libproj: fix longtitude estimation for PJ_AREA #2476
Merged
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PROJ likes to have longitudes in the range [-180, 180] which causes problems with geometries crossing the anti-meridian at either -180 or 180, also with the PROJ-specific PJ_AREA object required by PROJ to select the correct PROJ pipeline(s).
Tests with areas crossing the antimeridian and reprojecting these to UTM zone 60 or UTM zone 1 were successful. However, reprojecting back to a latlong location does not work out of the box. The user has to manually add the PROJ
+over
switch to the transformation pipeline, e.g.to successfully reproject an area back from UTM zone 1 to latlong: round trip latlong - > UTM zone -> latlong.
Unfortunately, there is no straightforward way (also not in the PROJ API) to automatically inject the
+over
switch at the correct place(s) in a PROJ projection pipeline.