private static int[] GetOrdinateOrder(BoundingBoxAxisOrderInterpretation bbaoi, int[] ordinateOrder)
{
switch (bbaoi)
{
case BoundingBoxAxisOrderInterpretation.Natural:
return(new[] { 0, 1 });
case BoundingBoxAxisOrderInterpretation.Geographic:
return(new[] { 1, 0 });
default:
return(ordinateOrder);
}
}
/// <summary>
/// Method to parse WMTS tile sources from a stream
/// </summary>
/// <param name="source">The source stream</param>
/// <param name="bbaoi">The way how axis order should be interpreted for <ows:BoundingBox>es</param>
/// <returns>An enumeration of tile sources</returns>
public static IEnumerable <ITileSource> Parse(Stream source,
BoundingBoxAxisOrderInterpretation bbaoi = BoundingBoxAxisOrderInterpretation.Natural)
{
var ser = new XmlSerializer(typeof(Capabilities));
Capabilities capabilties;
using (var reader = new StreamReader(source))
capabilties = (Capabilities)ser.Deserialize(reader);
var tileSchemas = GetTileMatrixSets(capabilties.Contents.TileMatrixSet, bbaoi);
var tileSources = GetLayers(capabilties, tileSchemas);
return(tileSources);
}
private static List <ITileSchema> GetTileMatrixSets(IEnumerable <TileMatrixSet> tileMatrixSets,
BoundingBoxAxisOrderInterpretation bbaoi)
{
// Get a set of well known scale sets. For these we don't need to have
var wkss = new WellKnownScaleSets();
// Axis order registry
var crsAxisOrder = new CrsAxisOrderRegistry();
// Unit of measure registry
var crsUnitOfMeasure = new CrsUnitOfMeasureRegistry();
var tileSchemas = new List <ITileSchema>();
foreach (var tileMatrixSet in tileMatrixSets)
{
// Check if a Well-Known scale set is used, either by Identifier or WellKnownScaleSet property
var ss = wkss[tileMatrixSet.Identifier.Value];
if (ss == null && !string.IsNullOrEmpty(tileMatrixSet.WellKnownScaleSet))
{
ss = wkss[tileMatrixSet.WellKnownScaleSet.Split(':').Last()];
}
// Try to parse the Crs
var supportedCrs = tileMatrixSet.SupportedCRS;
// Hack to fix broken crs spec
supportedCrs = supportedCrs.Replace("6.18:3", "6.18.3");
CrsIdentifier crs;
if (!CrsIdentifier.TryParse(supportedCrs, out crs))
{
// If we cannot parse the crs, we cannot compute tile schema, thus ignore.
// ToDo: Log this
continue;
}
// Get the ordinate order for the crs (x, y) or (y, x) aka (lat, long)
var ordinateOrder = crsAxisOrder[crs];
// Get the unit of measure for the crs
var unitOfMeasure = crsUnitOfMeasure[crs];
// Create a new WMTS tile schema
var tileSchema = new WmtsTileSchema();
// Add the resolutions
foreach (var tileMatrix in tileMatrixSet.TileMatrix)
{
tileSchema.Resolutions.Add(ToResolution(tileMatrix, ordinateOrder, unitOfMeasure.ToMeter, ss));
}
tileSchema.Extent = ToExtent(tileMatrixSet, tileSchema, GetOrdinateOrder(bbaoi, ordinateOrder));
// Fill in the remaining properties
tileSchema.Name = tileMatrixSet.Identifier.Value;
tileSchema.YAxis = YAxis.OSM;
tileSchema.Srs = supportedCrs;
tileSchema.SupportedSRS = crs;
// record the tile schema
tileSchemas.Add(tileSchema);
}
return(tileSchemas);
}
