v2 - also removes points with the same coordinates as the previous point. I know that this also gets done by the DP filter but it's very easy to do while rounding the coordinates and it does shrink the number of points to be processed by subsequent filters. This version of the patch should produce the same map as v1 of the patch. Unless anyone has any problems with this patch, I intend to commit it in a few days as I think the line gap-filling is worthwhile. ------- Having filled some gaps with that last little patch, I was wondering why I still had quite a few gaps when zoomed out. Obviously, the coords weren't being rounded to nearest given the zoom level. So, the attached patch does that rounding and, lo and behold, even more gaps have disappeared. Please give it a go, especially for maps that cross the equator/day line where the coords flip signs. Sure to be buggy but it's looking quite promising. BTW - this patch does not contain the last patch but they probably should be used together. Mark