文章先介紹了關(guān)于俄羅斯方塊游戲的幾個(gè)術(shù)語。
- 邊框――由10*20個(gè)空格組成，方塊就落在這里面。
- 盒子――組成方塊的其中小方塊，是組成方塊的基本單元。
- 方塊――從邊框頂?shù)粝碌臇|西，游戲者可以翻轉(zhuǎn)和改變位置。每個(gè)方塊由4個(gè)盒子組成。
- 形狀――不同類型的方塊。這里形狀的名字被叫做T, S, Z ,J, L, I , O。如下圖所示：
模版――用一個(gè)列表存放形狀被翻轉(zhuǎn)后的所有可能樣式。全部存放在變量里，變量名字如S_SHAPE_TEMPLATE or J_SHAPE_TEMPLATE
著陸――當(dāng)一個(gè)方塊到達(dá)邊框的底部或接觸到在其他的盒子話，我們就說這個(gè)方塊著陸了。那樣的話，另一個(gè)方塊就會(huì)開始下落。
下面先把代碼敲一遍，試著了解作者意圖，體會(huì)俄羅斯方塊游戲的制作過程。
import random, time, pygame, sys
from pygame.locals import *
FPS = 25
WINDOWWIDTH = 640
WINDOWHEIGHT = 480
BOXSIZE = 20
BOARDWIDTH = 10
BOARDHEIGHT = 20
BLANK = '.'
MOVESIDEWAYSFREQ = 0.15
MOVEDOWNFREQ = 0.1
XMARGIN = int((WINDOWWIDTH - BOARDWIDTH * BOXSIZE) / 2)
TOPMARGIN = WINDOWHEIGHT - (BOARDHEIGHT * BOXSIZE) - 5
# R G B
WHITE = (255, 255, 255)
GRAY = (185, 185, 185)
BLACK = ( 0, 0, 0)
RED = (155, 0, 0)
LIGHTRED = (175, 20, 20)
GREEN = ( 0, 155, 0)
LIGHTGREEN = ( 20, 175, 20)
BLUE = ( 0, 0, 155)
LIGHTBLUE = ( 20, 20, 175)
YELLOW = (155, 155, 0)
LIGHTYELLOW = (175, 175, 20)
BORDERCOLOR = BLUE
BGCOLOR = BLACK
TEXTCOLOR = WHITE
TEXTSHADOWCOLOR = GRAY
COLORS = ( BLUE, GREEN, RED, YELLOW)
LIGHTCOLORS = (LIGHTBLUE, LIGHTGREEN, LIGHTRED, LIGHTYELLOW)
assert len(COLORS) == len(LIGHTCOLORS) # each color must have light color
TEMPLATEWIDTH = 5
TEMPLATEHEIGHT = 5
S_SHAPE_TEMPLATE = [['.....',
'.....',
'..OO.',
'.OO..',
'.....'],
['.....',
'..O..',
'..OO.',
'...O.',
'.....']]
Z_SHAPE_TEMPLATE = [['.....',
'.....',
'.OO..',
'..OO.',
'.....'],
['.....',
'..O..',
'.OO..',
'.O...',
'.....']]
I_SHAPE_TEMPLATE = [['..O..',
'..O..',
'..O..',
'..O..',
'.....'],
['.....',
'.....',
'OOOO.',
'.....',
'.....']]
O_SHAPE_TEMPLATE = [['.....',
'.....',
'.OO..',
'.OO..',
'.....']]
J_SHAPE_TEMPLATE = [['.....',
'.O...',
'.OOO.',
'.....',
'.....'],
['.....',
'..OO.',
'..O..',
'..O..',
'.....'],
['.....',
'.....',
'.OOO.',
'...O.',
'.....'],
['.....',
'..O..',
'..O..',
'.OO..',
'.....']]
L_SHAPE_TEMPLATE = [['.....',
'...O.',
'.OOO.',
'.....',
'.....'],
['.....',
'..O..',
'..O..',
'..OO.',
'.....'],
['.....',
'.....',
'.OOO.',
'.O...',
'.....'],
['.....',
'.OO..',
'..O..',
'..O..',
'.....']]
