[gdal-dev] Issue with OGRGeometryFactory::createFromGML

[Even Rouault]

Ian,

this is clearly a bug in OGR that just returns after parsing the first 
<pos> element. I've filed it as the following ticket : 
http://trac.osgeo.org/gdal/ticket/3244
The fix should follow soon.

Best regards,
Even

Durkan, Ian a écrit :
>
> Greetings,
>
> I’m trying to use OGRGeometryFactory::createFromGML and 
> OGRGeometry::exportToWkt (both in ogr_geometry.h) to convert GML 
> geometry elements into well-known text and running into a problem when 
> the GML geometry is provided as a collection of <pos> elements. Note 
> that the geometry is in GML 3.1.1 format, except the capitalization of 
> the outermost element names, which is irrelevant judging by the OGR 
> source code.
>
> This is basically the sequence of calls I’m making, where gmlText is 
> an std::string & contains the input text and buffer is a char* with 
> sufficient space for the output:
>
> OGRGeometry* geom = 
> OGRGeometryFactory::createFromGML(gmlText_noversion.c_str());
>
> geom->exportToWkt(&buffer);
>
> As an example of how things are going wrong, here’s sample input text 
> to createFromGML where a collection of <pos> elements is used:
>
> <p1:polygon xmlns:p1="http://foo" xmlns:p2="http://www.opengis.net/gml">
>
> <p2:exterior>
>
> <p2:LinearRing>
>
> <p2:pos>-39 77.5</p2:pos>
>
> <p2:pos>-38.75 77.75</p2:pos>
>
> <p2:pos>-38.5 77.75</p2:pos>
>
> <p2:pos>-38.25 77.5</p2:pos>
>
> <p2:pos>-38.25 77.25</p2:pos>
>
> <p2:pos>-38.5 77</p2:pos>
>
> <p2:pos>-38.75 77</p2:pos>
>
> <p2:pos>-39 77.25</p2:pos>
>
> <p2:pos>-39 77.5</p2:pos>
>
> </p2:LinearRing>
>
> </p2:exterior>
>
> <p2:interior>
>
> <p2:LinearRing>
>
> <p2:pos>-38.75 77.5</p2:pos>
>
> <p2:pos>-38.5 77.5</p2:pos>
>
> <p2:pos>-38.5 77.25</p2:pos>
>
> <p2:pos>-38.75 77.25</p2:pos>
>
> <p2:pos>-38.75 77.5</p2:pos>
>
> </p2:LinearRing>
>
> </p2:interior>
>
> </p1:polygon>
>
> Given the OGRGeometry created from the above text, exportToWkt gives 
> me the following:
>
> POLYGON ((-39.0 77.5),(-38.75 77.5))
>
> On the other hand, if I pass the following input to createFromGML:
>
> <p1:polygon xmlns:p1="http://foo" xmlns:p2="http://www.opengis.net/gml">
>
> <p2:exterior>
>
> <p2:LinearRing>
>
> <p2:posList>-39 77.5 -38.75 77.75 -38.5 77.75 -38.25 77.5 -38.25 77.25 
> -38.5 77 -38.75 77 -39 77.25 -39 77.5</p2:posList>
>
> </p2:LinearRing>
>
> </p2:exterior>
>
> <p2:interior>
>
> <p2:LinearRing>
>
> <p2:posList>-38.75 77.5 -38.5 77.5 -38.5 77.25 -38.75 77.25 -38.75 
> 77.5</p2:posList>
>
> </p2:LinearRing>
>
> </p2:interior>
>
> </p1:polygon>
>
> ...I get the expected output from exportToWkt:
>
> POLYGON ((-39.0 77.5,-38.75 77.75,-38.5 77.75,-38.25 77.5,-38.25 
> 77.25,-38.5 77.0,-38.75 77.0,-39.0 77.25,-39.0 77.5),(-38.75 
> 77.5,-38.5 77.5,-38.5 77.25,-38.75 77.25,-38.75 77.5))
>
> This is happening for other GML geometries such as LineString as 
> well-the OGR functions handle <posList> input correctly, but not 
> collections of <pos> elements.
>
> Can anyone offer insight as to what is going wrong in the <pos> 
> element collection case? My understanding is that either 4 or more 
> <pos> elements may be used in a LinearRing, or one <posList> 
> containing the list of coordinates.
>
> Ian Durkan ( ian.durkan <at> progeny.net )
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev