Function lyon::tessellation::math_utils::directed_angle

pub fn directed_angle(a: TypedPoint2D<f32, UnknownUnit>,
                      b: TypedPoint2D<f32, UnknownUnit>)
                      -> f32

Angle between vectors v1 and v2 (oriented clockwise assyming y points downwards). The result is a number between 0 and 2*PI.

ex: directed_angle([0,1], [1,0]) = 3/2 Pi rad x __ 0--> / \ y| | x--> v2 v \ |v1 v

Or, assuming y points upwards: directed_angle([0,-1], [1,0]) = 1/2 Pi rad

^ v2 y| x--> 0--> v1 | / x v-