public override List <CKCluster> ClustersInRect(MKMapRect rect, double zoom, Tree.ICKAnnotationTree tree)
{
var zoomSpecificSpan = 100 * this.CellSize / Math.Pow(2, zoom + 8);
var clusters = new List <CKCluster>();
var visited = new Dictionary <CKAnnotation, CKCandidate>();
var annotations = tree.AnnotationsInRect(rect);
foreach (var ann in annotations)
{
if (visited.ContainsKey(ann))
{
continue;
}
var cluster = this.ClusterWithCoordinate(ann.Coordinate);
clusters.Add(cluster);
MKMapRect clusterRect = this.CKCreateRectFromSpan(ann.Coordinate, zoomSpecificSpan);
var neighbors = tree.AnnotationsInRect(clusterRect);
foreach (var neighbor in neighbors)
{
var distance = CKDistance.GetDistance(neighbor.Coordinate, cluster.Coordinate);
CKCandidate candidate;
if (visited.TryGetValue(neighbor, out candidate))
{
if (candidate.Distance < distance)
{
continue;
}
candidate.Cluster.RemoveAnnotation(neighbor);
}
else
{
candidate = new CKCandidate();
visited.Add(neighbor, candidate);
}
candidate.Cluster = cluster;
candidate.Distance = distance;
cluster.AddAnnotation(neighbor);
}
}
return(clusters);
}
public override List <CKCluster> ClustersInRect(MapKit.MKMapRect rect, double zoom, Tree.ICKAnnotationTree tree)
{
var clusters = new Dictionary <double, CKCluster>();
var annotations = tree.AnnotationsInRect(rect);
var numCells = Math.Ceiling(256 * Math.Pow(2, zoom) / this.CellSize);
foreach (var ann in annotations)
{
var point = MKMapPoint.FromCoordinate(ann.Coordinate);
var col = numCells * point.X / MKMapSize.World.Width;
var row = numCells * point.Y / MKMapSize.World.Height;
var key = numCells * row + col;
CKCluster cluster;
if (clusters.ContainsKey(key))
{
cluster = clusters[key];
}
else
{
cluster = this.ClusterWithCoordinate(ann.Coordinate);
clusters[key] = cluster;
}
cluster.AddAnnotation(ann);
}
return(clusters.Values.ToList());
}
