomAnimation) {
                this._map.off('moveend', showMarker, this);
                this.off('animationend', showMarker, this);

                if (layer._icon) {
                    callback();
                } else if (layer.__parent._icon) {
                    var afterSpiderfy = function () {
                        this.off('spiderfied', afterSpiderfy, this);
                        callback();
                    };

                    this.on('spiderfied', afterSpiderfy, this);
                    layer.__parent.spiderfy();
                }
            }
        };

        if (layer._icon && this._map.getBounds().contains(layer.getLatLng())) {
            callback();
        } else if (layer.__parent._zoom < this._map.getZoom()) {
            //Layer should be visible now but isn't on screen, just pan over to it
            this._map.on('moveend', showMarker, this);
            this._map.panTo(layer.getLatLng());
        } else {
            this._map.on('moveend', showMarker, this);
            this.on('animationend', showMarker, this);
            this._map.setView(layer.getLatLng(), layer.__parent._zoom + 1);
            layer.__parent.zoomToBounds();
        }
    },

    //Overrides FeatureGroup.onAdd
    onAdd: function (map) {
        this._map = map;
        var i, l, layer;

        if (!isFinite(this._map.getMaxZoom())) {
            throw "Map has no maxZoom specified";
        }

        this._featureGroup.addTo(map);
        this._nonPointGroup.addTo(map);

        if (!this._gridClusters) {
            this._generateInitialClusters();
        }

        for (i = 0, l = this._needsRemoving.length; i < l; i++) {
            layer = this._needsRemoving[i];
            this._removeLayer(layer, true);
        }
        this._needsRemoving = [];

        //Remember the current zoom level and bounds
        this._zoom = this._map.getZoom();
        this._currentShownBounds = this._getExpandedVisibleBounds();

        this._map.on('zoomend', this._zoomEnd, this);
        this._map.on('moveend', this._moveEnd, this);

        if (this._spiderfierOnAdd) { //TODO FIXME: Not sure how to have spiderfier add something on here nicely
            this._spiderfierOnAdd();
        }

        this._bindEvents();

        //Actually add our markers to the map:
        l = this._needsClustering;
        this._needsClustering = [];
        this.addLayers(l);
    },

    //Overrides FeatureGroup.onRemove
    onRemove: function (map) {
        map.off('zoomend', this._zoomEnd, this);
        map.off('moveend', this._moveEnd, this);

        this._unbindEvents();

        //In case we are in a cluster animation
        this._map._mapPane.className = this._map._mapPane.className.replace(' leaflet-cluster-anim', '');

        if (this._spiderfierOnRemove) { //TODO FIXME: Not sure how to have spiderfier add something on here nicely
            this._spiderfierOnRemove();
        }



        //Clean up all the layers we added to the map
        this._hideCoverage();
        this._featureGroup.remove();
        this._nonPointGroup.remove();

        this._featureGroup.clearLayers();

        this._map = null;
    },

    getVisibleParent: function (marker) {
        var vMarker = marker;
        while (vMarker && !vMarker._icon) {
            vMarker = vMarker.__parent;
        }
        return vMarker || null;
    },

    //Remove the given object from the given array
    _arraySplice: function (anArray, obj) {
        for (var i = anArray.length - 1; i >= 0; i--) {
            if (anArray[i] === obj) {
                anArray.splice(i, 1);
                return true;
            }
        }
    },

    _childMarkerMoved: function (e) {
        if (!this._ignoreMove) {
            e.target._latlng = e.oldLatLng;
            this.removeLayer(e.target);

            e.target._latlng = e.latlng;
            this.addLayer(e.target);
        }
        return;
    },

    //Internal function for removing a marker from everything.
    //dontUpdateMap: set to true if you will handle updating the map manually (for bulk functions)
    _removeLayer: function (marker, removeFromDistanceGrid, dontUpdateMap) {
        var gridClusters = this._gridClusters,
            gridUnclustered = this._gridUnclustered,
            fg = this._featureGroup,
            map = this._map;

        //Remove the marker from distance clusters it might be in
        if (removeFromDistanceGrid) {
            for (var z = this._maxZoom; z >= 0; z--) {
                if (!gridUnclustered[z].removeObject(marker, map.project(marker.getLatLng(), z))) {
                    break;
                }
            }
        }

        //Work our way up the clusters removing them as we go if required
        var cluster = marker.__parent,
            markers = cluster._markers,
            otherMarker;

        //Remove the marker from the immediate parents marker list
        this._arraySplice(markers, marker);

        while (cluster) {
            cluster._childCount--;

            if (cluster._zoom < 0) {
                //Top level, do nothing
                break;
            } else if (removeFromDistanceGrid && cluster._childCount <= 1) { //Cluster no longer required
                //We need to push the other marker up to the parent
                otherMarker = cluster._markers[0] === marker ? cluster._markers[1] : cluster._markers[0];

                //Update distance grid
                gridClusters[cluster._zoom].removeObject(cluster, map.project(cluster._cLatLng, cluster._zoom));
                gridUnclustered[cluster._zoom].addObject(otherMarker, map.project(otherMarker.getLatLng(), cluster._zoom));

                //Move otherMarker up to parent
                this._arraySplice(cluster.__parent._childClusters, cluster);
                cluster.__parent._markers.push(otherMarker);
                otherMarker.__parent = cluster.__parent;

                if (cluster._icon) {
                    //Cluster is currently on the map, need to put the marker on the map instead
                    fg.removeLayer(cluster);
                    if (!dontUpdateMap) {
                        fg.addLayer(otherMarker);
                    }
                }
            } else {
                cluster._recalculateBounds();
                if (!dontUpdateMap || !cluster._icon) {
                    cluster._updateIcon();
                }
            }

            cluster = cluster.__parent;
        }

        delete marker.__parent;
    },

    _isOrIsParent: function (el, oel) {
        while (oel) {
            if (el === oel) {
                return true;
            }
            oel = oel.parentNode;
        }
        return false;
    },

    //Override L.Evented.fire
    fire: function (type, data, propagate) {
        if (data && data.layer instanceof L.MarkerCluster) {
            //Prevent multiple clustermouseover/off events if the icon is made up of stacked divs (Doesn't work in ie <= 8, no relatedTarget)
            if (data.originalEvent && this._isOrIsParent(data.layer._icon, data.originalEvent.relatedTarget)) {
                return;
            }
            type = 'cluster' + type;
        }

        L.FeatureGroup.prototype.fire.call(this, type, data, propagate);
    },

    //Override L.Evented.listens
    listens: function (type, propagate) {
        return L.FeatureGroup.prototype.listens.call(this, type, propagate) || L.FeatureGroup.prototype.listens.call(this, 'cluster' + type, propagate);
    },

