pyqt5开发之俄罗斯方块

  1 #!/usr/bin/python3
  2 # -*- coding: utf-8 -*-
  3 
  4 """
  5 ZetCode PyQt5 tutorial 
  6 
  7 This is a Tetris game clone.
  8 
  9 """
 10 
 11 from PyQt5.QtWidgets import QMainWindow, QFrame, QDesktopWidget, QApplication
 12 from PyQt5.QtCore import Qt, QBasicTimer, pyqtSignal
 13 from PyQt5.QtGui import QPainter, QColor 
 14 import sys, random
 15 
 16 class Tetris(QMainWindow):
 17 
 18     def __init__(self):
 19         super().__init__()
 20 
 21         self.initUI()
 22 
 23 
 24     def initUI(self):    
 25         '''initiates application UI'''
 26 
 27         self.tboard = Board(self)
 28         self.setCentralWidget(self.tboard)
 29 
 30         self.statusbar = self.statusBar()        
 31         self.tboard.msg2Statusbar[str].connect(self.statusbar.showMessage)
 32 
 33         self.tboard.start()
 34 
 35         self.resize(180, 380)
 36         self.center()
 37         self.setWindowTitle('Tetris')        
 38         self.show()
 39 
 40 
 41     def center(self):
 42         '''centers the window on the screen'''
 43 
 44         screen = QDesktopWidget().screenGeometry()
 45         size = self.geometry()
 46         self.move((screen.width()-size.width())/2, 
 47             (screen.height()-size.height())/2)
 48 
 49 
 50 class Board(QFrame):
 51 
 52     msg2Statusbar = pyqtSignal(str)
 53 
 54     BoardWidth = 10
 55     BoardHeight = 22
 56     Speed = 300
 57 
 58     def __init__(self, parent):
 59         super().__init__(parent)
 60 
 61         self.initBoard()
 62 
 63 
 64     def initBoard(self):     
 65         '''initiates board'''
 66 
 67         self.timer = QBasicTimer()
 68         self.isWaitingAfterLine = False
 69 
 70         self.curX = 0
 71         self.curY = 0
 72         self.numLinesRemoved = 0
 73         self.board = []
 74 
 75         self.setFocusPolicy(Qt.StrongFocus)
 76         self.isStarted = False
 77         self.isPaused = False
 78         self.clearBoard()
 79 
 80 
 81     def shapeAt(self, x, y):
 82         '''determines shape at the board position'''
 83 
 84         return self.board[(y * Board.BoardWidth) + x]
 85 
 86 
 87     def setShapeAt(self, x, y, shape):
 88         '''sets a shape at the board'''
 89 
 90         self.board[(y * Board.BoardWidth) + x] = shape
 91 
 92 
 93     def squareWidth(self):
 94         '''returns the width of one square'''
 95 
 96         return self.contentsRect().width() // Board.BoardWidth
 97 
 98 
 99     def squareHeight(self):
100         '''returns the height of one square'''
101 
102         return self.contentsRect().height() // Board.BoardHeight
103 
104 
105     def start(self):
106         '''starts game'''
107 
108         if self.isPaused:
109             return
110 
111         self.isStarted = True
112         self.isWaitingAfterLine = False
113         self.numLinesRemoved = 0
114         self.clearBoard()
115 
116         self.msg2Statusbar.emit(str(self.numLinesRemoved))
117 
118         self.newPiece()
119         self.timer.start(Board.Speed, self)
120 
121 
122     def pause(self):
123         '''pauses game'''
124 
125         if not self.isStarted:
126             return
127 
128         self.isPaused = not self.isPaused
129 
130         if self.isPaused:
131             self.timer.stop()
132             self.msg2Statusbar.emit("paused")
133 
134         else:
135             self.timer.start(Board.Speed, self)
136             self.msg2Statusbar.emit(str(self.numLinesRemoved))
137 
138         self.update()
139 
140 
141     def paintEvent(self, event):
142         '''paints all shapes of the game'''
143 
144         painter = QPainter(self)
145         rect = self.contentsRect()
146 
147         boardTop = rect.bottom() - Board.BoardHeight * self.squareHeight()
148 
149         for i in range(Board.BoardHeight):
150             for j in range(Board.BoardWidth):
151                 shape = self.shapeAt(j, Board.BoardHeight - i - 1)
152 
153                 if shape != Tetrominoe.NoShape:
154                     self.drawSquare(painter,
155                         rect.left() + j * self.squareWidth(),
156                         boardTop + i * self.squareHeight(), shape)
157 
158         if self.curPiece.shape() != Tetrominoe.NoShape:
159 
160             for i in range(4):
161 
162                 x = self.curX + self.curPiece.x(i)
163                 y = self.curY - self.curPiece.y(i)
164                 self.drawSquare(painter, rect.left() + x * self.squareWidth(),
165                     boardTop + (Board.BoardHeight - y - 1) * self.squareHeight(),
166                     self.curPiece.shape())
167 
168 
169     def keyPressEvent(self, event):
170         '''processes key press events'''
171 
172         if not self.isStarted or self.curPiece.shape() == Tetrominoe.NoShape:
173             super(Board, self).keyPressEvent(event)
174             return
175 
176         key = event.key()
