On 23.05.2010 20:22, Felix Hartmann wrote:
On 23.05.2010 18:24, Felix Hartmann wrote:
There is a serious bug that breaks routable maps when --route is NOT
given. This bug will in future break routing on most GPS devices and
is already inflicting Mapsource 6.16.1 and Basecamp 3.
This means that also if you compile maps that are not routable, you
have to pass the --route parameter. Else the GPS / Mapsource looks
into an empty NOD table and may crash. This will happen as soon as
you mix routable maps with the non routable mkgmap created maps.
The problem is that Mapsource and the GPS search for 63440000.NOD
data (63440000 as an example placeholder for the mapname). "Falagar",
a developer at Garmin said to release a fix for this bug in Mapsource
6.16.2 however mentioned that this fix will not be carried on to GPS
devices and will still mean a deterioration of overall routing.
I'm not sure what the exact problem for this is (I just tried even
very old mkgmap versions like 858 and also there the problem arises)
but currently this means that --route should be the compulsory for
all map creation, also not routable ones. If you have old maps (eg
transparent contourline maps) that are troublesome to rebuilt, then
opening with gpsmapedit, saving as mp and recompiling passing --route
parameter is enough to solve the problem.
I think that until the bug is found, mkgmap should adopt --route as
standard, because it may happen that if users put an mkgmap created
without --route onto their GPS besides other routable maps, these
maps might impact autorouting for the other routable maps (except if
"deactivated" on the GPS).
Just as an update. I got the following answer from Falagar, concerning
creating all maps with --route parameter:
/Naja, das ist halt nur ein Trick. Am besten waere es, die NOD-Flag zu
entfernen, aber ich weiss nicht, ob ihr wisst, wo die ist. Ich weiss
es leider auch nicht.
Es koennte evtl. ein wenig langsamer sein, wenn MS & Geraet die
Routinginformationen erst oeffnen muessen, bevor wir feststellen, dass
da keine Info drin ist.
Aber ich denke, das sollte erst einmal funktionieren. /
Translation. This is only a trick. Best would be to completly remove
the NOD-Flag, but I don't know whether you know where it is. Actually,
I don't know it either.
Eventually it could be a little bit slower if Mapsource & GPS first
has to open the routing information, until it notices that there is no
info inside.
But I think this would do if for a beginning.
So either someone finds the NOD flag (gmaptool also knows nothing
about it, removing NOD data with gmaptool does not clear the NOD flag,
) and it will be deactivated when --route is not given, or we pass
--route as mandatory, as we obviously miss something in the
implementation. I will give some really old versions a go to see if
they did it correctly and the bug got introduced with the advent of
routing in mkgmap, and send a message if they worked correctly. If not
then we probably set this flag since the beginning (but until recently
this was no problem).
Okay, there is probably no need to search for the revision that
introduced this bug. I went as far back as rev 500, and there the NOD
flag is already set, which was before we got started with autorouting.
Hence I assume we don't know about its existence, and it has been wrong
from the start.
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