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[mkgmap-dev] [Patch v1] Don't write useless data to NET file

From Steve Ratcliffe steve at parabola.me.uk on Fri Oct 11 23:21:59 BST 2013



>@Steve: I assume that the Garmin maps contain also 
>data for lower resolutions in NET, so maybe they also
>have NOD data that points to this while we have not? 

I doubt that the data is useless, since that is how the maps are meant to be.  I do not know what it is for, but I would guess it would be only used on a GPS device and that it would have nothing directly to do with auto-routing, since it is NOD that controls that.

It could be just used as an optimisation, rather than being essential. Or it may not be used on modern devices. Anyway lots of investigation needed before declaring it un-used.

I've noticed that we only ever seem to have one road segment in one NET entry, whereas there can be more than one. (And I thought at one time there really was multiple segment combined.)

Having a single NET entry containing multiple road lines might help routing by reducing the number of entries in NOD

Of course if we are writing the wrong thing then that is kind of useless :-) and I would not be surprised if there were several bugs.

..Steve





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