2009/12/30 bulia byak <buliabyak@...400...>:
But a still better and more useful approach is to dedect a clockwise order, as I wrote before. This may not be always easy, but it's an interesting mathematical challenge. For example: calculate a center point of objects and rotate clockwise a ray from this center, and process objects in the order in which this ray crosses their bbox centers.
This is actually rather simple. Compute the center (this may require learning some not-perfectly-clear API); for each object calculate the vector from the center to that object's center (let's call it relpos) and sort on Geom::atan2(relpos), for example by inserting the SPItem*s into a std::map<double, SPItem*> and then iterating over it. I'm not sure whether it will produce a clockwise or a counterclockwise ordering, because I never remember which one (desktop / document) is the mathematical one :)
Regards, Krzysztof