private void SetRenderTransform()
{
var tileScale = (double)(1 << TileGrid.ZoomLevel);
var scale = Math.Pow(2d, parentMap.ZoomLevel) / tileScale;
var tileCenter = new Point(tileScale * (0.5 + parentMap.Center.Longitude / 360d),
tileScale * (0.5 - WebMercatorProjection.LatitudeToY(parentMap.Center.Latitude) / 360d));
var tileOrigin = new Point(MapProjection.TileSize * (tileCenter.X - TileGrid.XMin),
MapProjection.TileSize * (tileCenter.Y - TileGrid.YMin));
var viewCenter = new Point(parentMap.RenderSize.Width / 2d, parentMap.RenderSize.Height / 2d);
((MatrixTransform)RenderTransform).Matrix =
MapProjection.CreateTransformMatrix(tileOrigin, scale, parentMap.Heading, viewCenter);
}
private void SetRenderTransform()
{
var tileScale = (double)(1 << TileGrid.ZoomLevel);
var scale = Math.Pow(2d, parentMap.ZoomLevel) / tileScale;
var tileCenterX = tileScale * (0.5 + parentMap.Center.Longitude / 360d);
var tileCenterY = tileScale * (0.5 - WebMercatorProjection.LatitudeToY(parentMap.Center.Latitude) / 360d);
var tileOriginX = MapProjection.TileSize * (tileCenterX - TileGrid.XMin);
var tileOriginY = MapProjection.TileSize * (tileCenterY - TileGrid.YMin);
var viewCenterX = parentMap.RenderSize.Width / 2d;
var viewCenterY = parentMap.RenderSize.Height / 2d;
((MatrixTransform)RenderTransform).Matrix = MatrixEx.TranslateScaleRotateTranslate(
-tileOriginX, -tileOriginY, scale, scale, parentMap.Heading, viewCenterX, viewCenterY);
}
private string GetLatLonBoundingBoxUri(int x, int y, int zoomLevel)
{
var tileSize = 360d / (1 << zoomLevel); // tile width in degrees
var west = x * tileSize - 180d;
var east = (x + 1) * tileSize - 180d;
var south = WebMercatorProjection.YToLatitude(180d - (y + 1) * tileSize);
var north = WebMercatorProjection.YToLatitude(180d - y * tileSize);
return(uriFormat
.Replace("{w}", west.ToString(CultureInfo.InvariantCulture))
.Replace("{s}", south.ToString(CultureInfo.InvariantCulture))
.Replace("{e}", east.ToString(CultureInfo.InvariantCulture))
.Replace("{n}", north.ToString(CultureInfo.InvariantCulture)));
}
private TileGrid GetTileGrid()
{
var tileZoomLevel = Math.Max(0, (int)Math.Round(parentMap.ZoomLevel + ZoomLevelOffset));
var tileScale = (double)(1 << tileZoomLevel);
var scale = tileScale / (Math.Pow(2d, parentMap.ZoomLevel) * MapProjection.TileSize);
var tileCenter = new Point(tileScale * (0.5 + parentMap.Center.Longitude / 360d),
tileScale * (0.5 - WebMercatorProjection.LatitudeToY(parentMap.Center.Latitude) / 360d));
var viewCenter = new Point(parentMap.RenderSize.Width / 2d, parentMap.RenderSize.Height / 2d);
var transform = new MatrixTransform
{
Matrix = MapProjection.CreateTransformMatrix(viewCenter, scale, -parentMap.Heading, tileCenter)
};
var bounds = transform.TransformBounds(new Rect(0d, 0d, parentMap.RenderSize.Width, parentMap.RenderSize.Height));
return(new TileGrid(tileZoomLevel,
(int)Math.Floor(bounds.X), (int)Math.Floor(bounds.Y),
(int)Math.Floor(bounds.X + bounds.Width), (int)Math.Floor(bounds.Y + bounds.Height)));
}
/// <summary>
/// see https://en.wikipedia.org/wiki/Rhumb_line
/// </summary>
public static LocationCollection CalculateRhumbLineLocations(this Location location1, Location location2, double resolution = 1d)
{
if (resolution <= 0d)
{
throw new ArgumentOutOfRangeException("The parameter resolution must be greater than zero.");
}
var y1 = WebMercatorProjection.LatitudeToY(location1.Latitude);
if (double.IsInfinity(y1))
{
throw new ArgumentOutOfRangeException("The parameter location1 must have an absolute latitude value of less than 90 degrees.");
}
