Allow Copter to compile when Fence is disable but Avoidance is not

[peterbarker]

This arose out of a previous PR - #26466 IIRC.

There hasn't been a technical requirement for this for some time..

Also expanded the tool used to test this sort of change to build_options.py

. The important ouputs were:

pbarker@fx:~/rc/ardupilot(pr/avoidance-no-fence2)$ cat /tmp/enable-in-turn.csv 
Feature,antennatracker,blimp,copter,plane,rover,sub
AP_AVOIDANCE_ENABLED,-56,-64,-8368,0,-4680,-3944
AP_FENCE_ENABLED,-10320,-10464,-30440,-14144,-28204,-12336
pbarker@fx:~/rc/ardupilot(pr/avoidance-no-fence2)$ cat /tmp/some.csv 
Feature,antennatracker,blimp,copter,plane,rover,sub
AP_AVOIDANCE_ENABLED,56,56,11208,-40,8704,7352
AP_FENCE_ENABLED,2688,2816,41624,14072,35508,19656

[rmackay9]

Thanks for this. This is a good idea but we should test in SITL that simple avoidance in Loiter mode works using only proximity sensors.

[rmackay9]

I tested this and maybe I did something wrong but it seems like setting AP_FENCE_ENABLED definition to zero led to AC_Avoidance library disappearing. the AVOID_xxx parameters disappeared.

This is the command line I used
../Tools/autotest/sim_vehicle.py -A --serial5=sim:rplidara2 -l 51.8752066,14.6487840,54.15,0 --map --console --configure-define="AP_FENCE_ENABLED=0"

Just for reference, instructions for testing with proximity sensors in SITL are here: https://ardupilot.org/dev/docs/adding_simulated_devices.html#adding-a-360deg-lidar

[peterbarker]

I've added a patch so that we don't disable avoidance if fence is disabled. Missed that patch somehow.

[rmackay9]

Maybe we should change this so it's (AP_FENCE_ENABLE || HAL_PROXIMITY_ENABLED || AP_BEACON_ENABLED). No point in having avoidance if none of these are available.

[peterbarker]

I can see if this works - but this sort of thing usually ends up with include loops / tears.