flappy.py

from itertools import cycle
import random
import sys
import qlearning

import pygame
from pygame.locals import *

FPS = 100
SCREENWIDTH  = 288
SCREENHEIGHT = 512
# amount by which base can maximum shift to left
PIPEGAPSIZE  = 100 # gap between upper and lower part of pipe
BASEY        = SCREENHEIGHT * 0.79
# image, sound and hitmask  dicts
IMAGES, SOUNDS, HITMASKS = {}, {}, {}

# list of all possible players (tuple of 3 positions of flap)
PLAYERS_LIST = (
    # red bird
    (
        'assets/sprites/redbird-upflap.png',
        'assets/sprites/redbird-midflap.png',
        'assets/sprites/redbird-downflap.png',
    ),
    # blue bird
    (
        # amount by which base can maximum shift to left
        'assets/sprites/bluebird-upflap.png',
        'assets/sprites/bluebird-midflap.png',
        'assets/sprites/bluebird-downflap.png',
    ),
    # yellow bird
    (
        'assets/sprites/yellowbird-upflap.png',
        'assets/sprites/yellowbird-midflap.png',
        'assets/sprites/yellowbird-downflap.png',
    ),
)

# list of backgrounds
BACKGROUNDS_LIST = (
    'assets/sprites/background-day.png',
    'assets/sprites/background-night.png',
)

# list of pipes
PIPES_LIST = (
    'assets/sprites/pipe-green.png',
    'assets/sprites/pipe-red.png',
)


try:
    xrange
except NameError:
    xrange = range


def main():
    global SCREEN, FPSCLOCK
    pygame.init()
    FPSCLOCK = pygame.time.Clock()
    SCREEN = pygame.display.set_mode((SCREENWIDTH, SCREENHEIGHT))
    pygame.display.set_caption('Flappy Bird')

    # numbers sprites for score display
    IMAGES['numbers'] = (
        pygame.image.load('assets/sprites/0.png').convert_alpha(),
        pygame.image.load('assets/sprites/1.png').convert_alpha(),
        pygame.image.load('assets/sprites/2.png').convert_alpha(),
        pygame.image.load('assets/sprites/3.png').convert_alpha(),
        pygame.image.load('assets/sprites/4.png').convert_alpha(),
        pygame.image.load('assets/sprites/5.png').convert_alpha(),
        pygame.image.load('assets/sprites/6.png').convert_alpha(),
        pygame.image.load('assets/sprites/7.png').convert_alpha(),
        pygame.image.load('assets/sprites/8.png').convert_alpha(),
        pygame.image.load('assets/sprites/9.png').convert_alpha()
    )

    # game over sprite
    IMAGES['gameover'] = pygame.image.load('assets/sprites/gameover.png').convert_alpha()
    # message sprite for welcome screen
    IMAGES['message'] = pygame.image.load('assets/sprites/message.png').convert_alpha()
    # base (ground) sprite
    IMAGES['base'] = pygame.image.load('assets/sprites/base.png').convert_alpha()

    # sounds
    if 'win' in sys.platform:
        soundExt = '.wav'
    else:
        soundExt = '.ogg'

    SOUNDS['die']    = pygame.mixer.Sound('assets/audio/die' + soundExt)
    SOUNDS['hit']    = pygame.mixer.Sound('assets/audio/hit' + soundExt)
    SOUNDS['point']  = pygame.mixer.Sound('assets/audio/point' + soundExt)
    SOUNDS['swoosh'] = pygame.mixer.Sound('assets/audio/swoosh' + soundExt)
    SOUNDS['wing']   = pygame.mixer.Sound('assets/audio/wing' + soundExt)

    # learning statistics
    # TODO: add file for top score and perhaps some more if wanted
    numIterations = 0

    while True:
        # Load in previous qvalues if exists, otherwise init new q-table
        qvalues = qlearning.load_q()

        # select random background sprites
        randBg = random.randint(0, len(BACKGROUNDS_LIST) - 1)
        IMAGES['background'] = pygame.image.load(BACKGROUNDS_LIST[randBg]).convert()