T_SHAPE_TEMPLATE = [['.....',
'..O..',
'.OOO.',
'.....',
'.....'],
['.....',
'..O..',
'..OO.',
'..O..',
'.....'],
['.....',
'.....',
'.OOO.',
'..O..',
'.....'],
['.....',
'..O..',
'.OO..',
'..O..',
'.....']]
PIECES = {'S': S_SHAPE_TEMPLATE,
'Z': Z_SHAPE_TEMPLATE,
'J': J_SHAPE_TEMPLATE,
'L': L_SHAPE_TEMPLATE,
'I': I_SHAPE_TEMPLATE,
'O': O_SHAPE_TEMPLATE,
'T': T_SHAPE_TEMPLATE}
def main():
global FPSCLOCK, DISPLAYSURF, BASICFONT, BIGFONT
pygame.init()
FPSCLOCK = pygame.time.Clock()
DISPLAYSURF = pygame.display.set_mode((WINDOWWIDTH, WINDOWHEIGHT))
BASICFONT = pygame.font.Font('freesansbold.ttf', 18)
BIGFONT = pygame.font.Font('freesansbold.ttf', 100)
pygame.display.set_caption('Tetromino')
showTextScreen('Tetromino')
while True: # game loop
if random.randint(0, 1) == 0:
pygame.mixer.music.load('tetrisb.mid')
else:
pygame.mixer.music.load('tetrisc.mid')
pygame.mixer.music.play(-1, 0.0)
runGame()
pygame.mixer.music.stop()
showTextScreen('Game Over')
def runGame():
# setup variables for the start of the game
board = getBlankBoard()
lastMoveDownTime = time.time()
lastMoveSidewaysTime = time.time()
lastFallTime = time.time()
movingDown = False # note: there is no movingUp variable
movingLeft = False
movingRight = False
score = 0
level, fallFreq = calculateLevelAndFallFreq(score)
fallingPiece = getNewPiece()
nextPiece = getNewPiece()
while True: # game loop
if fallingPiece == None:
# No falling piece in play, so start a new piece at the top
fallingPiece = nextPiece
nextPiece = getNewPiece()
lastFallTime = time.time() # reset lastFallTime
if not isValidPosition(board, fallingPiece):
return # can't fit a new piece on the board, so game over
checkForQuit()
for event in pygame.event.get(): # event handling loop
if event.type == KEYUP:
if (event.key == K_p):
# Pausing the game
DISPLAYSURF.fill(BGCOLOR)
pygame.mixer.music.stop()
showTextScreen('Paused') # pause until a key press
pygame.mixer.music.play(-1, 0.0)
lastFallTime = time.time()
lastMoveDownTime = time.time()
lastMoveSidewaysTime = time.time()
elif (event.key == K_LEFT or event.key == K_a):
movingLeft = False
elif (event.key == K_RIGHT or event.key == K_d):
movingRight = False
elif (event.key == K_DOWN or event.key == K_s):
movingDown = False
elif event.type == KEYDOWN:
# moving the piece sideways
if (event.key == K_LEFT or event.key == K_a) and isValidPosition(board, fallingPiece, adjX=-1):
fallingPiece['x'] -= 1
movingLeft = True
movingRight = False
lastMoveSidewaysTime = time.time()
elif (event.key == K_RIGHT or event.key == K_d) and isValidPosition(board, fallingPiece, adjX=1):
fallingPiece['x'] += 1
movingRight = True
movingLeft = False
lastMoveSidewaysTime = time.time()
# rotating the piece (if there is room to rotate)
elif (event.key == K_UP or event.key == K_w):
fallingPiece['rotation'] = (fallingPiece['rotation'] + 1) % len(PIECES[fallingPiece['shape']])
if not isValidPosition(board, fallingPiece):
fallingPiece['rotation'] = (fallingPiece['rotation'] - 1) % len(PIECES[fallingPiece['shape']])
elif (event.key == K_q): # rotate the other direction
fallingPiece['rotation'] = (fallingPiece['rotation'] - 1) % len(PIECES[fallingPiece['shape']])
if not isValidPosition(board, fallingPiece):
fallingPiece['rotation'] = (fallingPiece['rotation'] + 1) % len(PIECES[fallingPiece['shape']])
