Source code for kxg.quickstart

#!/usr/bin/env python3

import linersock
import time, pyglet
import multiprocessing, queue
import logging, logging.handlers

from .errors import *
from .game import *
from .forums import Forum
from .multiplayer import ClientForum, ServerActor 

DEFAULT_HOST = 'localhost'

[docs]class Theater: """ Manage whichever stage is currently active. This involves both updating the current stage and handling transitions between stages. """
[docs] def __init__(self, initial_stage=None, gui=None): self._gui = gui self._initial_stage = initial_stage self._current_stage = None self._current_update = self._update_before_loop self._previous_time = time.time()
@property def gui(self): return self._gui @gui.setter def gui(self, gui): if self._current_stage: raise ApiUsageError("theater already playing; can't set gui.") self._gui = gui @property def initial_stage(self): return self._initial_stage @initial_stage.setter def initial_stage(self, stage): require_stage(stage) if self._current_stage: raise ApiUsageError("theater already playing; can't set initial stage.") self._initial_stage = stage @property def current_stage(self): return self._current_stage @property def is_finished(self): return self._current_update == self._update_after_loop
[docs] def update(self, dt=None): self._current_update(dt)
[docs] def exit(self): if self._current_stage: self._current_stage.on_exit_stage() self._current_update = self._update_after_loop
[docs] def _update_before_loop(self, dt): self._current_stage = self._initial_stage = self self._current_stage.on_enter_stage() self._current_update = self._update_main_loop self._current_update(dt)
[docs] def _update_main_loop(self, dt): if dt is None: current_time = time.time() dt = current_time - self._previous_time self._previous_time = current_time self._current_stage.on_update_stage(dt) if self._current_stage.is_finished: self._current_stage.on_exit_stage() self._current_stage = self._current_stage.successor if not self._current_stage: self.exit() else: require_stage(self._current_stage) = self self._current_stage.on_enter_stage()
[docs] def _update_after_loop(self, dt): raise AssertionError("shouldn't update the theater after the game has ended.")
[docs]class PygletTheater(Theater):
[docs] def play(self, frames_per_sec=50): pyglet.clock.schedule_interval(self.update, 1/frames_per_sec)
[docs] def exit(self): super().exit()
[docs]class Stage:
[docs] def __init__(self): = None self.successor = None self.is_finished = False
@property def gui(self): return
[docs] def exit_stage(self): """ Stop this stage from executing once the current update ends. """ self.is_finished = True
[docs] def exit_theater(self): """ Exit the game once the current update ends. """
[docs] def on_enter_stage(self): """ Give the stage a chance to set itself up before it is updated for the first time. """ pass
[docs] def on_update_stage(self, dt): """ Give the stage a chance to react to each clock cycle. The amount of time that passed since the last clock cycle is provided as an argument. """ pass
[docs] def on_exit_stage(self): """ Give the stage a chance to react before it is stopped and the next stage is started. You can define the next stage by setting the Stage.successor attribute. If the successor is static, you can just set it in the constructor. But if it will differ depending on the context, this method may be a good place to calculate it because it is called only once and just before the theater queries for the successor. """ pass
[docs]class GameStage(Stage):
[docs] def __init__(self, game): Stage.__init__(self) = game self.successor = None
[docs] def on_enter_stage(self): for actor in actor.on_setup_gui(self.gui)
[docs] def on_update_stage(self, dt): if self.exit_stage()
[docs] def on_exit_stage(self):
[docs]class ServerConnectionStage(Stage):
[docs] def __init__(self, world, referee, num_clients, ai_actors=None, host=DEFAULT_HOST, port=DEFAULT_PORT): super().__init__() = world self.referee = referee self.ai_actors = ai_actors or [] = host self.port = port self.pipes = [] self.greetings = [] self.server = linersock.Server( host, port, num_clients, self.on_clients_connected)
[docs] def on_enter_stage(self):
[docs] def on_update_stage(self, dt): if not self.server.finished(): self.server.accept() else: self.exit_stage()
[docs] def on_clients_connected(self, pipes): self.pipes += pipes
[docs] def on_exit_stage(self): self.successor = GameStage(MultiplayerServerGame(, self.referee, self.ai_actors, self.pipes))
[docs]class ClientConnectionStage(Stage):
[docs] def __init__(self, world, gui_actor, host, port): super().__init__() = world self.gui_actor = gui_actor = host self.port = port self.pipe = None self.client = linersock.Client( host, port, callback=self.on_connection_established)
[docs] def on_update_stage(self, dt): self.client.connect() try: self.gui.on_refresh_gui() except AttributeError: pass
[docs] def on_connection_established(self, pipe): self.pipe = pipe self.exit_stage()
[docs] def on_exit_stage(self): game_stage = ClientReceiveIdStage(, self.gui_actor, self.pipe) game_stage.successor.successor = PostgameSplashStage() self.successor = game_stage
