This is a tricky function that really needs a test around it.
Also it has several assumptions and traps:
- It will not work if the zones have multiple polygons in the poly sets
- It will not work if any polygon has line chains in a different order
- It is quadratic in number of zones and the compare itself is
superlinear (Simplify is called, evilly in a const function, which is
quadratic) and in a cyclic comparison, sort, which is presumably nlog-n
ish.
However, at least for the quadratic nature, profiling shows this to be
absolutely insignificant even for the VCU118 board.
John Beard
d5e129a3a0