Hi,
- merging the underlying API without any format support is I believe of
little interest. So I'll wait for at least one format (likely
GeoPackage) to have merged in the master of their specification an
official way of storing the coordinate epoch. I've also prepared an
enhancement of the GeoTIFF spec regarding this
(https://github.com/opengeospatial/geotiff/pull/99) that will likely be
discussed at the next OGC GeoTIFF SWG meeting.
- I've just chatted with Howard and a good compromise could be that for
formats that will have an official way of storing the coordinate epoch,
we store it by default (when it is set), and for formats that we
unilaterally extend (GML, KML, GeoJSON, etc.), we require an explicit
GDAL_ENABLE_COORD_EPOCH_STORAGE=YES configuration option to be set
(default would be NO). We might revisit in the future the default value.
- On the vector side of things, things will probably get more
complicated for some drivers, as it is likely that Spatialite (see
https://groups.google.com/g/spatialite-users/c/NtbuBpRzYBE) or PostGIS
might have per-geometry coordinate epoch, not at the layer level. But I
don't think that would invalidate having support for it at the layer
level (those database already support a per-geometry CRS, but GDAL
support for that is probably lacking a bit in those drivers), as a
OGRGeometry can potentially be associated with its own
OGRSpatialReference object.
Even
Le 27/05/2021 à 15:01, Howard Butler a écrit :
On May 26, 2021, at 8:33 PM, Nyall Dawson <[email protected]> wrote:
Can I make the suggestion that a subset of
https://github.com/OSGeo/gdal/pull/3827 could be created and be merged
on its own? Specifically the commits which add the underlying API for
GDAL to handle epochs should be controversy-free and suitable for
merge outside of the larger/trickier question of patching in support
to the data formats.
:thumbsup:
As for the patching of data formats with GDAL application-specific metadata, as
I said, I don't have a better option, but I'm satisfied if the process of
writing epochs into metadata is opt-in (some kind of global CRS option? we
already have magic switches like that).
Howard
--
http://www.spatialys.com
My software is free, but my time generally not.
_______________________________________________
gdal-dev mailing list
[email protected]
https://lists.osgeo.org/mailman/listinfo/gdal-dev
