I was wondering how the sea is generated in those recent sea polygon patches. Since I don't understand Java I haven't a clue! Even so, I was thinking of what might be a reasonable way to do it.
If there is coastline present within the bounding box then rapidly "grow" the coastline from the bounding box until you are close to coastline. Then grow the coastline more slowly (smaller overlapping polygons). At this point maybe a test could be done to see if a closed coastline way will end up completely inside a proposed polygon and if it will it's time to make the polygons (temporarily) smaller. In this way the sea should end up "shrink wrapping" itself around land. Maybe it's already done in a way like this but as I say I wouldn't know. I also thought it might be an idea to build a "convex hull" of the coastline whereby a a rough outline of the coast is built first so that all land lies on one side of this outline. This could be done by sampling the coast and checking no lines joining pairs of coastline points intersect with another coastline point (which would mean the possibility of coastline on both sides of the line segment). That could be a way to rapidly fill in most of the sea area. All the best, Cliff _______________________________________________ mkgmap-dev mailing list [email protected] http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
