Why is focal length defined as a single variable ?

[fbasatemur]

Hi, according to the source code of the libgazebo_camera plugin, I need to define a single focal length value for setting camera intrinsic parameters. Can I set these values separately for fx and fy, using different values for each?

gazebo_ros_pkgs/gazebo_plugins/src/gazebo_ros_camera_utils.cpp

Line 558 in 98bb3d0

camera_info_msg.K[0] = this->focal_length_;

gazebo_ros_pkgs/gazebo_plugins/src/gazebo_ros_camera_utils.cpp

Line 562 in 98bb3d0

camera_info_msg.K[4] = this->focal_length_;