[GraphHopper] Looking for an engine for horse (and hiking) routing

[Peter K]

Hi Nop,

>> feel free to optimize whereever you can - I appreciate every
>> improvement! The parser could be improved in many areas e.g. adapted so
>> that the protobuf protocol is supported (this would be faster IMO).
>
> That might be a little faster, but I have something else in mind. I
> spotted some unneccessary operations, but there is a fast way to skip
> over all of the nodes in the 2-pass Reader and immediately parse the
> ways. For large files this is much faster than parsing and ingoring
> them, but it only works in uncompressed osm xml.

Ah, ok. Also putting parsing and storing the edges into two threads (+ a
queue) could speed things up.

>
>>> 5. How would you start adding elevation data?
>>
>> See the previous discussion:
>> http://lists.openstreetmap.org/pipermail/graphhopper/2013-May/000118.html
>>
>> and let me know in the ticket where information is missing.
>
> @Robert: Are you working on adding elevation yet?
>
> When you are talking about directed edges do you mean adding two
> one-way edges replacing the two-way edges? This would almost double
> the graph. I noted that FORWARD and BACKWARD are in the flags, so
> there must be a check for direction already. Could this direction be
> used in the Weight calculation during routing, thus avoiding duplicate
> edges? (provided you don't use CH)?

Yes, that would be an option (for CH it won't work).

>> You won't break things. Fork graphhopper on github and create a new
>> branch at your fork (e.g. issue-43). ...
>
> Ok, I have forked and started playing.

Nice, have fun :) ! I've also created this contributing file:
https://github.com/graphhopper/graphhopper/blob/master/CONTRIBUTING.md

Let me know if you have questions!

Regards,
Peter.