当我在此代码中左键单击时，如何使子弹射向我的鼠标？

问题描述

    import pygame
import random
import math
from pygame import mixer


pygame.init()

screen = pygame.display.set_mode((1280,720)) 
background = pygame.image.load('1264.jpg') 
background = pygame.transform.scale(background,(1290,720)) 

pygame.display.set_caption("FlySwapper") 
icon = pygame.image.load('logo.png') 
pygame.display.set_icon(icon) 

playerImg = pygame.image.load('Frosk.png') 
playerX = 580 
playerY = 550 
playerX_change = 0 
playerY_change = 0 

enemyImg = []
enemyX = []
enemyY = []
enemyX_change = []
enemyY_change = []
num_of_enemies = 6



for i in range(num_of_enemies):
    enemyImg.append(pygame.image.load('flue.png'))
    enemyX.append(random.randint(0,1290)) 
    enemyY.append(random.randint(0,310)) 
    enemyX_change.append(0.5) 
    enemyY_change.append(0.5)


bulletImg = pygame.image.load('skudd.png')
bulletX = 0
bulletY = 0
bulletX_change = 2
bulletY_change = 2
bullet_state = "ready"



def player(x,y): 
    screen.blit(playerImg,(x,y))

def enemy(x,y,i):
    screen.blit(enemyImg[i],y))

def fire_bullet(x,y):
    global bullet_state
    bullet_state = "fire"
    screen.blit(bulletImg,(x + 35,y + 10))



running = True  
while running:

    screen.blit(background,(0,0)) 

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

     

        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_a:
                playerX_change = -1
            if event.key == pygame.K_d:
                playerX_change = 1
            if event.key == pygame.K_w:
                playerY_change = -1
            if event.key == pygame.K_s:
                playerY_change = 1

        if event.type == pygame.KEYUP:
            if event.key == pygame.K_a or event.key == pygame.K_d:
                playerX_change = 0
        if event.type == pygame.KEYUP:
            if event.key == pygame.K_w or event.key == pygame.K_s:
                playerY_change = 0

   
        LEFT = 1
        RIGHT = 3

        if event.type == pygame.MOUSEBUTTONUP and event.button == LEFT:
            if bullet_state == "ready":
                #bullet_Sound = mixer.sound('.wav')
                #bullet_Sound.play()
                bulletX = playerX
                bulletY = playerY
                fire_bullet(bulletX,bulletY)

    playerX += playerX_change
    playerY += playerY_change

    if playerX <= 0:
        playerX = 0
    elif playerX >= 1150:
        playerX = 1150
    if playerY <= 310: 
        playerY = 310
    elif playerY >= 590:
        playerY = 590

    player(playerX,playerY)



    for i in range(num_of_enemies):
      
        enemyX[i] += enemyX_change[i]
        enemyY[i] += enemyY_change[i]

        if enemyX[i] <= 0:
            enemyX_change[i] = 0.5
        elif enemyX[i] >= 1150:
            enemyX_change[i] = -0.5
        if enemyY[i] <= 0:
            enemyY_change[i] = 0.5
        elif enemyY[i] >= 590:
            enemyY_change[i] = -0.5


 
        enemy(enemyX[i],enemyY[i],i)


    if bulletY <= 0:
        bullet_state = "ready"
    if bullet_state == "fire":
        fire_bullet(bulletX,bulletY)
        bulletY -= bulletY_change

   
    pygame.display.update()

几个星期以来，我一直试图让子弹通过左键点击我的鼠标，我的老师显然无法帮助我，而且我对 python 还很陌生。 我知道我已经让子弹只在这段代码中前进，但我计划将其更改为稍后点击鼠标。

如果这是对我的问题的错误解释，我很抱歉。

解决方法

点击鼠标时，需要计算从子弹起始位置到鼠标位置的归一化方向向量（Unit vector）。定义子弹的速度并将方向向量乘以速度：

dx = event.pos[0] - bulletX
dy = event.pos[1] - bulletY
dist = math.sqrt(dx*dx + dy*dy)
bulletX_change = bullet_speed * dx/dist 
bulletY_change = bullet_speed * dy/dist 

---

相关变化：

def fire_bullet(x,y):
    screen.blit(bulletImg,(x + 35,y + 10))

running = True  
while running:
    # [...]

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        # [...]

        if event.type == pygame.MOUSEBUTTONUP and event.button == LEFT:
            if bullet_state == "ready":
                #bullet_Sound = mixer.Sound('.wav')
                #bullet_Sound.play()
                bulletX = playerX
                bulletY = playerY
                bullet_state = "fire"
                dx = event.pos[0] - bulletX
                dy = event.pos[1] - bulletY
                dist = math.sqrt(dx*dx + dy*dy)
                bulletX_change = bullet_speed * dx/dist 
                bulletY_change = bullet_speed * dy/dist 

    # [...]

    if playerX < 0 or bulletY < 0 or playerX > 1280 or bulletY > 720:
        bullet_state = "ready"
    if bullet_state == "fire":
        bulletX += bulletX_change
        bulletY += bulletY_change
        fire_bullet(bulletX,bulletY)

    pygame.display.update()