Hi all, I've found out that this problem is caused by a flaw in the "high precision" code. Under special conditions, two points with almost identical coordinates are internally represented with very different values. There is a possible overflow in the delta values, the value +32 should not occur as it cannot be represented with 6 bits, but the calculations produce this value. I think I have an ugly fix for this but the resulting map still shows (smaller) gaps and a unit test needs corrections, so there is more to do. Attached is a patch that checks for this overflow. Work in progress and maybe causes trouble in other areas, e.g. in South America where we have negative lat/lon values. @Ticker: The unit test für LineClipperTest fails. I am not sure if only the test has to be changed (how) or if the code in LineClipper can be improved. I seem to remember that you suggested to use the code in ShapeSplitter instead. ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Gerd Petermann <gpetermann_muenchen@hotmail.com> Gesendet: Dienstag, 26. September 2023 19:58 An: Development list for mkgmap Betreff: Re: [mkgmap-dev] Gaps in surfaces Hi Michael, okay, I can reproduce the problem. I assume it is caused by the code which subtracts the inner area from the multipolygon area. No idea if this can be fixed easily. Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Forstner Michael <forstner-m@a1.net> Gesendet: Dienstag, 26. September 2023 19:44 An: 'Development list for mkgmap' Betreff: Re: [mkgmap-dev] Gaps in surfaces Hello Gerd, here is the area: https://www.openstreetmap.org/#map=19/48.57117/13.96920 I understand that it is necessary to make rounding. If a point of two surfaces is equal in OSM, the point should also be equal in Garmin. Thank you! Best regards, Michael _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk https://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk https://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev