A few comments inline. On Tue, Mar 31, 2009 at 3:26 AM, Christian Müller <christian.muel...@nvoe.at> wrote: > > Last week I posed a question about having a FeatureSource which has also > some generalizations of the vector data to speed up response time and reduce > data transfer. > > While it is is surely not the problem to implement such a FeatureSource, I > need the ScaleDenominator from the caller. > > I studied the source and I want to ask the specialists about the following > assumptions: > > 1) StreamingRenderer and ShapeFileRenderer use > FeatureSource>>getFeatures(queryObject) > 2) The Query interface offers the possibility to pass Hints > > My idea would be to pass the scaleDenominater as a hint to the queryObject. > This makes sense since the scaleDenominator is only usefull for some use > cases and should not be part of the FeatureSource API.
Indeed; this is a good approach and you may find such information already available; used to control decimation. > I am not sure here if the ScaleDenomintar is enough, perhaps a unit of > measure is also required. On the other side, the Query interface offers a > getter for the CRS, I think I can get the unit from the CRS, yes or no ? It depends how you want to think about the problem; you may also be considering the data CRS? You may wish to explore where to perform your generalization? Before decimation or after? Before transformation or after? > Anyway, if my assumptions come close to the truth, I would do such an > implementation and insert one line in the mentioned renderer classes to test > it. > > opinions ? Sounds good; you should be able to provide a hint to the renderer prior to calling; ie you may not even need to insert a line in the renderer classes for your experiment. Jody ------------------------------------------------------------------------------ _______________________________________________ Geotools-devel mailing list Geotools-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-devel
