AlexAegis/loreplotter

import { Vector3 } from 'three';

export const arcIntersection = (() => {
    const _c1 = new Vector3();
    const _c2 = new Vector3();
    const _i1 = new Vector3();
    const _i2 = new Vector3();
    const _mid = new Vector3();
    return (p1: Vector3, pe1: Vector3, p2: Vector3, pe2: Vector3): Vector3 => {
        _c1.copy(p1)
            .cross(pe1)
            .normalize();
        _c2.copy(p2)
            .cross(pe2)
            .normalize();
        _i1.copy(_c1)
            .cross(_c2)
            .normalize();
        _i2.copy(_c2)
            .cross(_c1)
            .normalize();
        _mid.copy(p1)
            .add(p2)
            .add(pe1)
            .add(pe2);
        return (_mid.dot(_i1) > 0 ? _i1 : _i2).normalize();
    };
})();