ZetCode

PySide中的俄罗斯方块游戏

最后修改于 2023 年 10 月 18 日

创建一个电脑游戏是具有挑战性的。迟早,程序员总有一天会想创建一个电脑游戏。事实上,许多人对编程感兴趣,因为他们玩游戏并想创建自己的游戏。创建一个电脑游戏将有助于提高你的编程技能。

俄罗斯方块

俄罗斯方块游戏是有史以来最受欢迎的电脑游戏之一。这款游戏最初由俄罗斯程序员Alexey Pajitnov于1985年设计和编程。从那时起,俄罗斯方块游戏几乎在每个电脑平台上都有很多变体。 甚至我的手机也有一个修改版的俄罗斯方块游戏。

俄罗斯方块被称为下落方块益智游戏。在这个游戏中,我们有七种不同的形状,称为tetrominoes。分别是S形、Z形、T形、L形、线形、镜像L形和方形。每种形状都由四个正方形组成。这些形状正在从游戏板上落下。俄罗斯方块游戏的目标是移动和旋转这些形状,使它们尽可能地贴合。如果我们设法形成一行,该行就会被摧毁并且我们得分。我们玩俄罗斯方块游戏直到顶部填满。

Tetrominoes
图:俄罗斯方块

PySide是一个用于创建应用程序的工具包。还有其他库专门用于创建电脑游戏。尽管如此,PySide和其他应用程序工具包也可以用于创建游戏。

开发

我们没有为我们的俄罗斯方块游戏准备图像,我们使用PySide编程工具包中提供的绘图API来绘制tetrominoes。在每个电脑游戏的背后,都有一个数学模型。俄罗斯方块也是如此。

游戏背后的一些想法

#!/usr/bin/python

"""
ZetCode PySide tutorial

This is a simple Tetris clone
in PySide.

author: Jan Bodnar
website: zetcode.com
last edited: August 2011
"""

import sys, random
from PySide import QtCore, QtGui

class Communicate(QtCore.QObject):
    
    msgToSB = QtCore.Signal(str)

class Tetris(QtGui.QMainWindow):
    
    def __init__(self):
        super(Tetris, self).__init__()

        self.setGeometry(300, 300, 180, 380)
        self.setWindowTitle('Tetris')
        self.Tetrisboard = Board(self)

        self.setCentralWidget(self.Tetrisboard)

        self.statusbar = self.statusBar()
        self.Tetrisboard.c.msgToSB[str].connect(self.statusbar.showMessage)
            
        self.Tetrisboard.start()
        self.center()

    def center(self):
        
        screen = QtGui.QDesktopWidget().screenGeometry()
        size =  self.geometry()
        self.move((screen.width()-size.width())/2, 
            (screen.height()-size.height())/2)


class Board(QtGui.QFrame):
    
    BoardWidth = 10
    BoardHeight = 22
    Speed = 300

    def __init__(self, parent):
        super(Board, self).__init__()

        self.timer = QtCore.QBasicTimer()
        self.isWaitingAfterLine = False
        self.curPiece = Shape()
        self.nextPiece = Shape()
        self.curX = 0
        self.curY = 0
        self.numLinesRemoved = 0
        self.board = []

        self.setFocusPolicy(QtCore.Qt.StrongFocus)
        self.isStarted = False
        self.isPaused = False
        self.clearBoard()
        
        self.c = Communicate()

        self.nextPiece.setRandomShape()

    def shapeAt(self, x, y):
        return self.board[(y * Board.BoardWidth) + x]

    def setShapeAt(self, x, y, shape):
        self.board[(y * Board.BoardWidth) + x] = shape

    def squareWidth(self):
        return self.contentsRect().width() / Board.BoardWidth

    def squareHeight(self):
        return self.contentsRect().height() / Board.BoardHeight

    def start(self):
        if self.isPaused:
            return

        self.isStarted = True
        self.isWaitingAfterLine = False
        self.numLinesRemoved = 0
        self.clearBoard()

        self.c.msgToSB.emit(str(self.numLinesRemoved))

        self.newPiece()
        self.timer.start(Board.Speed, self)

    def pause(self):
        
        if not self.isStarted:
            return

        self.isPaused = not self.isPaused
        
        if self.isPaused:
            self.timer.stop()
            self.c.msgToSB.emit("paused")
        else:
            self.timer.start(Board.Speed, self)
            self.c.msgToSB.emit(str(self.numLinesRemoved))

        self.update()

    def paintEvent(self, event):
        
        painter = QtGui.QPainter(self)
        rect = self.contentsRect()

        boardTop = rect.bottom() - Board.BoardHeight * self.squareHeight()

        for i in range(Board.BoardHeight):
            for j in range(Board.BoardWidth):
                shape = self.shapeAt(j, Board.BoardHeight - i - 1)
                if shape != Tetrominoes.NoShape:
                    self.drawSquare(painter,
                        rect.left() + j * self.squareWidth(),
                        boardTop + i * self.squareHeight(), shape)

        if self.curPiece.shape() != Tetrominoes.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())

    def keyPressEvent(self, event):
        
