python实现Flappy Bird源码

Flappy Bird是前段时间（好像一年or两年前....）特别火的有一个小游戏，相信大家都玩过。

Flappy Bird操作简单，通过点击手机屏幕使Bird上升，穿过柱状障碍物之后得分，碰到则游戏结束。由于障碍物高低不等，控制Bird上升和下降需要反应快并且灵活，要得到较高的分数并不容易。作为一个游戏渣，我最高纪录是8分......

我记得当时还想，是谁发明了这个小游戏，逼死强迫症，记得当时本科时好多人在玩....

无意间在GitHub上看到了python实现的代码，所以拿来学习了一番。代码思路比较简洁。

因为第一次接触pygame，所以代码注释写的比较详细，也算是一次新体验。

玩法：空格键进入游戏，↑控制小鸟飞行

注意：需要安装pygame模块

代码：

# -*- coding: utf8 -*-

from itertools import cycle
import random
import sys

import pygame #将pygame库导入到python程序中
from pygame.locals import * #需要引入pygame中的所有常量。

FPS = 30
SCREENWIDTH = 288 #屏幕宽度
SCREENHEIGHT = 512 #屏幕高度
# amount by which base can maximum shift to left
PIPEGAPSIZE = 100 # gap between upper and lower part of pipe 管道上下之间的间隙
BASEY  = SCREENHEIGHT * 0.79 #base那个条条所在的高度 注意以左上角为坐标起始点 所以这个高度是往下为正
# image, sound and hitmask dicts
IMAGES, SOUNDS, HITMASKS = {}, {}, {} #图像，声音，撞击的文件

# list of all possible players (tuple of 3 positions of flap) #三种小鸟造型
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 两种背景，一种白天，一种黑夜
BACKGROUNDS_LIST = (
 'assets/sprites/background-day.png',
 'assets/sprites/background-night.png',
)

# list of pipes 管道的两种颜色，一种绿色，一种红色
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() #经过初始化以后我们就可以尽情地使用pygame了。

 #使用Pygame时钟之前，必须先创建Clock对象的一个实例，
 FPSCLOCK = pygame.time.Clock()#控制每个循环多长时间运行一次。这就像一个定时器在控制时间进程，指出“现在开始下一个循环”！现在开始下一个循环！……

 SCREEN = pygame.display.set_mode((SCREENWIDTH, SCREENHEIGHT))#通常来说我们需要先创建一个窗口，方便我们与程序的交互。
 pygame.display.set_caption('Flappy Bird')#设置窗口标题

 # numbers sprites for score display #加载并转换图像
 #在pygame中可以使用pygame.image.load（）函数来加载位图 （支持jpg,png,gif,bmp,pcx,tif,tga等多种图片格式）。
 #convert_alpha()方法会使用透明的方法绘制前景对象。
 # 因此在加载一个有alpha通道的素材时（比如PNG TGA），需要使用convert_alpha()方法，当然普通的图片也是可以使用这个方法的，用了也不会有什么副作用。
 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 游戏结束显示的图像
 IMAGES['gameover'] = pygame.image.load('assets/sprites/gameover.png').convert_alpha()
 # message sprite for welcome screen 欢迎界面显示的图像
 IMAGES['message'] = pygame.image.load('assets/sprites/message.png').convert_alpha()
 # base (ground) sprite 始终显示的base图像
 IMAGES['base'] = pygame.image.load('assets/sprites/base.png').convert_alpha()

 # sounds
 # WAV版 OGG版是指游戏的音频格式
 # WAV版是属于游戏原版
 # OGG是大大们通过转换器把音频格式的WAV改成OGG，这样游戏的配置提高要求使游戏本身的体积而缩小节省了空间。
 #可以看一下同一个音频 ogg版的是比wav版的文件小很多
 if 'win' in sys.platform: #判断当前系统平台 来设置声音文件后缀
  soundExt = '.wav'
 else:
  soundExt = '.ogg'

 # 音效:pygame.mixer
 # sound = pygame.mixer.Sound('/home/liumin/love.wav')使用指定文件名载入一个音频文件，并创建一个Sound对象。 音频文件可以是wav,ogg等格式。
 # 音频文件的内容会被全部载入到内存中。
 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)

 while True:
  # select random background sprites 加载随机背景 （白天或者黑夜）
  randBg = random.randint(0, len(BACKGROUNDS_LIST) - 1)#随机选择0或者1
  IMAGES['background'] = pygame.image.load(BACKGROUNDS_LIST[randBg]).convert()#加载随机背景

