Hi WanMil, attached is a patch that uses an optimized implementation of the Sutherland-Hodgman algorithm http://en.wikipedia.org/wiki/Sutherland-Hodgeman wikipedia which is much faster than the area.intersect. It is only used to create the precompiled boundaries. The improvements depend on the continent, for africa I see 130 secs with r2272 and 84 secs with the patched version. For asia, I see only a small improvement of ~ 10% On my machine, the precompilation of the boundaries is now quite often waiting for the disk. http://gis.19327.n5.nabble.com/file/n5670294/BoundarySplitter.patch BoundarySplitter.patch Gerd -- View this message in context: http://gis.19327.n5.nabble.com/Patch-Improve-boundary-splitting-tp5670294p56... Sent from the Mkgmap Development mailing list archive at Nabble.com.