FlightGear simulator support (#14539)

- Add flightgear_bridge submodule.
- Add traget px4_sitl_nolockstep with disabled  LOCKSTEP simulation.
- Add flightgear viewer targets and startup scripts
- Add a few possible vehicles plane (rascal), autogyro (tf-g1), and rover (tf-r1))

Co-authored-by: Vit Hanousek <vithanousek@seznam.cz>

platforms/posix/cmake/sitl_target.cmake

@@ -25,6 +25,7 @@ add_custom_target(run_config
 
 px4_add_git_submodule(TARGET git_gazebo PATH "${PX4_SOURCE_DIR}/Tools/sitl_gazebo")
 px4_add_git_submodule(TARGET git_jmavsim PATH "${PX4_SOURCE_DIR}/Tools/jMAVSim")
+px4_add_git_submodule(TARGET git_flightgear_bridge PATH "${PX4_SOURCE_DIR}/Tools/flightgear_bridge")
 
 # Add support for external project building
 include(ExternalProject)
@@ -57,6 +58,20 @@ ExternalProject_Add(mavsdk_tests
 	BUILD_ALWAYS 1
 )
 
+ExternalProject_Add(flightgear_bridge
+	SOURCE_DIR ${PX4_SOURCE_DIR}/Tools/flightgear_bridge
+	CMAKE_ARGS
+		-DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
+	BINARY_DIR ${PX4_BINARY_DIR}/build_flightgear_bridge
+	INSTALL_COMMAND ""
+	DEPENDS
+		git_flightgear_bridge
+	USES_TERMINAL_CONFIGURE true
+	USES_TERMINAL_BUILD true
+	EXCLUDE_FROM_ALL true
+	BUILD_ALWAYS 1
+)
+
 # create targets for each viewer/model/debugger combination
 set(viewers none jmavsim gazebo)
 set(debuggers none ide gdb lldb ddd valgrind callgrind)
@@ -146,6 +161,38 @@ foreach(viewer ${viewers})
 	endforeach()
 endforeach()
 
+#add flighgear targets
+if( ENABLE_LOCKSTEP_SCHEDULER STREQUAL "no")
+	set(models
+		rascal
+		rascal-electric
+		tf-g1
+		tf-r1
+		)
+	set(all_posix_vmd_make_targets)
+
+	foreach(model ${models})
+		set(_targ_name "flightgear_${model}")
+		add_custom_target(${_targ_name}
+			COMMAND ${PX4_SOURCE_DIR}/Tools/sitl_run.sh
+				$<TARGET_FILE:px4>
+				none
+				flightgear
+				${model}
+				none
+				${PX4_SOURCE_DIR}
+				${PX4_BINARY_DIR}
+			WORKING_DIRECTORY ${SITL_WORKING_DIR}
+			USES_TERMINAL
+			DEPENDS
+				logs_symlink
+			)
+
+		add_dependencies(${_targ_name} px4 flightgear_bridge)
+		list(APPEND all_posix_vmd_make_targets ${_targ_name})
+	endforeach()
+endif()
+
 string(REPLACE ";" "," posix_vmd_make_target_list "${all_posix_vmd_make_targets}")
 
 add_custom_target(list_vmd_make_targets