177 
178         if key == Qt.Key_P:
179             self.pause()
180             return
181 
182         if self.isPaused:
183             return
184 
185         elif key == Qt.Key_Left:
186             self.tryMove(self.curPiece, self.curX - 1, self.curY)
187 
188         elif key == Qt.Key_Right:
189             self.tryMove(self.curPiece, self.curX + 1, self.curY)
190 
191         elif key == Qt.Key_Down:
192             self.tryMove(self.curPiece.rotateRight(), self.curX, self.curY)
193 
194         elif key == Qt.Key_Up:
195             self.tryMove(self.curPiece.rotateLeft(), self.curX, self.curY)
196 
197         elif key == Qt.Key_Space:
198             self.dropDown()
199 
200         elif key == Qt.Key_D:
201             self.oneLineDown()
202 
203         else:
204             super(Board, self).keyPressEvent(event)
205 
206 
207     def timerEvent(self, event):
208         '''handles timer event'''
209 
210         if event.timerId() == self.timer.timerId():
211 
212             if self.isWaitingAfterLine:
213                 self.isWaitingAfterLine = False
214                 self.newPiece()
215             else:
216                 self.oneLineDown()
217 
218         else:
219             super(Board, self).timerEvent(event)
220 
221 
222     def clearBoard(self):
223         '''clears shapes from the board'''
224 
225         for i in range(Board.BoardHeight * Board.BoardWidth):
226             self.board.append(Tetrominoe.NoShape)
227 
228 
229     def dropDown(self):
230         '''drops down a shape'''
231 
232         newY = self.curY
233 
234         while newY > 0:
235 
236             if not self.tryMove(self.curPiece, self.curX, newY - 1):
237                 break
238 
239             newY -= 1
240 
241         self.pieceDropped()
242 
243 
244     def oneLineDown(self):
245         '''goes one line down with a shape'''
246 
247         if not self.tryMove(self.curPiece, self.curX, self.curY - 1):
248             self.pieceDropped()
249 
250 
251     def pieceDropped(self):
252         '''after dropping shape, remove full lines and create new shape'''
253 
254         for i in range(4):
255 
256             x = self.curX + self.curPiece.x(i)
257             y = self.curY - self.curPiece.y(i)
258             self.setShapeAt(x, y, self.curPiece.shape())
259 
260         self.removeFullLines()
261 
262         if not self.isWaitingAfterLine:
263             self.newPiece()
264 
265 
266     def removeFullLines(self):
267         '''removes all full lines from the board'''
268 
269         numFullLines = 0
270         rowsToRemove = []
271 
272         for i in range(Board.BoardHeight):
273 
274             n = 0
275             for j in range(Board.BoardWidth):
276                 if not self.shapeAt(j, i) == Tetrominoe.NoShape:
277                     n = n + 1
278 
279             if n == 10:
280                 rowsToRemove.append(i)
281 
282         rowsToRemove.reverse()
283 
284 
285         for m in rowsToRemove:
286 
287             for k in range(m, Board.BoardHeight):
288                 for l in range(Board.BoardWidth):
289                         self.setShapeAt(l, k, self.shapeAt(l, k + 1))
290 
291         numFullLines = numFullLines + len(rowsToRemove)
292 
293         if numFullLines > 0:
294 
295             self.numLinesRemoved = self.numLinesRemoved + numFullLines
296             self.msg2Statusbar.emit(str(self.numLinesRemoved))
297 
298             self.isWaitingAfterLine = True
299             self.curPiece.setShape(Tetrominoe.NoShape)
300             self.update()
301 
302 
303     def newPiece(self):
304         '''creates a new shape'''
305 
306         self.curPiece = Shape()
307         self.curPiece.setRandomShape()
308         self.curX = Board.BoardWidth // 2 + 1
309         self.curY = Board.BoardHeight - 1 + self.curPiece.minY()
310 
311         if not self.tryMove(self.curPiece, self.curX, self.curY):
312 
313             self.curPiece.setShape(Tetrominoe.NoShape)
314             self.timer.stop()
315             self.isStarted = False
316             self.msg2Statusbar.emit("Game over")
317 
318 
319 
320     def tryMove(self, newPiece, newX, newY):
321         '''tries to move a shape'''
322 
323         for i in range(4):
324 
325             x = newX + newPiece.x(i)
326             y = newY - newPiece.y(i)
327 
328             if x < 0 or x >= Board.BoardWidth or y < 0 or y >= Board.BoardHeight:
329                 return False
330 
331             if self.shapeAt(x, y) != Tetrominoe.NoShape:
332                 return False
333 
334         self.curPiece = newPiece
335         self.curX = newX
336         self.curY = newY
337         self.update()
338 
339         return True
340 
341 
342     def drawSquare(self, painter, x, y, shape):
343         '''draws a square of a shape'''        
344 
345         colorTable = [0x000000, 0xCC6666, 0x66CC66, 0x6666CC,
