[geos-devel] Problems creating polygons with holes

strk strk at keybit.net
Mon Jun 28 06:28:02 EDT 2004


Can you produce a neter code exploiting the bug ?
I mean a .cpp file I can compile and run and debug :)

-strk;

On Mon, Jun 28, 2004 at 11:05:22AM +0100, Darren Carman wrote:
> defs:
> typedef struct boundaryPt {
>   double x;
>   double y;
> };
> typedef vector<boundaryPt>    boundary;
> typedef vector<boundary>      boundaryList;
> typedef vector<boundaryList>  polygonList;
> 
> class members used:
>   polygonList       ptPolygons;
>   string tmpStr;
>   string errMsg;
> 
> class function:
> string c_polygon_gml::WKTString(void) {
>   TRACE_FUNC("c_polygon_gml::WKTString");
>   vector<Geometry *> polygons;
>   vector<Geometry *> holes;
>   int i,j,k;
>   string resStr = "";
> 
>   try{
>     GeometryFactory *gf=new GeometryFactory(new PrecisionModel(),0);
> 
>     // for each outer ring create a CoordinateList and add all the points to it
>     for(i=0; i< static_cast<int>(ptPolygons.size()); i++) {
>       CoordinateList *cl1=CoordinateListFactory::internalFactory->createCoordinateList();
>       boundaryList bl = ptPolygons[i];
>       boundary b = bl[0];
>       TRACE_OUTPUT("Polygon " << i);
>       for(k=0; k< static_cast<int>(b.size()); k++) {
>         TRACE_OUTPUT("Added point " << b[k].x << ',' << b[k].y);
>         cl1->add(*(new Coordinate(b[k].x,b[k].y)));
>       }
> 
>       // for each hole create a coordinate list like above, create a polygon and add to a Geometry vector
>       for(j=1; j< static_cast<int>(bl.size()); j++) {
>         TRACE_OUTPUT("Hole " << j);
>         boundary b = bl[j];
>         CoordinateList *cl2=CoordinateListFactory::internalFactory->createCoordinateList();
>         for(k=0; k< static_cast<int>(b.size()); k++) {
>           TRACE_OUTPUT("Added point " << b[k].x << ',' << b[k].y);
>           cl2->add(*(new Coordinate(b[k].x,b[k].y)));
>         }
>         TRACE_OUTPUT("Creating polygon for hole " << j << ": " << cl2->toString());
>         Geometry *geom1=gf->createPolygon(gf->createLinearRing(cl2),NULL);
>         TRACE_OUTPUT("Geometry " << j << " : " << geom1->toString());
>         holes.push_back(geom1);
>         delete cl2;
>       }
>       // create a polygon from the 1st CoordinateList and the holes
>       TRACE_OUTPUT("Creating polygon " << i << ": " << cl1->toString());
>       Geometry *geom2=gf->createPolygon(gf->createLinearRing(cl1),&holes);
>       TRACE_OUTPUT("test ");
>       TRACE_OUTPUT("Geometry " << i << " : " << geom2->toString());
> 
>       // save this polygon in another vector
>       TRACE_OUTPUT("Adding polygon " << i);
>       polygons.push_back(geom2);
>       delete cl1;
>     }
>     TRACE_OUTPUT("Creating multi-polygon");
>     // when all done create a MultiPolygon object
>     Geometry *geom3=gf->createMultiPolygon(&polygons);
>     TRACE_OUTPUT("Creating string");
>     resStr = geom3->toString();
> 
>     //clean up
>     delete geom3;
>     delete gf;
>   }
>   catch (GEOSException *ge) {
>     errMsg = ge->toString();
>   }
>   return resStr;
> }
> 
> XML read in by class and stored in ptPolygons:
> <?xml version="1.0" encoding="UTF-8"?>
> <AreaDefinition>
> <GDSRequest>
> <query>
> <AreaQuery outputContent="public">
> <queryArea>
> <Polygon srsName="osgb:BNG">
> <outerBoundaryIs>
> <LinearRing>
> <coordinates>
> 339252,1019302
> 339252,1029077
> 348752,1029077
> 346102,1019653
> 339252,1019302
> </coordinates>
> </LinearRing>
> </outerBoundaryIs>
> <innerBoundaryIs>
> <LinearRing>
> <coordinates>
> 340000,1020000
> 340000,1021000
> 341000,1021000
> 341000,1020000
> 340000,1020000
> </coordinates>
> </LinearRing>
> </innerBoundaryIs>
> </Polygon>
