Hi WanMil, WanMil wrote
Using the closest approach you would cut between point 6 and 1. But this intersects the outer polygon so it's not a good idea... So you have to add some costly checks which point is directly connectable. There is an algorithm (I don't remember the name) that calculates which points are directly visible from a given point. If you want to implement it would work. Just search Wikipedia and the polygon algorithms. You will find it. I guss it's not very nice to the performance...
So if you can realize it it probably will be a good approach. The algorithms are a bit more complex than it seems on a first sight.
yes, it turned out that the Line2D.ptSegDistSq() method used with the mapunit values is fast enough, but much too imprecise. I found uk.me.parabola.util.QuadTree.distanceToSegment() which gives much better results, but is very CPU consuming. I still don't fully understand why the spherical calculation is needed since I only search for the smallest distance, not the real value :-( Attached is the result of a split of a semi complex relation: http://www.openstreetmap.org/browse/relation/108513 mpcut-connect.zip <http://gis.19327.n5.nabble.com/file/n5746915/mpcut-connect.zip> I am now looking for a simple way to reduce the costly calculations of point to line seqment distances. Maybe some Voronoi diagram can help, but I fear that this all ends up in a lot of code with many special cases :-( Gerd -- View this message in context: http://gis.19327.n5.nabble.com/shapes-with-holes-tp5745424p5746915.html Sent from the Mkgmap Development mailing list archive at Nabble.com.