mbostock/topojson — pull request #69 by mbostock (2013-05-11 22:12:22+00:00)
Title: Add presimplify and resimplify.

To facilitate interactive simplification, you can now call presimplify first,
which computes the effective area of each point. Then, you can call resimplify
to derive a filtered topology from the presimplified topology. This returns a
new object, and thus can be called repeatedly for fast interactive filtering.