Hi WanMil,
Are you still working on the mp_cut branch or do you wait for something from me? I assume that the precomp-sea handling will change when the mp cut algo changes?
Yes. I have found some problems around tagging in mps that need to be fixed for the mp_cut branch but I am working on it. I am not waiting for you. Feel free to create you own CutAlgorithm (the interface probably will change a bit but that will be no big problem).
OK, I am sure this is a complex change. Up to now I have no real new algorithm because I am not sure if the new algo should just try to avoid thin areas or if it should try to avoid small areas at all.
Another point: I think you wrote that garmin format doesn't support holes in areas, but I can't imagine what problem one gets when we just overlay one polygon with one or more other polygons.
One little thing is obvious: When selecting a point on the land area Garmin shows you all stuff at this point and that's: Land Sea Another thing is that the order of how data is drawn cannot be defined (as far as I know...). So if you have overlapping polygons it's a kind of luck which polygon is on top of the other.
I think this is by far the better solution compared to the complex algo in cutOutInnerPolygons(). I wanted to try it with --generate-sea=polygons, but I am not experienced regarding styles and TYP files. My problem: I did not find out what changes are needed in the style and what TYP file one needs to try it. It would be great if the wiki could show all needed steps.
I think the only thing you have to do is to add a rule for natural=sea and natural=land in your polygons file. WanMil
Ciao, Gerd