01 俄罗斯方块 Tetris
俄罗斯方块游戏是世界上最流行的游戏之一。是由一名叫 Alexey Pajitnov 的俄罗斯程序员在 1985 年制作的，从那时起，这个游戏就风靡了各个游戏平台。
俄罗斯方块归类为下落块迷宫游戏。游戏有 7 个基本形状：S、Z、T、L、反向 L、直线、方块，每个形状都由 4 个方块组成，方块最终都会落到屏幕底部。所以玩家通过控制形状的左右位置和旋转，让每个形状都以合适的位置落下，如果有一行全部被方块填充，这行就会消失，并且得分。游戏结束的条件是有形状接触到了屏幕顶部。
方块展示：
PyQt5 是专门为创建图形界面产生的，里面一些专门为制作游戏而开发的组件，所以 PyQt5 是能制作小游戏的。
制作电脑游戏也是提高自己编程能力的一种很好的方式。
02 开发
没有图片，所以就自己用绘画画出来几个图形。每个游戏里都有数学模型的，这个也是。
开工之前：
代码由四个类组成：Tetris, Board, Tetrominoe 和 Shape。Tetris 类创建游戏，Board 是游戏主要逻辑。Tetrominoe 包含了所有的砖块，Shape 是所有砖块的代码。
1#!/usr/bin/python3 2# -*- coding: utf-8 -*- 3 4""" 5ZetCode PyQt5 tutorial 6This is a Tetris game clone. 7 8Author: Jan Bodnar 9Website: zetcode.com 10Last edited: August 2017 11""" 12 13from PyQt5.QtWidgets import QMainWindow, QFrame, QDesktopWidget, QApplication 14from PyQt5.QtCore import Qt, QBasicTimer, pyqtSignal 15from PyQt5.QtGui import QPainter, QColor 16import sys, random 17 18class Tetris(QMainWindow): 19 20 def __init__(self): 21 super().__init__() 22 23 self.initUI() 24 25 26 def initUI(self): 27 '''initiates application UI''' 28 29 self.tboard = Board(self) 30 self.setCentralWidget(self.tboard) 31 32 self.statusbar = self.statusBar() 33 self.tboard.msg2Statusbar[str].connect(self.statusbar.showMessage) 34 35 self.tboard.start() 36 37 self.resize(180, 380) 38 self.center() 39 self.setWindowTitle('Tetris') 40 self.show() 41 42 43 def center(self): 44 '''centers the window on the screen''' 45 46 screen = QDesktopWidget().screenGeometry() 47 size = self.geometry() 48 self.move((screen.width()-size.width())/2, 49 (screen.height()-size.height())/2) 50 51 52class Board(QFrame): 53 54 msg2Statusbar = pyqtSignal(str) 55 56 BoardWidth = 10 57 BoardHeight = 22 58 Speed = 300 59 60 def __init__(self, parent): 61 super().__init__(parent) 62 63 self.initBoard() 64 65 66 def initBoard(self): 67 '''initiates board''' 68 69 self.timer = QBasicTimer() 70 self.isWaitingAfterLine = False 71 72 self.curX = 0 73 self.curY = 0 74 self.numLinesRemoved = 0 75 self.board = [] 76 77 self.setFocusPolicy(Qt.StrongFocus) 78 self.isStarted = False 79 self.isPaused = False 80 self.clearBoard() 81 82 83 def shapeAt(self, x, y): 84 '''determines shape at the board position''' 85 86 return self.board[(y * Board.BoardWidth) + x] 87 88 89 def setShapeAt(self, x, y, shape): 90 '''sets a shape at the board''' 91 92 self.board[(y * Board.BoardWidth) + x] = shape 93 94 95 def squareWidth(self): 96 '''returns the width of one square''' 97 98 return self.contentsRect().width() // Board.BoardWidth 99100101 def squareHeight(self):102 '''returns the height of one square'''103104 return self.contentsRect().height() // Board.BoardHeight105106107 def start(self):108 '''starts game'''109110 if self.isPaused:111 return112113 self.isStarted = True114 self.isWaitingAfterLine = False115 self.numLinesRemoved = 0116 self.clearBoard()117118 self.msg2Statusbar.emit(str(self.numLinesRemoved))119120 self.newPiece()121 self.timer.start(Board.Speed, self)122123124 def pause(self):125 '''pauses game'''126127 if not self.isStarted:128 return129130 self.isPaused = not self.isPaused131132 if self.isPaused:133 self.timer.stop()134 self.msg2Statusbar.emit("paused")135136 else:137 self.timer.start(Board.Speed, self)138 