sagitta property
final
How far the middle of a straight edge may sit from the curve it stands in for, in metres.
This is the whole subdivision rule, and it is stated as an error rather
than a step count because that is what it controls: the step needed to
hold a given sagitta is sqrt(8 ยท sagitta / curvature), so a hairpin gets
short segments and a straight gets long ones without anybody choosing a
number per corner. Four centimetres is well under a kerb.
Implementation
final double sagitta;