private void Page_Load(object sender, EventArgs e)
{
try
{
// get param
ParamVector param = new ParamVector(Request);
// check if raster is available
UrlVisitor urlVisitor = new UrlVisitor();
urlVisitor.VisitServers(Config.raster_servers, 0, "RasterService/bing_tile_exist.aspx" + Request.Url.Query);
if (urlVisitor.isSuccess && urlVisitor.isTextResult && urlVisitor.textResult.Trim() == "0")
{
// when raster is not available at this location, return fully transparent tile
OutputImage(Config.fully_transparent_256_tile, true);
}
else
{
// when anything goes wrong, just return regular vector tile
GenerateVectorTile(param);
}
}
catch (Exception ex)
{
OutputError("Internal error: " + ex.Message);
}
}
private void Page_Load(object sender, EventArgs e)
{
try
{
// get parameters
ParamVector param = new ParamVector(Request);
GenerateVectorTile(param);
}
catch (Exception ex)
{
OutputError("Internal error: " + ex.Message);
}
}
protected void GenerateVectorTile(ParamVector param)
{
// check max level
if (param.z > Config.vector_max_level)
{
OutputError("Requested tile is beyond max level");
return;
}
// layers will be rendered in groups
// group requests will be sent to multiple servers in turns: the first group goes to the first server, the second goes to the second, and so on
UrlVisitor urlVisitor = new UrlVisitor();
PngImage img = new PngImage(param.styleset.tileWidth, param.styleset.tileHeight, param.styleset.bgColor);
// get group queryStrings
string[] queryStrings = param.GetQueryStringsByRenderGroup();
long totalResponseTime = 0;
for (int i = 0; i < queryStrings.Length; i++)
{
if (queryStrings[i] == "")
{
continue;
}
int serverVisited = urlVisitor.VisitServers(Config.vector_servers, i % Config.vector_servers.Length, queryStrings[i]);
if (urlVisitor.isSuccess)
{
if (urlVisitor.isImageResult)
{
Statistics.LayerGroupRequested(urlVisitor.responseTime, serverVisited);
totalResponseTime += urlVisitor.responseTime;
img.Add(urlVisitor.imageResult);
}
else
{
OutputError("Remote error: remote server returns text where image is expected: " + urlVisitor.textResult);
return;
}
}
else
{
OutputError("Remote error: " + urlVisitor.errMessage);
return;
}
}
// merge images into one
OutputImage(img.Save(), true);
Statistics.TileRequested(totalResponseTime, param.z);
}