How to detect the intersection of a line and an arc？

[helloworld1l]

hi.
I use the Clipper2 like this:

clipper.AddClipOpen(paths);//save a arc
clipper.AddOpenSubject(pathsDetect);//save a line

PathsD open;
PolyPathD polyPath;

clipper.Execute(ClipType::Intersection, FillRule::NonZero, polyPath, open);
clipper.Clear();

Am I using this correctly?
：）

[AngusJohnson]

It looks fine. However, I suggest you avoid the PolyTreeD (PolyPathD) structure in favour of PathsD since there will be no closed paths in the solutions (given you're only intersecting with open paths).

[helloworld1l]

I wrote addclipOpen modeled after addclip like this:
void AddClipOpen(const PathsD& clips)
{
AddPaths(ScalePaths<int64_t, double>(clips, scale_, error_code_), PathType::Clip, true);
}

When I call the function like above, the content in "PathsD open" is empty,
but when I call "AddClip"，"PathsD open" contains two intersections.
Is this corret?
：）

[AngusJohnson]

Clip paths can't be open, only Subject paths.

The library supports open path clipping, though only subject paths may be open.
See: http://www.angusj.com/clipper2/Docs/Overview.htm#open_paths