    //Default functionality
    _defaultIconCreateFunction: function (cluster) {
        var childCount = cluster.getChildCount();

        var c = ' marker-cluster-';
        if (childCount < 10) {
            c += 'small';
        } else if (childCount < 100) {
            c += 'medium';
        } else {
            c += 'large';
        }

        return new L.DivIcon({ html: '<div><span>' + childCount + '</span></div>', className: 'marker-cluster' + c, iconSize: new L.Point(40, 40) });
    },

    _bindEvents: function () {
        var map = this._map,
            spiderfyOnMaxZoom = this.options.spiderfyOnMaxZoom,
            showCoverageOnHover = this.options.showCoverageOnHover,
            zoomToBoundsOnClick = this.options.zoomToBoundsOnClick;

        //Zoom on cluster click or spiderfy if we are at the lowest level
        if (spiderfyOnMaxZoom || zoomToBoundsOnClick) {
            this.on('clusterclick', this._zoomOrSpiderfy, this);
        }

        //Show convex hull (boundary) polygon on mouse over
        if (showCoverageOnHover) {
            this.on('clustermouseover', this._showCoverage, this);
            this.on('clustermouseout', this._hideCoverage, this);
            map.on('zoomend', this._hideCoverage, this);
        }
    },

    _zoomOrSpiderfy: function (e) {
        var map = this._map;
        if (map.getMaxZoom() === map.getZoom()) {
            if (this.options.spiderfyOnMaxZoom) {
                e.layer.spiderfy();
            }
        } else if (this.options.zoomToBoundsOnClick) {
            e.layer.zoomToBounds();
        }

        // Focus the map again for keyboard users.
        if (e.originalEvent && e.originalEvent.keyCode === 13) {
            map._container.focus();
        }
    },

    _showCoverage: function (e) {
        var map = this._map;
        if (this._inZoomAnimation) {
            return;
        }
        if (this._shownPolygon) {
            map.removeLayer(this._shownPolygon);
        }
        if (e.layer.getChildCount() > 2 && e.layer !== this._spiderfied) {
            this._shownPolygon = new L.Polygon(e.layer.getConvexHull(), this.options.polygonOptions);
            map.addLayer(this._shownPolygon);
        }
    },

    _hideCoverage: function () {
        if (this._shownPolygon) {
            this._map.removeLayer(this._shownPolygon);
            this._shownPolygon = null;
        }
    },

    _unbindEvents: function () {
        var spiderfyOnMaxZoom = this.options.spiderfyOnMaxZoom,
            showCoverageOnHover = this.options.showCoverageOnHover,
            zoomToBoundsOnClick = this.options.zoomToBoundsOnClick,
            map = this._map;

        if (spiderfyOnMaxZoom || zoomToBoundsOnClick) {
            this.off('clusterclick', this._zoomOrSpiderfy, this);
        }
        if (showCoverageOnHover) {
            this.off('clustermouseover', this._showCoverage, this);
            this.off('clustermouseout', this._hideCoverage, this);
            map.off('zoomend', this._hideCoverage, this);
        }
    },

    _zoomEnd: function () {
        if (!this._map) { //May have been removed from the map by a zoomEnd handler
            return;
        }
        this._mergeSplitClusters();

        this._zoom = Math.round(this._map._zoom);
        this._currentShownBounds = this._getExpandedVisibleBounds();
    },

    _moveEnd: function () {
        if (this._inZoomAnimation) {
            return;
        }

        var newBounds = this._getExpandedVisibleBounds();

        this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, this._zoom, newBounds);
        this._topClusterLevel._recursivelyAddChildrenToMap(null, Math.round(this._map._zoom), newBounds);

        this._currentShownBounds = newBounds;
        return;
    },

    _generateInitialClusters: function () {
        var maxZoom = this._map.getMaxZoom(),
            radius = this.options.maxClusterRadius,
            radiusFn = radius;

        //If we just set maxClusterRadius to a single number, we need to create
        //a simple function to return that number. Otherwise, we just have to
        //use the function we've passed in.
        if (typeof radius !== "function") {
            radiusFn = function () { return radius; };
        }

        if (this.options.disableClusteringAtZoom) {
            maxZoom = this.options.disableClusteringAtZoom - 1;
        }
        this._maxZoom = maxZoom;
        this._gridClusters = {};
        this._gridUnclustered = {};

        //Set up DistanceGrids for each zoom
        for (var zoom = maxZoom; zoom >= 0; zoom--) {
            this._gridClusters[zoom] = new L.DistanceGrid(radiusFn(zoom));
            this._gridUnclustered[zoom] = new L.DistanceGrid(radiusFn(zoom));
        }

        this._topClusterLevel = new L.MarkerCluster(this, -1);
    },

    //Zoom: Zoom to start adding at (Pass this._maxZoom to start at the bottom)
    _addLayer: function (layer, zoom) {
        var gridClusters = this._gridClusters,
            gridUnclustered = this._gridUnclustered,
            markerPoint, z;

        if (this.options.singleMarkerMode) {
            layer.options.icon = this.options.iconCreateFunction({
                getChildCount: function () {
                    return 1;
                },
                getAllChildMarkers: function () {
                    return [layer];
                }
            });
        }

        layer.on('move', this._childMarkerMoved, this);

        //Find the lowest zoom level to slot this one in
        for (; zoom >= 0; zoom--) {
            markerPoint = this._map.project(layer.getLatLng(), zoom); // calculate pixel position

            //Try find a cluster close by
            var closest = gridClusters[zoom].getNearObject(markerPoint);
            if (closest) {
                closest._addChild(layer);
                layer.__parent = closest;
                return;
            }

            //Try find a marker close by to form a new cluster with
            closest = gridUnclustered[zoom].getNearObject(markerPoint);
            if (closest) {
                var parent = closest.__parent;
                if (parent) {
                    this._removeLayer(closest, false);
                }

                //Create new cluster with these 2 in it

                var newCluster = new L.MarkerCluster(this, zoom, closest, layer);
                gridClusters[zoom].addObject(newCluster, this._map.project(newCluster._cLatLng, zoom));
                closest.__parent = newCluster;
                layer.__parent = newCluster;

                //First create any new intermediate parent clusters that don't exist
                var lastParent = newCluster;
                for (z = zoom - 1; z > parent._zoom; z--) {
                    lastParent = new L.MarkerCluster(this, z, lastParent);
                    gridClusters[z].addObject(lastParent, this._map.project(closest.getLatLng(), z));
                }
                parent._addChild(lastParent);

                //Remove closest from this zoom level and any above that it is in, replace with newCluster
                for (z = zoom; z >= 0; z--) {
                    if (!gridUnclustered[z].removeObject(closest, this._map.project(closest.getLatLng(), z))) {
                        break;
                    }
                }

                return;
            }

            //Didn't manage to cluster in at this zoom, record us as a marker here and continue upwards
            gridUnclustered[zoom].addObject(layer, markerPoint);
        }

        //Didn't get in anything, add us to the top
        this._topClusterLevel._addChild(layer);
        layer.__parent = this._topClusterLevel;
        return;
    },

