import random
import pygame
import sys
from pygame.locals import *
Snakespeed = 17
Window_Width = 800
Window_Height = 500
Cell_Size = 20 # Width and height of the cells
assert Window_Width % Cell_Size == 0, "Window width must be a multiple of cell size."
assert Window_Height % Cell_Size == 0, "Window height must be a multiple of cell size."
Cell_W = int(Window_Width / Cell_Size) # Cell Width
Cell_H = int(Window_Height / Cell_Size) # Cellc Height
White = (255, 255, 255)
Black = (0, 0, 0)
Red = (255, 0, 0) # Defining element colors for the program.
Green = (0, 255, 0)
DARKGreen = (0, 155, 0)
DARKGRAY = (40, 40, 40)
YELLOW = (255, 255, 0)
Red_DARK = (150, 0, 0)
BLUE = (0, 0, 255)
BLUE_DARK = (0, 0, 150)
BGCOLOR = Black # Background color
UP = 'up'
DOWN = 'down' # Defining keyboard keys.
LEFT = 'left'
RIGHT = 'right'
HEAD = 0 # Syntactic sugar: index of the snake's head
def main():
global SnakespeedCLOCK, DISPLAYSURF, BASICFONT
pygame.init()
SnakespeedCLOCK = pygame.time.Clock()
DISPLAYSURF = pygame.display.set_mode((Window_Width, Window_Height))
BASICFONT = pygame.font.Font('freesansbold.ttf', 18)
pygame.display.set_caption('Snake')
showStartScreen()
while True:
runGame()
showGameOverScreen()
def runGame():
# Set a random start point.
startx = random.randint(5, Cell_W - 6)
starty = random.randint(5, Cell_H - 6)
wormCoords = [{'x': startx, 'y': starty},
{'x': startx - 1, 'y': starty},
{'x': startx - 2, 'y': starty}]
direction = RIGHT
# Start the apple in a random place.
apple = getRandomLocation()
while True: # main game loop
for event in pygame.event.get(): # event handling loop
if event.type == QUIT:
terminate()
elif event.type == KEYDOWN:
if (event.key == K_LEFT) and direction != RIGHT:
direction = LEFT
elif (event.key == K_RIGHT) and direction != LEFT:
direction = RIGHT
elif (event.key == K_UP) and direction != DOWN:
direction = UP
elif (event.key == K_DOWN) and direction != UP:
direction = DOWN
elif event.key == K_ESCAPE:
terminate()
# check if the Snake has hit itself or the edge
if wormCoords[HEAD]['x'] == -1 or wormCoords[HEAD]['x'] == Cell_W or wormCoords[HEAD]['y'] == -1 or wormCoords[HEAD]['y'] == Cell_H:
return # game over
for wormBody in wormCoords[1:]:
if wormBody['x'] == wormCoords[HEAD]['x'] and wormBody['y'] == wormCoords[HEAD]['y']:
return # game over
# check if Snake has eaten an apply
if wormCoords[HEAD]['x'] == apple['x'] and wormCoords[HEAD]['y'] == apple['y']:
# don't remove worm's tail segment
apple = getRandomLocation() # set a new apple somewhere
else:
del wormCoords[-1] # remove worm's tail segment
# move the worm by adding a segment in the direction it is moving
if direction == UP:
newHead = {'x': wormCoords[HEAD]['x'],
'y': wormCoords[HEAD]['y'] - 1}
elif direction == DOWN:
newHead = {'x': wormCoords[HEAD]['x'],
'y': wormCoords[HEAD]['y'] + 1}
elif direction == LEFT:
newHead = {'x': wormCoords[HEAD][
'x'] - 1, 'y': wormCoords[HEAD]['y']}
elif direction == RIGHT:
newHead = {'x': wormCoords[HEAD][
'x'] + 1, 'y': wormCoords[HEAD]['y']}
wormCoords.insert(0, newHead)
DISPLAYSURF.fill(BGCOLOR)
drawGrid()
