TF2 support without ROS dependencies
TF2 is widely used in robotics. DORA needs to have a ROS independent TF2 support.
Here are some research results and it seems feasible.
tf2 is designed to be ROS independent. The dependencies for the tf2 package are specifically limited. https://github.com/ros/geometry2/blob/indigo-devel/tf2/package.xml
<buildtool_depend version_gte="0.5.68">catkin</buildtool_depend>
<build_depend>libconsole-bridge-dev</build_depend> <build_depend>geometry_msgs</build_depend> <build_depend>rostime</build_depend> <build_depend>tf2_msgs</build_depend>
<run_depend>libconsole-bridge-dev</run_depend> <run_depend>geometry_msgs</run_depend> <run_depend>rostime</run_depend> <run_depend>tf2_msgs</run_depend>
Here are what's needed to pull it out as a pure library.
libconsole-bridge is a ROS independent console output library.
tf2_msgs is only used for error enumerations and can be replaced by copying the generated header file
geometry_msgs datatypes are used for data storage. A truely ros independent version would need to copy a few message header files or implement their own replacement data storage type.
rostime is the primative datatype for time in the above messages and is thus included
It uses the catkin cmake package which is technically independent of ROS and can be used if installed as a pure cmake package. If catkin is installed you can call (mkdir build && cd build && cmake .. && make)