Streamline Angle API Behaviour

[johannes-wolf]

Angles are now always drawn counter-clock-wise.

Fixes #712

[knuesel]

Thanks! With that PR and the following code:

#let trig-angle(alpha) = cetz.canvas(length: 1.8cm, {
  import cetz.draw: *

  let O = (0, 0)
  let P = (1, 0)
  let Q = (alpha, 1)

  line(O, P, mark: (end: ">"))
  line(O, Q, mark: (end: ">"))
  content((P, -6pt, O), $P$)
  content((Q, -6pt, O), $Q$)

  cetz.angle.angle(O, P, Q, mark: (end: ">"), label: [#alpha], label-radius: 170%)
  rect((-1, 0), (1, 0), stroke: none) // for bounding box
})

#for alpha in (60deg, 240deg, -60deg, -240deg) {
  box(trig-angle(alpha))
}

I get this:

and if I add inner: false I get:

so the functionality is perfect for my use case.

I have two concerns though:

1. The keyword name inner doesn't make sense now
2. Other users might miss the previous functionality (having an easy way to choose between "short" and "long" path for the angle)

What about replacing inner with a direction keyword, with the following possible values:

• "clockwise"
• "counter-clockwise"
• "near"
• "far"

I think this way it would be easy to achieve the desired result in all common use cases. What do you think?

[johannes-wolf]

I've changed inner: to direction: with the values "cw" and "ccw".

[knuesel]

Excellent! I think that new API is great and something like "near"/"far" could be added later if there's demand for it.