# making the piece fall faster with the down key
elif (event.key == K_DOWN or event.key == K_s):
movingDown = True
if isValidPosition(board, fallingPiece, adjY=1):
fallingPiece['y'] += 1
lastMoveDownTime = time.time()
# move the current piece all the way down
elif event.key == K_SPACE:
movingDown = False
movingLeft = False
movingRight = False
for i in range(1, BOARDHEIGHT):
if not isValidPosition(board, fallingPiece, adjY=i):
break
fallingPiece['y'] += i - 1
# handle moving the piece because of user input
if (movingLeft or movingRight) and time.time() - lastMoveSidewaysTime > MOVESIDEWAYSFREQ:
if movingLeft and isValidPosition(board, fallingPiece, adjX=-1):
fallingPiece['x'] -= 1
elif movingRight and isValidPosition(board, fallingPiece, adjX=1):
fallingPiece['x'] += 1
lastMoveSidewaysTime = time.time()
if movingDown and time.time() - lastMoveDownTime > MOVEDOWNFREQ and isValidPosition(board, fallingPiece, adjY=1):
fallingPiece['y'] += 1
lastMoveDownTime = time.time()
# let the piece fall if it is time to fall
if time.time() - lastFallTime > fallFreq:
# see if the piece has landed
if not isValidPosition(board, fallingPiece, adjY=1):
# falling piece has landed, set it on the board
addToBoard(board, fallingPiece)
score += removeCompleteLines(board)
level, fallFreq = calculateLevelAndFallFreq(score)
fallingPiece = None
else:
# piece did not land, just move the piece down
fallingPiece['y'] += 1
lastFallTime = time.time()
# drawing everything on the screen
DISPLAYSURF.fill(BGCOLOR)
drawBoard(board)
drawStatus(score, level)
drawNextPiece(nextPiece)
if fallingPiece != None:
drawPiece(fallingPiece)
pygame.display.update()
FPSCLOCK.tick(FPS)
def makeTextObjs(text, font, color):
surf = font.render(text, True, color)
return surf, surf.get_rect()
def terminate():
pygame.quit()
sys.exit()
def checkForKeyPress():
# Go through event queue looking for a KEYUP event.
# Grab KEYDOWN events to remove them from the event queue.
checkForQuit()
for event in pygame.event.get([KEYDOWN, KEYUP]):
if event.type == KEYDOWN:
continue
return event.key
return None
def showTextScreen(text):
# This function displays large text in the
# center of the screen until a key is pressed.
# Draw the text drop shadow
titleSurf, titleRect = makeTextObjs(text, BIGFONT, TEXTSHADOWCOLOR)
titleRect.center = (int(WINDOWWIDTH / 2), int(WINDOWHEIGHT / 2))
DISPLAYSURF.blit(titleSurf, titleRect)
# Draw the text
titleSurf, titleRect = makeTextObjs(text, BIGFONT, TEXTCOLOR)
titleRect.center = (int(WINDOWWIDTH / 2) - 3, int(WINDOWHEIGHT / 2) - 3)
DISPLAYSURF.blit(titleSurf, titleRect)
# Draw the additional "Press a key to play." text.
pressKeySurf, pressKeyRect = makeTextObjs('Press a key to play.', BASICFONT, TEXTCOLOR)
pressKeyRect.center = (int(WINDOWWIDTH / 2), int(WINDOWHEIGHT / 2) + 100)
DISPLAYSURF.blit(pressKeySurf, pressKeyRect)
while checkForKeyPress() == None:
pygame.display.update()
FPSCLOCK.tick()
def checkForQuit():
for event in pygame.event.get(QUIT): # get all the QUIT events
terminate() # terminate if any QUIT events are present
for event in pygame.event.get(KEYUP): # get all the KEYUP events
if event.key == K_ESCAPE:
terminate() # terminate if the KEYUP event was for the Esc key
pygame.event.post(event) # put the other KEYUP event objects back
def calculateLevelAndFallFreq(score):