    //Enqueue code to fire after the marker expand/contract has happened
    _enqueue: function (fn) {
        this._queue.push(fn);
        if (!this._queueTimeout) {
            this._queueTimeout = setTimeout(L.bind(this._processQueue, this), 300);
        }
    },
    _processQueue: function () {
        for (var i = 0; i < this._queue.length; i++) {
            this._queue[i].call(this);
        }
        this._queue.length = 0;
        clearTimeout(this._queueTimeout);
        this._queueTimeout = null;
    },

    //Merge and split any existing clusters that are too big or small
    _mergeSplitClusters: function () {
        var mapZoom = Math.round(this._map._zoom);

        //Incase we are starting to split before the animation finished
        this._processQueue();

        if (this._zoom < mapZoom && this._currentShownBounds.contains(this._getExpandedVisibleBounds())) { //Zoom in, split
            this._animationStart();
            //Remove clusters now off screen
            this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, this._zoom, this._getExpandedVisibleBounds());

            this._animationZoomIn(this._zoom, mapZoom);

        } else if (this._zoom > mapZoom) { //Zoom out, merge
            this._animationStart();

            this._animationZoomOut(this._zoom, mapZoom);
        } else {
            this._moveEnd();
        }
    },

    //Gets the maps visible bounds expanded in each direction by the size of the screen (so the user cannot see an area we do not cover in one pan)
    _getExpandedVisibleBounds: function () {
        if (!this.options.removeOutsideVisibleBounds) {
            return this.getBounds();
        }

        var map = this._map,
            bounds = map.getBounds(),
            sw = bounds._southWest,
            ne = bounds._northEast,
            latDiff = L.Browser.mobile ? 0 : Math.abs(sw.lat - ne.lat),
            lngDiff = L.Browser.mobile ? 0 : Math.abs(sw.lng - ne.lng);

        return new L.LatLngBounds(
            new L.LatLng(sw.lat - latDiff, sw.lng - lngDiff, true),
            new L.LatLng(ne.lat + latDiff, ne.lng + lngDiff, true));
    },

    //Shared animation code
    _animationAddLayerNonAnimated: function (layer, newCluster) {
        if (newCluster === layer) {
            this._featureGroup.addLayer(layer);
        } else if (newCluster._childCount === 2) {
            newCluster._addToMap();

            var markers = newCluster.getAllChildMarkers();
            this._featureGroup.removeLayer(markers[0]);
            this._featureGroup.removeLayer(markers[1]);
        } else {
            newCluster._updateIcon();
        }
    }
});

L.MarkerClusterGroup.include(!L.DomUtil.TRANSITION ? {

    //Non Animated versions of everything
    _animationStart: function () {
        //Do nothing...
    },
    _animationZoomIn: function (previousZoomLevel, newZoomLevel) {
        this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, previousZoomLevel);
        this._topClusterLevel._recursivelyAddChildrenToMap(null, newZoomLevel, this._getExpandedVisibleBounds());

        //We didn't actually animate, but we use this event to mean "clustering animations have finished"
        this.fire('animationend');
    },
    _animationZoomOut: function (previousZoomLevel, newZoomLevel) {
        this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, previousZoomLevel);
        this._topClusterLevel._recursivelyAddChildrenToMap(null, newZoomLevel, this._getExpandedVisibleBounds());

        //We didn't actually animate, but we use this event to mean "clustering animations have finished"
        this.fire('animationend');
    },
    _animationAddLayer: function (layer, newCluster) {
        this._animationAddLayerNonAnimated(layer, newCluster);
    }
} : {

    //Animated versions here
    _animationStart: function () {
        this._map._mapPane.className += ' leaflet-cluster-anim';
        this._inZoomAnimation++;
    },
    _animationEnd: function () {
        if (this._map) {
            this._map._mapPane.className = this._map._mapPane.className.replace(' leaflet-cluster-anim', '');
        }
        this._inZoomAnimation--;
        this.fire('animationend');
    },
    _animationZoomIn: function (previousZoomLevel, newZoomLevel) {
        var bounds = this._getExpandedVisibleBounds(),
            fg = this._featureGroup,
            i;

        this._ignoreMove = true;

        //Add all children of current clusters to map and remove those clusters from map
        this._topClusterLevel._recursively(bounds, previousZoomLevel, 0, function (c) {
            var startPos = c._latlng,
                markers = c._markers,
                m;

            if (!bounds.contains(startPos)) {
                startPos = null;
            }

            if (c._isSingleParent() && previousZoomLevel + 1 === newZoomLevel) { //Immediately add the new child and remove us
                fg.removeLayer(c);
                c._recursivelyAddChildrenToMap(null, newZoomLevel, bounds);
            } else {
                //Fade out old cluster
                c.setOpacity(0);
                c._recursivelyAddChildrenToMap(startPos, newZoomLevel, bounds);
            }

            //Remove all markers that aren't visible any more
            //TODO: Do we actually need to do this on the higher levels too?
            for (i = markers.length - 1; i >= 0; i--) {
                m = markers[i];
                if (!bounds.contains(m._latlng)) {
                    fg.removeLayer(m);
                }
            }

        });

        this._forceLayout();

        //Update opacities
        this._topClusterLevel._recursivelyBecomeVisible(bounds, newZoomLevel);
        //TODO Maybe? Update markers in _recursivelyBecomeVisible
        fg.eachLayer(function (n) {
            if (!(n instanceof L.MarkerCluster) && n._icon) {
                n.setOpacity(1);
            }
        });

        //update the positions of the just added clusters/markers
        this._topClusterLevel._recursively(bounds, previousZoomLevel, newZoomLevel, function (c) {
            c._recursivelyRestoreChildPositions(newZoomLevel);
        });

        this._ignoreMove = false;

        //Remove the old clusters and close the zoom animation
        this._enqueue(function () {
            //update the positions of the just added clusters/markers
            this._topClusterLevel._recursively(bounds, previousZoomLevel, 0, function (c) {
                fg.removeLayer(c);
                c.setOpacity(1);
            });

            this._animationEnd();
        });
    },

    _animationZoomOut: function (previousZoomLevel, newZoomLevel) {
        this._animationZoomOutSingle(this._topClusterLevel, previousZoomLevel - 1, newZoomLevel);

        //Need to add markers for those that weren't on the map before but are now
        this._topClusterLevel._recursivelyAddChildrenToMap(null, newZoomLevel, this._getExpandedVisibleBounds());
        //Remove markers that were on the map before but won't be now
        this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, previousZoomLevel, this._getExpandedVisibleBounds());
    },
    _animationZoomOutSingle: function (cluster, previousZoomLevel, newZoomLevel) {
        var bounds = this._getExpandedVisibleBounds();

        //Animate all of the markers in the clusters to move to their cluster center point
        cluster._recursivelyAnimateChildrenInAndAddSelfToMap(bounds, previousZoomLevel + 1, newZoomLevel);

        var me = this;