self.msg2Statusbar.emit(str(self.numLinesRemoved))139140 self.update()141142143 def paintEvent(self, event):144 '''paints all shapes of the game'''145146 painter = QPainter(self)147 rect = self.contentsRect()148149 boardTop = rect.bottom() - Board.BoardHeight * self.squareHeight()150151 for i in range(Board.BoardHeight):152 for j in range(Board.BoardWidth):153 shape = self.shapeAt(j, Board.BoardHeight - i - 1)154155 if shape != Tetrominoe.NoShape:156 self.drawSquare(painter,157 rect.left() + j * self.squareWidth(),158 boardTop + i * self.squareHeight(), shape)159160 if self.curPiece.shape() != Tetrominoe.NoShape:161162 for i in range(4):163164 x = self.curX + self.curPiece.x(i)165 y = self.curY - self.curPiece.y(i)166 self.drawSquare(painter, rect.left() + x * self.squareWidth(),167 boardTop + (Board.BoardHeight - y - 1) * self.squareHeight(),168 self.curPiece.shape())169170171 def keyPressEvent(self, event):172 '''processes key press events'''173174 if not self.isStarted or self.curPiece.shape() == Tetrominoe.NoShape:175 super(Board, self).keyPressEvent(event)176 return177178 key = event.key()179180 if key == Qt.Key_P:181 self.pause()182 return183184 if self.isPaused:185 return186187 elif key == Qt.Key_Left:188 self.tryMove(self.curPiece, self.curX - 1, self.curY)189190 elif key == Qt.Key_Right:191 self.tryMove(self.curPiece, self.curX + 1, self.curY)192193 elif key == Qt.Key_Down:194 self.tryMove(self.curPiece.rotateRight(), self.curX, self.curY)195196 elif key == Qt.Key_Up:197 self.tryMove(self.curPiece.rotateLeft(), self.curX, self.curY)198199 elif key == Qt.Key_Space:200 self.dropDown()201202 elif key == Qt.Key_D:203 self.oneLineDown()204205 else:206 super(Board, self).keyPressEvent(event)207208209 def timerEvent(self, event):210 '''handles timer event'''211212 if event.timerId() == self.timer.timerId():213214 if self.isWaitingAfterLine:215 self.isWaitingAfterLine = False216 self.newPiece()217 else:218 self.oneLineDown()219220 else:221 super(Board, self).timerEvent(event)222223224 def clearBoard(self):225 '''clears shapes from the board'''226227 for i in range(Board.BoardHeight * Board.BoardWidth):228 self.board.append(Tetrominoe.NoShape)229230231 def dropDown(self):232 '''drops down a shape'''233234 newY = self.curY235236 while newY > 0:237238 if not self.tryMove(self.curPiece, self.curX, newY - 1):239 break240241 newY -= 1242243 self.pieceDropped()244245246 def oneLineDown(self):247 '''goes one line down with a shape'''248249 if not self.tryMove(self.curPiece, self.curX, self.curY - 1):250 self.pieceDropped()251252253 def pieceDropped(self):254 '''after dropping shape, remove full lines and create new shape'''255256 for i in range(4):257258 x = self.curX + self.curPiece.x(i)259 y = self.curY - self.curPiece.y(i)260 self.setShapeAt(x, y, self.curPiece.shape())261262 self.removeFullLines()263264 if not self.isWaitingAfterLine:265 self.newPiece()266267268 def removeFullLines(self):269 '''removes all full lines from the board'''270271 numFullLines = 0272 rowsToRemove = []273274 for i in range(Board.BoardHeight):275276 n = 0277 for j in range(Board.BoardWidth):278 if not self.shapeAt(j, i) == Tetrominoe.NoShape:279 n = n + 1280281 if n == 10:282 rowsToRemove.append(i)283284 