Clean up simple_gui.py

examples/simple_gui.py

@@ -1,26 +1,31 @@
 #!/usr/bin/python3
 """
-Simple GUI example TODO: Docs
+Simple GUI example that prints the latitude and longitude of the aircraft
 """
 import time
+import math
 from flightgear_python.fg_if import GuiConnection
 
 def gui_callback(gui_data, event_pipe):
-    print(gui_data)
-    return gui_data
+    lat_deg = math.degrees(gui_data['lat_rad'])
+    lon_deg = math.degrees(gui_data['lon_rad'])
+    child_data = (lat_deg, lon_deg)
+    event_pipe.child_send(child_data)
 
 """
 Start FlightGear with `--native-gui=socket,out,30,localhost,5504,udp --native-gui=socket,in,30,localhost,5505,udp`
 """
 if __name__ == '__main__':  # NOTE: This is REQUIRED on Windows!
     gui_conn = GuiConnection(gui_version=8)
-    ctrls_event_pipe = gui_conn.connect_rx('localhost', 5504, gui_callback)
-    gui_conn.connect_tx('localhost', 5505)
-    gui_conn.start()  # Start the GUI RX/TX loop
+    gui_event_pipe = gui_conn.connect_rx('localhost', 5504, gui_callback)
+    # Note: I couldn't get FlightGear to do anything with the returned data on this interface
+    # I think it's just ignoring everything. Technically you can send data back though.
+    # gui_conn.connect_tx('localhost', 5505)
+    gui_conn.start()  # Start the GUI RX loop
 
-    time.sleep(2)
     while True:
-        # could also do `gui_conn.event_pipe.parent_send` so you just need to pass around `gui_conn`
-        # ctrls_event_pipe.parent_send((gear_down_parent,))  # send tuple
-        # gear_down_parent = not gear_down_parent  # Flip gear state
-        time.sleep(10)
+        # could also do `gui_conn.event_pipe.parent_recv` so you just need to pass around `gui_conn`
+        pipe_data = gui_event_pipe.parent_recv()  # receive tuple
+        lat_deg, lon_deg = pipe_data
+        print(f'Lat: {lat_deg:.6f} Lon: {lon_deg:.6f}')
+        time.sleep(0.01)