如何防止多颗子弹同时发射
在原始代码中，由于 pygame 的存在，会同时发射多颗子弹只要按下某个键，.key.get_pressed() 函数就会返回 True。此行为适用于控制玩家移动，但不适用于发射子弹，每次按下按键时您只希望发射一颗子弹。
要解决此问题，我们可以利用 pygame.KEYDOWN事件，仅在首次按下某个键时发生一次。通过使用这个事件而不是pygame.key.get_pressed()，我们可以确保按下空格键时只发射一颗子弹。
此外，我们可以实现一个简单的冷却机制来防止快速发射子弹射击。这可以通过引入一个名为 next_bullet_threshold 的变量来完成，该变量表示下一颗子弹可以发射的最早时间。每次发射子弹时，我们都会将 next_bullet_threshold 更新为当前时间加上所需的冷却时间。通过检查当前时间是否大于 next_bullet_threshold，我们可以防止任何子弹在所需的冷却时间之外发射。
以下是已实现冷却机制的修改后的代码：
<code class="python">import pygame
pygame.init()
red = 255,0,0
blue = 0,0,255
black = 0,0,0
screenWidth = 800
screenHeight = 600
gameDisplay = pygame.display.set_mode((screenWidth,screenHeight)) ## screen width and height
pygame.display.set_caption('JUST SOME BLOCKS') ## set my title of the window
clock = pygame.time.Clock()
class player(): ## has all of my attributes for player 1
def __init__(self,x,y,width,height):
self.x = x
self.y = y
self.height = height
self.width = width
self.vel = 5
self.left = False
self.right = False
self.up = False
self.down = False
class projectile(): ## projectile attributes
def __init__(self,x,y,radius,colour,facing):
self.x = x
self.y = y
self.radius = radius
self.facing = facing
self.colour = colour
self.vel = 8 * facing # speed of bullet * the direction (-1 or 1)
def draw(self,gameDisplay):
pygame.draw.circle(gameDisplay, self.colour , (self.x,self.y),self.radius) ## put a 1 after that to make it so the circle is just an outline
def redrawGameWindow():
for bullet in bullets: ## draw bullets
bullet.draw(gameDisplay)
pygame.display.update()
#mainloop
player1 = player(300,410,50,70) # moves the stuff from the class (when variables are user use player1.var)
bullets = []
run = True
next_bullet_threshold = 0 # Initialize the cooldown threshold
bullet_cooldown = 500 # Set the desired cooldown period in milliseconds
while run == True:
clock.tick(27)
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
for bullet in bullets:
if bullet.x < screenWidth and bullet.x > 0 and bullet.y < screenHeight and bullet.y > 0: ## makes sure bullet does not go off screen
bullet.x += bullet.vel
else:
bullets.pop(bullets.index(bullet))
keys = pygame.key.get_pressed() ## check if a key has been pressed
## red player movement
if keys[pygame.K_w] and player1.y > player1.vel: ## check if that key has been pressed down (this will check for w) and checks for boundry
player1.y -= player1.vel ## move the shape in a direction
player1.up = True
player1.down = False
if keys[pygame.K_a] and player1.x > player1.vel: ### this is for a
player1.x -= player1.vel
player1.left = True
player1.right = False
if keys[pygame.K_s] and player1.y < screenHeight - player1.height - player1.vel: ## this is for s
player1.y += player1.vel
player1.down = True
player1.up = False
if keys[pygame.K_d] and player1.x < screenWidth - player1.width - player1.vel: ## this is for d
player1.x += player1.vel
player1.right = True
player1.left = False
if keys[pygame.K_SPACE]: # shooting with the space bar
current_time = pygame.time.get_ticks()
if current_time >= next_bullet_threshold: # Check the cooldown timer
if player1.left == True: ## handles the direction of the bullet
facing = -1
else:
facing = 1
if len(bullets) < 5: ## max amounts of bullets on screen
bullets.append(projectile(player1.x + player1.width //2 ,player1.y + player1.height//2,6,black,facing)) ##just like calling upon a function
next_bullet_threshold = current_time + bullet_cooldown # Update cooldown timer
## level
gameDisplay.fill((0,255,0)) ### will stop the shape from spreading around and will have a background
pygame.draw.rect(gameDisplay,(red),(player1.x,player1.y,player1.width,player1.height)) ## draw player
pygame.display.update()
redrawGameWindow()
pygame.quit()</code>以上是如何实现冷却机制来防止子弹过度射击？的详细内容。更多信息请关注PHP中文网其他相关文章！