rowsToRemove.reverse()285286287 for m in rowsToRemove:288289 for k in range(m, Board.BoardHeight):290 for l in range(Board.BoardWidth):291 self.setShapeAt(l, k, self.shapeAt(l, k + 1))292293 numFullLines = numFullLines + len(rowsToRemove)294295 if numFullLines > 0:296297 self.numLinesRemoved = self.numLinesRemoved + numFullLines298 self.msg2Statusbar.emit(str(self.numLinesRemoved))299300 self.isWaitingAfterLine = True301 self.curPiece.setShape(Tetrominoe.NoShape)302 self.update()303304305 def newPiece(self):306 '''creates a new shape'''307308 self.curPiece = Shape()309 self.curPiece.setRandomShape()310 self.curX = Board.BoardWidth // 2 + 1311 self.curY = Board.BoardHeight - 1 + self.curPiece.minY()312313 if not self.tryMove(self.curPiece, self.curX, self.curY):314315 self.curPiece.setShape(Tetrominoe.NoShape)316 self.timer.stop()317 self.isStarted = False318 self.msg2Statusbar.emit("Game over")319320321322 def tryMove(self, newPiece, newX, newY):323 '''tries to move a shape'''324325 for i in range(4):326327 x = newX + newPiece.x(i)328 y = newY - newPiece.y(i)329330 if x < 0 or x >= Board.BoardWidth or y < 0 or y >= Board.BoardHeight:331 return False332333 if self.shapeAt(x, y) != Tetrominoe.NoShape:334 return False335336 self.curPiece = newPiece337 self.curX = newX338 self.curY = newY339 self.update()340341 return True342343344 def drawSquare(self, painter, x, y, shape):345 '''draws a square of a shape'''346347 colorTable = [0x000000, 0xCC6666, 0x66CC66, 0x6666CC,348 0xCCCC66, 0xCC66CC, 0x66CCCC, 0xDAAA00]349350 color = QColor(colorTable[shape])351 painter.fillRect(x + 1, y + 1, self.squareWidth() - 2,352 self.squareHeight() - 2, color)353354 painter.setPen(color.lighter())355 painter.drawLine(x, y + self.squareHeight() - 1, x, y)356 painter.drawLine(x, y, x + self.squareWidth() - 1, y)357358 painter.setPen(color.darker())359 painter.drawLine(x + 1, y + self.squareHeight() - 1,360 x + self.squareWidth() - 1, y + self.squareHeight() - 1)361 painter.drawLine(x + self.squareWidth() - 1,362 y + self.squareHeight() - 1, x + self.squareWidth() - 1, y + 1)363364365class Tetrominoe(object):366367 NoShape = 0368 ZShape = 1369 SShape = 2370 LineShape = 3371 TShape = 4372 SquareShape = 5373 LShape = 6374 MirroredLShape = 7375376377class Shape(object):378379 coordsTable = (380 ((0, 0), (0, 0), (0, 0), (0, 0)),381 ((0, -1), (0, 0), (-1, 0), (-1, 1)),382 ((0, -1), (0, 0), (1, 0), (1, 1)),383 ((0, -1), (0, 0), (0, 1), (0, 2)),384 ((-1, 0), (0, 0), (1, 0), (0, 1)),385 ((0, 0), (1, 0), (0, 1), (1, 1)),386 ((-1, -1), (0, -1), (0, 0), (0, 1)),387 ((1, -1), (0, -1), (0, 0), (0, 1))388 )389390 def __init__(self):391392 self.coords = [[0,0] for i in range(4)]393 self.pieceShape = Tetrominoe.NoShape394395 self.setShape(Tetrominoe.NoShape)396397398 def shape(self):399 '''returns shape'''400401 return self.pieceShape402403404 def setShape(self, shape):405 '''sets a shape'''406407 table = Shape.coordsTable[shape]408409 for i in range(4):410 for j in range(2):411 self.coords[i][j] = table[i][j]412413 self.pieceShape = shape414415416 def setRandomShape(self):417 '''chooses a random shape'''418419 self.setShape(random.randint(1, 7))420421422 def x(self, index):423 '''returns x coordinate'''424425 