/// <summary>
/// Generates all the tiles at the level specified for a given region of the world.
/// </summary>
/// <param name="level">
/// Base level of zoom.
/// </param>
/// <param name="boundary">
/// Bounding coordinates of the region.
/// </param>
/// <remarks>
/// This API should be used only for a sparse region of the world.
/// The overhead involved in computing the relevant tiles is negligible for a sparse region.
/// </remarks>
public void BuildLevel(int level, Boundary boundary)
{
if (boundary == null)
{
throw new ArgumentNullException("boundary");
}
Trace.TraceInformation("{0}: Building image at level {1}..", DateTime.Now.TimeOfDay.ToString(@"hh\:mm\:ss", CultureInfo.InvariantCulture), level);
CurrentLevel = level;
if (this.tileCreator.ProjectionType == ProjectionTypes.Toast)
{
this.toastProjectionCoordinates = ToastHelper.ComputeTileCoordinates(boundary, level);
Parallel.ForEach(
this.toastProjectionCoordinates[level],
this.ParallelOptions,
tile =>
{
this.tileCreator.Create(level, tile.X, tile.Y);
Interlocked.Increment(ref this.tilesProcessed);
this.ParallelOptions.CancellationToken.ThrowIfCancellationRequested();
});
}
else
{
int tileXMin = Helper.GetMercatorXTileFromLongitude(boundary.Left, level);
int tileXMax = Helper.GetMercatorXTileFromLongitude(boundary.Right, level);
int tileYMin = Helper.GetMercatorYTileFromLatitude(boundary.Bottom, level);
int tileYMax = Helper.GetMercatorYTileFromLatitude(boundary.Top, level);
// If both xmin(ymin) and xmax(ymax) are equal,
// the loop should run atleast for ONE time, Hence incrementing the Xmax(Ymax) by 1
tileXMax = (tileXMin == tileXMax) ? tileXMax + 1 : tileXMax;
tileYMax = (tileYMin == tileYMax) ? tileYMax + 1 : tileYMax;
tileXMax = (int)Math.Min(tileXMax + 1, Math.Pow(2, level));
tileYMax = (int)Math.Min(tileYMax + 1, Math.Pow(2, level));
Parallel.For(
tileYMin,
tileYMax,
this.ParallelOptions,
y =>
{
for (int x = tileXMin; x < tileXMax; x++)
{
this.tileCreator.Create(level, x, y);
Interlocked.Increment(ref this.tilesProcessed);
this.ParallelOptions.CancellationToken.ThrowIfCancellationRequested();
}
});
}
}
/// <summary>
/// Fills up the pyramid of tiles above the specified level.
/// </summary>
/// <param name="level">
/// Base level of zoom.
/// </param>
/// <param name="boundary">
/// Bounding coordinates of the region.
/// </param>
public void BuildParentLevels(int level, Boundary boundary)
{
if (boundary == null)
{
throw new ArgumentNullException("boundary");
}
if (this.tileCreator.ProjectionType == ProjectionTypes.Toast)
{
this.toastProjectionCoordinates = ToastHelper.ComputeTileCoordinates(boundary, level);
foreach (int k in Enumerable.Range(1, level).Select(i => level - i))
{
Trace.TraceInformation("{0}: Filling up pyramid at level {1}..", DateTime.Now.TimeOfDay.ToString(@"hh\:mm\:ss", CultureInfo.InvariantCulture), k);
CurrentLevel = k;
Parallel.ForEach(
this.toastProjectionCoordinates[k],
this.ParallelOptions,
tile =>
{
this.tileCreator.CreateParent(k, tile.X, tile.Y);
Interlocked.Increment(ref this.tilesProcessed);
this.ParallelOptions.CancellationToken.ThrowIfCancellationRequested();
});
}
}
else
{
int tileXMin, tileXMax, tileYMin, tileYMax;
foreach (int k in Enumerable.Range(1, level).Select(i => level - i))
{
CurrentLevel = k;
tileXMin = Helper.GetMercatorXTileFromLongitude(boundary.Left, k);
tileXMax = Helper.GetMercatorXTileFromLongitude(boundary.Right, k);
tileYMin = Helper.GetMercatorYTileFromLatitude(boundary.Bottom, k);
tileYMax = Helper.GetMercatorYTileFromLatitude(boundary.Top, k);
BuildParentLevels(k, tileXMin, tileXMax, tileYMin, tileYMax);
}
}
}