Add the --suspend option to the JSBSim Python script.

python/JSBSim.py

@@ -49,6 +49,8 @@
  help="specifies to run at lower CPU usage")
 parser.add_argument("--nohighlight", default=False, action="store_true",
  help="specifies that console output should be pure text only (no color)")
+parser.add_argument("--suspend", default=False, action="store_true",
+ help="specifies to suspend the simulation after initialization")
 parser.add_argument("--initfile", metavar="<filename>",
  help="specifies an initialization file")
 parser.add_argument("--catalog", default=False, action="store_true",
@@ -185,17 +187,31 @@ def CheckXMLFile(f):
 current_seconds = initial_seconds = time.time()
 result = fdm.run()
 
-while result and fdm.get_sim_time() <= args.end:
- if args.realtime:
- current_seconds = time.time()
- actual_elapsed_time = current_seconds - initial_seconds
- sim_lag_time = actual_elapsed_time - fdm.get_sim_time()
+if args.suspend:
+ fdm.hold()
 
- for _ in range(int(sim_lag_time / frame_duration)):
- result = fdm.run()
- current_seconds = time.time()
- else:
+while result and fdm.get_sim_time() <= args.end:
+ fdm.check_incremental_hold()
+ if fdm.holding():
+ args.suspend = True
+ paused_seconds = time.time() - current_seconds
  result = fdm.run()
+ else:
+ if args.realtime:
+ if args.suspend:
+ initial_seconds += paused_seconds
+ args.suspend = False
+ current_seconds = time.time()
+ actual_elapsed_time = current_seconds - initial_seconds
+ sim_lag_time = actual_elapsed_time - fdm.get_sim_time()
+
+ for _ in range(int(sim_lag_time / frame_duration)):
+ result = fdm.run()
+ current_seconds = time.time()
+ if fdm.holding():
+ break
+ else:
+ result = fdm.run()
 
-  if args.nice:
-  time.sleep(sleep_nseconds / 1000000.0)
+ if args.nice:
+ time.sleep(sleep_nseconds / 1000000.0)