[mkgmap-dev] Options overhaul

Tue Mar 29 15:50:56 BST 2011

The aim is not just to remove options, but is much more about
improving how it works in the default case without options, or to
remove the need for various options altogether that only ever existed
to work around some bug that is fixed or could be fixed very easily.

The problem with --remove-short-arcs is that it is not optional.
If it is not given then routing will break and you get streams of
'error' messages that are of no help to anyone, since the map data is
perfectly fine. To create a correct routing network mkgmap has to deal
with short arcs in the network.

The --ignore-osm-bounds option was only ever a work around for mkgmap
not dealing with files containing several bounds as produced by josm.
This option is not harmless; if used with several tiles produced by
splitter it will destroy inter-tile routing.  And yet there are several
places on the web that demonstrate exactly that problem [1]

Another example: --no-sorted-roads, this is documented as making
mkgmap run faster, but as far as I know it never did (there was some
completely different reason for why mkgmap was running slow at the
time this option was introduced). The downside of the option is that
it produces a broken map where any kind of searching for roads is
likely to fail. Again it is not optional; the roads have to be
sorted, and even if it did take longer, that is just the price that
would have to be paid to create a working map.

A quick search shows that people are actually using this option
and so producing broken maps.

..Steve

[1] Eg, just to pick the first one I found (there are many more)
http://acrosscanadatrails.posterous.com/making-routable-mapsource-maps