[mkgmap-dev] Preparing merge with trunk for branch NET-no-NOD

Tue Nov 5 10:33:12 GMT 2019

Hi all,

besides the new island detection the major changes are:
- reduced IMG size (NOD). The trunk version converts all road ends to so called routing nodes and also adds arcs to those nodes. Think of a +-shaped crossing where only the southern end is connected to another road. The trunk versions adds three route nodes and at least 6 arcs for the unconnected ends.
I found no good reason for this. The data is probably completely ignored by Garmins routing algo, so the branch version doesn't do this.
- routing and address search work with maps that use resolution 23 for level 0 (instead of 24). To use this the style must NOT add any objects with a minimal resolution of 24. More general, it must not use a minimum resolution that is higher than that given for level 0. 
(I did not intend to code that, I just found the error that causes a problem in the trunk version, the RoundCoordsFilter removed special nodes.)
In most cases one would replace lines like
(aeroway=taxiway | aeroway=taxilane) & area!=yes {name '${ref}'} [0x27 resolution 24 continue]
by
(aeroway=taxiway | aeroway=taxilane) & area!=yes {name '${ref}'} [0x27 level 0 continue]
to use this BUT probably some objects really should not be added to such a map, e.g. buildings, so I see no good way to automate this, so mkgmap stops with an error message if the style is not adjusted like this.
- improved polish format (*.mp) reader no longer ignores empty Numbers ("x,N,-1,-1,N,-1,1") as they improve the address search result.
- reduced NET size when map is not routable  
The trunk version stores information in NET which is only needed for routable maps. 

If you have doubts about any of the changes please try to find a place where the branch doesn't work (better) than the trunk version.

Gerd