code: float getLinearCurrentKeyframeProgress() {
      if (isDiscrete) {
        return 0f;
      }
  
      Keyframe<K> keyframe = getCurrentKeyframe();
      if (keyframe.isStatic()) {
        return 0f;
      }
      float progressIntoFrame = progress - keyframe.getStartProgress();
      float keyframeProgress = keyframe.getEndProgress() - keyframe.getStartProgress();
      return progressIntoFrame / keyframeProgress;
    }
docs: Returns the progress into the current keyframe between 0 and 1. This does not take into account
  any interpolation that the keyframe may have.