pacman.py

# pacman.py
# ---------
# Licensing Information: Please do not distribute or publish solutions to this
# project. You are free to use and extend these projects for educational
# purposes. The Pacman AI projects were developed at UC Berkeley, primarily by
# John DeNero (denero@cs.berkeley.edu) and Dan Klein (klein@cs.berkeley.edu).
# For more info, see http://inst.eecs.berkeley.edu/~cs188/sp09/pacman.html

"""
Pacman.py holds the logic for the classic pacman game along with the main
code to run a game.  This file is divided into three sections:

  (i)  Your interface to the pacman world:
          Pacman is a complex environment.  You probably don't want to
          read through all of the code we wrote to make the game runs
          correctly.  This section contains the parts of the code
          that you will need to understand in order to complete the
          project.  There is also some code in game.py that you should
          understand.

  (ii)  The hidden secrets of pacman:
          This section contains all of the logic code that the pacman
          environment uses to decide who can move where, who dies when
          things collide, etc.  You shouldn't need to read this section
          of code, but you can if you want.

  (iii) Framework to start a game:
          The final section contains the code for reading the command
          you use to set up the game, then starting up a new game, along with
          linking in all the external parts (agent functions, graphics).
          Check this section out to see all the options available to you.

To play your first game, type 'python pacman.py' from the command line.
The keys are 'a', 's', 'd', and 'w' to move (or arrow keys).  Have fun!
"""
from game import GameStateData
from game import Game
from game import Directions
from game import Actions
from util import nearestPoint
from util import manhattanDistance
import util, layout
import sys, types, time, random, os

###################################################
# YOUR INTERFACE TO THE PACMAN WORLD: A GameState #
###################################################

class GameState:
  """
  A GameState specifies the full game state, including the food, capsules,
  agent configurations and score changes.

  GameStates are used by the Game object to capture the actual state of the game and
  can be used by agents to reason about the game.

  Much of the information in a GameState is stored in a GameStateData object.  We
  strongly suggest that you access that data via the accessor methods below rather
  than referring to the GameStateData object directly.

  Note that in classic Pacman, Pacman is always agent 0.
  """

  ####################################################
  # Accessor methods: use these to access state data #
  ####################################################

  def getLegalActions( self, agentIndex=0 ):
    """
    Returns the legal actions for the agent specified.
    """
    if self.isWin() or self.isLose(): return []

    if agentIndex == 0:  # Pacman is moving
      return PacmanRules.getLegalActions( self )
    else:
      return GhostRules.getLegalActions( self, agentIndex )

  def generateSuccessor( self, agentIndex, action):
    """
    Returns the successor state after the specified agent takes the action.
    """
    # Check that successors exist
    if self.isWin() or self.isLose(): raise Exception('Can\'t generate a successor of a terminal state.')

    # Copy current state
    state = GameState(self)

    # Let agent's logic deal with its action's effects on the board
    if agentIndex == 0:  # Pacman is moving
      state.data._eaten = [False for i in range(state.getNumAgents())]
      PacmanRules.applyAction( state, action )
    else:                # A ghost is moving
      GhostRules.applyAction( state, action, agentIndex )

    # Time passes
    if agentIndex == 0:
      state.data.scoreChange += -TIME_PENALTY # Penalty for waiting around
    else:
      GhostRules.decrementTimer( state.data.agentStates[agentIndex] )

    # Resolve multi-agent effects
    GhostRules.checkDeath( state, agentIndex )

    # Book keeping
    state.data._agentMoved = agentIndex
    state.data.score += state.data.scoreChange
    #print(state.data.score)
    return state

  def getLegalPacmanActions( self ):
    return self.getLegalActions( 0 )

  def generatePacmanSuccessor( self, action ):
    """
    Generates the successor state after the specified pacman move
    """
    return self.generateSuccessor( 0, action )

  def getPacmanState( self ):
    """
    Returns an AgentState object for pacman (in game.py)

    state.pos gives the current position
    state.direction gives the travel vector
    """
    return self.data.agentStates[0].copy()

  def getPacmanPosition( self ):
    return self.data.agentStates[0].getPosition()

  def getGhostStates( self ):
    return self.data.agentStates[1:]

  def getGhostState( self, agentIndex ):
    if agentIndex == 0 or agentIndex >= self.getNumAgents():
      raise Exception("Invalid index passed to getGhostState")
    return self.data.agentStates[agentIndex]

  def getGhostPosition( self, agentIndex ):
    if agentIndex == 0:
      raise Exception("Pacman's index passed to getGhostPosition")
    return self.data.agentStates[agentIndex].getPosition()

  def getGhostPositions(self):
    return [s.getPosition() for s in self.getGhostStates()]

  def getNumAgents( self ):
    return len( self.data.agentStates )

  def getScore( self ):
    return self.data.score

  def getCapsules(self):
    """
    Returns a list of positions (x,y) of the remaining capsules.
    """
    return self.data.capsules

  def getNumFood( self ):
    return self.data.food.count()

  def getFood(self):
    """
    Returns a Grid of boolean food indicator variables.

