[mkgmap-dev] Memory problems since 1245

Tue Oct 6 12:03:50 BST 2009

On Tue, Oct 6, 2009 at 12:11 PM, maning sambale
<emmanuel.sambale at gmail.com> wrote:
> I am interested in this approach as well.  Can you please post the
> howto for this?
> In our areas the sea gets broken sometimes due to newbie editing it
> would be good if I have a permanent sea osm file to create a onetime
> sea polygon.

OK. I don't have my files here and I'm about to go on vacation, so
I'll try to list the steps here from memory:

1. Copy the style files to a new directory. Use this for the new
coastline styles.

2. In the new directory, remove everything from the points file,
remove everything except coastline from the lines file, and remove
everything except sea (or ocean) from the polygons file. (You might
have to add a sea polygon; I can't remember.)

3. Compile the map with appropriate options to use the coastline style
files, and to generate sea polygons.

- Make sure you give the new map a unique family ID, and unique file names.

- Set draw-priority to a low number (I used 10, I believe).

- You can leave away a lot of the other options (such as routing) as
they are not relevant for this map.

- If your map is small enough, you can run mkgmap on the entire osm
file instead of splitting it. (I would imagine that the Phillipines
would be small enough.)

- Set an appropriate map description, so you can easily recognise the
coastline map when you install it on your GPSr.

4. Wait a while for the map to generate. The generate-sea option
appears to always take a fair amount of time.

5. Install the map you just generated into MapSource/Roadtrip, or save
it for separate combination into a gmapsup file.

6. Compile your regular map. Make sure to set the transparent option,
and to ensure that the draw priority is higher than the coastline map
(I think 25 is the default draw priority.)

- Of course, do not use the generate-sea option here.
- Also remember to use unique family IDs, map file names, etc.

7. Install this map into MapSource/Roadtrip, if you use them.

8. Combine the two maps into one gmapsup file on the GPSr, using
MapSource/Map Install, or use another tool of your choice to create a
combined gmapsup file.

Once you install the maps on your device, you can also select and
deselect the entire maps for display.

- On an eTrex you can do this by paging to the map setup page.
- On a Nuvi you can do this by navigating to the map options area.

As others have mentioned, you can use a similar technique to create
map overlays with contours or other information. Just compile with an
appropriate new style file, a higher draw-priority, and the
transparent option. For example, I have created an overlay for public
transit in Toronto, Canada which I can turn on and off at will if I
want to find the nearest subway, tram or bus line.

I hope this helps.