        //Update the opacity (If we immediately set it they won't animate)
        this._forceLayout();
        cluster._recursivelyBecomeVisible(bounds, newZoomLevel);

        //TODO: Maybe use the transition timing stuff to make this more reliable
        //When the animations are done, tidy up
        this._enqueue(function () {

            //This cluster stopped being a cluster before the timeout fired
            if (cluster._childCount === 1) {
                var m = cluster._markers[0];
                //If we were in a cluster animation at the time then the opacity and position of our child could be wrong now, so fix it
                this._ignoreMove = true;
                m.setLatLng(m.getLatLng());
                this._ignoreMove = false;
                if (m.setOpacity) {
                    m.setOpacity(1);
                }
            } else {
                cluster._recursively(bounds, newZoomLevel, 0, function (c) {
                    c._recursivelyRemoveChildrenFromMap(bounds, previousZoomLevel + 1);
                });
            }
            me._animationEnd();
        });
    },
    _animationAddLayer: function (layer, newCluster) {
        var me = this,
            fg = this._featureGroup;

        fg.addLayer(layer);
        if (newCluster !== layer) {
            if (newCluster._childCount > 2) { //Was already a cluster

                newCluster._updateIcon();
                this._forceLayout();
                this._animationStart();

                layer._setPos(this._map.latLngToLayerPoint(newCluster.getLatLng()));
                layer.setOpacity(0);

                this._enqueue(function () {
                    fg.removeLayer(layer);
                    layer.setOpacity(1);

                    me._animationEnd();
                });

            } else { //Just became a cluster
                this._forceLayout();

                me._animationStart();
                me._animationZoomOutSingle(newCluster, this._map.getMaxZoom(), this._map.getZoom());
            }
        }
    },

    //Force a browser layout of stuff in the map
    // Should apply the current opacity and location to all elements so we can update them again for an animation
    _forceLayout: function () {
        //In my testing this works, infact offsetWidth of any element seems to work.
        //Could loop all this._layers and do this for each _icon if it stops working

        L.Util.falseFn(document.body.offsetWidth);
    }
});

L.markerClusterGroup = function (options) {
    return new L.MarkerClusterGroup(options);
};


L.MarkerCluster = L.Marker.extend({
    initialize: function (group, zoom, a, b) {

        L.Marker.prototype.initialize.call(this, a ? (a._cLatLng || a.getLatLng()) : new L.LatLng(0, 0), { icon: this });


        this._group = group;
        this._zoom = zoom;

        this._markers = [];
        this._childClusters = [];
        this._childCount = 0;
        this._iconNeedsUpdate = true;

        this._bounds = new L.LatLngBounds();

        if (a) {
            this._addChild(a);
        }
        if (b) {
            this._addChild(b);
        }
    },

    //Recursively retrieve all child markers of this cluster
    getAllChildMarkers: function (storageArray) {
        storageArray = storageArray || [];

        for (var i = this._childClusters.length - 1; i >= 0; i--) {
            this._childClusters[i].getAllChildMarkers(storageArray);
        }

        for (var j = this._markers.length - 1; j >= 0; j--) {
            storageArray.push(this._markers[j]);
        }

        return storageArray;
    },

    //Returns the count of how many child markers we have
    getChildCount: function () {
        return this._childCount;
    },

    //Zoom to the minimum of showing all of the child markers, or the extents of this cluster
    zoomToBounds: function () {
        var childClusters = this._childClusters.slice(),
            map = this._group._map,
            boundsZoom = map.getBoundsZoom(this._bounds),
            zoom = this._zoom + 1,
            mapZoom = map.getZoom(),
            i;

        //calculate how fare we need to zoom down to see all of the markers
        while (childClusters.length > 0 && boundsZoom > zoom) {
            zoom++;
            var newClusters = [];
            for (i = 0; i < childClusters.length; i++) {
                newClusters = newClusters.concat(childClusters[i]._childClusters);
            }
            childClusters = newClusters;
        }

        if (boundsZoom > zoom) {
            this._group._map.setView(this._latlng, zoom);
        } else if (boundsZoom <= mapZoom) { //If fitBounds wouldn't zoom us down, zoom us down instead
            this._group._map.setView(this._latlng, mapZoom + 1);
        } else {
            this._group._map.fitBounds(this._bounds);
        }
    },

    getBounds: function () {
        var bounds = new L.LatLngBounds();
        bounds.extend(this._bounds);
        return bounds;
    },

    _updateIcon: function () {
        this._iconNeedsUpdate = true;
        if (this._icon) {
            this.setIcon(this);
        }
    },

    //Cludge for Icon, we pretend to be an icon for performance
    createIcon: function () {
        if (this._iconNeedsUpdate) {
            this._iconObj = this._group.options.iconCreateFunction(this);
            this._iconNeedsUpdate = false;
        }
        return this._iconObj.createIcon();
    },
    createShadow: function () {
        return this._iconObj.createShadow();
    },


    _addChild: function (new1, isNotificationFromChild) {

        this._iconNeedsUpdate = true;
        this._expandBounds(new1);

        if (new1 instanceof L.MarkerCluster) {
            if (!isNotificationFromChild) {
                this._childClusters.push(new1);
                new1.__parent = this;
            }
            this._childCount += new1._childCount;
        } else {
            if (!isNotificationFromChild) {
                this._markers.push(new1);
            }
            this._childCount++;
        }

        if (this.__parent) {
            this.__parent._addChild(new1, true);
        }
    },

    //Expand our bounds and tell our parent to
    _expandBounds: function (marker) {
        var addedCount,
            addedLatLng = marker._wLatLng || marker._latlng;

        if (marker instanceof L.MarkerCluster) {
            this._bounds.extend(marker._bounds);
            addedCount = marker._childCount;
        } else {
            this._bounds.extend(addedLatLng);
            addedCount = 1;
        }

        if (!this._cLatLng) {
            // when clustering, take position of the first point as the cluster center
            this._cLatLng = marker._cLatLng || addedLatLng;
        }

        // when showing clusters, take weighted average of all points as cluster center
        var totalCount = this._childCount + addedCount;

        //Calculate weighted latlng for display
        if (!this._wLatLng) {
            this._latlng = this._wLatLng = new L.LatLng(addedLatLng.lat, addedLatLng.lng);
        } else {
            this._wLatLng.lat = (addedLatLng.lat * addedCount + this._wLatLng.lat * this._childCount) / totalCount;
            this._wLatLng.lng = (addedLatLng.lng * addedCount + this._wLatLng.lng * this._childCount) / totalCount;
        }
    },

    //Set our markers position as given and add it to the map
    _addToMap: function (startPos) {
        if (startPos) {
            this._backupLatlng = this._latlng;
            this.setLatLng(startPos);
        }
        this._group._featureGroup.addLayer(this);
    },