        if not self.isStarted or self.curPiece.shape() == Tetrominoes.NoShape:
            QtGui.QWidget.keyPressEvent(self, event)
            return

        key = event.key()
        
        if key == QtCore.Qt.Key_P:
            self.pause()
            return
        if self.isPaused:
            return
        elif key == QtCore.Qt.Key_Left:
            self.tryMove(self.curPiece, self.curX - 1, self.curY)
        elif key == QtCore.Qt.Key_Right:
            self.tryMove(self.curPiece, self.curX + 1, self.curY)
        elif key == QtCore.Qt.Key_Down:
            self.tryMove(self.curPiece.rotatedRight(), self.curX, self.curY)
        elif key == QtCore.Qt.Key_Up:
            self.tryMove(self.curPiece.rotatedLeft(), self.curX, self.curY)
        elif key == QtCore.Qt.Key_Space:
            self.dropDown()
        elif key == QtCore.Qt.Key_D:
            self.oneLineDown()
        else:
            QtGui.QWidget.keyPressEvent(self, event)

    def timerEvent(self, event):
        
        if event.timerId() == self.timer.timerId():
            if self.isWaitingAfterLine:
                self.isWaitingAfterLine = False
                self.newPiece()
            else:
                self.oneLineDown()
        else:
            QtGui.QFrame.timerEvent(self, event)

    def clearBoard(self):
        
        for i in range(Board.BoardHeight * Board.BoardWidth):
            self.board.append(Tetrominoes.NoShape)

    def dropDown(self):
        
        newY = self.curY
        while newY > 0:
            if not self.tryMove(self.curPiece, self.curX, newY - 1):
                break
            newY -= 1

        self.pieceDropped()

    def oneLineDown(self):
        
        if not self.tryMove(self.curPiece, self.curX, self.curY - 1):
            self.pieceDropped()

    def pieceDropped(self):
        
        for i in range(4):
            x = self.curX + self.curPiece.x(i)
            y = self.curY - self.curPiece.y(i)
            self.setShapeAt(x, y, self.curPiece.shape())

        self.removeFullLines()

        if not self.isWaitingAfterLine:
            self.newPiece()

    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) == Tetrominoes.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)

        if numFullLines > 0:
            self.numLinesRemoved = self.numLinesRemoved + numFullLines
            print self.numLinesRemoved
            self.c.msgToSB.emit(str(self.numLinesRemoved))
            self.isWaitingAfterLine = True
            self.curPiece.setShape(Tetrominoes.NoShape)
            self.update()

    def newPiece(self):
        
        self.curPiece = self.nextPiece
        self.nextPiece.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(Tetrominoes.NoShape)
            self.timer.stop()
            self.isStarted = False
            self.c.msgToSB.emit("Game over")

    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) != Tetrominoes.NoShape:
                return False

        self.curPiece = newPiece
        self.curX = newX
        self.curY = newY
        self.update()
        return True

    def drawSquare(self, painter, x, y, shape):
        
        colorTable = [0x000000, 0xCC6666, 0x66CC66, 0x6666CC,
                      0xCCCC66, 0xCC66CC, 0x66CCCC, 0xDAAA00]

        color = QtGui.QColor(colorTable[shape])
        painter.fillRect(x + 1, y + 1, self.squareWidth() - 2, 
            self.squareHeight() - 2, color)

        painter.setPen(color.lighter())
        painter.drawLine(x, y + self.squareHeight() - 1, x, y)
        painter.drawLine(x, y, x + self.squareWidth() - 1, y)

        painter.setPen(color.darker())
        painter.drawLine(x + 1, y + self.squareHeight() - 1,
            x + self.squareWidth() - 1, y + self.squareHeight() - 1)
        painter.drawLine(x + self.squareWidth() - 1, 
            y + self.squareHeight() - 1, x + self.squareWidth() - 1, y + 1)


class Tetrominoes(object):
    
    NoShape = 0
    ZShape = 1
    SShape = 2
    LineShape = 3
    TShape = 4
    SquareShape = 5
    LShape = 6
    MirroredLShape = 7


class Shape(object):
    
    coordsTable = (
        ((0, 0),     (0, 0),     (0, 0),     (0, 0)),
        ((0, -1),    (0, 0),     (-1, 0),    (-1, 1)),
        ((0, -1),    (0, 0),     (1, 0),     (1, 1)),
        ((0, -1),    (0, 0),     (0, 1),     (0, 2)),
        ((-1, 0),    (0, 0),     (1, 0),     (0, 1)),
        ((0, 0),     (1, 0),     (0, 1),     (1, 1)),
        ((-1, -1),   (0, -1),    (0, 0),     (0, 1)),
        ((1, -1),    (0, -1),    (0, 0),     (0, 1))
    )

    def __init__(self):
        
        self.coords = [[0,0] for i in range(4)]
        self.pieceShape = Tetrominoes.NoShape

        self.setShape(Tetrominoes.NoShape)

    def shape(self):
        return self.pieceShape

    def setShape(self, shape):
        
        table = Shape.coordsTable[shape]
        for i in range(4):
            for j in range(2):
                self.coords[i][j] = table[i][j]

