[mkgmap-dev] Multilayer Map in MapSource?

Thu Dec 17 08:08:58 GMT 2009

On 12/16/2009 11:57 PM, Fips wrote:

> What I did till now: I generated a map with one single layer with mkgmap 
> and installed that into MapSource. Now I found out that there's also the 
> possibility to create a map with multiple layers (contours, basemap and 
> routing map).
> 
> Does anyone has an instruction which commands and ids I have to use? I 
> already tried some things but without success till now.

For getting multiple map layers on the GPS unit you need more than one
family ID. The lowest map must not be transparent, the upper ones need to
be. The template.args might look like this:

gmapsupp=yes
family-id=1234
product-id=1
family-name=Map1
draw-priority=25
transparent=no
mapname=10000001
input-file=1.osm
mapname=10000002
input-file=2.osm
family-id=5678
product-id=1
family-name=Map2
draw-priority=28
transparent=yes
mapname=20000001
input-file=3.osm
mapname=20000002
input-file=4.osm

For Mapsource things are different. Mapsource does not care about the draw
priority. It draws the maps in the order of the mapname. So the transparent
layers above have:
- a higher draw-priority for the GPS unit
- a higher mapname number for Mapsource

You can import only one family at a time into Mapsource. So the above
example will create a gmapsupp.img which is fine on the GPS unit, but you
cannot load both layers into Mapsource. For this you need a second
template.args file. This one just creates the TDB file for Mapsource using
the images create in the first step:

gmapsupp=no
tdbfile=yes
family-id=1234
product-id=1
family-name=Map1
mapname=10000001
input-file=10000001.img
mapname=10000002
input-file=10000002.img
mapname=20000001
input-file=20000001.img
mapname=20000002
input-file=20000001.img

If you use TYP files you need two seperate TYPs for the GPS unit (for the
two FIDs) and one TYP for the mapsource (because there is only one FID). The
FID is not stored in the map tiles, only in in the TDB file. So you can use
a different one if you like without recreating the map tiles.