[mkgmap-dev] Optimizing MapSplitter

Wed Nov 12 14:11:29 GMT 2014

Hi Gerd

As you've probably seen I've added the program to the display svn
as test.svg.subdiv.Main. There is an argument '--level N' to display
a different zoom level. Default is 0 (most detailed).

I've found that our OSM maps seem to have a lot more elements than
other maps so it is difficult to compare.
In general the way we create subdivisions means that many of them
are quite large and they contain many elements.  There are no
small divisions.

> If I got it right, the redraw time is influenced by
> a) how many sub divisions are overlapping a given bbox and
> b) how many objects are in these sub divisions  and
> c) how complex the objects are (means, how much time it takes to render
> them)

It is also possible that the way that the divisions on different
levels link together may have an effect, as it may be able to
restrict the number of divisions it has to consider.

..Steve