public static int GTIFKeyGet(GTIF gtif, geokey_t thekey, out ellipsoid_t val, int index, int count)
{
// ignore count
val = 0;
ushort[] vals;
if (GTIFKeyGet(gtif, thekey, out vals, index, 1) == 0)
{
return(0);
}
val = (ellipsoid_t)vals[0];
return(1);
}
//**********************************************************************
// GTIFGetDatumInfo()
//
// Fetch the ellipsoid, and name for a datum.
//**********************************************************************
public static bool GTIFGetDatumInfo(geodeticdatum_t datumCode, out string name, out ellipsoid_t ellipsoid)
{
name=null;
ellipsoid=(ellipsoid_t)KvUserDefined;
// --------------------------------------------------------------------
// Handle a few built-in datums.
// --------------------------------------------------------------------
if(datumCode==geodeticdatum_t.Datum_North_American_Datum_1927)
{
ellipsoid=ellipsoid_t.Ellipse_Clarke_1866;
name="North American Datum 1927";
}
else if(datumCode==geodeticdatum_t.Datum_North_American_Datum_1983)
{
ellipsoid=ellipsoid_t.Ellipse_GRS_1980;
name="North American Datum 1983";
}
else if(datumCode==geodeticdatum_t.Datum_WGS84)
{
ellipsoid=ellipsoid_t.Ellipse_WGS_84;
name="World Geodetic System 1984";
}
else if(datumCode==geodeticdatum_t.Datum_WGS72)
{
ellipsoid=(ellipsoid_t)7043; // WGS7
name="World Geodetic System 1972";
}
if(name!=null) return true;
string pszFilename=CSVFilename("datum.csv");
// --------------------------------------------------------------------
// If we can't find datum.csv then gdal_datum.csv is an
// acceptable fallback. Mostly this is for GDAL.
// --------------------------------------------------------------------
if(!File.Exists(pszFilename))
if(File.Exists(CSVFilename("gdal_datum.csv")))
pszFilename=CSVFilename("gdal_datum.csv");
// --------------------------------------------------------------------
// Search the database for the corresponding datum code.
// --------------------------------------------------------------------
ellipsoid=(ellipsoid_t)atoi(CSVGetField(pszFilename, "DATUM_CODE", ((int)datumCode).ToString(),
CSVCompareCriteria.CC_Integer, "ELLIPSOID_CODE"));
// --------------------------------------------------------------------
// Get the name
// --------------------------------------------------------------------
name=CSVGetField(pszFilename, "DATUM_CODE", ((int)datumCode).ToString(),
CSVCompareCriteria.CC_Integer, "DATUM_NAME");
return true;
}
//**********************************************************************
// GTIFGetEllipsoidInfo()
//
// Fetch info about an ellipsoid. Axes are always returned in
// meters. SemiMajor computed based on inverse flattening
// where that is provided.
//**********************************************************************
public static bool GTIFGetEllipsoidInfo(ellipsoid_t ellipseCode, out string name, out double semiMajor,
out double semiMinor)
{
// --------------------------------------------------------------------
// Try some well known ellipsoids.
// --------------------------------------------------------------------
name=null;
semiMajor=0.0;
semiMinor=0.0;
double invFlattening=0;
if(ellipseCode==ellipsoid_t.Ellipse_Clarke_1866)
{
name="Clarke 1866";
semiMajor=6378206.4;
semiMinor=6356583.8;
invFlattening=0.0;
}
else if(ellipseCode==ellipsoid_t.Ellipse_GRS_1980)
{
name="GRS 1980";
semiMajor=6378137.0;
semiMinor=0.0;
invFlattening=298.257222101;
}
else if(ellipseCode==ellipsoid_t.Ellipse_WGS_84)
{
name="WGS 84";
semiMajor=6378137.0;
semiMinor=0.0;
invFlattening=298.257223563;
}
else if(ellipseCode==(ellipsoid_t)7043)
{
name="WGS 72";
semiMajor=6378135.0;
semiMinor=0.0;
invFlattening=298.26;
}
if(name!=null)
{
if(semiMinor==0.0) semiMinor=semiMajor*(1-1.0/invFlattening);
return true;
}
// --------------------------------------------------------------------
// Get the semi major axis.
// --------------------------------------------------------------------
semiMajor=GTIFAtof(CSVGetField(CSVFilename("ellipsoid.csv"), "ELLIPSOID_CODE",
((int)ellipseCode).ToString(), CSVCompareCriteria.CC_Integer, "SEMI_MAJOR_AXIS"));
double toMeters=1.0;
// --------------------------------------------------------------------
// Get the translation factor into meters.
// --------------------------------------------------------------------
geounits_t UOMLength=(geounits_t)atoi(CSVGetField(CSVFilename("ellipsoid.csv"), "ELLIPSOID_CODE",
((int)ellipseCode).ToString(), CSVCompareCriteria.CC_Integer, "UOM_CODE"));
string dummy;
GTIFGetUOMLengthInfo(UOMLength, out dummy, out toMeters);
semiMajor*=toMeters;
// --------------------------------------------------------------------
// Get the semi-minor. If the Semi-minor axis
// isn't available, compute it based on the inverse flattening.
// --------------------------------------------------------------------
semiMinor=GTIFAtof(CSVGetField(CSVFilename("ellipsoid.csv"), "ELLIPSOID_CODE",
((int)ellipseCode).ToString(), CSVCompareCriteria.CC_Integer, "SEMI_MINOR_AXIS"))*toMeters;
if(semiMinor==0.0)
{
invFlattening=GTIFAtof(CSVGetField(CSVFilename("ellipsoid.csv"), "ELLIPSOID_CODE",
((int)ellipseCode).ToString(), CSVCompareCriteria.CC_Integer, "INV_FLATTENING"));
semiMinor=semiMajor*(1-1.0/invFlattening);
}
// --------------------------------------------------------------------
// Get the name.
// --------------------------------------------------------------------
name=CSVGetField(CSVFilename("ellipsoid.csv"), "ELLIPSOID_CODE", ((int)ellipseCode).ToString(),
CSVCompareCriteria.CC_Integer, "ELLIPSOID_NAME");
return true;
}
public static bool GTIFKeySet(GTIF gtif, geokey_t keyID, ellipsoid_t val)
{
ushort[] val1 = new ushort[] { (ushort)val };
return(GTIFKeySet(gtif, keyID, val1));
}
public static int GTIFKeyGet(GTIF gtif, geokey_t thekey, out ellipsoid_t val, int index)
{
return(GTIFKeyGet(gtif, thekey, out val, index, 0));
}
public static bool GTIFKeySet(GTIF gtif, geokey_t keyID, ellipsoid_t val)
{
ushort[] val1=new ushort[] { (ushort)val };
return GTIFKeySet(gtif, keyID, val1);
}
public static int GTIFKeyGet(GTIF gtif, geokey_t thekey, out ellipsoid_t val, int index)
{
return GTIFKeyGet(gtif, thekey, out val, index, 0);
}
public static int GTIFKeyGet(GTIF gtif, geokey_t thekey, out ellipsoid_t val, int index, int count)
{
// ignore count
val=0;
ushort[] vals;
if(GTIFKeyGet(gtif, thekey, out vals, index, 1)==0) return 0;
val=(ellipsoid_t)vals[0];
return 1;
}
