Partial offset

[esuig]

Hello,

Definitely among the best libraries around.

I have a question: is it possible to apply offset only to specific sections of a polygon, while the others remain unchanged (except for an extension or trim to get re-connected with the other portions depending on the offset being performed towards the outside or the inside of the polygon, of course)? Hope the following simple picture can help clarifying my question:

Many thanks

[alexisnaveros]

That's ambiguous, how do you want to decide what edges are being extended and by how much?

Perhaps you want to write your own version of clipper.offset.cpp, where you extend each edge as much as desired (or any other manipulation), then you call clipper.Execute(ClipType::Union, FillRule::Positive, ... ); or so, merging any overlap as a single shape.

[GromRGB]

Hello,

I have the same idea. We could give one point (find in the path) and 2 angles* to find all segments to offset.
For example:
paths = Clipper.InflatePaths(paths , 2, JoinType.Miter, EndType.Polygon, TopMostPt, 165, 195)
paths = Clipper.InflatePaths(paths , 3, JoinType.Miter, EndType.Polygon, RightMostPt, 89, 91)

The example of esuig can work with angles between -1 and 181.

*I use angle from the direction of the segment but it could be easier to use normal angle.

Regards