1 import random
2 import pygame
3 import sys
4 from pygame.locals import *
5
6 Snakespeed = 17
7 Window_Width = 800
8 Window_Height = 500
9 Cell_Size = 20 # Width and height of the cells
10 # Ensuring that the cells fit perfectly in the window. eg if cell size was
11 # 10 and window width or windowheight were 15 only 1.5 cells would
12 # fit.
13 assert Window_Width % Cell_Size == 0, "Window width must be a multiple of cell size."
14 # Ensuring that only whole integer number of cells fit perfectly in the window.
15 assert Window_Height % Cell_Size == 0, "Window height must be a multiple of cell size."
16 Cell_W = int(Window_Width / Cell_Size) # Cell Width
17 Cell_H = int(Window_Height / Cell_Size) # Cellc Height
18
19
20 White = (255, 255, 255)
21 Black = (0, 0, 0)
22 Red = (255, 0, 0) # Defining element colors for the program.
23 Green = (0, 255, 0)
24 DARKGreen = (0, 155, 0)
25 DARKGRAY = (40, 40, 40)
26 YELLOW = (255, 255, 0)
27 Red_DARK = (150, 0, 0)
28 BLUE = (0, 0, 255)
29 BLUE_DARK = (0, 0, 150)
30
31
32 BGCOLOR = Black # Background color
33
34
35 UP = 'up'
36 DOWN = 'down' # Defining keyboard keys.
37 LEFT = 'left'
38 RIGHT = 'right'
39
40 HEAD = 0 # Syntactic sugar: index of the snake's head
41
42
43 def main():
44 global SnakespeedCLOCK, DISPLAYSURF, BASICFONT
45
46 pygame.init()
47 SnakespeedCLOCK = pygame.time.Clock()
48 DISPLAYSURF = pygame.display.set_mode((Window_Width, Window_Height))
49 BASICFONT = pygame.font.Font('freesansbold.ttf', 18)
50 pygame.display.set_caption('Snake')
51
52 showStartScreen()
53 while True:
54 runGame()
55 showGameOverScreen()
56
57
58 def runGame():
59 # Set a random start point.
60 startx = random.randint(5, Cell_W - 6)
61 starty = random.randint(5, Cell_H - 6)
62 wormCoords = [{'x': startx, 'y': starty},
63 {'x': startx - 1, 'y': starty},
64 {'x': startx - 2, 'y': starty}]
65 direction = RIGHT
66
67 # Start the apple in a random place.
68 apple = getRandomLocation()
69
70 while True: # main game loop
71 for event in pygame.event.get(): # event handling loop
72 if event.type == QUIT:
73 terminate()
74 elif event.type == KEYDOWN:
75 if (event.key == K_LEFT) and direction != RIGHT:
76 direction = LEFT
77 elif (event.key == K_RIGHT) and direction != LEFT:
78 direction = RIGHT
79 elif (event.key == K_UP) and direction != DOWN:
80 direction = UP
81 elif (event.key == K_DOWN) and direction != UP:
82 direction = DOWN
83 elif event.key == K_ESCAPE:
84 terminate()
85
86 # check if the Snake has hit itself or the edge
87 if wormCoords[HEAD]['x'] == -1 or wormCoords[HEAD]['x'] == Cell_W or wormCoords[HEAD]['y'] == -1 or wormCoords[HEAD]['y'] == Cell_H:
88 return # game over
89 for wormBody in wormCoords[1:]:
90 if wormBody['x'] == wormCoords[HEAD]['x'] and wormBody['y'] == wormCoords[HEAD]['y']:
91 return # game over
92
93 # check if Snake has eaten an apply
94 if wormCoords[HEAD]['x'] == apple['x'] and wormCoords[HEAD]['y'] == apple['y']:
95 # don't remove worm's tail segment
96 apple = getRandomLocation() # set a new apple somewhere
97 else:
98 del wormCoords[-1] # remove worm's tail segment
99
100 # move the worm by adding a segment in the direction it is moving
101 if direction == UP:
102 newHead = {'x': wormCoords[HEAD]['x'],
103 'y': wormCoords[HEAD]['y'] - 1}
104 elif direction == DOWN:
105 newHead = {'x': wormCoords[HEAD]['x'],
106 'y': wormCoords[HEAD]['y'] + 1}
107 elif direction == LEFT:
108 newHead = {'x': wormCoords[HEAD][
109 'x'] - 1, 'y': wormCoords[HEAD]['y']}
110 elif direction == RIGHT:
111 newHead = {'x': wormCoords[HEAD][
112 'x'] + 1, 'y': wormCoords[HEAD]['y']}
113 wormCoords.insert(0, newHead)