    Grids can be accessed via list notation, so to check
    if there is food at (x,y), just call

    currentFood = state.getFood()
    if currentFood[x][y] == True: ...
    """
    return self.data.food

  def getWalls(self):
    """
    Returns a Grid of boolean wall indicator variables.

    Grids can be accessed via list notation, so to check
    if there is food at (x,y), just call

    walls = state.getWalls()
    if walls[x][y] == True: ...
    """
    return self.data.layout.walls

  def hasFood(self, x, y):
    return self.data.food[x][y]

  def hasWall(self, x, y):
    return self.data.layout.walls[x][y]

  def isLose( self ):
    return self.data._lose

  def isWin( self ):
    return self.data._win

  #############################################
  #             Helper methods:               #
  # You shouldn't need to call these directly #
  #############################################

  def __init__( self, prevState = None ):
    """
    Generates a new state by copying information from its predecessor.
    """
    if prevState != None: # Initial state
      self.data = GameStateData(prevState.data)
    else:
      self.data = GameStateData()

  def deepCopy( self ):
    state = GameState( self )
    state.data = self.data.deepCopy()
    return state

  def __eq__( self, other ):
    """
    Allows two states to be compared.
    """
    if other is None:
      return False
    return self.data == other.data

  def __hash__( self ):
    """
    Allows states to be keys of dictionaries.
    """
    return hash( self.data )

  def __str__( self ):

    return str(self.data)

  def initialize( self, layout, numGhostAgents=1000 ):
    """
    Creates an initial game state from a layout array (see layout.py).
    """
    self.data.initialize(layout, numGhostAgents)

############################################################################
#                     THE HIDDEN SECRETS OF PACMAN                         #
#                                                                          #
# You shouldn't need to look through the code in this section of the file. #
############################################################################

SCARED_TIME = 40    # Moves ghosts are scared
COLLISION_TOLERANCE = 0.7 # How close ghosts must be to Pacman to kill
TIME_PENALTY = 1 # Number of points lost each round

class ClassicGameRules:
  """
  These game rules manage the control flow of a game, deciding when
  and how the game starts and ends.
  """
  def __init__(self, timeout=30):
    self.timeout = timeout

  def newGame( self, layout, pacmanAgent, ghostAgents, display, quiet = False, catchExceptions=False):
    agents = [pacmanAgent] + ghostAgents[:layout.getNumGhosts()]
    initState = GameState()
    initState.initialize( layout, len(ghostAgents) )
    game = Game(agents, display, self, catchExceptions=catchExceptions)
    game.state = initState
    self.initialState = initState.deepCopy()
    self.quiet = quiet
    return game

  def process(self, state, game):
    """
    Checks to see whether it is time to end the game.
    """
    if state.isWin(): self.win(state, game)
    if state.isLose(): self.lose(state, game)

  def win( self, state, game ):
    if not self.quiet: print("Pacman emerges victorious! Score: %d" % state.data.score)
    game.gameOver = True

  def lose( self, state, game ):
    if not self.quiet: print("Pacman died! Score: %d" % state.data.score)
    game.gameOver = True

  def getProgress(self, game):
    return float(game.state.getNumFood()) / self.initialState.getNumFood()

  def agentCrash(self, game, agentIndex):
    if agentIndex == 0:
      print("Pacman crashed")
    else:
      print("A ghost crashed")

  def getMaxTotalTime(self, agentIndex):
    return self.timeout

  def getMaxStartupTime(self, agentIndex):
    return self.timeout

  def getMoveWarningTime(self, agentIndex):
    return self.timeout

  def getMoveTimeout(self, agentIndex):
    return self.timeout

  def getMaxTimeWarnings(self, agentIndex):
    return 0

class PacmanRules:
  """
  These functions govern how pacman interacts with his environment under
  the classic game rules.
  """
  PACMAN_SPEED=1

  def getLegalActions( state ):
    """
    Returns a list of possible actions.
    """
    return Actions.getPossibleActions( state.getPacmanState().configuration, state.data.layout.walls )
  getLegalActions = staticmethod( getLegalActions )

  def applyAction( state, action ):
    """
    Edits the state to reflect the results of the action.
    """
    legal = PacmanRules.getLegalActions( state )
    if action not in legal:
      raise Exception("Illegal action " + str(action))

    pacmanState = state.data.agentStates[0]