# Based on the score, return the level the player is on and
# how many seconds pass until a falling piece falls one space.
level = int(score / 10) + 1
fallFreq = 0.27 - (level * 0.02)
return level, fallFreq
def getNewPiece():
# return a random new piece in a random rotation and color
shape = random.choice(list(PIECES.keys()))
newPiece = {'shape': shape,
'rotation': random.randint(0, len(PIECES[shape]) - 1),
'x': int(BOARDWIDTH / 2) - int(TEMPLATEWIDTH / 2),
'y': -2, # start it above the board (i.e. less than 0)
'color': random.randint(0, len(COLORS)-1)}
return newPiece
def addToBoard(board, piece):
# fill in the board based on piece's location, shape, and rotation
for x in range(TEMPLATEWIDTH):
for y in range(TEMPLATEHEIGHT):
if PIECES[piece['shape']][piece['rotation']][y][x] != BLANK:
board[x + piece['x']][y + piece['y']] = piece['color']
def getBlankBoard():
# create and return a new blank board data structure
board = []
for i in range(BOARDWIDTH):
board.append([BLANK] * BOARDHEIGHT)
return board
def isOnBoard(x, y):
return x >= 0 and x < BOARDWIDTH and y < BOARDHEIGHT
def isValidPosition(board, piece, adjX=0, adjY=0):
# Return True if the piece is within the board and not colliding
for x in range(TEMPLATEWIDTH):
for y in range(TEMPLATEHEIGHT):
isAboveBoard = y + piece['y'] + adjY < 0
if isAboveBoard or PIECES[piece['shape']][piece['rotation']][y][x] == BLANK:
continue
if not isOnBoard(x + piece['x'] + adjX, y + piece['y'] + adjY):
return False
if board[x + piece['x'] + adjX][y + piece['y'] + adjY] != BLANK:
return False
return True
def isCompleteLine(board, y):
# Return True if the line filled with boxes with no gaps.
for x in range(BOARDWIDTH):
if board[x][y] == BLANK:
return False
return True
def removeCompleteLines(board):
# Remove any completed lines on the board, move everything above them down, and return the number of complete lines.
numLinesRemoved = 0
y = BOARDHEIGHT - 1 # start y at the bottom of the board
while y >= 0:
if isCompleteLine(board, y):
# Remove the line and pull boxes down by one line.
for pullDownY in range(y, 0, -1):
for x in range(BOARDWIDTH):
board[x][pullDownY] = board[x][pullDownY-1]
# Set very top line to blank.
for x in range(BOARDWIDTH):
board[x][0] = BLANK
numLinesRemoved += 1
# Note on the next iteration of the loop, y is the same.
# This is so that if the line that was pulled down is also
# complete, it will be removed.
else:
y -= 1 # move on to check next row up
return numLinesRemoved
def convertToPixelCoords(boxx, boxy):
# Convert the given xy coordinates of the board to xy
# coordinates of the location on the screen.
return (XMARGIN + (boxx * BOXSIZE)), (TOPMARGIN + (boxy * BOXSIZE))
def drawBox(boxx, boxy, color, pixelx=None, pixely=None):
