[Geotiff] More problems

[Kieron Flynn]

Hi All,

Well, worked out the things I need to put in to create a custom datum (I
think!) with kind help from Frank Warmerdam.
However I've got a strange one, I pass the following array in to the libtiff
library,

unsigned short GeoKeyDirectory[] =
  {
   1,      1, 2, 15,     // 1 - version 1, revision 1.2,  3 keys defined
   GTModelTypeGeoKey,  0, 1, ModelTypeProjected,
   GTRasterTypeGeoKey,  0, 1, RasterPixelIsArea,
   GTCitationGeoKey,  TIFFTAG_GEOASCIIPARAMS, 20, 0,
   GeographicTypeGeoKey, 0, 1, 32767,    // User_Defined
   GeogGeodeticDatumGeoKey,0, 1, 32767,    // User_Defined
   GeogPrimeMeridianGeoKey,0, 1, PM_Greenwich,  // We shall assume this,
don't know how to find otherwise....
   GeogLinearUnitsGeoKey, 0, 1, Linear_Meter,  // GeogLinearUnitsGeoKey,
Linear_Meter
   GeogAngularUnitsGeoKey, 0, 1, Angular_Degree,  // GeogAngularUnitsGeoKey,
Angular_Degree
   GeogEllipsoidGeoKey, 0, 1, 32767,    // User_Defined
   GeogSemiMajorAxisGeoKey,TIFFTAG_GEODOUBLEPARAMS, 1, 6,
   GeogInvFlatteningGeoKey,TIFFTAG_GEODOUBLEPARAMS, 1, 7,
   ProjectedCSTypeGeoKey, 0, 1, 32767,    // User_Defined
   ProjectionGeoKey,  0, 1, 32767,    // User_Defined
   ProjCoordTransGeoKey, 0, 1, CT_TransverseMercator,
   ProjLinearUnitsGeoKey, 0, 1, Linear_Meter,
   ProjNatOriginLongGeoKey,TIFFTAG_GEODOUBLEPARAMS, 1, 0,
   ProjNatOriginLatGeoKey, TIFFTAG_GEODOUBLEPARAMS, 1, 1,
   ProjCenterEastingGeoKey,TIFFTAG_GEODOUBLEPARAMS, 1, 2,
   ProjCenterNorthingGeoKey,TIFFTAG_GEODOUBLEPARAMS, 1, 3,
   ProjScaleAtNatOriginGeoKey,TIFFTAG_GEODOUBLEPARAMS, 1, 4,
 //  ProjStdParallel1GeoKey,TIFFTAG_GEODOUBLEPARAMS,  1, 5,
   0,0,0,0
  };

  TiffError = TIFFSetField( m_pTiff, TIFFTAG_GEOKEYDIRECTORY, sizeof(
GeoKeyDirectory ), GeoKeyDirectory );
  ok &= TestTiffError( TiffError, _T("TIFFTAG_GEOKEYDIRECTORY") );


which returns saying it detected no error. But there seems to be some kind
of size constraint as the fields :

    ProjNatOriginLongGeoKey,TIFFTAG_GEODOUBLEPARAMS, 1, 0,
   ProjNatOriginLatGeoKey, TIFFTAG_GEODOUBLEPARAMS, 1, 1,
   ProjCenterEastingGeoKey,TIFFTAG_GEODOUBLEPARAMS, 1, 2,
   ProjCenterNorthingGeoKey,TIFFTAG_GEODOUBLEPARAMS, 1, 3,
   ProjScaleAtNatOriginGeoKey,TIFFTAG_GEODOUBLEPARAMS, 1, 4,

are not there when I do a tiff dump. If I move things around, i.e. by having
all the GEODOUBLEPARAMS entries together by moving GeogSemiMajorAxisGeoKey &
GeogInvFlatteningGeoKey to the bottom, it gets as far as
ProjCenterEastingGeoKey, two more further along than it did before!??

Has anybody come across this before. Can I split the array into two smaller
chunks and pass in one after the other, or does it have to go in as one
chunk?

Kieron



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