It's possible to use mapxy in conjunction with TOLERANCEUNITS PIXELS but you have to understand how pixel size is computed for it to work as expected. The assumption is that there's a map associated with the point query and it's defined by a map extent, a width and a height. So, you'd need to define those somehow too. If not explicitly set as part of a query the defaults in the mapfile are used which is where things could get convoluted. I can't recall what happens if you define mapxy AND mapext with mode=nquery though, which takes precedence in setting the query method? (looks ambiguous in the code)
Practically speaking, if a query or whatever is associated with a map image regardless of client environment I *always* use imgxy, imgext and imgsize and populate those from the client and let MapServer do the conversion. Works fine with the environments I use frequently (e.g. OL and dBox). This site does it extensively via OL: http://www.dnr.state.mn.us/waters/csg/index_beta.html Steve >>> Brent Fraser <[email protected]> 10/01/09 10:51 AM >>> I'd like someone to confirm my understanding of using nquery/mapxy/TOLERANCE/TOLERANCEUNITS. GeoMoose v1.6 sets mapxy and imgext (along with mode=nquery and imgsize) CGI variables when doing an "Identify Feature" operation. I'd like to use TOLERANCEUNITS PIXELS (and TOLERANCE 3) for my point layer because I think it's more intuitive over a range of scales (as opposed to TOLERANCEUNITS METERS, TOLERANCE 500). This is not possible as using Mapserver's mapxy requires the map file to have TOLERANCEUNITS METERS to work properly. If I want to use TOLERANCEUNITS PIXELS, I must use imgxy instead of mapxy because mapserver does not do the conversion from mapxy mapping coords to imgxy image coords. Is this correct? Thanks! Brent Fraser _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
