Weiler–Atherton clipping algorithm: Difference between revisions

Revision as of 05:36, 30 March 2017

Revision as of 05:37, 30 March 2017

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== Prelude ==

[[image:Weiler-Atherton subdivision.svg|thumb|upright=1.2|Subdivision with the Weiler-Atherton algorithm]]

Before applyingbeing applied to anya polygon, the algorithm requires several preconditions to be fulfilled:

* Candidate polygons need to be oriented clockwise.

* Candidate polygons should not be self -intersecting (i.e., re-entrant).

* The algorithm can support holes (as counter-clockwise polygons wholly inside their parent polygon), but requires additional algorithms to decide which polygons are holes. Then, after which merging of the polygons can be performed byusing a variant of the algorithm.

== The Algorithm ==