ts/src/utils/pos.js

import { lineString, bezierSpline } from '@turf/turf'

export function cartesian32LonLat(cartesian3) {
  const cartographic =
    viewer.scene.globe.ellipsoid.cartesianToCartographic(cartesian3)

  const lat = Cesium.Math.toDegrees(cartographic.latitude)

  const lon = Cesium.Math.toDegrees(cartographic.longitude)
  const height = cartographic.height
  return [lon, lat, height]
}

export function getPositionFromTime(
  startTime,
  pos,
  totalAnimationTime,
  interval = 100
) {
  const points = []

  for (let i = 0; i <= totalAnimationTime / interval; i++) {
    const time = Cesium.JulianDate.addSeconds(
      startTime,
      i,
      new Cesium.JulianDate()
    )
    const point = pos.getValue(time)
    point && points.push(point)
  }

  return points
}

export function getBezierSpline(points) {
  return bezierSpline(lineString(points))
}