        # select random player sprites
        randPlayer = random.randint(0, len(PLAYERS_LIST) - 1)
        IMAGES['player'] = (
            pygame.image.load(PLAYERS_LIST[randPlayer][0]).convert_alpha(),
            pygame.image.load(PLAYERS_LIST[randPlayer][1]).convert_alpha(),
            pygame.image.load(PLAYERS_LIST[randPlayer][2]).convert_alpha(),
        )

        # select random pipe sprites
        pipeindex = random.randint(0, len(PIPES_LIST) - 1)
        IMAGES['pipe'] = (
            pygame.transform.rotate(
                pygame.image.load(PIPES_LIST[pipeindex]).convert_alpha(), 180),
            pygame.image.load(PIPES_LIST[pipeindex]).convert_alpha(),
        )

        # hismask for pipes
        HITMASKS['pipe'] = (
            getHitmask(IMAGES['pipe'][0]),
            getHitmask(IMAGES['pipe'][1]),
        )

        # hitmask for player
        HITMASKS['player'] = (
            getHitmask(IMAGES['player'][0]),
            getHitmask(IMAGES['player'][1]),
            getHitmask(IMAGES['player'][2]),
        )

        movementInfo = initialization()
        mainGame(movementInfo, qvalues)
        numIterations += 1
        # TODO: save numIterations to file
        print(numIterations)


def initialization():
    """Prepares all correct positions of sprites"""
    # index of player to blit on screen
    playerIndex = 0
    playerIndexGen = cycle([0, 1, 2, 1])
    playerx = int(SCREENWIDTH * 0.2)
    playery = int((SCREENHEIGHT - IMAGES['player'][0].get_height()) / 2)

    basex = 0
    # amount by which base can maximum shift to left
    baseShift = IMAGES['base'].get_width() - IMAGES['background'].get_width()
    # Get current Q-values or initalize new if mno exits
    # TODO: save computed Q-values!
    #qvalues = qlearning.init_q()

    return {
        'playery': playery,
        'playerx': playerx,
        'basex': basex,
        'playerIndexGen': playerIndexGen,
    } 

def mainGame(movementInfo, qvalues):
    score = playerIndex = loopIter = 0
    playerIndexGen = movementInfo['playerIndexGen']
    playerx, playery = movementInfo['playerx'], movementInfo['playery']

    basex = movementInfo['basex']
    baseShift = IMAGES['base'].get_width() - IMAGES['background'].get_width()

    # get 2 new pipes to add to upperPipes lowerPipes list
    newPipe1 = getRandomPipe()
    newPipe2 = getRandomPipe()

    # list of upper pipes
    upperPipes = [
        {'x': SCREENWIDTH + 200, 'y': newPipe1[0]['y']},
        {'x': SCREENWIDTH + 200 + (SCREENWIDTH / 2), 'y': newPipe2[0]['y']},
    ]

    # list of lowerpipe
    lowerPipes = [
        {'x': SCREENWIDTH + 200, 'y': newPipe1[1]['y']},
        {'x': SCREENWIDTH + 200 + (SCREENWIDTH / 2), 'y': newPipe2[1]['y']},
    ]

    pipeVelX = -4

    # player velocity, max veloc, downward acc, acc. on flap
    playerVelY    =  -9   # player's velo. along Y, default is playerFlapped
    playerMaxVelY =  10   # max vel along Y, max descend speed
    playerMinVelY =  -8   # min vel along Y, max ascend speed
    playerAccY    =   1   # players downward accleration
    playerRot     =  45   # player's rotation
    playerVelRot  =   3   # angular speed
    playerRotThr  =  20   # rotation threshold
    playerFlapAcc =  -9   # players speed on flapping
    playerFlapped = False # True when player flaps

    while True:
        # the game always has two pipes ready
        # check if bird is beyond first pipe
        if lowerPipes[0]['x'] - playerx > -30:
            currentPipe = lowerPipes[0]
        else:
            currentPipe = lowerPipes[1]

        for event in pygame.event.get():
            # do nothing for the events
            pass

