Make Games with Python & Pygame (5)
接着貪吃蛇的下面一章就是俄羅斯方塊，這也是我之前喜歡玩的遊戲之一。它的代碼量也比貪吃蛇多多了，有大約500行。不過整個思路很容易的。python
文章先介紹了關於俄羅斯方塊遊戲的幾個術語。數據結構
- 邊框——由10*20個空格組成，方塊就落在這裏面。
- 盒子——組成方塊的其中小方塊，是組成方塊的基本單元。
- 方塊——從邊框頂掉下的東西，遊戲者能夠翻轉和改變位置。每一個方塊由4個盒子組成。
- 形狀——不一樣類型的方塊。這裏形狀的名字被叫作T, S, Z ,J, L, I , O。以下圖所示：
- 模版——用一個列表存放形狀被翻轉後的全部可能樣式。所有存放在變量裏，變量名字如S_SHAPE_TEMPLATE or J_SHAPE_TEMPLATE
- 着陸——當一個方塊到達邊框的底部或接觸到在其餘的盒子話，咱們就說這個方塊着陸了。那樣的話，另外一個方塊就會開始下落。
下面先把代碼敲一遍，試着瞭解做者意圖，體會俄羅斯方塊遊戲的製做過程。app
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()
代碼一開始還是一些變量的初始化，咱們這裏還加載了time模塊，後面會用到。BOXSIZE， BOARDWIDTH, BOARDHEIGHT與前面貪吃蛇相關初始化相似，使其與屏幕像素點聯繫起來。less
MOVESIDEWAYSFREQ = 0.15
MOVEDOWNFREQ = 0.1
dom
這兩個變量的做用是這樣的，每當遊戲者按下左鍵或右鍵，降低的方塊相應的向左或右移一個格子。然而遊戲者也能夠一直按下方向左鍵或右鍵讓方塊保持移動。MOVESIDEWAYSFREQ這個固定值表示若是一直按下方向左鍵或右鍵那麼每0.15秒方塊纔會繼續移動。ide
MOVEDOWNFREQ 這個固定值與上面的是同樣的除了它是告訴當遊戲者一直按下方向下鍵時方塊下落的頻率。
函數
XMARGIN = int((WINDOWWIDTH - BOARDWIDTH * BOXSIZE) / 2)
TOPMARGIN = WINDOWHEIGHT - (BOARDHEIGHT * BOXSIZE) - 5
oop
這兩句的意思就看下面這個圖就明白了。post
而後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，爲了強調出輪廓而設計的。ui
接着是定義方塊了。遊戲必須知道每一個類型的方塊有多少種形狀，在這裏咱們用在列表中嵌入含有字符串的列表來構成這個模版，一個方塊類型的模版含有了這個方塊可能變換的全部形狀。好比I的模版以下：
I_SHAPE_TEMPLATE = [['..O..',
'..O..',
'..O..',
'..O..',
'.....'],
['.....',
'.....',
'OOOO.',
'.....',
'.....']]
TEMPLATEWIDTH = 5和TEMPLATEHEIGHT = 5則表示組成形狀的行和列，以下圖所示：
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這個變量是一個字典，裏面儲存了全部的不一樣模版。由於每一個又有一個類型的方塊的全部變換形狀。那就意味着PIECES變量包含了每一個類型的方塊和全部的的變換形狀。這就是存放咱們遊戲中用到的形狀的數據結構。（又增強了對字典的理解）
主函數main()
主函數的前部分主要是建立一些全局變量和在遊戲開始以前顯示一個開始畫面。
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。循環中首先簡單的隨機決定採用哪一個背景音樂。而後調用runGame()，當遊戲失敗，runGame()就會返回到main()函數，這時會中止背景音樂和顯示遊戲失敗的畫面。
當遊戲者按下一個鍵，showTextScreen()顯示遊戲失敗的函數就會返回。遊戲循環會再次開始而後繼續下一次遊戲。
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()
在遊戲開始和方塊掉落以前，咱們須要初始化一些跟遊戲開始相關的變量。fallingPiece變量被賦值成當前掉落的變量，nextPiece變量被賦值成遊戲者能夠在屏幕NEXT區域看見的下一個方塊。
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()
這部分包含了當方塊往底部掉落時的的全部代碼。fallingPiece變量在方塊着陸後被設置成None。這意味着nextPiece變量中的下一個方塊應該被賦值給fallingPiece變量，而後一個隨機的方塊又會被賦值給nextPiece變量。lastFallTime變量也被賦值成當前時間，這樣咱們就能夠經過fallFreq變量控制方塊下落的頻率。
來自getNewPiece函數的方塊只有一部分被放置在方框區域中。可是若是這是一個非法的位置，好比此時遊戲方框已經被填滿（isVaildPostion()函數返回False），那麼咱們就知道方框已經滿了，遊戲者輸掉了遊戲。當這些發生時，runGame()函數就會返回。
事件處理循環
事件循環主要處理當翻轉方塊，移動方塊時或者暫停遊戲時的一些事情。
暫停遊戲
