[mkgmap-dev] resolution, level & levels

Thu Sep 13 16:16:01 BST 2012

Oh, thank you. So would it be worth amending the documentation for

o level, to add...

Note that if a level number is used which does not appear in the /levels/ 
specification, then it is treated as the next larger (or should this be 
smaller?) level number which is present.

o resolution, to add...

Note that if a resolution number is used which does not appear in the 
/levels/ specification, then it is treated as the next larger level 
number which is present.

o levels, to add...

Note that, if levels is not specified explicitly, then the defaults are 
as if

   levels = <whatever>

had been specified.

-- 
Cheers,
John

In article <5051EE89.2060003 at gmail.com>, extremecarver at gmail.com says...
> 
> Everything goes down to resolutions, but in the resolution / levels file 
> in the style, you still need to define, which resolutions are actually 
> input to the map. If resolution 23 is not actually a resolution that 
> exists (as by default) - then 23 means it will only be put into 24.
> On 13.09.2012 12:53, John Aldridge wrote:
> > I'm confused about the way resolution, level and levels interact.
> >
> > I started with a set of supplied styles (actually from Marco Certelli's
> > CreateIMG package) which used resolutions 14, 16, 18, 20, 22 & 24 for
> > various kinds of roads. I wanted to change residential roads to come
> > higher than tertiary roads (resolution=22) but lower than footways &
> > tracks (resolution=24), so I changed them to be at resolution=23.
> > Unfortunately this didn't work -- they appeared and disappeared at the
> > same time as the the resolution=22 tertiary roads.
> >
> > I then changed the levels specification from the supplied
> >
> >    levels = 0:24, 1:22, 2:20, 3:18, 4:16
> >
> > to
> >
> >    levels = 0:24, 1:23, 2:22, 3:20, 4:18, 5:16
> >
> >
> > and everything sprang into life working as desired. This behaviour was
> > consistent between BaseCamp and my Oregon.
> >
> > The documentation in
> >
> >    http://wiki.openstreetmap.org/wiki/Mkgmap/help/style_rules
> >
> > had led me to think (though I guess it doesn't say so explicitly) that
> > level & levels were meaningful only to the Mkgmap compiler, and were
> > converted to resolution in the final Garmin format map files. As a result
> > I was surprised that changing the levels specification had any effect at
> > all, since all rules used resolution rather than level anyway.
> >
> > Could anyone shed any light on this behaviour? Thanks!