[mkgmap-dev] White stripes in the sea

Thu Jan 3 19:51:10 GMT 2013

> So in ASCII art it's the following situation:
> (s = sea polygon, each l = single small land polygon)
> 
> ssssssssssssssssss
> slllllllllllllllls
> slllllllllllllllls
> slllllllllllllllls
> ssssssssssssssssss
> 
> In the end it is also a problem of the resolution dependant mp cut 
> algorithm. At first it would remove all small single land polygons. But 
> in an improved algorithm it could try to merge the land polygons.
> 
> I guess merging will be quite complex:
> - What should be done if two small mergable polygons have some tags in 
> common but also some different tags? How is the merged polygon tagged?
> - How should the algorithm detect that two polygons can be merged when 
> they are not connected to each other? It could calculate fractions for 
> each resolution dependant "pixel". So on one pixel the sea might be 30% 
> and land 70% and therefore land wins and the pixel is assigned as land. 
> This requires a good merging algorithm for pixels...
> - ???

Well, let's postpone this for now, if it can be done we can do it later.
I've just realized that cutOutInnerPolygons() is called before 
the StyledConverter. Will the style system be able to 
handle data that is repeated for each resolution?

I wonder if the coastline data is really a good reason to change 
the program logic that much. I think it is a special case and maybe
it would be better not to pass the data through the same routines?

Gerd 

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