/// <summary> Get a tile cover for the specified bounds and zoom. </summary>
/// <param name="bounds"> Geographic bounding box.</param>
/// <param name="zoom"> Zoom level. </param>
/// <returns> The tile cover set. </returns>
/// <example>
/// Build a map of Colorado using TileCover:
/// <code>
/// var sw = new Vector2d(36.997749, -109.0524961);
/// var ne = new Vector2d(41.0002612, -102.0609668);
/// var coloradoBounds = new Vector2dBounds(sw, ne);
/// var tileCover = TileCover.Get(coloradoBounds, 8);
/// Console.Write("Tiles Needed: " + tileCover.Count);
/// foreach (var id in tileCover)
/// {
/// var tile = new RasterTile();
/// var parameters = new Tile.Parameters();
/// parameters.Id = id;
/// parameters.Fs = MapboxAccess.Instance;
/// parameters.MapId = "mapbox://styles/mapbox/outdoors-v10";
/// tile.Initialize(parameters, (Action)(() =>
/// {
/// // Place tiles and load textures.
/// }));
/// }
/// </code>
/// </example>
public static HashSet <CanonicalTileId> Get(Vector2dBounds bounds, int zoom)
{
var tiles = new HashSet <CanonicalTileId>();
if (bounds.IsEmpty() ||
bounds.South > Constants.LatitudeMax ||
bounds.North < -Constants.LatitudeMax)
{
return(tiles);
}
var hull = Vector2dBounds.FromCoordinates(
new Vector2d(Math.Max(bounds.South, -Constants.LatitudeMax), bounds.West),
new Vector2d(Math.Min(bounds.North, Constants.LatitudeMax), bounds.East));
var sw = CoordinateToTileId(hull.SouthWest, zoom);
var ne = CoordinateToTileId(hull.NorthEast, zoom);
// Scanlines.
for (var x = sw.X; x <= ne.X; ++x)
{
for (var y = ne.Y; y <= sw.Y; ++y)
{
tiles.Add(new UnwrappedTileId(zoom, x, y).Canonical);
}
}
return(tiles);
}
public void Hull()
{
var bounds1 = new Vector2dBounds(new Vector2d(-10, -10), new Vector2d(10, 10));
var bounds2 = Vector2dBounds.FromCoordinates(new Vector2d(10, 10), new Vector2d(-10, -10));
Assert.AreEqual(bounds1.South, bounds2.South);
Assert.AreEqual(bounds1.West, bounds2.West);
Assert.AreEqual(bounds1.North, bounds2.North);
Assert.AreEqual(bounds1.East, bounds2.East);
}