这是我用pygame创建的第一款游戏，它基本上都是蛇。
请不要介意我的可怕评论。
## William's Snake Game
import pygame
import time
import random
pygame.init()
##Global variables
# Colours
white = (255, 255, 255)
black = (0, 0, 0)
red = (255, 0, 0)
green = (0, 155, 0)
bground = (204, 204, 0)
# Display vars.
display_width = 800
display_height = 600
# Variables
gameDisplay = pygame.display.set_mode((display_width, display_height)) ##resolution, note that this is a tuple.
pygame.display.set_caption("Snake VS Apple") # Title at the top of the screen
icon = pygame.image.load('logoapple32x32.png') # Loads the icon for the top left
pygame.display.set_icon(icon) # Sets the icon for the top left
snakeHeadImg = pygame.image.load("snakeHead.png") # Loads the image for the snake head
appleImg = pygame.image.load("apple20x20.png") # Loads the image for the apple
appleThickness = 20 # Defines how thick apple will be. Note to self: This is changable
clock = pygame.time.Clock() # Starts clocking the game, used later for FPS
blockSize = 20 # Defines how big the snake will be. Changing this will mess up collision detection.
FPS = 15 # Frames per second. Called at the bottom of script
smallfont = pygame.font.SysFont("arial", 25) ## format: ("font", fontsize)
medfont = pygame.font.SysFont("arial", 40) ##
largefont = pygame.font.SysFont("arial", 80) ##
direction = "right" # Starting direction of snake, used in main gameLoop
##
def pauseGame():
gameisPaused = True
while gameisPaused:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
quit()
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_ESCAPE:
gameisPaused = False
elif event.key == pygame.K_q:
pygame.quit()
quit()
gameDisplay.fill(white)
message_to_screen("Paused",
black,
-100,
size="large")
message_to_screen("Press ESC to continue or Q to quit.",
black,
25,
size="small")
pygame.display.update()
clock.tick(5)
def text_objects(text, color, size): # Function to render text
if size == "small":
textSurface = smallfont.render(text, True, color)
elif size == "medium":
textSurface = medfont.render(text, True, color)
elif size == "large":
textSurface = largefont.render(text, True, color)
return textSurface, textSurface.get_rect()
def message_to_screen(msg, color, y_displace=0, size="medium"): # Function to blit (draw) text to surface
textSurf, textRect = text_objects(msg, color, size)
textRect.center = (display_width / 2), (display_height / 2) + y_displace
gameDisplay.blit(textSurf, textRect)
##
def score(score):
text = smallfont.render("Score: " + str(score), True, black)
gameDisplay.blit(text, [0, 0])
def randAppleGen(): # Function to generate random apples
randAppleX = round(
random.randrange(0, display_width - appleThickness)) # /10.0)*10.0 ##Create another rand X value for new apple
randAppleY = round(
random.randrange(0, display_height - appleThickness)) # /10.0)*10.0 ##Create another rand Y value for new apple
return randAppleX, randAppleY
def gameIntro(): # Function for game menu.
intro = True
while intro: # Event handling during menu
for eachEvent in pygame.event.get():
if eachEvent.type == pygame.QUIT:
pygame.quit()
quit()
if eachEvent.type == pygame.KEYDOWN:
if eachEvent.key == pygame.K_c:
gameLoop()
if eachEvent.key == pygame.K_q:
pygame.quit()
quit()
# Text displayed in menu
gameDisplay.fill(white)
message_to_screen("Welcome to Slither",
green,
-90,
"large")
message_to_screen("The more apples you eat, the longer you are",
black,
100)
message_to_screen("The objective of the game is to eat red apples",
black,
0,
"small")
message_to_screen("If you run into yourself, or the edges, you die!",
black,
30,
"small")
message_to_screen("Press C to play or Q to quit.",
black,
180)
pygame.display.update()
clock.tick(500)
def snake(blockSize, snakeList): # Function to draw snake
if direction == "right":
head = pygame.transform.rotate(snakeHeadImg,
270) # In gameLoop, right,left,up,down are used to change direction of snakeHead
elif direction == "left":
head = pygame.transform.rotate(snakeHeadImg, 90)
elif direction == "up":
head = snakeHeadImg
elif direction == "down":
head = pygame.transform.rotate(snakeHeadImg, 180)
gameDisplay.blit(head, (snakeList[-1][0], snakeList[-1][1])) ##???
