[mkgmap-dev] Tiles pruned in DEM map

Wed Jan 6 15:14:15 GMT 2021

Hi Gerd

Thinking about this more, any attempt at merging will most likely cause
violation of the rule that all overlaying polygons must be in the same
subdivision.

Also, just feeding all the points/lines/polygons back through the non
-order-by splitting process could cause similar problems, so my current
solution might give incorrect results. I think this is very unlikely
and my preference would be to wait for someone to have this problem -
it hasn't been reported in the 4 or so years that it could have
happened.

A solution is to preserve the subdivision structure and content from
each ovm_, linking, per level, the ones from each source. If there is a
single one per tile/level and it fits, the 0x4a polygon can be added
in, otherwise an extra subdivision is added to hold it.

Ticker