Le 21/06/2019 à 17:41, Jeff Young a écrit : > Question for you polygon folks: > > The old algorithm used to add a lot of pads to a “holes” polygon, then did a > Simplify() on it, and then a BooleanSubtract() from the filled area. > > The new code does a Simplify() and BooleanSubtract() per pad. Since the > holes are all discrete in either case (ie: not overlapping or otherwise > interacting with each other), I thought this would have similar performance, > and it makes the code easier to understand. But perhaps this is the source of > the performance issue? > > Cheers, > Jeff.
Operations between polygons use fast algorithms and AFAIK scan only once the full set of segments, and calculation time is something like N log N for N segments. (But I am not a polygon specialist) If you subtract holes by pad to the zone, the cost is N log N x pad count, with a value for N similar to the full segment count. Moreover Simplify() can be costly in calculation time (according to the Clipper doc). I always saw (when I tried this kind of calculations) the calculation time exploding, or at least much higher than a global calculation made only once. -- Jean-Pierre CHARRAS _______________________________________________ Mailing list: https://launchpad.net/~kicad-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~kicad-developers More help : https://help.launchpad.net/ListHelp
