I'm trying to understand the source code of ArduPlane. The MAVLink message is decoded using a set of _MAV_RETURN_???? functions, e.g. _MAV_RETURN_float
When I grep recursively for _MAV_RETURN_float, I could not find where it is defined. I wonder if I'm missing anything.
UPDATE
Here is the source code of Ardupilot, including ArduPlane.
https://github.com/diydrones/ardupilot