Sketcher: OffsetInSketcher - Add BSpline and external geometry support

[gbulleryahen-hash]

OffsetInSketcher - v2.0

Extended version of the existing OffsetInSketcher macro with the following additions:

New features

• BSpline support : offset is computed via the Part API (makeOffset2D), the same method used by the CAM/Path workbench
• External geometry support : works with edges projected from other bodies/features (ExternalEdge), retrieved via ActiveSketch.ExternalGeometry
• Corner style choice : dialog now offers two options:
  • Sharp corner (Miter)
  • Rounded corner (Arc)

Technical notes

• All geometry (normal and external) is transformed into the sketch's local coordinate system before offset computation, ensuring correct results regardless of sketch orientation in 3D space
• Single unified code path via wire.makeOffset2D() for all geometry types
• Tested on FreeCAD 1.x

Compatibility

• Requires FreeCAD >= 0.19
• License: LGPL-2.0-or-later

sharp corner:

Rounded corner

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