Function _initTween

esm/gsap-core.js:2849–3023

(tween, time, tTime)

    //store a reference temporarily so we can avoid overwriting itself.
_forceAllPropTweens,
    _initTween = function _initTween(tween, time, tTime) {
  var vars = tween.vars,
      ease = vars.ease,
      startAt = vars.startAt,
      immediateRender = vars.immediateRender,
      lazy = vars.lazy,
      onUpdate = vars.onUpdate,
      runBackwards = vars.runBackwards,
      yoyoEase = vars.yoyoEase,
      keyframes = vars.keyframes,
      autoRevert = vars.autoRevert,
      dur = tween._dur,
      prevStartAt = tween._startAt,
      targets = tween._targets,
      parent = tween.parent,
      fullTargets = parent && parent.data === "nested" ? parent.vars.targets : targets,
      autoOverwrite = tween._overwrite === "auto" && !_suppressOverwrites,
      tl = tween.timeline,
      reverseEase = vars.easeReverse || yoyoEase,
      cleanVars,
      i,
      p,
      pt,
      target,
      hasPriority,
      gsData,
      harness,
      plugin,
      ptLookup,
      index,
      harnessVars,
      overwritten;
  tl && (!keyframes || !ease) && (ease = "none");
  tween._ease = _parseEase(ease, _defaults.ease);
  tween._rEase = reverseEase && (_parseEase(reverseEase) || tween._ease);
  tween._from = !tl && !!vars.runBackwards; //nested timelines should never run backwards - the backwards-ness is in the child tweens.

  if (tween._from) tween.ratio = 1;

  if (!tl || keyframes && !vars.stagger) {
    //if there's an internal timeline, skip all the parsing because we passed that task down the chain.
    harness = targets[0] ? _getCache(targets[0]).harness : 0;
    harnessVars = harness && vars[harness.prop]; //someone may need to specify CSS-specific values AND non-CSS values, like if the element has an "x" property plus it's a standard DOM element. We allow people to distinguish by wrapping plugin-specific stuff in a css:{} object for example.

    cleanVars = _copyExcluding(vars, _reservedProps);

    if (prevStartAt) {
      prevStartAt._zTime < 0 && prevStartAt.progress(1); // in case it's a lazy startAt that hasn't rendered yet.

      time < 0 && runBackwards && immediateRender && !autoRevert ? prevStartAt.render(-1, true) : prevStartAt.revert(runBackwards && dur ? _revertConfigNoKill : _startAtRevertConfig); // if it's a "startAt" (not "from()" or runBackwards: true), we only need to do a shallow revert (keep transforms cached in CSSPlugin)
      // don't just _removeFromParent(prevStartAt.render(-1, true)) because that'll leave inline styles. We're creating a new _startAt for "startAt" tweens that re-capture things to ensure that if the pre-tween values changed since the tween was created, they're recorded.

      prevStartAt._lazy = 0;
    }

    if (startAt) {
      _removeFromParent(tween._startAt = Tween.set(targets, _setDefaults({
        data: "isStart",