public virtual void LatitudeToPixelYTest()
{
foreach (int tileSize in TILE_SIZES)
{
for (sbyte zoomLevel = ZOOM_LEVEL_MIN; zoomLevel <= ZOOM_LEVEL_MAX; ++zoomLevel)
{
long mapSize = MercatorProjection.GetMapSize(zoomLevel, tileSize);
double pixelY = MercatorProjection.LatitudeToPixelY(MercatorProjection.LATITUDE_MAX, mapSize);
Assert.AreEqual(0, pixelY, 0);
pixelY = MercatorProjection.LatitudeToPixelYWithScaleFactor(MercatorProjection.LATITUDE_MAX, MercatorProjection.ZoomLevelToScaleFactor(zoomLevel), tileSize);
Assert.AreEqual(0, pixelY, 0);
pixelY = MercatorProjection.LatitudeToPixelY(0, mapSize);
Assert.AreEqual((float)mapSize / 2, pixelY, 0);
pixelY = MercatorProjection.LatitudeToPixelYWithScaleFactor(0, MercatorProjection.ZoomLevelToScaleFactor(zoomLevel), tileSize);
Assert.AreEqual((float)mapSize / 2, pixelY, 0);
pixelY = MercatorProjection.LatitudeToPixelY(MercatorProjection.LATITUDE_MIN, mapSize);
Assert.AreEqual(mapSize, pixelY, 0);
pixelY = MercatorProjection.LatitudeToPixelYWithScaleFactor(MercatorProjection.LATITUDE_MIN, MercatorProjection.ZoomLevelToScaleFactor(zoomLevel), tileSize);
Assert.AreEqual(mapSize, pixelY, 0);
}
}
}
/// <summary>
/// Calculates the absolute pixel position for a zoom level and tile size relative to origin
/// </summary>
/// <param name="latLong"> </param>
/// <param name="mapSize"> precomputed size of map. </param>
/// <returns> the relative pixel position to the origin values (e.g. for a tile) </returns>
public static Point GetPixelRelative(LatLong latLong, long mapSize, double x, double y)
{
double pixelX = MercatorProjection.LongitudeToPixelX(latLong.Longitude, mapSize) - x;
double pixelY = MercatorProjection.LatitudeToPixelY(latLong.Latitude, mapSize) - y;
return(new Point(pixelX, pixelY));
}
/// <summary>
/// Calculates the zoom level that allows to display the <seealso cref="BoundingBox"/> on a view with the <seealso cref="Dimension"/> and
/// tile size.
/// </summary>
/// <param name="dimension">
/// the <seealso cref="Dimension"/> of the view. </param>
/// <param name="boundingBox">
/// the <seealso cref="BoundingBox"/> to display. </param>
/// <param name="tileSize">
/// the size of the tiles. </param>
/// <returns> the zoom level that allows to display the <seealso cref="BoundingBox"/> on a view with the <seealso cref="Dimension"/> and
/// tile size. </returns>
public static sbyte ZoomForBounds(Dimension dimension, BoundingBox boundingBox, int tileSize)
{
long mapSize = MercatorProjection.GetMapSize((sbyte)0, tileSize);
double pixelXMax = MercatorProjection.LongitudeToPixelX(boundingBox.MaxLongitude, mapSize);
double pixelXMin = MercatorProjection.LongitudeToPixelX(boundingBox.MinLongitude, mapSize);
double zoomX = -Math.Log(Math.Abs(pixelXMax - pixelXMin) / dimension.Width) / Math.Log(2);
double pixelYMax = MercatorProjection.LatitudeToPixelY(boundingBox.MaxLatitude, mapSize);
double pixelYMin = MercatorProjection.LatitudeToPixelY(boundingBox.MinLatitude, mapSize);
double zoomY = -Math.Log(Math.Abs(pixelYMax - pixelYMin) / dimension.Height) / Math.Log(2);
double zoom = Math.Floor(Math.Min(zoomX, zoomY));
if (zoom < 0)
{
return(0);
}
if (zoom > sbyte.MaxValue)
{
return(sbyte.MaxValue);
}
return((sbyte)zoom);
}