# draw a single box (each tetromino piece has four boxes)
# at xy coordinates on the board. Or, if pixelx & pixely
# are specified, draw to the pixel coordinates stored in
# pixelx & pixely (this is used for the "Next" piece).
if color == BLANK:
return
if pixelx == None and pixely == None:
pixelx, pixely = convertToPixelCoords(boxx, boxy)
pygame.draw.rect(DISPLAYSURF, COLORS[color], (pixelx + 1, pixely + 1, BOXSIZE - 1, BOXSIZE - 1))
pygame.draw.rect(DISPLAYSURF, LIGHTCOLORS[color], (pixelx + 1, pixely + 1, BOXSIZE - 4, BOXSIZE - 4))
def drawBoard(board):
# draw the border around the board
pygame.draw.rect(DISPLAYSURF, BORDERCOLOR, (XMARGIN - 3, TOPMARGIN - 7, (BOARDWIDTH * BOXSIZE) + 8, (BOARDHEIGHT * BOXSIZE) + 8), 5)
# fill the background of the board
pygame.draw.rect(DISPLAYSURF, BGCOLOR, (XMARGIN, TOPMARGIN, BOXSIZE * BOARDWIDTH, BOXSIZE * BOARDHEIGHT))
# draw the individual boxes on the board
for x in range(BOARDWIDTH):
for y in range(BOARDHEIGHT):
drawBox(x, y, board[x][y])
def drawStatus(score, level):
# draw the score text
scoreSurf = BASICFONT.render('Score: %s' % score, True, TEXTCOLOR)
scoreRect = scoreSurf.get_rect()
scoreRect.topleft = (WINDOWWIDTH - 150, 20)
DISPLAYSURF.blit(scoreSurf, scoreRect)
# draw the level text
levelSurf = BASICFONT.render('Level: %s' % level, True, TEXTCOLOR)
levelRect = levelSurf.get_rect()
levelRect.topleft = (WINDOWWIDTH - 150, 50)
DISPLAYSURF.blit(levelSurf, levelRect)
def drawPiece(piece, pixelx=None, pixely=None):
shapeToDraw = PIECES[piece['shape']][piece['rotation']]
if pixelx == None and pixely == None:
# if pixelx & pixely hasn't been specified, use the location stored in the piece data structure
pixelx, pixely = convertToPixelCoords(piece['x'], piece['y'])
# draw each of the boxes that make up the piece
for x in range(TEMPLATEWIDTH):
for y in range(TEMPLATEHEIGHT):
if shapeToDraw[y][x] != BLANK:
drawBox(None, None, piece['color'], pixelx + (x * BOXSIZE), pixely + (y * BOXSIZE))
def drawNextPiece(piece):
# draw the "next" text
nextSurf = BASICFONT.render('Next:', True, TEXTCOLOR)
nextRect = nextSurf.get_rect()
nextRect.topleft = (WINDOWWIDTH - 120, 80)
DISPLAYSURF.blit(nextSurf, nextRect)
# draw the "next" piece
drawPiece(piece, pixelx=WINDOWWIDTH-120, pixely=100)
if __name__ == '__main__':
main()
代碼一開始仍是一些變量的初始化，我們這里還加載了time模塊，后面會(huì)用到。BOXSIZE， BOARDWIDTH, BOARDHEIGHT與前面貪吃蛇相關(guān)初始化類似，使其與屏幕像素點(diǎn)聯(lián)系起來。
MOVESIDEWAYSFREQ = 0.15
MOVEDOWNFREQ = 0.1
這兩個(gè)變量的作用是這樣的，每當(dāng)游戲者按下左鍵或右鍵，下降的方塊相應(yīng)的向左或右移一個(gè)格子。然而游戲者也可以一直按下方向左鍵或右鍵讓方塊保持移動(dòng)。MOVESIDEWAYSFREQ這個(gè)固定值表示如果一直按下方向左鍵或右鍵那么每0.15秒方塊才會(huì)繼續(xù)移動(dòng)。
MOVEDOWNFREQ 這個(gè)固定值與上面的是一樣的除了它是告訴當(dāng)游戲者一直按下方向下鍵時(shí)方塊下落的頻率。
XMARGIN = int((WINDOWWIDTH - BOARDWIDTH * BOXSIZE) / 2)
TOPMARGIN = WINDOWHEIGHT - (BOARDHEIGHT * BOXSIZE) - 5
這兩句的意思就看下面這個(gè)圖就明白了。
然后是一些顏色值的定義。其中要注意的是COLORS和LIGHTCOLORS，COLORS是組成方塊的小方塊的顏色，而LIGHTCOLORS是圍繞在小方塊周圍的顏色，為了強(qiáng)調(diào)出輪廓而設(shè)計(jì)的。
接著是定義方塊了。游戲必須知道每個(gè)類型的方塊有多少種形狀，在這里我們用在列表中嵌入含有字符串的列表來構(gòu)成這個(gè)模版，一個(gè)方塊類型的模版含有了這個(gè)方塊可能變換的所有形狀。比如I的模版如下：
I_SHAPE_TEMPLATE = [['..O..',
'..O..',
'..O..',
'..O..',
'.....'],
['.....',
'.....',
'OOOO.',
'.....',
'.....']]