    # Update Configuration
    vector = Actions.directionToVector( action, PacmanRules.PACMAN_SPEED )
    pacmanState.configuration = pacmanState.configuration.generateSuccessor( vector )

    # Eat
    next = pacmanState.configuration.getPosition()
    nearest = nearestPoint( next )
    if manhattanDistance( nearest, next ) <= 0.5 :
      # Remove food
      PacmanRules.consume( nearest, state )
  applyAction = staticmethod( applyAction )

  def consume( position, state ):
    x,y = position
    # Eat food
    if state.data.food[x][y]:
      state.data.scoreChange += 10
      state.data.food = state.data.food.copy()
      state.data.food[x][y] = False
      state.data._foodEaten = position
      # TODO: cache numFood?
      numFood = state.getNumFood()
      if numFood == 0 and not state.data._lose:
        state.data.scoreChange += 500
        state.data._win = True
    # Eat capsule
    if( position in state.getCapsules() ):
      state.data.capsules.remove( position )
      state.data._capsuleEaten = position
      # Reset all ghosts' scared timers
      for index in range( 1, len( state.data.agentStates ) ):
        state.data.agentStates[index].scaredTimer = SCARED_TIME
  consume = staticmethod( consume )

class GhostRules:
  """
  These functions dictate how ghosts interact with their environment.
  """
  GHOST_SPEED=1.0
  def getLegalActions( state, ghostIndex ):
    """
    Ghosts cannot stop, and cannot turn around unless they
    reach a dead end, but can turn 90 degrees at intersections.
    """
    conf = state.getGhostState( ghostIndex ).configuration
    possibleActions = Actions.getPossibleActions( conf, state.data.layout.walls )
    reverse = Actions.reverseDirection( conf.direction )
    if Directions.STOP in possibleActions:
      possibleActions.remove( Directions.STOP )
    if reverse in possibleActions and len( possibleActions ) > 1:
      possibleActions.remove( reverse )
    return possibleActions
  getLegalActions = staticmethod( getLegalActions )

  def applyAction( state, action, ghostIndex):

    legal = GhostRules.getLegalActions( state, ghostIndex )
    if action not in legal:
      raise Exception("Illegal ghost action " + str(action))

    ghostState = state.data.agentStates[ghostIndex]
    speed = GhostRules.GHOST_SPEED
    if ghostState.scaredTimer > 0: speed /= 2.0
    vector = Actions.directionToVector( action, speed )
    ghostState.configuration = ghostState.configuration.generateSuccessor( vector )
  applyAction = staticmethod( applyAction )

  def decrementTimer( ghostState):
    timer = ghostState.scaredTimer
    if timer == 1:
      ghostState.configuration.pos = nearestPoint( ghostState.configuration.pos )
    ghostState.scaredTimer = max( 0, timer - 1 )
  decrementTimer = staticmethod( decrementTimer )

  def checkDeath( state, agentIndex):
    pacmanPosition = state.getPacmanPosition()
    if agentIndex == 0: # Pacman just moved; Anyone can kill him
      for index in range( 1, len( state.data.agentStates ) ):
        ghostState = state.data.agentStates[index]
        ghostPosition = ghostState.configuration.getPosition()
        if GhostRules.canKill( pacmanPosition, ghostPosition ):
          GhostRules.collide( state, ghostState, index )
    else:
      ghostState = state.data.agentStates[agentIndex]
      ghostPosition = ghostState.configuration.getPosition()
      if GhostRules.canKill( pacmanPosition, ghostPosition ):
        GhostRules.collide( state, ghostState, agentIndex )
  checkDeath = staticmethod( checkDeath )

  def collide( state, ghostState, agentIndex):
    if ghostState.scaredTimer > 0:
      state.data.scoreChange += 200
      GhostRules.placeGhost(state, ghostState)
      ghostState.scaredTimer = 0
      # Added for first-person
      state.data._eaten[agentIndex] = True
    else:
      if not state.data._win:
        state.data.scoreChange -= 500
        state.data._lose = True
  collide = staticmethod( collide )

  def canKill( pacmanPosition, ghostPosition ):
    return manhattanDistance( ghostPosition, pacmanPosition ) <= COLLISION_TOLERANCE
  canKill = staticmethod( canKill )

  def placeGhost(state, ghostState):
    ghostState.configuration = ghostState.start
  placeGhost = staticmethod( placeGhost )