for XandY in snakeList[:-1]:
pygame.draw.rect(gameDisplay, green,
[XandY[0], XandY[1], blockSize, blockSize]) ##width height, width height, drawing
##Main Game Loop
def gameLoop():
global direction ## Make direction a global var. Important
# Local variables
gameExit = False
gameOver = False
lead_x = display_width / 2
lead_y = display_height / 2
lead_x_change = 10
lead_y_change = 0
snakeList = []
snakeLength = 3
randAppleX, randAppleY = randAppleGen() # Generate apples. Calls randAppleGen()
# Main Game Loop ##eventHandler
while not gameExit:
snakeHead = [] # Creates list snakeHead
snakeHead.append(lead_x) # Appends snakeHead x value to list
snakeHead.append(lead_y) # Appends snakeHead y value to list
snakeList.append(snakeHead) # Appends coordinates of snakeHead x,y to list
while gameOver == True: # Handles game over
gameDisplay.fill(white)
message_to_screen("Game over",
red,
-50,
size="large")
message_to_screen("Press C to play again or Q to quit",
black,
50,
size="medium")
pygame.display.update()
for event in pygame.event.get(): # eventHandler for loss screen
if event.type == pygame.QUIT:
pygame.quit()
quit()
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_q:
gameExit = True
gameOver = False
if event.key == pygame.K_c:
direction = "right"
gameLoop()
for event in pygame.event.get(): # eventHandler for keyboard events during game
if event.type == pygame.QUIT:
gameExit = True
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_LEFT or event.key == pygame.K_a: # Each of these handles either arrow keys or WASD key events.
lead_x_change = -blockSize
lead_y_change = 0
direction = "left"
elif event.key == pygame.K_RIGHT or event.key == pygame.K_d:
lead_x_change = blockSize
lead_y_change = 0
direction = "right"
elif event.key == pygame.K_UP or event.key == pygame.K_w:
lead_y_change = -blockSize
lead_x_change = 0
direction = "up"
elif event.key == pygame.K_DOWN or event.key == pygame.K_s:
lead_y_change = blockSize
lead_x_change = 0
direction = "down"
elif event.key == pygame.K_ESCAPE:
pauseGame()
# Checks if user has hit screen boundaries.
if lead_x >= display_width or lead_x < 0 or lead_y >= display_height or lead_y < 0: # If user hits display boundaries
gameOver = True # They lose
lead_x += lead_x_change # Ensures continous movement of the snake
lead_y += lead_y_change
# Drawing
gameDisplay.fill(bground) # Fills the display background with predefined bground colour (defined at the top)
gameDisplay.blit(appleImg,
(randAppleX, randAppleY)) ##Draws the apple using the appleImg, at random coordinates.
if len(
snakeList) > snakeLength: # If the length of the list of snake body coordinates is greater than the length
del snakeList[0] # Delete the oldest value in the list (as the snake is constantly moving)
for eachSegment in snakeList[:-1]: # For each coordinate in snakeList
if eachSegment == snakeHead: # If the segment touches the snakeHead
## gameDisplay.fill(bground)
## snake(blockSize, snakeList)
##
## pygame.display.update
time.sleep(0.3)
gameOver = True # Game over
snake(blockSize, snakeList) ##Creates snake using function snake
score(snakeLength - 3) # Displays score (it minuses 3 because the snake starts at 3)
pygame.display.update() ##Updates to screen
## COLLISION DETECTION
if lead_x + blockSize > randAppleX and lead_x < randAppleX + appleThickness:
if lead_y + blockSize > randAppleY and lead_y < randAppleY + appleThickness:
randAppleX, randAppleY = randAppleGen()
snakeLength += 1
clock.tick(FPS)
pygame.quit()
quit()
##update screen
##
gameIntro()
gameLoop()
##Code goes above.
我有一个问题，如果我的蛇向右走，然后它向左转，我的蛇就会撞到自己身上，游戏就会结束。
我想设计这个，所以当我的蛇走向正确时，它不能简单地向左转，撞到自己并结束游戏。因此，当它向右转时，它只能向上，向下或保持正确。所以简单地说，我想做到这一点，它不能倒退到自己身上。
我自己尝试过编码，我尝试了很多方法但没有任何效果。
请帮助!!
答案 0 :(得分：2)
在不改变代码的情况下（并且不进行测试），获得所需内容的简单方法是为密钥检查添加另一个条件。如果你改变相关的代码部分如下，一切都应该没问题：
for event in pygame.event.get(): # eventHandler for keyboard events during game
if event.type == pygame.QUIT:
gameExit = True
if event.type == pygame.KEYDOWN:
if (event.key == pygame.K_LEFT or event.key == pygame.K_a) and direction != "right": # Each of these handles either arrow keys or WASD key events.
lead_x_change = -blockSize
lead_y_change = 0
direction = "left"
elif (event.key == pygame.K_RIGHT or event.key == pygame.K_d) and direction != "left":
lead_x_change = blockSize
lead_y_change = 0
direction = "right"
elif (event.key == pygame.K_UP or event.key == pygame.K_w) and direction != "down":
lead_y_change = -blockSize
lead_x_change = 0
direction = "up"
elif (event.key == pygame.K_DOWN or event.key == pygame.K_s) and direction != "up":
lead_y_change = blockSize
lead_x_change = 0
direction = "down"
elif event.key == pygame.K_ESCAPE:
pauseGame()
注意or'd键检查周围的括号！