    _recursivelyAnimateChildrenIn: function (bounds, center, maxZoom) {
        this._recursively(bounds, 0, maxZoom - 1,
            function (c) {
                var markers = c._markers,
                    i, m;
                for (i = markers.length - 1; i >= 0; i--) {
                    m = markers[i];

                    //Only do it if the icon is still on the map
                    if (m._icon) {
                        m._setPos(center);
                        m.setOpacity(0);
                    }
                }
            },
            function (c) {
                var childClusters = c._childClusters,
                    j, cm;
                for (j = childClusters.length - 1; j >= 0; j--) {
                    cm = childClusters[j];
                    if (cm._icon) {
                        cm._setPos(center);
                        cm.setOpacity(0);
                    }
                }
            }
        );
    },

    _recursivelyAnimateChildrenInAndAddSelfToMap: function (bounds, previousZoomLevel, newZoomLevel) {
        this._recursively(bounds, newZoomLevel, 0,
            function (c) {
                c._recursivelyAnimateChildrenIn(bounds, c._group._map.latLngToLayerPoint(c.getLatLng()).round(), previousZoomLevel);

                //TODO: depthToAnimateIn affects _isSingleParent, if there is a multizoom we may/may not be.
                //As a hack we only do a animation free zoom on a single level zoom, if someone does multiple levels then we always animate
                if (c._isSingleParent() && previousZoomLevel - 1 === newZoomLevel) {
                    c.setOpacity(1);
                    c._recursivelyRemoveChildrenFromMap(bounds, previousZoomLevel); //Immediately remove our children as we are replacing them. TODO previousBounds not bounds
                } else {
                    c.setOpacity(0);
                }

                c._addToMap();
            }
        );
    },

    _recursivelyBecomeVisible: function (bounds, zoomLevel) {
        this._recursively(bounds, 0, zoomLevel, null, function (c) {
            c.setOpacity(1);
        });
    },

    _recursivelyAddChildrenToMap: function (startPos, zoomLevel, bounds) {
        this._recursively(bounds, -1, zoomLevel,
            function (c) {
                if (zoomLevel === c._zoom) {
                    return;
                }

                //Add our child markers at startPos (so they can be animated out)
                for (var i = c._markers.length - 1; i >= 0; i--) {
                    var nm = c._markers[i];

                    if (!bounds.contains(nm._latlng)) {
                        continue;
                    }

                    if (startPos) {
                        nm._backupLatlng = nm.getLatLng();

                        nm.setLatLng(startPos);
                        if (nm.setOpacity) {
                            nm.setOpacity(0);
                        }
                    }

                    c._group._featureGroup.addLayer(nm);
                }
            },
            function (c) {
                c._addToMap(startPos);
            }
        );
    },

    _recursivelyRestoreChildPositions: function (zoomLevel) {
        //Fix positions of child markers
        for (var i = this._markers.length - 1; i >= 0; i--) {
            var nm = this._markers[i];
            if (nm._backupLatlng) {
                nm.setLatLng(nm._backupLatlng);
                delete nm._backupLatlng;
            }
        }

        if (zoomLevel - 1 === this._zoom) {
            //Reposition child clusters
            for (var j = this._childClusters.length - 1; j >= 0; j--) {
                this._childClusters[j]._restorePosition();
            }
        } else {
            for (var k = this._childClusters.length - 1; k >= 0; k--) {
                this._childClusters[k]._recursivelyRestoreChildPositions(zoomLevel);
            }
        }
    },

    _restorePosition: function () {
        if (this._backupLatlng) {
            this.setLatLng(this._backupLatlng);
            delete this._backupLatlng;
        }
    },

    //exceptBounds: If set, don't remove any markers/clusters in it
    _recursivelyRemoveChildrenFromMap: function (previousBounds, zoomLevel, exceptBounds) {
        var m, i;
        this._recursively(previousBounds, -1, zoomLevel - 1,
            function (c) {
                //Remove markers at every level
                for (i = c._markers.length - 1; i >= 0; i--) {
                    m = c._markers[i];
                    if (!exceptBounds || !exceptBounds.contains(m._latlng)) {
                        c._group._featureGroup.removeLayer(m);
                        if (m.setOpacity) {
                            m.setOpacity(1);
                        }
                    }
                }
            },
            function (c) {
                //Remove child clusters at just the bottom level
                for (i = c._childClusters.length - 1; i >= 0; i--) {
                    m = c._childClusters[i];
                    if (!exceptBounds || !exceptBounds.contains(m._latlng)) {
                        c._group._featureGroup.removeLayer(m);
                        if (m.setOpacity) {
                            m.setOpacity(1);
                        }
                    }
                }
            }
        );
    },

    //Run the given functions recursively to this and child clusters
    // boundsToApplyTo: a L.LatLngBounds representing the bounds of what clusters to recurse in to
    // zoomLevelToStart: zoom level to start running functions (inclusive)
    // zoomLevelToStop: zoom level to stop running functions (inclusive)
    // runAtEveryLevel: function that takes an L.MarkerCluster as an argument that should be applied on every level
    // runAtBottomLevel: function that takes an L.MarkerCluster as an argument that should be applied at only the bottom level
    _recursively: function (boundsToApplyTo, zoomLevelToStart, zoomLevelToStop, runAtEveryLevel, runAtBottomLevel) {
        var childClusters = this._childClusters,
            zoom = this._zoom,
            i, c;

        if (zoomLevelToStart > zoom) { //Still going down to required depth, just recurse to child clusters
            for (i = childClusters.length - 1; i >= 0; i--) {
                c = childClusters[i];
                if (boundsToApplyTo.intersects(c._bounds)) {
                    c._recursively(boundsToApplyTo, zoomLevelToStart, zoomLevelToStop, runAtEveryLevel, runAtBottomLevel);
                }
            }
        } else { //In required depth

            if (runAtEveryLevel) {
                runAtEveryLevel(this);
            }
            if (runAtBottomLevel && this._zoom === zoomLevelToStop) {
                runAtBottomLevel(this);
            }

            //TODO: This loop is almost the same as above
            if (zoomLevelToStop > zoom) {
                for (i = childClusters.length - 1; i >= 0; i--) {
                    c = childClusters[i];
                    if (boundsToApplyTo.intersects(c._bounds)) {
                        c._recursively(boundsToApplyTo, zoomLevelToStart, zoomLevelToStop, runAtEveryLevel, runAtBottomLevel);
                    }
                }
            }
        }
    },

    _recalculateBounds: function () {
        var markers = this._markers,
            childClusters = this._childClusters,
            i;

        this._bounds = new L.LatLngBounds();
        delete this._wLatLng;

        for (i = markers.length - 1; i >= 0; i--) {
            this._expandBounds(markers[i]);
        }
        for (i = childClusters.length - 1; i >= 0; i--) {
            this._expandBounds(childClusters[i]);
        }
    },


