andrea antonello ha scritto: > Hi, I am trying to get offset for points inside the style editor for udig. > The only way to do offset I found around is here: > > http://docs.geoserver.org/stable/en/user/styling/sld-extensions/geometry-transformations.html#drop-shadow > > The problem is that the offset like that is in map units, which is not > exactly what I hoped for, since the preview window is in pixels and > also in the case I would want to create a composed mark, I would need > to define offsets in pixels. > > Is there any other way to do offset of points?
I can't think of a quick and sane way that actually works in all cases. One way could be to set the scale denominator into the env function, and compute an offset in real world units given the scale. But that would not work nicely if the rendering is reprojecting the data from a geographic srs to a projected one (as the scale would say something only about the projected to screen transform). Another way would be to add a unit of measure onto the geometry element, or use the symbolizer unit of measure, but that would have even less sense. Not using <geometry>...</geometry> in a symbolizer, and assuming you have a shapefile, so that we konw the geometry attribute name, it 100% equivalent to stating: <geometry><PropertyName>the_geom</PropertyName></geometry> Now, if we add a unit of measure attribute on that what do we mean, that we want to consider the geometry coordinates, expressed in lon/lat, as pixels directly? A sane way would be to introduce a transformation that explicitly works against the geometry past the reprojection and on screen transformation: <renderingTransform><function name="offset"> <PropertyName>the_rendered_geometry</PropertyName> </function></renderingTransform> where "the_rendered_geometry" is a conventional name to gather the geometry as transformed from its native srs into the rendering one, and from there on screen (so, a geometry whose unit of measure is pixels, a "screen geometry"). Now, finding the time to do that and dealing with the require API changes required in the Symbolizers... hmmm... not sure when that is going to happen Cheers Andrea -- Andrea Aime OpenGeo - http://opengeo.org Expert service straight from the developers. ------------------------------------------------------------------------------ This SF.net email is sponsored by Sprint What will you do first with EVO, the first 4G phone? Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first _______________________________________________ Geotools-gt2-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
