500行代码写一个俄罗斯方块游戏
导读：本文我们要制作一个俄罗斯方块游戏。
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：
-
用
QtCore.QBasicTimer()QtCore.QBasicTimer()创建一个游戏循环 -
模型是一直下落的
-
模型的运动是以小块为基础单位的，不是按像素
-
从数学意义上来说，模型就是就是一串数字而已
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
99
100
101 def squareHeight(self):
102 '''returns the height of one square'''
103
104 return self.contentsRect().height() // Board.BoardHeight
105
106
107 def start(self):
108 '''starts game'''
109
110 if self.isPaused:
111 return
112
113 self.isStarted = True
114 self.isWaitingAfterLine = False
115 self.numLinesRemoved = 0
116 self.clearBoard()
117
118 self.msg2Statusbar.emit(str(self.numLinesRemoved))
119
120 self.newPiece()
121 self.timer.start(Board.Speed, self)
122
123
124 def pause(self):
125 '''pauses game'''
126
127 if not self.isStarted:
128 return
129
130 self.isPaused = not self.isPaused
131
132 if self.isPaused:
133 self.timer.stop()
134 self.msg2Statusbar.emit("paused")
135
136 else:
137 self.timer.start(Board.Speed, self)
138 self.msg2Statusbar.emit(str(self.numLinesRemoved))
139
140 self.update()
141
142
143 def paintEvent(self, event):
144 '''paints all shapes of the game'''
145
146 painter = QPainter(self)
147 rect = self.contentsRect()
148
149 boardTop = rect.bottom() - Board.BoardHeight * self.squareHeight()
150
151 for i in range(Board.BoardHeight):
152 for j in range(Board.BoardWidth):
153 shape = self.shapeAt(j, Board.BoardHeight - i - 1)
154
155 if shape != Tetrominoe.NoShape:
156 self.drawSquare(painter,
157 rect.left() + j * self.squareWidth(),
158 boardTop + i * self.squareHeight(), shape)
159
160 if self.curPiece.shape() != Tetrominoe.NoShape:
161
162 for i in range(4):
163
164 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())
169
170
171 def keyPressEvent(self, event):
172 '''processes key press events'''
173
174 if not self.isStarted or self.curPiece.shape() == Tetrominoe.NoShape:
175 super(Board, self).keyPressEvent(event)
176 return
177
178 key = event.key()
179
180 if key == Qt.Key_P:
181 self.pause()
182 return
183
184 if self.isPaused:
185 return
186
187 elif key == Qt.Key_Left:
188 self.tryMove(self.curPiece, self.curX - 1, self.curY)
189
190 elif key == Qt.Key_Right:
191 self.tryMove(self.curPiece, self.curX + 1, self.curY)
192
193 elif key == Qt.Key_Down:
194 self.tryMove(self.curPiece.rotateRight(), self.curX, self.curY)
195
196 elif key == Qt.Key_Up:
197 self.tryMove(self.curPiece.rotateLeft(), self.curX, self.curY)
198
199 elif key == Qt.Key_Space:
200 self.dropDown()
201
202 elif key == Qt.Key_D:
203 self.oneLineDown()
204
205 else:
206 super(Board, self).keyPressEvent(event)
207
208
209 def timerEvent(self, event):
210 '''handles timer event'''
211
212 if event.timerId() == self.timer.timerId():
213
214 if self.isWaitingAfterLine:
215 self.isWaitingAfterLine = False
216 self.newPiece()
217 else:
218 self.oneLineDown()
219
220 else:
221 super(Board, self).timerEvent(event)
222
223
224 def clearBoard(self):
225 '''clears shapes from the board'''
226
227 for i in range(Board.BoardHeight * Board.BoardWidth):
228 self.board.append(Tetrominoe.NoShape)
229
230
231 def dropDown(self):
232 '''drops down a shape'''
233
234 newY = self.curY
235
236 while newY > 0:
237
238 if not self.tryMove(self.curPiece, self.curX, newY - 1):
239 break
240
241 newY -= 1
242
243 self.pieceDropped()
244
245
246 def oneLineDown(self):
247 '''goes one line down with a shape'''
248
249 if not self.tryMove(self.curPiece, self.curX, self.curY - 1):
250 self.pieceDropped()
251
252
253 def pieceDropped(self):
254 '''after dropping shape, remove full lines and create new shape'''
255
256 for i in range(4):
257
258 x = self.curX + self.curPiece.x(i)
259 y = self.curY - self.curPiece.y(i)
260 self.setShapeAt(x, y, self.curPiece.shape())
261
262 self.removeFullLines()
263
264 if not self.isWaitingAfterLine:
265 self.newPiece()
266
267
268 def removeFullLines(self):
269 '''removes all full lines from the board'''
270
271 numFullLines = 0
272 rowsToRemove = []
273
274 for i in range(Board.BoardHeight):
275
276 n = 0
277 for j in range(Board.BoardWidth):
278 if not self.shapeAt(j, i) == Tetrominoe.NoShape:
279 n = n + 1
280
281 if n == 10:
282 rowsToRemove.append(i)
283
284 rowsToRemove.reverse()
285
286
287 for m in rowsToRemove:
288
289 for k in range(m, Board.BoardHeight):
290 for l in range(Board.BoardWidth):
291 self.setShapeAt(l, k, self.shapeAt(l, k + 1))
292
293 numFullLines = numFullLines + len(rowsToRemove)
294
