@pnext/three-loader/src/utils/bounds.ts

Potree loader for ThreeJS, converted and adapted to Typescript.

import { Box3, Matrix4, Vector3 } from 'three';

/**
 * adapted from mhluska at https://github.com/mrdoob/three.js/issues/1561
 */
export function computeTransformedBoundingBox(box: Box3, transform: Matrix4): Box3 {
  return new Box3().setFromPoints([
    new Vector3(box.min.x, box.min.y, box.min.z).applyMatrix4(transform),
    new Vector3(box.min.x, box.min.y, box.min.z).applyMatrix4(transform),
    new Vector3(box.max.x, box.min.y, box.min.z).applyMatrix4(transform),
    new Vector3(box.min.x, box.max.y, box.min.z).applyMatrix4(transform),
    new Vector3(box.min.x, box.min.y, box.max.z).applyMatrix4(transform),
    new Vector3(box.min.x, box.max.y, box.max.z).applyMatrix4(transform),
    new Vector3(box.max.x, box.max.y, box.min.z).applyMatrix4(transform),
    new Vector3(box.max.x, box.min.y, box.max.z).applyMatrix4(transform),
    new Vector3(box.max.x, box.max.y, box.max.z).applyMatrix4(transform),
  ]);
}

export function createChildAABB(aabb: Box3, index: number): Box3 {
  const min = aabb.min.clone();
  const max = aabb.max.clone();
  const size = new Vector3().subVectors(max, min);

  // tslint:disable-next-line:no-bitwise
  if ((index & 0b0001) > 0) {
    min.z += size.z / 2;
  } else {
    max.z -= size.z / 2;
  }

  // tslint:disable-next-line:no-bitwise
  if ((index & 0b0010) > 0) {
    min.y += size.y / 2;
  } else {
    max.y -= size.y / 2;
  }

  // tslint:disable-next-line:no-bitwise
  if ((index & 0b0100) > 0) {
    min.x += size.x / 2;
  } else {
    max.x -= size.x / 2;
  }

  return new Box3(min, max);
}