Hello Andrea I don't have any code around me right now, but I can tell you my understanding of this topic: - DPI should affect the pixels/meter ratio (map scale). - Symbolizers given in meters should not change apparent size when DPI varies, as the size of the map in meters also remains the same. In this situation, when DPI increases the sizes in pixels of both the map and the symbolizers should increase proportionately. - Symbolizers given in pixels should have a SMALLER apparent size if DPI increases: the same number of pixels now represent a smaller size in the real world (more dots in the same inch)
That said, I don't think that a new rescaling step should be necessary. My feeling is that the DPI setting should affect the map scale (pixels/meter) passed over to the UomRescaleStyleVisitor. Of course, it could be ME who is missing something :P Cheers Milton Andrea Aime wrote: > Hi, > I'm looking into exposing the DPI setting as part of > the GeoServer WMS request, mostly so that people can > get images to send to a printer with a certain DPI. > > (note: the streaming renderer already takes a hint > allowing to specify the DPI) > > What I expect to see is that the symbolizers sizes > increase as the DPI increases, and also that > the scale computation changes accordingly. > > I guess that the UOM and DPI rescalings should be independent, > so that DPI rescaling works also with symbolizers whose > size is specified in pixels. Am I right, or I'm getting > confused? > > What I see now is that using DPI and UOM in combination > (and without a custom rescaling step for DPI) > does not affect the size of the symbols on the map > because the UOM rescaling computes the rescaling factor > in a way that's DPI independent. > > Yet what I'd expect to see is that increasing the DPI > should increase the symbol sizes. > However, that should also happen when I'm not using UOM. > > So I think I should introduce a separate rescaling step in > streaming renderer to be used when the DPI is not > the default value. But I wanted to double check that. > > Am I missing something? > > Cheers > Andrea > > PS: I see we already have a generic RescaleStyleVisitor, > I guess I'll use that one for DPI handling (maybe double > checking it's doing all the same rescales as the uom one, > which has quite some unit tests backing it) > -- Milton Jonathan Grupo GIS e Meio Ambiente Tecgraf/PUC-Rio Tel: +55-21-3527-2502 ------------------------------------------------------------------------------ ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
