[Openstreetmap] new static renderer, and other bits

[Lars Aronsson]

SteveC wrote:

> > new scale = old scale / 5.0e8

> How did you prove this? You're sure its linear? If so I'll put
> 'openmapscal=foo' if its needed.

I didn't prove it, I just tried some values and this worked for 
me.  Map coordinates in susning.nu (for those who can edit this 
now closed wiki) use the syntax map:58.4:15.6:100000 for links to 
a map centered at 58.4 N, 15.6 E, size 10 cm and scale 1:100000 
(assuming some normal screen resolution).  The scale indicates the 
size of the geographic object (diameter in decimeters): small or 
large city, province or country. As it happens, this syntax was 
also used in URLs for the old mapblast.com before that mapping 
site was acquired by Microsoft and closed down.  So in several 
hundred of susning.nu's pages, there are map coordinates like 
this, and on display they are transformed to a number of links to 
mapping sites that are still open.  You can see this on a page 
like http://susning.nu/Link%f6ping near the green GeoURL logo.
The links used to include 
http://www.openstreetmap.org/edit/viewMap.jsp?lat=58.4&lon=15.6&scale=100000 
but after July 13th, I had to add this line of code to my Perl 
script:

    $scale = sprintf("%f", $scale / 5.0e8);

and that seems to take care of everything.

> > Don't the north-south arrows make too long (non-overlaping) jumps?
> > Is this related to the change in image size?
> 
> I'm not sure what you mean?

When I go to
http://www.openstreetmap.org/edit/viewMap.jsp?lat=58.4&lon=15.6&scale=0.000200
and click the up arrow to pan north, it goes directly to
http://www.openstreetmap.org/edit/viewMap.jsp?lat=58.46&lon=15.6&scale=2.0E-4

I think the jump from 58.4 to 58.46 (the north-south increment) is 
too long.  There is no overlap, but instead a part is missing.  
Jumping to 58.45 makes a zero-overlap jump.  Best would be 58.44.

The east-west increment is just fine.  And the north-south 
increment in the editing applet is also just fine.


-- 
  Lars Aronsson (lars at aronsson.se)
  Aronsson Datateknik - http://aronsson.se