[Proj] Search directory for grid shift files
marco.hugentobler at sourcepole.ch
Thu Nov 7 11:22:08 EST 2013
Thank you for the advice. The PROJ_LIB variable seems to be set at least
on windows, so that's already a good thing to check.
>One suggestion, in the QGIS context might be that you keep them in
some sort of QGIS subtree, and use pj_set_searchpath() to check there
Does the pj_set_searchpath add an additional search path or does it also
override the default path? If it adds, having a dedicated subdirectory
On 07.11.2013 16:27, Frank Warmerdam wrote:
> PROJ is not really setup to make this available, and it is complicated
> by the fact that there are several search rules. With PROJ 4.8 you
> could sort of accomplish this by setting a custom file open function
> on the context and then seeing where gets probed for but that is ugly
> and it is hard to know which of the probe locations is ideal. It also
> would only work for this very recent version.
> In some situations the PROJ_LIB environment variable may be set, and
> you could use that.
> Just checking for the "usual places" such as /usr/share/proj or
> /usr/local/share/proj on unix systems might go quite a long ways.
> One suggestion, in the QGIS context might be that you keep them in
> some sort of QGIS subtree, and use pj_set_searchpath() to check
> there. The downside of this approach is that other applications on
> the systems (including things run as subprocesses of QGIS) won't see
> the files.
> Best regards,
> On Thu, Nov 7, 2013 at 1:55 AM, Marco Hugentobler
> <marco.hugentobler at sourcepole.ch
> <mailto:marco.hugentobler at sourcepole.ch>> wrote:
> I'm trying to implement support for datum transformations with
> grid shift files into the QGIS gui. For better useability, I would
> like to check if a shift file for a datum transformation is
> present (and if not, give a hint to the user where to put the .gsb
> Is there a way to find out the search directory for grid shift
> files? I see in the API doc there is a method pj_set_searchpath,
> however I cannot find one to read the path. What is the best
> approach to get the search path?
> Thank you for any hint,
> Proj mailing list
> Proj at lists.maptools.org <mailto:Proj at lists.maptools.org>
> I set the clouds in motion - turn up | Frank Warmerdam,
> warmerdam at pobox.com <mailto:warmerdam at pobox.com>
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush | Geospatial Software Developer
> Proj mailing list
> Proj at lists.maptools.org
Dr. Marco Hugentobler
Sourcepole - Linux & Open Source Solutions
Weberstrasse 5, CH-8004 Zürich, Switzerland
marco.hugentobler at sourcepole.ch http://www.sourcepole.ch
Technical Advisor QGIS Project Steering Committee
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Proj