Hello Florian
Le 30/04/2020 à 09:27, Florian Micklich a écrit :
I assume that my WGS84 point is in lng / lat that's why I use a
special axisConvention (…snip…).
CoordinateReferenceSystem sourceCRS = CRS.forCode("EPSG:4326");
CoordinateReferenceSystem targetCRS = CRS.forCode("EPSG:32632");
CoordinateReferenceSystem alternativCRSsource =
AbstractCRS.castOrCopy(sourceCRS).forConvention(AxesConvention.RIGHT_HANDED);
Just as a note, those 3 lines can be made a little bit simpler. OGC
defines another code, which is similar to "EPSG:4326" but with (lon,lat)
axis order. This is called "CRS:84" and should be understood by many GIS
software, not just SIS. So those 3 lines can be written as below:
CoordinateReferenceSystem sourceCRS = CRS.forCode("CRS:84");
CoordinateReferenceSystem targetCRS = CRS.forCode("EPSG:32632");
Alternatively we also define some frequently used CRS in a CommonCRS
class. So another way to get the same result is:
CoordinateReferenceSystem sourceCRS = CommonCRS.WGS84.normalizedGeographic();
CoordinateReferenceSystem targetCRS = CRS.forCode("EPSG:32632");
Javadoc:
https://sis.apache.org/apidocs/org/apache/sis/referencing/CommonCRS.html
(…snip…) I am wondering off the org.opengis.* packades and why I have
to cast the op object result from
|org.opengis.geometry.|DirectPosition|; to
org.apache.sis.geometry.DirectPosition2D;
|
It is not necessary to cast actually. The cast was done only for
convenience, for direct access to the x and y fields. But the following
code work as well:
DirectPosition2D sisPoint = new DirectPosition2D(8.4036527, 49.0068901);
DirectPosition projPoint = op.getMathTransform().transform(sisPoint, null);
double x = projPoint.getOrdinate(0);
double y = projPoint.getOrdinate(1);
Note that the getOrdinate(int) method may need to be renamed
getCoordinate(int) in a future version of GeoAPI interfaces, for
consistency with terminology used in ISO/OGC standards. In such case the
old method would still be there as a deprecated method.
The apache project I am working on is not allowed to use LGPL and I
know this packages from another geotools project.
Yes the main authors of GeoTools referencing module are now working on
Apache SIS. That is why some classes are similar. A review of
intellectual property has been done in order to port to SIS only the
GeoTools codes that have been written by developers who have signed the
Apache Individual Contributor License Agreement (ICLA), which is the
vast majority of metadata and referencing code. Each of those classes
are listed in the link below, with a list of commits for each class and
actions taken for the few cases where a commit was not done by an author
who signed ICLA:
https://svn.apache.org/repos/asf/sis/ip-review/
So is my example correct?
Yes the code is correct. It can be made a little bit more implementation
neutral if you wish as below:
// SIS-specifie code
CRSAuthorityFactory crsFactory = getAuthorityFactory(null);
// Implementation neutral
GeographicCRS sourceCRS = crsFactory.createGeographicCRS("CRS:84");
ProjectedCRS targetCRS = crsFactory.createProjectedCRS("EPSG:32632");
// SIS-specific code for now (implementation neutral way to be provided in a
future version)
CoordinateOperation op = CRS.findOperation(alternativCRSsource, targetCRS,
null);
Under which license do the org.opengis packages run which are
apparently included in one of the sis dependencies (just to be save in
this part)
GeoAPI 3.0.1 interfaces in the org.opengis packages are under OGC
Software License Version 1.0 which is BSD like:
https://www.ogc.org/ogc/software/1.0
A discussion about this license can be viewed there:
https://github.com/spdx/license-list-XML/issues/845
As discussed in above link, a future version of GeoAPI interfaces may
need to move to a slightly different license, the OGC document license.
No decision has been taken yet and the Apache foundation will be
consulted first. In the context of GeoAPI, the OGC document license is
the same than the current BSD like "OGC software license" with one
additional constraint: if a user wants to modify an interface in the
"org.opengis" package, then (s)he needs to rename "org.opengis" into
something else. After (s)he has done this renaming, the interfaces fall
into the BSD-like license. Note that this is similar to a similar
constraints in Apache license, which said that if we modify an Apache
software then we can not call it Apache anymore; we have to give it a
new name. The "OGC document license" is simply more specific about the
requirement to change the namespace (in the case of Java: package and
module names) in order to avoid conflicts with other implementations of
the standard.
https://www.ogc.org/ogc/document
But this is for future. Current GeoAPI 3.0.1 is BSD-like, and I plan to
have a discussion between OGC and Apache before to eventually move
GeoAPI 3.1/4.0 to "OGC document license" for making sure that it is okay
for Apache.
Martin