  # select random player sprites 加载随机角色 （红色、蓝色、黄色小鸟）
  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 加载随机管道样式
  pipeindex = random.randint(0, len(PIPES_LIST) - 1)
  IMAGES['pipe'] = (
   pygame.transform.rotate(
    pygame.image.load(PIPES_LIST[pipeindex]).convert_alpha(), 180),#旋转180度
   pygame.image.load(PIPES_LIST[pipeindex]).convert_alpha(),
  )#一个上面的管道 一个下面的管道

  # hismask for pipes #得到管道的边界mask
  HITMASKS['pipe'] = (
   getHitmask(IMAGES['pipe'][0]),
   getHitmask(IMAGES['pipe'][1]),
  )

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

  movementInfo = showWelcomeAnimation()#返回'playery'（player所在位置）,'basex'（base图像所在位置） 'playerIndexGen'（飞行姿势index）
  crashInfo = mainGame(movementInfo)
  showGameOverScreen(crashInfo)

def showWelcomeAnimation():
 """Shows welcome screen animation of flappy bird"""
 # index of player to blit on screen
 playerIndex = 0
 playerIndexGen = cycle([0, 1, 2, 1])
 # iterator used to change playerIndex after every 5th iteration
 loopIter = 0

 #player所在位置
 playerx = int(SCREENWIDTH * 0.2)
 playery = int((SCREENHEIGHT - IMAGES['player'][0].get_height()) / 2)
 #欢迎图像所在位置
 messagex = int((SCREENWIDTH - IMAGES['message'].get_width()) / 2)
 messagey = int(SCREENHEIGHT * 0.12)

 basex = 0
 # amount by which base can maximum shift to left 可以最大限度地向左移动的距离
 baseShift = IMAGES['base'].get_width() - IMAGES['background'].get_width()

 # player shm for up-down motion on welcome screen 角色在欢迎屏幕上进行上下移动
 playerShmVals = {'val': 0, 'dir': 1}

 while True:
  for event in pygame.event.get():#使用pygame.event.get()来处理所有的事件,
   if event.type == QUIT or (event.type == KEYDOWN and event.key == K_ESCAPE):#如果 quit 或者 按键之后又按下esc，就结束游戏
    pygame.quit()
    sys.exit()
   if event.type == KEYDOWN and (event.key == K_SPACE or event.key == K_UP):#如果按键之后点击或者按下↑
    # make first flap sound and return values for mainGame
    SOUNDS['wing'].play()#播放飞的特效声音
    return {#返回初始位置 进入maingame
     'playery': playery + playerShmVals['val'],
     'basex': basex,
     'playerIndexGen': playerIndexGen,
    }

  # adjust playery, playerIndex, basex
  if (loopIter + 1) % 5 == 0:
   playerIndex = next(playerIndexGen)#获得匹配元素集合中每个元素紧邻的同胞元素 调整飞行姿势图片
  loopIter = (loopIter + 1) % 30
  basex = -((-basex + 4) % baseShift)
  playerShm(playerShmVals)

  # draw sprites
  #screen.blit(space, (0,0))可以绘制位图 第一个参数是加载完成的位图，第二个参数是绘制的起始坐标。
  SCREEN.blit(IMAGES['background'], (0,0))
  SCREEN.blit(IMAGES['player'][playerIndex],
     (playerx, playery + playerShmVals['val']))
  SCREEN.blit(IMAGES['message'], (messagex, messagey))
  SCREEN.blit(IMAGES['base'], (basex, BASEY))

  pygame.display.update()#更新整个窗口
  FPSCLOCK.tick(FPS)#循环应该多长时间运行一次

def mainGame(movementInfo):
 score = playerIndex = loopIter = 0#初始得分以及初始player的姿态以及迭代次数都为0
 playerIndexGen = movementInfo['playerIndexGen']#得到飞行姿势
 playerx, playery = int(SCREENWIDTH * 0.2), movementInfo['playery']#player所在位置

 basex = movementInfo['basex']#base图像所在位置
 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 velocity, downward accleration, accleration on flap 角色速度，最大速度，向下加速度，襟翼加速度
 playerVelY = -9 # player's velocity along Y, default same as 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:
  for event in pygame.event.get():
   if event.type == QUIT or (event.type == KEYDOWN and event.key == K_ESCAPE):
    pygame.quit()
    sys.exit()
   if event.type == KEYDOWN and (event.key == K_SPACE or event.key == K_UP):
    if playery > -2 * IMAGES['player'][0].get_height():#如果点击
     playerVelY = playerFlapAcc#上升
     playerFlapped = True
     SOUNDS['wing'].play()#并播放飞行音效

