private static TrLibException TR_ErrorToTrLibException(TrLib.TR_Error error)
{
switch (error)
{
case TrLib.TR_Error.TR_LABEL_ERROR:
return(new TrLibException(TrLibException.ErrorTypes.Label, TrLib.TR_GetLastError()));
case TrLib.TR_Error.TR_TRANSFORMATION_ERROR:
return(new TrLibException(TrLibException.ErrorTypes.Transformation, TrLib.TR_GetLastError()));
case TrLib.TR_Error.TR_ALLOCATION_ERROR:
return(new TrLibException(TrLibException.ErrorTypes.Allocation, TrLib.TR_GetLastError()));
default:
throw new ArgumentException($"{error} is not a known TRLIB error");
}
}
public Point Transform(Point from, int toEpsgId)
{
if (!epsgIdToMiniLabelMap.ContainsKey(from.EpsgId))
{
throw new UnsupportedEpsgIdException(from.EpsgId);
}
if (!epsgIdToMiniLabelMap.ContainsKey(toEpsgId))
{
throw new UnsupportedEpsgIdException(toEpsgId);
}
var fromMiniLabel = epsgIdToMiniLabelMap[from.EpsgId];
var toMiniLabel = epsgIdToMiniLabelMap[toEpsgId];
if (fromMiniLabel.StartsWith("geo"))
{
from.X = DegToRad(from.X);
from.Y = DegToRad(from.Y);
}
IntPtr tr = IntPtr.Zero;
TrLib.TR_Error error;
double oX, oY, oZ;
error = TrLib.InitLibrary(geoidsDirectory);
if (error != TrLib.TR_Error.TR_OK)
{
//In some situations TrLib will report a TR_TRANSFORMATION_ERROR on initialization
//even though the library is able to perform transformations just fine.
//Haven't been able to find out what causes the situation, but a workaround is to continue if the error code is zero
var errorCode = TrLib.TR_GetLastError();
if (errorCode != 0)
{
throw new TrLibException(TrLibException.ErrorTypes.Initialization, errorCode);
}
}
tr = TrLib.TR_Open(fromMiniLabel, toMiniLabel, "");
if (tr == IntPtr.Zero)
{
throw new TrLibException(TrLibException.ErrorTypes.Open, TrLib.TR_GetLastError());
}
try
{
TrLib.TR_AllowUnsafeTransformations();
error = TrLib.TR_TransformPoint(tr, from.X, from.Y, from.Z, out oX, out oY, out oZ);
}
finally
{
TrLib.TR_Close(tr);
}
if (error != TrLib.TR_Error.TR_OK)
{
throw TR_ErrorToTrLibException(error);
}
if (toMiniLabel.StartsWith("geo"))
{
oX = RadToDeg(oX);
oY = RadToDeg(oY);
oZ = RadToDeg(oZ);
}
Point to = new Point()
{
X = oX,
Y = oY,
Z = oZ,
EpsgId = toEpsgId
};
return(to);
}