    //Returns true if we are the parent of only one cluster and that cluster is the same as us
    _isSingleParent: function () {
        //Don't need to check this._markers as the rest won't work if there are any
        return this._childClusters.length > 0 && this._childClusters[0]._childCount === this._childCount;
    }
});



L.DistanceGrid = function (cellSize) {
    this._cellSize = cellSize;
    this._sqCellSize = cellSize * cellSize;
    this._grid = {};
    this._objectPoint = { };
};

L.DistanceGrid.prototype = {

    addObject: function (obj, point) {
        var x = this._getCoord(point.x),
            y = this._getCoord(point.y),
            grid = this._grid,
            row = grid[y] = grid[y] || {},
            cell = row[x] = row[x] || [],
            stamp = L.Util.stamp(obj);

        this._objectPoint[stamp] = point;

        cell.push(obj);
    },

    updateObject: function (obj, point) {
        this.removeObject(obj);
        this.addObject(obj, point);
    },

    //Returns true if the object was found
    removeObject: function (obj, point) {
        var x = this._getCoord(point.x),
            y = this._getCoord(point.y),
            grid = this._grid,
            row = grid[y] = grid[y] || {},
            cell = row[x] = row[x] || [],
            i, len;

        delete this._objectPoint[L.Util.stamp(obj)];

        for (i = 0, len = cell.length; i < len; i++) {
            if (cell[i] === obj) {

                cell.splice(i, 1);

                if (len === 1) {
                    delete row[x];
                }

                return true;
            }
        }

    },

    eachObject: function (fn, context) {
        var i, j, k, len, row, cell, removed,
            grid = this._grid;

        for (i in grid) {
            row = grid[i];

            for (j in row) {
                cell = row[j];

                for (k = 0, len = cell.length; k < len; k++) {
                    removed = fn.call(context, cell[k]);
                    if (removed) {
                        k--;
                        len--;
                    }
                }
            }
        }
    },

    getNearObject: function (point) {
        var x = this._getCoord(point.x),
            y = this._getCoord(point.y),
            i, j, k, row, cell, len, obj, dist,
            objectPoint = this._objectPoint,
            closestDistSq = this._sqCellSize,
            closest = null;

        for (i = y - 1; i <= y + 1; i++) {
            row = this._grid[i];
            if (row) {

                for (j = x - 1; j <= x + 1; j++) {
                    cell = row[j];
                    if (cell) {

                        for (k = 0, len = cell.length; k < len; k++) {
                            obj = cell[k];
                            dist = this._sqDist(objectPoint[L.Util.stamp(obj)], point);
                            if (dist < closestDistSq) {
                                closestDistSq = dist;
                                closest = obj;
                            }
                        }
                    }
                }
            }
        }
        return closest;
    },

    _getCoord: function (x) {
        return Math.floor(x / this._cellSize);
    },

    _sqDist: function (p, p2) {
        var dx = p2.x - p.x,
            dy = p2.y - p.y;
        return dx * dx + dy * dy;
    }
};


/* Copyright (c) 2012 the authors listed at the following URL, and/or
the authors of referenced articles or incorporated external code:
http://en.literateprograms.org/Quickhull_(Javascript)?action=history&offset=20120410175256

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Retrieved from: http://en.literateprograms.org/Quickhull_(Javascript)?oldid=18434
*/

(function () {
    L.QuickHull = {

        /*
         * @param {Object} cpt a point to be measured from the baseline
         * @param {Array} bl the baseline, as represented by a two-element
         *   array of latlng objects.
         * @returns {Number} an approximate distance measure
         */
        getDistant: function (cpt, bl) {
            var vY = bl[1].lat - bl[0].lat,
                vX = bl[0].lng - bl[1].lng;
            return (vX * (cpt.lat - bl[0].lat) + vY * (cpt.lng - bl[0].lng));
        },

        /*
         * @param {Array} baseLine a two-element array of latlng objects
         *   representing the baseline to project from
         * @param {Array} latLngs an array of latlng objects
         * @returns {Object} the maximum point and all new points to stay
         *   in consideration for the hull.
         */
        findMostDistantPointFromBaseLine: function (baseLine, latLngs) {
            var maxD = 0,
                maxPt = null,
                newPoints = [],
                i, pt, d;

            for (i = latLngs.length - 1; i >= 0; i--) {
                pt = latLngs[i];
                d = this.getDistant(pt, baseLine);

                if (d > 0) {
                    newPoints.push(pt);
                } else {
                    continue;
                }

                if (d > maxD) {
                    maxD = d;
                    maxPt = pt;
                }
            }

            return { maxPoint: maxPt, newPoints: newPoints };
        },


        /*
         * Given a baseline, compute the convex hull of latLngs as an array
         * of latLngs.
         *
         * @param {Array} latLngs
         * @returns {Array}
         */
        buildConvexHull: function (baseLine, latLngs) {
            var convexHullBaseLines = [],
                t = this.findMostDistantPointFromBaseLine(baseLine, latLngs);

            if (t.maxPoint) { // if there is still a point "outside" the base line
                convexHullBaseLines =
                    convexHullBaseLines.concat(
                        this.buildConvexHull([baseLine[0], t.maxPoint], t.newPoints)
                    );
                convexHullBaseLines =
                    convexHullBaseLines.concat(
                        this.buildConvexHull([t.maxPoint, baseLine[1]], t.newPoints)
                    );
                return convexHullBaseLines;
            } else {  // if there is no more point "outside" the base line, the current base line is part of the convex hull
                return [baseLine[0]];
            }
        },

        /*
         * Given an array of latlngs, compute a convex hull as an array
         * of latlngs
         *
         * @param {Array} latLngs
         * @returns {Array}
         */
        getConvexHull: function (latLngs) {
            // find first baseline
            var maxLat = false, minLat = false,
                maxPt = null, minPt = null,
                i;

            for (i = latLngs.length - 1; i >= 0; i--) {
                var pt = latLngs[i];
                if (maxLat === false || pt.lat > maxLat) {
                    maxPt = pt;
                    maxLat = pt.lat;
                }
                if (minLat === false || pt.lat < minLat) {
                    minPt = pt;
                    minLat = pt.lat;
                }
            }
            var ch = [].concat(this.buildConvexHull([minPt, maxPt], latLngs),
                                this.buildConvexHull([maxPt, minPt], latLngs));
            return ch;
        }
    };
}());

L.MarkerCluster.include({
    getConvexHull: function () {
        var childMarkers = this.getAllChildMarkers(),
            points = [],
            p, i;

        for (i = childMarkers.length - 1; i >= 0; i--) {
            p = childMarkers[i].getLatLng();
            points.push(p);
        }

        return L.QuickHull.getConvexHull(points);
    }
});


//This code is 100% based on https://github.com/jawj/OverlappingMarkerSpiderfier-Leaflet
//Huge thanks to jawj for implementing it first to make my job easy :-)

