[geotk] Pseudocylindrical projections

[Martin Desruisseaux]

Hello Jon

Le 10/06/13 16:54, Jon Blower a écrit :
> Does Geotoolkit support pseudocylindrical projections (Robinson, Mollweide etc)?  One of our users has a use case for generating map imagery in one of these projections via WMS.

Unfortunately not yet. A workaround exists, but may be uneasy... It 
should be possible to use Proj.4 together with Geotk. However this has 
never been tested, and may require some adjustment in the Geotk code. 
Possible inconvenient is that using Proj.4 requires installation of a 
native library, and Proj.4 does not support (to my knowledge) map 
projection derivatives. Map projection derivatives are used for more 
accurate calculations of Envelope and faster raster reprojections, 
however Geotk code should still be capable to work in the absence of 
those derivatives.

I plan to test more extensively the "Java code" + "Proj.4" cohabitation 
in Apache SIS, where Proj.4 could be used as a fallback for projections 
not yet available in Java. This will hopefully be made easier by the use 
of a "dependency injection" framework in replacement of 
"org.geotoolkit.factory". The hope is to have the referencing module 
ported to SIS before the Frascati OGC meeting in September. In the main 
time, if the user feel adventurous, (s)he may try to install Proj.4 
version 4.8 or above, checkout GeoAPI (http://www.geoapi.org/) from SVN, 
then try to build it with the following command:

mvn install -DskipNativeLibraryTests=false

The next steps would depend on whether the above worked well or not.

     Regards,
     Martin