[docs]class ClientReceiveIdStage(Stage):
[docs] def __init__(self, world, gui_actor, pipe): super().__init__() = MultiplayerClientGame(world, gui_actor, pipe) self.successor = GameStage(
[docs] def on_update_stage(self, dt): if self.exit_stage()
[docs]class PostgameSplashStage(Stage): """ Until the player closes the window, keep it as it was when the game ended. """
[docs] def on_update_stage(self, dt): try: self.gui.on_refresh_gui() except AttributeError: self.exit_stage()
[docs]class ProcessPool: """ Manage a group of processes running instances of the game loop. This class wraps around the basic multiprocessing functionality available in the python standard library. There are two nice features provided by this class. The first is that log messages generated in the subprocesses are automatically relayed to the main process, where they are reported with the name of the original process included and without any mangling due to race conditions. The second is that exceptions, which are usually silently ignored in subprocesses, are also relayed to the main process and re-raised. This class is actually not specific to the game engine at all, so in principle it could be moved into it's own library. I decided not to do that because I can't think of any other scenario where I would want the functionality that this class offers, but maybe I'll think of one later. """
[docs] def __init__(self, time_limit=None, frame_rate=30): self.log_queue = multiprocessing.Queue() self.exception_queue = multiprocessing.Queue() self.time_limit = time_limit self.elapsed_time = 0 self.frame_rate = frame_rate
[docs] def __enter__(self): return self
[docs] def __exit__(self, *args): self._run_supervisor()
[docs] def start(self, name, worker, *args, **kwargs): process = multiprocessing.Process( name=name, target=self._run_worker, args=(name, worker) + args, kwargs=kwargs, ) process.start()
[docs] def _run_worker(self, name, worker, *args, **kwargs): # Configure all logging message generated by this process to go into a # queue that will be read and handled by the supervisor. handler = logging.handlers.QueueHandler(self.log_queue) logging.root.addHandler(handler) # Catch any exceptions generated by the worker and report them to the # supervisor. This is important, because otherwise they would be # silently ignored. try: worker(*args, **kwargs) except Exception as exception: self.exception_queue.put_nowait(exception)
[docs] def _run_supervisor(self): """ Poll the queues that the worker can use to communicate with the supervisor, until all the workers are done and all the queues are empty. Handle messages as they appear. """ import time still_supervising = lambda: ( multiprocessing.active_children() or not self.log_queue.empty() or not self.exception_queue.empty()) try: while still_supervising(): # When a log message is received, make a logger with the same # name in this process and use it to re-log the message. It # will get handled in this process. try: record = self.log_queue.get_nowait() logger = logging.getLogger( logger.handle(record) except queue.Empty: pass # When an exception is received, immediately re-raise it. try: exception = self.exception_queue.get_nowait() except queue.Empty: pass else: raise exception # Sleep for a little bit, and make sure that the workers haven't # outlived their time limit. time.sleep(1/self.frame_rate) self.elapsed_time += 1/self.frame_rate if self.time_limit and self.elapsed_time > self.time_limit: raise RuntimeError("timeout") # Make sure the workers don't outlive the supervisor, no matter how the # polling loop ended (e.g. normal execution or an exception). finally: for process in multiprocessing.active_children(): process.terminate()
[docs]class MultiplayerDebugger: """ Simultaneously plays any number of different game theaters, executing each theater in its own process. This greatly facilitates the debugging and testing multiplayer games. """
[docs] def __init__(self, world_cls, referee_cls, gui_cls, gui_actor_cls, num_guis=2, ai_actor_cls=None, num_ais=0, theater_cls=PygletTheater, host=DEFAULT_HOST, port=DEFAULT_PORT, log_format= '%(levelname)s: %(processName)s: %(name)s: %(message)s'): # Members of this class have to be pickle-able, because this object # will be pickled and sent to every process that gets started. That's # why all the game objects are stored as classes (or factories) rather # than instances. Even though some of the game objects can be pickled, # none of them are meant to be and avoiding it reduces the risk that # things will break for strange reasons. The game objects themselves # are instantiated in the worker processes, which is how it would # happen if the user just rame multiple instances of the game anyway. self.theater_cls = theater_cls self.world_cls = world_cls self.referee_cls = referee_cls self.gui_cls = gui_cls self.gui_actor_cls = gui_actor_cls self.num_guis = num_guis self.ai_actor_cls = ai_actor_cls self.num_ais = num_ais = host self.port = port self.log_format = log_format
