Border radius 2

[EliotRagueneau]

Associated issues:

• New edge type: smooth-segments #3201

• Previous PR: Border radius #3203

• This PR fix round-taxi edges which where sometime failing

• This PR fix the creation of loops with collinear points

• This PR adds a new property radius-type which impact how corner radius of edges are calculated and drawn.

  • The original type is now called arc-radius since with this type, the radius property is the radius of the corner arc. This is the deault type
  • The new type is called influence-radius since with this type, the radius is the one of the sphere of influence of the control point

Checklist

Author:

• The proper base branch has been selected. New features go on unstable. Bug-fix patches can go on either unstable or master.
• Automated tests have been included in this pull request, if possible, for the new feature(s) or bug fix. Check this box if tests are not pragmatically possible (e.g. rendering features could include screenshots or videos instead of automated tests).
• The associated GitHub issues are included (above).
• Notes have been included (above).

Reviewers:

• All automated checks are passing (green check next to latest commit).
• At least one reviewer has signed off on the pull request.
• For bug fixes: Just after this pull request is merged, it should be applied to both the master branch and the unstable branch. Normally, this just requires cherry-picking the corresponding merge commit from master to unstable -- or vice versa.

[maxkfranz]

@EliotRagueneau

Merged. I made the '.circle' nodes in your new demo such that they can't be grabbed and dragged by the user, since it feels strange: Moving the ordinary nodes updates things, but moving the '.circle' nodes does not. So, it doesn't make sense to allow the user to move them.

[EliotRagueneau]

Yes that's indeed a really good idea, I should have done it. Thanks for having added that!