advance method

Implementation

void advance(double deltaTime) {
  if (!playing || deltaTime <= 0) {
    return;
  }
  deltaTime *= playbackTimeScale;
  _playbackTime += deltaTime;

  // Handle looping behavior.

  if (_animation.endTime == 0) {
    _playbackTime = 0;
    return;
  }
  if (!loop && (_playbackTime < 0 || _playbackTime > _animation.endTime)) {
    // If looping is disabled, clamp to the end (or beginning, if playing in
    // reverse) and pause.
    pause();
    _playbackTime = clampDouble(_playbackTime, 0, _animation.endTime);
  } else if ( /* loop && */ _playbackTime > _animation.endTime) {
    // If looping is enabled and we ran off the end, loop to the beginning.
    _playbackTime = _playbackTime.abs() % _animation.endTime;
  } else if ( /* loop && */ _playbackTime < 0) {
    // If looping is enabled and we ran off the beginning, loop to the end.
    _playbackTime =
        _animation.endTime - (_playbackTime.abs() % _animation.endTime);
  }
}