3 point (poly)line offset

[juffe84]

I have a three point line. Clipper offsets it nicely on both sides, but loses the offset of point 2 because it is exactly on the same line as points 1 and 3.

How can I prevent this so that the points on the same line also offset? This is because I have a different Z value for the points.

And is it possible to offset only to the right or to the left?

[alexisnaveros]

You probably want clipperoffset.PreserveCollinear(1);

[juffe84]

Yes. Thank you! Maybe this is working. But is it possible to offset only to the right or to the left?

[alexisnaveros]

Not with the provided offset functions, but it's not hard to build your own.

You can just extend the edges as desired, or any other shape manipulation you desire, then call Clipper64 with:
c.Execute( ClipType::Union, FillRule::Positive, ... );

That'll merge all overlapping shapes as one big shape (FillRule::Positive: it's within the final shape if the local count of "overlaps" is positive).