[docs] def play(self): # Configure the logging system to print to stderr and include the # process name in all of its messages. handler = logging.StreamHandler() formatter = logging.Formatter(self.log_format) handler.setFormatter(formatter) logging.root.addHandler(handler) # Run the server and the client (each in its own process). with ProcessPool() as pool: pool.start("Server", self.play_server) for i in range(self.num_guis): pool.start("Client #%d" % i, self.play_client)
[docs] def play_server(self): # Defer instantiation of all the game objects until we're inside our # own process, to avoid having to pickle and unpickle things that # shouldn't be pickled. theater = self.theater_cls() theater.initial_stage = ServerConnectionStage( world=self.world_cls(), referee=self.referee_cls(), num_clients=self.num_guis, ai_actors=[self.ai_actor_cls() for i in range(self.num_ais)],, port=self.port, )
[docs] def play_client(self): # Defer instantiation of all the game objects until we're inside our # own process, to avoid having to pickle and unpickle things that # should be pickled. theater = self.theater_cls() theater.gui = self.gui_cls() theater.initial_stage = ClientConnectionStage( world=self.world_cls(), gui_actor=self.gui_actor_cls(),, port=self.port, )
[docs]def main(world_cls, referee_cls, gui_cls, gui_actor_cls, ai_actor_cls, theater_cls=PygletTheater, default_host=DEFAULT_HOST, default_port=DEFAULT_PORT, argv=None): """ Run a game being developed with the kxg game engine. Usage: {exe_name} sandbox [<num_ais>] [-v...] {exe_name} client [--host HOST] [--port PORT] [-v...] {exe_name} server <num_guis> [<num_ais>] [--host HOST] [--port PORT] [-v...] {exe_name} debug <num_guis> [<num_ais>] [--host HOST] [--port PORT] [-v...] {exe_name} --help Commands: sandbox Play a single-player game with the specified number of AIs. None of the multiplayer machinery will be used. client Launch a client that will try to connect to a server on the given host and port. Once it connects and the game starts, the client will allow you to play the game against any other connected clients. server Launch a server that will manage a game between the given number of human and AI players. The human players must connect using this command's client mode. debug Debug a multiplayer game locally. This command launches a server and the given number of clients all in different processes, and configures the logging system such that the output from each process can be easily distinguished. Arguments: <num_guis> The number of human players that will be playing the game. Only needed by commands that will launch a multiplayer server. <num_ais> The number of AI players that will be playing the game. Only needed by commands that will launch a single-player game or a multiplayer server. Options: -x --host HOST [default: {default_host}] The address of the machine running the server. Must be accessible from the machines running the clients. -p --port PORT [default: {default_port}] The port that the server should listen on. Don't specify a value less than 1024 unless the server is running with root permissions. -v --verbose Have the game engine log more information about what it's doing. You can specify this option several times to get more and more information. This command is provided so that you can start writing your game with the least possible amount of boilerplate code. However, the clients and servers provided by this command are not capable of running a production game. Once you have written your game and want to give it a polished set of menus and options, you'll have to write your own main() function. The online documentation has more information on this process. """ import sys, os, docopt, nonstdlib exe_name = os.path.basename(sys.argv[0]) usage = main.__doc__.format(**locals()).strip() args = docopt.docopt(usage, argv or sys.argv[1:]) num_guis = int(args['<num_guis>'] or 1) num_ais = int(args['<num_ais>'] or 0) host, port = args['--host'], int(args['--port']) logging.basicConfig( format='%(levelname)s: %(name)s: %(message)s', level=nonstdlib.verbosity(args['--verbose']), ) # Use the given game objects and command line arguments to play a game! if args['debug']: print("""\ ****************************** KNOWN BUG WARNING ****************************** In debug mode, every message produced by the logging system gets printed twice. I know vaguely why this is happening, but as of yet I've not been able to fix it. In the mean time, don't let this confuse you! *******************************************************************************""") game = MultiplayerDebugger( world_cls, referee_cls, gui_cls, gui_actor_cls, num_guis, ai_actor_cls, num_ais, theater_cls, host, port) else: game = theater_cls() ai_actors = [ai_actor_cls() for i in range(num_ais)] if args['sandbox']: game.gui = gui_cls() game.initial_stage = GameStage(UniplayerGame( world_cls(), referee_cls(), gui_actor_cls(), ai_actors)) game.initial_stage.successor = PostgameSplashStage() if args['client']: game.gui = gui_cls() game.initial_stage = ClientConnectionStage( world_cls(), gui_actor_cls(), host, port) if args['server']: game.initial_stage = ServerConnectionStage( world_cls(), referee_cls(), num_guis, ai_actors, host, port)
[docs]def require_stage(object): require_instance(Stage(), object)