@threeify/math/src/Spherical.Functions.ts

Computer graphics oriented, High performance, tree-shakeable, TypeScript 3D vector math library.

import { clamp } from './Functions.js';
import { Spherical } from './Spherical.js';
import { vec3Length } from './Vec3.Functions.js';
import { Vec3 } from './Vec3.js';

export function makeSphericalFromVec3(
  v: Vec3,
  result = new Spherical()
): Spherical {
  result.radius = vec3Length(v);

  if (result.radius === 0) {
    result.theta = 0;
    result.phi = 0;
  } else {
    result.theta = Math.atan2(v.x, v.z);
    result.phi = Math.acos(clamp(v.y / result.radius, -1, 1));
  }

  return result;
}