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use super::super::PointSequence;
use crate::geometry::Vector3;
use crate::{Float, PI};
pub struct CircumSeq {}
impl CircumSeq {
pub fn create(center: Vector3, normal: Vector3, radius: Float, n: usize) -> PointSequence {
let normal = normal.normalize();
let n1 = Self::get_orthogonal(&normal).normalize();
let n2 = normal.cross(&n1).normalize();
let mut control_points: Vec<Vector3> = Vec::with_capacity(n);
for i in 0..n {
let theta = 2.0 * PI / n as Float * i as Float;
let x = n1 * radius * theta.cos();
let y = n2 * radius * theta.sin();
control_points.push(center + x + y);
}
PointSequence::with_control_points(control_points)
}
fn get_orthogonal(v: &Vector3) -> Vector3 {
let mut a = Vector3::x();
if v.angle(&a) < PI / 2.0 {
a = Vector3::y();
}
v.cross(&a)
}
}