[mkgmap-dev] Understanding the sea

Tue Dec 29 20:08:22 GMT 2009

Hi,

One option would be to use GroundTruth to generate MP (polish) files for 
  sea polygons and then use mkgmap to generate the IMG from these. I'm 
the author of GroundTruth and I also received a request to help generate 
marine maps for http://www.boat-duesseldorf.com/

I had some success with sea filling algorithm (I use the same for 
Kosmos): 
http://igorbrejc.net/openstreetmap/groundtruth-coastline-rendering-improved

Unfortunately I'm quite busy with coding Kosmos so I cannot invest too 
much time in making GroundTruth's MP files compile in mkgmap. But I'm 
willing to help in the effort, since I've become annoyed with 
incompatibility of cgpsmapper's license and that of OSM - it effectively 
  prohibits any maps generated with GroundTruth and OSM data from being 
distributed.

Regards,
Igor

Felix Hartmann wrote:
> 
> On 28.12.2009 23:22, Clinton Gladstone wrote:
>> On Dec 28, 2009, at 21:27, Felix Hartmann wrote:
>>
>>    
>>> cgpsmapper produced maps may not be used CCBYSA 2.0 (only non
>>> commercial). It would probably nevertheless be best to create a layered
>>> sea map instead of creating it each time.
>>>      
>> Yes, that's true regarding the license. I suppose it would still be possible to generate the sea polygons from another (public domain) source and distribute the sea layer separately from the OSM layer, but that's a hassle both for the person generating the map, and users of the map.
>>
>> Cheers.
> Well I don't see anyhow why cgpsmapper should be able to correctly 
> render them. Anyhow the most convenient would be to have static osm sea 
> only files, which are in such a format that mkgmap can use them easily. 
> Then it would be just a matter of adding for each country the respective 
> sea data (static) in osm format.