[Roadster] gps_tab

[Ian McIntosh]

Hi Bill,

> I had to unfix some GPS items in order to compile with gpsd 2.15... 
> before that I was segfaulting with gpsd 2.28 (from debian packages).

Someone else was having trouble with the new gpsd.  I think they traced
the crash to inside gpsd.  BUT they weren't having problems with other
apps using gpsd, so I don't really know where the problem is.

> Has this stuff been disabled (for the pre release?)

Yes.  Also, I no longer have a GPS receiver and I'm out of the US (no
road data here), so it's hard for me to work on it.

> I am trying to see what all has been done so I can pick something out to 
> help with.

All the GPS user-visible features need to be written or updated:

- Show on map
- Keep centered (or within a small circle to keep the # of redraws down)
- Draw trail (we will probably want line clipping for this!)
- Stick to roads

======

There is existing code in need of love:

- map_draw_cairo_road_label() in map_draw_cairo.c.  It's straight C and
some Cairo text drawing.

It's the code responsible for curved road labeling.  It's a bit long.
It could be broken up into the stages: 1. create possible draw spots, 2.
pick best, 3. draw.

======

If you like algorithms, you could write a polygon stitcher.  From TIGER,
we get a bunch of polygons that are touching on many points (but never
overlapping), and it would make sense to combine them into one.

It doesn't have to be fast or conserve memory, as it'll run during a
batch import process (and never on the user's PC).

Something like:

void map_math_stitch_touching_polygons(const GArray* pPoly1, const
GArray* pPoly2, GArray* pOutput);

pOutput will be an existing (but empty) GArray.

=====

Please let me know if you want more ideas or more info on one of these!

-Ian

[1] http://developer.gnome.org/doc/API//2.0/glib/glib-Arrays.html