QT内存映射读取点云数据

pcl::PointCloud::Ptr txtRead(std::string file_name)
{
	pcl::PointCloud::Ptr data(new pcl::PointCloud< pcl::PointXYZRGBA>);
	pcl::PointXYZRGBA f_xyz;
	QString str = QString::fromStdString(file_name);
	QFile file(str);
	if (!file.open(QFile::ReadOnly | QIODevice::Text))
		return 0;
	uchar* fpr = file.map(0, file.size());
	char *s = strdup((char*)fpr);
	char *substr;
	char *token = NULL;
	char *next = NULL;
	float point[3];
	while (substr = strtok_s(s,"\n", &next))
	{
		s = next;
		for (int i = 0; i < 3; i++)
		{
			char *lineSubStr = strtok_s(substr, " ", &token);
			substr = token;
			point[i] = atof(lineSubStr);
		}
		f_xyz.x = point[0];
		f_xyz.y = point[1];
		f_xyz.z = point[2];
		data->points.push_back(f_xyz);
	}
	file.close();
	data->height = data->points.size();
	data->width = 1;
	return data;
}