Hi Gerd, is the function still invoked with —is-in-hook=landuse…, as before? Or is it now just to be defined in the Style? And which are the three parameters you mentioned?
Jan > Am 30.12.2019 um 11:47 schrieb Gerd Petermann > <[email protected]>: > > Hi all, > > with the help of Ticker I see a way to implement an is_in style function > I've created branch is-in to experiment with this. Sorry for the different > spelling is-in in the branch name! > > Unfortunately I got no response regarding the contents of the file > is-in-hook-samples-v2.osm posted here: > http://gis.19327.n8.nabble.com/Test-cases-for-possible-is-in-hook-tp5954103.html > So, Ticker and I have to guess what the function should do when a way or > polygon crosses or touches the boundary of > a polygon with the given attribute. > > The code in r4400 implements a function is_in with three parameters which > returns either true or false. > It allows a rule like this in the lines file: > highway=* & bicycle!=* & (is_in(landuse,cemetery,all) = true | > is_in(amenity,grave_yard,all) = true) {add bicycle=dismount} > > or this one in the polygons file: > # render building only when completely outside of a residential area > building=* & building!=no & is_in(landuse,residential,any)=false [0x13 > resolution 24] > > A BIG question mark is the handling of rules which change the tags of > polygons. > Assume you have a rule like this in polygons: > landuse=residential | landuse=commercial {set mylanduse=xyz} > and somewhere else > building=* & building!=no & is_in(mylanduse,xyz,any)=false [0x13 resolution > 24] > > It might not be obvious but this could produce more or less unpredictable > results as it depends on the > order in which elements are processed. > > So, Ticker suggested to say "results of the is_in function are undefined when > tags of polygons are changed". > I hope we can change this to something like "changing tags of polygons in the > style rules has no effect on the results of the is_in function" > by creating copies of elements before the style rules are applied. > > Gerd > _______________________________________________ > mkgmap-dev mailing list > [email protected] > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev _______________________________________________ mkgmap-dev mailing list [email protected] http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
