[mkgmap-dev] [PATCH] alpha patch (V4) for simplifying ways and reducing img size

Wed Apr 15 12:06:23 BST 2009

On Mon, Apr 13, 2009 at 1:50 PM, Johann Gail <johann.gail at gmx.de> wrote:
> Yes, I made the same observation. The highways gets drawn segment by
> segment. Therefore I introduced the switch --merge-lines, which should merge
> the segements.

Although drawing performance was definitely improved, a lot of routing
issues cropped up when I tried this in the field.

- The routing issues seem similar to those which occurred before Mark
Burton committed the MAX_POINTS_IN_WAY = 200 patch. Could it be that
merging the highways pushes the number of nodes above this limit?

- I also noticed frequent recalculations while driving. I have the
sensitivity patch applied. Is it possible that the smoothing algorithm
causes the ways to diverge enough from the actual route to trigger a
recalculation? (I set the --reduce-point-density option to the
default.)

- There was also a lot of weirdness in roundabouts. I was often routed
the wrong way, or back and forth on the roundabout. Perhaps the
merging is sometimes overzealous? Would it be a good idea to exclude
roundabouts from smoothing and merging?

Cheers.