The greatArc class is the new name for greatCircle, which actually represents
great arcs. Meanwhile, a new greatCircle class is for great circles. The new
greatCircle class replaces the old clip class, providing clipping and resampling
functionality (using greatArc internally). This isn't backwards-compatible, but
I may forgo the major version number bump in light of the fact that greatCircle
was just added, and not used in any (official) examples or documented.
This can be used to process output from d3.geo.clip to ensure clipped
polygons are correctly curved.
The "n" option has been replaced with precision, which denotes the
approximate angular length of great-circle segments. This is much
faster than using a fixed number of segments, particularly when
processing a large number of polygons, only a few of which may have
edges long enough to warrant being converted into a geodesic.
This can be used with d3.geo.path.clip to clip the input coordinates of
geographical shapes using a given origin and angular radius, e.g. for
hemispherical or near-hemispherical views. Geodesics are inserted as
necessary.
This also includes a minor bugfix and test for d3.geo.path: the last
coordinate of Polygon features was being included unnecessarily
(MultiPolygon already handled this correctly).
This way, we don't need symlinks (which don't work on Windows). This commit also
simplifies the structure of the flare.json file, so that we don't need to tricky
conversion of the JSON map—it can be read directly by the hierarchy layout.