TEMPLATEWIDTH = 5和TEMPLATEHEIGHT = 5則表示組成形狀的行和列，如下圖所示：
在看這段定義。
PIECES = {'S': S_SHAPE_TEMPLATE,
'Z': Z_SHAPE_TEMPLATE,
'J': J_SHAPE_TEMPLATE,
'L': L_SHAPE_TEMPLATE,
'I': I_SHAPE_TEMPLATE,
'O': O_SHAPE_TEMPLATE,
'T': T_SHAPE_TEMPLATE}
PIECES這個(gè)變量是一個(gè)字典，里面儲(chǔ)存了所有的不同模版。因?yàn)槊總€(gè)又有一個(gè)類型的方塊的所有變換形狀。那就意味著PIECES變量包含了每個(gè)類型的方塊和所有的的變換形狀。這就是存放我們游戲中用到的形狀的數(shù)據(jù)結(jié)構(gòu)。（又加強(qiáng)了對(duì)字典的理解）
主函數(shù)main()
主函數(shù)的前部分主要是創(chuàng)建一些全局變量和在游戲開始之前顯示一個(gè)開始畫面。
while True: # game loop
if random.randint(0, 1) == 0:
pygame.mixer.music.load('tetrisb.mid')
else:
pygame.mixer.music.load('tetrisc.mid')
pygame.mixer.music.play(-1, 0.0)
runGame()
pygame.mixer.music.stop()
showTextScreen('Game Over')
上面這段代碼中runGame()是程序的核心部分。循環(huán)中首先簡(jiǎn)單的隨機(jī)決定采用哪個(gè)背景音樂。然后調(diào)用runGame()，當(dāng)游戲失敗，runGame()就會(huì)返回到main()函數(shù)，這時(shí)會(huì)停止背景音樂和顯示游戲失敗的畫面。
當(dāng)游戲者按下一個(gè)鍵，showTextScreen()顯示游戲失敗的函數(shù)就會(huì)返回。游戲循環(huán)會(huì)再次開始然后繼續(xù)下一次游戲。
runGame()
def runGame():
# setup variables for the start of the game
board = getBlankBoard()
lastMoveDownTime = time.time()
lastMoveSidewaysTime = time.time()
lastFallTime = time.time()
movingDown = False # note: there is no movingUp variable
movingLeft = False
movingRight = False
score = 0
level, fallFreq = calculateLevelAndFallFreq(score)
fallingPiece = getNewPiece()
nextPiece = getNewPiece()
在游戲開始和方塊掉落之前，我們需要初始化一些跟游戲開始相關(guān)的變量。fallingPiece變量被賦值成當(dāng)前掉落的變量，nextPiece變量被賦值成游戲者可以在屏幕NEXT區(qū)域看見的下一個(gè)方塊。
while True: # game loop
if fallingPiece == None:
# No falling piece in play, so start a new piece at the top
fallingPiece = nextPiece
nextPiece = getNewPiece()
lastFallTime = time.time() # reset lastFallTime
if not isValidPosition(board, fallingPiece):
return # can't fit a new piece on the board, so game over
checkForQuit()
這部分包含了當(dāng)方塊往底部掉落時(shí)的的所有代碼。fallingPiece變量在方塊著陸后被設(shè)置成None。這意味著nextPiece變量中的下一個(gè)方塊應(yīng)該被賦值給fallingPiece變量，然后一個(gè)隨機(jī)的方塊又會(huì)被賦值給nextPiece變量。lastFallTime變量也被賦值成當(dāng)前時(shí)間，這樣我們就可以通過fallFreq變量控制方塊下落的頻率。
來自getNewPiece函數(shù)的方塊只有一部分被放置在方框區(qū)域中。但是如果這是一個(gè)非法的位置，比如此時(shí)游戲方框已經(jīng)被填滿（isVaildPostion()函數(shù)返回False），那么我們就知道方框已經(jīng)滿了，游戲者輸?shù)袅擞螒颉．?dāng)這些發(fā)生時(shí)，runGame()函數(shù)就會(huì)返回。
事件處理循環(huán)
事件循環(huán)主要處理當(dāng)翻轉(zhuǎn)方塊，移動(dòng)方塊時(shí)或者暫停游戲時(shí)的一些事情。
暫停游戲
if (event.key == K_p):
# Pausing the game
DISPLAYSURF.fill(BGCOLOR)
pygame.mixer.music.stop()
showTextScreen('Paused') # pause until a key press
pygame.mixer.music.play(-1, 0.0)
lastFallTime = time.time()
lastMoveDownTime = time.time()
lastMoveSidewaysTime = time.time()
如果游戲者按下P鍵，游戲就會(huì)暫停。我們應(yīng)該隱藏掉游戲界面以防止游戲者作弊（否則游戲者會(huì)看著畫面思考怎么處理方塊），用DISPLAYSURF.fill(BGCOLOR)就可以實(shí)現(xiàn)這個(gè)效果。注意的是我們還要保存一些時(shí)間變量值。
elif (event.key == K_LEFT or event.key == K_a):
movingLeft = False
elif (event.key == K_RIGHT or event.key == K_d):
movingRight = False
elif (event.key == K_DOWN or event.key == K_s):
movingDown = False
停止按下方向鍵或ASD鍵會(huì)把moveLeft,moveRight,movingDown變量設(shè)置為False.,表明游戲者不再想要在此方向上移動(dòng)方塊。后面的代碼會(huì)基于moving變量處理一些事情。注意的上方向鍵和W鍵是用來翻轉(zhuǎn)方塊的而不是移動(dòng)方塊。這就是為什么沒有movingUp變量.