L.MarkerCluster.include({

    _2PI: Math.PI * 2,
    _circleFootSeparation: 25, //related to circumference of circle
    _circleStartAngle: Math.PI / 6,

    _spiralFootSeparation:  28, //related to size of spiral (experiment!)
    _spiralLengthStart: 11,
    _spiralLengthFactor: 5,

    _circleSpiralSwitchover: 9, //show spiral instead of circle from this marker count upwards.
                                // 0 -> always spiral; Infinity -> always circle

    spiderfy: function () {
        if (this._group._spiderfied === this || this._group._inZoomAnimation) {
            return;
        }

        var childMarkers = this.getAllChildMarkers(),
            group = this._group,
            map = group._map,
            center = map.latLngToLayerPoint(this._latlng),
            positions;

        this._group._unspiderfy();
        this._group._spiderfied = this;

        //TODO Maybe: childMarkers order by distance to center

        if (childMarkers.length >= this._circleSpiralSwitchover) {
            positions = this._generatePointsSpiral(childMarkers.length, center);
        } else {
            center.y += 10; //Otherwise circles look wrong
            positions = this._generatePointsCircle(childMarkers.length, center);
        }

        this._animationSpiderfy(childMarkers, positions);
    },

    unspiderfy: function (zoomDetails) {
        /// <param Name="zoomDetails">Argument from zoomanim if being called in a zoom animation or null otherwise</param>
        if (this._group._inZoomAnimation) {
            return;
        }
        this._animationUnspiderfy(zoomDetails);

        this._group._spiderfied = null;
    },

    _generatePointsCircle: function (count, centerPt) {
        var circumference = this._group.options.spiderfyDistanceMultiplier * this._circleFootSeparation * (2 + count),
            legLength = circumference / this._2PI,  //radius from circumference
            angleStep = this._2PI / count,
            res = [],
            i, angle;

        res.length = count;

        for (i = count - 1; i >= 0; i--) {
            angle = this._circleStartAngle + i * angleStep;
            res[i] = new L.Point(centerPt.x + legLength * Math.cos(angle), centerPt.y + legLength * Math.sin(angle))._round();
        }

        return res;
    },

    _generatePointsSpiral: function (count, centerPt) {
        var legLength = this._group.options.spiderfyDistanceMultiplier * this._spiralLengthStart,
            separation = this._group.options.spiderfyDistanceMultiplier * this._spiralFootSeparation,
            lengthFactor = this._group.options.spiderfyDistanceMultiplier * this._spiralLengthFactor,
            angle = 0,
            res = [],
            i;

        res.length = count;

        for (i = count - 1; i >= 0; i--) {
            angle += separation / legLength + i * 0.0005;
            res[i] = new L.Point(centerPt.x + legLength * Math.cos(angle), centerPt.y + legLength * Math.sin(angle))._round();
            legLength += this._2PI * lengthFactor / angle;
        }
        return res;
    },

    _noanimationUnspiderfy: function () {
        var group = this._group,
            map = group._map,
            fg = group._featureGroup,
            childMarkers = this.getAllChildMarkers(),
            m, i;

        group._ignoreMove = true;

        this.setOpacity(1);
        for (i = childMarkers.length - 1; i >= 0; i--) {
            m = childMarkers[i];

            fg.removeLayer(m);

            if (m._preSpiderfyLatlng) {
                m.setLatLng(m._preSpiderfyLatlng);
                delete m._preSpiderfyLatlng;
            }
            if (m.setZIndexOffset) {
                m.setZIndexOffset(0);
            }

            if (m._spiderLeg) {
                map.removeLayer(m._spiderLeg);
                delete m._spiderLeg;
            }
        }

        group._ignoreMove = false;
        group._spiderfied = null;
    }
});

L.MarkerCluster.include(!L.DomUtil.TRANSITION ? {
    //Non Animated versions of everything
    _animationSpiderfy: function (childMarkers, positions) {
        var group = this._group,
            map = group._map,
            fg = group._featureGroup,
            i, m, leg, newPos;

        group._ignoreMove = true;

        for (i = childMarkers.length - 1; i >= 0; i--) {
            newPos = map.layerPointToLatLng(positions[i]);
            m = childMarkers[i];

            m._preSpiderfyLatlng = m._latlng;
            m.setLatLng(newPos);
            if (m.setZIndexOffset) {
                m.setZIndexOffset(1000000); //Make these appear on top of EVERYTHING
            }

            fg.addLayer(m);


            leg = new L.Polyline([this._latlng, newPos], { weight: 1.5, color: '#222' });
            map.addLayer(leg);
            m._spiderLeg = leg;
        }
        this.setOpacity(0.3);

        group._ignoreMove = false;
        group.fire('spiderfied');
    },

    _animationUnspiderfy: function () {
        this._noanimationUnspiderfy();
    }
} : {
    //Animated versions here
    SVG_ANIMATION: (function () {
        return document.createElementNS('http://www.w3.org/2000/svg', 'animate').toString().indexOf('SVGAnimate') > -1;
    }()),

    _animationSpiderfy: function (childMarkers, positions) {
        var me = this,
            group = this._group,
            map = group._map,
            fg = group._featureGroup,
            thisLayerPos = map.latLngToLayerPoint(this._latlng),
            xmlns = 'http://www.w3.org/2000/svg',
            i, m, leg, newPos;

        group._ignoreMove = true;

        //Add markers to map hidden at our center point
        for (i = childMarkers.length - 1; i >= 0; i--) {
            m = childMarkers[i];

            //If it is a marker, add it now and we'll animate it out
            if (m.setOpacity) {
                m.setZIndexOffset(1000000); //Make these appear on top of EVERYTHING
                m.setOpacity(0);

                fg.addLayer(m);

                m._setPos(thisLayerPos);
            } else {
                //Vectors just get immediately added
                fg.addLayer(m);
            }
        }

        group._forceLayout();
        group._animationStart();

        var initialLegOpacity = this.SVG_ANIMATION ? 0 : 0.3;

        for (i = childMarkers.length - 1; i >= 0; i--) {
            newPos = map.layerPointToLatLng(positions[i]);
            m = childMarkers[i];

            //Move marker to new position
            m._preSpiderfyLatlng = m._latlng;
            m.setLatLng(newPos);

            if (m.setOpacity) {
                m.setOpacity(1);
            }


            //Add Legs. Force the SVG renderer so we can animate
            leg = new L.Polyline([me._latlng, newPos], { weight: 1.5, color: '#222', opacity: initialLegOpacity });
            map.addLayer(leg);
            m._spiderLeg = leg;

            //Following animations don't work for canvas or browsers that don't support animated svg
            if (this.SVG_ANIMATION) {
                //How this works:
                //http://stackoverflow.com/questions/5924238/how-do-you-animate-an-svg-path-in-ios
                //http://dev.opera.com/articles/view/advanced-svg-animation-techniques/

