CODEWITHSUNDEEP
2dpolygonclipping
Evan Prodromou
Evan Prodromou

Reputation: 31

With the Weiler-Atherton clipping algorithm what do I do with collinear segments?

I'm trying to implement a Weiler-Atherton clipping algorithm. I've read around a lot, and looked at sample code, and I can't seem to find anyone who talks about collinear line segments and how to deal with them.

For example, the two rectangles
[[0, 0], [0, 1], [3, 1], [3, 0]] and [[1, 0], [1, 2], [2, 2], [2, 0]]
have two overlapping line segments --[[3, 0], [0, 0]] overlaps with [[2, 0], [1, 0]].

Most code I've read will treat these as parallel line segments and leaves out the intersection completely. Is that the best thing to do?

Upvotes: 1

Views: 852

Answers (1)

Evan Prodromou
Evan Prodromou

Reputation: 31

So, right now, I think the answer is "ignore them". The two vertices of the overlap will also be intersections of other (non-colinear) line segments, so you can just handle them when dealing with those intersections.

Upvotes: 1

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