  # check for crash here
  crashTest = checkCrash({'x': playerx, 'y': playery, 'index': playerIndex},
        upperPipes, lowerPipes)
  if crashTest[0]:#如果掉在地上或者撞击到了管道，就返回结束游戏
   return {
    'y': playery,
    'groundCrash': crashTest[1],
    'basex': basex,
    'upperPipes': upperPipes,
    'lowerPipes': lowerPipes,
    'score': score,
    'playerVelY': playerVelY,
    'playerRot': playerRot
   }

  # 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:#当角色达到管道缝隙的中间+4时，score+1，并且在此时播放得分音效
    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 #管道移动
   lPipe['x'] += pipeVelX

  # add new pipe when first pipe is about to touch left of screen
  if 0 < upperPipes[0]['x'] < 5:#当第一个管道移动到屏幕左侧边缘时，生成下一个管道
   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(): #当管道移动到屏幕外侧后，删除它
   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) #显示得分

  # Player rotation has a threshold
  visibleRot = playerRotThr
  if playerRot <= playerRotThr:
   visibleRot = playerRot

  playerSurface = pygame.transform.rotate(IMAGES['player'][playerIndex], visibleRot)#旋转角色
  SCREEN.blit(playerSurface, (playerx, playery))#显示旋转后的角色

  pygame.display.update()#更新窗口
  FPSCLOCK.tick(FPS)#循环应该多长时间运行一次

def showGameOverScreen(crashInfo):
 """crashes the player down ans shows gameover image"""
 score = crashInfo['score']#获取得分
 playerx = SCREENWIDTH * 0.2
 playery = crashInfo['y']
 playerHeight = IMAGES['player'][0].get_height()
 playerVelY = crashInfo['playerVelY']
 playerAccY = 2
 playerRot = crashInfo['playerRot']
 playerVelRot = 7

 basex = crashInfo['basex']

 upperPipes, lowerPipes = crashInfo['upperPipes'], crashInfo['lowerPipes']

 # play hit and die sounds
 SOUNDS['hit'].play()
 if not crashInfo['groundCrash']:#如果没有撞击到地面，就播放die音效就可以了
  SOUNDS['die'].play()

 while True:
  for event in pygame.event.get():
   if event.type == QUIT or (event.type == KEYDOWN and event.key == K_ESCAPE):
    pygame.quit()
    sys.exit()
   if event.type == KEYDOWN and (event.key == K_SPACE or event.key == K_UP):
    if playery + playerHeight >= BASEY - 1:
     return

  # player y shift
  if playery + playerHeight < BASEY - 1:
   playery += min(playerVelY, BASEY - playery - playerHeight)

  # player velocity change
  if playerVelY < 15:
   playerVelY += playerAccY

  # rotate only when it's a pipe crash
  if not crashInfo['groundCrash']:
   if playerRot > -90:
    playerRot -= playerVelRot

  # 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))
  showScore(score)

  playerSurface = pygame.transform.rotate(IMAGES['player'][1], playerRot)
  SCREEN.blit(playerSurface, (playerx,playery))

  FPSCLOCK.tick(FPS)
  pygame.display.update()

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():#随机生成随机高度的管道 ？？？？？？？？还需要看细节
 """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

 return [
  {'x': pipeX, 'y': gapY - pipeHeight}, # upper pipe
  {'x': pipeX, 'y': gapY + PIPEGAPSIZE}, # 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))#显示得分
  Xoffset += IMAGES['numbers'][digit].get_width()

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

 # if player crashes into ground 掉在地上
 if player['y'] + player['h'] >= BASEY - 1:
  return [True, True] #返回
 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:#如果撞击到了上管道或者下管道 返回
    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)#角色和管道之间重合的情况

 if rect.width == 0 or rect.height == 0:#没重合就是没撞击到
  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]:#撞击到了
    return True
 return False

def getHitmask(image):
 """returns a hitmask using an image's alpha."""
 #得到撞击mask
 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()

游戏截图：

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