295 if numFullLines > 0:
296
297 self.numLinesRemoved = self.numLinesRemoved + numFullLines
298 self.msg2Statusbar.emit(str(self.numLinesRemoved))
299
300 self.isWaitingAfterLine = True
301 self.curPiece.setShape(Tetrominoe.NoShape)
302 self.update()
303
304
305 def newPiece(self):
306 '''creates a new shape'''
307
308 self.curPiece = Shape()
309 self.curPiece.setRandomShape()
310 self.curX = Board.BoardWidth // 2 + 1
311 self.curY = Board.BoardHeight - 1 + self.curPiece.minY()
312
313 if not self.tryMove(self.curPiece, self.curX, self.curY):
314
315 self.curPiece.setShape(Tetrominoe.NoShape)
316 self.timer.stop()
317 self.isStarted = False
318 self.msg2Statusbar.emit("Game over")
319
320
321
322 def tryMove(self, newPiece, newX, newY):
323 '''tries to move a shape'''
324
325 for i in range(4):
326
327 x = newX + newPiece.x(i)
328 y = newY - newPiece.y(i)
329
330 if x < 0 or x >= Board.BoardWidth or y < 0 or y >= Board.BoardHeight:
331 return False
332
333 if self.shapeAt(x, y) != Tetrominoe.NoShape:
334 return False
335
336 self.curPiece = newPiece
337 self.curX = newX
338 self.curY = newY
339 self.update()
340
341 return True
342
343
344 def drawSquare(self, painter, x, y, shape):
345 '''draws a square of a shape'''
346
347 colorTable = [0x000000, 0xCC6666, 0x66CC66, 0x6666CC,
348 0xCCCC66, 0xCC66CC, 0x66CCCC, 0xDAAA00]
349
350 color = QColor(colorTable[shape])
351 painter.fillRect(x + 1, y + 1, self.squareWidth() - 2,
352 self.squareHeight() - 2, color)
353
354 painter.setPen(color.lighter())
355 painter.drawLine(x, y + self.squareHeight() - 1, x, y)
356 painter.drawLine(x, y, x + self.squareWidth() - 1, y)
357
358 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)
363
364
365class Tetrominoe(object):
366
367 NoShape = 0
368 ZShape = 1
369 SShape = 2
370 LineShape = 3
371 TShape = 4
372 SquareShape = 5
373 LShape = 6
374 MirroredLShape = 7
375
376
377class Shape(object):
378
379 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 )
389
390 def __init__(self):
391
392 self.coords = [[0,0] for i in range(4)]
393 self.pieceShape = Tetrominoe.NoShape
394
395 self.setShape(Tetrominoe.NoShape)
396
397
398 def shape(self):
399 '''returns shape'''
400
401 return self.pieceShape
402
403
404 def setShape(self, shape):
405 '''sets a shape'''
406
407 table = Shape.coordsTable[shape]
408
409 for i in range(4):
410 for j in range(2):
411 self.coords[i][j] = table[i][j]
412
413 self.pieceShape = shape
414
415
416 def setRandomShape(self):
417 '''chooses a random shape'''
418
419 self.setShape(random.randint(1, 7))
420
421
422 def x(self, index):
423 '''returns x coordinate'''
424
425 return self.coords[index][0]
426
427
428 def y(self, index):
429 '''returns y coordinate'''
430
431 return self.coords[index][1]
432
433
434 def setX(self, index, x):
435 '''sets x coordinate'''
436
437 self.coords[index][0] = x
438
439
440 def setY(self, index, y):
441 '''sets y coordinate'''
442
443 self.coords[index][1] = y
444
445
446 def minX(self):
447 '''returns min x value'''
448
449 m = self.coords[0][0]
450 for i in range(4):
451 m = min(m, self.coords[i][0])
452
453 return m
454
455
456 def maxX(self):
457 '''returns max x value'''
458
459 m = self.coords[0][0]
460 for i in range(4):
461 m = max(m, self.coords[i][0])
462
463 return m
464
465
466 def minY(self):
467 '''returns min y value'''
468
469 m = self.coords[0][1]
470 for i in range(4):
471 m = min(m, self.coords[i][1])
472
473 return m
474
475
476 def maxY(self):
477 '''returns max y value'''
478
479 m = self.coords[0][1]
480 for i in range(4):
481 m = max(m, self.coords[i][1])
482
483 return m
484
485
486 def rotateLeft(self):
487 '''rotates shape to the left'''
488
489 if self.pieceShape == Tetrominoe.SquareShape:
490 return self
491
492 result = Shape()
493 result.pieceShape = self.pieceShape
494
495 for i in range(4):
496
497 result.setX(i, self.y(i))
498 result.setY(i, -self.x(i))
499
500 return result
501
502
503 def rotateRight(self):
504 '''rotates shape to the right'''
505
506 if self.pieceShape == Tetrominoe.SquareShape:
507 return self
508
509 result = Shape()
510 result.pieceShape = self.pieceShape
511
512 for i in range(4):
513
514 result.setX(i, -self.y(i))
515 result.setY(i, self.x(i))
516
517 return result
518
519
520if __name__ == '__main__':
521
522 app = QApplication([])
523 tetris = Tetris()
524 sys.exit(app.exec_())
(代码可以左右滑动)
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：
来源：https://segmentfault.com/a/1190000017845103
