mber.isRequired,
      simulateAnimation: PropTypes.func.isRequired,
      totalDuration: PropTypes.number.isRequired,
    };
  }

  render() {
    const {
      animation,
      durationPerPixel,
      keyframes,
      offset,
      simulateAnimation,
      totalDuration,
    } = this.props;

    const { state } = animation;
    const effectTiming = Object.assign({}, state, {
      fill: "both",
      iterations: state.iterationCount ? state.iterationCount : Infinity,
    });

    // Create new keyframes for opacity as computed style.
    // The reason why we use computed value instead of computed timing progress is to
    // include the easing in keyframes as well. Although the computed timing progress
    // is not affected by the easing in keyframes at all, computed value reflects that.
    const frames = keyframes.map(keyframe => {
      return {
        opacity: keyframe.offset,
        offset: keyframe.offset,
        easing: keyframe.easing,
      };
    });

    const simulatedAnimation = simulateAnimation(frames, effectTiming, true);

    if (!simulatedAnimation) {
      return null;
    }

    const simulatedElement = simulatedAnimation.effect.target;
    const win = simulatedElement.ownerGlobal;
    const endTime = simulatedAnimation.effect.getComputedTiming().endTime;

    // Set the underlying opacity to zero so that if we sample the animation's output
    // during the delay phase and it is not filling backwards, we get zero.
    simulatedElement.style.opacity = 0;

    const getValueFunc = time => {
      simulatedAnimation.currentTime = time;
      return win.getComputedStyle(simulatedElement).opacity;
    };

    const toPathStringFunc = createSummaryGraphPathStringFunction(
      endTime,
      state.playbackRate
    );
    const helper = new SummaryGraphHelper(
      state,
      keyframes,
      totalDuration,
      durationPerPixel,
      getValueFunc,
      toPathStringFunc
    );

    return dom.g(
      {
        className: this.getClassName(),
        transform: `translate(${offset})`,
      },
      this.renderGraph(state, helper)
    );
  }
}

module.exports = NegativePath;
PK