------------------------------------------------------- Ing. Simone Giannecchini GeoSolutions S.A.S. Owner - Software Engineer Via Carignoni 51 55041 Camaiore (LU) Italy
phone: +39 0584983027 fax: +39 0584983027 mob: +39 333 8128928 http://www.geo-solutions.it http://simboss.blogspot.com/ http://www.linkedin.com/in/simonegiannecchini ------------------------------------------------------- On Tue, Jun 9, 2009 at 12:27 PM, Andrea Aime<[email protected]> wrote: > Simone Giannecchini ha scritto: >> I have a few doubts about the update of ReferencedEnvelope. Are you >> sure it is already capable of doing 3D semantic-wise? >> It implementes BoundingBox which is purely 2D and that's why it is >> used almost everywhere in the feature code. If we start to put 3d >> envelopes in it, we would be clearly violating the BoundingBox >> interface or, put it another way, what is going to be the meaning of x >> and y with a 3D crs ( it might seem a naive question and probably is, >> but I am trying to understand which assumptions we are making). > > ReferencedEnvelope extends jts envelope and implements > org.opengis.geometry.Envelope and BoundingBox > > JTS Envelope and BoundingBox are 2 dimensional, > org.opengis.geometry.Envelope is n-dimensional and we implement > the getDimension() and getMimumum(ordinate)/getMaximum(ordinate) > that do allow to grab dimensions above the second. > This is correct of course, but right now this works "semantically" because a ReferencedEnvelope IS a BBox. If we proceed this way, this would not be true anymore, therefore something that until yesterday was 2D would become ND. I understand this might look like a sterile discussion, but I think it is a sensitive topic give the vastity of places where the ReferencedEnvelope is used. > I was thinking that extending the class to n dimensions produces > no harm, whoever is using it as a 2d one just won't notice the > extra dimensions. > > I'm still doubtful about methods that do check relationships > between envelopes thought. What should we do when a nd and > a 2d envelope are compared? Flatten the nd one or return a > marker that the comparison does not make sense. > This again is a sensitive topic since we do not have methods for going from a 3D crs which is not compound to a 2D + 1D crs hence we cannot always split the envelope. > The main reason to have a 3d envelope class is to be able > and return the 3d envelope of 3d data sets as well. > As an alternative I guess I could sublcass ReferencedEnvelope, > but that would create even more confusion... It would probably make sense. Would it add a lot of load on you shoulders? Simone. > > Thoughts? > Cheers > Andrea > > -- > Andrea Aime > OpenGeo - http://opengeo.org > Expert service straight from the developers. > > ------------------------------------------------------------------------------ > Crystal Reports - New Free Runtime and 30 Day Trial > Check out the new simplified licensing option that enables unlimited > royalty-free distribution of the report engine for externally facing > server and web deployment. > http://p.sf.net/sfu/businessobjects > _______________________________________________ > Geotools-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/geotools-devel > ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