return self.coords[index][0]426427428 def y(self, index):429 '''returns y coordinate'''430431 return self.coords[index][1]432433434 def setX(self, index, x):435 '''sets x coordinate'''436437 self.coords[index][0] = x438439440 def setY(self, index, y):441 '''sets y coordinate'''442443 self.coords[index][1] = y444445446 def minX(self):447 '''returns min x value'''448449 m = self.coords[0][0]450 for i in range(4):451 m = min(m, self.coords[i][0])452453 return m454455456 def maxX(self):457 '''returns max x value'''458459 m = self.coords[0][0]460 for i in range(4):461 m = max(m, self.coords[i][0])462463 return m464465466 def minY(self):467 '''returns min y value'''468469 m = self.coords[0][1]470 for i in range(4):471 m = min(m, self.coords[i][1])472473 return m474475476 def maxY(self):477 '''returns max y value'''478479 m = self.coords[0][1]480 for i in range(4):481 m = max(m, self.coords[i][1])482483 return m484485486 def rotateLeft(self):487 '''rotates shape to the left'''488489 if self.pieceShape == Tetrominoe.SquareShape:490 return self491492 result = Shape()493 result.pieceShape = self.pieceShape494495 for i in range(4):496497 result.setX(i, self.y(i))498 result.setY(i, -self.x(i))499500 return result501502503 def rotateRight(self):504 '''rotates shape to the right'''505506 if self.pieceShape == Tetrominoe.SquareShape:507 return self508509 result = Shape()510 result.pieceShape = self.pieceShape511512 for i in range(4):513514 result.setX(i, -self.y(i))515 result.setY(i, self.x(i))516517 return result518519520if __name__ == '__main__':521522 app = QApplication([])523 tetris = Tetris()524 sys.exit(app.exec_())
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游戏很简单，所以也就很好理解。程序加载之后游戏也就直接开始了，可以用 P 键暂停游戏，空格键让方块直接落到最下面。游戏的速度是固定的，并没有实现加速的功能。分数就是游戏中消除的行数。
self.tboard = Board(self)self.setCentralWidget(self.tboard)
创建了一个 Board 类的实例，并设置为应用的中心组件。
self.statusbar = self.statusBar()self.tboard.msg2Statusbar[str].connect(self.statusbar.showMessage)
创建一个statusbar来显示三种信息：消除的行数，游戏暂停状态或者游戏结束状态。msg2Statusbar是一个自定义的信号，用在（和）Board 类（交互），showMessage()方法是一个内建的，用来在 statusbar 上显示信息的方法。
初始化游戏：
class Board(QFrame): msg2Statusbar = pyqtSignal(str)...
创建了一个自定义信号msg2Statusbar，当我们想往statusbar里显示信息的时候，发出这个信号就行了。
BoardWidth = 10BoardHeight = 22Speed = 300
这些是Board类的变量。BoardWidth和BoardHeight分别是 board 的宽度和高度。Speed是游戏的速度，每 300ms 出现一个新的方块。
...self.curX = 0self.curY = 0self.numLinesRemoved = 0self.board = []...
在initBoard()里初始化了一些重要的变量。self.board定义了方块的形状和位置，取值范围是 0-7。
def shapeAt(self, x, y): return self.board[(y * Board.BoardWidth) + x]
shapeAt()决定了 board 里方块的的种类。
def squareWidth(self): return self.contentsRect().width() // Board.BoardWidth
board 的大小可以动态的改变。所以方格的大小也应该随之变化。squareWidth()计算并返回每个块应该占用多少像素--也即Board.BoardWidth。
def pause(self): '''pauses game'''
if not self.isStarted: return
self.isPaused = not self.isPaused
if self.isPaused: self.timer.stop() self.msg2Statusbar.emit("paused")
else: self.timer.start(Board.Speed, self) self.msg2Statusbar.emit(str(self.numLinesRemoved))
self.update()
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pause()方法用来暂停游戏，停止计时并在statusbar上显示一条信息。
def paintEvent(self, event): '''paints all shapes of the game''' painter = QPainter(self) rect = self.contentsRect()...
