def save_to_json(sim, fname="sim"):
""" Saves a simulation's state as a .json file. """
fname = get_file_path(fname, "json")
with open(fname, 'w') as savefile:
# Collect all data to be saved
data = {"lifetime": sim.lifetime, "particles": list()}
# Go over each entity and save its properties
for e in sim.entities:
if issubclass(type(e), particle.ForceParticle):
try:
p_data = dict()
p_data["type"] = str(type(e))
p_data["pos"] = e.pos
p_data["velocity"] = e.velocity
p_data["mass"] = e.mass
p_data["size"] = e.size
p_data["can_move"] = e._can_move
p_data["paused"] = e.paused
data["particles"].append(p_data)
except AttributeError as e:
Logger.log_warning(
"Corrupt particle. Can't save particle.")
Logger.log_exception(e)
continue
# Dump data to json
json.dump(data, savefile)
def create_particle(data):
""" Accepts data and creates particle according to it. """
# Get particle type
type_raw = None
try:
type_raw = data["type"]
except KeyError as ke:
Logger.log_warning("No particle type data. Can't spawn particle.")
Logger.log_exception(ke)
return None
t = type_raw
if type(type_raw) is str:
# Get actual class reference
t = get_particle_type(type_raw)
if t is None:
Logger.log_warning("Unrecognized particle type. Can't spawn particle.")
return None
# Construct particle
p = None
try:
pos = data["pos"]
p = t(pos[0], pos[1])
except KeyError as ke:
Logger.log_warning("Incomplete particle data. Can't spawn particle.")
Logger.log_exception(ke)
return None
# Set particle attributes
try:
p.mass = data["mass"]
p.velocity = data["velocity"]
p.size = data["size"]
p._can_move = data["can_move"]
p.paused = data["paused"]
except KeyError as ke:
Logger.log_info("Missing particle data.")
Logger.log_exception(ke)
return p