elif event.type == KEYDOWN:
# moving the piece sideways
if (event.key == K_LEFT or event.key == K_a) and isValidPosition(board, fallingPiece, adjX=-1):
fallingPiece['x'] -= 1
movingLeft = True
movingRight = False
lastMoveSidewaysTime = time.time()
當(dāng)左方向鍵按下（而且往左移動(dòng)是有效的，通過調(diào)用isVaildPosition()函數(shù)知道的），那么我們應(yīng)該改變一個(gè)方塊的位置使其向左移動(dòng)一個(gè)通過讓rallingPiece['x']減1.isVaildPosition()函數(shù)有個(gè)參數(shù)選項(xiàng)是adjX和adjY.平常，isVaildPostion()函數(shù)檢查方塊的位置通過函數(shù)的第二個(gè)參數(shù)的傳遞。然而，有時(shí)我們不想檢查方塊當(dāng)前的位置，而是偏離當(dāng)前方向幾個(gè)格子的位置。
比如adjX=-1，則表示向左移動(dòng)一個(gè)格子后方塊的位置，為+1則表示向右移動(dòng)一個(gè)格子后的位置。adjY同理如此。
movingLeft變量會(huì)被設(shè)置為True，確保方塊不會(huì)向右移動(dòng)，此時(shí)movingRight變量設(shè)置為False。同時(shí)需要更新lastMoveSidewaysTime的值。
這個(gè)lastMoveSidewaysTime變量設(shè)置的原因是這樣。因?yàn)橛螒蛘哂锌赡芤恢卑粗较蜴I讓其方塊移動(dòng)。如果moveLeft被設(shè)置為True，程序就會(huì)知道方向左鍵已經(jīng)被按下。如果在lastMoveSidewaysTime變量?jī)?chǔ)存的時(shí)間基礎(chǔ)上，0.15秒（儲(chǔ)存在MOVESIDEAYSFREQ變量中）過去后，那么此時(shí)程序就會(huì)將方塊再次向左移動(dòng)一個(gè)格子。
elif (event.key == K_UP or event.key == K_w):
fallingPiece['rotation'] = (fallingPiece['rotation'] + 1) % len(PIECES[fallingPiece['shape']])
if not isValidPosition(board, fallingPiece):
fallingPiece['rotation'] = (fallingPiece['rotation'] - 1) % len(PIECES[fallingPiece['shape']])
如果方向鍵上或W鍵被按下，那么就會(huì)翻轉(zhuǎn)方塊。上面的代碼做的就是將儲(chǔ)存在fallingPiece字典中的‘rotation'鍵的鍵值加1.然而，當(dāng)增加的'rotation'鍵值大于所有當(dāng)前類型方塊的形狀的數(shù)目的話（此變量?jī)?chǔ)存在len(SHAPES[fallingPiece['shape']])變量中），那么它翻轉(zhuǎn)到最初的形狀。
?
