Andrea, I am not sure what you are meaning "same data source can provide different geometries properties"
1a) I assume you mean that within one feature type we can have more than one geometry property. Since a feature has a default geometry, this is the one we should use. If I have a feature with more geometry properties with different CRSs, it is my responsibility to generalize all geometries in a proper way in advance. If you have no distance for the default geometry --> no hint 1b) If you mean you have to render layers with different CRSs, I see no problem. The generalization difference is individual for each feature source. 2) Having different CRSs within the geometries of one geometry property, forget it. No hint. I dont want to make a master thesis about CRS calculations. Btw, which names should I use package: org.geotools.data.gen FeatureSource org.geotools.data.GenFeatureSource ..... Andrea Aime writes: > Christian Müller ha scritto: >> But anyway, I do not want any generalization on the fly and 1) is my >> first target. >> >> Passing difference/offset in the native CRS as a hint would make me happy >> :-) >> If the hint is missing, you always get the base geometries, the same >> holds true if the value of the hint is 0. >> >> I would like to avoid CRS transformations to be consistent with other >> FeatureSources. >> >> Pleasy give me a hint and I would start. If possible in 2.5.x and 2.6.x, >> I need this feature in geoserver. > > Hum, I looked into the streaming renderer code and the thing is not that > easy unfortunately, as the generalization distance in the general case > has to be evaluated on a feature by feature basis: > - the same data source can provide different geometries properties > in distinct spatial reference systems. In this case, no single > rendering hint can be provided > - the same column can contain geometries with different spatial > reference system too. I know it sounds crazy, but as far as I remember > OGC WFS makes sure that you can handle that case as well... mixed > with the fact that in GeoServer you have to declare a SRS anyways > (we have no way to support a srs-less dataset at the moment) > it means the code cannot just check if the native SRS is null > (which is what I would expect from a mixed SRS geometry column). > Btw, Justin, can you confirm the above or it's just my memory failing > me? > > So it seems I can pass down a generalization distance only if > there is no reprojection going on and the native srs has not > been tampered with? > Alternatively I guess I could pass down a generalization distance > in the rendering SRS, and pass down the rendering CRS as well. > It will be the job of the datastore to figure out if the generalization > distance need to be adjusted given the native SRS of the data, or not. > Opinions? > > Cheers > Andrea > > -- > Andrea Aime > OpenGeo - http://opengeo.org > Expert service straight from the developers. ------------------------------------------------------------------------------ _______________________________________________ Geotools-devel mailing list Geotools-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-devel
