Coordinate transformation of geometries between CRSs with different axis ordering (C API)
Florian Katerndahl via gdal-dev <[email protected]>
| Newsgroups | gmane.comp.gis.gdal.devel |
|---|---|
| Message-ID | <[email protected]> |
Dear all, I'm currently working on a small program which allows users to specify vector inputs in different coordinates systems and that potentially "normalizes" them to EPSG:4326 internally to process them further. Maybe I'm too inexperienced and there's an easy solution but I got hung up on the coordinate transformation when the input CRS has a different axis ordering compared to the output CRS using GDAL's/OGR's C API. For example, transforming between EPSG:5556 and EPSG:4326, GDAL outputs a warning (forwarded from proj?) that the output's latitude is invalid. Setting the axis ordering of the target CRS to `OAMS_TRADITIONAL_GIS_ORDER` fixes this and results in correctly located polygons. My question is now: Is it sufficient/correct to compare the axis ordering of the input and output coordinate systems and set above mentioned flag (or a custom mapping when neither "x"/"y" are the first two axis) in case they differ? Kind regards and many thanks in advance, Florian Katerndahl