Mapnik should be able to draw icon for point turned to be in same direction as direction of way on which that point lies.
This is needed to render highway crossings, power towers and other.
See crossings on Osmarender: http://www.openstreetmap.org/?mlat=50.0895787775517&layers=O&mlon=14.4224497675896&zoom=17
[springmeyer] are you sure those crossing are not actual data? (e.g. perpendicular lines draw in place)
[Petr Dlouhy] Yes, I am: http://www.openstreetmap.org/browse/node/1225805085
This is now with Mapnik 2.1.0 possible since the SVG transform can be parametrized. The syntax is following:
<PointSymbolizer file="&symbols;/SVG/crossing.svg" allow-overlap="true" ignore-placement="true" transform="rotate([angle])" placement="interior"/>
<Layer name="crossings" status="on" srs="&osm2pgsql_projection;">
select distinct on (p.way) p.way as way,
l.highway as int_tc_type,
degrees( ST_azimuth(coalesce(ST_Line_Interpolate_Point(l.way, ST_line_locate_point(l.way,p.way) * 0.99), p.way),
coalesce(ST_Line_Interpolate_Point(l.way, (1 - (1 - ST_line_locate_point(l.way,p.way)) * 0.99)), p.way))) as angle
from &prefix;_point p
join &prefix;_line l
) as v (highway,prio)
order by p.way,v.prio
) as crossing
(The PSQL query is not very elegant, but it is the best I was able to make.)
The result can be seen on http://cozpserver3.jinonice.cuni.cz/mtbmap/index.html?zoom=18&lat=50.07873&lon=14.40642&layers=000B00
To bring this feature for other users, it should be documented, even some syntax shortcuts would be nice.
This should be solved by #2621.