if not isValidPosition(board, fallingPiece):
fallingPiece['rotation'] = (fallingPiece['rotation'] - 1) % len(PIECES[fallingPiece['shape']])
如果翻轉(zhuǎn)后的形狀無效因?yàn)槠渲械囊恍┬》綁K已經(jīng)超過邊框的范圍，那么我們就要把它變回原來的形狀通過將fallingPiece['rotation')減去1.
elif (event.key == K_q): # rotate the other direction
fallingPiece['rotation'] = (fallingPiece['rotation'] - 1) % len(PIECES[fallingPiece['shape']])
if not isValidPosition(board, fallingPiece):
fallingPiece['rotation'] = (fallingPiece['rotation'] + 1) % len(PIECES[fallingPiece['shape']])
這段代碼與上面之前的那段代碼是一個(gè)意思，不同的是這段代碼是當(dāng)游戲者按下Q鍵時(shí)翻轉(zhuǎn)方塊朝相反的方向。這里我們減去1而不是加1.
elif (event.key == K_DOWN or event.key == K_s):
movingDown = True
if isValidPosition(board, fallingPiece, adjY=1):
fallingPiece['y'] += 1
lastMoveDownTime = time.time()
如果下鍵被按下，游戲者此時(shí)希望方塊下降的比平常快。fallingPiece['y'] += 1使方塊下落一個(gè)格子（前提是這是一個(gè)有效的下落）moveDown被設(shè)置為True，lastMoceDownTime變量也被設(shè)置為當(dāng)前時(shí)間。這個(gè)變量以后將被檢查當(dāng)方向下鍵一直按下時(shí)從而保證方塊以一個(gè)比平?？斓乃俾氏陆怠?
elif event.key == K_SPACE:
movingDown = False
movingLeft = False
movingRight = False
for i in range(1, BOARDHEIGHT):
if not isValidPosition(board, fallingPiece, adjY=i):
break
fallingPiece['y'] += i - 1
當(dāng)游戲者按下空格鍵，方塊將會(huì)迅速的下落至著陸。程序首先需要找出到它著陸需要下降個(gè)多少個(gè)格子。其中有關(guān)moving的三個(gè)變量都要被設(shè)置為False（保證程序后面部分的代碼知道游戲者已經(jīng)停止了按下所有的方向鍵）。
if (movingLeft or movingRight) and time.time() - lastMoveSidewaysTime > MOVESIDEWAYSFREQ:
if movingLeft and isValidPosition(board, fallingPiece, adjX=-1):
fallingPiece['x'] -= 1
elif movingRight and isValidPosition(board, fallingPiece, adjX=1):
fallingPiece['x'] += 1
lastMoveSidewaysTime = time.time()
這段代碼是處理一直按下某個(gè)方向鍵時(shí)的情況。
如果用戶按住鍵超過0.15秒。那么表達(dá)式(movingLeft or movingRight) and time.time() - lastMoveSidewaysTime > MOVESIDEWAYSFREQ:返回True。這樣的話我們就可以移動(dòng)方塊向左或向右移動(dòng)一個(gè)格子。
這個(gè)做法是很用的，因?yàn)槿绻脩糁貜?fù)的按下方向鍵讓方塊移動(dòng)多個(gè)格子是很煩人的。好的做法是，用戶可以按住方向鍵讓方塊保持移動(dòng)直到松開鍵為止。最后別忘了更新lastMoveSideWaysTime變量。
if movingDown and time.time() - lastMoveDownTime > MOVEDOWNFREQ and isValidPosition(board, fallingPiece, adjY=1):
fallingPiece['y'] += 1
lastMoveDownTime = time.time()
這段代碼的意思跟上面的代碼差不多。
if time.time() - lastFallTime > fallFreq:
# see if the piece has landed
if not isValidPosition(board, fallingPiece, adjY=1):
# falling piece has landed, set it on the board
addToBoard(board, fallingPiece)
score += removeCompleteLines(board)
level, fallFreq = calculateLevelAndFallFreq(score)
fallingPiece = None
else:
# piece did not land, just move the piece down
fallingPiece['y'] += 1
lastFallTime = time.time()
方塊自然下落的速率由lastFallTime變量決定。如果自從上個(gè)方塊掉落了一個(gè)格子后過去了足夠的時(shí)間，那么上面代碼就會(huì)再讓方塊移動(dòng)一個(gè)格子。
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