[mkgmap-dev] Contour lines without elevation. What shoul mkgmap do?

Wed Oct 11 12:26:53 BST 2023

Ticker Berkin <rwb-mkgmap at jagit.co.uk> writes:

> Looking at the code, there shouldn't be any crash from mkgmap if a contour line doesn't have an
> "ele" tag. I assume the Garmin device will just draw the appropriate line without a label. This
> might be common where alternate contours are not given heights.
>
> So, no; I don't think you should add any checks.

I'm just barely reading list mail, but I agree with Ticker.  A contour
line without an elevation still makes sense, at least enough sense that
it shouldn't be rejected.

However, I don't really grasp Gerd's comment about elevations used for
routing.   Presumably that is in some newfangled Garmin device that
proceses a route with respect to contours?  If so, then I see how this
is really hard, choosing between:

  reject

  accept

  accept only if some flag is or isn't given, to be set depending on if
  one is building maps for routing/elevation devices