[OSM-talk] mkcntr2.pl: perl hackers wanted to fix contours....

[simon at mungewell.org]

Hi all,
I've had a busy and very successful week in getting a downloadable GPS map
of the Crowsnest Pass compiled, hopefully I'll be able to pass this around
the local at tomorrow's mapping party to 'wet their whistle'.

See:
http://wiki.openstreetmap.org/index.php/Canada:Alberta:Crowsnest_Pass#Crowsnest_GPS_Map

One limitation that immediately jumps out is that the contours are not
graduated, by that I mean there are not gradually display in more detail
as the map is zoomed.

This does happen in the .NET version of srtm2Osm, however I'm used the
perl/gnuplot varient. An updated perl version is here:
http://trac.openstreetmap.org/ticket/621

The idea of graduated contours is explained here:
http://wiki.openstreetmap.org/index.php/Srtm2osm#Categorizing_Contours_For_Mkgmap

Basically they are additionally tags so that mkgmap.jar can mark the more
detailed contours only to appear at greater levels of zoom.


I'd love to make the changes myself, but perl is about as foreign a
language as could be. My suggestion is that a couple of extra parameters
are add to mark 'elevation_medium' and 'elevation_major' contours.

For example:
mkcntr2.pl extract.txt 10 50 100 > contours.osm
would produce minor contours at 10m separations, medium at multiples of
50m and major at multiples of 100m.

So if anyone could help, I'd be mighty grateful.
Cheers,
Simon
aka. Mungewell