Flattens the ways from OpenStreetMap XML into datamaps format.
$ curl -O https://s3.amazonaws.com/metro-extracts.mapzen.com/indianapolis.osm.bz2
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 15.7M 100 15.7M 0 0 1321k 0 0:00:12 0:00:12 --:--:-- 1394k
$ make
cc -g -Wall -O3 -o snap snap.c -lexpat
$ bzcat indianapolis.osm.bz2 | ./snap | ../datamaps/encode -z20 -o indianapolis.dm
...
Sorting 1 shapes of 7 point(s), zoom level 22
Sorting part 1 of 1
Sorting 1 shapes of 3 point(s), zoom level 28
Sorting part 1 of 1
Sorting 1 shapes of 7 point(s), zoom level 23
Sorting part 1 of 1
Merging: 100%
$ ../datamaps/render indianapolis.dm 14 4271 6210 > broadripple.png
