Forces a vertex to be located at the given position. This can be used to
prevent certain input vertices from moving. However if you are trying to
preserve part of the input boundary, be aware that this option does not
prevent edges from being split by new vertices.
Forced vertices are never snapped; if this is desired then you need to
call options().snap_function().SnapPoint() explicitly. Forced vertices
are also never simplified away (if simplify_edge_chains() is used).
Caveat: Since this method can place vertices arbitrarily close together,
S2Builder makes no minimum separation guaranteees with forced vertices.
Forces a vertex to be located at the given position. This can be used to prevent certain input vertices from moving. However if you are trying to preserve part of the input boundary, be aware that this option does not prevent edges from being split by new vertices.
Forced vertices are never snapped; if this is desired then you need to call options().snap_function().SnapPoint() explicitly. Forced vertices are also never simplified away (if simplify_edge_chains() is used).
Caveat: Since this method can place vertices arbitrarily close together, S2Builder makes no minimum separation guaranteees with forced vertices.