Stable snap rounding
John E. Hershberger · 2011
Snap rounding is a popular method for rounding the vertices of a planar arrangement of line segments to the integer grid. It has many advantages, including minimum perturbation of the segments, preservation of the arrangement topology, and ease of implementation. However, snap rounding has one significant weakness: it is not stable (i.e., not idempotent). That is, applying snap rounding to a snap-rounded arrangement of n segments may cause additional segment perturbation, and the number of iterations of snap rounding needed to reach stability may be as large as Θ(n2).