Johann,
The merge lines patch is designed from start for high line numbers. It uses internal hashlists for performance reasons. I would expect the runtime to raise n*log(n), not n². So I do not expect it to burn cpu, but would need a test to proove it.
OK.
But I'm not sure, if merging across tiles would improve the whole thing. As far as I understand, a line could not go across multiple subdivisions. So it has to be splitted anyway at its bounds. I expect no usefull effects from merging before.
That's a good point, so it's probably not worth the effort to merge lines across subdivs.
What I really would like, is to apply the merge filter before any creating of routing data. This would be the most reasonable place with the most effect, even to routing quality.
That's true but it's non-trivial (as you know).
But one step after the other.... And I'm sorry, I could not spend that much time to the mkgamp project.
No problem. Are you happy with the current state of the merge patch? If so, I can commit it to trunk. Cheers, Mark