[Routing] Binary file format

[Adrian Stabiszewski]

> question:
> How would you go about zooming out?
> What would be the requirements to allow zooming out until
> you know where in a complete country or continent you are?

I think it should be possible to define min and max zoom levels. 

> I found this to be quite a problem with interactive rendering.
> (One small part of the screen may show Berlin with thousands of roads.)

You have to drop more and more minor roads while decreasing the zoom level.
We would have to test it. But don't think it is a good idea to use
pre-rendered tiles on mobile devices. 
Software like TomTom renders its maps very nicely and this is my reference
here ;)

> We would need a way to allow for level-of-details without storing things
> twice and without loading large numbers of tiles into memory just so we
> can get one way or node out of each one.
> 
> How would you go about ways that span tiles? Ways and areas that
> intesect tiles without having any node inside the tile?

Well, first you have to define tiles that are large enough. I'm thinking
about a tenth (0.1) of a degree in both directions atm. This would be
something like 11.1km in latitude direction and something like half of it in
longitude direction here in Europe.
Ways that span over several tiles would get additional nodes at the borders.
The same for the ways, that don't have any nodes inside a tile.

But this is all preliminary and work in progress ;)