346                       0xCCCC66, 0xCC66CC, 0x66CCCC, 0xDAAA00]
347 
348         color = QColor(colorTable[shape])
349         painter.fillRect(x + 1, y + 1, self.squareWidth() - 2, 
350             self.squareHeight() - 2, color)
351 
352         painter.setPen(color.lighter())
353         painter.drawLine(x, y + self.squareHeight() - 1, x, y)
354         painter.drawLine(x, y, x + self.squareWidth() - 1, y)
355 
356         painter.setPen(color.darker())
357         painter.drawLine(x + 1, y + self.squareHeight() - 1,
358             x + self.squareWidth() - 1, y + self.squareHeight() - 1)
359         painter.drawLine(x + self.squareWidth() - 1, 
360             y + self.squareHeight() - 1, x + self.squareWidth() - 1, y + 1)
361 
362 
363 class Tetrominoe(object):
364 
365     NoShape = 0
366     ZShape = 1
367     SShape = 2
368     LineShape = 3
369     TShape = 4
370     SquareShape = 5
371     LShape = 6
372     MirroredLShape = 7
373 
374 
375 class Shape(object):
376 
377     coordsTable = (
378         ((0, 0),     (0, 0),     (0, 0),     (0, 0)),
379         ((0, -1),    (0, 0),     (-1, 0),    (-1, 1)),
380         ((0, -1),    (0, 0),     (1, 0),     (1, 1)),
381         ((0, -1),    (0, 0),     (0, 1),     (0, 2)),
382         ((-1, 0),    (0, 0),     (1, 0),     (0, 1)),
383         ((0, 0),     (1, 0),     (0, 1),     (1, 1)),
384         ((-1, -1),   (0, -1),    (0, 0),     (0, 1)),
385         ((1, -1),    (0, -1),    (0, 0),     (0, 1))
386     )
387 
388     def __init__(self):
389 
390         self.coords = [[0,0] for i in range(4)]
391         self.pieceShape = Tetrominoe.NoShape
392 
393         self.setShape(Tetrominoe.NoShape)
394 
395 
396     def shape(self):
397         '''returns shape'''
398 
399         return self.pieceShape
400 
401 
402     def setShape(self, shape):
403         '''sets a shape'''
404 
405         table = Shape.coordsTable[shape]
406 
407         for i in range(4):
408             for j in range(2):
409                 self.coords[i][j] = table[i][j]
410 
411         self.pieceShape = shape
412 
413 
414     def setRandomShape(self):
415         '''chooses a random shape'''
416 
417         self.setShape(random.randint(1, 7))
418 
419 
420     def x(self, index):
421         '''returns x coordinate'''
422 
423         return self.coords[index][0]
424 
425 
426     def y(self, index):
427         '''returns y coordinate'''
428 
429         return self.coords[index][1]
430 
431 
432     def setX(self, index, x):
433         '''sets x coordinate'''
434 
435         self.coords[index][0] = x
436 
437 
438     def setY(self, index, y):
439         '''sets y coordinate'''
440 
441         self.coords[index][1] = y
442 
443 
444     def minX(self):
445         '''returns min x value'''
446 
447         m = self.coords[0][0]
448         for i in range(4):
449             m = min(m, self.coords[i][0])
450 
451         return m
452 
453 
454     def maxX(self):
455         '''returns max x value'''
456 
457         m = self.coords[0][0]
458         for i in range(4):
459             m = max(m, self.coords[i][0])
460 
461         return m
462 
463 
464     def minY(self):
465         '''returns min y value'''
466 
467         m = self.coords[0][1]
468         for i in range(4):
469             m = min(m, self.coords[i][1])
470 
471         return m
472 
473 
474     def maxY(self):
475         '''returns max y value'''
476 
477         m = self.coords[0][1]
478         for i in range(4):
479             m = max(m, self.coords[i][1])
480 
481         return m
482 
483 
484     def rotateLeft(self):
485         '''rotates shape to the left'''
486 
487         if self.pieceShape == Tetrominoe.SquareShape:
488             return self
489 
490         result = Shape()
491         result.pieceShape = self.pieceShape
492 
493         for i in range(4):
494 
495             result.setX(i, self.y(i))
496             result.setY(i, -self.x(i))
497 
498         return result
499 
500 
501     def rotateRight(self):
502         '''rotates shape to the right'''
503 
504         if self.pieceShape == Tetrominoe.SquareShape:
505             return self
506 
507         result = Shape()
508         result.pieceShape = self.pieceShape
509 
510         for i in range(4):
511 
512             result.setX(i, -self.y(i))
513             result.setY(i, self.x(i))
514 
515         return result
516 
517 
518 if __name__ == '__main__':
519 
520     app = QApplication([])
521     tetris = Tetris()    
522     sys.exit(app.exec_())

View Code

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。

self.tboard.start()

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 = 10
BoardHeight = 22
Speed = 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 = 0
self.curY = 0
self.numLinesRemoved = 0
self.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()

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

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：