PathKeyframeAnimation.java 文件源码

@Override public PointF getValue(Keyframe<PointF> keyframe, float keyframeProgress) {
  PathKeyframe pathKeyframe = (PathKeyframe) keyframe;
  Path path = pathKeyframe.getPath();
  if (path == null) {
    return keyframe.startValue;
  }

  if (pathMeasureKeyframe != pathKeyframe) {
    pathMeasure = new PathMeasure(path, false);
    pathMeasureKeyframe = pathKeyframe;
  }

  pathMeasure.getPosTan(keyframeProgress * pathMeasure.getLength(), pos, null);
  point.set(pos[0], pos[1]);
  return point;
}