More ways to define arcs

[Jesetens]

It would be really nice to have more option when making arcs.
Firstly, you could define the center of the arc in a similar way to how circles are made.
Secondly, you could define the start and end POINT instead of angle, which would really make some drawing easier.
Third, you could make an argument that takes a point and its location along the arc, this way you can do a lot of stuff like easily extending the arc.
Lastly, you could implement length as an argument that, well, tells Cetz how long the arc is. This is more niche but it could have uses in surface area problems or some technical drawings.

Basically what I'm requesting is new options for the arc:

1. center
2. start-point and end-point
3. trough-point( location(%) : , point(x,y,z) :)
4. length

I feel these would really change the game when it comes to drawing pictures with a lot of circles, curves and intersections in general.

[johannes-wolf]

1. Is possible by setting anchor: "origin"
2. start-point + end-point + radius?
3. There is arc-through which accepts 3 points, or do you need something different?
4. Length as delta: parameters? Example delta: 1cm or delta: 1.5?

[Jesetens]

Oh, I didn't know the anchor worked like that, my bad. As for the rest of these I'll go one by one:
2. Yes, currently I am trying to use arc-trough and guesstimate where the center of the arc would be but that is kinda tedious. This one would be the biggest game changer for me personally, it's the most intuitive way to make an arc in most cases. The best way to implement this is to add a radius option to arc-trough, so it would accept the same number of arguments and overall be mostly the same.
Edit: I did notice that only being given two points and the radius gives you 4 configuration for an arc, perhaps adding two arguments (one that determines the direction of the center and one that determines whether we want to draw the shorter or longer path between the points) but I'm just throwing out suggestions. maybe there is a better way to go around doing this.

3. To be fair there are better ways to achieve this so it's not really important. My though was to give the arc two points and let it figure out the third by telling it how far along the arc the second point is

4. Sure, that would work and be a minimal change.