import { v3, Vec3 } from '../../math/Vec3';
import { DistanceResult, IntersectResult } from './result';

export class Segment extends Array {
  center: Vec3;
  extentDirection: Vec3;
  extentSqr: number;
  extent: number;
  direction: Vec3;
  normal: Vec3 | undefined;
  /**
   * 线段
   * @param  {Point|Vec3} p0
   * @param  {Point|Vec3} p1
   */
  constructor(_p0: Vec3 = v3(), _p1: Vec3 = v3()) {
    super();
    Object.setPrototypeOf(this, Segment.prototype);
    this.push(_p0, _p1);
    this.center = _p0.clone()
      .add(_p1)
      .multiplyScalar(0.5);
    this.extentDirection = _p1.clone().sub(_p0);
    this.extentSqr = this.extentDirection.lengthSq();
    this.extent = Math.sqrt(this.extentSqr);
    this.direction = this.extentDirection.clone().normalize();
  }

  get p0() {
    return this[0];
  }

  set p0(v: Vec3) {
    this[0].copy(v);
  }

  get p1() {
    return this[1];
  }

  set p1(v: Vec3) {
    this[1].copy(v);
  }
}


export function segment(p0: Vec3, p1: Vec3) {
  return new Segment(p0, p1);
}