        # observe current state
        dx = currentPipe['x'] - playerx
        dy = currentPipe['y'] - playery
        current_state_hash = qlearning.map_to_state(dx, dy)

        # take an action
        action = qlearning.select_action(current_state_hash, qvalues)
        if action == qlearning.JUMP:
            if playery > -2 * IMAGES['player'][0].get_height():
                playerVelY = playerFlapAcc
                playerFlapped = True
                SOUNDS['wing'].play()

        # check for crash here
        crashTest = checkCrash(
            {'x': playerx, 'y': playery, 'index': playerIndex}, 
            upperPipes, lowerPipes
        )

        # observe reward
        if crashTest[0]:
            reward = -1000
            qlearning.save_q(qvalues)
        else:
            reward = 1
         
        # check for score
        playerMidPos = playerx + IMAGES['player'][0].get_width() / 2
        for pipe in upperPipes:
            pipeMidPos = pipe['x'] + IMAGES['pipe'][0].get_width() / 2
            if pipeMidPos <= playerMidPos < pipeMidPos + 4:
                score += 1
                SOUNDS['point'].play()

        # playerIndex basex change
        if (loopIter + 1) % 3 == 0:
            playerIndex = next(playerIndexGen)
        loopIter = (loopIter + 1) % 30
        basex = -((-basex + 100) % baseShift)

        # rotate the player
        if playerRot > -90:
            playerRot -= playerVelRot

        # player's movement
        if playerVelY < playerMaxVelY and not playerFlapped:
            playerVelY += playerAccY
        if playerFlapped:
            playerFlapped = False

            # more rotation to cover the threshold (calculated in visible rotation)
            playerRot = 45

        playerHeight = IMAGES['player'][playerIndex].get_height()
        playery += min(playerVelY, BASEY - playery - playerHeight)

        # move pipes to left
        for uPipe, lPipe in zip(upperPipes, lowerPipes):
            uPipe['x'] += pipeVelX
            lPipe['x'] += pipeVelX

        # add new pipe when first pipe is about to touch left of screen
        if 0 < upperPipes[0]['x'] < 5:
            newPipe = getRandomPipe()
            upperPipes.append(newPipe[0])
            lowerPipes.append(newPipe[1])

        # remove first pipe if its out of the screen
        if upperPipes[0]['x'] < -IMAGES['pipe'][0].get_width():
            upperPipes.pop(0)
            lowerPipes.pop(0)

        # draw sprites
        SCREEN.blit(IMAGES['background'], (0,0))

        for uPipe, lPipe in zip(upperPipes, lowerPipes):
            SCREEN.blit(IMAGES['pipe'][0], (uPipe['x'], uPipe['y']))
            SCREEN.blit(IMAGES['pipe'][1], (lPipe['x'], lPipe['y']))

        SCREEN.blit(IMAGES['base'], (basex, BASEY))
        # print score so player overlaps the score
        showScore(score)

        # Player rotation has a threshold
        visibleRot = playerRotThr
        if playerRot <= playerRotThr:
            visibleRot = playerRot
        
        playerSurface = pygame.transform.rotate(IMAGES['player'][playerIndex], visibleRot)
        SCREEN.blit(playerSurface, (playerx, playery))

        # select correct pipes to compare distance to
        if lowerPipes[0]['x'] - playerx > -30:
            currentPipe = lowerPipes[0]
        else:
            currentPipe = lowerPipes[1]

        # observe new state
        dx = currentPipe['x'] - playerx
        dy = currentPipe['y'] - playery
        new_state_hash = qlearning.map_to_state(dx, dy)

        # update q values
        update_ok = qlearning.update_qval(qvalues, current_state_hash,
            new_state_hash, action, reward)
        if not update_ok:
            print("ERROR: could not q value for current state " +
                current_state_hash + " and new state " + new_state_hash)