                //Animate length
                var length = leg._path.getTotalLength();
                leg._path.setAttribute("stroke-dasharray", length + "," + length);

                var anim = document.createElementNS(xmlns, "animate");
                anim.setAttribute("attributeName", "stroke-dashoffset");
                anim.setAttribute("begin", "indefinite");
                anim.setAttribute("from", length);
                anim.setAttribute("to", 0);
                anim.setAttribute("dur", 0.25);
                leg._path.appendChild(anim);
                anim.beginElement();

                //Animate opacity
                anim = document.createElementNS(xmlns, "animate");
                anim.setAttribute("attributeName", "stroke-opacity");
                anim.setAttribute("attributeName", "stroke-opacity");
                anim.setAttribute("begin", "indefinite");
                anim.setAttribute("from", 0);
                anim.setAttribute("to", 0.3);
                anim.setAttribute("dur", 0.25);
                leg._path.appendChild(anim);
                anim.beginElement();
            }
        }
        me.setOpacity(0.3);

        //Set the opacity of the spiderLegs back to their correct value
        // The animations above override this until they complete.
        // If the initial opacity of the spiderlegs isn't 0 then they appear before the animation starts.
        this._group._forceLayout();

        for (i = childMarkers.length - 1; i >= 0; i--) {
            m = childMarkers[i]._spiderLeg;

            m.options.opacity = 0.5;
            m._path.setAttribute('stroke-opacity', 0.5);
        }

        group._ignoreMove = false;

        setTimeout(function () {
            group._animationEnd();
            group.fire('spiderfied');
        }, 200);
    },

    _animationUnspiderfy: function (zoomDetails) {
        var group = this._group,
            map = group._map,
            fg = group._featureGroup,
            thisLayerPos = zoomDetails ? map._latLngToNewLayerPoint(this._latlng, zoomDetails.zoom, zoomDetails.center) : map.latLngToLayerPoint(this._latlng),
            childMarkers = this.getAllChildMarkers(),
            m, i, a;

        group._ignoreMove = true;
        group._animationStart();

        //Make us visible and bring the child markers back in
        this.setOpacity(1);
        for (i = childMarkers.length - 1; i >= 0; i--) {
            m = childMarkers[i];

            //Marker was added to us after we were spidified
            if (!m._preSpiderfyLatlng) {
                continue;
            }

            //Fix up the location to the real one
            m.setLatLng(m._preSpiderfyLatlng);
            delete m._preSpiderfyLatlng;
            //Hack override the location to be our center
            if (m.setOpacity) {
                m._setPos(thisLayerPos);
                m.setOpacity(0);
            } else {
                fg.removeLayer(m);
            }

            //Animate the spider legs back in
            if (this.SVG_ANIMATION) {
                a = m._spiderLeg._path.childNodes[0];
                a.setAttribute('to', a.getAttribute('from'));
                a.setAttribute('from', 0);
                a.beginElement();

                a = m._spiderLeg._path.childNodes[1];
                a.setAttribute('from', 0.5);
                a.setAttribute('to', 0);
                a.setAttribute('stroke-opacity', 0);
                a.beginElement();

                m._spiderLeg._path.setAttribute('stroke-opacity', 0);
            }
        }

        group._ignoreMove = false;

        setTimeout(function () {
            //If we have only <= one child left then that marker will be shown on the map so don't remove it!
            var stillThereChildCount = 0;
            for (i = childMarkers.length - 1; i >= 0; i--) {
                m = childMarkers[i];
                if (m._spiderLeg) {
                    stillThereChildCount++;
                }
            }


            for (i = childMarkers.length - 1; i >= 0; i--) {
                m = childMarkers[i];

                if (!m._spiderLeg) { //Has already been unspiderfied
                    continue;
                }


                if (m.setOpacity) {
                    m.setOpacity(1);
                    m.setZIndexOffset(0);
                }

                if (stillThereChildCount > 1) {
                    fg.removeLayer(m);
                }

                map.removeLayer(m._spiderLeg);
                delete m._spiderLeg;
            }
            group._animationEnd();
        }, 200);
    }
});


L.MarkerClusterGroup.include({
    //The MarkerCluster currently spiderfied (if any)
    _spiderfied: null,

    _spiderfierOnAdd: function () {
        this._map.on('click', this._unspiderfyWrapper, this);

        if (this._map.options.zoomAnimation) {
            this._map.on('zoomstart', this._unspiderfyZoomStart, this);
        }
        //Browsers without zoomAnimation or a big zoom don't fire zoomstart
        this._map.on('zoomend', this._noanimationUnspiderfy, this);

        if (!L.Browser.touch) {
            this._map.getRenderer(this);
            //Needs to happen in the pageload, not after, or animations don't work in webkit
            //  http://stackoverflow.com/questions/8455200/svg-animate-with-dynamically-added-elements
            //Disable on touch browsers as the animation messes up on a touch zoom and isn't very noticable
        }
    },

    _spiderfierOnRemove: function () {
        this._map.off('click', this._unspiderfyWrapper, this);
        this._map.off('zoomstart', this._unspiderfyZoomStart, this);
        this._map.off('zoomanim', this._unspiderfyZoomAnim, this);

        this._unspiderfy(); //Ensure that markers are back where they should be
    },


    //On zoom start we add a zoomanim handler so that we are guaranteed to be last (after markers are animated)
    //This means we can define the animation they do rather than Markers doing an animation to their actual location
    _unspiderfyZoomStart: function () {
        if (!this._map) { //May have been removed from the map by a zoomEnd handler
            return;
        }

        this._map.on('zoomanim', this._unspiderfyZoomAnim, this);
    },
    _unspiderfyZoomAnim: function (zoomDetails) {
        //Wait until the first zoomanim after the user has finished touch-zooming before running the animation
        if (L.DomUtil.hasClass(this._map._mapPane, 'leaflet-touching')) {
            return;
        }

        this._map.off('zoomanim', this._unspiderfyZoomAnim, this);
        this._unspiderfy(zoomDetails);
    },


    _unspiderfyWrapper: function () {
        /// <summary>_unspiderfy but passes no arguments</summary>
        this._unspiderfy();
    },

    _unspiderfy: function (zoomDetails) {
        if (this._spiderfied) {
            this._spiderfied.unspiderfy(zoomDetails);
        }
    },

    _noanimationUnspiderfy: function () {
        if (this._spiderfied) {
            this._spiderfied._noanimationUnspiderfy();
        }
    },

    //If the given layer is currently being spiderfied then we unspiderfy it so it isn't on the map anymore etc
    _unspiderfyLayer: function (layer) {
        if (layer._spiderLeg) {
            this._featureGroup.removeLayer(layer);

            layer.setOpacity(1);
            //Position will be fixed up immediately in _animationUnspiderfy
            layer.setZIndexOffset(0);

            this._map.removeLayer(layer._spiderLeg);
            delete layer._spiderLeg;
        }
    }
});


}(window, document));