private async Task CalculatePointClusters(List <System.Windows.Point> pixels)
#endif
{
int maxX = (int)Math.Ceiling(_map.ActualWidth + ClusterRadius);
int maxY = (int)Math.Ceiling(_map.ActualHeight + ClusterRadius);
clusters = await Task.Run <ClusteredPoint[]>(() =>
{
var clusteredData = new List <ClusteredPoint>();
if (_items != null && _items.Count > 0)
{
double tileZoomRatio = 256 * Math.Pow(2, _currentZoomLevel);
#if WINDOWS_APP || WINDOWS_PHONE_APP
Windows.Foundation.Point pixel;
#elif WPF || WINDOWS_PHONE
System.Windows.Point pixel;
#endif
//Itirate through the data
for (int i = 0; i < _items.Count; i++)
{
var entity = _items[i];
pixel = pixels[i];
if (pixel.X < -ClusterRadius)
{
pixel.X += tileZoomRatio;
}
else if (pixel.X > maxX + ClusterRadius)
{
pixel.X -= tileZoomRatio;
}
//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 >= -ClusterRadius && pixel.Y >= -ClusterRadius)
{
var cluster = (from c in clusteredData
where (pixel.Y >= c.Top && pixel.Y <= c.Bottom &&
((c.Left <= c.Right && pixel.X >= c.Left && pixel.X <= c.Right) ||
(c.Left >= c.Right && (pixel.X >= c.Left || pixel.X <= c.Right))))
select c).FirstOrDefault();
//If entity is not in a cluster then it does not fit an existing cluster
if (cluster == null)//!IsInCluster)
{
cluster = new ClusteredPoint()
{
Location = _allLocations[i],
Left = pixel.X - ClusterRadius,
Right = pixel.X + ClusterRadius,
Top = pixel.Y - ClusterRadius,
Bottom = pixel.Y + ClusterRadius,
Zoom = _currentZoomLevel,
ItemIndices = new List <int>()
{
i
}
};
if (cluster.Left < 0)
{
cluster.Left += tileZoomRatio;
}
if (cluster.Right > tileZoomRatio)
{
cluster.Right -= tileZoomRatio;
}
clusteredData.Add(cluster);
}
else
{
cluster.ItemIndices.Add(i);
}
}
}
}
return(clusteredData.ToArray());
});
}
private async Task CalculateGridClusters(List <System.Windows.Point> pixels, System.Windows.Point centerPixel)
#endif
{
int gridSize = ClusterRadius * 2;
int numXCells = (int)Math.Ceiling(_map.ActualWidth / gridSize);
int numYCells = (int)Math.Ceiling(_map.ActualHeight / gridSize);
int maxX = (int)Math.Ceiling(_map.ActualWidth + ClusterRadius);
int maxY = (int)Math.Ceiling(_map.ActualHeight + ClusterRadius);
//grid should be relative to 0,0 (lat,lon), not top-left corner of map, so that panning
//doesn't cause items to move to different clusters and therefore cluster markers move
//if placement is GridCenter
var gridBaseX = centerPixel.X % gridSize;
var gridBaseY = centerPixel.Y % gridSize;
clusters = await Task.Run <ClusteredPoint[]>(() =>
{
int numCells = numXCells *numYCells;
ClusteredPoint[] clusteredData = new ClusteredPoint[numCells];
#if WINDOWS_APP || WINDOWS_PHONE_APP
Windows.Foundation.Point pixel;
#elif WPF || WINDOWS_PHONE
System.Windows.Point pixel;
#endif
int k, j, key;
//Itirate through the data
for (int i = 0; i < _items.Count; i++)
{
var entity = _items[i];
pixel = pixels[i];
//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 >= -ClusterRadius && pixel.Y >= -ClusterRadius)
{
//calculate the grid position on the map of where the location is located
k = (int)Math.Floor((pixel.X - gridBaseX) / gridSize);
j = (int)Math.Floor((pixel.Y - gridBaseY) / 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 = _allLocations[i],
ItemIndices = new List <int>()
{
i
},
Zoom = _currentZoomLevel,
Left = k *gridSize,
Top = j *gridSize,
Bottom = (j + 1) * gridSize,
Right = (k + 1) * gridSize
};
}
else
{
clusteredData[key].ItemIndices.Add(i);
}
}
}
}
return(clusteredData);
});
}