        # end game if crashed in the new state
        # otherwise continue and commit game updates
        if crashTest[0]:
            # TODO: 
            # save q-values and score!
            return {
                'y': playery,
                'groundCrash': crashTest[1],
                'basex': basex,
                'upperPipes': upperPipes,
                'lowerPipes': lowerPipes,
                'score': score,
                'playerVelY': playerVelY,
                'playerRot': playerRot
            }
        else:
            pygame.display.update()
            FPSCLOCK.tick(FPS)

def playerShm(playerShm):
    """oscillates the value of playerShm['val'] between 8 and -8"""
    if abs(playerShm['val']) == 8:
        playerShm['dir'] *= -1

    if playerShm['dir'] == 1:
         playerShm['val'] += 1
    else:
        playerShm['val'] -= 1


def getRandomPipe():
    """returns a randomly generated pipe"""
    # y of gap between upper and lower pipe
    gapY = random.randrange(0, int(BASEY * 0.6 - PIPEGAPSIZE))
    gapY += int(BASEY * 0.2)
    pipeHeight = IMAGES['pipe'][0].get_height()
    pipeX = SCREENWIDTH + 10
    lowerPipeY = gapY + PIPEGAPSIZE
    upperPipeY = gapY - pipeHeight

    return [
        {'x': pipeX, 'y': upperPipeY},  # upper pipe
        {'x': pipeX, 'y': lowerPipeY}, # lower pipe
    ]


def showScore(score):
    """displays score in center of screen"""
    scoreDigits = [int(x) for x in list(str(score))]
    totalWidth = 0 # total width of all numbers to be printed

    for digit in scoreDigits:
        totalWidth += IMAGES['numbers'][digit].get_width()

    Xoffset = (SCREENWIDTH - totalWidth) / 2

    for digit in scoreDigits:
        SCREEN.blit(IMAGES['numbers'][digit], (Xoffset, SCREENHEIGHT * 0.1))
        Xoffset += IMAGES['numbers'][digit].get_width()


def checkCrash(player, upperPipes, lowerPipes):
    """returns True if player collders with base or pipes."""
    pi = player['index']
    player['w'] = IMAGES['player'][0].get_width()
    player['h'] = IMAGES['player'][0].get_height()

    # if player crashes into ground
    if player['y'] + player['h'] >= BASEY - 1:
        return [True, True]
    else:

        playerRect = pygame.Rect(player['x'], player['y'],
                      player['w'], player['h'])
        pipeW = IMAGES['pipe'][0].get_width()
        pipeH = IMAGES['pipe'][0].get_height()

        for uPipe, lPipe in zip(upperPipes, lowerPipes):
            # upper and lower pipe rects
            uPipeRect = pygame.Rect(uPipe['x'], uPipe['y'], pipeW, pipeH)
            lPipeRect = pygame.Rect(lPipe['x'], lPipe['y'], pipeW, pipeH)

            # player and upper/lower pipe hitmasks
            pHitMask = HITMASKS['player'][pi]
            uHitmask = HITMASKS['pipe'][0]
            lHitmask = HITMASKS['pipe'][1]

            # if bird collided with upipe or lpipe
            uCollide = pixelCollision(playerRect, uPipeRect, pHitMask, uHitmask)
            lCollide = pixelCollision(playerRect, lPipeRect, pHitMask, lHitmask)

            if uCollide or lCollide:
                return [True, False]

    return [False, False]

def pixelCollision(rect1, rect2, hitmask1, hitmask2):
    """Checks if two objects collide and not just their rects"""
    rect = rect1.clip(rect2)

    if rect.width == 0 or rect.height == 0:
        return False

    x1, y1 = rect.x - rect1.x, rect.y - rect1.y
    x2, y2 = rect.x - rect2.x, rect.y - rect2.y

    for x in xrange(rect.width):
        for y in xrange(rect.height):
            if hitmask1[x1+x][y1+y] and hitmask2[x2+x][y2+y]:
                return True
    return False

def getHitmask(image):
    """returns a hitmask using an image's alpha."""
    mask = []
    for x in xrange(image.get_width()):
        mask.append([])
        for y in xrange(image.get_height()):
            mask[x].append(bool(image.get_at((x,y))[3]))
    return mask

if __name__ == '__main__':
    main()