> </queryArea>
> </AreaQuery>
> </query>
> </GDSRequest>
> </AreaDefinition>
> 
> Output:
> TR: TRACE ENTRY:c_polygon_gml::WKTString line 168 file c_polygon_gml.cpp
> TR:   Polygon 0
> TR:   Added point 339252,1.0193e+06
> TR:   Added point 339252,1.02908e+06
> TR:   Added point 348752,1.02908e+06
> TR:   Added point 346102,1.01965e+06
> TR:   Added point 339252,1.0193e+06
> TR:   Hole 1
> TR:   Added point 340000,1.02e+06
> TR:   Added point 340000,1.021e+06
> TR:   Added point 341000,1.021e+06
> TR:   Added point 341000,1.02e+06
> TR:   Added point 340000,1.02e+06
> TR:   Creating polygon for hole 1: (340000,1.02e+06,1.7e-308) (340000,1.021e+06,1.7e-308) (341000,1.021e+06,1.7e-308) (341000,1.02e+06,1.7e-308) (340000,1.02e+06,1.7e-308)
> TR:   Geometry 1 : POLYGON ((340000.0000000000000000 1020000.0000000000000000, 340000.0000000000000000 1021000.0000000000000000, 341000.0000000000000000 1021000.0000000000000000, 341000.0000000000000000 1020000.0000000000000000, 340000.0000000000000000 1020000.0000000000000000))
> TR:   Creating polygon 0: (339252,1.0193e+06,1.7e-308) (339252,1.02908e+06,1.7e-308) (348752,1.02908e+06,1.7e-308) (346102,1.01965e+06,1.7e-308) (339252,1.0193e+06,1.7e-308)
> TR:   test
> Segmentation fault
> 
> Output when the hole is removed:
> TR: TRACE ENTRY:c_polygon_gml::WKTString line 168 file c_polygon_gml.cpp
> TR:   Polygon 0
> TR:   Added point 339252,1.0193e+06
> TR:   Added point 339252,1.02908e+06
> TR:   Added point 348752,1.02908e+06
> TR:   Added point 346102,1.01965e+06
> TR:   Added point 339252,1.0193e+06
> TR:   Creating polygon 0: (339252,1.0193e+06,1.7e-308) (339252,1.02908e+06,1.7e-308) (348752,1.02908e+06,1.7e-308) (346102,1.01965e+06,1.7e-308) (339252,1.0193e+06,1.7e-308)
> TR:   test
> TR:   Geometry 0 : POLYGON ((339252.0000000000000000 1019302.0000000000000000, 339252.0000000000000000 1029077.0000000000000000, 348752.0000000000000000 1029077.0000000000000000, 346102.0000000000000000 1019653.0000000000000000, 339252.0000000000000000 1019302.0000000000000000))
> TR:   Adding polygon 0
> TR:   Creating multi-polygon
> TR:   Creating string
> TR: TRACE EXIT:c_polygon_gml::WKTString
> ERROR:
> WTF format
> MULTIPOLYGON (((339252.0000000000000000 1019302.0000000000000000, 339252.0000000000000000 1029077.0000000000000000, 348752.0000000000000000 1029077.0000000000000000, 346102.0000000000000000 1019653.0000000000000000, 339252.0000000000000000 1019302.0000000000000000)))
> 
> 
> -----Original Message-----
> From: strk [mailto:strk at keybit.net]
> Sent: 28 June 2004 11:01
> To: GEOS Development List
> Subject: Re: [geos-devel] Problems creating polygons with holes
> 
> 
> Can you send the test code ?
> There are currently no known bug ...
> --strk;
> 
> On Mon, Jun 28, 2004 at 10:15:45AM +0100, Darren Carman wrote:
> > Hi all,
> > 
> > I am creating polygons with holes and want to use geos to allow me to output them in WKT.
> > 
> > A polygon without a hole works fine, but as soon as I add a hole I get a segmentation fault after calling the createPolygon function (GeometryFactory) and trying to run toString on that polygon.
> > 
> > I am using version 1.0.
> > 
> > I have tried getting the latest version from CVS but this causes a segmentation fault to occur while adding the 5th polygon coordinate to the CoordinateList (there are only 4 coordinates in the test polygon, the 5th being the first one repeated - I tried making it 6 to see if it was a problem with closing the polygon but I still got a segmentation fault while adding the 5th).
> > 
> > Is there a fix for this, or has anyone come accross it?
> > 
> > Thanks in advance,
> > Darren
> > 
> > 
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