/// <summary>
/// Get tile envelope in WGS-84 coordinates
/// </summary>
/// <param name="x">x index</param>
/// <param name="y">y index</param>
/// <param name="zoom">zoom</param>
/// <returns>Envelope in WGS-84</returns>
private static Envelope GetTileEnvelope(int x, int y, int zoom)
{
var currTopLeftPixXY = TileCalculator.TileXYToTopLeftPixelXY(x, y);
var currTopLeftCoord = TileCalculator.PixelXYToLatLong((int)currTopLeftPixXY.X, (int)currTopLeftPixXY.Y, zoom);
var currBtmRightPixXY = TileCalculator.TileXYToBottomRightPixelXY(x, y);
var currBtmRightCoord = TileCalculator.PixelXYToLatLong((int)currBtmRightPixXY.X, (int)currBtmRightPixXY.Y, zoom);
return(new Envelope(currTopLeftCoord, currBtmRightCoord));
}
/// <summary>
///
/// </summary>
/// <param name="envelope"></param>
/// <param name="bounds"></param>
/// <returns></returns>
public Tile[,] GetTiles(Envelope envelope, Rectangle bounds)
{
Coordinate mapTopLeft = envelope.TopLeft();
Coordinate mapBottomRight = envelope.BottomRight();
//Clip the coordinates so they are in the range of the web mercator projection
mapTopLeft.Y = TileCalculator.Clip(mapTopLeft.Y, TileCalculator.MinLatitude, TileCalculator.MaxLatitude);
mapTopLeft.X = TileCalculator.Clip(mapTopLeft.X, TileCalculator.MinLongitude, TileCalculator.MaxLongitude);
mapBottomRight.Y = TileCalculator.Clip(mapBottomRight.Y, TileCalculator.MinLatitude, TileCalculator.MaxLatitude);
mapBottomRight.X = TileCalculator.Clip(mapBottomRight.X, TileCalculator.MinLongitude, TileCalculator.MaxLongitude);
int zoom = TileCalculator.DetermineZoomLevel(envelope, bounds);
Point topLeftTileXY = TileCalculator.LatLongToTileXY(mapTopLeft, zoom);
Point btmRightTileXY = TileCalculator.LatLongToTileXY(mapBottomRight, zoom);
var tileMatrix = new Tile[(int)(btmRightTileXY.X - topLeftTileXY.X) + 1, (int)(btmRightTileXY.Y - topLeftTileXY.Y) + 1];
Parallel.For((int)topLeftTileXY.Y, (int)btmRightTileXY.Y + 1,
y => Parallel.For((int)topLeftTileXY.X, (int)btmRightTileXY.X + 1,
x =>
{
var currTopLeftPixXY = TileCalculator.TileXYToTopLeftPixelXY(x, y);
var currTopLeftCoord = TileCalculator.PixelXYToLatLong((int)currTopLeftPixXY.X,
(int)currTopLeftPixXY.Y, zoom);
var currBtmRightPixXY = TileCalculator.TileXYToBottomRightPixelXY(x,
y);
var currBtmRightCoord = TileCalculator.PixelXYToLatLong((int)currBtmRightPixXY.X,
(int)currBtmRightPixXY.Y, zoom);
var currEnv = new Envelope(currTopLeftCoord, currBtmRightCoord);
var tile = GetTile(x, y, currEnv, zoom);
tileMatrix[x - (int)topLeftTileXY.X, y - (int)topLeftTileXY.Y] = tile;
}
));
return(tileMatrix);
}