114 DISPLAYSURF.fill(BGCOLOR)
115 drawGrid()
116 drawWorm(wormCoords)
117 drawApple(apple)
118 drawScore(len(wormCoords) - 3)
119 pygame.display.update()
120 SnakespeedCLOCK.tick(Snakespeed)
121
122
123 def drawPressKeyMsg():
124 pressKeySurf = BASICFONT.render('Press a key to play.', True, White)
125 pressKeyRect = pressKeySurf.get_rect()
126 pressKeyRect.topleft = (Window_Width - 200, Window_Height - 30)
127 DISPLAYSURF.blit(pressKeySurf, pressKeyRect)
128
129
130 def checkForKeyPress():
131 if len(pygame.event.get(QUIT)) > 0:
132 terminate()
133 keyUpEvents = pygame.event.get(KEYUP)
134 if len(keyUpEvents) == 0:
135 return None
136 if keyUpEvents[0].key == K_ESCAPE:
137 terminate()
138 return keyUpEvents[0].key
139
140
141 def showStartScreen():
142 titleFont = pygame.font.Font('freesansbold.ttf', 100)
143 titleSurf1 = titleFont.render('Lei python!', True, White, DARKGreen)
144 degrees1 = 0
145 degrees2 = 0
146 while True:
147 DISPLAYSURF.fill(BGCOLOR)
148 rotatedSurf1 = pygame.transform.rotate(titleSurf1, degrees1)
149 rotatedRect1 = rotatedSurf1.get_rect()
150 rotatedRect1.center = (Window_Width / 2, Window_Height / 2)
151 DISPLAYSURF.blit(rotatedSurf1, rotatedRect1)
152
153 drawPressKeyMsg()
154
155 if checkForKeyPress():
156 pygame.event.get() # clear event queue
157 return
158 pygame.display.update()
159 SnakespeedCLOCK.tick(Snakespeed)
160 degrees1 += 3 # rotate by 3 degrees each frame
161 degrees2 += 7 # rotate by 7 degrees each frame
162
163
164 def terminate():
165 pygame.quit()
166 sys.exit()
167
168
169 def getRandomLocation():
170 return {'x': random.randint(0, Cell_W - 1), 'y': random.randint(0, Cell_H - 1)}
171
172
173 def showGameOverScreen():
174 gameOverFont = pygame.font.Font('freesansbold.ttf', 100)
175 gameSurf = gameOverFont.render('Game', True, White)
176 overSurf = gameOverFont.render('Over', True, White)
177 gameRect = gameSurf.get_rect()
178 overRect = overSurf.get_rect()
179 gameRect.midtop = (Window_Width / 2, 10)
180 overRect.midtop = (Window_Width / 2, gameRect.height + 10 + 25)
181
182 DISPLAYSURF.blit(gameSurf, gameRect)
183 DISPLAYSURF.blit(overSurf, overRect)
184 drawPressKeyMsg()
185 pygame.display.update()
186 pygame.time.wait(500)
187 checkForKeyPress() # clear out any key presses in the event queue
188
189 while True:
190 if checkForKeyPress():
191 pygame.event.get() # clear event queue
192 return
193
194
195 def drawScore(score):
196 scoreSurf = BASICFONT.render('Score: %s' % (score), True, White)
197 scoreRect = scoreSurf.get_rect()
198 scoreRect.topleft = (Window_Width - 120, 10)
199 DISPLAYSURF.blit(scoreSurf, scoreRect)
200
201
202 def drawWorm(wormCoords):
203 for coord in wormCoords:
204 x = coord['x'] * Cell_Size
205 y = coord['y'] * Cell_Size
206 wormSegmentRect = pygame.Rect(x, y, Cell_Size, Cell_Size)
207 pygame.draw.rect(DISPLAYSURF, DARKGreen, wormSegmentRect)
208 wormInnerSegmentRect = pygame.Rect(
209 x + 4, y + 4, Cell_Size - 8, Cell_Size - 8)
210 pygame.draw.rect(DISPLAYSURF, Green, wormInnerSegmentRect)
211
212
213 def drawApple(coord):
214 x = coord['x'] * Cell_Size
215 y = coord['y'] * Cell_Size
216 appleRect = pygame.Rect(x, y, Cell_Size, Cell_Size)
217 pygame.draw.rect(DISPLAYSURF, Red, appleRect)
218
219
220 def drawGrid():
221 for x in range(0, Window_Width, Cell_Size): # draw vertical lines
222 pygame.draw.line(DISPLAYSURF, DARKGRAY, (x, 0), (x, Window_Height))
223 for y in range(0, Window_Height, Cell_Size): # draw horizontal lines
224 pygame.draw.line(DISPLAYSURF, DARKGRAY, (0, y), (Window_Width, y))
225
226
227 if __name__ == '__main__':
228 try:
229 main()
230 except SystemExit:
231 pass
