/// <summary> /// A callback method that is used to generate a pushpin for a cluster of entities. /// </summary> /// <param name="cluster">A clustered point.</param> /// <returns>A pushpin that represents the clustered entities.</returns> public abstract ColoredPushpin RenderCluster(ClusteredPoint cluster);
private void Cluster(int zoom)
{
BackgroundWorker worker = new BackgroundWorker();
worker.WorkerSupportsCancellation = true;
worker.DoWork += (s, a) =>
{
_zoomLocked[zoom] = true;
if (_clusteredData[zoom] == null)
{
_clusteredData[zoom] = new List <ClusteredPoint>();
}
if (_entities != null && _entities.Count > 0)
{
double tileZoomRatio = 256 * Math.Pow(2, zoom);
Point pixel;
bool IsInCluster;
//Itirate through the data
foreach (var entity in _entities)
{
IsInCluster = false;
pixel = Helpers.CalculateGlobalPixel(entity.Location, tileZoomRatio);
foreach (var cluster in _clusteredData[zoom])
{
//See if pixel fits into any existing clusters
if (pixel.Y >= cluster.Top && pixel.Y <= cluster.Bottom &&
((cluster.Left <= cluster.Right && pixel.X >= cluster.Left && pixel.X <= cluster.Right) ||
(cluster.Left >= cluster.Right && (pixel.X >= cluster.Left || pixel.X <= cluster.Right))))
{
cluster.EntityIds.Add(entity.ID);
IsInCluster = true;
break;
}
}
//If entity is not in a cluster then it does not fit an existing cluster
if (!IsInCluster)
{
ClusteredPoint cluster = new ClusteredPoint();
cluster.Location = entity.Location;
cluster.Left = pixel.X - _options.ClusterRadius;
cluster.Right = pixel.X + _options.ClusterRadius;
cluster.Top = pixel.Y - _options.ClusterRadius;
cluster.Bottom = pixel.Y + _options.ClusterRadius;
cluster.Zoom = zoom;
cluster.EntityIds = new List <int>()
{
entity.ID
};
if (cluster.Left < 0)
{
cluster.Left += tileZoomRatio;
}
if (cluster.Right > tileZoomRatio)
{
cluster.Right -= tileZoomRatio;
}
_clusteredData[zoom].Add(cluster);
}
}
}
};
worker.RunWorkerCompleted += (s, a) =>
{
_zoomLocked[zoom] = false;
Render();
};
worker.RunWorkerAsync();
}
private void Cluster()
{
int zoom = (int)Math.Round(_map.ZoomLevel);
if (_worker == null)
{
_worker = new BackgroundWorker();
_worker.WorkerSupportsCancellation = true;
_worker.DoWork += (s, a) =>
{
if (_entities != null && _entities.Count > 0)
{
int gridSize = _options.ClusterRadius * 2;
int numXCells = (int)Math.Ceiling(_map.ViewportSize.Width / gridSize);
int numYCells = (int)Math.Ceiling(_map.ViewportSize.Height / gridSize);
int numCells = numXCells * numYCells;
ClusteredPoint[] clusteredData = new ClusteredPoint[numCells];
Point pixel;
int k, j, key;
int maxX = (int)Math.Ceiling(_map.ViewportSize.Width + _options.ClusterRadius);
int maxY = (int)Math.Ceiling(_map.ViewportSize.Height + _options.ClusterRadius);
//Itirate through the data
foreach (var entity in _entities)
{
if (_worker.CancellationPending)
{
a.Cancel = true;
break;
}
pixel = _map.LocationToViewportPoint(entity.Location);
//Check to see if the pin is within the bounds of the viewable map
if (pixel != null && pixel.X <= maxX && pixel.Y <= maxY && pixel.X >= -_options.ClusterRadius && pixel.Y >= -_options.ClusterRadius)
{
//calculate the grid position on the map of where the location is located
k = (int)Math.Floor(pixel.X / gridSize);
j = (int)Math.Floor(pixel.Y / gridSize);
//calculates the grid location in the array
key = k + j * numXCells;
if (key >= 0 && key < numCells)
{
if (clusteredData[key] == null)
{
clusteredData[key] = new ClusteredPoint()
{
Location = entity.Location,
EntityIds = new List <int>()
{
entity.ID
},
Zoom = zoom
};
}
else
{
clusteredData[key].EntityIds.Add(entity.ID);
}
}
}
}
if (!a.Cancel)
{
a.Result = clusteredData.ToList();
}
}
};
_worker.RunWorkerCompleted += (s, a) =>
{
if (!a.Cancelled)
{
if (a.Result != null)
{
Render(a.Result as List <ClusteredPoint>);
}
else
{
Render(null);
}
}
else
{
_worker.RunWorkerAsync();
}
};
}
if (_worker != null && _worker.IsBusy && _worker.WorkerSupportsCancellation)
{
_worker.CancelAsync();
}
else
{
_worker.RunWorkerAsync();
}
}