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()
若是遊戲者按下P鍵，遊戲就會暫停。咱們應該隱藏掉遊戲界面以防止遊戲者做弊（不然遊戲者會看着畫面思考怎麼處理方塊），用DISPLAYSURF.fill(BGCOLOR)就能夠實現這個效果。注意的是咱們還要保存一些時間變量值。
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
中止按下方向鍵或ASD鍵會把moveLeft,moveRight,movingDown變量設置爲False.,代表遊戲者再也不想要在此方向上移動方塊。後面的代碼會基於moving變量處理一些事情。注意的上方向鍵和W鍵是用來翻轉方塊的而不是移動方塊。這就是爲何沒有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()
當左方向鍵按下（並且往左移動是有效的，經過調用isVaildPosition()函數知道的），那麼咱們應該改變一個方塊的位置使其向左移動一個經過讓rallingPiece['x']減1.isVaildPosition()函數有個參數選項是adjX和adjY.日常，isVaildPostion()函數檢查方塊的位置經過函數的第二個參數的傳遞。然而，有時咱們不想檢查方塊當前的位置，而是偏離當前方向幾個格子的位置。
好比adjX=-1，則表示向左移動一個格子後方塊的位置，爲+1則表示向右移動一個格子後的位置。adjY同理如此。
movingLeft變量會被設置爲True，確保方塊不會向右移動，此時movingRight變量設置爲False。同時須要更新lastMoveSidewaysTime的值。
這個lastMoveSidewaysTime變量設置的緣由是這樣。由於遊戲者有可能一直按着方向鍵讓其方塊移動。若是moveLeft被設置爲True，程序就會知道方向左鍵已經被按下。若是在lastMoveSidewaysTime變量儲存的時間基礎上，0.15秒（儲存在MOVESIDEAYSFREQ變量中）過去後，那麼此時程序就會將方塊再次向左移動一個格子。
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']])
若是方向鍵上或W鍵被按下，那麼就會翻轉方塊。上面的代碼作的就是將儲存在fallingPiece字典中的‘rotation’鍵的鍵值加1.然而，當增長的'rotation'鍵值大於全部當前類型方塊的形狀的數目的話（此變量儲存在len(SHAPES[fallingPiece['shape']])變量中），那麼它翻轉到最初的形狀。
if not isValidPosition(board, fallingPiece):
fallingPiece['rotation'] = (fallingPiece['rotation'] - 1) % len(PIECES[fallingPiece['shape']])若是翻轉後的形狀無效由於其中的一些小方塊已經超過邊框的範圍，那麼咱們就要把它變回原來的形狀經過將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']])
這段代碼與上面以前的那段代碼是一個意思，不一樣的是這段代碼是當遊戲者按下Q鍵時翻轉方塊朝相反的方向。這裏咱們減去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()若是下鍵被按下，遊戲者此時但願方塊降低的比日常快。fallingPiece['y'] += 1使方塊下落一個格子（前提是這是一個有效的下落）moveDown被設置爲True，lastMoceDownTime變量也被設置爲當前時間。這個變量之後將被檢查當方向下鍵一直按下時從而保證方塊以一個比日常快的速率降低。
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
當遊戲者按下空格鍵，方塊將會迅速的下落至着陸。程序首先須要找出到它着陸須要降低個多少個格子。其中有關moving的三個變量都要被設置爲False（保證程序後面部分的代碼知道遊戲者已經中止了按下全部的方向鍵）。
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方向鍵時的狀況。
若是用戶按住鍵超過0.15秒。那麼表達式(movingLeft or movingRight) and time.time() - lastMoveSidewaysTime > MOVESIDEWAYSFREQ:返回True。這樣的話咱們就能夠移動方塊向左或向右移動一個格子。
這個作法是很用的，由於若是用戶重複的按下方向鍵讓方塊移動多個格子是很煩人的。好的作法是，用戶能夠按住方向鍵讓方塊保持移動直到鬆開鍵爲止。最後別忘了更新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很少。
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() 方塊天然下落的速率由lastFallTime變量決定。若是自從上個方塊掉落了一個格子後過去了足夠的時間，那麼上面代碼就會再讓方塊移動一個格子。
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