[ gpsdrive ] breakthrough

[Hamish]

Hamish:
> with some hints from Tobias Sauerwein (OSGeo/Google Summer
> of Code student who just added webtile support for uDig GIS)
> I think we've finally cracked the OSM
> scale-varies-with-latitude problem.
> 
> This means that tiles made with gpsdrive_mapnik_gentiles
> actually seem to line up correctly! I'll adjust map_download.c
> for OSM at home and gpsfetchmap.pl ASAP. Previously the scale
> was badly wrong.

This is now done.

> Please move away your old .gpsdrive/maps/mapnik/ maps +
> map_koord.txt, generate new ones with
> gpsdrive_mapnik_gentiles.py, dig out your GPX tracks for
> overlays, and test test test!
>
> AFAIK everything is using the Google Mercator projection
> now, the old OSM merc projection is dead? (I am confused
> with the -m's) There may still be some slight distortion near
> the corners, and at country/global scales it will probably be
> bad, but those are limitations of the projection and nothing
> much we can do about it.
> 
> Anyway a coordinate from a maps.google.com URL Link now
> lines up with street maps, so I think it's all the right way
> around.


happy mapping,
Hamish