fillet2D and chamfer2D in the fluent api

[marcus7070]

Now that #683 has added 2D fillets and chamfers in the direct API, should we expose it in the fluent API and can we do it neatly?

[marcus7070]

The major consideration for me is how do you fluently select which vertices to fillet/chamfer? Workplane.vertices() can't be used because the wire has not been extruded yet.

I think we can do a method with a signature like:

class Workplane:
    ...
    def fillet2D(
        self,
        radius: float,
        selector: Optional[Union[Selector, str]] = None,
        vertices: Optional[List[Vertex]] = None,
    ):

Outline of the method:

• consolidate pending edges and wires
• if vertices is not None:
  • fillet those vertices and return
• get all vertices from the pending wire
• if selector is not None:
  • filter all vertices by selector
• fillet vertices and return

Opinions? @adam-urbanczyk, would this implementation have any effect on #42?

[adam-urbanczyk]

Before going into API details, do we really need this op in the fluent API? For sure it has to be exposed in the (future) cq.Sketch API but I'd like to avoid reimplementing parts of cq.Sketch. Do you see yourself using it in the fluent API a lot?

[marcus7070]

Yeah, after thinking about it for a bit longer, this kind of stuff (selecting and operating on pending wires) will be core sketch API. I don't want to add a fluent API method only for it to be rendered redundant in forseeable future.