Function S2Loop.projectToBoundary

Return the closest point on the loop boundary to the given point. If the loop is empty or full, return the input argument (since the loop has no boundary). "x" should be unit length.

s2.util.math.vector.Vector!(double,3L) projectToBoundary (
  in const(s2.util.math.vector.Vector!(double,3L)) x
);