re why so many PIP checks - actually I don't think there are that many, relatively speaking. There are O(n+m) PIP checks, where n and m are the number of rings in the two geometries. In this case that is about 4300. That is a small number relative to the total number of vertices. And with the envelope test each PIP test is pretty fast, so this step probably doesn't take a very large percentage of the overall time. So indexing probably won't move the needle much here.
This would be worse for a pathological geometry with the same order of magnitude of holes as vertices (e.g. a Sierpinkski carpet [1]). And would be even worse for computing the intersection of two *nested* Sierpinksi carpets. But doubt that happens very often in the real world... :) [1] https://en.wikipedia.org/wiki/Sierpinski_carpet On Tue, Dec 4, 2018 at 4:29 PM Martin Davis <mtncl...@gmail.com> wrote: > It turns out that the SimplePointInAreaLocator envelope check has been in > place in JTS for quite a while. Guessed it got missed as a item to port. > > Still have to think about whether indexing would improve things. And I > don't see right now why there needs to be so many PIP checks at all, since > the hole assignment is known at the outset in this case. > > On Mon, Dec 3, 2018 at 1:40 PM Paul van der Linden < > paul.doskabou...@gmail.com> wrote: > >> Ok, first test with my big polygon and the envelope tests in place is >> giving a 27% speedup! >> >> >>
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