Trying to write complicated rendering rules I am for this to simplify, and reduce the number of rules. It will make maintenance much simpler too
Aun Johnsen user Skippern sent from Android On Apr 28, 2012 3:51 AM, "Komяpa" <[email protected]> wrote: > Hi! > > > This would allow an object to be checked for the existence of a highway > tag (for example) exactly once > > I'm not sure that it's the thing worth implementing. > All this stuff can be guessed by engine on stylesheet parse time, > considering you support "exit" statement. I still think it's a hack, > and for me (in both komap / kothic js) stylesheet gets compiled into > native python/js code, so it's fast anyway. > > If you want to omit a lot of consecutive checks, you can make a > bitfield cache for the most popular rules. So, on parse time: > > - determine the most popular (8/16/32/64 - unsure of architecture) > rules, number these as 2^i; > - for each {style} block in sheet, remove rules that went to cache > and add a single integer that will store a sum of cached rendering > rules numbers (say "style_rules"); > - on rendering time, as a first pass do all cached checks and store > in a single integer as a sum of passed checks (say "obj_rules"); > - later, on doing checks against each {} block, do a check for > ((obj_rules AND style_rules) EQ style_rules). > > kinda that. If you do decomposition right ([amenity=telephone] is two > rules, [amenity][amenity=telephime]), you'll gain some speeds without > bringing ugly non-css into mapcss, and even on stylesheets written not > in your way. > > -- > Darafei "Komяpa" Praliaskouski > OSM BY Team - http://openstreetmap.by/ > xmpp:[email protected] mailto:[email protected] > > _______________________________________________ > Mapcss mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/mapcss >
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