Function angular_gradient_style 

pub fn angular_gradient_style(
    colors: &[Color],
    center: (f64, f64),
    start_degrees: f64,
) -> (Vec<u8>, *const c_void, *const c_void)

AngularGradient(gradient:center:angle:) — a sweep around a point.

The angle is where the sweep starts, in degrees; SwiftUI’s default is zero, which is what Swift’s own defaulted argument passes.