[mkgmap-dev] Holes in the Sea

Fri Feb 17 21:29:23 GMT 2012

On Fri, Feb 17, 2012 at 05:14:53PM +0100, RheinSkipper wrote:
>Also attached is a screenshot of those terrible holes in the sea.

I do not have idea about the max-nodes in the splitter, but the holes 
are so regular that they should be relatively easy to figure out.

Can you determine the tiles corresponding to the holes? Are there any 
natural=coastline ways in the tiles? If not, mkgmap should assume that 
the whole tile is land. I would start by checking the hole south of 
Nizza, as it is smaller. Try to convert the tile.osm.pbf to XML format 
with Osmosis and then do grep 'natural.*coastline' tile.osm. If there is 
no match, then my guess should be right.

I have had the opposite problem. Someone added an island to a lake with 
natural=coastline. Previously, the tile had no natural=coastline ways 
(it was all land). The result was that everything except the small 
island was converted to water. mkgmap did not produce a warning; 
technically, it could warn about overlap between natural=water,
waterway=riverbank and natural=coastline.

>If it´s a memory issue, which options can I modify to save memory?

As far as I understand, the 'area too small to split' and related 
messages are due to limitations of the Garmin map format and of Garmin 
devices. They do not have that much RAM to play with; that is why the 
map tiles must be relatively small.

I hope that this helps.

	Marko