#############################
# FRAMEWORK TO START A GAME #
#############################

def default(str):
  return str + ' [Default: %default]'

def parseAgentArgs(str):
  if str == None: return {}
  pieces = str.split(',')
  opts = {}
  for p in pieces:
    if '=' in p:
      key, val = p.split('=')
    else:
      key,val = p, 1
    opts[key] = val
  return opts

def readCommand( argv ):
  """
  Processes the command used to run pacman from the command line.
  """
  from optparse import OptionParser
  usageStr = """
  USAGE:      python pacman.py <options>
  EXAMPLES:   (1) python pacman.py
                  - starts an interactive game
              (2) python pacman.py --layout smallClassic --zoom 2
              OR  python pacman.py -l smallClassic -z 2
                  - starts an interactive game on a smaller board, zoomed in
  """
  parser = OptionParser(usageStr)

  parser.add_option('-n', '--numGames', dest='numGames', type='int',
                    help=default('the number of GAMES to play'), metavar='GAMES', default=1)
  parser.add_option('-l', '--layout', dest='layout',
                    help=default('the LAYOUT_FILE from which to load the map layout'),
                    metavar='LAYOUT_FILE', default='mediumClassic')
  parser.add_option('-p', '--pacman', dest='pacman',
                    help=default('the agent TYPE in the pacmanAgents module to use'),
                    metavar='TYPE', default='KeyboardAgent')
  parser.add_option('-t', '--textGraphics', action='store_true', dest='textGraphics',
                    help='Display output as text only', default=False)
  parser.add_option('-q', '--quietTextGraphics', action='store_true', dest='quietGraphics',
                    help='Generate minimal output and no graphics', default=False)
  parser.add_option('-g', '--ghosts', dest='ghost',
                    help=default('the ghost agent TYPE in the ghostAgents module to use'),
                    metavar = 'TYPE', default='RandomGhost')
  parser.add_option('-k', '--numghosts', type='int', dest='numGhosts',
                    help=default('The maximum number of ghosts to use'), default=4)
  parser.add_option('-z', '--zoom', type='float', dest='zoom',
                    help=default('Zoom the size of the graphics window'), default=1.0)
  parser.add_option('-f', '--fixRandomSeed', action='store_true', dest='fixRandomSeed',
                    help='Fixes the random seed to always play the same game', default=False)
  parser.add_option('-r', '--recordActions', action='store_true', dest='record',
                    help='Writes game histories to a file (named by the time they were played)', default=False)
  parser.add_option('--replay', dest='gameToReplay',
                    help='A recorded game file (pickle) to replay', default=None)
  parser.add_option('-a','--agentArgs',dest='agentArgs',
                    help='Comma separated values sent to agent. e.g. "opt1=val1,opt2,opt3=val3"')
  parser.add_option('-x', '--numTraining', dest='numTraining', type='int',
                    help=default('How many episodes are training (suppresses output)'), default=0)
  parser.add_option('--frameTime', dest='frameTime', type='float',
                    help=default('Time to delay between frames; <0 means keyboard'), default=0.1)
  parser.add_option('-c', '--catchExceptions', action='store_true', dest='catchExceptions', 
                    help='Turns on exception handling and timeouts during games', default=False)
  parser.add_option('--timeout', dest='timeout', type='int',
                    help=default('Maximum length of time an agent can spend computing in a single game'), default=30)

  options, otherjunk = parser.parse_args(argv)
  if len(otherjunk) != 0:
    raise Exception('Command line input not understood: ' + str(otherjunk))
  args = dict()

  # Fix the random seed
  if options.fixRandomSeed: random.seed('cs188')

  # Choose a layout
  args['layout'] = layout.getLayout( options.layout )
  if args['layout'] == None: raise Exception("The layout " + options.layout + " cannot be found")

  # Choose a Pacman agent
  noKeyboard = options.gameToReplay == None and (options.textGraphics or options.quietGraphics)
  pacmanType = loadAgent(options.pacman, noKeyboard)
  agentOpts = parseAgentArgs(options.agentArgs)
  if options.numTraining > 0:
    args['numTraining'] = options.numTraining
    if 'numTraining' not in agentOpts: agentOpts['numTraining'] = options.numTraining
  pacman = pacmanType(**agentOpts) # Instantiate Pacman with agentArgs
  args['pacman'] = pacman

  # Don't display training games
  if 'numTrain' in agentOpts:
    options.numQuiet = int(agentOpts['numTrain'])
    options.numIgnore = int(agentOpts['numTrain'])

