private List <GeoBitmap> GetImageTiles(Matrix matrix)
{
List <GeoBitmap> v_ret = new List <GeoBitmap>();
BoundingBox viewBounds = GetViewBounds(matrix);
double[] hgLog = LogicalToGeoLatLon(viewBounds.XMin, viewBounds.YMax);
double[] bdLog = LogicalToGeoLatLon(viewBounds.XMax, viewBounds.YMin);
BoundingBox viewPortBbox = new BoundingBox(hgLog[0], bdLog[0]
, bdLog[1], hgLog[1]);
BoundingBox bbox = matrix.Transform(_geomBBox);
// Get current zoom level
double mapSizeAtCurrentZoom = 1d * bbox.Width / _geomBBox.Width;
int zoom = 0;
uint size = 0;
while (size <= mapSizeAtCurrentZoom)
{
zoom++;
if (zoom == 24)
{
break;
}
size = BingMapsTileSystem.MapSize(zoom);
}
// At viewport zoom, what tile size is it ?
double tileSizeAtZoom = 256 * mapSizeAtCurrentZoom / size;
Trace.TraceInformation("tileSizeAtZoom: " + tileSizeAtZoom.ToString());
if (tileSizeAtZoom < 256 && !_baseLayer.UseLowResTiles)
{
Trace.TraceWarning("Error in zoom calculation, tile size should be <256 but it is " + tileSizeAtZoom);
}
bool bTakeLowerDef = tileSizeAtZoom < 400;// _baseLayer.UseLowResTiles;
if (bTakeLowerDef)
{
zoom--;
size = BingMapsTileSystem.MapSize(zoom);
}
// Contruct image list
int startX, startY, endX, endY = 0;
int tileStartX, tileStartY, tileEndX, tileEndY = 0;
BingMapsTileSystem.LatLongToPixelXY(viewPortBbox.YMax, viewPortBbox.XMin, zoom, out startX, out startY);
BingMapsTileSystem.LatLongToPixelXY(viewPortBbox.YMin, viewPortBbox.XMax, zoom, out endX, out endY);
BingMapsTileSystem.PixelXYToTileXY(startX, startY, out tileStartX, out tileStartY);
BingMapsTileSystem.PixelXYToTileXY(endX, endY, out tileEndX, out tileEndY);
bool stop = false;
for (int x = tileStartX; x <= tileEndX; x++)
{
for (int y = tileStartY; y <= tileEndY; y++)
{
if (stop)
{
break;
}
//GeoBitmap geoBmp = await _tileDownloader.DownloadTileAsync(zoom, x, y, _baseLayer);
GeoBitmap geoBmp = _tileDownloader.DownloadTile(zoom, x, y, _baseLayer);
stop = geoBmp != null && geoBmp.Exception != null && _baseLayer.StopDownloadBatchIfException;
if (!stop)
{
v_ret.Add(geoBmp);
}
}
if (stop)
{
break;
}
}
return(v_ret);
}
public GeoBitmap DownloadTile(int zoom, int x, int y, IBaseLayer baseLayer)
{
Uri uri = new Uri(baseLayer.GetTileUrl(zoom, x, y));
GeoBitmap geoBmp = new GeoBitmap() { OriginUri = uri.ToString() };
try
{
TileIndex index = new TileIndex(x, y, zoom);
Bitmap tileImg = null;
tileImg = GetTileFromCache(index, baseLayer.Name);
if (tileImg != null)
{
geoBmp.Origin = TileOrigin.Memory;
}
else
{
tileImg = GetTileFromDisc(index, baseLayer.Name);
if (tileImg != null)
{
geoBmp.Origin = TileOrigin.Disk;
SaveTileToCache(tileImg, index, baseLayer.Name);
}
}
if (tileImg == null)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
request.Timeout = 500;
request.UserAgent = USER_AGENT;
//IWebProxy webProxy = WebRequest.DefaultWebProxy;
//webProxy.Credentials = CredentialCache.DefaultNetworkCredentials;
//request.Proxy = webProxy;
try
{
using (WebResponse response = request.GetResponse())
using (Stream stream = response.GetResponseStream())
{
tileImg = (Bitmap)Bitmap.FromStream(stream);
}
}
catch (WebException webEx)
{
Trace.TraceWarning("Unable to download image at " + uri.ToString() + ": " + webEx.Message);
tileImg = new Bitmap(256, 256);
using (Graphics g = Graphics.FromImage(tileImg))
{
g.Clear(Color.LightGray);
g.DrawRectangle(Pens.Red, 0, 0, 255, 255);
g.DrawLine(Pens.Red, 1, 1, 255, 255);
}
geoBmp.Exception = webEx;
}
finally
{
geoBmp.Origin = TileOrigin.Download;
if (geoBmp.Exception == null)
{
SaveTileToDisc(tileImg, index, baseLayer.Name);
SaveTileToCache(tileImg, index, baseLayer.Name);
}
}
}
geoBmp.Bitmap = tileImg;
// what are X,Y coords for images
int xPos, yPos = 0;
double lat, lon = 0;
double lat2, lon2 = 0;
BingMapsTileSystem.TileXYToPixelXY(x, y, out xPos, out yPos);
BingMapsTileSystem.PixelXYToLatLong(xPos, yPos, zoom, out lat, out lon);
BingMapsTileSystem.PixelXYToLatLong(xPos + 256, yPos + 256, zoom, out lat2, out lon2);
geoBmp.BBox = new BoundingBox(lon, lon2, lat2, lat);
geoBmp.Index = new TileIndex(x, y, zoom);
}
catch (Exception ex)
{
geoBmp.Exception = ex;
Trace.TraceWarning("Unable to load base layer at " + uri.ToString() + ": " + ex.Message);
}
return geoBmp;
}