渲染是在 paintEvent()方法里发生的QPainter负责 PyQt5 里所有低级绘画操作。
for i in range(Board.BoardHeight): for j in range(Board.BoardWidth): shape = self.shapeAt(j, Board.BoardHeight - i - 1) if shape != Tetrominoe.NoShape: self.drawSquare(painter, rect.left() + j * self.squareWidth(), boardTop + i * self.squareHeight(), shape)
渲染游戏分为两步。第一步是先画出所有已经落在最下面的的图，这些保存在self.board里。可以使用shapeAt()查看这个这个变量。
if self.curPiece.shape() != Tetrominoe.NoShape: for i in range(4): x = self.curX + self.curPiece.x(i) y = self.curY - self.curPiece.y(i) self.drawSquare(painter, rect.left() + x * self.squareWidth(), boardTop + (Board.BoardHeight - y - 1) * self.squareHeight(), self.curPiece.shape())
第二步是画出更在下落的方块。
elif key == Qt.Key_Right: self.tryMove(self.curPiece, self.curX + 1, self.curY)
在keyPressEvent()方法获得用户按下的按键。如果按下的是右方向键，就尝试把方块向右移动，说尝试是因为有可能到边界不能移动了。
elif key == Qt.Key_Up: self.tryMove(self.curPiece.rotateLeft(), self.curX, self.curY)
上方向键是把方块向左旋转一下
elif key == Qt.Key_Space: self.dropDown()
空格键会直接把方块放到底部
elif key == Qt.Key_D: self.oneLineDown()
D 键是加速一次下落速度。
def tryMove(self, newPiece, newX, newY): for i in range(4): x = newX + newPiece.x(i) y = newY - newPiece.y(i) if x < 0 or x >= Board.BoardWidth or y < 0 or y >= Board.BoardHeight: return False if self.shapeAt(x, y) != Tetrominoe.NoShape: return False self.curPiece = newPiece self.curX = newX self.curY = newY self.update() return True
tryMove()是尝试移动方块的方法。如果方块已经到达 board 的边缘或者遇到了其他方块，就返回 False。否则就把方块下落到想要
def timerEvent(self, event): if event.timerId() == self.timer.timerId(): if self.isWaitingAfterLine: self.isWaitingAfterLine = False self.newPiece() else: self.oneLineDown() else: super(Board, self).timerEvent(event)
在计时器事件里，要么是等一个方块下落完之后创建一个新的方块，要么是让一个方块直接落到底（move a falling piece one line down）。
def clearBoard(self): for i in range(Board.BoardHeight * Board.BoardWidth): self.board.append(Tetrominoe.NoShape)
clearBoard()方法通过Tetrominoe.NoShape清空broad。
def removeFullLines(self): numFullLines = 0 rowsToRemove = [] for i in range(Board.BoardHeight): n = 0 for j in range(Board.BoardWidth): if not self.shapeAt(j, i) == Tetrominoe.NoShape: n = n + 1 if n == 10: rowsToRemove.append(i) rowsToRemove.reverse() for m in rowsToRemove: for k in range(m, Board.BoardHeight): for l in range(Board.BoardWidth): self.setShapeAt(l, k, self.shapeAt(l, k + 1)) numFullLines = numFullLines + len(rowsToRemove)...
如果方块碰到了底部，就调用removeFullLines()方法，找到所有能消除的行消除它们。消除的具体动作就是把符合条件的行消除掉之后，再把它上面的行下降一行。注意移除满行的动作是倒着来的，因为我们是按照重力来表现游戏的，如果不这样就有可能出现有些方块浮在空中的现象。
def newPiece(self): self.curPiece = Shape() self.curPiece.setRandomShape() self.curX = Board.BoardWidth // 2 + 1 self.curY = Board.BoardHeight - 1 + self.curPiece.minY() if not self.tryMove(self.curPiece, self.curX, self.curY): self.curPiece.setShape(Tetrominoe.NoShape) self.timer.stop() self.isStarted = False self.msg2Statusbar.emit("Game over")
newPiece()方法是用来创建形状随机的方块。如果随机的方块不能正确的出现在预设的位置，游戏结束。
class Tetrominoe(object): NoShape = 0 ZShape = 1 SShape = 2 LineShape = 3 TShape = 4 SquareShape = 5 LShape = 6 MirroredLShape = 7
Tetrominoe类保存了所有方块的形状。我们还定义了一个NoShape的空形状。
Shape 类保存类方块内部的信息。
class Shape(object): coordsTable = (
((0, 0), (0, 0), (0, 0), (0, 0)),
((0, -1), (0, 0), (-1, 0), (-1, 1)),
...
)...
coordsTable 元组保存了所有的方块形状的组成。是一个构成方块的坐标模版。
self.coords = [[0,0] for i in range(4)]
上面创建了一个新的空坐标数组，这个数组将用来保存方块的坐标。
坐标系示意图：
上面的图片可以帮助我们更好的理解坐标值的意义。比如元组(0, -1), (0, 0), (-1, 0), (-1, -1)代表了一个 Z 形状的方块。这个图表就描绘了这个形状。
def rotateLeft(self):
if self.pieceShape == Tetrominoe.SquareShape: return self
result = Shape() result.pieceShape = self.pieceShape
for i in range(4):
result.setX(i, self.y(i)) result.setY(i, -self.x(i))
return result
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rotateLeft()方法向右旋转一个方块。正方形的方块就没必要旋转，就直接返回了。其他的是返回一个新的，能表示这个形状旋转了的坐标。
程序展示：
来源：
https://segmentfault.com/a/1190000017845103
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