var y2 = WebMercatorProjection.LatitudeToY(location2.Latitude);
if (double.IsInfinity(y2))
{
throw new ArgumentOutOfRangeException("The parameter location2 must have an absolute latitude value of less than 90 degrees.");
}
var x1 = location1.Longitude;
var x2 = location2.Longitude;
var dx = x2 - x1;
var dy = y2 - y1;
var s = Math.Sqrt(dx * dx + dy * dy);
var n = (int)Math.Ceiling(s / resolution);
var locations = new LocationCollection(new Location(location1.Latitude, location1.Longitude));
for (int i = 1; i < n; i++)
{
double x = x1 + i * dx / n;
double y = y1 + i * dy / n;
locations.Add(WebMercatorProjection.YToLatitude(y), x);
}
locations.Add(location2.Latitude, location2.Longitude);
return(locations);
}
public MapBase()
{
MapProjection = new WebMercatorProjection();
ScaleRotateTransform.Children.Add(ScaleTransform);
ScaleRotateTransform.Children.Add(RotateTransform);
// set Background by Style to enable resetting by ClearValue in MapLayerPropertyChanged
var style = new Style(typeof(MapBase));
style.Setters.Add(new Setter(BackgroundProperty, new SolidColorBrush(Colors.Transparent)));
Style = style;
Clip = new RectangleGeometry();
SizeChanged += (s, e) =>
{
Clip.Rect = new Rect(0d, 0d, e.NewSize.Width, e.NewSize.Height);
ResetTransformCenter();
UpdateTransform();
};
}
public MapBase()
{
MapProjection = new WebMercatorProjection();
ScaleRotateTransform.Children.Add(ScaleTransform);
ScaleRotateTransform.Children.Add(RotateTransform);
}
/// <summary>
/// Calculates a series of Locations on a rhumb line, or loxodrome, that connects the two specified Locations,
/// with an optional angular resolution specified in degrees.
///
/// See https://en.wikipedia.org/wiki/Rhumb_line
/// </summary>
public static LocationCollection LoxodromeLocations(Location location1, Location location2, double resolution = 1d)
{
if (resolution <= 0d)
{
throw new ArgumentOutOfRangeException(
nameof(resolution), "The resolution argument must be greater than zero.");
}
var lat1 = location1.Latitude;
var lon1 = location1.Longitude;
var lat2 = location2.Latitude;
var lon2 = location2.Longitude;
var y1 = WebMercatorProjection.LatitudeToY(lat1);
var y2 = WebMercatorProjection.LatitudeToY(lat2);
if (double.IsInfinity(y1))
{
throw new ArgumentOutOfRangeException(
nameof(location1), "The location1 argument must have an absolute latitude value of less than 90.");
}
if (double.IsInfinity(y2))
{
throw new ArgumentOutOfRangeException(
nameof(location2), "The location2 argument must have an absolute latitude value of less than 90.");
}
var dlat = lat2 - lat1;
var dlon = lon2 - lon1;
var dy = y2 - y1;
// beta = atan(dlon,dy)
// sec(beta) = 1 / cos(atan(dlon,dy)) = sqrt(1 + (dlon/dy)^2)
var sec = Math.Sqrt(1d + dlon * dlon / (dy * dy));
const double secLimit = 1000d; // beta approximately +/-90°
double s12;
if (sec > secLimit)
{
var lat = (lat1 + lat2) * Math.PI / 360d; // mean latitude
s12 = Math.Abs(dlon * Math.Cos(lat)); // distance in degrees along parallel of latitude
}
else
{
s12 = Math.Abs(dlat * sec); // distance in degrees along loxodrome
}
var n = (int)Math.Ceiling(s12 / resolution);
var locations = new LocationCollection(new Location(lat1, lon1));
if (sec > secLimit)
{
for (var i = 1; i < n; i++)
{
var lon = lon1 + i * dlon / n;
var lat = WebMercatorProjection.YToLatitude(y1 + i * dy / n);
locations.Add(lat, lon);
}
}
else
{
for (var i = 1; i < n; i++)
{
var lat = lat1 + i * dlat / n;
var lon = lon1 + dlon * (WebMercatorProjection.LatitudeToY(lat) - y1) / dy;
locations.Add(lat, lon);
}
}
locations.Add(lat2, lon2);
return(locations);
}
