[OSM-dev] osm pre-processing API. Was: Re: Intelligent fitting street names in OSMarender

Frederik Ramm frederik at remote.org
Sat Mar 10 13:42:14 GMT 2007


> Anyway, the advantage of having this as a preprocessing step as has  
> been pointed out by Frederick, Jochen is that it removes any  
> dependancy on the format of the osmarender svg. As a pre-process  
> step, it also removes the dependancy of osmarender as a renderer as  
> well, so other renderers might make use of it.

Yay ,-)

The text fitting stuff could also be elegantly solved in pre- 
processing. As far as I understand, Osmarender cannot reasonably  
compute the length of a way; it can say "put this text on that way"  
but it can never know whether the text will fit. If it knew the  
length of the way it could at least drop the text from ways that are  
much too short, or maybe even apply heuristics to select a shortened  
version of the name.

So if the pre-processor would add some kind of length attribute to  
the way, that would perhaps enable Osmarender to make a good decision.

As pointed out some time ago, the map projection could also be fully  
moved out of Osmarender into a preprocessing step, making projection  
more flexible and exact. This, however, would be something that makes  
the preprocessing step mandatory instead of optional... maybe  
Osmarender can be tweaked to "use supplied northing/easting values of  
nodes if present, otherwise apply own projection".


Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00.09' E008°23.33'

More information about the dev mailing list