Add circle sector recipe

[JohannesNE]

Description

Adds recipe for creating a circle sector.
arc is used as template for this, but instead of many lines imitating an arc, it creates a filled path using BezierPath. (Using code modified from an example from @jkrumbiegel ).

Related to #3741. And solves the problem I initially wanted to use the offset pie for.

Example:

using CairoMakie
f = Figure() 
Axis(f[1, 1], aspect = DataAspect())

for i in 1:10
    sector!(Point2f(i, 0), 0.4, 0, 2π*i/10, inner_radius = 0.2)
end

f

(btw, is there a smart way to trim this figure, which is also in the docs?)

I'm quite new to Julia/Dev, so I have a few questions:

• Should I make a test for this, or are the examples in the docs enough?
• An If-else statement is used to draw a sector if inner_radius is 0 or a "fat" arc if inner_radius is > 0. Is there a smarter way to do this?

Type of change

• New feature (non-breaking change which adds functionality)

Checklist

• Added an entry in CHANGELOG.md (for new features and breaking changes)
• Added or changed relevant sections in the documentation
• Added unit tests for new algorithms, conversion methods, etc.
• Added reference image tests for new plotting functions, recipes, visual options, etc.

[jkrumbiegel]

Thanks for the PR! I feel like this is so similar to pie that it's a bit confusing to have both. It has a scatter-like signature in that the position is the first positional arg(s) but other than that, I think an array-enabled offset or position keyword for pie would do a similar thing, no?

[jkrumbiegel]

Hm although pie has this cumulative effect where one passes the fractions in order, maybe one would have to remodel that behavior a little then. So that one can pass array-valued offsets as well so it's start-stop for each?

[JohannesNE]

pie with a position argument could accomplish the same.

I made this a seperate recipe for two reasons.

1. In Add optional origin parameter to pie #3741 @SimonDanisch suggested making a separate recipe for making pie-scatters with a position argument, rather than add a position argument to pie.
2. It feels backwards to use a more complex function (pie) to generate a primitive (a circle sector).

We could update pie to use sector, so it draws actual circles rather than a high-vertex polygon.

[jkrumbiegel]

Ok I guess reusing it for pie internals makes more sense. Pie predates the bezier stuff, hence the vertices.

[JohannesNE]

Ok I guess reusing it for pie internals makes more sense. Pie predates the bezier stuff, hence the vertices.

But that is a separate PR right?, or should I try to include it in this?

[jkrumbiegel]

I would probably include it so you know whether your implementation is suitable for that purpose.

[jkrumbiegel]

If it's a scatter-like thing then I'd probably change the signature to PointLike style to match scatter, so only the positions as positional args (with the default conversions from the PointLike trait). And the other settings as attributes, accepting either scalar or vector

[JohannesNE]

Well, I did not consider whether it should be scatter-like or something else.
Really, I just wanted something similar to arc but drawing sectors, so it seemed simplest to just make it behave similar to arc.
Maybe it is more appropriate to add a Sector feature to GeometryBasics.jl and use poly, like for drawing a Circle or a Rect (thought I have no idea how to do that).