dataToPoint method

@override Offset? dataToPoint(covariant int axisIndex, covariant num data)

给定一个数据返回其对应数据在坐标系中的位置(视图位置为中心点)

Implementation

@override
Offset? dataToPoint(int axisIndex, num data) {
  RadarAxisNode? node = _axisMap[axisIndex];
  if (node == null) {
    return null;
  }
  double angle = node.props.end.offsetAngle(node.props.start);
  double r = node.dataToPoint(data);
  Offset offset = circlePoint(r, angle);
  return offset;
}