Le mercredi 27 janvier 2016 14:01:42, Ari Jolma a écrit : > 27.01.2016, 14:34, Ari Jolma kirjoitti: > > 27.01.2016, 13:27, Even Rouault kirjoitti: > >> Le mercredi 27 janvier 2016 11:55:01, Ari Jolma a écrit : > >>> Folks, > >>> > >>> I'd like to try to implement the XYZM support since I have some free > >>> time. > >>> > >>> Before making a RFC, there are some thoughts/questions/ideas: > >>> > >>> * I made a fork for this work at https://github.com/ajolma/GDAL-XYZM so > >>> I can more easily use travis. > >>> > >>> * I think this is mainly changes in the geometry API and generic > >>> methods. > >>> > >>> Are there other drivers than shape, which are affected? > >> > >> On top of my head: PostGIS, FileGDB, OpenFileGDB, GeoPackage, > >> Spatialite. > >> Probably other RDMBs too (Oracle, MSSQL, ... ?) > > > > I'm not so sure that it is so many. For example PostGIS driver is > > mostly moving WKB back and forth. > > Well, it seems that they are affected. There is for example the > setCoordinateDimension() method, which is called by many drivers and > once measures are supported it becomes ambiguous since coordinate > dimension is 3 for both XYM and XYZ.
I think we should perhaps keep setCoordinateDimension() with the current semantics for legacy reasons but not accept using 3 for XYM or extending it to 4 for XYZM The OGRGeometry class could have for example a setCoordinateInterpretation() with an enum XY, XYZ, XYM and XYZM. And a similar member variable to store it. ... or, as currently getGeometryType() dynamically builds the geometry type, perhaps have instead a wkbGeometryType member in OGRGeometry itself. And have a setGeometryType() to modify it, with restrictions on which kind of geometry type changes are allowed. You can't do point.SetGeometryType(wkbLineString) ) Actually instead of setGeometryType() , the way QGIS has done with its QgsAbstractGeometryV2 class, ie with explicit addZValues( double zInitValue ), addZValues( double zInitValue ), dropZValues(), dropMValues() could be a good inspiration. > > Ari > > > Anyway, I'll look into the geometry API first. > > > > Ari -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
