无法在pygame中添加多个敌人

Question

我正在制作一款类似《太空入侵者》的游戏，最近我遇到了一个错误，说"I"是未定义的，当时我将敌人的变量存储到列表中，以便通过"for I in range(num_of_evenues("循环向游戏中添加更多敌人。我使用的是Python 3.8和PyCharm。我现在说了所有的话，但我必须继续写才能发布这个。

import pygame
import random
import math
# Initiate pygame
pygame.init()
# Display the game window
screen = pygame.display.set_mode((800, 600))
# Enemies
enemySprite = []
enemyX = []
enemyY = []
enemyX_change = []
enemyY_change = []
num_of_enemies = 6
for i in range(num_of_enemies):
enemySprite.append(pygame.image.load('enemy.png'))
enemyX.append(random.randint(0, 736))
enemyY.append(random.randint(50, 150))
enemyX_change.append(4)
enemyY_change.append(20)
def enemy(x, y, i):
screen.blit(enemySprite[i], (x, y))
def isCollision(enemyX, enemyY, bulletX, bulletY):
distance = math.sqrt((math.pow(enemyX - bulletX, 2)) + (math.pow(enemyY - bulletY, 2)))
if distance < 27:
return True
else:
return False
# Game Loop
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
for i in range(num_of_enemies):
# Enemies movement
enemyX[i] += enemyX_change[i]
# Prevents the enemies from going off the border
if enemyX[i] <= 0 or enemyX[i] >= 736:
enemyX_change[i] *= -1
enemyY[i] += enemyY_change[i]
# Collision
collision = isCollision(enemyX[i], enemyY[i], bulletX, bulletY)
if collision:
bulletY = 480
bullet_state = 'ready'
score += 1
print(score)
enemyX[i] = random.randint(0, 736)
enemyY[i] = random.randint(50, 150)
enemy(enemyX[i], enemyY[i], i)
pygame.display.update()

Answer 1

这是缩进的问题。您必须在for循环中使用敌人逻辑，它迭代敌人，而不是主应用程序循环
此外，未定义bulletX、bulletY。您必须在主应用程序循环之前定义这些变量
在绘制敌人并在单独的循环中绘制敌人之前，请清除显示或绘制背景图像
使用pygame.time.Clock()控制每秒帧数。

bulletX, bulletY = 0, 0
# Game Loop
clock = pygame.time.Clock()
running = True
while running:
clock.tick(60)
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
for i in range(num_of_enemies):
# Enemies movement
enemyX[i] += enemyX_change[i]
# Prevents the enemies from going off the border
if enemyX[i] <= 0 or enemyX[i] >= 736:
enemyX_change[i] *= -1
enemyY[i] += enemyY_change[i]
# Collision
collision = isCollision(enemyX[i], enemyY[i], bulletX, bulletY)
if collision:
bulletY = 480
bullet_state = 'ready'
score += 1
print(score)
enemyX[i] = random.randint(0, 736)
enemyY[i] = random.randint(50, 150)
# draw background image
# [...]
# d raw enemies
for i in range(num_of_enemies):
enemy(enemyX[i], enemyY[i], i)
# update display
pygame.display.update()