Thread: [Announce] modRana: a flexible GPS navigation system
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Wikiwide is offline Wikiwide
2010-09-04 , 13:16
Posts: 2,006 | Thanked: 3,351 times | Joined on Jun 2010 @ N900: Battery low. N950: torx 4 re-used once and fine; SIM port torn apart
#172
Originally Posted by MartinK View Post
But seriously, the buttons need to be distinct even in sunlight and from a distance, as in the case of car or bicycle navigation.
As all the PNGs are already (manually) generated from a SVG file, I would like to replace them directly by SVG icons in the future.
Well, yes, it is a bit against the fremantle GUI metaphor, but:

* you can easily go back to previous menu with your thumb when holding the N900 in your left hand
* in most default modes you can also access the main menu by your left thumb and navigate the map with your free right hand
* the fremantle style "back" buttons always seemed too small to me
* it is hardcoded in quite a few places
* all menu levels have the same simple and easily comprehensble structure
* it follows the ancient tradition of latin script, by adding elements in rows, from left to right, top down
Agree completely.

Originally Posted by MartinK View Post
Unfortunately, plain OSM XML data can not be used (most probably because of the xml processing overhead)
Why? I have a 137KB *.osm file (do not use anywhere yet, just downloaded to look at it). Is routing that difficult?
One possible approach:
take current coordinates;
take coordinates of destination;
generate vector of needed direction;
find the closest node (not more than 5 minutes away from current coordinates);
find the ways including this node;
for each of the ways, take this one "current" node and take the next node after it and the previous before it;
take the difference of GPS coordinates of current and next/previous node - you get two directions of the road;
of these several directions, take the one which has the direction closest to needed.
Thus, you can ask human to walk back if it seems that his destination is behind him. And no rerouting is needed because "route" is calculated incrementally.

It's no better than walking by Sun and compass, but it requires no complex algorithms, and can be done at night without moon and stars. For a pedestrian it will not be that bad; at least, it will not be a bee-line requiring to jump over fences.

Not all foot-walks are shown on a map, so no complex algorithm could give an ideal result; and this simplistic algorithm would often lead to "blind alleys" which turn out to be non-blind at all.

Of course, for driving with all traffic rules and jams, Google server is better suited. And for catching a bus.

Originally Posted by MartinK View Post
The OSM is being updated all the time, so some sort of update mechanism could be needed.
Just like for map tiles! But I can give an algorithm (human-readable and machine-breaking.
http://78.46.81.38/
1. Find a Wikipedia article about this place (suburb/street).
2. Take GPS coordinates from article and put them into "To which country belongs this location?".
3. In small XML file find the tag which includes the name of the place, and take its ID.
4. Put the ID into "Download an entire city".
You have the *.osm XML file with nodes, ways, relations, etc.

Originally Posted by MartinK View Post
It seems that both Gosmore and Routino work on N900 and could be theoretically interfaced with modRana.
Gosmore requires Diablo dependencies. Routino website www.routino.org cannot be found. I don't have patience to solve these problems right now.
Best luck to you! If you make ModRana use either of them, I will cheerfully attempt to test it.