private DEMFileSource ParseGDALSource(XmlReader reader)
{
DEMFileSource source = new DEMFileSource();
try
{
source.Type = reader.Name;
int depth = reader.Depth;
while (reader.Read())
{
if (reader.Depth == depth)
{
break;
}
if (reader.NodeType == XmlNodeType.Element)
{
//<xs:element name="SourceFilename" type="SourceFilenameType"/>
//<xs:element name="OpenOptions" type="OpenOptionsType"/>
//<xs:element name="SourceBand" type="xs:string"/> <!-- should be refined into xs:nonNegativeInteger or mask,xs:nonNegativeInteger -->
//<xs:element name="SourceProperties" type="SourcePropertiesType"/>
//<xs:element name="SrcRect" type="RectType"/>
//<xs:element name="DstRect" type="RectType"/>
switch (reader.Name)
{
case "SourceFilename":
if (reader.HasAttributes)
{
while (reader.MoveToNextAttribute())
{
switch (reader.Name)
{
case "relativeToVRT":
reader.ReadAttributeValue();
source.IsPathRelative = reader.Value == "1";
break;
}
}
reader.MoveToElement();
}
source.SourceFileName = reader.ReadElementContentAsString();
break;
case "DstRect":
//<DstRect xOff="249600" yOff="8400" xSize="1201" ySize="1201" />
if (reader.HasAttributes)
{
while (reader.MoveToNextAttribute())
{
switch (reader.Name)
{
case "xOff":
reader.ReadAttributeValue();
source.DstxOff = int.Parse(reader.Value);
break;
case "yOff":
reader.ReadAttributeValue();
source.DstyOff = int.Parse(reader.Value);
break;
case "xSize":
reader.ReadAttributeValue();
source.DstxSize = int.Parse(reader.Value);
break;
case "ySize":
reader.ReadAttributeValue();
source.DstySize = int.Parse(reader.Value);
break;
}
}
reader.MoveToElement();
}
break;
case "NODATA":
source.NoData = reader.ReadElementContentAsDouble();
break;
default:
source.Properties[reader.Name] = reader.ReadElementContentAsString();
break;
}
}
}
}
catch (Exception ex)
{
_logger?.LogError($"Error parsing GDAL source: {ex.Message}");
}
return(source);
}
private IEnumerable <DEMFileSource> GetSources(DEMDataSet dataSet, string vrtFileName)
{
Uri localVrtUri = new Uri(Path.GetFullPath(vrtFileName), UriKind.Absolute);
Uri remoteVrtUri = new Uri(dataSet.DataSource.IndexFilePath, UriKind.Absolute);
double[] geoTransform;
var registration = dataSet.FileFormat.Registration;
Dictionary <string, string> properties;
// Create an XmlReader
using (FileStream fileStream = new FileStream(vrtFileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
using (XmlReader reader = XmlReader.Create(fileStream))
{
if (reader.ReadToFollowing("GeoTransform"))
{
geoTransform = ParseGeoTransform(reader.ReadElementContentAsString());
}
else
{
throw new Exception("GeoTransform element not found!");
}
string sourceName = "";
if (reader.ReadToFollowing("VRTRasterBand"))
{
properties = new Dictionary <string, string>();
while (reader.Read())
{
if (reader.NodeType == XmlNodeType.Element)
{
if (reader.Name == "ComplexSource" || reader.Name == "SimpleSource")
{
sourceName = reader.Name;
break;
}
properties[reader.Name] = reader.ReadElementContentAsString();
}
}
bool isOnFirstSource = true;
while (isOnFirstSource || reader.ReadToFollowing(sourceName))
{
DEMFileSource source = ParseGDALSource(reader);
// SetLocalFileName
source.SourceFileNameAbsolute = new Uri(remoteVrtUri, source.SourceFileName).ToString();
source.LocalFileName = new Uri(localVrtUri, source.SourceFileName).LocalPath;
// Transform origin
// Xp = padfTransform[0] + P * padfTransform[1] + L * padfTransform[2];
// Yp = padfTransform[3] + P * padfTransform[4] + L * padfTransform[5];
source.OriginLon = geoTransform[0] + source.DstxOff * geoTransform[1] + source.DstyOff * geoTransform[2];
source.OriginLat = geoTransform[3] + source.DstxOff * geoTransform[4] + source.DstyOff * geoTransform[5];
source.DestLon = geoTransform[0] + (source.DstxOff + source.DstxSize) * geoTransform[1] + (source.DstyOff + source.DstySize) * geoTransform[2];
source.DestLat = geoTransform[3] + (source.DstxOff + source.DstxSize) * geoTransform[4] + (source.DstyOff + source.DstySize) * geoTransform[5];
if (registration == DEMFileRegistrationMode.Grid)
{
source.BBox = new BoundingBox(Math.Round(source.OriginLon + geoTransform[1] / 2, 10),
Math.Round(source.DestLon - +geoTransform[1] / 2, 10),
Math.Round(source.DestLat - geoTransform[5] / 2, 10),
Math.Round(source.OriginLat + geoTransform[5] / 2, 10));
}
else
{
source.OriginLon = Math.Round(source.OriginLon, 10);
source.OriginLat = Math.Round(source.OriginLat, 10);
source.DestLon = Math.Round(source.DestLon, 10);
source.DestLat = Math.Round(source.DestLat, 10);
source.BBox = new BoundingBox(source.OriginLon, source.DestLon, source.DestLat, source.OriginLat);
}
isOnFirstSource = false;
yield return(source);
}
}
}
}