  # Choose a ghost agent
  ghostType = loadAgent(options.ghost, noKeyboard)
  args['ghosts'] = [ghostType( i+1 ) for i in range( options.numGhosts )]

  # Choose a display format
  if options.quietGraphics:
      import textDisplay
      args['display'] = textDisplay.NullGraphics()
  elif options.textGraphics:
    import textDisplay
    textDisplay.SLEEP_TIME = options.frameTime
    args['display'] = textDisplay.PacmanGraphics()
  else:
    import graphicsDisplay
    args['display'] = graphicsDisplay.PacmanGraphics(options.zoom, frameTime = options.frameTime)
  args['numGames'] = options.numGames
  args['record'] = options.record
  args['catchExceptions'] = options.catchExceptions
  args['timeout'] = options.timeout

  # Special case: recorded games don't use the runGames method or args structure
  if options.gameToReplay != None:
    print('Replaying recorded game %s.' % options.gameToReplay)
    import cPickle
    f = open(options.gameToReplay)
    try: recorded = cPickle.load(f)
    finally: f.close()
    recorded['display'] = args['display']
    replayGame(**recorded)
    sys.exit(0)

  return args

def loadAgent(pacman, nographics):
  # Looks through all pythonPath Directories for the right module,
  pythonPathStr = os.path.expandvars("$PYTHONPATH")
  if pythonPathStr.find(';') == -1:
    pythonPathDirs = pythonPathStr.split(':')
  else:
    pythonPathDirs = pythonPathStr.split(';')
  pythonPathDirs.append('.')

  for moduleDir in pythonPathDirs:
    if not os.path.isdir(moduleDir): continue
    moduleNames = [f for f in os.listdir(moduleDir) if f.endswith('gents.py')]
    for modulename in moduleNames:
      try:
        module = __import__(modulename[:-3])
      except ImportError:
        continue
      if pacman in dir(module):
        if nographics and modulename == 'keyboardAgents.py':
          raise Exception('Using the keyboard requires graphics (not text display)')
        return getattr(module, pacman)
  raise Exception('The agent ' + pacman + ' is not specified in any *Agents.py.')

def replayGame( layout, actions, display ):
    import pacmanAgents, ghostAgents
    rules = ClassicGameRules()
    agents = [pacmanAgents.GreedyAgent()] + [ghostAgents.RandomGhost(i+1) for i in range(layout.getNumGhosts())]
    game = rules.newGame( layout, agents[0], agents[1:], display )
    state = game.state
    display.initialize(state.data)

    for action in actions:
      # Execute the action
      state = state.generateSuccessor( *action )
      # Change the display
      display.update( state.data )
      # Allow for game specific conditions (winning, losing, etc.)
      rules.process(state, game)

    display.finish()

def runGames( layout, pacman, ghosts, display, numGames, record, numTraining = 0, catchExceptions=False, timeout=30 ):
  import __main__
  __main__.__dict__['_display'] = display

  rules = ClassicGameRules(timeout)
  games = []

  for i in range( numGames ):
    beQuiet = i < numTraining
    if beQuiet:
        # Suppress output and graphics
        import textDisplay
        gameDisplay = textDisplay.NullGraphics()
        rules.quiet = True
    else:
        gameDisplay = display
        rules.quiet = False
    game = rules.newGame( layout, pacman, ghosts, gameDisplay, beQuiet, catchExceptions)
    game.run()
    if not beQuiet: games.append(game)

    if record:
      import time, cPickle
      fname = ('recorded-game-%d' % (i + 1)) +  '-'.join([str(t) for t in time.localtime()[1:6]])
      f = file(fname, 'w')
      components = {'layout': layout, 'actions': game.moveHistory}
      cPickle.dump(components, f)
      f.close()

  if (numGames-numTraining) > 0:
    scores = [game.state.getScore() for game in games]
    wins = [game.state.isWin() for game in games]
    winRate = wins.count(True)/ float(len(wins))
    print('Average Score:', sum(scores) / float(len(scores)))
    print('Scores:       ', ', '.join([str(score) for score in scores]))
    print('Win Rate:      %d/%d (%.2f)' % (wins.count(True), len(wins), winRate))
    print('Record:       ', ', '.join([ ['Loss', 'Win'][int(w)] for w in wins]))

  return games

if __name__ == '__main__':
  """
  The main function called when pacman.py is run
  from the command line:

  > python pacman.py

  See the usage string for more details.

  > python pacman.py --help
  """
  args = readCommand( sys.argv[1:] ) # Get game components based on input
  runGames( **args )

  # import cProfile
  # cProfile.run("runGames( **args )")
  pass