[Gdal-dev] Problems retrieving z-values

[tjansson]

> Could you provide some snippet of your code + ideally a piece of data?

> As I see, we don't have any tests of 25D geometries for S-57 so I'm

> interested in updating the test suite accordingly.




A part of the code traverses thourgh all layers and extract each feature...


while((poFeature = poLayer->GetNextFeature()) != NULL)


...with appurtenant feature definition...


poFDefn = poLayer->GetLayerDefn()


...and geometry...


poGeometry = poFeature->GetGeometryRef()


These properties - feature, feature definition and geometry - are passed as
parameters to a parser function...


parseGeometry(..., poGeometry, poFDefn, poFeature, ...);


In the parserGeometry function there the geometry type is retieved...


OGRwkbGeometryType geometryType = poFDefn->GetGeomType();


...and a switch is used to check what type is it...



switch(geometryType)

{

...

case wkbPoint:

poPoint = (OGRPoint *) poGeometry;

double dX = poPoint->getX();

double dY = poPoint->getY();

...

case wkbPoint25D:

poPoint = (OGRPoint *) poGeometry;

double dX = poPoint->getX();

double dY = poPoint->getY();

double dY = poPoint->getZ();

...

}


I the switch have cases for all the different geometry types - wkbUnknown,
wkbPoint, wkbLineString, wkbPolygon, wkbMultiPoint, wkbMultiLineString,
wkbMultiPolygon, wkbGeometryCollection, wkbNone, wkbLinearRing, wkbPoint25D,
wkbLineString25D, wkbPolygon25D, wkbMultiPoint25D, wkbMultiLineString25D, 
wkbMultiPolygon25D, wkbGeometryCollection25D - but, as stated before, the
code never hits on any of the 2.5D types cases.


The maps I am user are downloaded from NOAA (
http://chartmaker.ncd.noaa.gov/mcd/enc/download.htm
http://chartmaker.ncd.noaa.gov/mcd/enc/download.htm).  One map I have used
is one called  http://www.nabble.com/file/p12916176/US2AK91M.000
US2AK91M.000 . This is converter into a simple dat-file (
http://www.nabble.com/file/p12916176/s57output.dat s57output.dat )
containing XYZ-data. The Z-data has until now, always been 0 (zero), but the
XY-data are ok as far as I can tell.


http://www.nabble.com/file/p12916176/US2AK91M_000_pic.jpg 

Above is an image drawn with GNUPlot from dat-file generated by the code.


Don't know if this helps in identifying the problem.




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