Specifies the function to be used for snap rounding.
DEFAULT: s2builderutil::IdentitySnapFunction(S1Angle::Zero())
[This does no snapping and preserves all input vertices exactly unless
there are crossing edges, in which case the snap radius is increased
to the maximum intersection point error (S2::kIntersectionError.]
Specifies the function to be used for snap rounding.
DEFAULT: s2builderutil::IdentitySnapFunction(S1Angle::Zero()) [This does no snapping and preserves all input vertices exactly unless there are crossing edges, in which case the snap radius is increased to the maximum intersection point error (S2::kIntersectionError.]