Do you mean a MultiLineString? This piece of code is working for me (I hope without any bug).
if (wkbFlatten(poGeometry->getGeometryType()) == wkbMultiLineString) multiLineStringGeometry(poGeometry); ... multiLineStringGeometry(OGRGeometry* poGeometry) { OGRMultiLineString* multiLine = dynamic_cast<OGRMultiLineString*>(poGeometry); int numGeometries = multiLine->getNumGeometries(); for (int i = 0; i < numGeometries; i++) { OGRGeometry* eachGeometry = multiLine->getGeometryRef(i); OGRLineString* line = dynamic_cast<OGRLineString*>(eachGeometry); // do whatever with that LineString } } On Mon, 16 Oct 2023 at 12:14, Roland Baviere via gdal-dev < gdal-dev@lists.osgeo.org> wrote: > Hi all, > > I hope this e-mel finds you well. > > I am trying to read a shapefile layer from OGR from a C++ application > following the tutorial found here: > https://gdal.org/tutorials/vector_api_tut.html#reading-from-ogr > > We have difficulties with a layer containing PolyLines with several parts. > > The pre-existing code works fine for polylines having a unique part. > > Do you have any example or advice to help me implement a version that > works for polylines containing several parts. My intention is to display > each shape on a map, so I need to retrieve the coordinates of points and > draw segment between points when relevant. > > Thanks a lot for your help. > > Kind regards, > > Roland > > > > //// CODE THAT WORKS for "simple" polylines but fails when dealiing with a > polyline containing several parts > > int o = 0; > for(auto y : poGeometry->toLineString()) { > if (o == 0) { > line.mInCoord = QGeoCoordinate(y.getX(), > y.getY()); > } else if (o == > (poGeometry->toLineString()->getNumPoints() - 1)) { > line.mOutCoord = QGeoCoordinate(y.getX(), > y.getY()); > } else { > > line.mPath.addCoordinate(QGeoCoordinate(y.getX(), y.getY())); > } > qDebug() << o; > o++; > } > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/gdal-dev >
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