drawWorm(wormCoords)
drawApple(apple)
drawScore(len(wormCoords) - 3)
pygame.display.update()
SnakespeedCLOCK.tick(Snakespeed)
def drawPressKeyMsg():
pressKeySurf = BASICFONT.render('Press a key to play.', True, White)
pressKeyRect = pressKeySurf.get_rect()
pressKeyRect.topleft = (Window_Width - 200, Window_Height - 30)
DISPLAYSURF.blit(pressKeySurf, pressKeyRect)
def checkForKeyPress():
if len(pygame.event.get(QUIT)) > 0:
terminate()
keyUpEvents = pygame.event.get(KEYUP)
if len(keyUpEvents) == 0:
return None
if keyUpEvents[0].key == K_ESCAPE:
terminate()
return keyUpEvents[0].key
def showStartScreen():
titleFont = pygame.font.Font('freesansbold.ttf', 100)
titleSurf1 = titleFont.render('Snake!', True, White, DARKGreen)
degrees1 = 0
degrees2 = 0
while True:
DISPLAYSURF.fill(BGCOLOR)
rotatedSurf1 = pygame.transform.rotate(titleSurf1, degrees1)
rotatedRect1 = rotatedSurf1.get_rect()
rotatedRect1.center = (Window_Width / 2, Window_Height / 2)
DISPLAYSURF.blit(rotatedSurf1, rotatedRect1)
drawPressKeyMsg()
if checkForKeyPress():
pygame.event.get() # clear event queue
return
pygame.display.update()
SnakespeedCLOCK.tick(Snakespeed)
degrees1 += 3 # rotate by 3 degrees each frame
degrees2 += 7 # rotate by 7 degrees each frame
def terminate():
pygame.quit()
sys.exit()
def getRandomLocation():
return {'x': random.randint(0, Cell_W - 1), 'y': random.randint(0, Cell_H - 1)}
def showGameOverScreen():
gameOverFont = pygame.font.Font('freesansbold.ttf', 100)
gameSurf = gameOverFont.render('Game', True, White)
overSurf = gameOverFont.render('Over', True, White)
gameRect = gameSurf.get_rect()
overRect = overSurf.get_rect()
gameRect.midtop = (Window_Width / 2, 10)
overRect.midtop = (Window_Width / 2, gameRect.height + 10 + 25)
DISPLAYSURF.blit(gameSurf, gameRect)
DISPLAYSURF.blit(overSurf, overRect)
drawPressKeyMsg()
pygame.display.update()
pygame.time.wait(500)
checkForKeyPress() # clear out any key presses in the event queue
while True:
if checkForKeyPress():
pygame.event.get() # clear event queue
return
def drawScore(score):
scoreSurf = BASICFONT.render('Score: %s' % (score), True, White)
scoreRect = scoreSurf.get_rect()
scoreRect.topleft = (Window_Width - 120, 10)
DISPLAYSURF.blit(scoreSurf, scoreRect)
def drawWorm(wormCoords):
for coord in wormCoords:
x = coord['x'] * Cell_Size
y = coord['y'] * Cell_Size
wormSegmentRect = pygame.Rect(x, y, Cell_Size, Cell_Size)
pygame.draw.rect(DISPLAYSURF, DARKGreen, wormSegmentRect)
wormInnerSegmentRect = pygame.Rect(
x + 4, y + 4, Cell_Size - 8, Cell_Size - 8)
pygame.draw.rect(DISPLAYSURF, Green, wormInnerSegmentRect)
def drawApple(coord):
x = coord['x'] * Cell_Size
y = coord['y'] * Cell_Size
appleRect = pygame.Rect(x, y, Cell_Size, Cell_Size)
pygame.draw.rect(DISPLAYSURF, Red, appleRect)
def drawGrid():
for x in range(0, Window_Width, Cell_Size): # draw vertical lines
pygame.draw.line(DISPLAYSURF, DARKGRAY, (x, 0), (x, Window_Height))
for y in range(0, Window_Height, Cell_Size): # draw horizontal lines
pygame.draw.line(DISPLAYSURF, DARKGRAY, (0, y), (Window_Width, y))
if name == 'main':
try:
main()
except SystemExit:
pass
