[mkgmap-dev] Commit: r1410: Add --merge-lines option to combine lines at lower zoom levels.

Mon Nov 30 12:42:27 GMT 2009

Felix, Johann,

> > Okay, the merge-lines seems to be responsible for it! - However also 
> > very aggressive dp filter settings might cause the tooltip to show up 
> > slighltly away from the mouse (the tooltip will show up where the road 
> > would be in resolution 24) - however only when using --merge-lines the 
> > tooltip distance gets so great that sometimes it actually breaks using 
> > the routing tool in Mapsource. Aggressive dp filter alone (=10) cause no 
> > damage.
> >
> Only to be sure I understand you correctly:
> If you dont use the merge-lines option, then the error with the tooltip 
> does not appear? If this is the case, then the fault lies for sure in 
> the newly introduced merge line code.

I can confirm that this issue exists. I think it's related to my
posting the other day where I talked about the disparity between
graphical lines and the routing arcs when the lines are being merged.

My guess is...

After merging you have 1 graphical line that spans the length of the
combined lines associated with a routing arc that only spans the length
of the original un-merged line. When you put the cursor near the lines
that have been merged, mapsource, finds the arc associated with that
line and puts the pop-up as close to the cursor as it can while still
being on the arc. As the arc only spans a part of the whole merged
line, the popup jumps (away from the cursor) to the end of the arc away.

It's not really that surprising given the resulting data
structure that has been produced by the merging.

Cheers,

Mark