logo separator

Improved splitter released


Congratulations on a much improved version of splitter that was released today by Gerd Petermann.

The first improvement is that it fixes the annoying failures on large multipolygons such as lakes and forests and also on long ways such as ferry routes or country borders.

The previous method used by splitter could not guarantee that all features that should affect a tile but were wholly or partially outside of the tile would be correctly included. The new version tracks down all these cases and makes sure that they are complete.

Currently you have to supply the --keep-complete=true option to get the new behaviour, but as the results are so much better this will surely become the default soon. It does take a little extra time and more memory with this option, but as the resulting file sizes are smaller, it takes less time to run mkgmap on them so there is not so much difference in the overall time taken.

The split is also improved to make the tiles sizes more even. This means both a more consistent number of points within the same tile and the tiles are more square with an maximum aspect ratio of 1:4 if possible with the given input file. More care is taken with tiles that approach the poles or the 180 degree of longitude line.

The o5m format is now supported for both read and write. The o5m format is somewhat quicker when used as a splitter input file.

There are also loads of bug fixes too! This is all available in release r263 which can be obtained as always from the splitter download page There are many more changes than are mentioned here, so for full details read the full description [1]

General information on how to use splitter can be found at the tile splitter page.

Posted by steve on 17 Dec 2012

Latest commits

  • mkgmap-r4767 raise minimum resolution of overview map to 13 to match the alignment of tiles produced by splitter with default resolution ....
    11 jun 2021
  • mkgmap-r4766 map-split.patch - fix possible "Problem writing line ..." message which caused data loss of huge polygons.
    11 jun 2021
  • mkgmap-r4765 rework roundabout checks (roundaboutchecks4.patch by Mike Baggaley).
    10 jun 2021
  • mkgmap-r4763 - fix bug in Coord.distToLineSegment(Coord a, Coord b), it returned Double.NaN when a and b are the same.
    08 jun 2021
  • mkgmap-r4760 minor performance tweak: only create node instance when it is needed.
    06 jun 2021
See more...