[OSM-dev] mod_tile svn's project variables 1)hardcoded 2)in many files

Frederik Ramm frederik at remote.org
Wed Feb 3 01:52:51 GMT 2010


Jonathan-David SCHRODER wrote:
> As to precision issue, someone earlier on this list told (using the ruby 
> code as a prof) that the rails port would allow to store vector data 
> with integer precision up to 7cm without modifying anything to the rails 
> port (and for JOSM I don't know).

I think that's true. With one pixel being 4cm on z22, this means that 
already on z22 you have the issue that there will be some pixel 
positions where OSM doesn't let you place a node because of lack of 
precision and rounding errors. Not a big deal but at some point zooming 
in further will just give weird results ;-)

> As Dane Springmeyer had warned/advised me earlier on IRC, for my indoor 
> rendering thing, I don't want to use mod_tile (even though I could use a 
> tree as you say instead of this 2-dimensions array... while I could just 
> use bash's sort --unique option on osm2pgsql's expiry list file before 
> calling render_expired)...

No, you would have to use a little more logic than that because you want 
to replace each x and y value by int(n/8)*8 so that you only have one 
line per meta tile.


Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"

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