[mkgmap-dev] Configuration for overview map

Thu Apr 4 20:24:00 BST 2013

Hi Gerd,

thanks for your effort in this big open point in mkgmap!

>
> The following points were discussed:
> 1) Allow to read data from other levels, not only the one with the lowest
> resolution.
> I tried it and I don't think this will increase quality, but it increases
> run time quite heavily.

Ok, it was just an idea. I think it should be proposed to use --merge-lines.

>
> 2) Allow to apply filters, so that fewer objects are placed in the overview
> map.
> I think this could be implemented with a simple list like this:
>
> # filter for overview map
> point:type_1
> point:type_2
> ...
> point:type_n
> line:*
> polygon:
>
> This would add points with the type type_1 to type_n, all lines and no
> polygons.
> The file woud replace the --x-overview-add-xxx options.
> I will try to implement it in this way, please suggest changes if something
> else is needed.

Maybe someone requires to configure reading data from specific levels. 
By default you would read from the lowest level but one could 
reconfigure it, e.g.:
point:type_1:level
point:type_2

So type_1 is read from the configured instead of the lowest level.
This could be put on the TODO list until someone asks for it :-)

>
> 3) Style files for the overview map
> I don't see how this could be used when the data is read from *.img files.

I have two ideas:
1. a separate overview style file. When reading from .img files you 
would only check the element type definitions. All Garmin types used in 
the element type definitions would be used.
2. Add an overview statement to the element type definitions of the 
common style files. This could also be checked if reading from img files.

Anyhow your solution with the config file does the same although it uses 
a new "format" of config file.

>
> 4) Read data from other sources, e.g. precompiled sea/land polygons.
> I don't plan to code that but I think this remains a possible option to
> increase quality.

Ok, can be added later on if required.

Thanks!
WanMil