        self.pieceShape = shape

    def setRandomShape(self):
        self.setShape(random.randint(1, 7))

    def x(self, index):
        return self.coords[index][0]

    def y(self, index):
        return self.coords[index][1]

    def setX(self, index, x):
        self.coords[index][0] = x

    def setY(self, index, y):
        self.coords[index][1] = y

    def minX(self):
        
        m = self.coords[0][0]
        for i in range(4):
            m = min(m, self.coords[i][0])

        return m

    def maxX(self):
        
        m = self.coords[0][0]
        for i in range(4):
            m = max(m, self.coords[i][0])

        return m

    def minY(self):
        
        m = self.coords[0][1]
        for i in range(4):
            m = min(m, self.coords[i][1])

        return m

    def maxY(self):
        
        m = self.coords[0][1]
        for i in range(4):
            m = max(m, self.coords[i][1])

        return m

    def rotatedLeft(self):
        
        if self.pieceShape == Tetrominoes.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

    def rotatedRight(self):
        
        if self.pieceShape == Tetrominoes.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

def main():
    
    app = QtGui.QApplication(sys.argv)
    t = Tetris()
    t.show()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

我已经简化了这个游戏,以便更容易理解。游戏在启动后立即开始。我们可以通过按下p键来暂停游戏。空格键会将俄罗斯方块直接放到最底部。游戏以恒定的速度进行,没有加速。分数是我们已经移除的行数。

self.statusbar = self.statusBar()
self.Tetrisboard.c.msgToSB[str].connect(self.statusbar.showMessage)	

我们创建一个状态栏,我们在其中显示消息。我们显示三种可能的消息。已经移除的行数。暂停消息和游戏结束消息。

...
self.curX = 0
self.curY = 0
self.numLinesRemoved = 0
self.board = []
...

在我们开始游戏循环之前,我们初始化一些重要的变量。self.board变量是一个从0到7的数字列表。它表示游戏中各种形状及其残留在游戏板上的位置。

for j in range(Board.BoardWidth):
    shape = self.shapeAt(j, Board.BoardHeight - i - 1)
    if shape != Tetrominoes.NoShape:
        self.drawSquare(painter,
            rect.left() + j * self.squareWidth(),
            boardTop + i * self.squareHeight(), shape)

游戏的绘制分为两个步骤。在第一步中,我们绘制所有形状,或已经掉落到游戏板底部的形状的残留。所有的方块都保存在self.board列表变量中。我们使用shapeAt()方法来访问它。

if self.curPiece.shape() != Tetrominoes.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())

下一步是绘制正在下落的实际方块。

elif key == QtCore.Qt.Key_Left:
    self.tryMove(self.curPiece, self.curX - 1, self.curY)
elif key == QtCore.Qt.Key_Right:
    self.tryMove(self.curPiece, self.curX + 1, self.curY)

keyPressEvent中,我们检查按下的按键。如果我们按下右箭头键,我们会尝试将方块向右移动。我们说尝试,因为方块可能无法移动。

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) != Tetrominoes.NoShape:
            return False

    self.curPiece = newPiece
    self.curX = newX
    self.curY = newY
    self.update()
    return True

tryMove方法中,我们尝试移动我们的形状。如果形状在游戏板的边缘或与另一个方块相邻,则返回false。否则,我们将当前的下落方块放置到新的位置。

def timerEvent(self, event):
    if event.timerId() == self.timer.timerId():
        if self.isWaitingAfterLine:
            self.isWaitingAfterLine = False
            self.newPiece()
        else:
            self.oneLineDown()
    else:
        QtGui.QFrame.timerEvent(self, event)

在计时器事件中,我们要么创建一个新的方块,在之前的方块落到底部之后,或者我们向下移动一个下落的方块一行。

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) == Tetrominoes.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))
...

如果方块落到底部,我们调用removeFullLines方法。首先我们找出所有完整的行。然后我们移除它们。我们通过将当前完整行上面的所有行移动到要移除的一行来完成此操作。请注意,我们颠倒了要移除的行的顺序。否则,它将无法正常工作。在我们的例子中,我们使用朴素的重力。这意味着方块可能会悬浮在空的间隙上方。

def newPiece(self):
    
    self.curPiece = self.nextPiece
    self.nextPiece.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(Tetrominoes.NoShape)
        self.timer.stop()
        self.isStarted = False
        self.c.msgToSB.emit("Game over")

newPiece方法随机创建一个新的俄罗斯方块。如果方块无法进入其初始位置,则游戏结束。

Shape类保存有关俄罗斯方块的信息。

self.coords = [[0,0] for i in range(4)]

创建时,我们创建一个空的坐标列表。该列表将保存俄罗斯方块的坐标。例如,这些元组(0,-1),(0,0),(1,0),(1,1)代表一个旋转的S形。下图说明了该形状。

Coordinates
图:坐标

当我们绘制当前的下落方块时,我们在self.curXself.curY位置绘制它。然后我们查看坐标表并绘制所有四个正方形。

Tetris
图:俄罗斯方块

这就是PySide中的俄罗斯方块游戏。